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Showing papers by "M Maarten Steinbuch published in 2012"


Journal ArticleDOI
TL;DR: The control algorithm is developed based on the combination of dynamic programming and Pontryagin's minimum principle to optimally control the discrete gearshift command, in addition to the continuous power split between the internal combustion engine and the electric machine.
Abstract: This paper proposes a design method for the energy management strategy to explore the potential fuel saving of a hybrid electric vehicle (HEV) equipped with an automated manual transmission. The control algorithm is developed based on the combination of dynamic programming (DP) and Pontryagin's minimum principle (PMP) to optimally control the discrete gearshift command, in addition to the continuous power split between the internal combustion engine and the electric machine. The proposed method outperforms DP in terms of computational efficiency, being 171 times faster, without loss of accuracy. Simulation results for a middle-sized HEV on the New European Drive Cycle show that, to further optimize the gearshift strategy, an additional fuel saving of 20.3% can be reached. Furthermore, with the start-stop functionality available, it is shown that the two-point boundary-value problem following from PMP cannot be solved with sufficient accuracy without loss of optimality. This means that the finding of a constant value for the Lagrange multiplier while satisfying the battery state-of-energy (SOE) at the terminal time is not always guaranteed. Therefore, an alternative approach of SOE feedback control to adapt the Lagrange multiplier is adopted. The obtained results are very close to the globally optimal solution from DP. Simulation results, including the start-stop functionality, show that the relative fuel saving can be up to 26.8% compared with the case of a standard gearshift strategy.

118 citations


Journal ArticleDOI
TL;DR: The results provide a benchmark of the fuel-saving potential of this powertrain design and give insight into the optimal utilization of the flywheel system.
Abstract: This paper presents the design of an optimal energy management strategy (EMS) for a low-cost mechanical hybrid powertrain. It uses mechanical components only-a flywheel, clutches, gears, and a continuously variable transmission-for its hybrid functionalities of brake energy recuperation, reduction of inefficient part-load operation of the engine, and engine shutoff during vehicle standstill. This powertrain has mechanical characteristics, such as a relatively small energy storage capacity in the form of the compact flywheel and multiple driving modes to operate the powertrain because of the use of clutches. The optimization problem is complex because it is two fold: 1) to find the optimal sequence of driving modes and 2) to find the optimal power distribution between the engine, the flywheel, and the vehicle. Dynamic programming is used to compute the globally optimal EMS for six representative driving cycles. The main design criterion is the minimization of the overall fuel consumption, subject to the system's kinematics, dynamics, and constraints. The results provide a benchmark of the fuel-saving potential of this powertrain design and give insight into the optimal utilization of the flywheel system. In addition, the complexity (and computation time) of the problem is reduced by a priori (static) optimization of the power distribution for each driving mode. Static optimization of a dynamic optimization problem yields a suboptimal solution; however, the results show that the consequences on the fuel saving are small with respect to the optimal one (the difference is <; 0.8%).

58 citations


Journal ArticleDOI
TL;DR: In this article, a real-time optimal-control-based power split algorithm for hybrid electric vehicles is presented, which is adaptive for vehicle mass and road elevation, and is implemented on a standard Electronic Control Unit of a parallel hybrid electric truck.

50 citations


Journal ArticleDOI
TL;DR: In this paper, a frequency domain based method for controller design for nonlinear systems is presented, which is applied to optimally design a feed forward friction compensator for an industrial motion stage in a transmission electron microscope.

50 citations


Journal ArticleDOI
TL;DR: In this paper, an overview of the existing approaches and algorithms used for optimal design of hybrid electric vehicles (HEV) is presented, including an introduction in various hybrid topologies and examples from different transportation sectors.

47 citations


Journal ArticleDOI
TL;DR: In this brief, a controller is proposed that improves the efficiency without needing extra sensors, and can adapt the input to maximize the output, without needing a model.
Abstract: The design of an efficiency optimal controller for the variator in a vehicular continuously variable transmission is studied. A conventional controller aims at tracking a prescribed reference for the transmission ratio and at preventing damage, but does not address efficiency. Sufficiently accurate models for the efficiency as function of the clamping forces are not available, whereas measurement of the efficiency requires extra sensors. In this brief, a controller is proposed that improves the efficiency without needing extra sensors. The maps between the clamping forces (input) and the efficiency or the speed ratio (output) are studied with test rig experiments. These maps exhibit a maximum, but the location of this maximum is uncertain. So, an extremum seeking controller is developed. This controller can adapt the input to maximize the output, without needing a model. Experiments show that this approach is feasible and that a conventional controller is outperformed. A robustness analysis for disturbances indicates that these are effectively handled.

24 citations


Proceedings ArticleDOI
27 Jun 2012
TL;DR: A model-based controller is designed that solves the optimal control problem for a given equivalency between the energy sources, including the discrete control of start-stop and shifting, and converts to a Mixed-Integer Linear Program (MILP), which can be explicitly solved and stored on a real-time controller.
Abstract: The Energy Management System (EMS) in Hybrid Electric Vehicles (HEV) determines the optimal use of the available power resources to reduce the total fuel energy over a drive cycle. A real-time EMS that includes start-stop and gear selection in an optimal control framework, could not be found in literature. In this paper, a model-based controller is designed that solves the optimal control problem for a given equivalency between the energy sources, including the discrete control of start-stop and shifting. By approximating a validated vehicle model with piecewise affine functions, the controller converts to a Mixed-Integer Linear Program (MILP), which can be explicitly solved and stored on a real-time controller. In simulation the controller is able to outperform an EMS with heuristic control of start-stop and shifting: on a proprietary drive cycle, the number of gear shift events is reduced by 42%, the number of start-stop events is reduced by 6%, while at the same time fuel economy is improved by 0.3%.

23 citations


Proceedings ArticleDOI
31 Dec 2012
TL;DR: Using iterative learning control with basis functions for both positioning tasks, the positioning accuracy of the drive is improved substantially; while keeping numerical cost low.
Abstract: In printing systems, the positioning accuracy of the medium with respect to the print heads directly impacts print quality. In a regular document inkjet printer, the main task of the media positioning drive is to shift the medium after the printhead has finished a pass. Most media have the tendency to deform while it is being printed due to variations in temperature and moisture content. In order to improve print quality, we propose to move the medium during printing to counteract the deformation. These small scale trajectories are performed in an operating regime of which the dynamics considerably differ from the regular transportation step. Using iterative learning control with basis functions for both positioning tasks, the positioning accuracy of the drive is improved substantially; while keeping numerical cost low.

18 citations


Book ChapterDOI
01 Jan 2012
TL;DR: A robotic system to assist in vitreoretinal procedures has been developed, extending human capabilities beyond current limitations, and a successful peel of the inner shell membrane of the chorioallantoic membrane of a chicken egg has been achieved.
Abstract: To improve the time efficiency of current vitreoretinal surgical procedures and to enable new procedures demanding increased accuracy, a robotic system to assist in vitreoretinal procedures has been developed, extending human capabilities beyond current limitations. The robotic master–slave system is compact, lightweight and easy to set up. A combination of high-precision mechanical design and high-performance controller synthesis facilitates high accuracy down to 10 μm, tremor filtering, motion scaling, automated instrument changing an ergonomic body posture for the surgeon and haptic feedback. First functional tests with the demonstrator system show a short setup time, an intuitive usage and good ergonomics. With a knife and a pick, a successful peel of the inner shell membrane of the chorioallantoic membrane of a chicken egg has been achieved.

18 citations


Journal ArticleDOI
TL;DR: In this article, the authors describe the design and simulation of a tearing mode suppression feedback control system for the TEXTOR tokamak and demonstrate both alignment and width control of tearing modes in TEXTOR.
Abstract: Suppression of tearing modes is essential for the operation of tokamaks. This paper describes the design and simulation of a tearing mode suppression feedback control system for the TEXTOR tokamak. The two main control tasks of this feedback control system are the radial alignment of electron cyclotron resonance heating and current drive (ECRH/ECCD) with a tearing mode and the stabilization of a mode at a specific width. In order to simulate these control tasks, the time evolution of a tearing mode subject to suppression by ECRH/ECCD and destabilization by a magnetic perturbation field is modelled using the generalized Rutherford equation. The model includes an equilibrium model and an ECRH/ECCD launcher model. The dynamics and static equilibria of this model are analysed. The model is linearized and based on the linearized model, linear feedback controllers are designed and simulated, demonstrating both alignment and width control of tearing modes in TEXTOR.

15 citations


Journal ArticleDOI
TL;DR: Three control strategies for high-performance sawtooth control are presented using electron cyclotron current drive (ECCD) and time-domain simulations show that each strategy obtains a better closed-loop performance than standard linear feedback techniques on merely the deposition location.
Abstract: The sawtooth instability is associated with the triggering of neo-classical tearing modes, core fuelling, α-confinement and the exhaust of thermal helium. Sawtooth control is therefore important for optimal reactor performance in ELMy H-modes. Control schemes for the sawtooth period have been published in the literature, but the systematic design of high-performance controllers (yielding accurate and fast convergent responses) has not been addressed. In this work, three control strategies for high-performance sawtooth control are presented using electron cyclotron current drive (ECCD). Both degrees of freedom of the ECCD actuator will be explored and combined with advanced controller designs. First, the ECCD deposition location is used as a control variable, for which a gain-scheduled feedback controller and static feedforward control is derived. Second, the use of the driven current as a control variable is explored, and a simple controller is designed based on the identified dynamics. In the third approach both control variables are joined in an overall controller design, which enables the combination of high-performance control of the sawtooth period and control of the gyrotron power. Time-domain simulations with a combined Kadomtsev-Porcelli sawtooth model show that each strategy obtains a better closed-loop performance than standard linear feedback techniques on merely the deposition location. © 2012 IAEA, Vienna.

Journal ArticleDOI
TL;DR: The systematic design of a robust adaptive control strategy for the sawtooth period using electron cyclotron current drive (ECCD) is presented and is a valuable sawtoothing control candidate for any experimental tokamak plasma, and may even be applicable to other fusion-related control problems.
Abstract: The systematic design of a robust adaptive control strategy for the sawtooth period using electron cyclotron current drive (ECCD) is presented. Recent developments in extremum seeking control (ESC) are employed to derive an optimized controller structure and offer practical tuning guidelines for its parameters. In this technique a cost function in terms of the desired sawtooth period is optimized online by changing the ECCD deposition location based on online estimations of the gradient of the cost function. The controller design does not require a detailed model of the sawtooth instability. Therefore, the proposed ESC is widely applicable to any sawtoothing plasma or plasma simulation and is inherently robust against uncertainties or plasma variations. Moreover, it can handle a broad class of disturbances. This is demonstrated by time-domain simulations, which show successful tracking of time-varying sawtooth period references throughout the whole operating space, even in the presence of variations in plasma parameters, disturbances and slow launcher mirror dynamics. Due to its simplicity and robustness the proposed ESC is a valuable sawtooth control candidate for any experimental tokamak plasma, and may even be applicable to other fusion-related control problems. © 2012 IAEA, Vienna.

Journal ArticleDOI
TL;DR: This paper focusses on direct dynamic visual servoing at high sampling rates in machines used for the production of products that consist of equal features placed in a repetitive pattern.
Abstract: This paper focusses on direct dynamic visual servoing at high sampling rates in machines used for the production of products that consist of equal features placed in a repetitive pattern. The word “direct” means that the system at hand is controlled on the basis of vision only. More specifically, the motor inputs are driven directly by a vision-based controller without the intervention of low level joint controllers. The product in view consists of a repetitive pattern, which is used as an encoder purely on the basis of vision. The considered motion task is to position the repetitive structure in order to align the tool with respect to the features. The vision based controller is designed using classical loop shaping techniques. Robustness with respect to imperfections of the repetitiveness is investigated. The combination of fast image processing and a Kalman-filter-based predictor results in a 1 kHz visual servoing setup capable of exploiting the repetitive pattern as an encoder with an accuracy of 2 $\mu$ m. The design approach is validated on an experimental setup.

Proceedings ArticleDOI
27 Jun 2012
TL;DR: This paper presents a model-based feedforward method for over-actuated flexible motions systems, with non-collocated sensor and performance locations, that offers freedom to explore new control strategies that exploit the over-Actuation and -sensing.
Abstract: In high-performance motion systems, e.g. wafer-stages or pick-and-place machines, there is an increasing demand for higher throughput and accuracy. In the current design paradigm, i.e. rigid-body design, higher demands for throughput and accuracy will lead to a heavier machine. This paradigm does not scale anymore with higher throughputs, i.e. a new paradigm is required. The new paradigm is to design a lightweight machine and to deal with the resulting flexibilities by over-actuation and over-sensing. This class of systems offers freedom to explore new control strategies that exploit the over-actuation and -sensing. This paper presents a model-based feedforward method for over-actuated flexible motions systems, with non-collocated sensor and performance locations. Inferential control is considered as the point of interest for performance is typically different from the location of the measured feedback signals.

Journal ArticleDOI
TL;DR: This paper shows that the generalized frequency response function (GFRF) and the higher order sinusoidal input describing function (HOSIDF) for polynomial Wiener-Hammerstein systems are explicitly related, assuming the linear dynamics are known.

Journal ArticleDOI
TL;DR: In this article, the authors present an overview of mechanical-hybrid vehicle concepts found in the literature, and compare the fuel saving potential and the estimated cost of a selection of four competitive powertrain topologies.

Journal ArticleDOI
TL;DR: A general framework for the design of linear controllers for linear systems subject to time-domain constraints that offers the possibility of including an optimization objective that can be used to minimize steady state (tracking) errors, to decrease the settling time, to reduce overshoot and so on.

Proceedings ArticleDOI
27 Jun 2012
TL;DR: In this paper, a novel approach for next-generation motion control is presented, applied to a multivariable wafer stage, confirming a significant performance improvement in terms of throughput and accuracy.
Abstract: Next-generation precision motion systems are lightweight to meet stringent requirements regarding throughput and accuracy. Such lightweight systems typically exhibit lightly damped flexible dynamics in the controller cross-over region. State-of-the-art modeling and motion control design procedures do not deliver the required model fidelity to control the flexible dynamical behavior. In this paper, identification and control challenges are investigated and a novel approach for next-generation motion control is presented. The procedure is applied to a multivariable wafer stage, confirming a significant performance improvement.

Journal ArticleDOI
TL;DR: This work addresses the problem of control design for bilateral teleoperation systems by making use of a parametric model of the teleoperation system, which allows for independent bounds on the uncertain parameters without introducing conservatism in the model.

Journal ArticleDOI
TL;DR: In this paper, an optimal control algorithm for the start-stop, power split and gear shift problem based on Dynamic Programming-Pontryagin's Minimum Principle control approach is used to evaluate the effect of gear shift and engine start losses on the optimal solution.
Abstract: In this paper, energetic loss models in the events of shifting gear and starting engine in a parallel Hybrid Electric Vehicle equipped with an Automated Manual Transmission (AMT) will be introduced. The optimal control algorithm for the start-stop, power split and gear shift problem based on Dynamic Programming-Pontryagin’s Minimum Principle control approach is used to evaluate the effect of gear shift and engine start losses on the optimal solution. Furthermore, with preview route information available, a model predictive control algorithm is utilized to investigate the achievable fuel savings with respect to the prediction horizon. Under influence of the gear shift loss, simulation results of the prototype hybrid passenger car disclose a superior fuel efficiency property of the powershift AMT over its normal AMT counterpart. Sensitivity analysis of the traction force interruption time in a gear shift process can give a new perception on fuel economy benefit of powershift transmissions (e.g. automatic, dual clutch, powershift AMT, etc.) over a normal AMT. The study also reveals a minimum prediction length of 4s required for the design of such a realtime implementable controller to get the possible maximum fuel economy level under the impact of the engine start loss.

Journal ArticleDOI
TL;DR: In this paper, the authors presented a new design of a low-cost mechanical hybrid powertrain with large fuel savings, which consists of a compact flywheel module and a Continuously Variable Transmission (CVT).
Abstract: This paper presents a new design of a low-cost mechanicalhybrid powertrain with large fuel savings. The hybrid powertrain contains only low-cost mechanical components, such as a compact flywheel module and a Continuously Variable Transmission (CVT). No electrical motor/generator or battery is used. On the basis of the characteristics of typical driving cycles, the energy storage capacity of the flywheel module is derived accordingly. The fuel-saving potential of the new powertrain is simulated for a compact passenger vehicle, which represents the aimed vehicle segment in emerging markets. Simulations show that the fuel-saving potential, with respect to the same vehicle without flywheel module, ranges in between 15% and 29%, depending on the considered driving cycle.

Proceedings ArticleDOI
27 Jun 2012
TL;DR: Simulations show that the controller is robust against variations in plasma parameters, delay in the sawtooth crash detection, and noise on the in- and outputs of the process.
Abstract: The sawtooth instability is a repetitive phenomenon occurring in plasmas of tokamak nuclear fusion reactors. Experimental studies of these instabilities and the effect they have on the plasma (notably the drive of secondary instabilities and consequent performance reduction) for a wide variety of plasma conditions is an important line of study in nuclear fusion research. Variations in the plasma conditions have a significant influence on the dynamical behavior of the sawtooth instability. Therefore, this paper presents the design of a sawtooth period controller which is robust against such variations. The controller is from a class of adaptive controllers better known as extremum seekers. In this technique, a cost function in terms of the desired sawtooth period is optimized on-line. The Extremum Seeking Controller (ESC) is model-free and is therefore inherently robust against model uncertainty. Simulations show that the controller is robust against variations in plasma parameters, delay in the sawtooth crash detection, and noise on the in- and outputs of the process. Because of its robustness, ESC is a promising candidate strategy for a wide range of fusion-related control problems with high model uncertainty.

Proceedings Article
01 Jan 2012
TL;DR: A global planning architecture is conceptualized, based on the worldwide accessible RoboEarth cloud framework, that allows environmental state inference and plan monitoring on a global level and allows semantic matching of robot capabilities with previously composed plans.
Abstract: As robotic systems become more and more capable of assisting in human domains, methods are sought to compose robot executable plans from abstract human instructions. To cope with the semantically rich and highly expressive nature of human instructions, Hierarchical Task Network planning is often being employed along with domain knowledge to solve planning problems in a pragmatic way. Commonly, the domain knowledge is specific to the planning problem at hand, impeding re-use. Therefore this paper conceptualizes a global planning architecture, based on the worldwide accessible RoboEarth cloud framework. This architecture allows environmental state inference and plan monitoring on a global level. To enable plan re-use for future requests, the RoboEarth action language has been adapted to allow semantic matching of robot capabilities with previously composed plans.

01 Jan 2012
TL;DR: This paper presents a spatial feedforward method for over-actuated flexible motions systems, which aims at reducing the vibrations over the complete flexible structure during motion.
Abstract: In high-performance motion systems, e.g. waferstages or pick-and-place machines, there is an increasing demand for higher throughput and accuracy. The current design paradigm aims at rigid-body behaviour and leads in an evolutionary way to increasingly heavier systems that require more and more power. This paradigm is rapidly approaching the boundary of its scalability. A new paradigm is to design a lightweight machine and to deal with the resulting flexibilities by over-actuation and over-sensing. Such systems offer freedom to explore new control strategies that exploit the over-actuation and -sensing. This paper presents a spatial feedforward method for over-actuated flexible motions systems, which aims at reducing the vibrations over the complete flexible structure during motion. The proposed method is experimentally validated and compared to the standard input shaping technique.

01 Jan 2012
TL;DR: In this article, a method to compute decoupling matrices Fu and Fy that decouple the system in its rigid body(RB) modes and a number of non-rigid body(NRB) modes is presented.
Abstract: Current trends towards lightweight positioning systems from the lithography industry demand the usage of advanced servo control design methods that can actively control the unavoidable flexibilities. One solution is to use overactuation, [1], and over-sensing and to control the rigid and flexible modes of the system in a decentralized manner. Compared with the traditional decentralized control approach, in this work a more effective and a less conservative way towards a decentralized modal control is investigated for a 6 degrees of freedom motion stage. This paper describes a method to compute decoupling matrices Fu and Fy (Figure 1) that decouple the system in its rigid body(RB) modes and a number of non-rigid body(NRB) modes. Alignment and scaling of the rigid body modes are ensured. The decoupling enables the design of multi-loop SISO controllers, K, for the decoupled MIMO system, Gd.

Proceedings ArticleDOI
27 Jun 2012
TL;DR: The algorithm is designed for the control of the sawtooth instability, a relaxation oscillator, in fusion plasmas and can be applied to any periodic crash, measured with any temporally resolved data.
Abstract: In this article an algorithm for optimized realtime sensing of crashes for control purposes is presented. The algorithm is based on time-scale wavelet theory and edge-detection. It is designed for the control of the sawtooth instability, a relaxation oscillator, in fusion plasmas. However, in principle, it can be applied to any periodic crash, measured with any temporally resolved data. It is argued that the detection of crashes has considerably less delay and detects crashes with higher temporal accuracy than other linear methods; this holds especially for very noisy measurements.

Journal Article
TL;DR: A compact, lightweight, easy to setup robotic master-slave system has been realized to perform vitreo-retinal eye surgery, and its reach covers the major part of the vitreous cavity.
Abstract: Purpose:Developments in vitreo-retinal eye surgery are limited by human capabilities. To improve current vitreo-retinal surgical procedures and to enable new procedures, a robotic system has been developed, extending human capabilities. Methods:A compact, lightweight, easy to setup robotic master-slave system has been realized to perform vitreo-retinal eye surgery (Slave see Figure 1, Master see Figure 2). The system’s reach covers the major part of the vitreous cavity (up to the peripheral region). A combination of advanced mechanical and control design facilitates high accuracy (

Journal ArticleDOI
TL;DR: In this paper, a relation between different frequency response functions has been established and sufficient conditions for this relation to exist and results on uniqueness and equivalence of the HOSIDF and GFRF are provided.

Proceedings ArticleDOI
27 Jun 2012
TL;DR: A new representation of a teleoperation system is presented that allows to treat separately the mass, damping and stiffness of both environment and operator, allowing to put independent bounds on these parameters without introducing conservatism in the model.
Abstract: Bilateral teleoperation systems are used in different applications to manipulate the environment remotely. The control design for such systems represents a challenge in finding the proper balance in the inherent trade-off between transparency and stability. In order to address that problem, we present a new representation of a teleoperation system that allows to treat separately the mass, damping and stiffness of both environment and operator, allowing to put independent bounds on these parameters without introducing conservatism in the model. Moreover, we use robust control techniques based on Linear Matrix Inequalities theory to design controllers that guarantee performance and stability for a specific range of time varying environment and operator dynamics. Simulations demonstrate the effectiveness of the method to trade-off transparency and stability in a suitable way.