Design And Research Of Detection System For Drag Torque Of Automobile Brake Caliper

Drag torque as an important indicator of brake caliper,if its value is too large,it can increase fuel consumption,damaged parts,and easy to cause the lock.At present,the drag torque is detected by artificial oiling with low degree of automation in the lab of companies,the acceleration time of brake caliper is not controlled,and the detection data is not compare with the gas inspection mode.In view of the above problems,based on industry standards and company needs,lead into incremental PID control algorithm,design a drag torque detection system,it can oiling automatically and so on,and compare with gas inspection methods.The research mainly includes:(1)According to the industry standard QC/T 592-2013 and the needs of the companies,analyze the detection system’s requirements,determine the precision of sensor,hydraulic test,drag torque measurement range and other technical indicators,and based on the above analysis,design the detection system’s measurement and control pipeline,use the PCI data acquisition card and motion control card to design the hardware circuit.(2)According to the functional requirements of the detection system,using LabView to design the software based on the idea of multithreading and modularization,it realizes automatic operation such as automatic oiling,dragging torque detection,high hydraulic seal detection and so on.And it has the functions of parameter configuration,motion control,data acquisition,data management and so on.(3)Using incremental PID to control the brake caliper,shortening the speed of acceleration,and when the test speed is 45r/min,the acceleration time of the brake caliper is shortened by 0.14 s,which improves the accuracy of dragging moment detection and stability of the system.The algorithm is simulated by Matlab/Simulink software,which provides theoretical support for the algorithm.(4)Selecting a manufacturer’s type brake caliper and test it,analyzing the stability of the system and comparing with the test results of the gas test and the principle of pressure,it is concluded that the pressure of the liquid test is more stable and the result is more accurate.Finally,the uncertainty of measurement are calculated.The uncertainty of the first cycle and the tenth circle drag torque is 0104N·m and 0.098N·m,which meet the requirements of the system detection.