Rapid Prototype Development And Hardware In The Loop Simulation Of Electronic Parking System Controller

Parking brake system is a pivotal part of the vehicle brake system. Conventional parking brake system consists of metal cable and the lever which is maneuvered by drivers. While electronic parking brake system (EPB) produces parking brake force by an electromechanical actuator under control of a computer module. The intelligent electronic parking system has not only simple vehicle parking function, but also the ramp start function. The Hill-start function is beneficial to reduce drivers’the working pressure during the process of ramp start. In order to develop an electronic parking system with hill-start function, it is significant to research and develop a controller which can identify amount of brake force and quickly response to outside excitement.In this essay, based on various hardware and software kits such as MATLAB/Simulink, dSPACE ControlDesk, SimulationX and Code Warrior V5and so on, we build the physics and mathematics model, develop a set of fuzzy control algorithm according to the practical requirement of EPB, do the off-line simulation and hardware in the loop simulation of designed controller, and design a prototype controller with ds1005control board.The target vehicle’s driveline is also deeply analyzed in this essay, and its physics and mathematics model is built in Simscape. In order to verify the accuracy of driveline model, off-line simulation is done; furthermore, we compare the simulation results with the real vehicle operation characteristics and then adjust some key factors to guarantee the performance of driveline model is similar witch a real one. Finally, we develop the controller according to the characteristics of driveline system. To develop a high performance controller, the first important is to define a suitable control algorithm. We choose fuzzy algorithm as main control method in this essay. The procedure to design a fuzzy controller includes determining fuzzy control parameter, fuzzification of control parameters according to the range of signal, definition of membership functions based characteristics of each variable, design of fuzzy rules according to driving experience, and choosing suitable fuzzy inference method. In the following, we join the model of controller and driveline together and then do off-line simulation to verify the controller performance. After off-line simulation, hardware in the loop simulation is run based on dSPACE AutoBox. In order to make hardware in the loop simulation run smoothly, it is the most important to design and build a reliable hardware system. Hardware development includes designing a signal conditioning unit, making drive circuit, calibrating sensor and mounting the actuator to the hardware interface. Finally we convert the Simulink model into C language code and download them into the flash of control board by the realtime interface and real time workshop toolbox.Controller development and its hardware in the loop simulation mainly include two parts:first, the fuzzy controller to recognize driver intention based on Simulink is developed, including various work such as programming its code into the control board, connecting pedal signal and the clutch position signal to I/O board and doing hardware in the loop simulation to verify the function of fuzzy identification controller; second, the controller of actuator is designed, including the following work such as downloading program to the control board, monitoring the motor current and tension force on cable under a given excitation signal, and evaluating the performance of actuator controller. Through off-line simulation, hardware in the loop simulation and contrast experiments, the results show that the controller of EPB, which is developed in this essay, is feasible in the case of no engine characteristic map and no additional sensor.