Research Of ABS Performance Testing System

The vehicle industry is through adevelopment of many centuries,and gradually perfect,particulary is along with technical development in modern electronics of vehicles,the electronics equipments of vehicles also complicates gradully.Along with the ecomonic development and live horizon exaltation,the vehiclea have already entered common people famliy as enduring consumer goods in large quantity,and from here the traffic accident that caused also increased rapidly ,it resulted in bigness the bane to people's life and property.People also more and more value the vehicle safety ,every kind of the electronics equipments related with the vehicles safety have been constantly developed,the anti-lock braking system (ABS) is one of them.ABS can exert the brake power of the vehicle braking system to the best but keep the wheel from locking, which farthest guaranteed the vehicle's stability during braking ,shorten the brake distance and brake time,ensured the vehicle safety.It is a closed-loop braking system,is the most outstanding achievement of electronics control tecnique applied in vehicle.Along with ABS widely applicantion,the need of detection and diagnosis for ABS has continuousily increased.But the current extant test-bed for ABS is too expensive or too cokamamie to be applied by the best-lines and garages.So our research team developed the new type test-bed for ABS,which can accurately and fleetly find fault in the mechanical can electric part of ABS in room.This paper is divided into four parts on vehicle performance test-bed:ABS.The first part mostly introduces the principle and structure of the ABS test. For the one thing, it introduces the basic principles, the composing and working principle of the ABS. The ABS test-bed designed base on above principles .The test-bed mainly consists of the electrical engine,the magnetic particle clutch, the flywheel, the main tumbling box, the auxiliary tumbling box, the speedy sensors, the torque sensors, the computer controlled systems and the showing system of the test results. The working principle is the main tumbling box running by the motor-driven, the main tumbling box drive the running of the cartwheel, and the cartwheel drive the running of the auxiliary tumbling box again. The speed of the main tumbling box equivalent to the bodywork's, the auxiliary tumbling box and the cartwheel running at the same rate. When the cartwheels turned up to theappointed speed at Vо, pedal the brake pedal to implement brake, the ABS car then started working. Braking time and the braking distance and the change of slippage rate are the key guide lines for measuring the performance of ABS. In order to obtain data for these guide lines, this test-bed had installed speed sensor in the main and auxiliary tumbling box. The speed changes of the main and auxiliary tumbling box can be measured by the speed sensors. Thereout the slippage rate of the braking process can be counted and the speed changing curve can be protracted. The role of magnetic particle clutch is simulated road's adhesion coefficient. By changing the magnetic particle clutch in the torque output of the excitation current control, and then simulated different road's adhesion coefficient. In the process of braking, the motor non-stop turns, and follow the definite law to continue rotation, the aim is simulation the inertia of vehicle movement. Computer controlling system real-timely adjust the motor rotate speed and the output torque of the magnetic particle clutch based on the feedback signal of the speed and torque sensors.The second part mostly introduces the hardware and software of the system. Some of the hardware systems mainly include the design of the sensor's signal processing circuit, namely V/I transform circuit, isolation amplifying circuit and A/D transform circuit. Due to influence of the strong electromagnetic interference by the industry spot, the sensor itself, and the amplifying circuit, the sensor's signal transit by the cable transmission, arriving the measuring system, often contain multiple elements of the noise frequency interference signals. In serious cases, such the noise signal will take away from input signal that wait for picking-up, resulting in the system unable to obtain the measured signal. To eliminate and restrain the interferential signal that consisted in the measuring and controlling system, we design the hardware and software from the perspective of the anti-jamming capability.The software of the system designed according to the system, the program adopted modularization. That of any logical part of a program block can be changed without affecting any other part of the program. Each block can process as a subroutine call for other procedures. The whole software of automatic test system is buildup with the data acquisition module, energy compensation module, rendering the speed variation curve of the wheel and body modules, rendering the slippage rate curve module.The third component is the study and realization of the manipulative arithmetic. The key of test-bed is how to simulate the translational inertia when applythe brake in real-road. This paper introduces two arithmetic of analog control. The hybrid control algorithm and simulation technology -- mechanical inertia simulation algorithm. However, these two algorithms are not satisfactory; I improved the arithmetic on the basis of mechanical inertia simulation algorithm. And then control the magnetic particle clutch to simulate the road's adhesion coefficient by the controlled silicon controlled. Control the electrical motor real-timely via the double closed-loop manipulative system. Imitating with"Matlab", receive a more perfect outcome.The fourth component is the data processing. Computer Measurement of the signal generally contains the errors, how to remove these errors from the measured values. How to minimize the error that measurement results contain is a common data-processing problem. In this parts, primary introduced the least square method in curve fitting to proofread systematic error. Also introduced FIR filter and used Hamming designed a low pass to complete the filter errors. Systems debug and demarcate also be done on ABS monitoring system. In the end of the paper, summarize the full text, and bring forward the expectation to the later work.This subject completed basis of the theoretical, combine with the experiments in the laboratory and in field tests. Mathematical model's derivation and theoretical methods'discussing as well as the process of practical control system design. This paper describes the design of the control system, with ABS performance measurement accuracy, reliability, real-time performance and robustness. In practical application has been made very good results. This design has a very important practical value to ABS on the development of performance measurement and testing equipment. It can generate enormous economic and social benefit, so this subject has a great theoretical and practical significance.