Performance evaluation of antilock brake controller for pneumatic brake system

Antilock brake system (ABS), equipped in a vehicle, increases safety because it prevents wheels from being locked up and minimizes the danger of skidding, allowing the vehicle to stop in a straight line. ABS also allows drivers to maintain steering control of a vehicle during emergency braking of it. So the vehicle can avoid obstacles or another vehicles on the road. This paper deals with an antilock brake controller for full-air brake system, which is widely used in heavy vehicles such as buses and trucks. Two methods of evaluating the ABS controller and the algorithms were focused on: laboratorial test and field test. For the laboratorial test, a hardware in-the-loop simulator (HILS) was made. This includes actual pneumatic brake hardware between the controller input and vehicle dynamics output, thus simulating a whole bus under braking in real time. This paper describes how the HILS of antilock brake system of a bus was constructed, and how this HILS can be used for evaluating the antilock brake algorithms and electronic control unit (ECU) in the laboratory. Using HILS, we could achieve functional tests needed in an ABS controller in a short time. As a result we could reduce time and cost needed for developing the controller for pneumatic brake. For the field test, a bus equipped with an ABS controller was driven and stopped in the test field, where severe road conditions exist. This paper also describes configurations of the data acquisition system for it. Finally we compared the results of the laboratorial HILS tests with those field tests and proved the HILS is a good method for developing a new system, especially in automotive applications.