FCT test system

Abstract

The utility model belongs to the technical field of automatic testing, and particularly relates to an FCT testing system. The system comprises an upper computer and a test fixture, the test fixture is provided with a needle bed, the needle bed is provided with a plurality of groups of probes used for being connected with pins of input and output interfaces of a control circuit board and external interfaces arranged in one-to-one correspondence with the groups of probes, and the external interfaces are connected with the corresponding probes; and the upper computer is connected with the external interface through a data line. The probes on the probe bed are connected with the pins of the input and output interfaces of the tested control circuit board, during testing, the control circuit board can send current signals to the input and output interfaces at the same time, the current signals are obtained by the upper computer through the probes and the data lines, the upper computer can detect the input and output interfaces at the same time, and the testing efficiency is improved. And the detection efficiency is effectively improved.

Description

Technical Field

[0001] This application belongs to the technical field of automated testing, and particularly relates to an FCT testing system. Background Art

[0002] An FCT (Functional Circuit Test) functional test device provides a simulated excitation operating environment for the control circuit board to be tested according to the conditions required for its operation, enabling the circuit board to be tested to operate in various designed working states, such as normal working state and fault protection working state. By obtaining various parameters in each operating state, it is used to determine the quality of its function.

[0003] Currently, there are many items in FCT functional testing. Most of them are tested one by one manually. If a large number of control circuit boards are operated step by step solely by testers, it will be very time-consuming, with low efficiency and affecting the production progress. Summary of the Utility Model

[0004] The purpose of this application is to provide an FCT testing system, aiming to solve the problem of low efficiency in traditional control circuit boards during FCT functional testing.

[0005] The first aspect of the embodiment of this application provides an FCT testing system.

[0006] An FCT testing system includes: a host computer and a test fixture. The test fixture is provided with a bed of pins. The bed of pins is provided with several groups of probes for connecting to the pins of each input / output interface of the control circuit board, and external interfaces corresponding to each group of probes are provided. The external interfaces are connected to the corresponding probes; the host computer is connected to the external interfaces through a data cable.

[0007] In one embodiment, the host computer is connected to a program burner.

[0008] In one embodiment, the host computer is provided with a memory and is connected to a barcode scanner.

[0009] In one embodiment, the host computer is connected to a display.

[0010] In one embodiment, the test fixture is provided with a power supply circuit, a power conversion circuit, and a voltage relay. The power supply circuit is used to connect to the commercial power and convert the commercial power into direct current. The power conversion circuit is connected to the power supply circuit and is used to output 5V or 12V direct current. The power conversion unit supplies power to the control circuit board to be tested through the voltage relay; the host computer is electrically connected to the control end of the voltage relay, and the host computer controls the power supply of the power conversion unit to the control circuit board to be tested.

[0011] In one embodiment, the power supply circuit includes an EMI circuit, a rectifier circuit, and a constant voltage control circuit connected in sequence; wherein, the constant voltage control circuit includes a constant voltage control chip, a transformer, and a switching tube. The transformer includes a primary coil, a secondary coil, and a secondary-secondary coil. The secondary coil is connected to the ground through the switching tube. The secondary-secondary coil supplies power to the constant voltage control chip and is connected to the detection end of the constant voltage control chip through a voltage division circuit. The constant voltage control chip is electrically connected to the control end of the switching tube.

[0012] In one embodiment, a multiplexer is further included. The multiplexer is connected to multiple external interfaces; the host computer is connected to the multiplexer.

[0013] In one embodiment, the test fixture is provided with a positioning connection structure for connecting with the control circuit board.

[0014] In one embodiment, the positioning connection structure includes an L-shaped clamping block provided on the test fixture.

[0015] In one embodiment, the positioning connection structure includes positioning posts provided on the test fixture.

[0016] The beneficial effects of the embodiment of the present application compared with the prior art are as follows: By connecting the probes on the needle bed to the pins of the input / output interfaces of the control circuit board to be measured, during the test, the control circuit board can simultaneously send current signals to multiple input / output interfaces. The current signals are obtained by the host computer through the probes and the data lines, and the host computer can simultaneously detect multiple input / output interfaces, effectively improving the detection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the principle of an FCT test system provided by an embodiment of the present application; for the convenience of expression, the control circuit board to be measured is also shown;

[0018] Figure 2 It is a schematic diagram of the cooperation between the control circuit board to be measured and the test fixture when the FCT test system of this embodiment is applied;

[0019] Figure 3 It is a schematic diagram of a power supply circuit of this embodiment;

[0020] Figure 4 It is a schematic diagram of a power conversion circuit of this embodiment;

[0021] Figure 5 It is another schematic diagram of a power conversion circuit of this embodiment;

[0022] Figure 6 It is a schematic diagram of a test process when the FCT test system performs an FCT test;

[0023] Figure 7 It is a schematic diagram of the test process for the FCT test system to perform the drive test of the power switch tube;

[0024] The reference numerals in the drawings are as follows:

[0025] 1 - Host computer; 2 - Test fixture; 3 - Control circuit board; 4 - External interface; 5 - Probe; 6 - Multiplexer; 7 - Program burner; 8 - Display; 9 - Barcode scanner; 10 - Memory; 31 - Input / output interface. Detailed implementation manners

[0026] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application clearer and more understandable, the present application will be further described in detail below in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0027] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0028] It should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present application.

[0029] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality of" means two or more unless otherwise specifically defined.

[0030] Figure 1 The figure shows a schematic diagram when the FCT test system provided by the preferred embodiment of the present application is working. For the convenience of description, only the parts related to this embodiment are shown and are described in detail as follows:

[0031] An FCT test system, which includes: a host computer 1 and a test fixture 2. The test fixture 2 is provided with a bed of needles. The bed of needles is provided with several groups of probes 5 for connecting to the pins of each input / output interface 31 of the control circuit board 3, and external interfaces 4 arranged in one-to-one correspondence with each group of probes 5. The external interfaces 4 are connected to the corresponding probes 5; the host computer 1 is connected to the external interfaces 4 through a data cable.

[0032] When the technical solution of this application is specifically implemented, as Figure 1 shown, the to-be-tested control circuit board 3 is first fixedly connected to the test fixture 2 through a positioning connection structure. The pins of each input / output interface 31 of the tested control circuit board 3 are correspondingly connected to each group of probes 5 on the test fixture 2. When specifically setting, the test fixture 2 is made according to the tested control circuit board 3, and each group of probes 5 on it corresponds one-to-one to each input / output interface 31 on the tested control circuit board 3; currently, the input / output interfaces 31 mainly include various EPWM interfaces, ADC interfaces, GPIO interfaces, etc.; when the host computer 1 communicates with the test fixture 2, the host computer 1 is connected to the external interface 4 on the test fixture 2 in a serial communication manner.

[0033] During the test, the to-be-tested control circuit board 3 emits corresponding control current signals outward from the test input / output interface 31. Since each group of probes 5 on the bed of needles is correspondingly connected to the input / output interface 31, these control current signals flow to the corresponding external interfaces 4 through the corresponding group of probes 5, and then are received by the host computer 1 through the serial port. The host computer 1 detects the control current signals to judge whether it works properly.

[0034] In some embodiments, to facilitate fixing the to-be-tested control circuit board 3 on the test fixture 2, the test fixture 2 is provided with a positioning connection structure for connecting to the control circuit board 3. The positioning connection structure is used to position the position where the tested control circuit board 3 is placed, to avoid misplacement or displacement during the test; the positioning structure can adopt 2 or 3 or 4 L-shaped blocks. When adopting 2 L-shaped blocks, the 2 L-shaped blocks are, for example, arranged diagonally, and the L-shaped blocks abut against the two diagonal ends of the tested control circuit board 3 and limit the movement of the tested control circuit board 3. Exemplarily, the abutting surface of the L-shaped block against the tested control circuit board 3 is inclined. When putting the tested control circuit board 3 in, the side surface of the tested control circuit board 3 abuts against part of the abutting surfaces of the L-shaped blocks, and there is a gap between the side surface of the tested control circuit board 3 and part of the abutting surfaces of the L-shaped blocks. The tested control circuit board 3 moves downward along the abutting surface, and the abutting surface with the L-shaped blocks gradually increases until it abuts against all the abutting surfaces; it is convenient to put the tested control circuit board 3 in. Secondly, to facilitate guiding the positioning of the control circuit 3 and the test fixture 2, positioning posts can be provided on the test fixture 2, and positioning holes matching the positioning posts are provided on the control circuit board 3. Through the guidance of the positioning posts, it is convenient to quickly position the control circuit board 3.

[0035] See Figure 1 , for the convenience of programming, the host computer 1 is connected to a program burner 7.

[0036] The host computer 1 generally uses a desktop computer, an engineering machine, etc. The host computer 1 is provided with an engineering creation module for creating various test programs. After the host computer 1 creates a test program corresponding to the control circuit board 3 to be tested through the engineering creation module, it burns the test program to the control circuit board 3 to be tested through the program burner 7. During implementation, the control circuit board 3 to be tested is provided with a burning interface, and the burning interface is connected to the program burner 7 through a data line. Secondly, the burning interface is connected to a set of probes 5 on the test fixture 2 as an input / output interface 31, and at the same time, the external interface 4 corresponding to the set of probes 5 is connected to the host computer 1 through a data line, and the host computer 1 detects the burning progress through the current signal of the burning interface.

[0037] When the control circuit board 3 to be tested is produced, it is a blank control circuit board 3, that is, the control chip does not have any execution program. During testing, the host computer 1 burns a test program to the control chip through the program burner 7. After the test is successful, the host computer 1 erases the FCT program through the burning module, then reads the whole machine program under a fixed path and burns it to write the working execution program.

[0038] For the convenience of data storage, the host computer 1 is provided with a memory 10 and is connected to a barcode scanner 9.

[0039] When testing the control circuit board 3 to be tested, the test results need to be corresponding to the control circuit board 3 to be tested one by one. To make the test data corresponding to the control circuit board 3 to be tested, currently, a barcode is pasted or printed on the control circuit board 3 to be tested. The barcode corresponds to the serial number of the control circuit board 3 to be tested. The barcode scanner 9 scans the barcode to obtain the serial number of the control circuit board 3 to be tested. At the same time, the memory 10 stores it and stores the corresponding test data.

[0040] In practical applications, the host computer 1 uses a PC. The test project is created through the PC, that is, a test program is established. The test programs for different control circuit boards 3 to be tested may be different. For example, the control circuit board 3 of type A conducts type-a tests, and the control circuit board 3 of type B conducts type-b tests. When the control circuit board 3 to be tested conducts an FCT test, it is first scanned by the barcode scanner 9 to obtain the information of the control circuit board 3 to be tested, determine the model of the control circuit board 3, and then select an appropriate test program. The test program is burned into the control circuit board 3 to be tested through the program burner 7. The control circuit board 3 to be tested acts according to the test program and sends a control current signal to the input / output interface 31. The control current signal is transmitted back to the host computer 1 through the probe 5 and the external interface 4. The host computer 1 detects the control current signal to determine whether the control circuit board 3 to be tested is qualified. Secondly, the host computer 1 communicates with the control circuit board 3 to be tested through a serial port to realize the issuance of instructions and the upload of data, that is, the external interface 4 is electrically connected to the host computer 1 through the serial port.

[0041] Meanwhile, for the convenience of displaying various detection data, a display 8 is connected to the host computer 1.

[0042] The display 8 is used to display various detection information. For example, in the initial stage, when the host computer 1 burns a program into the control circuit board 3 through the program burner 7, the progress of the burned program can be displayed through the display 8. Another example is that when a certain function of the control circuit board 3 to be tested is detected, the detection result is displayed on the display 8. When the control circuit board 3 to be tested is scanned, the scanning result is displayed on the display 8, such as the barcode information of the control circuit board 3 to be tested is displayed on the display 8, and so on.

[0043] See Figures 3 to 5 As shown, the test fixture 2 is provided with a power supply circuit, a power conversion circuit, and a voltage relay. The power supply circuit is used to connect to the commercial power and convert the commercial power into direct current. The power conversion circuit is connected to the power supply circuit and is used to output direct current of 5V or 12V. The power conversion unit supplies power to the control circuit board 3 to be tested through the voltage relay. The host computer 1 is electrically connected to the control end of the voltage relay, and the host computer 1 controls the power supply of the power conversion unit to the control circuit board 3 to be tested.

[0044] In an embodiment of the present application, the control circuit board 3 to be measured can be the main control board of an energy storage inverter, which needs to sample a variety of signals, such as current sampling, voltage sampling, temperature sampling, etc. To detect the accuracy of the sampling, according to the specific test items, the host computer 1 controls the connected voltage relay, and the output end of the voltage relay is electrically connected to the sampling interface of the control circuit board 3 to be measured. The host computer 1 makes the control circuit board 3 to be measured obtain different voltage input sampling tests by controlling the output of the voltage relay; the power conversion circuit is a DC-DC circuit, which is used to reduce the output voltage of the power supply circuit. At present, the control circuit board 3 to be measured generally uses three voltages of 5V, 12V, and 15V. Therefore, there are 3 voltage conversion circuits, which are respectively used to output 5V direct current, 12V direct current, and 15V direct current; at the same time, the host computer 1 is electrically connected to the chip of the control circuit board 3 to be measured through a data line, obtains the result of the sampling test of the control circuit board 3 to be measured, and compares the output voltage of the voltage relay with the voltage obtained by the sampling test, so as to judge whether the sampling test of the control circuit board 3 to be measured is accurate.

[0045] Secondly, when performing signal sampling, generally voltage information is collected, and the corresponding current information and temperature information are converted according to the voltage information. When sampling, the temperature generally changes continuously. Therefore, the collected voltage information also changes continuously correspondingly. To obtain continuous voltage information, a voltage dividing circuit can be used. The voltage dividing circuit includes a fixed resistor and a variable resistor. The variable end of the variable resistor is connected to the linear module. The linear module drives the continuous movement of the variable end, and the resistance value of the variable resistor changes continuously, so that the potential of the voltage dividing circuit collected is continuously changed, thereby judging whether the sampling test is qualified.

[0046] See Figure 3 , the power supply circuit includes an EMI circuit, a rectification circuit, and a constant voltage control circuit connected in sequence; wherein, the constant voltage control circuit includes a constant voltage control chip, a transformer, and a switching tube. The transformer includes a primary coil, a secondary coil, and a secondary-secondary coil. The secondary coil is connected to the ground through the switching tube. The secondary-secondary coil provides power for the constant voltage control chip and is connected to the detection end of the constant voltage control chip through a voltage dividing circuit. The constant voltage control chip is electrically connected to the control end of the switching tube.

[0047] The power supply circuit is connected to the mains power supply and is used to receive 220V alternating current; the EMI (Electromagnetic Interference) circuit is used to eliminate or weaken electromagnetic interference and resist electromagnetic interference; the rectifier circuit is used to convert the mains alternating current into direct current. The EMI circuit and the rectifier circuit can both adopt existing technologies. In this embodiment, the EMI circuit adopts a combination of a common-mode circuit and a differential-mode circuit. The common-mode circuit adopts a common-mode inductor L3, and the differential-mode circuit adopts a capacitor CX1; the rectifier circuit adopts a full-bridge circuit. The secondary side coil generates an induced voltage and provides power to the constant voltage control chip; and at the same time, a feedback voltage signal is provided to the detection end of the constant voltage control chip through a voltage division circuit; the constant voltage control chip controls the on-off frequency of the switching tube according to the feedback voltage signal, and then controls the constant voltage output of the secondary side coil. The model of the constant voltage control chip can be the NJM2336 series, etc.

[0048] See Figure 1 , and further includes a multiplexer 6, which is connected to a plurality of external interfaces 4; the host computer 1 is connected to the multiplexer 6. The measured control circuit board 3 generally has a plurality of sampling interfaces. For example, there are 16 AD sampling interfaces on the TMS320F28069 chip. During testing, it is necessary to input current to the 16 AD sampling interfaces. If 16 power supplies are used to connect to them one by one, the cost will be very high; to reduce the cost, channel multiplexing needs to be designed; in the embodiment of the present application, the SN74CBTLV3257 multiplexer 6 is exemplarily adopted, and the selection input of the multiplexer 6 is controlled by software to control the switching of sampling of the data stream. As in this embodiment, the data that needs to be sampled by the measured control circuit board 3 are: inverter voltage and current, battery low-voltage side voltage, inverter temperature, PV voltage and current of 2 paths, DC bus voltage, grid voltage and current, load voltage and current, battery temperature, leakage current, DC LINK voltage, PV insulation voltage, battery high-voltage side current, inverter DC voltage and current, ground voltage. During testing, the host computer 1 controls the power supply to be connected to the external interface 4 corresponding to the sampling interface through the multiplexer 6. The host computer 1 controls the power supply to output a current signal. The multiplexer 6 selects the sampling switching of the data stream. The data stream enters the sampling interface (input interface) through different external interfaces 4. The chip of the measured control circuit board 3 detects the sampling signal and sends the sampling signal to the host computer 1 through the data line.

[0049] When conducting tests, the host computer 1 sends a command to start the FCT test to the control circuit board 3 via serial communication. After the chip on the control circuit board 3 receives the signal to start the FCT test sent by the host computer 1, it begins to send a current signal to the output interface in the input / output interface 31, and the input interface receives the external current signal. For example, in sampling tests, temperature sampling, voltage sampling, and current sampling can be performed. During the test, the host computer 1 controls the voltage source to input a current signal to the sampling interface, and the current signal is transmitted to the host computer 1 through the probe 5, the external interface 4, and the data line. At the same time, this current signal is also transmitted to the chip of the control circuit board 3 under test. Since the chip and the host computer 1 establish communication through the data line, the chip transmits the acquired current signal to the host computer 1, and the host computer 1 compares the two current signals to determine whether the sampling interface of the control circuit board 3 of the circuit under test is working properly.

[0050] The control circuit board 3 is mainly a DSP control circuit board 3, which is controlled by TMS320F28069 as the core. The FCT DSP control mainly controls the sampling of the operation data of the energy storage inverter (ADC sampling); drives the power switch tubes to conduct and turn off, and outputs PWM with a specified frequency and duty cycle (EPWM peripheral module, configured to generate PWM signals); turns off and closes the relay (GPIO, that is, the IO port); communication function (CAN communication, SCI serial communication). During the test, the control circuit board 3 is placed on the pin bed of the test fixture 2, and the probe 5 on the pin bed is connected to the input / output pins of the control circuit board 3 and leads out the external interface 4 to be connected to the host computer 1. The programming module is connected to the programming port (JTAG port) of the control circuit board 3 by a programming tool for programming the program.

[0051] See Figure 6 , during the sampling test, temperature sampling, voltage sampling, and current sampling are mainly carried out; during the power switch drive test, it is mainly for: the full-bridge inverter switch tube, the PV BOOST boost switch tube, and the DC-DC switch tube; for the relay test, it is mainly for the grid-connected relay, the off-grid relay, and the bypass relay; for the communication test, it is mainly for Can communication and serial communication. See the FCT test flow chart.

[0052] See Figure 7 , now taking the power switch tube drive test as an example for illustration; the host computer 1 sends a control command for the power switch tube drive test to the chip of the control circuit board 3, and the chip sends out a control current signal through the EPWM module, such as the full-bridge inverter switch tube drive signal, the PV BOOST boost switch tube drive signal, and the DC-DC switch tube signal. These signals are directly transmitted to the host computer 1 through the external interface or through the multiplexer 6; the host computer 1 detects the frequency and duty cycle of these signals.

[0053] When outputting a current signal externally through the output interface, the host computer 1 sends a test signal to the chip of the control circuit board 3 under test through the data line, and the chip of the control circuit board 3 under test will send a PWM current signal to the output interface; multiple EPWM modules are provided on the control circuit board 3. For convenience of description, they are set as EPWM1, EPWM2, etc.

[0054] The input interface includes: ADC interface, programming interface, etc.; the output interface includes: EPWM interface, GPIO interface, etc.; the input / output interface 31 includes: SCI serial port, CAN interface, etc.

[0055] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A FCT test system, characterized in that: include: A host computer and a test fixture, wherein the test fixture is provided with a needle bed, the needle bed is provided with a plurality of groups of probes for connecting to the pins of the various input and output interfaces of the control circuit board, and an external interface is arranged in a one-to-one correspondence with each group of the probes, and the external interface is connected to the corresponding probe; the host computer is connected to the external interface via a data line.

2. The FCT test system according to claim 1, characterized in that: The host computer is connected with a program burner.

3. The FCT test system according to claim 1, characterized in that: The host computer is provided with a memory and is connected with a code scanner.

4. The FCT test system according to any one of claims 1 to 3, characterized in that: The host computer is connected with a display.

5. The FCT test system according to claim 1, characterized in that: The test fixture is provided with a power supply circuit, a power conversion circuit and a voltage relay. The power supply circuit is used to connect to the mains and convert the mains into direct current. The power conversion circuit is connected to the power supply circuit and is used to output 5V or 12V direct current. The power conversion unit supplies power to the control circuit board under test through the voltage relay. The host computer is electrically connected to the control end of the voltage relay, and the host computer controls the power supply of the power conversion unit to the control circuit board under test.

6. The FCT test system according to claim 5, characterized in that: The power supply circuit includes an EMI circuit, a rectifier circuit and a constant voltage control circuit connected in sequence; wherein the constant voltage control circuit includes a constant voltage control chip, a transformer and a switch tube, the transformer includes a primary coil, a secondary coil and a sub-secondary coil, the secondary coil is connected to the ground through the switch tube, the sub-secondary coil provides power to the constant voltage control chip, and is connected to the detection end of the constant voltage control chip through a voltage divider circuit, and the constant voltage control chip is electrically connected to the control end of the switch tube.

7. The FCT test system according to claim 1, characterized in that: The invention also comprises a multiplexer, wherein the multiplexer is connected with a plurality of external interfaces; and a host computer is connected with the multiplexer.

8. The FCT test system according to claim 1, characterized in that: The test fixture is provided with a positioning connection structure for connecting with the control circuit board.

9. The FCT test system according to claim 8, characterized in that: The positioning connection structure includes an L-shaped block arranged on the test fixture.

10. The FCT test system according to claim 8, characterized in that: The positioning connection structure includes a positioning column arranged on the test fixture.

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