Fault testing device for input signal

Abstract

The utility model discloses a fault testing device for input signals, which relates to the field of fault testing, and is characterized in that three selection modules and a voltage testing device are arranged, and the first selection module is connected in series between an external input of an ECU and a first power supply; the input ends of the second selection module are connected with the external input ends of the ECU in a one-to-one correspondence mode, and the two output ends of the second selection module are grounded and connected with a second power source respectively. The input ends of the third selection module are connected with the input ends of the MCU in the ECU in a one-to-one correspondence mode, and the output ends of the third selection module are connected with the voltage testing device. Faults are injected into the external input end of the ECU through the first selection module and the second selection module, the voltage testing device is communicated with one input end of the MCU through the third selection module, so that the voltage testing device receives the voltage of the input end of the MCU, and the states of the input ends of the MCU in different fault tests are conveniently tested. Multi-port multi-fault testing can be realized without frequent plugging, and the use efficiency of the fault testing device is improved.

Description

Technical Field

[0001] The utility model relates to the field of fault testing, in particular to a fault testing device for an input signal. Background Art

[0002] The function of ECU (Electronic Control Unit) is to control the working state of the equipment and realize various functions. The main control logic of ECU is realized by the built-in MCU (Micro Controller Unit). ECU is usually used in automobiles, using various sensors and buses to collect various parameters and data related to automobile driving, so as to realize the control of automobile safe driving.

[0003] In order to ensure the effectiveness and reliability of the ECU, a fault test needs to be performed before the ECU is put into use. Specifically, it is necessary to test whether the input interface of the internal MCU can normally receive external input signals. Since multiple fault tests need to be performed, in the prior art, a fault test device is usually connected to the ECU, and the staff operates the fault test device to generate voltage signals required for different fault test items and inject them into the ECU. The voltage signals are transmitted to the MCU through the internal line of the ECU, and the input interface voltage of the MCU under different fault test items is tested in turn. It is determined whether the input interface of the MCU is normal based on the input interface voltage and the specified voltage of the corresponding fault test item.

[0004] However, since the fault testing device in the prior art can only test one interface at a time, and the MCU has multiple input interfaces, each input interface corresponds to an external input interface of the ECU. When the prior art tests all the input interfaces of the MCU, after testing one input interface of the MCU, it is necessary to unplug the fault testing device from an external input interface of the ECU and reconnect it to the next external input interface of the ECU. The use efficiency of such a fault testing device is very low, and it is difficult to carry out multi-interface and multi-fault testing projects. Utility Model Content

[0005] The utility model aims to provide a fault test device for input signals, which can realize multi-port multi-fault testing without frequent plugging and unplugging, thereby improving the use efficiency of the fault test device.

[0006] In order to solve the above technical problems, the utility model provides a fault testing device for input signals, which is characterized by comprising:

[0007] A first selection module, a second selection module, a third selection module and a voltage testing device;

[0008] The i-th input terminal of the first selection module is connected to the i-th output terminal of the first power supply, and the i-th output terminal of the first selection module is respectively connected to the i-th external input terminal of the ECU to be tested and the i-th input terminal of the second selection module; the first selection module is used to control the on-off state between each of the i-th output terminals and the corresponding i-th input terminals according to the fault test instruction;

[0009] The first output end of the second selection module is connected to the second power supply, the second output end of the second selection module is grounded, and the second selection module is used to control the on-off state between each input end and the two output ends according to the fault test instruction;

[0010] The i-th input terminal of the third selection module is connected to the i-th input terminal of the MCU to be tested in the ECU to be tested, the output terminal of the third selection module is connected to the input terminal of the voltage testing device, and the third selection module is used to control one of the input terminals to be connected to the output terminal according to the fault test instruction;

[0011] The voltage testing device is used to test the voltage;

[0012] Wherein, i is any positive integer not greater than the number of input ports of the MCU to be tested.

[0013] On the one hand, the first selection module includes:

[0014] N input control switches and a first controller, where N is equal to the number of input ports of the MCU to be tested;

[0015] The first end of the i-th input control switch is connected to the i-th output end of the first power supply, and the second end of the i-th input control switch is respectively connected to the i-th external input end of the ECU to be tested and the i-th input end of the second selection module;

[0016] The N control terminals of the first controller are respectively connected to the control terminals of the N input control switches, and the first controller is used to control the on-off states of the N input control switches according to the fault test instruction.

[0017] On the one hand, the third selection module includes:

[0018] P test control switches and a third controller, where P is equal to the number of input ports of the MCU to be tested;

[0019] The first end of the i-th test control switch is connected to the i-th input end of the MCU to be tested, and the second ends of P test control switches are all connected to the input end of the voltage testing device;

[0020] The P control ends of the third controller are respectively connected to the control ends of the P test control switches, and the third controller is used for controlling the on-off states of the P test control switches according to the fault test instruction.

[0021] On the one hand, the test control switch is a relay;

[0022] The first end of the normally open contact of the i-th relay is connected to the i-th input terminal of the MCU to be tested, and the second end of the open contact of the i-th relay is connected to the input terminal of the voltage testing device;

[0023] The coil of the i-th relay is connected to the i-th control terminal of the third controller.

[0024] On the one hand, it also includes the test host;

[0025] The test host is connected to the voltage detection device, and the test host is used to display the voltage value obtained by the voltage detection device.

[0026] On the one hand, it also includes a communication module;

[0027] One end of the communication module is connected to the control instruction output end of the test host, and the other end of the communication module is connected to the control instruction input ends of the first selection module, the second selection module and the third selection module respectively;

[0028] The communication module is used to send the fault test instruction.

[0029] On the one hand, the communication module is a CAN communication module.

[0030] On the one hand, the second selection module includes:

[0031] M short-circuit control switches, a first single-pole double-throw switch, a second single-pole double-throw switch, and a second controller, where M is equal to the number of input ports of the MCU to be tested;

[0032] The first end of the i-th short-circuit control switch is respectively connected to the i-th output end of the first selection module and the i-th external input end of the ECU to be tested, and the second ends of the M short-circuit control switches are all connected to the fixed end of the first single-pole double-throw switch;

[0033] The first moving end of the first single-pole double-throw switch is grounded, and the second moving end of the first single-pole double-throw switch is connected to the fixed end of the second single-pole double-throw switch; the first moving end of the second single-pole double-throw switch is suspended, and the second moving end of the second single-pole double-throw switch is connected to the second power supply;

[0034] The M+2 control ends of the second controller are respectively connected to the control ends of the M short-circuit control switches, the first single-pole double-throw switch and the second single-pole double-throw switch, and the second controller is used to control the on and off states of the M short-circuit control switches, the first single-pole double-throw switch and the second single-pole double-throw switch according to the fault test instruction.

[0035] The beneficial effect of the present application is that a fault test device for input signals is provided, by setting three selection modules and a voltage test device, the first selection module is connected in series between the external input of the ECU and the first power supply; each input end of the second selection module is connected to each external input end of the ECU in a one-to-one correspondence, and the two output ends are grounded and connected to the second power supply respectively; each input end of the third selection module is connected to each input end of the MCU inside the ECU in a one-to-one correspondence, and the output end is connected to the voltage test device. The fault injection state of each external input end of the ECU is determined by the first selection module and the second selection module, and the specified input end voltage of the MCU inside the ECU is selected by the third selection module to be sent to the voltage test device, so that the voltage test device can receive the voltage values ​​of each input end of the MCU in different fault test scenarios, and there is no need to frequently plug and unplug the fault test device, which improves the use efficiency of the fault test device and can be effectively applied in multi-port multi-fault test projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the prior art and the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0037] Figure 1 A schematic diagram of the structure of a fault testing device for an input signal provided in the present application;

[0038] Figure 2 A schematic structural diagram of another input signal fault testing device provided in the present application. DETAILED DESCRIPTION

[0039] The core of the utility model is to provide a fault test device for input signals, which can realize multi-port multi-fault testing without frequent plugging and unplugging, thereby improving the use efficiency of the fault test device.

[0040] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0041] When testing the MCU in the ECU, the VT (Vehicle Testing) test system is usually used for testing, which is mainly used to simulate the performance of the ECU during the actual driving of the vehicle. The VT test system can provide a simulated real vehicle operating environment for the ECU to test. The VT test system usually needs to test 5 types of faults, namely, the fault of the input terminal shorted to the ground, the fault of the input terminal shorted to the power supply, the fault of the input line shorted between two adjacent input terminals, the voltage fault when there is no external load, and the voltage fault when there is an external load. These different faults can detect the corresponding voltage value at the port of the MCU (for example, when shorted to the ground, the port voltage should be 0).

[0042] In the existing fault testing technology, it is generally implemented by using a fault testing device specially used for testing. The staff connects the fault testing device to the external input terminal of the ECU corresponding to the input terminal of the MCU, and performs manual operation and command input on the fault testing device to make the fault testing device inject the above fault into the MCU, and at the same time uses a voltage testing device to detect the input terminal voltage of the MCU, thereby realizing the fault test. However, because there are many input terminals on the MCU, the fault testing device can usually only test one input terminal at the same time. When it is necessary to perform a fault test on each input terminal on the MCU, each input terminal needs to be manually tested 5 times, and after testing one interface, it is necessary to manually disconnect the fault testing device and connect it to another external input terminal on the ECU, and then manually inject 5 types of faults into the other external input terminal, and so on until each input terminal is tested. This method takes a long time and the testing efficiency is very low.

[0043] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a fault testing device for an input signal provided in the present application includes:

[0044] A first selection module 1, a second selection module 2, a third selection module 3 and a voltage testing device 4;

[0045] The i-th input terminal of the first selection module 1 is connected to the i-th output terminal of the first power supply, and the i-th output terminal of the first selection module 1 is respectively connected to the i-th external input terminal of the ECU to be tested and the i-th input terminal of the second selection module 2; the first selection module 1 is used to control the on-off state between each i-th output terminal and the corresponding i-th input terminal according to the fault test instruction;

[0046] The first output terminal of the second selection module 2 is connected to the second power supply 5, the second output terminal of the second selection module 2 is grounded, and the second selection module 2 is used to control the on-off state between each input terminal and the two output terminals according to the fault test instruction;

[0047] The i-th input terminal of the third selection module 3 is connected to the i-th input terminal of the MCU to be tested in the ECU to be tested, the output terminal of the third selection module 3 is connected to the input terminal of the voltage test device 4, and the third selection module 3 is used to control one of the input terminals to be connected to the output terminal according to the fault test instruction;

[0048] The voltage testing device 4 is used to test the voltage;

[0049] Wherein, i is any positive integer not greater than the number of input ports of the MCU to be tested.

[0050] In order to improve the test efficiency, in the present application, the first selection module 1 is used to determine whether the external input terminals of the ECU are connected to an external load (that is, an external power supply or other device), the second selection module 2 is used to determine whether the external input terminals of the ECU are short-circuited and to which position, and the third selection module 3 is used to determine which input terminal voltage of the MCU needs to be tested.

[0051] Specifically, considering that the short circuit of the input lines of two adjacent input terminals will affect the result of the fault test on a single input terminal, for example, when the A input terminal needs to be short-circuited to the ground, if the adjacent B input terminal is also undergoing other tests, and the input lines of the AB input terminals are also short-circuited, it may cause the voltage value finally measured at the A input terminal to not meet the short-circuited to the ground test voltage, thereby misjudging the short-circuited to the ground fault at the A input terminal. Therefore, the test method of the present application is the same as the prior art, and only one input terminal is tested at the same time, and the next input terminal is tested after the test of one input terminal is completed.

[0052] According to the operation of the staff, the fault test instruction will indicate which input terminal needs to be tested this time. For the first selection module 1, the on-off state between the input terminal to be tested and its corresponding output terminal is determined according to the fault test instruction, and all other input terminals and their corresponding output terminals are disconnected to avoid other input terminals interfering with the test results of the input terminal to be tested. According to the five fault test items mentioned above, when performing the two tests of voltage fault in the presence of external load and short-circuit fault of input lines of two adjacent input terminals, the input terminal to be tested on the first selection module 1 can be connected to its corresponding output terminal; and when performing the other three fault tests, it can be disconnected.

[0053] For the second selection module 2, according to the fault test instruction, the input terminal to be tested is controlled to be connected to a certain output terminal, and all other input terminals are disconnected from the two output terminals to avoid other input terminals interfering with the test results of the input terminal to be tested. When the input terminal is shorted to the ground, the input terminal to be tested is connected to the second output terminal; when the input terminal is shorted to the power supply, the input terminal to be tested is connected to the first output terminal; and when the other three faults are performed, no input terminal is connected, that is, at this time, all input terminals in the second selection module 2 are disconnected from the two output terminals to avoid introducing short-circuit faults in other fault items.

[0054] For the third selection module 3, it is mainly to facilitate the voltage testing device 4 to perform voltage testing. According to the fault detection instruction, it is determined which input terminal on the MCU needs to be tested, and then the input terminal of the third selection module 3 connected to the input terminal is controlled to be connected with its corresponding output terminal, and all other input terminals and output terminals are disconnected. In this way, the voltage of the output terminal to be tested on the MCU can be input into the voltage testing device 4 through the third selection module 3, thereby realizing fault testing.

[0055] For a clear description of the above, please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a fault testing device for an input signal provided in the present application, and an actual example is used as an illustration.

[0056] Assume that the MCU has 12 input terminals INPUT i (i=1-12) to be tested, and there are 12 external input terminals IN i (1=1-12) on the ECU accordingly. The first and third selection modules 3 also have 12 input terminals and output terminals respectively, and the second selection module 2 has 12 input terminals and 2 output terminals. If INPUT1 needs to be tested this time, assuming that the test flow of the fault test instruction is voltage fault when there is no external load -> voltage fault when there is an external load -> input terminal short-to-ground fault -> input terminal short-to-power fault -> input line short-circuited fault of two adjacent input terminals, the order is as follows:

[0057] When performing a voltage fault test when there is no external load, the line between the 1st input terminal and the 1st output terminal of the first selection module 1 is disconnected (of course, the lines between the 2nd to 12th input terminals and the corresponding 2nd to 12th output terminals should also remain disconnected), all input terminals of the second selection module 2 are disconnected, and the line between the 1st input terminal and the 1st output terminal of the third selection module 3 is connected (and the lines between the 2nd to 12th input terminals and the corresponding 2nd to 12th output terminals should also remain disconnected). At this time, the voltage at INPUT1 will be equal to the default voltage value provided by the ECU itself to the MCU under normal circumstances. If the voltage at INPUT1 is similar to or equal to the default voltage value when there is no external load, it can be said that there is no voltage fault in INPUT1 when there is no external load.

[0058] When performing a voltage fault test when an external load is present, the line between the first input terminal and the first output terminal of the first selection module 1 is connected, all input terminals of the second selection module 2 are disconnected, and the line between the first input terminal and the first output terminal of the third selection module 3 is connected. At this time, the voltage output from the first output terminal of the external load (first power supply) can reach INPUT1 through IN1, and is tested by the voltage testing device. If the voltage at INPUT1 meets the voltage requirement when an external load is present, it can be said that INPUT1 has no voltage fault when an external load is present.

[0059] When performing a fault test of input short-to-ground, all inputs of the first selection module 1 are disconnected, the first input of the second selection module 2 is connected to the second output (other inputs are not connected to any input), and the line between the first input and the first output of the third selection module 3 is connected. At this time, INPUT1 is grounded via IN1, and is tested by a voltage test device. If the voltage at INPUT1 meets the voltage requirement when the input is grounded, it means that the short-to-ground fault of INPUT1 can be detected normally.

[0060] When performing a fault test of the input terminal being shorted to the power supply, all input terminals of the first selection module 1 are disconnected, the first input terminal of the second selection module 2 is connected to the first output terminal, and the line between the first input terminal and the first output terminal of the third selection module 3 is connected. At this time, INPUT1 is connected to the second power supply 5 via IN1, and is tested by the voltage testing device. If the voltage at INPUT1 meets the voltage requirement when the input is connected to the power supply, it can be said that the fault of INPUT1 being shorted to the power supply can be detected normally.

[0061] Finally, when performing a fault test of short-circuiting the input lines of two adjacent input terminals, the line between the first input terminal and the first output terminal of the first selection module 1 is connected, and the line between the second input terminal and the second output terminal is also connected, all input terminals of the second selection module 2 are disconnected, and the line between the first input terminal and the first output terminal of the third selection module 3 is connected. According to the above content, if there is no fault of short-circuiting adjacent lines, the voltage value detected by the voltage test device at this time should be equal to the voltage value of INPUT1 when there is no voltage fault when there is an external load, but if the input lines of INPUT1 and INPUT1 are short-circuited, or the input lines of IN1 and IN2 are short-circuited, the voltage value detected by the voltage test device may change, and whether there is a fault of short-circuiting adjacent lines is detected in this way.

[0062] In addition, when setting the fault test instructions, the staff can customize the test order of each input terminal of the MCU, as well as the test order of various fault tests of one input terminal, for example, first perform five tests on the INPUT1 of the MCU, then perform five fault tests on the INPUT2 of the MCU, and so on until the INPUT12 of the MCU. In this way, the automated test of multiple faults of multiple input terminals of the MCU can be realized, without the need for the staff to manually operate each fault test, nor the need for the staff to frequently unplug and plug in the fault test device, which significantly improves the test efficiency and shortens the test time.

[0063] In summary, by setting three selection modules and a voltage test device 4, the first selection module 1 is connected in series between the external input of the ECU and the first power supply; each input end of the second selection module 2 is connected to each external input end of the ECU in a one-to-one correspondence, and the two output ends are respectively connected to the ground and the second power supply 5; each input end of the third selection module 3 is connected to each input end of the MCU inside the ECU in a one-to-one correspondence, and the output end is connected to the voltage test device. The connectivity status of each external input end of the ECU is determined by the first selection module 1 and the second selection module 2, and the specified input end voltage of the MCU inside the ECU is selected by the third selection module 3 to be sent to the voltage test device, so that the voltage test device can receive the voltage values ​​of each input end of the MCU in different fault test scenarios, and there is no need to frequently plug and unplug the fault test device, which improves the use efficiency of the fault test device and can be effectively applied in multi-port multi-fault test projects.

[0064] Based on the above embodiments:

[0065] In some embodiments, the first selection module 1 includes:

[0066] N input control switches and a first controller, where N is equal to the number of input ports of the MCU to be tested;

[0067] A first end of the i-th input control switch is connected to the i-th output end of the first power supply, and a second end of the i-th input control switch is connected to the i-th external input end of the ECU to be tested and the i-th input end of the second selection module 2 respectively;

[0068] The N control terminals of the first controller are connected to the control terminals of the N input control switches respectively, and the first controller is used to control the on-off states of the N input control switches according to the fault test instruction.

[0069] In order to simply implement the function of the first selection module 1, in this application, please refer to Figure 1 , Figure 1 This is a structural diagram of a fault test device for an input signal provided by the present application. The first selection module 1 is mainly composed of multiple switches and a controller. These input control switches are arranged one by one between the external load (first power supply) and the external input IN of the ECU, that is, each external input terminal IN i of the ECU is connected in series with an input control switch, and the first controller controls the on and off of these switches.

[0070] When it is necessary to test a certain input terminal INPUT i of the MCU, because the external inputs IN of the ECU correspond one to one with the input INPUTs of the MCU, the first controller can determine which input control switch is the switch corresponding to the input terminal that the MCU needs to test according to the fault test instruction, and at the same time control all other input control switches to be disconnected.

[0071] In combination with the five fault tests in the above embodiments, taking the need to perform a fault test on INPUT1 as an example, when performing a voltage fault test when an external load is present, the first input control switch of the first selection module 1 needs to be closed, and the other input control switches are disconnected; when performing a fault test of short-circuiting the input lines of adjacent input terminals, the first input control switch and the second input control switch of the first selection module 1 need to be closed, and the other input control switches are disconnected; when performing the other three fault tests, all input control switches in the first selection module 1 are disconnected.

[0072] It should be noted that the specific method of controlling the on-off of the switch in the present application is the same as the prior art. The present application mainly uses this structure to automatically implement a multi-port multi-fault testing process without the need for frequent plugging and unplugging of the fault testing device, and does not limit the method of how to achieve on-off control of the switch.

[0073] Through the above-mentioned structure, the function of the first selection module 1 can be realized simply and effectively.

[0074] In some embodiments, the third selection module 3 includes:

[0075] P test control switches and a third controller, where P is equal to the number of input ports of the MCU to be tested;

[0076] The first end of the i-th test control switch is connected to the i-th input end of the MCU to be tested, and the second ends of the P test control switches are all connected to the input end of the voltage test device 4;

[0077] The P control terminals of the third controller are respectively connected to the control terminals of the P test control switches, and the third controller is used to control the on-off states of the P test control switches according to the fault test instructions.

[0078] In order to simply implement the function of the third selection module 3, in this application, please refer to Figure 1 , Figure 1A structural diagram of a fault test device for an input signal provided in the present application, the third selection module 3 is also composed of multiple switches and a controller. One end of each switch is connected to each input end of the MCU in a one-to-one correspondence, and the other ends are connected together, and the common end of the connection is connected to the input end of the voltage test device. When the third controller implements the control, according to the fault detection instruction, which input end of the MCU needs to be tested will correspondingly control the test control switch connected to the input end to be tested to be turned on, and at the same time ensure that all other test control switches are disconnected, so that the input end voltage of the MCU can flow into the voltage test device through the test control switch, thereby realizing the voltage test.

[0079] Through the above structure, the function of the third selection module 3 can be realized simply and effectively.

[0080] In some embodiments, the test control switch is a relay;

[0081] The first end of the normally open contact of the i-th relay is connected to the i-th input terminal of the MCU to be tested, and the second end of the open contact of the i-th relay is connected to the input terminal of the voltage test device 4;

[0082] The coil of the i-th relay is connected to the i-th control terminal of the third controller.

[0083] In order to achieve safety control, in this application, relays are used as switches, that is, in addition to the various test control switches in the third selection module 3, the various short-circuit control switches in the second selection module 2 and the various input control switches in the first selection module 1 are all implemented by relays. This is because the switch itself also has a certain internal resistance. If the internal resistance is too large, it may affect the final test result of the voltage test device 4. By using a relay with a very small internal resistance, the impact of the internal resistance on the voltage can be reduced as much as possible, ensuring the accuracy of the test.

[0084] In addition, in some test situations, the current and voltage passed into the MCU input terminal may be large, and the method of controlling the gain and loss of power of the relay coil to realize the on-off of the switch achieves the purpose of using a small current to control a large current, ensuring the safety of the controller. In addition to using relays, this application can also be implemented using thyristors, that is, the anode and cathode of the thyristor are used as the two ends of the switch, and the gate is connected to the controller.

[0085] In some embodiments, a test host is also included;

[0086] The test host is connected to the voltage test device, and the test host is used to display the voltage value obtained by the voltage test device.

[0087] In order to facilitate operation and testing, a test host is also provided in this application. The test host is usually a computer or a console as a master control device. The staff can complete the test items they want by writing the scripts required for fault testing on the test host and sending them to each selection module through the test host. The main purpose of the test host is to collect the signals detected by the voltage test device and display them for easy viewing by the staff.

[0088] It should be noted that the script required for fault testing and how the test host displays the voltage value are not the protection content of this application. The technical means adopted belong to the existing technology. This application mainly protects the test host added to the entire fault testing device.

[0089] In some embodiments, further comprising a communication module;

[0090] One end of the communication module is connected to the control instruction output end of the test host, and the other end of the communication module is connected to the control instruction input ends of the first selection module 1, the second selection module 2 and the third selection module 3 respectively;

[0091] The communication module is used to send fault test instructions.

[0092] The communication module is a CAN communication module.

[0093] In order to achieve effective control, in this application, a CAN (Controller Area Network) communication module is used to realize the communication between the test host and the three control modules. Specifically, an error detection mechanism for data errors (such as cyclic redundancy check, frame check, error counter, etc.) is set in the CAN protocol. When an error occurs in the instruction sent by the test host to the selection module, the CAN communication module can instantly detect and mark the error in the transmission, so that the staff can be informed of the instruction abnormality, avoid erroneous fault testing, and ensure the reliability of fault testing.

[0094] In the actual device configuration, please refer to Figure 2 , Figure 2A schematic diagram of the structure of another fault test device for input signal provided in the present application. The entire VT test system of the present application is mainly composed of three groups of relays (relays, namely the first control module, the second control module and the third control module) and a voltage test device Voltage IN / OUT. It also includes a supply for powering the ECU during fault testing. The supply is not equivalent to an external load, and its purpose is to maintain the power on of the ECU. When performing a fault test, the staff can operate on the test host PC to issue various operation instructions, and issue them to the ECU through the CAN communication module, and the instructions are issued to each relay through the ECU; in addition, the VTtest system and the test host also communicate through ETH (Ethernet) to upload the voltage value tested by the voltage test device to the test host.

[0095] It should be noted that the voltage testing device Voltage IN / OUT used can be a device that can not only detect the input voltage but also provide voltage to other devices, such as a power management device with bidirectional function or a programmable power supply, etc. This device can not only detect the specific value of the input voltage, but also provide voltage to other devices. When it is used in the present application, it can be used as a voltage testing device and a second power supply at the same time, that is, the input end of the device is connected to the output end of the third selection module, and the output end of the device is connected to the second output end of the second selection module. In this way, only one device is needed to realize both voltage testing and power supply functions, saving economic costs and device volume.

[0096] In some embodiments, the second selection module 2 includes:

[0097] M short-circuit control switches, a first single-pole double-throw switch, a second single-pole double-throw switch, and a second controller, where M is equal to the number of input ports of the MCU to be tested;

[0098] The first end of the i-th short-circuit control switch is respectively connected to the i-th output end of the first selection module 1 and the i-th external input end of the ECU to be tested, and the second ends of the M short-circuit control switches are all connected to the fixed end of the first single-pole double-throw switch;

[0099] The first moving end of the first single-pole double-throw switch is grounded, and the second moving end of the first single-pole double-throw switch is connected to the fixed end of the second single-pole double-throw switch; the first moving end of the second single-pole double-throw switch is suspended, and the second moving end of the second single-pole double-throw switch is connected to the second power supply 5;

[0100] The M+2 control ends of the second controller are respectively connected to the control ends of the M short-circuit control switches, the first single-pole double-throw switch and the second single-pole double-throw switch. The second controller is used to control the on and off states of the M short-circuit control switches, the first single-pole double-throw switch and the second single-pole double-throw switch according to the fault test instructions.

[0101] In order to simply realize the function of the second selection module 2, in this application, the second selection module 2 is also mainly composed of a plurality of short-circuit control switches having the same number as the MCU input terminals, two switches for selecting outputs, and a controller. These short-circuit control switches are connected one by one with each external input terminal of the ECU, that is, each external input terminal of the ECU is connected in series with an input control switch, and the second controller controls the on and off of these short-circuit control switches.

[0102] In combination with the above embodiments, it can be seen that when it is necessary to test a certain input terminal of the MCU, the second controller can determine which short-circuit control switch is the short-circuit control switch required for the test according to the fault test instruction, and control all other short-circuit control switches to be disconnected; and, according to the fault test instruction, when the short-circuit control switch required for the test is closed, by controlling the connection direction of the two single-pole double-throw switches, it is determined which output terminal the short-circuit control switch required for the test is connected to.

[0103] Combined with the five fault tests, only when a short-to-ground or short-to-power test is required, a short-circuit control switch will be closed, and the other three tests require that all short-circuit control switches in the second selection module 2 are opened. Taking the need to perform a fault test on INPUT1 as an example, when performing a short-to-ground fault test, the first short-circuit control switch needs to be closed, and the other short-circuit control switches are all disconnected, and the fixed end of the first single-pole double-throw switch is connected to the first moving end, so that INPUT1 is grounded after passing through the external input IN1 of the ECU, the first short-circuit control switch and the first single-pole double-throw switch, thereby realizing a short-to-ground fault test; when performing a short-to-power supply fault test, the first short-circuit control switch is closed, and the other short-circuit control switches are all disconnected, the fixed end of the first single-pole double-throw switch is connected to the second moving end (that is, connected to the fixed end of the second single-pole double-throw switch), and the fixed end of the second single-pole double-throw switch is then connected to the second moving end, so that INPUT1 is connected to the second power supply 5 after passing through the external input IN1 of the ECU, the first short-circuit control switch, the first single-pole double-throw switch and the first single-pole double-throw switch, thereby realizing a short-to-power supply fault test.

[0104] Through the above-mentioned structure, the function of the second selection module 2 can be realized simply and effectively.

[0105] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present utility model.

[0106] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A fault testing device for an input signal, characterized in that: include: A first selection module, a second selection module, a third selection module and a voltage testing device; The i-th input terminal of the first selection module is connected to the i-th output terminal of the first power supply, and the i-th output terminal of the first selection module is respectively connected to the i-th external input terminal of the ECU to be tested and the i-th input terminal of the second selection module; The first selection module is used to control the on / off state between each of the i-th output terminals and the corresponding i-th input terminals according to the fault test instruction; The first output end of the second selection module is connected to the second power supply, the second output end of the second selection module is grounded, and the second selection module is used to control the on-off state between each input end and the two output ends according to the fault test instruction; The i-th input terminal of the third selection module is connected to the i-th input terminal of the MCU to be tested in the ECU to be tested, the output terminal of the third selection module is connected to the input terminal of the voltage testing device, and the third selection module is used to control one of the input terminals to be connected to the output terminal according to the fault test instruction; The voltage testing device is used to test the voltage; Wherein, i is any positive integer not greater than the number of input ports of the MCU to be tested.

2. The input signal fault testing device according to claim 1, characterized in that: The first selection module comprises: N input control switches and a first controller, where N is equal to the number of input ports of the MCU to be tested; The first end of the i-th input control switch is connected to the i-th output end of the first power supply, and the second end of the i-th input control switch is respectively connected to the i-th external input end of the ECU to be tested and the i-th input end of the second selection module; The N control terminals of the first controller are respectively connected to the control terminals of the N input control switches, and the first controller is used to control the on-off states of the N input control switches according to the fault test instruction.

3. The fault testing device for input signal according to claim 1, characterized in that: The third selection module includes: P test control switches and a third controller, where P is equal to the number of input ports of the MCU to be tested; The first end of the i-th test control switch is connected to the i-th input end of the MCU to be tested, and the second ends of P test control switches are all connected to the input end of the voltage testing device; The P control ends of the third controller are respectively connected to the control ends of the P test control switches, and the third controller is used for controlling the on-off states of the P test control switches according to the fault test instruction.

4. The input signal fault testing device as claimed in claim 3, characterized in that: The test control switch is a relay; The first end of the normally open contact of the i-th relay is connected to the i-th input terminal of the MCU to be tested, and the second end of the open contact of the i-th relay is connected to the input terminal of the voltage testing device; The coil of the i-th relay is connected to the i-th control terminal of the third controller.

5. The input signal fault testing device according to claim 1, characterized in that: Also includes test hosts; The test host is connected to a voltage detection device, and the test host is used to display a voltage value obtained by the voltage detection device.

6. The input signal fault testing device according to claim 5, characterized in that: Also includes a communication module; One end of the communication module is connected to the control instruction output end of the test host, and the other end of the communication module is connected to the control instruction input ends of the first selection module, the second selection module and the third selection module respectively; The communication module is used to send the fault test instruction.

7. The input signal fault testing device according to claim 6, characterized in that: The communication module is a CAN communication module.

8. The input signal fault testing device according to any one of claims 1 to 7, characterized in that: The second selection module comprises: M short-circuit control switches, a first single-pole double-throw switch, a second single-pole double-throw switch, and a second controller, where M is equal to the number of input ports of the MCU to be tested; The first end of the i-th short-circuit control switch is respectively connected to the i-th output end of the first selection module and the i-th external input end of the ECU to be tested, and the second ends of the M short-circuit control switches are all connected to the fixed end of the first single-pole double-throw switch; The first moving end of the first single-pole double-throw switch is grounded, and the second moving end of the first single-pole double-throw switch is connected to the fixed end of the second single-pole double-throw switch; the first moving end of the second single-pole double-throw switch is suspended, and the second moving end of the second single-pole double-throw switch is connected to the second power supply; The M+2 control ends of the second controller are respectively connected to the control ends of the M short-circuit control switches, the first single-pole double-throw switch and the second single-pole double-throw switch, and the second controller is used to control the on and off states of the M short-circuit control switches, the first single-pole double-throw switch and the second single-pole double-throw switch according to the fault test instruction.

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