Development and Verification of Electronic Braking System ECU Software for Commercial Vehicle

Electronic braking system (EBS) of commercial vehicle is developed from ABS to enhance the brake performance. Based on the early development of controller hardware, this paper starts with an analysis of the definition of EBS. It aims at the software design of electronic control unit, and makes it compiled into the controller in the form of C language by the in-depth study about control strategy of EBS in different braking conditions. Designed controller software is divided into two layers. The upper control strategy includes the recognition algorithm of driver's braking intention, estimation algorithm of the vehicle state, conventional braking strategy which consists of the algorithm of deceleration control and braking force distribution, and emergency braking strategy which consists of the algorithm of brake assist control and ABS control. Lower control strategy includes feed-forward compensation and PID control of proportional relay valve, on-off control of axle modulator, on-off control of axle modulator of ABS solenoid valve and the design of CAN communication. Based on the hardware-in-the-loop simulation test-bed, this paper conducts EBS hardware-in-the-loop simulation tests in different conditions. The test conditions consist of loaded conventional brake, unloaded conventional brake, loaded emergency brake, unloaded emergency brake. The test results show that the control strategy in different conditions can achieve the expected result. Experimental work confirms that the designed software can be used as the basis of the product development.