Principle Design And Experimental Verification Of A Test Bench For Simulation Of Vehicular Braking Of 1/4 Vehicle

Brake-by-wire systems,as one of the key components of the intelligent cars/unmanned vehicles,attract worldwide attention.The testing and evaluation technology have become the key step to the development of vehicular braking technology and further the intelligent cars/unmanned vehicles.How to simulate the road adhesion coefficient of different roads and to test and evaluate the performance of the vehicular braking systems is a subject worthy of study.A new principle of a test bench for real-time simulation of vehicular braking of 1/4 vehicle is studied.The test bench consists of a hardware system,including a motor,rollers,1/4 vehicle suspension system,a torque controller,a pair of flywheels,a signal acquisition and processing system,and a control system.The wheel speed and vehicle speed are simulated by the roller speed and flywheel speed,respectively.The translational kinetic energy of 1/4 vehicle is simulated by the rotational kinetic energy of the flywheels.The signal acquisition and processing system is used to acquire and process the signals,such as speeds and torques in the test bench.A magnetic powder clutch in the test bench is controlled by the control system to achieve the purpose of simulating the vehicular braking.Based on the principle of test bench and the theory of vehicle dynamics,a prototype system of test bench is built.The simulation method of the translational kinetic energy of 1/4 vehicle is investigated.The mathematical models of the real-time simulation about road adhesion coefficient based on the magnetic powder clutch with controllable transfer torque are established.Based on the established models,the simulation results are compared and analyzed,under various road conditions.Finally,preliminary tests are carried out to verify the feasibility and effectiveness of the test bench to simulate the changing road adhesion coefficient.