Automobile Door Handle Sensor Test System Based on LabVIEW
May 09, 2022
Car Door Handles with smart entry system are used on many cars nowadays. Our factory develops door handles with keyless system for over 20 car models, such exterior door handle for hyundai and exterior door handle for nissan.
DHS (Door Handle Sensor) is a combination of a set of sensors that implement the identification function and send request signals in a car keyless entry system. To implement the intelligent door opening process, DHS needs to communicate with the remote key and the PASE ECU to identify the communication process. The DHS consists of a capacitive sensor (recognizing the human hand during the door opening process), a push button switch (closing action) and a low frequency antenna (and remote key communication). The working process of DHS is as follows. When the human hand approaches the door handle of the car, the capacitive sensor sends an inductive pulse to the PASE ECU. Then, the PASE ECU drives the low frequency antenna to send the request signal outward. The remote key receives the signal and responds to the PASE ECU in response to the identification of the RF signal. After the identification is completed, the PASE ECU controls the door to open automatically. The closing process is similar to the door opening process except that the button switch replaces the capacitive sensor to complete the door closing action. Similarly, closing actions also require identification.
The system is designed to meet the test requirements of the door handle sensor, and can perform antenna end impedance, Software Version, power supply current parameter, signal output and Go/No Go detection on the car door handle sensor. The system consists of PCI measurement, various bus instrument measurement and structure control system. The system frame diagram is shown in Figure 1.
The measurement system has the function of performing instrument control and signal measurement through a variety of buses. Mainly use the NI-DAQ data acquisition card PCI-6251 multi-channel analog input channel to collect and analyze the Software Version, power supply current parameter signal output, and measure the wireless antenna end impedance through the GPIB bus control LCR meter. The control system uses the NI digital IO card PCI-6514 to control the solenoid valve, plus the mature and reliable pneumatic components to complete the pneumatic control, and the safety circuit built by the industrial safety relay to monitor the pneumatic system. While the host computer software controls the digital IO to perform various mechanical actions, the safety circuit monitors the system switches and sensors, which can automatically cut off the system air source after the system is stopped or dangerously operated, ensuring that the pneumatic actuator is in a disabled state.
After the DHS test is completed, the PC software automatically runs different software processes based on the test results. For qualified products, the pneumatic structure automatically moves the sensor under test to the laser coder lens to complete the printing of the serial number of the product; for the unqualified product, the software program is locked, and only the operator throws the device under test into the waste bin. Carry out subsequent tests.
