Linear Preview Research Articles

Optimal Linear Preview Control of Active Vehicle Suspension

SUMMARY The problem of linear preview control of vehicle suspension is considered as a continuous time stochastic optimal control problem. In the proposed approach minimal a priori information about the road irregularities is assumed and measurement errors are taken into account. It is shown that estimation and control issues can be decoupled. The problem formulation and the analytical solution are given in a general form and hence they apply to other problems in which the system disturbances are unknown a priori, even in a stochastic sense, but some preview information is possible. The solution is applied to a two-degree-of-freedom (2-DOF) vehicle model. The effects of preview information on ride comfort, road holding, working space of the suspension and power requirements are examined in time and frequency domains. The results show that the greatest potential is for improving road holding properties. This effect could not have been observed in previous studies based on a 1-DOF vehicle model. It is also ...

Stability Criteria and Evaluation of Steering Maneuver in "Driver-Vehicle System".

Using a linear preview control model of a driver in lane-change maneuver, the stability criteria and performance index for the driver-vehicle system are derived analytically. In the stable area on the u-Tp : velocity, Tp : preview time) plane, the vehicle design parameters, rear wheel steering control algorithm and driver's characteristics can be discussed in terms of the measure for the good drive-feeling or possible safety criteria.

“Optimum Linear Preview Control With Application to Vehicle Suspension”—Revisited

Preview control of vehicle suspension as proposed by Bender is studied from the viewpoint of discrete optimal control. Improvements of the suspension system similar to those observed by Bender (reduction of acceleration and suspension clearance space) are rediscovered. The structure of the preview controller derived in this paper is clear, and is suited for practical use. The formulation and solution of a class of discrete optimal finite preview problems are given in a general form. Thus they apply not only to the suspension problem but also to other problems in which preview is possible. A comparison of Bender’s solution with the present solution is provided along with acceleration versus clearance space tradeoff information.

Optimum linear preview control with application to vehicle suspension-revisited

Optimum linear preview control with application to vehicle suspension-revisited

Optimum Linear Preview Control With Application to Vehicle Suspension

The concept of preview control (a control scheme in which an input is sensed before it reaches the controlled plant) is discussed and applied to the guidance of vehicles over statistically described surfaces. Two methods are presented for optimizing the trade-off between vehicle vibration and the clearance space required for excursions of a vehicle relative to a roadway. The first approach, based on Wiener filter theory, is used to synthesize the optimum characteristics (transfer function) of a free-configuration system. Since the transfer function synthesized in this manner is very difficult to mechanize, a parameter-search technique is used to optimize a fixed-configuration system which may be more easily realized in practice. The results of this study show the reduction in vibration and clearance space that a preview control system may bring about as compared to an optimized system that does not use preview information. Preview control may account for root-mean-square vibration reduction by as much as a factor of sixteen at constant clearance space or a decrease in clearance space by a factor of 223 at constant vibration level.