for Journals by Title or ISSN
for Articles by Keywords
help
  Subjects -> COMPUTER SCIENCE (Total: 2053 journals)
    - ANIMATION AND SIMULATION (30 journals)
    - ARTIFICIAL INTELLIGENCE (99 journals)
    - AUTOMATION AND ROBOTICS (102 journals)
    - CLOUD COMPUTING AND NETWORKS (65 journals)
    - COMPUTER ARCHITECTURE (9 journals)
    - COMPUTER ENGINEERING (10 journals)
    - COMPUTER GAMES (16 journals)
    - COMPUTER PROGRAMMING (27 journals)
    - COMPUTER SCIENCE (1198 journals)
    - COMPUTER SECURITY (44 journals)
    - DATA BASE MANAGEMENT (14 journals)
    - DATA MINING (33 journals)
    - E-BUSINESS (22 journals)
    - E-LEARNING (29 journals)
    - ELECTRONIC DATA PROCESSING (22 journals)
    - IMAGE AND VIDEO PROCESSING (39 journals)
    - INFORMATION SYSTEMS (108 journals)
    - INTERNET (93 journals)
    - SOCIAL WEB (51 journals)
    - SOFTWARE (34 journals)
    - THEORY OF COMPUTING (8 journals)

COMPUTER SCIENCE (1198 journals)

The end of the list has been reached or no journals were found for your choice.
Journal Cover Control Engineering Practice
  [SJR: 1.354]   [H-I: 84]   [44 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0967-0661
   Published by Elsevier Homepage  [3175 journals]
  • Multiple parameter-dependent robust control of miniaturized optical image
           stabilizers
    • Authors: Pan Zhao; Ryozo Nagamune; Mu Chiao
      Pages: 1 - 11
      Abstract: Publication date: July 2018
      Source:Control Engineering Practice, Volume 76
      Author(s): Pan Zhao, Ryozo Nagamune, Mu Chiao
      This paper presents the design of multiple parameter-dependent robust controllers for mass-produced miniaturized optical image stabilizers (OIS’s), which are used to minimize the image blur in mobile devices caused by hand-induced camera shake. The dynamics of batch-fabricated OIS’s with inevitable product variations is represented by a set of linear models, parameterized by two product-dependent natural frequencies and one uncertain gain. It turns out that the natural frequencies for each OIS product are difficult to determine accurately, and thus assumed to be estimated with errors. The controller is designed to be parameter-dependent on estimated natural frequencies, as well as to be robust against both estimation errors of the natural frequencies and the gain uncertainty. Experimental results on large-scale prototypes demonstrate that the proposed controller outperforms a conventional parameter-independent robust controller as well as a single parameter-dependent robust controller. Specifically, the proposed controller yields more than 27% improvement over the conventional robust controller in terms of lens-tilting tracking performance.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.03.013
      Issue No: Vol. 76 (2018)
       
  • 2D visual area coverage and path planning coupled with camera footprints
    • Authors: Sina Sharif Mansouri; Christoforos Kanellakis; George Georgoulas; Dariusz Kominiak; Thomas Gustafsson; George Nikolakopoulos
      Pages: 1 - 16
      Abstract: Publication date: June 2018
      Source:Control Engineering Practice, Volume 75
      Author(s): Sina Sharif Mansouri, Christoforos Kanellakis, George Georgoulas, Dariusz Kominiak, Thomas Gustafsson, George Nikolakopoulos
      Unmanned Aerial Vehicles (UAVs) equipped with visual sensors are widely used in area coverage missions. Guaranteeing full coverage coupled with camera footprint is one of the most challenging tasks, thus, in the presented novel approach a coverage path planner for the inspection of 2D areas is established, a 3 Degree of Freedom (DoF) camera movement is considered and the shortest path from the taking off to the landing station is generated, while covering the target area. The proposed scheme requires a priori information about the boundaries of the target area and generates the paths in an offline process. The efficacy and the overall performance of the proposed method has been experimentally evaluated in multiple indoor inspection experiments with convex and non convex areas. Furthermore, the image streams collected during the coverage tasks were post-processed using image stitching for obtaining a single overview of the covered scene.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.03.011
      Issue No: Vol. 75 (2018)
       
  • Visual estimation of deviations for the civil aircraft landing
    • Authors: V. Gibert; F. Plestan; L. Burlion; J. Boada-Bauxell; A. Chriette
      Pages: 17 - 25
      Abstract: Publication date: June 2018
      Source:Control Engineering Practice, Volume 75
      Author(s): V. Gibert, F. Plestan, L. Burlion, J. Boada-Bauxell, A. Chriette
      This paper presents a new scheme for the visual estimation of deviation of a system with respect to an object for which no feature is known (position, dimensions, …). This scheme is based on nonlinear observers and, thanks to an adequate combination of the visual information, requires reduced computation for its design. It is evaluated on a scenario describing the landing of an aircraft on an unknown runway and is validated with synthetic images.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.03.004
      Issue No: Vol. 75 (2018)
       
  • Short-term wave force prediction for wave energy converter control
    • Authors: Hoai-Nam Nguyen; Paolino Tona
      Pages: 26 - 37
      Abstract: Publication date: June 2018
      Source:Control Engineering Practice, Volume 75
      Author(s): Hoai-Nam Nguyen, Paolino Tona
      Given the importance of wave excitation force prediction in most advanced control schemes for wave energy converters, where every new wave force estimation becomes available every fraction of second, the main objective of this paper is to perform a short-term wave prediction that can meet a trade-off between low computational complexity, limited memory usage and accuracy. To this aim, two prediction algorithms are proposed using Kalman filtering theory. The proposed prediction methods are evaluated by using real measurements.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.03.007
      Issue No: Vol. 75 (2018)
       
  • An expert fuzzy system for improving safety on pedestrian crossings by
           means of visual feedback
    • Authors: Javier Albusac; D. Vallejo; J.J. Castro-Schez; C. Gzlez-Morcillo
      Pages: 38 - 54
      Abstract: Publication date: June 2018
      Source:Control Engineering Practice, Volume 75
      Author(s): Javier Albusac, D. Vallejo, J.J. Castro-Schez, C. Gzlez-Morcillo
      Despite the continuous measures taken in large cities to improve road safety, pedestrian run-overs are still some of the main problems. In this paper an expert system is presented, whose aim is to reduce the number of run overs on pedestrian crossings with a luminous reinforcement system. An expert fuzzy system analyses the speed approaching vehicles travel at and the distance between them and pedestrians, in order to determine the degree of danger. This analysis is used to calculate the number of barriers that must be lit, from which position and their blinking frequency. Moreover, the system can recommend a speed to the driver so that he or she can return to a state of normality if this has been altered. The barriers light up according to how the driver behaves. If he or she slows down gradually on seeing a pedestrian, the barriers turn off at a similar pace. However, if the vehicle is approaching too fast, a path of light will be shown from the actual position of the pedestrian towards the vehicle. The number of barriers lit up and the blinking frequency will depend on the degree of danger the expert system estimates there is. In short, the light path shows if drivers are behaving suitably or not and tries to make him or her aware of it.
      Graphical abstract image

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.03.008
      Issue No: Vol. 75 (2018)
       
  • Discrete-time distributed Kalman filter design for formations of
           autonomous vehicles
    • Authors: Daniel Viegas; Pedro Batista; Paulo Oliveira; Carlos Silvestre
      Pages: 55 - 68
      Abstract: Publication date: June 2018
      Source:Control Engineering Practice, Volume 75
      Author(s): Daniel Viegas, Pedro Batista, Paulo Oliveira, Carlos Silvestre
      This paper addresses the problem of distributed state estimation in a multi-vehicle framework. Each vehicle aims to estimate its own state relying on locally available measurements and limited communication with other vehicles in the vicinity. The dynamics of the problem are formulated as a discrete-time Kalman filtering problem with a sparsity constraint on the gain, and two different algorithms for computation of steady-state observer gains for arbitrary fixed measurement topologies are introduced. Their application to the practical problem of distributed localization in a formation of Autonomous Underwater Vehicles (AUVs) is detailed, supported by simulation results.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.03.014
      Issue No: Vol. 75 (2018)
       
  • Friction-resilient position control for machine tools—Adaptive and
           sliding-mode methods compared
    • Authors: Dimitrios Papageorgiou; Mogens Blanke; Hans Henrik Niemann; Jan H. Richter
      Pages: 69 - 85
      Abstract: Publication date: June 2018
      Source:Control Engineering Practice, Volume 75
      Author(s): Dimitrios Papageorgiou, Mogens Blanke, Hans Henrik Niemann, Jan H. Richter
      Robust trajectory tracking and increasing demand for high-accuracy tool positioning have motivated research in advanced control design for machine tools. State-of-the-art industry solutions employ cascades of Proportional (P) and Proportional–Integral (PI) controllers for closed-loop servo control of position and velocity of the machine axes. Although these schemes provide the required positioning accuracy in nominal conditions, performance deteriorates with increased friction and wear of the machine. With conventional control, re-tuning is necessary during the lifetime if specified accuracy shall be maintained. This paper investigates whether nonlinear and adaptive controllers can cope with typical levels of friction increase without loss of performance. It evaluates the performance of a state-of-art industry solution with that obtainable with adaptive and sliding mode positioning controls. The main finding is that an adaptive backstepping control is resilient to unknown and increasing friction at realistic levels of wear, where the P-PI control fall short with respect to accuracy. A single-axis test rig with adjustable friction is used to assess the performance of different controllers.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.03.017
      Issue No: Vol. 75 (2018)
       
  • SMR drive performance analysis under different workload environments
    • Authors: Junpeng Niu; Mingzhou Xie; Jun Xu; Lihua Xie; Li Xia
      Pages: 86 - 97
      Abstract: Publication date: June 2018
      Source:Control Engineering Practice, Volume 75
      Author(s): Junpeng Niu, Mingzhou Xie, Jun Xu, Lihua Xie, Li Xia
      As the main stream of Hard Disk Drive (HDD) techniques, Shingled Magnetic Recording (SMR) drives have unique features different from conventional disk drives, e.g., append-only (sequential) write, indirect address mapping and garbage collection. Batch process is also designed to fully utilize the sequential write property to improve the SMR drive performance. The selection of different system parameters and policies affects the system performance and capacity efficiency. However, there is no dedicated analytical tool available so far to guide the parameter and policy selection. A queuing model is built and solved through a Markov chain process for the SMR drive to analyze the system performance under different kinds of system settings and workload environments. the control policies and parameter settings are also studied to explore their relation to the system performance of SMR disks, from the point of views of both analytical model and numerical simulation. An adaptive Garbage Collection (GC) policy is proposed to automatically select the foreground GC and background GC to provide consistent drive performance. A SMR drive simulator is further developed to validate the model and check the performance impacts of different drive parameters. We illustrate the similarity of the analytical and simulation results, and show that our tool can be utilized as the guide of the SMR drive design.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.03.016
      Issue No: Vol. 75 (2018)
       
  • Full-state autopilot-guidance design under a linear quadratic differential
           game formulation
    • Authors: M. Levy; T. Shima; S. Gutman
      Pages: 98 - 107
      Abstract: Publication date: June 2018
      Source:Control Engineering Practice, Volume 75
      Author(s): M. Levy, T. Shima, S. Gutman
      Full-state single-loop and full-state two-loop autopilot-guidance architectures are derived under a linear quadratic differential game formulation. In the full-state single-loop case, the guidance command is injected directly to the actuator, whereas in the full-state two-loop case, it is the input to the autopilot loop. To prevent impractical end-game scenarios, where the states diverge to unacceptable values, a cost function that includes appropriate running cost terms on some of the states is proposed. The conditions for obtaining an equivalence relation between the full-state single-loop and full-state two-loop architectures are derived under a linear quadratic differential game formulation and the proposed cost function. Under such a formulation, the two full-state architectures are identical if and only if the number of guidance commands matches the number of available controllers. The guidance laws performance is illustrated using an interceptor missile having forward and aft controls in linear and nonlinear settings, while considering two types of evasion strategies. The first strategy is a linear controller based on the linear quadratic differential game solution. The second strategy is a “bang–bang” controller based on the optimal evasion solution. It is shown that the linear evasion strategy may not be suitable to represent a realistic evading strategy. In addition, the conditions for the existence of a saddle point solution are analyzed for the two full-state guidance laws.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.03.009
      Issue No: Vol. 75 (2018)
       
  • Adaptive integral terminal sliding mode control for upper-limb
           rehabilitation exoskeleton
    • Authors: A. Riani; T. Madani; A. Benallegue; K. Djouani
      Pages: 108 - 117
      Abstract: Publication date: June 2018
      Source:Control Engineering Practice, Volume 75
      Author(s): A. Riani, T. Madani, A. Benallegue, K. Djouani
      A robust adaptive integral terminal sliding mode control strategy is proposed in this paper to deal with unknown but bounded dynamic uncertainties of a nonlinear system. This method is applied for the control of upper limb exoskeleton in order to achieve passive rehabilitation movements. Indeed, exoskeletons are in direct interaction with the human limb and even if it is possible to identify the nominal dynamics of the exoskeleton, the subject’s limb dynamics remain typically unknown and defer from a person to another. The proposed approach uses only the exoskeleton nominal model while the system upper bounds are adjusted adaptively. No prior knowledge of the exact dynamic model and upper bounds of uncertainties is required. Finite time stability and convergence are proven using Lyapunov theory. Experiments were performed with healthy subjects to evaluate the performance and the efficiency of the proposed controller in tracking trajectories that correspond to passive arm movements.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.02.013
      Issue No: Vol. 75 (2018)
       
  • DC bus voltage stability improvement using disturbance observer
           feedforward control
    • Authors: Jiang You; Mahinda Vilathgamuwa; Negareh Ghasemi
      Pages: 118 - 125
      Abstract: Publication date: June 2018
      Source:Control Engineering Practice, Volume 75
      Author(s): Jiang You, Mahinda Vilathgamuwa, Negareh Ghasemi
      The constant power load (CPL) property of a load converter with tight control results in DC bus voltage oscillations in interconnected power converter systems. In this paper, a disturbance observer (DOB) feedforward compensation scheme is proposed to stabilize the DC bus voltage of a cascaded power converter. An equivalent DC link voltage control model and a disturbance observer are used to reconstruct the dynamic changes of the DC bus current to correct the inner current loop reference of the load converter. Simulation and experimental results show that the proposed method is effective in stabilizing the DC bus voltage.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.03.018
      Issue No: Vol. 75 (2018)
       
  • An incipient fault detection approach via detrending and denoising
    • Authors: Zhangming He; Yuri A.W. Shardt; Dayi Wang; Bowen Hou; Haiyin Zhou; Jiongqi Wang
      Pages: 1 - 12
      Abstract: Publication date: May 2018
      Source:Control Engineering Practice, Volume 74
      Author(s): Zhangming He, Yuri A.W. Shardt, Dayi Wang, Bowen Hou, Haiyin Zhou, Jiongqi Wang
      An incipient fault tends to be buried by either the process trend or the measurement noise. Fault–trend ratio (FTR) and fault–noise ratio (FNR) are two main factors that impact the detection performance. An incipient fault detection approach is proposed in this paper based on the detrending and denoising techniques. There are three main phases in this approach. First, to increase FTR, a detrending algorithm is implemented. The fault detection rate can be significantly enhanced, when the normal trend is eliminated from the testing residual. Second, to increase FNR, a denoising algorithm is realized. The residual obtained from this algorithm can avoid the incipient fault being buried by the widely oscillating noise. Therefore the fault detection performance can be further improved. Third, the new detection statistic is composed based on the two algorithms. The approach is applied to a simulated process, a satellite attitude control system process, and the Tennessee Eastman process. The comparison results show that the proposed method outperforms the traditional Hotelling method in detecting incipient faults.

      PubDate: 2018-02-26T13:43:13Z
      DOI: 10.1016/j.conengprac.2018.02.005
      Issue No: Vol. 74 (2018)
       
  • Active disturbance rejection control applied to automated steering for
           lane keeping in autonomous vehicles
    • Authors: Zhengrong Chu; Yuming Sun; Christine Wu; Nariman Sepehri
      Pages: 13 - 21
      Abstract: Publication date: May 2018
      Source:Control Engineering Practice, Volume 74
      Author(s): Zhengrong Chu, Yuming Sun, Christine Wu, Nariman Sepehri
      The automated steering for lane keeping is an important technique used in the autonomous vehicles. To achieve satisfactory lane keeping performance, the steering control scheme is required to be robust against the vehicle uncertainties and the external disturbances, and be easy to be implemented. To this end, the active disturbance rejection control (ADRC) is applied to the steering controller design in this paper. The ADRC scheme estimates the vehicle uncertainties and the external disturbances in real-time and then compensates them actively. The stability analysis based on the concept of Lyapunov exponents shows that the ADRC control system is exponentially stable around the equilibrium point. Simulations under varying vehicle parameters and disturbances show that the ADRC scheme is able to keep the vehicle within the lane with maximum lateral offset of 0.1 m. Finally, the ADRC scheme is implemented on a scale vehicle. Some necessary electronic devices are installed into the scale vehicle to realize the automated steering. The comparisons between the ADRC scheme and the PID controller show that the scale vehicle controlled by the ADRC scheme performs better with maximum 0.03 m and 0.16 m lateral offsets during the straight and curved lane keeping, respectively. It is also shown that the ADRC scheme is able to perform the lane change. Since the ADRC scheme and the software developed in this paper are independent on a specific platform, they can be implemented on a full-size vehicle.

      PubDate: 2018-02-26T13:43:13Z
      DOI: 10.1016/j.conengprac.2018.02.002
      Issue No: Vol. 74 (2018)
       
  • Automatic regulatory control in type 1 diabetes without carbohydrate
           counting
    • Authors: Patricio Colmegna; Fabricio Garelli; Hernán De Battista; Ricardo Sánchez-Peña
      Pages: 22 - 32
      Abstract: Publication date: May 2018
      Source:Control Engineering Practice, Volume 74
      Author(s): Patricio Colmegna, Fabricio Garelli, Hernán De Battista, Ricardo Sánchez-Peña
      A new approach to automatically regulate the glucose level in type 1 diabetes is presented in this work. This is the so-called Automatic Regulation of Glucose (ARG) algorithm, which is based on a switched Linear Quadratic Gaussian (LQG) inner controller, combined with an outer sliding mode safety loop with Insulin on Board (IOB) constraints. In silico and in vivo results without feedforward insulin boluses delivered at meal times indicate that safe blood glucose control can be achieved by the proposed controller. This controller is simple to migrate to well-known hardware platforms, and intuitive to tune using a priori clinical information.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.02.003
      Issue No: Vol. 74 (2018)
       
  • Energy shaping control for buck–boost converters with unknown
           constant power load
    • Authors: Wei He; Carlos Abraham Soriano-Rangel; Romeo Ortega; Alessandro Astolfi; Fernando Mancilla-David; Shihua Li
      Pages: 33 - 43
      Abstract: Publication date: May 2018
      Source:Control Engineering Practice, Volume 74
      Author(s): Wei He, Carlos Abraham Soriano-Rangel, Romeo Ortega, Alessandro Astolfi, Fernando Mancilla-David, Shihua Li
      We develop in this paper an adaptive passivity-based controller for output voltage regulation of DC–DC buck–boost converter with an unknown constant power load. This control problem is theoretically challenging since the average model of the converter is a bilinear second order system that, due to the presence of the constant power load, is non-minimum phase with respect to both states. A solution to the problem was recently reported in Wei et al. (2017), however, the resulting control law is extremely complicated to be of practical interest. The purpose of this paper is to present a new, significantly simpler, controller that can be easily implemented in applications. The key modifications introduced in the new design are the use of a change of coordinates and a partial linearization that transform the system into a cascade form, to which an adaptive energy-shaping controller is applied. Another advantage of the proposed controller, besides its simplicity, is that it is amenable for the addition of an outer-loop PI that improves its transient and disturbance rejection performances. Simulations and experimental results are provided to assess the improved performance of the proposed controller.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.02.006
      Issue No: Vol. 74 (2018)
       
  • Robust tuning of a first order reduced Active Disturbance Rejection
           Controller
    • Authors: Pawel Nowak; Jacek Czeczot; Tomasz Klopot
      Pages: 44 - 57
      Abstract: Publication date: May 2018
      Source:Control Engineering Practice, Volume 74
      Author(s): Pawel Nowak, Jacek Czeczot, Tomasz Klopot
      In this paper, the robust tuning rules for a first order reduced ADRC (Active Disturbance Rejection Controller) are suggested for lag dominated processes. Based on the D-partition method and FOPDT (First Order plus Dead Time) process approximation, a software tool is designed that allows for tuning subject to phase and gain margins. Based on this software, six robust tuning rules were derived. For these rules, the results of simulation validation in the application to benchmark processes are presented and compared to the performance of PI-based control systems. Additional experimental validation shows the practical applicability of the suggested tuning rules.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.02.001
      Issue No: Vol. 74 (2018)
       
  • Sliding-mode observers for state and disturbance estimation in
           electro-hydraulic systems
    • Authors: Gianluca Palli; Salvatore Strano; Mario Terzo
      Pages: 58 - 70
      Abstract: Publication date: May 2018
      Source:Control Engineering Practice, Volume 74
      Author(s): Gianluca Palli, Salvatore Strano, Mario Terzo
      In this paper, the comparison between a sliding mode observer and a high-order sliding mode observer for hydraulic actuators is presented considering different sets of available measurements, parametric uncertainties and model nonlinearities. The friction acting on the hydraulic cylinder and a dead-zone in the valve have been taken into account as uncertain disturbances acting on the system. For comparison purposes, the observation results are set side by side with the ones provided by an extended Kalman filter. Several simulations have been conducted in order to analyze the performance of the estimators, particularly with respect to the possibility of estimating the disturbances and unknown dynamics acting on the system, also in presence of measurement noise. Finally, experimental results are presented to validate the effectiveness of the proposed observers in real conditions.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.02.007
      Issue No: Vol. 74 (2018)
       
  • A comparative assessment of hierarchical control structures for
           spatiotemporally-varying systems, with application to airborne wind energy
           
    • Authors: Alireza Bafandeh; Shamir Bin-Karim; Ali Baheri; Christopher Vermillion
      Pages: 71 - 83
      Abstract: Publication date: May 2018
      Source:Control Engineering Practice, Volume 74
      Author(s): Alireza Bafandeh, Shamir Bin-Karim, Ali Baheri, Christopher Vermillion
      Optimal control in a spatiotemporally varying environment is difficult, especially if the environment is partially observable. Altitude optimization of an airborne wind energy (AWE) system, in which the tower and foundation of a contemporary wind turbine is replaced by tethers and a lifting body, is a challenging problem of this kind. The wind velocity changes both spatially and temporally, and it can only be measured at the altitude where the system is flying, making the problem partially observable. In this work, we propose and evaluate hierarchical structures for the aforementioned problem, which fuse coarse, global for the chosen grid resolution and prediction horizon, where applicable control with fine, local control. These controllers leverage the advantages of both fine, local and coarse, global control schemes, while addressing their limitations. We show through simulation, using the real wind velocity data, that the hierarchical structures outperform legacy control strategies in terms of net energy generation.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.02.008
      Issue No: Vol. 74 (2018)
       
  • A hidden-Gamma model-based filtering and prediction approach for monotonic
           health factors in manufacturing
    • Authors: Gian Antonio Susto; Andrea Schirru; Simone Pampuri; Alessandro Beghi; Giuseppe De Nicolao
      Pages: 84 - 94
      Abstract: Publication date: May 2018
      Source:Control Engineering Practice, Volume 74
      Author(s): Gian Antonio Susto, Andrea Schirru, Simone Pampuri, Alessandro Beghi, Giuseppe De Nicolao
      In the context of Smart Monitoring and Fault Detection and Isolation in industrial systems, the aim of Predictive Maintenance technologies is to predict the happening of process or equipment faults. In order for a Predictive Maintenance technology to be effective, its predictions have to be both accurate and timely for taking strategic decisions on maintenance scheduling, in a cost-minimization perspective. A number of Predictive Maintenance technologies are based on the use of “health factors”, quantitative indicators associated with the equipment wear that exhibit a monotone evolution. In real industrial environment, such indicators are usually affected by measurement noise and non-uniform sampling time. In this work we present a methodology, formulated as a stochastic filtering problem, to optimally predict the evolution of the aforementioned health factors based on noisy and irregularly sampled observations. In particular, a hidden Gamma process model is proposed to capture the nonnegativity and nonnegativity of the derivative of the health factor. As such filtering problem is not amenable to a closed form solution, a numerical Monte Carlo approach based on particle filtering is here employed. An adaptive parameter identification procedure is proposed to achieve the best trade-off between promptness and low noise sensitivity. Furthermore, a methodology to identify the risk function associated to the observed equipment based on previous maintenance data is proposed. The present study is motivated and tested on a real industrial Predictive Maintenance problem in semiconductor manufacturing, with reference to a dry etching equipment.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.02.011
      Issue No: Vol. 74 (2018)
       
  • Reaction zone monitoring in biomass combustion
    • Authors: Attila Garami; Bernadett Csordás; Árpád Palotás; Pál Tóth
      Pages: 95 - 106
      Abstract: Publication date: May 2018
      Source:Control Engineering Practice, Volume 74
      Author(s): Attila Garami, Bernadett Csordás, Árpád Palotás, Pál Tóth
      In this work we demonstrate the utilization of a machine vision-based combustion monitoring system in biomass combustion. The proposed system monitored the location of the reaction zone in a 3 MW, grate-fired biomass boiler operated at varying loads and with fluctuating fuel quality. The system can help guarantee equal primary air supply to different regions of the grate and avoid the elutriation of fly ash by providing information on the location of the reaction zone. Strong correlation was found between the reaction zone boundary location and most process parameters, indicating that the location of the reaction zone can be a useful metric in monitoring and control by providing supplementary measurements to already existing monitoring to avoid over-emissions and improve economics.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.02.009
      Issue No: Vol. 74 (2018)
       
  • An improved instrumental variable method for industrial robot model
           identification
    • Authors: M. Brunot; A. Janot; P.C. Young; F. Carrillo
      Pages: 107 - 117
      Abstract: Publication date: May 2018
      Source:Control Engineering Practice, Volume 74
      Author(s): M. Brunot, A. Janot, P.C. Young, F. Carrillo
      Industrial robots are electro-mechanical systems with double integrator behaviour, necessitating operation and model identification under closed-loop control conditions. The Inverse Dynamic Identification Model (IDIM) is a mechanical model based on Newton’s laws that has the advantage of being linear with respect to the parameters. Existing Instrumental Variable (IDIM-IV) estimation provides a robust solution to this estimation problem and the paper introduces an improved IDIM-PIV method that takes account of the additive noise characteristics by adding prefilters that provide lower variance estimates of the IDIM parameters. Inspired by the prefiltering approach used in optimal Refined Instrumental Variable (RIV) estimation, the IDIM-PIV method identifies the nonlinear physical model of the robot, as well as the noise model resulting from the feedback control system. It also has the advantage of providing a systematic prefiltering process, in contrast to that required for the previous IDIM-IV method. The issue of an unknown controller is also considered and resolved using existing parametric identification. The evaluation of the new estimation algorithms on a six degrees-of-freedom rigid robot shows that they improve statistical efficiency, with the controller either known or identified as an intrinsic part of the IDIM-PIV algorithm.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.02.010
      Issue No: Vol. 74 (2018)
       
  • Cooperative coverage path planning for visual inspection
    • Authors: Sina Sharif Mansouri; Christoforos Kanellakis; Emil Fresk; Dariusz Kominiak; George Nikolakopoulos
      Pages: 118 - 131
      Abstract: Publication date: May 2018
      Source:Control Engineering Practice, Volume 74
      Author(s): Sina Sharif Mansouri, Christoforos Kanellakis, Emil Fresk, Dariusz Kominiak, George Nikolakopoulos
      This article addresses the inspection problem of a complex 3D infrastructure using multiple Unmanned Aerial Vehicles (UAVs). The main novelty of the proposed scheme stems from the establishment of a theoretical framework capable of providing a path for accomplishing a full coverage of the infrastructure, without any further simplifications (number of considered representation points), by slicing it by horizontal planes to identify branches and assign specific areas to each agent as a solution to an overall optimization problem. Furthermore, the image streams collected during the coverage task are post-processed using Structure from Motion, stereo SLAM and mesh reconstruction algorithms, while the resulting 3D mesh can be used for further visual inspection purposes. The performance of the proposed Collaborative-Coverage Path Planning (C-CPP) has been experimentally evaluated in multiple indoor and realistic outdoor infrastructure inspection experiments and as such it is also contributing significantly towards real life applications for UAVs.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.03.002
      Issue No: Vol. 74 (2018)
       
  • Distributed wide-area control of power system oscillations under
           communication and actuation constraints
    • Authors: Abhishek Jain; Aranya Chakrabortty; Emrah Biyik
      Pages: 132 - 143
      Abstract: Publication date: May 2018
      Source:Control Engineering Practice, Volume 74
      Author(s): Abhishek Jain, Aranya Chakrabortty, Emrah Biyik
      In this paper a distributed Model Predictive Control design is presented for inter-area oscillation damping in power systems under two critical cyber–physical constraints — namely, communication constraints that lead to sparsification of the underlying communication network, and actuation constraints that respect the saturation limits of generator controllers. In the current state-of-art, distributed controllers in power systems are executed over fixed communication topologies that are most often agnostic of the magnitude and location of the incoming disturbance signals. This often leads to a sub-optimal closed-loop performance. In contrast, the communication topology for the proposed controller is selected in real-time after a disturbance event based on event-specific correlations of the generator states with the dominant oscillation modes that are excited by that event. Since these correlations can differ from one event to another, so can the choice of the communication topology. These correlations are used to identify the most important sets of generators that must exchange state information for enhancing closed-loop damping of the inter-area modal frequencies. Effectiveness of this strategy is shown via simulations on the 48-machine, 140-bus model for the Northeast Power Coordinating Council.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.03.003
      Issue No: Vol. 74 (2018)
       
  • Quantum statistic based semi-supervised learning approach for industrial
           soft sensor development
    • Authors: Jinlin Zhu; Zhiqiang Ge; Zhihuan Song
      Pages: 144 - 152
      Abstract: Publication date: May 2018
      Source:Control Engineering Practice, Volume 74
      Author(s): Jinlin Zhu, Zhiqiang Ge, Zhihuan Song
      Unlike process variables which can be easily measured online, quality variables are often hard to be collected. Therefore, only a small proportion of soft sensor inputs are attached with quality related output labels. The semi-supervised learning mechanism can elegantly incorporate unlabeled input samples for soft sensor improvement and hence has become popular. In this work, a novel mechanism called quantum statistic is incorporated with semi-supervised learning by quantum states. The quantum states are constructed by superposing conventional pure states with composite states and the extended state space as the complements could be more desirable for representing state uncertainties of incomplete labels. Based on that, a quantum statistical based semi-supervised soft sensor is developed. The quantum statistic based model is comprehensively compared with the conventional state-of-the-art method in a numerical example and an industrial process. Results demonstrate that the proposed soft sensor is more effective and stable than the traditional state-of-art method.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.03.001
      Issue No: Vol. 74 (2018)
       
  • Fully automatic visual servoing control for work-class marine intervention
           ROVs
    • Authors: Satja Sivčev; Matija Rossi; Joseph Coleman; Gerard Dooly; Edin Omerdić; Daniel Toal
      Pages: 153 - 167
      Abstract: Publication date: May 2018
      Source:Control Engineering Practice, Volume 74
      Author(s): Satja Sivčev, Matija Rossi, Joseph Coleman, Gerard Dooly, Edin Omerdić, Daniel Toal
      ROVs with hydraulic manipulators are extensively used for subsea intervention. With camera feedback from the scene, manipulators are teleoperated and slaved to pilot held master arms. While standard for offshore oil and gas, for challenging applications in waves or currents a new approach is required. We present development of robot arm visual servo control approaches used in manufacturing and the transfer and adaption of these to underwater hydraulic manipulators. This is the first time a visual servoing algorithm for automated manipulation has been developed and verified, through subsea trials, on a commercial work-class ROV with industry standard hydraulic manipulators.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.03.005
      Issue No: Vol. 74 (2018)
       
  • Improving low cost sensor based vehicle positioning with Machine Learning
    • Authors: Ikram Belhajem; Yann Ben Maissa; Ahmed Tamtaoui
      Pages: 168 - 176
      Abstract: Publication date: May 2018
      Source:Control Engineering Practice, Volume 74
      Author(s): Ikram Belhajem, Yann Ben Maissa, Ahmed Tamtaoui
      Current fleet management solutions rely on real time vehicle information to efficiently resolve transportation problems. In this study, a novel robust approach based on combining the Extended Kalman Filter (EKF) with Machine Learning techniques, Neural Networks or Support Vector Machines, is introduced to improve the accuracy of vehicle position estimation and circumvent the EKF limitations. The proposed solution guarantees also a low cost by using the Global Positioning System enhanced with Dead Reckoning integrated sensors. To verify our approach, extensive simulation tests are conducted on field data sets and very promising progress is obtained in the estimated vehicle position.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.03.006
      Issue No: Vol. 74 (2018)
       
  • Assistive-compliant control of wearable robots for partially disabled
           individuals
    • Authors: Ali Taherifar; Gholamreza Vossoughi; Ali Selk Ghafari
      Pages: 177 - 190
      Abstract: Publication date: May 2018
      Source:Control Engineering Practice, Volume 74
      Author(s): Ali Taherifar, Gholamreza Vossoughi, Ali Selk Ghafari
      The main objective of this research was to introduce a smart assist-as-needed control system that helps elderly or partially paralyzed individuals. To ensure that a smart and compliant controller, in each cycle of the gait is developed, we adapted the target impedance gains and feed-forward force of the assistive mechanism according to a learning law. A strength metric was defined to determine when the human needs assistance. Then, a cost function was introduced and the gains are modified to reduce the cost function. Applying the proposed controller, the interaction force between patient’s limb and robot was reduced in cases wherein user has sufficient strength for task execution and minimizes the position error in the sub phases where users need assistance. Using the Lyapunov stability theorem, the stability of the closed loop system was proved without and with parameter uncertainty, respectively. The results of simulations and an experiment on an exoskeleton showed that the proposed adaptive impedance control improves performance to a level substantially higher than that achieved with constant impedance control.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.02.004
      Issue No: Vol. 74 (2018)
       
  • Constrained trajectory planning and actuator design for electromagnetic
           heating systems
    • Authors: Sönke Rhein; Knut Graichen
      Pages: 191 - 203
      Abstract: Publication date: May 2018
      Source:Control Engineering Practice, Volume 74
      Author(s): Sönke Rhein, Knut Graichen
      A trajectory planning approach for electromagnetic heating systems is presented capable to optimize the electrical excitation and spatial configuration of the corresponding actuator (e. g. inductor or electrode). In order to accurately incorporate the electromagnetic and thermal phenomena, a PDE constrained optimization problem is formulated. The optimality conditions are derived in the function space of the original problem formulation following a first optimize then discretize approach to ensure that not only the system dynamics but rather the whole optimality system can be solved by FEM-based simulation software. The major advantage lies in coping with different types of electromagnetic heating systems. Numerical results illustrate the applicability and accuracy of the trajectory planning.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.02.012
      Issue No: Vol. 74 (2018)
       
  • Autonomous vehicle control using a kinematic Lyapunov-based technique with
           LQR-LMI tuning
    • Authors: Eugenio Alcala; Vicenç Puig; Joseba Quevedo; Teresa Escobet; Ramon Comasolivas
      Pages: 1 - 12
      Abstract: Publication date: April 2018
      Source:Control Engineering Practice, Volume 73
      Author(s): Eugenio Alcala, Vicenç Puig, Joseba Quevedo, Teresa Escobet, Ramon Comasolivas
      This work proposes the control of an autonomous vehicle using a Lyapunov-based technique with a LQR-LMI tuning. Using the kinematic model of the vehicle, a non-linear control strategy based on Lyapunov theory is proposed for solving the control problem of autonomous guidance. To optimally adjust the parameters of the Lyapunov controller, the closed loop system is reformulated in a linear parameter varying (LPV) form. Then, an optimization algorithm that solves the LQR-LMI problem is used to determine the controller parameters. Furthermore, the tuning process is complemented by adding a pole placement constraint that guarantees that the maximum achievable performance of the kinematic loop could be achieved by the dynamic loop. The obtained controller jointly with a trajectory generation module are in charge of the autonomous vehicle guidance. Finally, the paper illustrates the performance of the autonomous guidance system in a virtual reality environment (SYNTHIA) and in a real scenario achieving the proposed goal: to move autonomously from a starting point to a final point in a comfortable way.

      PubDate: 2018-01-10T08:21:59Z
      DOI: 10.1016/j.conengprac.2017.12.004
      Issue No: Vol. 73 (2018)
       
  • Incremental model based online dual heuristic programming for nonlinear
           adaptive control
    • Authors: Ye Zhou; Erik-Jan van Kampen; Qi Ping Chu
      Pages: 13 - 25
      Abstract: Publication date: April 2018
      Source:Control Engineering Practice, Volume 73
      Author(s): Ye Zhou, Erik-Jan van Kampen, Qi Ping Chu
      Dual heuristic programming has gained an increasing interest in recent years because it provides an effective process for optimal adaptive control of uncertain nonlinear systems. However, it requires an off-line stage to train a global system model from a representative model, which is often infeasible to obtain in practice. This paper presents a new and efficient approach for online self-learning control based on dual heuristic programming. This method uses a recursive least square method to online identify an incremental model of the system instead of a global system model. The presented incremental model based dual heuristic programming method can adaptively generate a near-optimal controller online without a priori information of the system dynamics or an off-line training stage. To compare the online adaptability of the conventional dual heuristic programming method and the newly proposed method, two numerical experiments are performed: an online reference tracking task and a fault-tolerant control task. The results reveal that the proposed method outperforms the conventional dual heuristic programming method in online learning capacity, efficiency, accuracy, and robustness.

      PubDate: 2018-02-26T13:43:13Z
      DOI: 10.1016/j.conengprac.2017.12.011
      Issue No: Vol. 73 (2018)
       
  • Nonlinear position and stiffness Backstepping controller for a two Degrees
           of Freedom pneumatic robot
    • Authors: Nicolas Herzig; Richard Moreau; Tanneguy Redarce; Frédéric Abry; Xavier Brun
      Pages: 26 - 39
      Abstract: Publication date: April 2018
      Source:Control Engineering Practice, Volume 73
      Author(s): Nicolas Herzig, Richard Moreau, Tanneguy Redarce, Frédéric Abry, Xavier Brun
      This paper presents an architecture of a 2 Degrees of Freedom pneumatic robot which can be used as a haptic interface. To improve the haptic rendering of this device, a nonlinear position and stiffness controller without force measurement based on a Backstepping synthesis is presented. Thus, the robot can follow a targeted trajectory in Cartesian position with a variable compliant behavior when disturbance forces are applied. An appropriate tuning methodology of the closed-loop stiffness and closed-loop damping of the robot is given to obtain a desired disturbance response. The models, the synthesis and the stability analysis of this controller are described in this paper. Two models are presented in this paper, the first one is an accurate simulation model which describes the mechanical behavior of the robot, the thermodynamics phenomena in the pneumatic actuators, and the servovalves characteristics. The second model is the model used to synthesize the controller. This control model is obtained by simplifying the simulation model to obtain a MIMO strict feedback form. Finally, some simulation and experimental results are given and the controller performances are discussed and compared with a classical linear impedance controller.

      PubDate: 2018-02-26T13:43:13Z
      DOI: 10.1016/j.conengprac.2017.12.007
      Issue No: Vol. 73 (2018)
       
  • Hierarchical nonlinear optimization-based controller of a continuous strip
           annealing furnace
    • Authors: S. Strommer; M. Niederer; A. Steinboeck; A. Kugi
      Pages: 40 - 55
      Abstract: Publication date: April 2018
      Source:Control Engineering Practice, Volume 73
      Author(s): S. Strommer, M. Niederer, A. Steinboeck, A. Kugi
      Continuous strip annealing furnaces are complex multi-input multi-output nonlinear distributed-parameter systems. They are used in industry for heat treatment of steel strips. The product portfolio and different materials to be heat-treated is steadily increasing and the demands on high throughput, minimum energy consumption, and minimum waste have gained importance over the last years. Designing a furnace control concept that ensures accurate temperature tracking under consideration of all input and state constraints in transient operations is a challenging task, in particular in view of the large thermal inertia of the furnace compared to the strip. The control problem at hand becomes even more complicated because the burners in the different heating zones of the considered furnace can be individually switched on and off. In this paper, a real-time capable optimization-based hierarchical control concept is developed, which consists of a static optimization for the selection of an operating point for each strip, a trajectory generator for the strip velocity, a dynamic optimization routine using a long prediction horizon to plan reference trajectories for the strip temperature as well as switching times for heating zones, and a nonlinear model predictive controller with a short prediction horizon for temperature tracking. The mass flows of fuel and the strip velocity are the basic control inputs. The underlying optimization problems are transformed to unconstrained problems and solved by the Gauss–Newton method. The performance of the proposed control concept is demonstrated by an experimentally validated simulation model of a continuous strip annealing furnace at voestalpine Stahl GmbH, Linz, Austria.
      Graphical abstract image

      PubDate: 2018-02-26T13:43:13Z
      DOI: 10.1016/j.conengprac.2017.12.005
      Issue No: Vol. 73 (2018)
       
  • Accuracy–simplicity trade-off for small-scale helicopter models: A
           comparative study based on flight data
    • Authors: Emmanuel Roussel; Vincent Gassmann; Edouard Laroche
      Pages: 56 - 65
      Abstract: Publication date: April 2018
      Source:Control Engineering Practice, Volume 73
      Author(s): Emmanuel Roussel, Vincent Gassmann, Edouard Laroche
      A good model is a trade-off between simplicity of the model structure and accuracy of the prediction. Higher accuracy is generally expected from more complex models, but at the cost of higher computational burden, more complex handling and potential identifiability issues. Depending on the targeted use, assumptions and simplifications are made to find the simplest model still capturing the important phenomena. These choices are not straightforward and, to this end, the paper gives a comparison of miniature helicopter models often found in the literature. The contribution of the paper is thus twofold. A time-domain identification procedure for parametric models of miniature helicopters is first described and applied to four different models with increasing complexity. The procedure is based on flight data obtained during a manual slow-speed flight. Secondly, the accuracies of these models are evaluated and compared, which highlights the main differences and improvements brought by the differences in the aerodynamic model equations and allows the selection of a relevant model structure depending on the target application.

      PubDate: 2018-02-26T13:43:13Z
      DOI: 10.1016/j.conengprac.2018.01.001
      Issue No: Vol. 73 (2018)
       
  • Cooperative energy management of electrified vehicles on hilly roads
    • Authors: Mattias Hovgard; Oscar Jonsson; Nikolce Murgovski; Martin Sanfridson; Jonas Fredriksson
      Pages: 66 - 78
      Abstract: Publication date: April 2018
      Source:Control Engineering Practice, Volume 73
      Author(s): Mattias Hovgard, Oscar Jonsson, Nikolce Murgovski, Martin Sanfridson, Jonas Fredriksson
      This paper presents a control strategy and an assessment study for the potential of minimizing fuel consumption of electrified and/or conventional vehicles driving in a hilly terrain. The main idea is to minimize the amount of energy wasted on air resistance and mechanical braking. The former is achieved by having the vehicles drive close to each other. The latter is achieved by either allowing the speed to vary and thereby reduce braking, or by using the electric machine to brake and convert kinetic energy to electric energy that is stored in the battery. We propose a control strategy that is separated into two control layers. One layer optimizes vehicle velocity and battery state of charge using convex optimization, and the other optimizes gear and engine on/off state trajectories using dynamic programming. The control strategy is then applied to several test cases, in order to evaluate the reduction in fuel consumption due to platooning, optimal battery usage and optimal velocity control in a hilly terrain.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2017.12.010
      Issue No: Vol. 73 (2018)
       
  • Cascaded incremental nonlinear dynamic inversion for MAV disturbance
           rejection
    • Authors: E.J.J. Smeur; G.C.H.E. de Croon; Q. Chu
      Pages: 79 - 90
      Abstract: Publication date: April 2018
      Source:Control Engineering Practice, Volume 73
      Author(s): E.J.J. Smeur, G.C.H.E. de Croon, Q. Chu
      This paper presents the cascaded integration of Incremental Nonlinear Dynamic Inversion (INDI) for attitude control and INDI for position control of micro air vehicles. Significant improvements over a traditional Proportional Integral Derivative (PID) controller are demonstrated in an experiment where the quadrotor flies in and out of a 10 m/s windtunnel exhaust. The control method does not rely on frequent position updates, as is demonstrated in an outside experiment using a standard GPS module. Finally, we investigate the effect of using a linearization to calculate thrust vector increments, compared to a nonlinear calculation.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.01.003
      Issue No: Vol. 73 (2018)
       
  • Extended Kalman filter for fouling detection in thermal power plant
           reheater
    • Authors: Anitha Kumari Sivathanu; Srinivasan Subramanian
      Pages: 91 - 99
      Abstract: Publication date: April 2018
      Source:Control Engineering Practice, Volume 73
      Author(s): Anitha Kumari Sivathanu, Srinivasan Subramanian
      A model based on-line foul monitoring approach for a power plant reheater is proposed. Dual Extended Kalman Filter (DEKF) is designed to estimate the model parameters that influence fouling. Based on the estimated parameters the performance index (Cleanliness Factor) is obtained to retrieve the extent of fouling on reheater. The simulation and experimental validation using power plant data shows the efficacy of DEKF over conventional Joint-EKF (JEKF) in estimating the model parameters. The outcome of the work will assist in soot blow scheduling for reheater by perceiving the fall in cleanliness factor and will also help in analysing its impact on heat transfer efficiency.

      PubDate: 2018-02-26T13:43:13Z
      DOI: 10.1016/j.conengprac.2018.01.005
      Issue No: Vol. 73 (2018)
       
  • Digital state-feedback control of an interleaved DC–DC boost converter
           with bifurcation analysis
    • Authors: G. Gkizas; C. Yfoulis; C. Amanatidis; F. Stergiopoulos; D. Giaouris; C. Ziogou; S. Voutetakis; S. Papadopoulou
      Pages: 100 - 111
      Abstract: Publication date: April 2018
      Source:Control Engineering Practice, Volume 73
      Author(s): G. Gkizas, C. Yfoulis, C. Amanatidis, F. Stergiopoulos, D. Giaouris, C. Ziogou, S. Voutetakis, S. Papadopoulou
      This paper evaluates several state-feedback control design methods for a multi-phase interleaved DC–DC boost converter with an arbitrary number of legs. The advantages of state-feedback control laws are numerous since they do not burden the system with the introduction of further zeros or poles that may lead to poorer performance as far as overshoot and disturbance rejection is concerned. Both static and dynamic full state-feedback control laws are designed based on the converter’s averaged model. Building on previous work, this paper introduces significant extensions on the investigation of several undesirable bifurcation phenomena. In the case of static state-feedback it is shown that interleaving can give rise to more severe bifurcation phenomena, as the number of phases is increased, leading to multiple equilibria. As a remedy, a bifurcation analysis procedure is proposed that can predict the generation of multiple equilibria. The novelty of this paper is that this analysis can be integrated into the control design so that multiple equilibria can be completely avoided or ruled out of the operating region of interest. The proposed control laws are digitally implemented and validated in a 2-leg case study using both simulation and experimentation.

      PubDate: 2018-02-26T13:43:13Z
      DOI: 10.1016/j.conengprac.2018.01.004
      Issue No: Vol. 73 (2018)
       
  • Experimental validation of attitude and rate-sensor bias filter using
           range-difference measurements
    • Authors: Erlend K. Jørgensen; Thor I. Fossen; Ingrid Schjølberg; Paulo T.T. Esperança
      Pages: 112 - 123
      Abstract: Publication date: April 2018
      Source:Control Engineering Practice, Volume 73
      Author(s): Erlend K. Jørgensen, Thor I. Fossen, Ingrid Schjølberg, Paulo T.T. Esperança
      This paper considers the problem of constructing a filter for estimating attitude and rate-sensor bias, that has both proven stability and close-to-optimal performance with respect to noise. The filter is based on measuring the difference in time of arrival for signals sent from three or more known, fixed positions to two or more receivers on the vehicle. An inertial measurement unit is also used, both rate-sensor and accelerometer measurements, and a position estimate is needed, generated from depth and time of arrival measurements. The vectors between receivers on the vehicle are assumed to be known in the body frame, and are calculated in the inertial frame through an algebraic transformation. These vectors are used as input for a non-linear observer along with rate-sensor and accelerometer data, estimating Euler angles and rate-sensor bias. These estimates are used as a linearization point for a Linearized Kalman Filter, taking the full non-linear system into account. Two experiments are run, and the filter is compared to an Extended Kalman Filter, and a non-implementable Linearized Kalman Filter using the true state as linearization point.

      PubDate: 2018-02-26T13:43:13Z
      DOI: 10.1016/j.conengprac.2018.01.002
      Issue No: Vol. 73 (2018)
       
  • An experimental comparison of PID autotuners
    • Authors: Josefin Berner; Kristian Soltesz; Tore Hägglund; Karl Johan Åström
      Pages: 124 - 133
      Abstract: Publication date: April 2018
      Source:Control Engineering Practice, Volume 73
      Author(s): Josefin Berner, Kristian Soltesz, Tore Hägglund, Karl Johan Åström
      In this paper two novel autotuners are compared with two industrially available ones. The aim is to see if the research frontline can improve the industry standard of today. Experiments are made on three laboratory processes with different characteristics. Two lag-dominated processes of which one is a level control problem with fast dynamics, and one a temperature control problem with slow dynamics, as well as one delay-dominated level control process. Both the experiments and the obtained controller performances are evaluated and discussed. The results show that the performance of the state-of-the-art industrial autotuners can be significantly improved.

      PubDate: 2018-02-26T13:43:13Z
      DOI: 10.1016/j.conengprac.2018.01.006
      Issue No: Vol. 73 (2018)
       
  • Model-free fault detection and isolation of a benchmark process control
           system based on multiple classifiers techniques—A comparative study
    • Authors: Hasan Abbasi Nozari; Sina Nazeri; Hamed Dehghan Banadaki; Paolo Castaldi
      Pages: 134 - 148
      Abstract: Publication date: April 2018
      Source:Control Engineering Practice, Volume 73
      Author(s): Hasan Abbasi Nozari, Sina Nazeri, Hamed Dehghan Banadaki, Paolo Castaldi
      This paper presents a combined data-driven framework for fault detection and isolation (FDI) based on the ensemble of diverse classification schemes. The proposed FDI scheme is configured in series and parallel forms in the sense that in series form the decision on the occurrence of fault is made in FD module, and subsequently, the FI module coupled to the FD module will be activated for fault indication purposes. On the other hand, in parallel form a single module is employed for FDI purposes, simultaneously. In other words, two separate multiple-classifiers schemes are presented by using fourteen various statistical and non-statistical classification schemes. Furthermore, in this study, a novel ensemble classification scheme namely blended learning (BL) is proposed for the first time where single and boosted classifiers are blended as the local classifiers in order to enrich the classification performance. Single-classifier schemes are also exploited in FDI modules along with the ensemble-classifier methods for comparison purposes. In order to show the performance of proposed FDI method, it was also tested and validated on DAMADICS actuator system benchmark. Besides, comparative study with the related works done on this benchmark is provided to show the pros and cons of the proposed FDI method.

      PubDate: 2018-02-26T13:43:13Z
      DOI: 10.1016/j.conengprac.2018.01.007
      Issue No: Vol. 73 (2018)
       
  • Control-oriented physiological modeling of hemodynamic responses to blood
           volume perturbation
    • Authors: Ramin Bighamian; Bahram Parvinian; Christopher G. Scully; George Kramer; Jin-Oh Hahn
      Pages: 149 - 160
      Abstract: Publication date: April 2018
      Source:Control Engineering Practice, Volume 73
      Author(s): Ramin Bighamian, Bahram Parvinian, Christopher G. Scully, George Kramer, Jin-Oh Hahn
      This paper presents a physiological model to reproduce hemodynamic responses to blood volume perturbation. The model consists of three sub-models: a control-theoretic model relating blood volume response to blood volume perturbation; a simple physics-based model relating blood volume to stroke volume and cardiac output; and a phenomenological model relating cardiac output to blood pressure. A unique characteristic of this model is its balance for simplicity and physiological transparency. Initial validity of the model was examined using experimental data collected from 11 animals. The model may serve as a viable basis for the design and evaluation of closed-loop fluid resuscitation controllers.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.01.008
      Issue No: Vol. 73 (2018)
       
  • Sliding mode voltage control of boost converters in DC microgrids
    • Authors: Michele Cucuzzella; Riccardo Lazzari; Sebastian Trip; Simone Rosti; Carlo Sandroni; Antonella Ferrara
      Pages: 161 - 170
      Abstract: Publication date: April 2018
      Source:Control Engineering Practice, Volume 73
      Author(s): Michele Cucuzzella, Riccardo Lazzari, Sebastian Trip, Simone Rosti, Carlo Sandroni, Antonella Ferrara
      This paper deals with the design of a robust decentralized control scheme for voltage regulation in boost-based DC microgrids. The proposed solution consists of the design of a suitable manifold on which voltage regulation is achieved even in presence of unknown load demand and modeling uncertainties. A second order sliding mode control is used to constrain the state of the microgrid to this manifold by generating continuous control inputs that can be used as duty cycles of the power converters. The proposed control scheme has been theoretically analyzed and validated through experiments on a real DC microgrid.

      PubDate: 2018-02-26T13:43:13Z
      DOI: 10.1016/j.conengprac.2018.01.009
      Issue No: Vol. 73 (2018)
       
  • Increasing system test coverage in production automation systems
    • Authors: Sebastian Ulewicz; Birgit Vogel-Heuser
      Pages: 171 - 185
      Abstract: Publication date: April 2018
      Source:Control Engineering Practice, Volume 73
      Author(s): Sebastian Ulewicz, Birgit Vogel-Heuser
      An approach is introduced, which supports a testing technician in the identification of possibly untested behavior of control software of fully integrated automated production systems (aPS). Based on an approach for guided semi-automatic system testing, execution traces are recorded during testing, allowing for a subsequent coverage assessment. As the behavior of an aPS is highly dependent on the software, omitted system behavior can be identified and assessed for criticality. Through close cooperation with industry, this approach represents the first coverage assessment approach for system testing in production automation to be applied on real industrial objects and evaluated by industrial experts.

      PubDate: 2018-04-15T14:39:41Z
      DOI: 10.1016/j.conengprac.2018.01.010
      Issue No: Vol. 73 (2018)
       
  • Finite control set model predictive control scheme of four-switch
           three-phase rectifier with load current observer
    • Authors: Lisi Tian; Jin Zhao; Dehong Zhou
      Pages: 186 - 194
      Abstract: Publication date: April 2018
      Source:Control Engineering Practice, Volume 73
      Author(s): Lisi Tian, Jin Zhao, Dehong Zhou
      Three-phase rectifier is typically realized by six power switches. However, this rectifier is fault sensitive in power switches. To enable continued controllable operation, the grid phase with fault rectifier leg can be connected to center tap of the dc-link capacitors, known as the four-switch three-phase rectifier (FSTPR), using hardware reconfiguration. However, the symmetry of three-phase currents and reliable operation of the FSTPR cannot be retained due to the offset of the two-capacitor voltages. This paper proposes a finite control set model predictive control (FCS-MPC) to obtain the balanced three-phase current with the offset of two-capacitor voltages suppressed. The PI-Controller-free FCS-MPC with a second-order Luenberger observer is adopted to improve the dynamic performance of FSTPR. The performance of the proposed control scheme is illustrated by extensive simulation and experimental results. The comparison with the conventional voltage-oriented-control, which is based on PI controller and pulse width modulation (PWM), is also presented to show the superiority of the proposed FCS-MPC.

      PubDate: 2018-02-26T13:43:13Z
      DOI: 10.1016/j.conengprac.2017.12.009
      Issue No: Vol. 73 (2018)
       
  • Model-based multi-component adaptive prognosis for hybrid dynamical
           systems
    • Authors: Om Prakash; Arun Kumar Samantaray; Ranjan Bhattacharyya
      Pages: 1 - 18
      Abstract: Publication date: March 2018
      Source:Control Engineering Practice, Volume 72
      Author(s): Om Prakash, Arun Kumar Samantaray, Ranjan Bhattacharyya
      A bond graph model-based prognosis method for multiple components with unknown degradation patterns in a hybrid dynamical system is proposed. The traditional approach for remaining useful life prediction with single degradation model is inappropriate for hybrid systems where the dynamics changes according to operating mode. Therefore, multiple degradation models are suggested and these are adapted with new information of the degradation states of the monitored system. Sensitivity-based dynamic signature matrix is utilized for degradation hypothesis generation which provides the deviation directions of fewer hypothesized degradation parameters and thereby accelerates parameter and degradation trend estimation. The results are supported by experiments.

      PubDate: 2017-12-13T02:45:14Z
      DOI: 10.1016/j.conengprac.2017.11.003
      Issue No: Vol. 72 (2017)
       
  • Adaptive soft sensors for quality prediction under the framework of
           Bayesian network
    • Authors: Ziwei Liu; Zhiqiang Ge; Guangjie Chen; Zhihuan Song
      Pages: 19 - 28
      Abstract: Publication date: March 2018
      Source:Control Engineering Practice, Volume 72
      Author(s): Ziwei Liu, Zhiqiang Ge, Guangjie Chen, Zhihuan Song
      Soft sensor is widely used to predict quality-relevant variables which are usually hard to measure timely. Due to model degradation, it is necessary to construct an adaptive model to follow changes of the process. Adaptive models—moving windows (MW), time difference (TD), and locally weighted regression (LWR) under the framework of Bayesian network (BN) are proposed in this paper. BN shows great superiorities over other traditional methods, especially in dealing with missing data and the ability of learning causality. Furthermore, the acquisition of variances in BN makes it possible to perform fault detection, on the basis of 3-sigma criterion. A debutanizer column and CO2 absorption column are provided as two industrial examples to validate the effectiveness of our proposed techniques. In a debutanizer column, RMSE of MW-BN is decreased by 40% in comparison to MW-PLS. In a CO2 absorption column, the largest absolute prediction error of TD-BN is reduced by approximate 7% when compared with that of TD-PLS. Furthermore, about 38% improvements of prediction precision can be achieved in LW-BN in contrast to LW-PLS.

      PubDate: 2017-12-13T02:45:14Z
      DOI: 10.1016/j.conengprac.2017.10.018
      Issue No: Vol. 72 (2017)
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
Home (Search)
Subjects A-Z
Publishers A-Z
Customise
APIs
Your IP address: 54.166.245.10
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-