Journals
2002 International Journal of Control
Disturbance Response Decoupling and Achievable Performance with Application to Vehicle Active Suspension
Fu-Cheng Wang and Malcolm C. Smith
Abstract
This paper derives a structural condition on the controller for a given (stable) plant which guarantees that some prespecified closed-loop transfer function is the same as in the open loop. We also present conditions to test whether the achievable dynamic response of other transmission paths remains effectively the same if the controller is so restricted. The results are applied to simple quarter- and half-car vehicle models, and illustrated numerically for a double-wishbone half-car model.
2002 IEEE Transactions on Control Systems Technology
Controller Parameterization for Disturbance Response Decoupling: Application to Vehicle Active Suspension Control
Malcolm C. Smith and Fu-Cheng Wang
Abstract
This paper derives a parameterization of the set of all stabilizing controllers for a given plant which leaves some prespecified closed-loop transfer function fixed. This result is motivated by the need to independently shape several different disturbance transmission paths in vehicle active suspension control. The result is studied in the context of quarter-, half-, and full-car vehicle models, to derive appropriate controller structures. A controller design is carried out for the full-car case and simulated with a nonlinear vehicle dynamics model.
1993 IEEE Transactions on Industrial Electronics
A Fuzzy Scheduling Controller for a ComputerDisk File Track-Following Servo
Jia-Yush Yen, Fu-Jeng Wang and Yung-Yaw Chen
Abstract
In this paper, a fuzzy scheduling capability is superimposed on a computer disk drive track-following servocontroller to adjust for the plant variation as the actuator is locked onto different tracks on the disk. The fuzzy algorithm is used to best represent the complex relationship among the controllers for various tracks. Models of a Zentek 3100 disk drive actuator as it locks on a number of different tracks are experimentally identified to be the reference points. The design technique is then employed to obtain a robust optimal controller for each reference point. The actual controller for the disk drive actuator is then calculated using fuzzy interpolation. It is shown that with the controller scheduling action, the closed-loop performance is improved for the actuator at every track position. Error can be kept at a lower level than in the case where only a single controller is used.
Conference
2003 Proceedings of the 42th IEEE Conference on Decision and Control
Performance Benefits in Passive Vehicle Suspensions Employing Inerters
Malcolm Smith and Fu-Cheng Wang
Abstract
A new ideal mechanical one-port network element named the inerter was recently introduced, and shown to be realisable, with the property that the applied force is proportional to the relative acceleration across the element. This paper makes a comparative study of several simple passive suspension struts, each containing at most one damper and inerter as a preliminary investigation into the potential performance advantages of the element. Improved performance for several different measures in a quarter-car model is demonstrated here in comparison with a conventional passive suspension strut. A study of a full-car model is also undertaken where performance improvements are also shown in comparison to conventional passive suspension struts. A prototype inerter has been built and tested. Experimental results are presented which demonstrate a characteristic phase advance property which cannot be achieved with conventional passive struts consisting of springs and dampers only.
2001 Proceedings of the 40th IEEE Conference on Decision and Control
Controller Parameterization for Disturbance Response Decoupling: Application to Vehicle Active Suspension Control
Malcolm Smith and Fu-Cheng Wang
Abstract
This paper derives a parameterization of the set of all stabilizing controllers for a given plant which leaves some prespecified closed-loop transfer function fixed. This result is motivated by the need to independently shape several different disturbance transmission paths in vehicle active suspension control. The result is studied in the context of quarter-, half-, and full-car vehicle models, to derive appropriate controller structures. A controller design is carried out for the full-car case and simulated with a nonlinear vehicle dynamics model.
2001 Nonlinear and Adaptive Control Network (NACO 2), Workshop on Automotive Control
Active and Passive Suspension Control for Vehicle Dive and Squat
Fu-Cheng Wang and Malcolm C. Smith
Abstract
Performance capabilities of passive and active vehicle suspension systems will be examined from a mechanical networks point of view. It is known that the reduction of effects of road disturbances is a conflicting requirement with the reduction of effects of inertial loads in a quarter-car model when passive control is used, but not with active control of suitable structure. The extension of these ideas to a halfcar trailing-arm model will be considered. It will be shown that the choice of suspension geometry does not remove the basic trade-offs for passive suspensions. An active control structure to allow the road and load transmission paths to be optimised independently will be presented. The design approach will be applied to a non-linear trailing-arm vehicle model to demonstrate good anti-dive and anti-squat behaviour together with a soft ride in response to road disturbances. The performance of the controller will be demonstrated using the multi-body simulation code AutoSim.
1993 Second IEEE International Conference on Fuzzy Systems
A Fuzzy Scheduling Controller for the Computer Disk File Track-Following Servo
Jia-Yush Yen, Fu-Jeng Wang and Yung-Yaw Chen