Resistance simulation device for integrated test of automobile electric appliance function system

Abstract

The application discloses a kind of resistance simulation equipment for automobile electric appliance function system integrated test, including external interface, CAN bus transceiver module, single-chip microcomputer, relay drive module, resistance control adjustment module and resistance back extraction module.Resistance control adjustment module includes at least one discrete resistance array and relay array, for adjusting theoretical output resistance value.Resistance back extraction module is used to collect the actual resistance value of the output end of the resistance simulation equipment for automobile electric appliance function system integrated test.Single-chip microcomputer receives digital signal and analyzes CAN communication message, and sends control instruction according to the difference between theoretical output resistance value and actual resistance value, to control relay drive module, to form closed-loop control.The application can be conveniently installed in the cabinet of automobile electric appliance function system integrated test bench, and has multiple channels, wide adjustable range, high resolution, high precision, convenient control and easy expansion, which meets the needs of precise simulation of various resistance signals for automobile electric appliance function system integrated test.

Description

Technical Field

[0001] This invention relates to the field of automotive electrical function testing, and more specifically to a resistance simulation device for automotive electrical function system integration testing. Background Technology

[0002] Before a car is launched on the market, it needs to undergo extensive testing, including testing of the vehicle's electrical functions. It is usually difficult to achieve the required environmental conditions in real-world testing environments. For example, it is impossible to achieve a wide range of temperature changes in a laboratory environment, and some extreme temperature values ​​that indicate malfunctions are also difficult to achieve in a real vehicle.

[0003] Therefore, to improve testing efficiency and reduce testing costs, it is necessary to build a vehicle electrical function system integration test bench for signal-level functional testing. This bench simulates various sensors and body switches to control environmental variables and meet testing conditions. Among these, the simulation of resistance signals is a crucial and challenging aspect of signal simulation. Temperature signals such as ambient temperature, engine intake air, and coolant, as well as many body switch signals such as window regulator switches, central locking / unlocking, exterior mirror adjustment, seat adjustment, and electronic parking brake, are all resistance signals with wide applications. This also means that automotive electrical function system integration testing requires extensive simulation of various types of resistance signals, and the accuracy of the resistance signal simulation directly determines the test quality.

[0004] However, existing simulator racks have limited resistor channels, and adding resistor boards is expensive and has long lead times. Therefore, there is a need for a high-resolution, high-precision resistor simulation device that can be installed in a test bench rack, is easily expandable in number, and is conveniently controllable for ECU hardware-in-the-loop testing. Summary of the Invention

[0005] The purpose of this invention is to provide a multi-channel, high-resolution, and high-precision resistance signal simulation device that can be installed in the cabinet of an automotive electrical function system integration test bench, is easily expandable in number, and is convenient to control.

[0006] To achieve the above objectives, the present invention provides a resistance simulation device for automotive electrical function system integration testing, which is installed in the cabinet of an automotive electrical function system integration test bench. The resistance simulation device includes an external interface, a CAN bus transceiver module, a microcontroller, a relay drive module, a resistance control and adjustment module, and a resistance feedback module.

[0007] The external interface is connected to the cabinet and is used for mechanical fixation, receiving electrical signals from the cabinet and outputting resistance signals to the cabinet. The electrical signals include CAN physical signals.

[0008] The CAN bus transceiver module converts the received CAN physical signals into digital signals and sends the digital signals to the microcontroller.

[0009] The microcontroller receives digital signals and parses CAN messages, identifies the status of the resistance control adjustment module and the resistance feedback module, and controls the relay drive module.

[0010] The resistance control adjustment module includes at least one discrete resistor array and a relay array, used to adjust the theoretical output resistance value;

[0011] The relay driver module is located between the microcontroller and the relay array and is used to drive the relays;

[0012] The resistance recovery module is used to collect the actual resistance value at the output of the resistance simulation device.

[0013] The microcontroller issues control commands based on the difference between the theoretical output resistance value and the actual resistance value to control the relay drive module.

[0014] In one embodiment, the cabinet is equipped with a pull-out aid and a back panel, and the external interface includes a mechanical fixing interface and an electrical signal interface;

[0015] The mechanical fixing interface is a front end baffle, which is located at the front end of the resistance simulation device. The front end baffle is connected to the cabinet through the fixing hole on the puller.

[0016] The electrical signal interface is a back-end electrical connector, which is connected to the backplane to connect the output resistance signal of the resistance simulation device to the cabinet, and at the same time connects the power supply and CAN control signals from the cabinet to the resistance simulation device.

[0017] In one embodiment, the front end baffle is a 3U standard size, and the rear end electrical connector is a Harding 96-pin bent male plug.

[0018] In one embodiment, in the resistor control adjustment module, the discrete resistor array is composed of several discrete resistors connected in series, and a relay is connected in parallel to each discrete resistor. By combining the opening and / or closing of multiple relays, the series connection of discrete resistors with different resistance values ​​is controlled to adjust the theoretical output resistance value.

[0019] In one embodiment, the relay is a double-pole double-throw type, which disconnects or closes two independent circuits. One circuit serves as an output resistor circuit, and the other serves as a shadow circuit. The shadow circuit has the same state as the output resistor circuit. When adjusting the theoretical output resistance, the output resistor circuit is connected to the resistance feedback module, and the shadow circuit is connected to an external circuit.

[0020] In one embodiment, the resistance feedback module includes a constant current source circuit and a voltage acquisition circuit. The constant current generated by the constant current source circuit converts the resistance signal of the output resistance circuit into a voltage signal, which is then converted into a digital quantity by the voltage acquisition circuit and transmitted to the microcontroller for closed-loop control.

[0021] In one embodiment, a discrete resistor array consists of 6 groups of 24 discrete resistors connected in series to form an output resistor circuit. Each group of discrete resistors is assigned using a 1-2-3-4 arrangement to represent the ones, tens, hundreds, thousands, ten thousands, and hundred thousands place of the output resistor, respectively.

[0022] In one embodiment, the resistance simulation device has at least one resistance channel, and each resistance channel has an output resistance circuit and a resistance sampling module.

[0023] In one embodiment, each resistor channel can output any resistance value in the range of 0 to 1111.11k ohms with a resolution of 1 ohm.

[0024] In one embodiment, the relay drive module includes a Darlington transistor.

[0025] The beneficial effects of the resistance simulation device for automotive electrical function system integration testing of the present invention are as follows:

[0026] 1. This invention can be easily installed in the cabinet of an automotive electrical function system integration test bench.

[0027] 2. The single device of the present invention has 4 channels, each of which can be continuously adjusted between 0 ohms and 1111.11k ohms with an adjustment step of 1 ohm, resulting in high resolution and a wide adjustment range.

[0028] 3. Due to the inclusion of a resistance feedback module, this invention can achieve online resistance measurement, forming a closed-loop control and significantly improving the accuracy of the output resistance.

[0029] 4. This invention uses CAN bus communication, which allows for easy integration into any system with a CAN interface. This invention is easily expandable, convenient to control, and meets the high demand for resistance simulation channels in automotive electrical function system integration testing. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of a resistance simulation device for automotive electrical function system integration testing according to an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of a resistance control adjustment module according to an embodiment of the present invention;

[0032] Figure 3This is a schematic diagram of a resistance sampling module according to an embodiment of the present invention; and

[0033] Figure 4 This is a software control flowchart of a resistor simulation device for automotive electrical function system integration testing according to an embodiment of the present invention. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0035] like Figure 1 As shown, a resistor simulation device for automotive electrical function system integration testing (hereinafter referred to as "resistance simulation device") according to an embodiment of the present invention is installed in the cabinet (hereinafter referred to as "cabinet") of the automotive electrical function system integration test bench, including an external interface 1, a CAN bus transceiver module 2, a microcontroller 3, a relay drive module 4, a resistor control and adjustment module 5, and a resistor feedback module 6.

[0036] External interface 1 connects to the cabinet and is used for mechanical fixation, receiving electrical signals from the cabinet, and outputting resistance signals to the cabinet. The electrical signals include CAN physical signals. In one embodiment, the cabinet has a pull-out aid and a backplane, and external interface 1 includes a mechanical fixation interface and an electrical signal interface. In this embodiment, the mechanical fixation interface is a front-end baffle, which is fixed to the front end of the resistance simulation device. The front-end baffle connects to the resistance simulation device through fixing holes on the pull-out aid. The electrical signal interface is a rear-end electrical connector, which connects to the backplane and connects the output resistance signal of the resistance simulation device to the cabinet through the backplane. Furthermore, the front-end baffle is a standard 3U size, and the rear-end electrical connector is a Harding 96-pin right-angle male connector.

[0037] When installing the equipment, first determine the installation location, and then install the backplate at the rear of the cabinet according to the guide rails. The backplate connects to the resistance simulation equipment for automotive electrical function system integration testing according to an embodiment of the present invention via a Harding 96-pin female socket, and the back of the backplate has Weidmuller terminals. After the backplate is installed, insert the resistance simulation equipment, and use the pull-out tool to connect the equipment's Harding 96-pin bent male plug to the Harding 96-pin female socket on the backplate. The backplate connects the output resistance signal of the resistance simulation equipment to the cabinet via the Weidmuller terminals, and simultaneously connects the power supply and CAN control signals from the cabinet to the resistance simulation equipment. Secure the front panel and the cabinet with the fixing screws on the front panel to prevent the connection between the cabinet and the resistance simulation equipment from becoming loose.

[0038] The CAN bus transceiver module 2 is the communication interface for the resistor analog device. CAN bus transceiver module 2 converts the received CAN physical signals into digital signals and sends the digital signals to the microcontroller 3. In one embodiment, the CAN bus transceiver module 2 mainly includes a CAN transceiver module, which can bidirectionally convert the CAN bus physical differential voltage signals to digital signals and transmit the digital signals to the microcontroller. Preferably, in this embodiment, the CAN transceiver module uses a TJA1050. The CAN bus is one of the widely used fieldbuses in the field of industrial communication control. Using the CAN bus allows the device of this invention to be easily expanded and applied to any industrial equipment and system with a CAN interface, making it easy to expand.

[0039] The microcontroller 3 receives digital signals and parses CAN communication messages, identifies the status of the resistor control adjustment module 5 and the resistor feedback module 6, and controls the relay drive module 4.

[0040] The resistance control adjustment module 5 includes at least one discrete resistor array and a relay array for adjusting the theoretical output resistance value. In one embodiment, the schematic diagram of the resistance control adjustment module is as follows: Figure 2 As shown in the diagram, in the resistance control and adjustment module 5, a discrete resistor array consists of several discrete resistors connected in series. A relay is connected in parallel to each discrete resistor. By combining the opening and / or closing of multiple relays, the series connection of discrete resistors with different resistance values ​​is controlled to adjust the theoretical output resistance value. The relays are double-pole double-throw type, opening or closing two independent circuits. One circuit serves as the output resistance circuit, and the other as a shadow circuit. The shadow circuit has the same state as the output resistance circuit. When adjusting the theoretical output resistance, the output resistance circuit is connected to the resistance feedback module 6, and the shadow circuit is connected to an external circuit. In this embodiment, a discrete resistor array consists of 6 groups of 24 discrete resistors connected in series to form an output resistance circuit. Each group of resistors is assigned using a 1-2-3-4 numbering system, representing the ones, tens, hundreds, thousands, ten thousands, and hundred thousands place of the output resistance, respectively.

[0041] The resistance feedback module 6 is used to collect the actual resistance value at the output of the resistance simulation device used for automotive electrical function system integration testing. In one embodiment, the resistance feedback module 6 includes a constant current source circuit and a voltage acquisition circuit. The constant current generated by the constant current source circuit converts the resistance signal of the output resistance circuit into a voltage signal, which is then converted into a digital quantity by the voltage acquisition circuit and transmitted to the microcontroller for closed-loop control. Figure 3This is a schematic diagram of the resistance sampling module. In this preferred embodiment, the constant current source circuit includes a controllable precision voltage regulator TL431, a precision resistor, and a relay. The voltage acquisition circuit uses the AD7705 chip from Analog Devices (AD). The pin definitions and specifications of the chip can be found in the AD7705 microcontroller user manual. The TL431 voltage regulator provides a precise and stable 2.5V voltage. By controlling the relay to switch between different resistor values, the constant current source can provide four current levels: 2.5mA, 0.25mA, 25uA, and 2.5uA. The appropriate constant current level is selected based on the required resistance to generate a 0-3V voltage for the voltage acquisition circuit. The AD7705 chip is a 16-bit analog sampling chip with built-in front-end analog adjustment circuitry, a programmable digital filter, a modulator, and a programmable amplifier. The sampling results are transmitted to the microcontroller via SPI communication.

[0042] The relay driver module 4 is located between the microcontroller and the relay array and is used to drive the relays. In one embodiment, the relay driver module 4 includes a Darlington transistor to enhance the output drive capability of the microcontroller 3's I / O pins, converting the relay control commands output by the microcontroller 3 into current signals to drive the relays. Preferably, in this embodiment, the driver module 4 uses a ULN2003 chip.

[0043] In this embodiment, the microcontroller 3 issues control commands based on the difference between the theoretical output resistance value and the actual resistance value to control the relay drive module 4. In this embodiment, the state of the resistance control adjustment module 5 represents the theoretical output resistance value of the entire device, while the resistance value collected by the resistance feedback module 6 represents the actual resistance value of the entire device. The microcontroller 3 recalculates the relay control commands based on the error between the two, forming a closed-loop control that ensures the actual output resistance value is highly consistent with the set theoretical output resistance value. This reduces errors caused by conduction resistance and temperature drift, thereby significantly improving the output accuracy of the entire device. This embodiment preferably uses an STMicroelectronics STM32F103ZET7 microcontroller. The pin definitions and specifications of the microcontroller can be found in the STMicroelectronics STM32F103ZET7 microcontroller user manual. This model of microcontroller has 112 general-purpose I / O ports, providing sufficient resources to control the relay array of this invention.

[0044] An embodiment of the present invention provides a resistance simulation device for automotive electrical function system integration testing, which includes at least one resistance channel. Each resistance channel comprises an output resistance circuit and a resistance sampling module. The resistance sampling module in each resistance channel enables closed-loop dynamic control, thereby resolving errors caused by individual resistance differences and temperature drift, and significantly improving the accuracy of the output resistance. In one embodiment, each resistance channel can output any resistance value within the range of 0–1111.11 kΩ, with a resolution of 1 Ω.

[0045] In this preferred embodiment, a single resistance simulation device has a total of 4 channels. For example... Figure 2 As shown, the channel output pins are RESx_A and RESx_B, where x takes values ​​of 1, 2, 3, and 4. Each channel consists of 24 discrete resistors connected in series in 6 groups. Each group of discrete resistors is numbered 1-2-3-4 to represent the ones, tens, hundreds, thousands, ten thousands, and hundred thousands place of the output resistance, respectively. A relay is connected in parallel with each discrete resistor; this relay is open by default. When the relay is closed, the corresponding discrete resistor is short-circuited. Thus, by controlling different combinations of the 24 relays being open and / or closed, the series connection of discrete resistors with different resistance values ​​can be controlled, thereby adjusting the theoretical output resistance value of the corresponding channel. The relays are double-pole double-throw type, capable of opening or closing two independent circuits. One circuit acts as the output resistor circuit, and the other as a shadow circuit. The resistor between RESx_out_A and RESx_out_B acts as the output resistor circuit, and the resistor between REFLECTIONx_A and REFLECTIONx_B acts as the shadow circuit. (See [link to documentation]). Figure 2 As mentioned above, each circuit consists of 6 sets of resistors connected in series, as follows:

[0046] Units digit representation: Using 1 ohm, 2 ohm, 3 ohm, and 4 ohm resistors, represented in the diagram as 1R, 2R, 3R, and 4R, any value from 0 ohms to 9 ohms can be achieved through combinations of opening and / or closing relays.

[0047] Tens representation: Using 10 ohms, 20 ohms, 30 ohms, and 40 ohms resistors, represented in the diagram as 10R, 20R, 30R, and 40R, any integer tens value from 10 ohms to 90 ohms can be achieved by combining the opening and / or closing of relays. If all relays are closed, it can also represent 0 ohms.

[0048] Hundreds digit representation: Using 100 ohms, 200 ohms, 300 ohms, and 400 ohms resistors, represented in the diagram as 100R, 200R, 300R, and 400R, any integer hundreds resistance value from 100 ohms to 90 ohms can be achieved by combining the opening and / or closing of relays. If all relays are closed, it can also represent 0 ohms.

[0049] Thousands representation: Using 1k ohms, 2k ohms, 3k ohms, and 4k ohms resistors, represented as 1K, 2K, 3K, and 4K in the diagram, any integer thousands resistance value from 1k ohms to 9k ohms can be achieved by combining the opening and / or closing of relays. If all relays are closed, it can also represent 0 ohms.

[0050] Ten-thousands place representation: Using 10k ohms, 20k ohms, 30k ohms, and 40k ohms resistors, represented in the diagram as 10K, 20K, 30K, and 40K, any integer resistance value from 10k ohms to 90k ohms can be achieved by combining the opening and / or closing of relays. If all relays are closed, it can also represent 0 ohms.

[0051] 100,000 digit representation: Using 100k ohms, 200k ohms, 300k ohms, and 400k ohms resistors, represented in the diagram as 100K, 200K, 300K, and 400K, any integer value in the hundreds of thousands range from 100k ohms to 900k ohms can be achieved by combining the opening and / or closing of relays. If all relays are closed, it can also represent 0 ohms.

[0052] Theoretically, by connecting the above 6 sets of resistors in series and combining them with switches, it is possible to achieve continuous adjustment of any resistance value between 0 ohms and 1111.11k ohms, with an adjustment step of 1 ohm.

[0053] When the output resistance value needs to be updated, the microcontroller 3 first controls the Reflection_Switch relay to switch, and the channel output pins RESx_A and RESx_B switch from RESx_out_A and RESx_out_B to REFLECTIONx_A and REFLECTIONx_B, connecting the shadow circuit to the external circuit. This ensures that the output characteristics of the device are not affected during closed-loop adjustment and control of the resistor, while simultaneously disconnecting the output resistor circuit from the external circuit, ensuring the basic conditions for online resistance measurement. Then, the microcontroller 3 controls the Sensor_Switch relay to switch, and the Current_OUT and GND pins of the resistance feedback module 6 switch to RESx_out_A and RESx_out_B, connecting the output resistor circuit to the resistance feedback module 6 for closed-loop adjustment and control. In one embodiment, the relay is a G6SU-2F-Y-TR, a high-speed relay that ensures that all adjustment and switching processes do not affect the output characteristics of the device.

[0054] Figure 4 This is a software control flowchart of a resistor simulation device for automotive electrical function system integration testing according to an embodiment of the present invention.

[0055] Step S1: When the device is powered on, the microcontroller enters the initialization program, which mainly performs clock configuration, IO port configuration, interrupt configuration, AD sampling configuration, CAN module configuration, etc.

[0056] In step S2, the microcontroller enters standby mode and waits to receive CAN bus information.

[0057] Step S3: Determine whether valid CAN information has been identified. If yes, proceed to step S4; otherwise, return to step S2. Specifically: When the CAN bus transceiver module receives an external CAN physical signal, it converts the CAN physical signal into a digital signal and transmits the digital signal to the microcontroller. If the microcontroller identifies a valid CAN signal, proceed to step S4; otherwise, return to step S2.

[0058] Step S4: Enter the CAN interrupt routine. In the CAN interrupt routine, the microcontroller will extract the ID and data information.

[0059] Step S5: Compare the ID extracted in step S4 with the device address ID. If they are equal, the corresponding data information is a valid CAN message, and the process proceeds to step S6. Otherwise, return to the standby mode of step S2 and continue waiting for the next interrupt. The device address ID is set by a DIP switch located on the board inside the device, and the DIP switch value can be arbitrarily set by the user. This embodiment preferably incorporates an 8-bit DIP switch, thus allowing up to 256 devices (1024 resistor signals) to be integrated into a single system. The number of DIP switch bits can be increased according to actual needs to integrate a larger number of devices.

[0060] Step S6: Extract the resistor channel number and theoretical value of the resistor control signal from the valid CAN message. Specifically, when a valid CAN message is received, the microcontroller extracts 8 bytes of data information, where the 8th byte represents the resistor channel to be controlled, with a value range of 1-4; the 1st-3rd bytes represent the theoretical value of the resistor control signal.

[0061] Step S7: Determine whether the theoretical value of the resistance control signal extracted in step S6 is equal to the original theoretical value of the resistance control signal. If yes, return to step S2, the microcontroller ignores this CAN message, enters standby mode, and continues to wait for the next interrupt. If no, it means that the external control system has updated the requirement for the theoretical value of the resistance control signal, so proceed to step S8.

[0062] Step S8: Connect the shadow circuit to the external circuit, and simultaneously switch the output resistor circuit to the resistance feedback module. Specifically: The microcontroller first controls the Reflection_Switch relay to connect the shadow circuit to the external circuit, and then controls the Sensor_Switch relay to connect the output resistor circuit to the resistance feedback module.

[0063] Step S9: Adjust the theoretical output resistance value of the resistance control module and proceed to step S11.

[0064] In step S10, the resistance feedback module collects the actual resistance value of the entire device output terminal and proceeds to step S11.

[0065] Step S11: Determine whether the actual resistance value in step S10 is equal to the theoretical output resistance value in step S9. If not, proceed to step S12. If yes (or the theoretical value of the control signal is lower than the set threshold), it means that the device has successfully updated the resistance value, and proceed to step S13.

[0066] Step S12: Adjust the theoretical output resistance value to match the actual resistance value, and return to step S9.

[0067] In this embodiment, steps S9 to S12 specifically involve: the microcontroller recalculating the relay control command based on the error between the theoretical output resistance value and the actual resistance value, adjusting the theoretical output resistance value of the resistance control adjustment module to form a closed-loop dynamic control until the actual resistance value is equal to the theoretical output resistance value (or lower than the set threshold). This solves the error caused by individual resistance differences and temperature drift, thereby ensuring the output accuracy of the entire device.

[0068] Step S13: Switch the output resistor circuit back to the external circuit and disconnect the output resistor circuit from the resistance feedback module. Specifically: The microcontroller controls the Sensor_Switch relay to disconnect the output resistor circuit from the resistance feedback module, and then controls the Reflection_Switch relay to connect the output resistor circuit to the external circuit.

[0069] Step S14: Exit the interrupt and enter standby mode.

[0070] The beneficial effects of the resistance simulation device for automotive electrical function system integration testing of the present invention are as follows:

[0071] 1. This invention can be easily installed in the rack cabinet of an automotive electrical function system integration test bench.

[0072] 2. The single device of the present invention has 4 channels, each of which can be continuously adjusted between 0 ohms and 1111.11k ohms with an adjustment step of 1 ohm, resulting in high resolution and a wide adjustment range.

[0073] 3. Because it has a resistance feedback module, the present invention can realize online resistance measurement and form closed-loop control, thus greatly improving the accuracy of output resistance.

[0074] 4. This invention uses CAN bus communication, which can be easily integrated into any system with a CAN interface. It is easy to expand, easy to control, and meets the large demand for resistance simulation channels in automotive electrical function system integration testing.

[0075] It should be understood that the terms "front" and "rear" used in this invention to indicate orientation or positional relationship are only for the convenience of describing this invention and simplifying the description, and do not indicate that a specific orientation is required, or that it must be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0076] The above embodiments are merely further illustrations of the present invention and are not intended to limit the present invention in any other way. The present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but all such corresponding changes and modifications should fall within the protection scope of the present invention.

Claims

1. A resistance simulation device for automobile electrical function system integration test, installed in a cabinet of an automobile electrical function system integration test bench, characterized in that, The resistance simulation device comprises an external interface, a CAN bus transceiver module, a single-chip microcomputer, a relay driving module, a resistance control and adjustment module and a resistance back sampling module. The external interface is connected with the cabinet and is used for mechanical fixation, receiving electrical signals from the cabinet and outputting resistance signals to the cabinet. The CAN bus transceiver module converts the received CAN physical signals into digital signals and sends the digital signals to the single-chip microcomputer. The single-chip microcomputer receives the digital signals, analyzes CAN messages, identifies the states of the resistance control and adjustment module and the resistance back sampling module and controls the relay driving module. The resistance control and adjustment module comprises at least one discrete resistance array and a relay array and is used for adjusting a theoretical output resistance value. The relay driving module is located between the single-chip microcomputer and the relay array and is used for driving the relays. The resistance back sampling module is used for collecting actual resistance values at the output end of the resistance simulation device. The single-chip microcomputer sends a control instruction according to the difference between the theoretical output resistance value and the actual resistance value to control the relay driving module.

2. The resistance simulation device for testing automobile electrical function system integration according to claim 1, characterized in that, The cabinet is provided with a puller and a back plate. The external interface comprises a mechanical fixation interface and an electrical signal interface. The mechanical fixation interface is a front end baffle.

3. The resistance simulation device for testing automotive electrical function system integration according to claim 2, characterized in that, The front end baffle is provided at the front end of the resistance simulation device.

4. The resistance simulation device for testing automotive electrical function system integration according to claim 1, characterized in that, The front end baffle is connected with the cabinet through the fixation holes on the puller.

5. The resistance simulation device for testing automotive electrical function system integration according to claim 4, characterized in that, The electrical signal interface is a rear end electrical connector. The rear end electrical connector is connected with the back plate. The resistance simulation device is provided with at least one resistance channel. Each resistance channel is provided with an output resistance circuit and a resistance back sampling module. Each group of discrete resistors is assigned with one, two, three and four to represent the units, tens, hundreds, thousands and ten-thousands of the output resistance. The resistance simulation device is provided with at least one resistance channel. Each resistance channel is provided with an output resistance circuit and a resistance back sampling module.

6. The resistance simulation device for testing automotive electrical function system integration according to claim 5, characterized in that, Each resistance channel can output any resistance value in the range of 0-1111.11k ohms with a resolution of 1 ohm.

7. The resistance simulation device for testing automotive electrical function system integration according to claim 1, characterized in that, The relay drive module comprises a Darlington tube.

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