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Journal Cover Control Engineering Practice
   [12 followers]  Follow    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 0967-0661
     Published by Elsevier Homepage  [2563 journals]   [SJR: 1.522]   [H-I: 59]
  • CEP special issue on power system control
    • Abstract: Publication date: Available online 17 May 2014
      Source:Control Engineering Practice
      Author(s): István Erlich



      PubDate: 2014-06-14T15:55:15Z
       
  • Bridging the gap between theory and practice in LPV fault detection for
           flight control actuators
    • Abstract: Publication date: Available online 6 June 2014
      Source:Control Engineering Practice
      Author(s): Bálint Vanek , András Edelmayer , Zoltán Szabó , József Bokor
      Two different approaches for fault detection, the geometric and the detection filter based methods, are compared in the paper from practical aspects, using the linear parameter-varying (LPV) framework. Presenting two designs allows a comparison of global, system level, and local component level fault detection methods with special emphasis on their relevance to aircraft industry. Practical engineering design decisions are highlighted via applying them to a high-fidelity commercial aircraft problem. The successive steps of the design, including fault modeling, LPV model generation, and LPV FDI filter synthesis, including implementation aspects, are discussed. Results are presented according to the industrial assessment perspectives phrased within the EU ADDSAFE project.


      PubDate: 2014-06-14T15:55:15Z
       
  • OBC - Autogenerate contents and barcode
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29




      PubDate: 2014-06-14T15:55:15Z
       
  • IFC - Editorial Board / Funding body / agreements policies
    • Abstract: Publication date: July 2014
      Source:Control Engineering Practice, Volume 28




      PubDate: 2014-06-14T15:55:15Z
       
  • OBC - Autogenerate contents and barcode
    • Abstract: Publication date: July 2014
      Source:Control Engineering Practice, Volume 28




      PubDate: 2014-06-14T15:55:15Z
       
  • Development and application of sliding mode LPV fault reconstruction
           schemes for the ADDSAFE
    • Abstract: Publication date: Available online 6 June 2014
      Source:Control Engineering Practice
      Author(s): Halim Alwi , Christopher Edwards
      This paper describes the development and the evaluation of a robust sliding mode observer fault detection scheme applied to an aircraft benchmark problem as part of the ADDSAFE project. The ADDSAFE benchmark problem which is considered in this paper is the yaw rate sensor fault scenario. A robust sliding mode sensor fault reconstruction scheme based on an LPV model is presented, where the fault reconstruction signal is obtained from the so-called equivalent output error injection signal associated with the observer. The development process includes implementing the design using AIRBUS׳s the so-called SAO library which allows the automatic generation of flight certifiable code which can be implemented on the actual flight control computer. The proposed scheme has been subjected to various tests and evaluations on the Functional Engineering Simulator conducted by the industrial partners associated with the ADDSAFE project. These were designed to cover a wide range of the flight envelope, specific challenging manoeuvres and realistic fault types. The detection and isolation logic together with a statistical assessment of the FDD schemes are also presented. Simulation results from various levels of FDD developments (from tuning, testing and industrial evaluation) show consistently good results and fast detection times.


      PubDate: 2014-06-14T15:55:15Z
       
  • Optimal energy management for an electric vehicle in eco-driving
           applications
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): Wissam Dib , Alexandre Chasse , Philippe Moulin , Antonio Sciarretta , Gilles Corde
      This paper considers an energy management problem for an electric vehicle compliant with online requirements for ‘eco-driving’ application. Eco-driving techniques are discussed and formulated as an optimal control problem that consists of the minimization of the vehicle consumption over a time and distance horizon. Then, a closed-form solution of the optimal trajectories is presented. Numerical and experimental results assess the validity of the proposed eco-driving system.


      PubDate: 2014-06-14T15:55:15Z
       
  • A control benchmark on the energy management of a plug-in hybrid electric
           vehicle
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): A. Sciarretta , L. Serrao , P.C. Dewangan , P. Tona , E.N.D. Bergshoeff , C. Bordons , L. Charmpa , Ph. Elbert , L. Eriksson , T. Hofman , M. Hubacher , P. Isenegger , F. Lacandia , A. Laveau , H. Li , D. Marcos , T. Nüesch , S. Onori , P. Pisu , J. Rios , E. Silvas , M. Sivertsson , L. Tribioli , A.-J. van der Hoeven , M. Wu
      A benchmark control problem was developed for a special session of the IFAC Workshop on Engine and Powertrain Control, Simulation and Modeling (E-COSM 12), held in Rueil-Malmaison, France, in October 2012. The online energy management of a plug-in hybrid-electric vehicle was to be developed by the benchmark participants. The simulator, provided by the benchmark organizers, implements a model of the GM Voltec powertrain. Each solution was evaluated according to several metrics, comprising of energy and fuel economy on two driving profiles unknown to the participants, acceleration and braking performance, computational performance. The nine solutions received are analyzed in terms of the control technique adopted (heuristic rule-based energy management vs. equivalent consumption minimization strategies, ECMS), battery discharge strategy (charge depleting–charge sustaining vs. blended mode), ECMS implementation (vector-based vs. map-based), ways to improve the implementation and improve the computational performance. The solution having achieved the best combined score is compared with a global optimal solution calculated offline using the Pontryagin's minimum principle-derived optimization tool HOT.


      PubDate: 2014-06-14T15:55:15Z
       
  • Optimal energy management for a diesel hybrid electric vehicle considering
           transient PM and quasi-static NOx emissions
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): Tobias Nüesch , Mu Wang , Pascal Isenegger , Christopher H. Onder , Rüdiger Steiner , Pedro Macri-Lassus , Lino Guzzella
      In this paper, optimal energy management strategies are derived to balance fuel consumption, raw particulate matter (PM) emissions, and raw nitrogen oxide (NOx) emissions for a Diesel hybrid electric vehicle. Two methods for the derivation of these strategies are compared. One method is based on dynamic programming and steady-state engine maps only. The second method is based on dynamic programming, steady-state engine maps, and a validated transient PM emission model. As a result, only the second method allows for the generation of smooth engine set point trajectories to reduce transient PM emissions without compromising fuel consumption and NOx emissions.


      PubDate: 2014-06-14T15:55:15Z
       
  • Hardware-in-the-loop validation of a power management strategy for hybrid
           powertrains
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): Youngki Kim , Ashwin Salvi , Jason B. Siegel , Zoran S. Filipi , Anna G. Stefanopoulou , Tulga Ersal
      Previously, a hybrid powertrain management strategy was developed that controls the power sources based on frequency content, mitigating aggressive engine transients. This article presents a hardware-in-the-loop validation of this strategy, with a real engine and battery integrated into a diesel hybrid electric vehicle simulation, thereby allowing for a realistic evaluation of fuel economy, soot emissions, and battery life. Considering an aggressive drive cycle and a state-of-charge regulation strategy as a benchmark, the frequency-based strategy yields 5.9% increase in fuel economy, 62.7% decrease in soot emissions, and 23% reduction in effective Amp-hours processed, which should yield an increase in battery life.


      PubDate: 2014-06-14T15:55:15Z
       
  • A stochastic method for the energy management in hybrid electric vehicles
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): F. Payri , C. Guardiola , B. Pla , D. Blanco-Rodriguez
      There are many approaches addressing the problem of optimal energy management in hybrid electric vehicles; however, most of them optimise the control strategy for particular driving cycles. This paper takes into account that the driving cycle is not a priori known to obtain a near-optimal solution. The proposed method is based on analysing the power demands in a given receding horizon to estimate future driving conditions and minimise the fuel consumption while cancelling the expected battery energy consumption after a defined time horizon. Simulations show that the proposed method allows charge sustainability providing near-optimal results.


      PubDate: 2014-06-14T15:55:15Z
       
  • Nonlinear cascade strategy for longitudinal control in automated vehicle
           guidance
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): Rachid Attia , Rodolfo Orjuela , Michel Basset
      This paper deals with automatic control design for automotive driving with a special focus on the longitudinal control. The automotive vehicle is a complex system characterised by highly nonlinear longitudinal and lateral coupled dynamics. Consequently, the control design for automated driving should deal with both of these dynamic couplings. Indeed, the longitudinal control plays an important role in the automated guidance to ensure safety and comfort of automotive passengers. In this work, a nonlinear cascade longitudinal control based on inner and outer-loops design is proposed. The lateral control is handled following a model predictive approach ensuring the automated steering of the vehicle. Finally, the nonlinear longitudinal control is integrated with the lateral control in a whole architecture to perform a coupled longitudinal and lateral control. The effectiveness of the automated driving strategy is highlighted through simulation results.


      PubDate: 2014-06-14T15:55:15Z
       
  • Insight into the HEV/PHEV optimal control solution based on a new tuning
           method
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): C. Guardiola , B. Pla , S. Onori , G. Rizzoni
      The paper presents a formulation of the energy management problem for Hybrid Electrical Vehicles and Plug-in Hybrid Electrical Vehicles alike, which permits to consider different cost indexes like fuel consumption, total and primary energy consumption, economic cost or CO2 footprint. In-depth analysis of the problem optimal solution is done by means of the application of the λ - plot method, which also permits the optimal tuning of other implementable control strategies. Such an approach is used to understand the effect of the selected cost index, the regional energetic share, the driving conditions, and for deriving rules for battery sizing.


      PubDate: 2014-06-14T15:55:15Z
       
  • Experimental implementation of distributed flocking algorithm for multiple
           robotic fish
    • Abstract: Publication date: September 2014
      Source:Control Engineering Practice, Volume 30
      Author(s): Yongnan Jia , Long Wang
      This paper presents the experimental implementation of a flocking algorithm for multiple robotic fish governed by extended second-order unicycles. Combing consensus protocols with attraction/repulsion functions, a flocking algorithm is proposed to make the agents asymptotically converge to swim with consistent velocities and approach the equilibrium distances to their neighbors. The LaSalle–Krasovskii invariance principle is applied to verify the stability of the system. Besides numerical simulations, platform simulations involving robotic fish kinematic constraint and control mechanism are shown. An experiment with three robotic fish is implemented to illustrate the effectiveness of the proposed flocking algorithm in the presence of external disturbance and boundary collision.


      PubDate: 2014-06-14T15:55:15Z
       
  • Dynamic surface control of a piezoelectric fuel injector during rate
           shaping
    • Abstract: Publication date: September 2014
      Source:Control Engineering Practice, Volume 30
      Author(s): Dat Le , Bradley W. Pietrzak , Gregory M. Shaver
      Fuel injection rate shaping is a strategy to improve fuel efficiency and reduce harmful emissions in diesel engines. Due to their fast response, piezoelectric fuel injectors are capable of rate shaping operation. This paper describes a model-based closed-loop controller of injection flow rate for a piezoelectric fuel injector. This within-an-engine-cycle control strategy utilizes a dynamic surface control scheme and shows an injection flow rate tracking capability. Practical issues with LabVIEW FPGA control implementation are also addressed. The performance of the controller is verified with simulation and experimental results at different rail pressures and desired injection rates. The experiments show a maximum error of total fuel per one injection event of 2.5%. A stability analysis is also included.


      PubDate: 2014-06-14T15:55:15Z
       
  • Supervisory control of air–fuel ratio in spark ignition engines
    • Abstract: Publication date: September 2014
      Source:Control Engineering Practice, Volume 30
      Author(s): Denis V. Efimov , Vladimir O. Nikiforov , Hossein Javaherian
      The problem of air–fuel ratio stabilization in spark ignition engines is addressed in this paper. The proposed strategy consists of proper switching among two control laws to improve quality of the closed-loop system. The first control law is based on an a priori off-line identified engine model and ensures robust and reliable stabilization of the system at large, while the second control law is adaptive, it provides on-line adaptive adjustment to the current fluctuations and improves accuracy of the closed-loop system. The supervisor realizes a switching rule between these control laws providing better performance of regulation. Results of implementation on two vehicles are reported and discussed.


      PubDate: 2014-06-14T15:55:15Z
       
  • IFC - Editorial Board / Funding body / agreements policies
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29




      PubDate: 2014-06-14T15:55:15Z
       
  • Probability density function of bubble size based reagent dosage
           predictive control for copper roughing flotation
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): Jianyong Zhu , Weihua Gui , Chunhua Yang , Honglei Xu , Xiaoli Wang
      As an effective measurement indicator of bubble stability, bubble size structure is believed to be closely related to flotation performance in copper roughing flotation. Moreover, reagent dosage has a very important influence on bubble size structure. In this paper, a novel reagent dosage predictive control method based on probability density function (PDF) of bubble size is proposed to implement the indices of roughing circuit. Firstly, the froth images captured in the copper roughing are segmented by using a two-pass watershed algorithm. In order to characterize bubble size structure with non-Gaussian feature, an entropy based B-spline estimator is hence investigated to depict the PDF of the bubble size. Since the weights of B-spline are interrelated and related to the reagent dosage, a multi-output least square support vector machine (MLS-SVM) is applied to depict a dynamic relationship between the weights and the reagent dosage. Finally, an entropy based optimization algorithm is proposed to determine reagent dosage in order to implement tracking control for the PDF of the output bubble size. Experimental results can show the effectiveness of the proposed method.


      PubDate: 2014-06-14T15:55:15Z
       
  • Set-membership methods applied to identify high-frequency elements of EMI
           filters
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): Nacim Meslem , Vu Tuan Hieu Le , Cécile Labarre , Stéphane Lecoeuche , Jean-Luc Kotny , Nadir Idir
      In order to enhance the performance of electromagnetic interference (EMI) filters, it is necessary to identify high-frequency parasitic elements of their passive components, mainly those related to the coupled inductors. Motivated by this issue, in this work a realistic high-frequency model is proposed for the coupled inductors. Actually, using interval analysis in particular the forward–backward contractor, a set-membership algorithm has been developed to estimate systematically the parasitic elements linked with the magnetic components. The main advantages of this algorithm compared to the fitting methods are the values of the estimated parameters are always positive and the corrupted data are taken into account. The comparison of the simulation results and the experimental data allows us to validate the proposed method.


      PubDate: 2014-06-14T15:55:15Z
       
  • Data-based automated diagnosis and iterative retuning of
           proportional-integral (PI) controllers
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): Tim Spinner , Babji Srinivasan , Raghunathan Rengaswamy
      This work presents a new look at the existing data-based and non-intrusive PI (proportional-integral) controller tuning assessment methods for SISO (single-input single-output) systems under regulatory control. Poorly tuned controllers are a major contributor to performance deterioration in process industries both directly and indirectly, as in the case of actuator cycling and eventual failure due to aggressive tuning. In this paper, an extensive review and classification of performance assessment and automated retuning algorithms, both classical and recent is provided. A subset of more recent algorithms that rely upon classification of poor tuning into the general categories of sluggish tuning and aggressive tuning are compared by their diagnostic performance. The Hurst exponent is introduced as a method for diagnosis of sluggish and aggressive control loop tuning. Also, a framework for more rigorous definitions than previously available of the terms “sluggish tuning” and “aggressive tuning” are provided herein. The performance of several tuning diagnosis methods are compared, and new algorithms for using these tuning diagnosis methods for iterative retuning of PI controllers are proposed and investigated using simulation studies. The results of these latter studies highlight the possible problem of loop instability when retuning based upon the diagnoses provided by data-based measures.


      PubDate: 2014-06-14T15:55:15Z
       
  • Coordinated trajectory planning for efficient communication relay using
           multiple UAVs
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): Seungkeun Kim , Hyondong Oh , Jinyoung Suk , Antonios Tsourdos
      This paper investigates the use of small UAVs as communication relay nodes for expanding communication links and improving communication quality for a fleet of naval vessels. This paper firstly deals with the UAV deployment for stationary communication nodes, and then, proposes a decentralised nonlinear model predictive trajectory planning strategy for a dynamic environment. By exploiting motion estimates of vessels and states of UAVs, the trajectory planning algorithm finds a control input sequence optimising network connectivity over a certain time horizon. Numerical simulations are performed for both stationary and manoeuvring vessels to verify the feasibility and benefit of the proposed approach.


      PubDate: 2014-06-14T15:55:15Z
       
  • Nonlinear thermal system identification using fractional Volterra series
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): Asma Maachou , Rachid Malti , Pierre Melchior , Jean-Luc Battaglia , Alain Oustaloup , Bruno Hay
      Linear fractional differentiation models have already proven their efficacy in modeling thermal diffusive phenomena for small temperature variations involving constant thermal parameters such as thermal diffusivity and thermal conductivity. However, for large temperature variations, encountered in plasma torch or in machining in severe conditions, the thermal parameters are no longer constant, but vary along with the temperature. In such a context, thermal diffusive phenomena can no longer be modeled by linear fractional models. In this paper, a new class of nonlinear fractional models based on the Volterra series is proposed for modeling such nonlinear diffusive phenomena. More specifically, Volterra series are extended to fractional derivatives, and fractional orthogonal generating functions are used as Volterra kernels. The linear coefficients are estimated along with nonlinear fractional parameters of the Volterra kernels by nonlinear programming techniques. The fractional Volterra series are first used to identify thermal diffusion in an iron sample with data generated using the finite element method and temperature variations up to 700K. For that purpose, the thermal properties of the iron sample have been characterized. Then, the fractional Volterra series are used to identify the thermal diffusion with experimental data obtained by injecting a heat flux generated by a 200W laser beam in the iron sample with temperature variations of 150K. It is shown that the identified model is always more accurate than the finite element model because it allows, in a single experiment, to take into account system uncertainties.


      PubDate: 2014-06-14T15:55:15Z
       
  • A highly scalable path-following controller for N-trailers with off-axle
           hitching
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): Maciej Marcin Michałek
      The paper presents a highly scalable nonlinear cascaded-like path-following feedback controller for N-trailer robotic vehicles equipped with arbitrary number of off-axle hitched trailers. In contrast to the other path-following control laws proposed in the literature for N-trailer robots, the presented control approach does not require determination of the shortest distance to a reference path. By introducing the so-called segment-platooning reference paths, and under the sign-homogeneity assumption for hitching offsets, the asymptotic following is guaranteed for both constant- and varying-curvature reference paths using either backward or forward vehicle motion strategy with a guidance point fixed on the last trailer. The paper contains experimental results obtained with a 3-trailer laboratory-scale vehicle.


      PubDate: 2014-06-14T15:55:15Z
       
  • Gradient-based optimization algorithms for networks of reconfigurable
           sensors
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): T.H. de Groot , O.A. Krasnov , A.G. Yarovoy
      A variety of optimization algorithms has been developed for non-linear and non-convex problems in which numerous reconfigurable sensors need to be assigned to many tasks. The algorithms are based on modified gradient-search methods and inspired by centralized/distributed principles. Numerical evaluation of these algorithms on a statistically large set of optimization problems has shown that while each particular algorithm does not necessarily provide the optimal solution in all possible cases, some are very efficient in solving them. Distributed (agent-based) approaches are usually advocated because of their scalability and speed, but the developed centralized (synchronous) algorithms are shown to be better in terms of speed, and simultaneously in terms of effectiveness, and therefore, in terms of efficiency.


      PubDate: 2014-06-14T15:55:15Z
       
  • Combining extremum seeking control and tracking control for
           high-performance CVT operation
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): Stan van der Meulen , Bram de Jager , Frans Veldpaus , Maarten Steinbuch
      The design of a new controller for the variator in a pushbelt continuously variable transmission (CVT) is investigated. A conventional variator controller is typically based on a variator model with large uncertainties, which results in a limited variator efficiency. The proposed controller simultaneously optimizes the variator efficiency and tracks a transmission ratio reference, for which a detailed variator model is not required. The controller, a combination of extremum seeking control and tracking control, only uses measurements from standard sensors. Experiments on the basis of a driving cycle show that a conventional variator controller is outperformed.


      PubDate: 2014-06-14T15:55:15Z
       
  • Model-based diesel Engine Management System optimization for transient
           engine operation
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): Markus Grahn , Krister Johansson , Tomas McKelvey
      A recently developed strategy to calculate set points for controllable diesel engine systems is described, further developed, and evaluated. The strategy calculates set points with an aim to minimize fuel consumption for a given dynamic vehicle driving cycle, while keeping accumulated emissions below given limits. The strategy is based on existing methodology for steady-state engine operation, but extended to handle transient effects in the engine caused by dynamics in the engine air system. Using the strategy, set points for the complete operating range of the engine can be calculated off-line and stored in an Engine Management System, hence set points can be derived for any (steady-state or transient) driving scenario. The strategy has been evaluated using a simulation model of a complete diesel engine vehicle system. The model estimates fuel consumption, NO X , and soot emissions for a dynamic vehicle driving cycle depending on set points for boost pressure, oxygen fraction in the intake manifold, and injection timing, throughout the simulation. Using this simulation model, the strategy has been shown to decrease fuel consumption for the New European Driving Cycle with 0.56%, the Federal Test Procedure with 1.04%, and the Japanese JC08 cycle with 0.84% compared to a strategy based on steady-state engine operation.


      PubDate: 2014-06-14T15:55:15Z
       
  • Direct multivariable controller tuning for internal combustion engine test
           benches
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): Thomas E. Passenbrunner , Simone Formentin , Sergio M. Savaresi , Luigi del Re
      Dynamical test benches are typically used in the development phase of engine systems and require tracking controllers with a high performance. Unfortunately, during such a work the components or operation parameters of the engine system are changed very frequently, making the use of classical model based control approaches very time-consuming. Against this background, this paper proposes a direct data-driven design approach for multivariable control of rotational speed and shaft torque of an internal combustion engine at a test bench based on an extended version of a recently introduced method for non-iterative direct data-driven tuning of multivariable controllers. This extension allows employing data collected in a closed-loop experiment in the direct identification of the controller parameters. The effectiveness of the proposed approach is shown on a test bench equipped with a production light duty Diesel engine. A comparison with the industrial state-of-the-art controller is provided on both a dynamically challenging test and a typical driving cycle as measured on an instrumented vehicle with the same internal combustion engine. The results confirm that the new method recovers the performance of the well-tuned industrial control, but can be developed in a fraction of the time as no explicit model of the system is needed.


      PubDate: 2014-06-14T15:55:15Z
       
  • Planar feature-based motion control for near-repetitive structures
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): J.J.T.H. de Best , M.J.G. van de Molengraft , M. Steinbuch
      This paper focuses on the motion control for machines used for the production of products that inherently consist of equal features placed in a repetitive pattern. In many cases the repetitiveness of these structures is prone to imperfections, for example due to thermal expansion, such that the distance between successive features deviates. As a consequence the metric positions of the features of such near-repetitive structures are unknown a priori such that setpoints cannot be created a priori. The considered motion task in this paper is to position a tool relative to the features of a near-repetitive structure with an accuracy of < 10 μ m . Instead of metric positions novel two-dimensional feature-based positions will be used that are obtained from a camera capturing images at 1kHz for feedback, resulting in a direct visual servoing control approach. The robustness with respect to imperfections in the repetitiveness is investigated and the design is validated on an experimental setup.


      PubDate: 2014-06-14T15:55:15Z
       
  • Sea floor geometry approximation and altitude control of ROVs
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): Fredrik Dukan , Asgeir J. Sørensen
      This paper presents a method for sea floor geometry approximation in a local region beneath a remotely operated vehicle (ROV) for use in altitude control. The method is based on Doppler velocity log (DVL) altitude measurements and ROV state estimates. The ROV altitude and sea floor gradient, which are obtained from the sea floor approximation, are used in a guidance law for altitude control. The altitude observer and guidance law have been implemented in the control system of NTNU׳s ROV Minerva. Results from simulations and sea trials demonstrating the performance of the proposed altitude estimation and guidance system are presented in the paper.


      PubDate: 2014-06-14T15:55:15Z
       
  • A brand new nonlinear robust control design of SSSC for transient
           stability and damping improvement of multi-machine power systems via
           pseudo-generalized Hamiltonian theory
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): Bangjun Lei , Shumin Fei
      Nonlinear robust control of static synchronous series compensator (SSSC) is investigated in multi-machine multi-load power systems by using the pseudo-generalized Hamiltonian method. First, the uncertain nonlinear differential algebraic equation model is constructed for the power system. Then, the dissipative pseudo-generalized Hamiltonian realization of the system is established by means of variable transformation and prefeedback control. Finally, based on the obtained dissipative pseudo-generalized Hamiltonian realization, a brand new nonlinear robust controller is put forward. The proposed controller can effectively use the internal structure and the energy balance property of the power system. Simulation results demonstrate the effectiveness and robustness of the control scheme.


      PubDate: 2014-06-14T15:55:15Z
       
  • Assessment of gradient-based iterative learning controllers using a
           multivariable test facility with varying interaction
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): Thanh V. Dinh , Chris T. Freeman , Paul L. Lewin
      A multiple input, multiple output (MIMO) experimental test facility has been developed for the evaluation, benchmarking and comparison of iterative learning control (ILC) strategies. The system addresses the distinct lack of experimental studies for the multivariable case and enables controller performance and robustness to be rigorously investigated over a broad range of operating conditions. The electromechanical facility is multi-configurable with up to 3 inputs and permits both exogenous disturbance injection and a variable level of coupling to be applied between input and output pairs. To confirm its suitability for evaluation and comparison of ILC, theoretical results are derived for two popular forms of gradient-type ILC algorithm, linking interaction with fundamental performance limitations. The test facility is then used to establish how well theoretical predictions match experimental results. The analysis is then extended to provide solutions to address this performance degradation, and these are again confirmed using the test facility.


      PubDate: 2014-06-14T15:55:15Z
       
  • Editorial: IFAC Workshop on Engine and Powertrain Control, Simulation and
           Modeling (ECOSM 2012)
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): Antonio Sciarretta , Paolino Tona , Chris Manzie , Carlos Guardiola



      PubDate: 2014-06-14T15:55:15Z
       
  • Cascaded control of combustion and pollutant emissions in diesel engines
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): Frédéric Tschanz , Stephan Zentner , Christopher H. Onder , Lino Guzzella
      Control of the emissions of diesel engines is an upcoming approach for complying with legislation while limiting the calibration effort. In this paper, a controller for engine-out NOx and PM is combined with a controller for the center of main combustion and the indicated mean effective pressure. The inner cascade combustion controller effectively reduces unwanted influences on the combustion. These influences are partly coupled to the outer-loop manipulated variables and partly result from disturbances which commonly appear in diesel engines. Robust stability is analyzed and holds in a wide operating range. Performance of the control structure is demonstrated with experiments.


      PubDate: 2014-06-14T15:55:15Z
       
  • Robust oxygen fraction estimation for conventional and premixed charge
           compression ignition engines with variable valve actuation
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): Lyle E. Kocher , Carrie M. Hall , Karla Stricker , David Fain , Dan Van Alstine , Gregory M. Shaver
      In-cylinder oxygen fraction serves as a critical control input to advanced combustion strategies, but is extremely difficult to measure on production engines. Fortunately, the in-cylinder oxygen levels can be estimated based on accurate estimates or measurements of the oxygen fraction in the intake and exhaust manifolds, the in-cylinder charge mass, and the residual mass. This paper outlines such a physically based, generalizable strategy to estimate the in-cylinder oxygen fraction from only production viable measurements or estimates of exhaust oxygen fraction, fresh air flow, charge flow, fuel flow, turbine flow and EGR flow. While several of these flows are accurately measured or estimated, significant errors in the turbine and EGR flows are commonly observed and can highly degrade the accuracy of any calculations which utilize these flows. An EGR flow estimator was developed to improve the accuracy of this flow measurement over the stock engine control module (ECM) method and is detailed in this paper. Furthermore, the in-cylinder oxygen estimation algorithm is developed, and proven, to be robust to turbine flow errors. Regulation of in-cylinder oxygen levels is of interest for not only in conventional combustion modes but also in advanced combustion strategies such as premixed charge compression ignition. The proposed oxygen fraction estimator is designed such that its performance and stability is ensured in both conventional and advanced combustion modes. The model-based observer estimates the oxygen fractions to be within 0.5% O2 and is shown to have exponential estimator error convergence with a time constant less than 0.05s, even with turbine flow errors of up to 25%.


      PubDate: 2014-06-14T15:55:15Z
       
  • Online optimization of spark advance in alternative fueled engines using
           extremum seeking control
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): Alireza Mohammadi , Chris Manzie , Dragan Nešić
      Alternative fueled engines offer greater challenges for engine control courtesy of uncertain fuel composition. This makes optimal tuning of input parameters like spark advance extremely difficult in most existing ECU architectures. This paper proposes the use of grey-box extremum seeking techniques to provide real-time optimization of the spark advance in alternative fueled engines. Since practical implementation of grey-box extremum seeking methods is typically done using digital technology, this paper takes advantage of emulation design methods to port the existing continuous-time grey-box extremum seeking methods to discrete-time frameworks. The ability and flexibility of the proposed discrete-time framework is demonstrated through simulations and in practical situation using a natural gas fueled engine.


      PubDate: 2014-06-14T15:55:15Z
       
  • Model based approach to closed loop control of 1-D engine simulation
           models
    • Abstract: Publication date: August 2014
      Source:Control Engineering Practice, Volume 29
      Author(s): Dariusz Cieslar , Paul Dickinson , Alex Darlington , Keith Glover , Nick Collings
      1-D engine simulation models are widely used for the analysis and verification of air-path design concepts to assess performance and therefore determine suitable hardware. The transient response is a key driver in the selection process which in most cases requires closed loop control of the model to ensure operation within prescribed physical limits and tracking of reference signals. Since the controller effects the system performance a systematic procedure which achieves close-to-optimal performance is desired, if the full potential of a given hardware configuration is to be properly assessed. For this purpose a particular implementation of Model Predictive Control (MPC) based on a corresponding Mean Value Engine Model (MVEM) is reported here. The MVEM is linearised on-line at each operating point to allow for the formulation of quadratic programming (QP) problems, which are solved as the part of the proposed MPC algorithm. The MPC output is used to control a 1-D engine model. The closed loop performance of such a system is benchmarked against the solution of a related optimal control problem (OCP). The system is also tested for operation at high altitude conditions to demonstrate the ability of the controller to respect specified physical constraints. As an example this study is focused on the transient response of a light-duty automotive Diesel engine. For the cases examined the proposed controller design gives a more systematic procedure than other ad hoc approaches that require considerable tuning effort.


      PubDate: 2014-06-14T15:55:15Z
       
  • Robust online roll dynamics identification of a vehicle using sliding mode
           concepts
    • Abstract: Publication date: Available online 24 April 2014
      Source:Control Engineering Practice
      Author(s): Robert Tafner , Markus Reichhartinger , Martin Horn
      This paper proposes a robust observer concept for joint estimation of system states and model parameters related to the roll dynamics of a vehicle. Using sliding mode concepts introduces robustness to parametric uncertainties and also allows reconstruction of the latter. These model parameters are of interest for vehicle dynamics assessment and estimation of the roll angle. A novel classification concept exploits these parameter estimates for assessing the roll dynamics. An additional benefit of the proposed method is the minimal requirement of measurement equipment as it only relies on cost-efficient angular rate and acceleration sensors. Evaluation of the framework is performed in simulations and real-world using an experimental vehicle.


      PubDate: 2014-04-29T06:47:05Z
       
  • An automatic tuning methodology for a unified dead-time compensator
    • Abstract: Publication date: May 2014
      Source:Control Engineering Practice, Volume 27
      Author(s): Julio E. Normey-Rico , Rafael Sartori , Massimiliano Veronesi , Antonio Visioli
      In this paper, an automatic tuning methodology for a modified Smith predictor control scheme is proposed. The main feature of the procedure is that it is applied in closed-loop (by either evaluating a set-point or a load disturbance step response) and it is suitable for self-regulating, integral and unstable processes. Further, the process parameter estimation technique is based on the evaluation of the integral of signals, thus making it inherently robust to measurement noise. Simulation and experimental results demonstrate the effectiveness of the methodology.


      PubDate: 2014-04-29T06:47:05Z
       
  • New Damped-Jerk trajectory for vibration reduction
    • Abstract: Publication date: June 2014
      Source:Control Engineering Practice, Volume 28
      Author(s): Richard Béarée
      This paper derives a jerk-shaped profile to address the vibration reduction of underdamped flexible dynamics of motion system. The jerk-limited profile is a widespread smooth command pattern used by modern motion systems. The ability of the jerk-limited profile to cancel the residual vibration of an undamped flexible mode is clearly explained using an equivalent continuous filter representation and the input shaping formalism. This motivates the design of a new jerk-shaped profile, named Damped-Jerk profile, to extend the previous result to the more common case of underdamped systems. Both simulations and experimental results demonstrate the effectiveness of the proposed Damped-Jerk profile to reduce damped vibration.


      PubDate: 2014-04-29T06:47:05Z
       
  • IFC - Editorial Board / Funding body / agreements policies
    • Abstract: Publication date: May 2014
      Source:Control Engineering Practice, Volume 27




      PubDate: 2014-04-29T06:47:05Z
       
  • Extended complex Kalman filter for sensorless control of an induction
           motor
    • Abstract: Publication date: May 2014
      Source:Control Engineering Practice, Volume 27
      Author(s): Francesco Alonge , Filippo D׳Ippolito , Adriano Fagiolini , Antonino Sferlazza
      This paper deals with the design of an extended complex Kalman filter (ECKF) for estimating the state of an induction motor (IM) model, and for sensorless control of systems employing this type of motor as an actuator. A complex-valued model is adopted that simultaneously allows a simpler observability analysis of the system and a more effective state estimation. The observability analysis of this model is first performed by assuming that a third order ECKF has to be designed, by neglecting the mechanical equation of the IM model, which is a valid hypothesis when the motor is operated at constant rotor speed. It is shown that this analysis is more effective and easier than the one performed on the corresponding real-valued model, as it allows the observability conditions to be directly obtained in terms of stator current and rotor flux complex-valued vectors. Necessary observability conditions are also obtained along with the well-known sufficient ones. It is also shown that the complex-valued implementation allows a reduction of 35% in the computation time w.r.t. the standard real-valued one, which is obtained thanks to the lower dimensions of the matrices of the ECKF w.r.t. the ones of the real-valued implementation and the fact that no matrix inversion is required. The effectiveness of the proposed ECKF is shown by means of simulation in Matlab/Simulink environment and through experiments on a real low-power drive.


      PubDate: 2014-04-29T06:47:05Z
       
  • An output feedback LPV control strategy of a nonlinear electrostatic
           microgripper through a singular implicit modeling
    • Abstract: Publication date: June 2014
      Source:Control Engineering Practice, Volume 28
      Author(s): Mokrane Boudaoud , Marcelo Gaudenzi De Faria , Yann Le Gorrec , Yassine Haddab , Philippe Lutz
      The aim of the paper is the design and the analysis of a gain scheduled controller for an accurate and fast positioning with nanometer resolution of a nonlinear electrostatic microgripper. The controller is designed to achieve a positioning of the gripping arm from few hundred nanometers to several tens of micrometers with some performance criteria. This very large operating range is crucial for a range of microrobotics applications and has never been addressed in existing control techniques of microgrippers. The controller is designed considering noises that are relevant at the nanometer scale and nonlinearities that become significant at the micrometer scale. Therefore, a nonlinear model of the system is proposed and is reformulated into a polynomial LPV (Linear Parameter Varying) model. The most relevant source of noise to be considered for the controller synthesis is defined taking into account results from previous works. Considering the particular polynomial parametric dependence of the LPV model, a multivariable controller is designed using an affine LPV descriptor representation of the system and specific linear matrix inequalities. The efficiency of the controller and the relevance of the theoretical approach is demonstrated through experimental implementation results.


      PubDate: 2014-04-29T06:47:05Z
       
  • Probabilistic Weighted NPE-SVDD for chemical process monitoring
    • Abstract: Publication date: June 2014
      Source:Control Engineering Practice, Volume 28
      Author(s): Qingchao Jiang , Xuefeng Yan
      Probabilistic Weighted Neighborhood Preserving Embedding and Support Vector Data Description (WNPE-SVDD) is proposed to improve chemical process monitoring performance. First, the NPE that is a linear approximation of Locally Linear Embedding is used for dimensionality reduction. Then, a probabilistic weighting strategy is proposed to solve the suppression of useful information by highlighting useful information and removing irrelevant information. Finally, SVDD is used to assess the process status. Case studies on a numerical system, continuously simulated stirred tank reactor process, and Tennessee Eastman process are provided to demonstrate the efficiency of the WNPE-SVDD method.


      PubDate: 2014-04-29T06:47:05Z
       
  • Experimental comparison of backdrivability for time-delayed telerobotics
    • Abstract: Publication date: June 2014
      Source:Control Engineering Practice, Volume 28
      Author(s): Hongbing Li , Kenji Kawashima
      After stability, transparency is the major goal in teleoperation system design. This transparency goal of the overall system depends on the master/slave manipulator backdrivability. However, time delay in communication channel severely affects the backdrivability of a bilateral teleoperation system in practice. This study investigates the effects of communication delays on the backdrivability of a teleoperation system for wave-variable-based control techniques. The controllers are compared on position and force tracking performance using two identical linear robots coupled via network model that allowed random transmission round-trip delays. Overall, the comparison study reports a deteriorating effect in the system backdrivable performance (i.e., larger position errors and lower fidelity of contact information) from delays. In addition, wave-variable-based controller with position compensation is shown to make better system backdrivability.


      PubDate: 2014-04-29T06:47:05Z
       
  • Controller tuning using evolutionary multi-objective optimisation: Current
           trends and applications
    • Abstract: Publication date: June 2014
      Source:Control Engineering Practice, Volume 28
      Author(s): Gilberto Reynoso-Meza , Xavier Blasco , Javier Sanchis , Miguel Martínez
      Control engineering problems are generally multi-objective problems; meaning that there are several specifications and requirements that must be fulfilled. A traditional approach for calculating a solution with the desired trade-off is to define an optimisation statement. Multi-objective optimisation techniques deal with this problem from a particular perspective and search for a set of potentially preferable solutions; the designer may then analyse the trade-offs among them, and select the best solution according to his/her preferences. In this paper, this design procedure based on evolutionary multiobjective optimisation (EMO) is presented and significant applications on controller tuning are discussed. Throughout this paper it is noticeable that EMO research has been developing towards different optimisation statements, but these statements are not commonly used in controller tuning. Gaps between EMO research and EMO applications on controller tuning are therefore detected and suggested as potential trends for research.


      PubDate: 2014-04-29T06:47:05Z
       
  • A jerk-constrained time-optimal servo with disturbance compensation
    • Abstract: Publication date: June 2014
      Source:Control Engineering Practice, Volume 28
      Author(s): Yu-Sheng Lu , Raymond Shieh
      For positioning servo-systems, this paper presents a jerk-constrained time- optimal control (JCTOC) scheme, augmented with an improved disturbance rejection method. In mechanical systems, the jerk that is the time derivative of acceleration may cause many unwanted results when too high. Thus, the JCTOC method is proposed to constrain the system׳s jerk and also obtain a time-optimal characteristic with the constrained jerk. However, because the JCTOC relies on the accuracy of the plant׳s model, system uncertainties and disturbances can adversely affect the output response. Thus, a disturbance observer (DOB) is added for compensation of the perturbation. The DOB used in this paper is in an integral form, and is thus referred to as an integral DOB (IDOB). The IDOB is further enhanced with a dynamic compensator to provide both better noise immunity and asymptotic compensation for disturbances of various orders.


      PubDate: 2014-04-29T06:47:05Z
       
  • Nonlinear glucose–insulin control considering delays—Part II:
           Control algorithm
    • Abstract: Publication date: June 2014
      Source:Control Engineering Practice, Volume 28
      Author(s): K. Mythreyi , Shankar C. Subramanian , R. Krishna Kumar
      The closed loop control of blood glucose levels in a nonlinear glucose–insulin regulatory system is considered in this paper. Based on the subcutaneous glucose sensor readings, a control algorithm is designed and implemented. A mathematical model characterizing the ultradian oscillatory nature of the glucose–insulin regulatory system of diabetic patients is considered and an estimation based model predictive control scheme with physiological and actuator constraints is implemented. An in silico preclinical testing is done to corroborate the control algorithm using the UVa/Padova virtual patient software.


      PubDate: 2014-04-29T06:47:05Z
       
  • Online model predictive control of industrial processes using low level
           control hardware: A pilot-scale distillation column case study
    • Abstract: Publication date: June 2014
      Source:Control Engineering Practice, Volume 28
      Author(s): Bart Huyck , Jos De Brabanter , Bart De Moor , Jan F. Van Impe , Filip Logist
      Throughout the years, the computing power of industrial controllers has steadily increased. Together with the development of efficient quadratic program (QP) solvers, this raises the question whether these devices can host an online model predictive controller (MPC). The applicability of online MPC is investigated using a programmable automation controller (PAC) and a programmable logic controller (PLC) for the control of an industrially relevant process, i.e., a pilot scale distillation column. It is demonstrated that both devices are capable of hosting MPC, however the limitations of the PLC are reached for the investigated set-up. Finally, guidelines and pitfalls for use in practice are highlighted.


      PubDate: 2014-04-29T06:47:05Z
       
  • Data-driven diagnosis of PEM fuel cell: A comparative study
    • Abstract: Publication date: June 2014
      Source:Control Engineering Practice, Volume 28
      Author(s): Zhongliang Li , Rachid Outbib , Daniel Hissel , Stefan Giurgea
      This paper is dedicated to data-driven diagnosis for Polymer Electrolyte Membrane Fuel Cell (PEMFC). More precisely, it deals with water related faults (flooding and membrane drying) by using pattern classification methodologies. Firstly, a method based on physical considerations is defined to label the training data. Secondly, a feature extraction procedure is carried out to pick up the significant features from vectors constructed by individual cell voltages. Finally, a classification is adopted in the feature space to realize the fault diagnosis. Various feature extraction and classification methodologies are employed on a 20-cell PEMFC stack. The performances of these methodologies are compared.


      PubDate: 2014-04-29T06:47:05Z
       
  • Experimental verification of robustness in a semi-autonomous heavy vehicle
           platoon
    • Abstract: Publication date: June 2014
      Source:Control Engineering Practice, Volume 28
      Author(s): Gábor Rödönyi , Péter Gáspár , József Bokor , László Palkovics
      Novel numerical methods for analyzing robust peak-to-peak performance of heterogeneous vehicle platoons are presented. The goal is to compute worst-case spacing error peaks in terms of platoon heterogeneity, communication delays, disturbances and uncertainties in the vehicle dynamics. First, a convex set of parametric linear vehicle models is employed to analyze the effect of platoon heterogeneity. Then, a data-driven uncertainty modeling algorithm is developed that computes the least conservative spacing error bound for a given disturbance model class. The methods are demonstrated on three platoon controllers. One of them is a new constant spacing controller receiving control information from both the platoon leader and the immediate preceding vehicle.


      PubDate: 2014-04-29T06:47:05Z
       
 
 
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