Limited angle motor test system

Abstract

A limited angle motor test system comprises a measurement and control computer, a test voltage circuit, a test resistance circuit and a power supply, test instructions are respectively sent to the test voltage circuit and the test resistance circuit through measurement and control calculation, and unlocking time and reset time of a limited angle motor are tested by controlling the test voltage circuit. The resistance of the limited angle motor is tested through the test resistance circuit, and then data is transmitted to the measurement and control computer, so that automatic test of unlocking time, reset time and resistance parameters of the limited angle motor is realized, manual calculation is not needed, and the test precision and efficiency are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor testing, in particular to a limited rotation angle motor testing system. BACKGROUND

[0002] When the limited rotation angle motor is powered on, the motor rotor rotates from the safe position to the unlocking position, and after power off, the rotor is pulled back to the safe position by the reset spring. In order to ensure the action reliability, control accuracy and response speed of the motor in actual application, it is necessary to comprehensively test its multiple performance indicators in the production detection stage, including unlocking time, reset time, unlocking position contact resistance, safe position contact resistance, etc.

[0003] The performance test of the limited rotation angle motor mainly relies on manual operation and cooperation of multiple instruments. Generally, an oscilloscope is used to collect the voltage signal waveform diagram of the motor when powered on and powered off, the time difference between the rising edge and the falling edge of the waveform is observed, and the unlocking time and the reset time of the motor are manually calculated. Manual calculation is prone to errors and cannot guarantee the test accuracy of the motor. Digital multimeters are used to test the static parameters such as motor winding resistance and contact resistance. In this process, the tester needs to manually switch the wiring or replace the instrument channel multiple times to complete the test of different items. The existing test process is tedious and inefficient. SUMMARY

[0004] In order to solve the defects of poor test accuracy, tedious test process and low efficiency of the prior art, the present application provides a limited rotation angle motor testing system.

[0005] The technical scheme of the present application is: a limited rotation angle motor testing system, comprising a measurement and control computer, a test voltage circuit, a test resistance circuit and a power supply.

[0006] The test voltage circuit comprises an MCU processing unit, an AD conversion unit and a voltage acquisition unit. The voltage acquisition unit is used to acquire the voltage signal of the limited rotation angle motor, and then transmit the voltage signal to the AD conversion unit. The AD conversion unit is used to convert the acquired voltage signal into a digital signal and transmit it to the MCU processing unit. The MCU processing unit automatically identifies the starting point and the ending point of the action according to the change curve of the voltage signal, calculates the unlocking time and the reset time of the motor, and transmits the unlocking time and the reset time to the measurement and control computer.

[0007] The test resistance circuit comprises a digital multimeter, which is used to test the motor resistance signal and transmit it to the measurement and control computer.

[0008] The measurement and control computer is used to send test instructions to the MCU processing unit and the digital multimeter, and receive test data transmitted by the MCU processing unit and the digital multimeter.

[0009] The power supply is respectively for the measurement and control computer, the MCU processing unit, the AD conversion unit, the voltage acquisition unit and the digital multimeter.

[0010] Preferably, the voltage acquisition unit acquires the voltage signal of the limited rotation angle motor through the acquisition voltage relay unit, and the MCU processing unit controls the on-off of the test voltage circuit through the acquisition voltage relay unit.

[0011] Preferably, the digital multimeter tests the resistance signal of the limited rotation angle motor through the acquisition resistance relay unit, and the MCU processing unit controls the on-off of the test resistance circuit through the acquisition resistance relay unit.

[0012] Preferably, the MCU processing unit, the AD conversion unit, the voltage acquisition unit, the acquisition voltage relay unit and the acquisition resistance relay unit are integrated on the motor control board.

[0013] Preferably, the digital multimeter has a current positive terminal, a current negative terminal, a voltage positive terminal and a voltage negative terminal.

[0014] The present application has the following advantages: the measurement and control computer respectively sends test instructions to the test voltage circuit and the test resistance circuit, controls the test voltage circuit to test the unlocking time and the reset time of the limited rotation angle motor, controls the test resistance circuit to test the resistance of the limited rotation angle motor, and then transmits the data to the measurement and control computer, so that the unlocking time, the reset time and the resistance parameter of the limited rotation angle motor are automatically tested without manual calculation, and the test precision and efficiency are improved. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a limited rotation angle motor test system block diagram;

[0016] Figure 2 It is a limited rotation angle motor action process voltage waveform diagram;

[0017] Figure 3 It is a limited rotation angle motor test system overall block diagram;

[0018] Figure 4 It is a digital multimeter wiring diagram. DETAILED DESCRIPTION

[0019] In order to better understand the inventive concept, the technical scheme of the present application will be further described in detail below in combination with the drawings and specific embodiments.

[0020] The technical scheme of the present application is as follows: a limited rotation angle motor test system, as shown in Figure 1 It comprises a measurement and control computer, a test voltage circuit, a test resistance circuit and a power supply.

[0021] The test voltage circuit is used to acquire the voltage signal of the motor during power-on and power-off processes. The test voltage circuit includes an MCU processing unit, an AD conversion unit, and a voltage acquisition unit. To avoid the influence of external electromagnetic interference and surge voltage during the test on the sampling accuracy, the input terminal of the voltage acquisition unit is equipped with an isolation amplifier circuit and a low-pass filter circuit. The voltage acquisition unit acquires the voltage signal of the limited-angle motor during power-on and power-off processes through the isolation amplifier circuit, and then transmits the voltage signal to the AD conversion unit. The AD conversion unit converts the acquired voltage signal from analog to digital and transmits it to the MCU processing unit. The MCU processing unit uses an STM32F407VET6 ARM processor. The MCU processing unit automatically identifies the start and end points of the action based on the voltage signal change curve and calculates the motor's unlocking and reset times. The specific working principle is as follows: Figure 2 As shown, during the motor unlocking process, the voltage is the initial reference value when the power is off. After the power is on, the voltage rises rapidly and fluctuates with the load, eventually stabilizing at the working voltage. During the reset process, the voltage drops rapidly after the power is off and fluctuates with the mechanical return, eventually returning to the initial reference value. The unlocking start point is when the voltage first exceeds the initial reference value, and the reset start point is when the voltage first falls below the working voltage. The end point is then identified by combining the stable threshold range with the stable duration. The unlocking end point is the timestamp when the voltage enters the stable range and remains stable, and the reset end point is the timestamp when the voltage returns to the reference stable range and remains stable. Finally, the unlocking time and reset time are calculated and transmitted to the measurement and control computer.

[0022] The resistance test circuit is used to test the resistance of the motor. The resistance test circuit includes a digital multimeter, which tests the motor resistance signal and transmits it to the measurement and control computer.

[0023] The measurement and control computer is used to send test commands to the MCU processing unit and the digital multimeter, and to receive test data transmitted by the MCU processing unit and the digital multimeter. The measurement and control computer runs the supporting test software, which includes a test task configuration module, an instruction control module, a data acquisition module and a result analysis module. The test results are displayed in real time in graphical and numerical form, and the software can automatically determine whether the test results are qualified.

[0024] The power supplies are for the measurement and control computer, MCU processing unit, AD conversion unit and voltage acquisition unit, and digital multimeter.

[0025] like Figure 3 As shown, the voltage acquisition unit acquires the voltage signal of the limited-angle motor through the voltage acquisition relay unit. The MCU processing unit controls the on / off state of the test voltage circuit through the voltage acquisition relay unit according to the test instructions of the measurement and control computer. Figure 2As shown, the digital multimeter collects the resistance signal of the resistance relay unit to test the limited angle motor, and the MCU processing unit controls the on-off of the test resistance circuit according to the test instruction of the test and control computer.

[0026] As shown in the figure, Figure 3 The MCU processing unit, the AD conversion unit, the voltage collection unit, the collection voltage relay unit and the collection resistance relay unit are integrated on the motor control board, the MCU processing unit communicates with the test and control computer through the RS232 communication interface, and the collection resistance relay unit is connected with the digital multimeter through the USB interface.

[0027] As shown in the figure, Figure 4 As shown in the figure, the digital multimeter measures the resistance of the limited angle motor by four-wire test method. In the specific test process, the current positive terminal (I+) and the current negative terminal (I-) of the digital multimeter are connected to the two ends of the limited angle motor respectively, for applying a constant test current to the limited angle motor; the voltage positive terminal (V+) and the voltage negative terminal (V-) are connected in parallel to the measurement points at the two ends of the limited angle motor, for detecting the voltage drop at the two ends of the limited angle motor. During the test, the constant current source I of the digital multimeter outputs a constant current through the current loop, which flows through the limited angle motor, thereby generating a voltage drop at the two ends of the limited angle motor; at the same time, the voltage measurement loop works independently, and since its input impedance is very high, almost no current flows through it, so there will be no additional voltage drop at the lead or contact. The voltage signal collected by the digital multimeter is only the true voltage drop at the two ends of the measured resistance, and the resistance value is automatically calculated through Ohm's law R=V / I. This four-wire test method effectively eliminates the influence of lead resistance, contact resistance and connection point voltage drop on the measurement results, can significantly improve the accuracy and repeatability of low resistance measurement, and ensures the stability and reliability of the test data.

[0028] To adapt to the batch test demand of multiple limited angle motors, the voltage collection unit can be expanded to a multi-channel collection structure, each collection channel corresponds to a limited angle motor test interface, and the multi-channel time-sharing collection or parallel collection mode is realized through the MCU control multi-channel sampling relay unit, which can complete the unlocking time, reset time and resistance parameter test of multiple motors at the same time, thereby significantly improving the test efficiency.

[0029] The above only describes the preferred embodiments of the present application, and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A limited rotation motor test system, characterized by: The test voltage circuit, the test resistance circuit, and the power supply are included. The test voltage circuit includes an MCU processing unit, an AD conversion unit, and a voltage acquisition unit. The voltage acquisition unit is configured to acquire a voltage signal of the limited rotation motor, and transmit the voltage signal to the AD conversion unit. The AD conversion unit is configured to convert the acquired voltage signal into a digital signal, and transmit the digital signal to the MCU processing unit. The MCU processing unit is configured to automatically identify a starting point and an ending point of an action according to a change curve of the voltage signal, calculate an unlock time and a reset time of the motor, and transmit the unlock time and the reset time to the test control computer.

2. The limited rotation motor testing system of claim 1, wherein: The test resistance circuit includes a digital multimeter.

3. A limited angle motor testing system according to claim 2, wherein: The digital multimeter is configured to test a resistance signal of the motor, and transmit the resistance signal to the test control computer.

4. A limited angle motor testing system according to claim 3, wherein: The test control computer is configured to send a test instruction to the MCU processing unit and the digital multimeter, and receive test data transmitted by the MCU processing unit and the digital multimeter.

5. The limited rotation motor testing system of claim 1 or 3, wherein: The power supply is configured to supply power to the test control computer, the MCU processing unit, the AD conversion unit, the voltage acquisition unit, and the digital multimeter. The voltage acquisition unit acquires the voltage signal of the limited rotation motor through a voltage relay unit. The MCU processing unit controls the test voltage circuit through the voltage relay unit according to the test instruction of the test control computer. The digital multimeter tests the resistance signal of the limited rotation motor through a resistance relay unit. The MCU processing unit controls the test resistance circuit through the resistance relay unit according to the test instruction of the test control computer. The MCU processing unit, the AD conversion unit, the voltage acquisition unit, the voltage relay unit, and the resistance relay unit are integrated on a motor control board. The digital multimeter has a current positive terminal, a current negative terminal, a voltage positive terminal, and a voltage negative terminal.

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