Research And Design Of Automatic Control System For Wheel Bending Fatigue Testing Machine Based On Magnetic Moment

Wheels are of critical importance to the operation of a car.With the development of automotive technology,requirements have become more stringent on wheel performance.Therefore,the bending fatigue wheel test is highly important and must be conducted prior to the testing of new designs of wheels and the wheel loading sample testing.Currently,the bending fatigue wheel test is mainly based on GB / T 5334-2005 "passenger car wheel performance requirements and test methods".However,the current device used for wheel bending fatigue testing requires,firstly,calculation of the test bending moment and estimation of eccentric distance and turning velocity according to specimen model and parameters.It further relies on manual determination of eccentric block weight and adjustment of the eccentricity.This kind of test equipment has problems of a long test preparation time,too much manual participation,complex manipulation,errors in test results,single test spectrum and so on.Based on magnetic moment,this paper designs an automatic control system in wheel bending fatigue testing machine.The new solution is created in response to the needs and application status of domestic wheel and automobile manufacturers.This paper introduces the designs of main hardware structures of the wheel bending fatigue testing machine,and software automatic control system.In the design of the machine's load-loaded arm of the hardware,the bending moment is generated through a set of designed electromagnet devices,which produce the magnetic force from spins combined with the self-weight from the magnet.The advantage of this device is to achieve the effective control of values of the wheel torque by monitoring the electric current from the electromagnet,and to improve the degree of the automation and test efficiencies,and minimize errors of the bending fatigue wheel test.Meanwhile,the designed device can easily control the electric current of the electromagnet to change the torque value,and achieve diverse results of spectrum tests.For the design of the controlling system,the machine applies the cooperative method between upper and lower machines.The lower machine uses the programmable regulator-PLC-for data acquisition and motion control while the upper machine adopts the virtual instrument-LabVIEW-as the interface for operations.The upper and the lower machines are connected by RS485 which is a device for communication.The LabVIEW is the test machine's major interface which is for displaying,controlling and recording data for the bending moment and loading arm displacement during the process of the tests.The machine relies on the output of sine wave,square wave and triangular wave from the loading wave spectrum module to achieve different test results.The machine can measure the offset of the arm to determine if the wheel fails,and alert before the wheel fatigue.LabVIEW,as an operational platform,provides the test with detailed results,control panels and data storage spaces.