Development Of Air-ABS-HIL-simulation Test Bench

Air-ABS -HIL-simulation test bench can accurately simulate the movements of the vehicle driving on all kinds of surfaces under different driving conditions.the air-ABS-HIL-simulation test bench which can shorten the time and the cost of developing ABS is a necessary tool to develop ABS quickly.This dissertation presents in detail the layout of the test bench and the working principle of the parts in the test bench. The air-ABS-HIL-simulation test bench is composed of a xPC target real time system that simulate the real vehicle,pressure sensors that measure the air pressure in chamber,direct current electromotors which rotate with rings to simulate the rotation of wheel,a ABS-controller-developping system(in the beginning ,it is a xPC target system which can develop control algorithm with Matllab/Simulink,in the end,it is a single chip developing system.),pressure enlarging circuit ,solenoid drive circuit and wheel signals precessing circuit in the ABS controller developing system act as a bridge to connect the software and the hardware in the test bench and make sure that the whole system can run in real time and form a closed control system.The air-ABS-HIL-simulation test bench is a very complicated system and is impossible to be finished one time. To build the test bench, it must be divided into several stagesThe first stage:ABS off-line simulation must be firstly done. Through the off-line simulation,the characters and the working principle could be deeply understand and mastered.the offline simulation program is composed of vehicle dynamics model,tire and wheel model,ABScontroller model,brake model and so on. The programm must be transformed into C codes and run in real time to check its real time capability. The program can provides the vehicle dynamics model and the tire and wheel model for the test bench.The second stage: seting up single-wheel-ABS-HIL-simulation test bench. ABS controller model and brake model ,tire wheel and vehicle model are merged into a computer. The wheel speed signal is directly sent to the ABS controller from the tire wheel and vehicle. Through building the sigle wheel test bench ,it can be known whether the xPC target real time system,the pressure seneor,the pressure enlarging circuit,the solenoid valve drive circuit,the software satisfy the requirementsThe third stage:a direct current electromotor a ring,a wheel speed sensor and a ABS controller are embedded into the sigle-wheel-ABS-HIL-silulation test bench.The fourth stage: baded on the sigle-wheel-ABS-HIL-silulation test bench, four–wheel-ABS-HIL-simulation test bench is build to develop the control ABS algorithm and ABS productIn this dissertation, the first stage and the second stage have been finished. using with the sigle-wheel-ABS-HIL-simulation test bench,ABS hardware-in–the–loop tests have been done.comparing the HIL results with the results of real vehicle ABS test results,their changing trend and shape are very similar that demonstrate the validility of results done by HIL test bench.