Four-wheel steering vehicle based on the model of control

Four-wheel steering vehicle to improve vehicle stability as an effective means has been widely recognized, many new point of view on four-wheel steering has been continuously raised, the use of 4WS technology can effectively reduce the low speed when the vehicle's turning radius, the vehicle be more flexible at low speeds. Meanwhile, the technology can also improve the vehicle at high speed and yaw rate and lateral acceleration transient response indicators, improve the handling and stability at high speeds, thereby enhancing the vehicle's active safety. In order to meet the requirements of experimental research, the subject suggests, 1 / 10 model four-wheel steering vehicle based test system to build, on this basis, rear wheel steering controller design and conduct tests. Increase in the model vehicle by rear-wheel steering to achieve four-wheel steering function steering optimized design to meet Ackermann theorem. In order to achieve data acquisition, model vehicles equipped with acceleration sensors, angular rate sensor, speed sensor and wireless transmission module. Acceleration sensors and angular rate sensors are used to measure the sideslip angle and yaw rate. Wireless module for transmitting the sensor data and control data acquisition. In this four-wheel steering system on the basis of experimental design the optimal controller to control the steering wheel to minimize the sideslip angle, yaw rate response is consistent with the front wheel steering vehicle. Controller is the main data collection by the AVR MCU board, the wireless module to transmit the collected data to PC host computer Kalman filter and optimal feedback gain matrix calculation, the results recorded by the wireless module operator transmitted to the actuator board AVR microcontroller, and drive the rear wheel steering servo motor to achieve. Finally, four-wheel steering on the test system to test, compare two performance steering and four-wheel steering. Proved in the same conditions, with optimal control than the traditional two-wheel steering vehicle better performance steering vehicles, the sideslip angle tends to zero, while the yaw rate response remained the same. 

Keywords: model cars, four wheel steering, steering mechanism, 4WS controller, Kalman filtering, optimal control