Application of LabVIEW in the production of wiper motors for Volkswagen Bora A4 cars

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Application of LabVIEW in the production of wiper motors for Volkswagen Bora A4 cars [Copy link]

The wiper motor of the Bora A4 produced by Volkswagen is a permanent magnet DC motor with an operating voltage of 13V and a rated output power of 40W. The motor leads are 4-wire, including high-speed end, low-speed end, reset end and ground end. The wiper motor has a reduction gearbox with a switch inside. When the reset end is connected to a 13VDC voltage, the motor will first rotate slowly. When the worm wheel convex point reaches the reset point, the reset switch in the reduction gearbox is closed, the motor armature is short-circuited, the motor is braked by energy consumption, and the wiper is reset. At the same time, the power supply is disconnected.

According to the technical requirements of the project, it is necessary to test the high and low speeds, high and low speed differences, high and low speed currents, voltages, and motor reset angles of the motor under certain load conditions, and stop the motor at the "loading angle". In addition, it is also necessary to test the vibration of the motor under no-load conditions.

Choice of development software

After analyzing and comparing several excellent industrial control software in the world, the foreign technical staff of Valeo suggested that Shanghai Valeo Automotive Motor Wiper System Co., Ltd. use LabVIEW software to develop and manufacture special equipment, and they believed that "LabVIEW software is the best." Based on the actual use of the production equipment of Shanghai Valeo Automotive Motor Wiper System Co., Ltd., the engineers conducted demonstrations among LabVIEW, VB and other industrial control software, and finally chose LabVIEW software.

The main reason they chose LabVIEW software is that it is easy to learn, has a user-friendly interface, powerful functions, stable performance, and a short development cycle. In addition, since Shanghai Valeo Automotive Motor Wiper System Co., Ltd. previously used LabVIEW software to develop imported equipment, it provided LabVIEW software training to relevant engineers, so the engineers are familiar with the LabVIEW software system.

Select Board

The project requires 4 analog inputs, 2 analog outputs, 2 counters, 7 digital inputs, and 12 digital outputs. The NI analog acquisition card PCI-6024 board was selected, which has 8 differential analog inputs, 2 analog outputs, a sampling rate of 200KS/s, 12 bits, 2 counters, and 8 digital I/O ports.
The other board is the digital acquisition card PCI-6503: it has 24 I/O ports.

Overall Design

The engineers first opened several text files in the C drive, which contained the upper and lower limits of motor performance parameters such as voltage, current, speed, etc.; the upper and lower limits of motor vibration parameters; the calibration coefficient of the vibration sensor; the nonlinear calibration coefficient of the magnetic powder brake, etc. Each time the program is run, the data in the above text files is read first as the indicators and test coefficients for judging the quality of the motor. The advantage of doing this is that these key parameters can only be modified by the relevant engineers, and the operators cannot modify them, avoiding human test errors. (The motor test interface is shown in Figure 1.)

Figure 1 Motor performance and vibration test interface