Yoshiaki Araki

Active Suspension Control to Improve Ride Comfort at Any Specified Place

In this paper, a new active suspension control scheme is developed so that ride comfort at any specified place becomes best. To achieve this end, two ideal models are designed so that ride comfort becomes best at each different place. Then, linearly combining the two ideal models, a combined ideal model is proposed. It should be noted that by using only one design parameter, we can easily make ride comfort at a specified place become best in the proposed combined ideal model. To achieve the good property stated above in real vehicles, a robust tracking controller is proposed. It is shown by numerical simulations that ride comfort at a specified place can be easily improved in the closed loop system using the proposed combined ideal model.

A NEW STATE SPACE DESCRIPTION TO CONTROL ACTIVE SUSPENSION OF GROUND VEHICLES

SUMMARY In order to achieve good dynamic performances, ground vehicles must converge quickly to the equilibrium state which changes according to changes of coordinates of road surfaces. Though it is possible to make vehicles converge quickly to the equilibrium state if rigorous information of the changes of the equilibrium state can be obtained quickly, it is difficult generally to obtain the rigorous information. However, road surfaces can be recognized to have many waves with various frequencies. Thus good dynamic performances can be achieved without the information of the changes of the equilibrium state if control systems are designed so that suspension strokes respond along only high frequency waves of road surfaces. In this paper we propose a new state space description to design control systems in which suspension strokes respond along only high frequency waves.

Feedback Control Stability Analysis of Linear Slider Mechanism

Mechanical control can be made stable by taking into consideration mechanical resonance frequency and antiresonance frequency. A mechanical structure has different characteristics at each location at which force is applied and measuring location. The characteristics are different due to resonance frequency and antiresonance frequency. Antiresonance frequencies are determined by zero amplitude of dynamic behavior. Furthermore, their frequencies affect the control stability. This paper presents a method to distinguish between control stability and instability of the linear slider mechanism. In this method, control stability is distinguished to calculate the damping value of a multi-degree-of-freedom mechanism with control. Control algorithms are applied to positive acceleration feedback control and negative velocity feedback control.