Masao Kurimoto

Active suspension of passenger cars using linear and fuzzy-logic controls

Abstract This paper presents an active suspension system for passenger cars, using linear and fuzzy-logic controls. The model is described by a nonlinear system with four degrees of freedom, subject to irregular excitation from a road surface. The active control is the sum of two kinds of control. The former is obtained by vertical acceleration of the vehicle body as the principal source of control, and the latter is obtained by using fuzzy-logic control as the complementary control. In the derivation of fuzzy control rules, linear combinations of the vertical and rotary velocities and displacements of the vehicle body are denoted as the input variables. The simulation results indicate that the proposed active suspension system proves to be very effective in the vibration isolation of the vehicle body.

Construction of an active suspension system of a quarter car model using fuzzy reasoning based on single input rule modules

This paper presents the construction of an active suspension system for a quarter car model using fuzzy reasoning. The active control is obtained as a weighted sum of the defuzzificated values of the outputs in single input rule modules, and is generated by using a pneumatic actuator. The experimental result indicates that the proposed active control is more effective in the vibration isolation of the vehicle body than the skyhook damper and passive controls.

Active suspension system of a one-wheel car model using fuzzy reasoning and compensators

This paper is concerned with the construction of an active suspension for a one-wheel car model by using fuzzy reasoning. The experimental model is approximately described by a nonlinear system with two degrees of freedom subject to excitation from a road profile. The active control at the suspension location is designed by using fuzzy reasoning based on single input rule modules, and it is constructed by actuating a pneumatic actuator with dead time. The performance degradation of the active suspension system due to the dead time of the pneumatic actuator is improved by inserting two kinds of compensators. The experimental result shows that the active suspension system with the compensators more improves the control performance than that without compensator.

Active suspension system of one-wheel car models using the sliding mode control with VSS observer

This paper is concerned with the design of an active suspension system for one-wheel car models using the sliding mode control. The active control is derived as a sum of the LQ control and the nonlinear switching control where the LQ control is obtained by taking the acceleration of the car body seriously in the performance index. The active control force is obtained by using a pneumatic actuator, and the road profile is estimated by using the proposed simplified VSS observer. The experimental result indicates that the proposed active suspension system is more effective in the vibration isolation of the car body than the active suspension systems based on the LQ control and the skyhook damper control.

Active suspension design of one-wheel car models using an improved sliding mode control with the VSS observer

This paper is concerned with the active suspension design of one-wheel car models subject to excitation from a road profile using an improved sliding mode control with the variable structure system (VSS) observer. The active control is composed of the equivalent and the switching controls. The active control force for the suspension system is obtained by operating a pneumatic actuator due to the control signal that is generated by the measurement of the state variables, and the estimate of the excitation from the road profile. The experimental result indicates that the proposed active suspension system is relatively effective in the vibration suppression of the car model.

Construction of an active suspension for one-wheel car models using fuzzy reasoning and dual dynamic vibration absorbers

This paper is concerned with the construction of an active suspension for one-wheel car models using fuzzy reasoning and dual dynamic vibration absorbers. The one-wheel car model with the dual dynamic vibration absorbers attached to the wheel part is approximately described by a non-linear system with four degrees of freedom subject to excitation from a road profile. The main purpose of the dual dynamic vibration absorbers is to improve the road holding of the wheel over a wide range of frequencies. The active control is determined by fuzzy reasoning based on the single-input rule modules because the car model is expressed as a complicated system and the control force is constructed by actuating the pneumatic actuator. The experimental result indicates that the proposed active suspension is significantly effective for the road holding of the wheel and also for the vibration suppression of the car body and the wheel part.