The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Tarunraj Singh - One of the best experts on this subject based on the ideXlab platform.
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Pole-Zero, Zero-Pole Canceling Input Shapers
Journal of Dynamic Systems Measurement and Control, 2011Co-Authors: Tarunraj SinghAbstract:This paper presents the development of an input-shaper/Time-delay filter, which exploits knowledge of the zeros of a minimum-phase transfer function to reduce the output-transition Time for a rest-to-rest Maneuver problem, compared to the traditional zero vibration (ZV) input shaper. The Maneuver Time of the robust input shaper presented in this work will correspondingly have a smaller Maneuver Time compared to the zero vibration derivative (ZVD) input-shaper. The shaped profile is changing with Time even after the completion of the Maneuver similar to postactuation controllers. All the traditional technique for addressing multiple modes and desensitizing the filter over a specified domain of uncertainties are applicable to the technique presented in this paper.
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CDC - Sequential linear programming for design of Time-optimal controllers
2007 46th IEEE Conference on Decision and Control, 2007Co-Authors: Tarunraj Singh, Puneet SinglaAbstract:This paper presents a sequential linear programming approach for the determination of Time-optimal controller for nonlinear systems. The sequential linear programming solution is used to update the control profile so as to satisfy the terminal conditions for an assumed Maneuver Time. A univariant minimization approach which brackets the optimal value of the Maneuver Time, such as the bisection algorithm is used in an outer loop to converge to the minimum Time. The proposed technique is illustrated on two benchmark problems: the attitude control of a spacecraft and the minimum Time control of a robot.
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Controller Design for Flexible Systems With Friction: Pulse
2005Co-Authors: Jae Jun Kim, Tarunraj SinghAbstract:Friction is highly nonlinear in the low-velocity region and when there is a velocity reversal. For precise positioning and pointing systems, difficulty in control arises near the desired final position because of stiction. Conventional PD and PID controllers are known to cause steady-state error and hunting 1. Yang and Tomizuka 2 developed the adaptive pulse width control technique for rigid body systems. The pulse width control can avoid the problems of hunting and velocity reversals by allowing the system to coast toward the desired position. To account for imperfect knowledge of the system parameters which result in terminal state errors, successive pulses are applied until the desired position is reached. An unknown parameter that is a function of friction and inertia is adapted, which is subsequently used to calculate the pulse width. With the static and Coulomb friction model used in Ref. 2, the friction force is considered constant because the proposed technique guarantees unidirectional motion of the system. Rathbun 3 extended the pulse width control to a flexible two mass spring damper system. He used the single pulse to study the stability bounds on the pulse widths. Although the controller is stable, the flexible mode excited by the input pulse will result in undesirable residual vibration. If the damping is small, the settling Time will increase, which will increase the Maneuver Time. Singh and Vadali 4,5 developed Time-delay filtering techniques to preshape reference inputs, which result in the elimination of residual vibration of the flexible systems. This involves design of a prefilter that cancels the underdamped poles of the system. Robustness to variations in frequency and damping is achieved by placing additional zeros of the Time-delay filter at the expected location of the complex poles of the system. This technique was further applied to systems with limited actuator bandwidth by imposing a constraint on the Time rate of change of the control input 6. However, the Time-delay filtering technique can only be used for linear systems. Although the friction phenomena exhibits a hard nonlinearity near-zero velocity, the friction force will act as a bias input force to the linear system, if the velocity does not change signs during the Maneuver. With this friction biased input, techniques for the design of control profiles for linear systems can be exploited. Kim and Singh 7 applied linear programming to find the control profiles of the system with the friction biased input force. The positive velocity constraints of the frictional body is imposed in addition to the boundary conditions and control input bounds in the design of the controller. The control profile resulting from the linear programming shows that stiction occurs during the Maneuver for small command displacements. Therefore, friction force cannot be considered constant during stiction. In this paper, a three pulse control profile is first proposed with user-selected pulse width. The pole-zero cancellation technique in conjunction with an iterative method of solving this problem is presented. This is followed by studying the restriction on the control input to maintain positive velocity of the first mass. If stiction occurs during the Maneuver, the control profile has to be modified, as illustrated in Sec. 7. Numerical simulations are performed to verify the proposed controllers.
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Concurrent Feedback/Feedforward Design for Second Order Systems
Scopus, 2005Co-Authors: Jayaram Gopalakrishnan, K. V. Umamaheswara Reddy, Tarunraj SinghAbstract:This paper studies the problem of concur- rent design of a feedback controller and a pre-filter to minimize a weighted cost comprising the Maneuver Time and the input power. The pre-filter is parameterized as a Time-delay filter motivated by the Posicast controller. The proposed technique is illustrated on a double integrator assuming that the feedback controller is of the proportional derivative form. A closed form expression relating the weighting parameter and the number of delays, to the feedback gains is derived. The proposed technique is also illustrated on spring-mass and spring- mass-dashpot systems.
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Fuel/Time Optimal Control of Flexible Space Structures: A Frequency Domain Approach
Journal of Vibration and Control, 1999Co-Authors: Rolf Hartmann, Tarunraj SinghAbstract:This paper considers the design of open-loop fuel/Time optimal controllers for flexible space struc tures using a frequency domain approach. The control system consists of a Time-delay filter whose output signal is the optimal control profile when it is subject to a step input. A constrained parameter optimization problem is formulated to minimize a weighted combination of fuel consumed and total Maneuver Time for a rest-to-rest Maneuver. The parameters to be optimized for are the delays of a Time-delay filter. The number of switches of the fuel/Time optimal control profile is shown to be a function not only of number of flexible modes but also of the weighting parameter, which is illustrated via numerical examples.
Junjiro Onoda - One of the best experts on this subject based on the ideXlab platform.
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Two-stage strategy for simultaneous slewing and vibration suppression of flexible structures
Computer Methods in Applied Mechanics and Engineering, 1997Co-Authors: Xiaojian Liu, Junjiro OnodaAbstract:Abstract This paper presents an open loop near-minimum-Time solution for simultaneous slewing and vibration suppression of flexible structures. The problem is formulated as an open-loop, minimum-system energy and/or control effort optimal control problem in modal space. With parametric control law, a two-level problem-solving strategy is presented. In the first stage, a sequence of rigid mode-based Time-optimal control problems is solved and the minimum Maneuver Time is found by gradually reducing the Maneuver Time until the solution converges. In the second stage, the optimal parameters of the control law are evaluated using nonlinear programming with prescribed performance index as its objective function. The proposed strategy, through Time-optimal control of the rigid mode combined with the parametric quadratic control of the clastic modes, determines the control profiles which give both minimum Maneuver Time and desired value of performance index. As an example, the optimal control of a slewing flexible beam is presented, and high performance slewing Maneuver is achieved.
Puneet Singla - One of the best experts on this subject based on the ideXlab platform.
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CDC - Sequential linear programming for design of Time-optimal controllers
2007 46th IEEE Conference on Decision and Control, 2007Co-Authors: Tarunraj Singh, Puneet SinglaAbstract:This paper presents a sequential linear programming approach for the determination of Time-optimal controller for nonlinear systems. The sequential linear programming solution is used to update the control profile so as to satisfy the terminal conditions for an assumed Maneuver Time. A univariant minimization approach which brackets the optimal value of the Maneuver Time, such as the bisection algorithm is used in an outer loop to converge to the minimum Time. The proposed technique is illustrated on two benchmark problems: the attitude control of a spacecraft and the minimum Time control of a robot.
Xiaojian Liu - One of the best experts on this subject based on the ideXlab platform.
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Two-stage strategy for simultaneous slewing and vibration suppression of flexible structures
Computer Methods in Applied Mechanics and Engineering, 1997Co-Authors: Xiaojian Liu, Junjiro OnodaAbstract:Abstract This paper presents an open loop near-minimum-Time solution for simultaneous slewing and vibration suppression of flexible structures. The problem is formulated as an open-loop, minimum-system energy and/or control effort optimal control problem in modal space. With parametric control law, a two-level problem-solving strategy is presented. In the first stage, a sequence of rigid mode-based Time-optimal control problems is solved and the minimum Maneuver Time is found by gradually reducing the Maneuver Time until the solution converges. In the second stage, the optimal parameters of the control law are evaluated using nonlinear programming with prescribed performance index as its objective function. The proposed strategy, through Time-optimal control of the rigid mode combined with the parametric quadratic control of the clastic modes, determines the control profiles which give both minimum Maneuver Time and desired value of performance index. As an example, the optimal control of a slewing flexible beam is presented, and high performance slewing Maneuver is achieved.
Nansheng Pang - One of the best experts on this subject based on the ideXlab platform.
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application of genetic annealing algorithm in multi resource balanced optimization considering Maneuver Time
Electronic and Mechanical Engineering and Information Technology, 2011Co-Authors: Hui Huang, Siyu Bai, Nansheng PangAbstract:The traditional research of resource balanced optimization is based on the uniform distribution of resources and the sacrifice of Maneuver Time. However, in the actual construction, resources have diversity and the emergent events always exist. So to take account of the diversity of resources and be given some Maneuver Time to deal with these emergencies is necessary. Based on the analysis of the resource balanced optimization, this paper increased Maneuver Time as one of the optimization goals in objective function, to construct a balanced optimization model of multi-resource allocation. In addition, a numerical example is given to demonstrate the better effectiveness and practicality of this model.
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EMEIT - Application of genetic annealing algorithm in multi-resource balanced optimization considering Maneuver Time
Proceedings of 2011 International Conference on Electronic & Mechanical Engineering and Information Technology, 2011Co-Authors: Hui Huang, Siyu Bai, Nansheng PangAbstract:The traditional research of resource balanced optimization is based on the uniform distribution of resources and the sacrifice of Maneuver Time. However, in the actual construction, resources have diversity and the emergent events always exist. So to take account of the diversity of resources and be given some Maneuver Time to deal with these emergencies is necessary. Based on the analysis of the resource balanced optimization, this paper increased Maneuver Time as one of the optimization goals in objective function, to construct a balanced optimization model of multi-resource allocation. In addition, a numerical example is given to demonstrate the better effectiveness and practicality of this model.