Earticle

Modern day vehicles can hardly mobilize without the electronic control unit (ECU) – the CPU that controls every embedded system of the vehicle. One of the core system of ECU is the electronic stability program (ESP). It intervenes the driving by controlling the engine and the brake when the vehicle is in discord with the original intention of the driver. Current models of ESP set various modes that differentiate the activation rate of the ESP. Yet, several problems exist, as drivers have to manually alter the modes that match an immutable activation rate. Therefore, this thesis introduces a new ESP algorithm that automatically sets the activation rate. Artificial neural network (ANN) is employed, and experiment is designed to train this ANN algorithm with imaginary inputs. Successful results of customizing ESP will prove the possibility of applying artificial intelligence to the rest of the functions of ECU and thereby fully customizing the ECU.

The vehicle dynamic control system needs to detect the yaw rate of vehicle and a yaw rate sensor is required as a central component. Therefore, A sensor on the basic of the "tuning fork method" for automotive controls is being developed. The sensor was fabricated by the surface micro machining process to miniaturize its size. The sensor output offset is ${\pm}0.37^{\circ}/sec$ in the room temperature. The resonance frequency of the fabricated yaw rate sensor is measured to 5.29kHz for the drive mode. Tests of the sensor demonstrate that its performance is equivalent to that required for implementation of a yaw control system. Vehicle handling and safety are substantially improved using the sensor to implement yaw control.

This paper describes the control philosophy of ESP(Electronic Stability Program) which consists of the stability control the fault diagnosis and the fault tolerant control. Besides the functional performance of the stability control, robustness of control and fault diagnosis is focused to avoid the unnecessary activation of the controller. The look-up tables are mentioned to have the accurate target yaw rate of the vehicle and obtained from vehicle tests for the whole operation range of the steering wheel angle and the vehicle speed. The wheel slip control with a design goal of wheel slip invariance is implemented for the yaw compensation and the target wheel slip is determined by difference between the target yaw rate and actual yaw rate. Since the ESP has a high severity level and the robust control is required, the robustness margin for the stability control is determined according to several uncertainties and the robust fault diagnosis is performed. Both computer simulation and test results are shown in this paper.

This paper presents a method for designing a controller that uses an active anti-roll bar (AARB) and an electronic stability program (ESP) for rollover prevention. ESP with longitudinal speed control (LSC) can carry out active braking to reduce vehicle speed and lateral acceleration to prevent a rollover. To enhance the rollover prevention capability of the ESP, an AARB is adopted. The controller for the AARB was designed based on linear quadratic (LQ) static output feedback (SOF) control methodology, which attenuates the effect of lateral acceleration on the roll angle and roll rate by control of the suspension stroke and the tire deflection of the vehicle. Although this AARB significantly increases ride comfort and rollover prevention, it has a drawback-the vehicle loses its maneuverability. Therefore, the ESP with LSC is used to overcome this drawback. Simulations showed that the proposed method was effective in preventing a rollover.