This paper presents a mathematical vehicle model that is designed to analyse and improve the dynamic performance of a vehicle. A wheel slip controller for anti-lock braking system (ABS) brakes is formulated using a sliding mode controller and a proportional-integral-derivative (PID) controller for rear wheel steering is also designed to enhance the stability, steerability, and driveability of the vehicle during transient manoeuvres. The braking and steering performances of controllers are evaluated for various driving conditions, such as straight and J-turn manoeuvres. The simulation results show that the proposed full car model is sufficient to predict vehicle responses accurately. The developed ABS reduces the stopping distance and increases the longitudinal and lateral stability of both two-and four-wheel steering vehicles. The results also demonstrate that the use of a rear wheel controller as a yaw motion controller can increase its lateral stability and reduce the slip angle at high speeds.

In this study, a new column-type electric power steering (EPS-TT) system is investigated. The remarkable features of this EPS-TT system are its opto-isolated torque sensor, which is used to make steering torque measurements, and its assist torque control methodology, which uses a unidirectional motor and two clutches. Thus it does not require a complicated motor drive system that consumes a large amount of electrical energy when the direction of rotation is reversed. This allows the new system to use a smaller and simpler assist motor. A full steering system model and a simplified model are developed to evaluate the EPS-TT system. A full car model is also used to investigate the vehicle response. A map-based control method and a proportional-integral-derivative control algorithm are designed to control the EPS-TT system. Various sinusoidal inputs are applied to the system and the resulting performance is analysed. The results show that the performance achieved by the EPS-TT system is similar to that of a conventional EPS system across the frequency domain. The results for the full steering system model are similar to those for the simplified model, but the vehicle response is slightly different. The map-based controller provided good performance without affecting the stability or controllability of the vehicle.

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This study evaluates traction control systems (TCSs) composed of either a wheel slip controller or a throttle valve controller, or an integrated controller of both systems. The dynamic characteristics of a vehicle and a TCS are evaluated using a proposed full car model that can simulate the responses of both front-wheel-drive and four-wheel-drive vehicles. A driver model is also modified to control the vehicle during tests on a road with split Coefficients. The results show that the brake TCS provides more acceleration on uniform slippery and split roads, but the yaw rate and the lateral off set are larger than those obtained when an engine TCS is used. When the vehicle is cornering and accelerating with the brake or engine TCS, understeer or oversteer occur, depending on the driving conditions. An integrated TCS prevents most of these problems and improved the stability and controllability of the vehicle. Four-wheel-drive vehicles exhibit better traction control than two-wheel-drive vehicles, but their steerability is reduced.

This paper describes an experimental study into the vibration control of a servo system comprising a servo motor and a flexible manipulator. Two modes of the system are controlled by using the servo motor and an accelerometer attached to the tip of the flexible manipulator. The control system is thus non-collocated. It consists of two electrical dynamic absorbers, each of which consists of a modal filter and, in case of an out-of-phase mode, a phase inverter. The experimental results show that each absorber acts as a mechanical dynamic vibration absorber attached to each mode and significantly reduces the settling time for the system response to a step input.