Digital signal circuit, board card and system for hardware-in-loop test system

Abstract

The invention relates to a digital signal circuit, a board card and a system for a hardware-in-the-loop test system, an input signal processing module and an output signal processing module are integrated on the same printed circuit board, so that the number of board cards required by an in-the-loop test and the connection complexity are reduced; the input signal processing module and the output signal processing module are respectively arranged on different layers of the printed circuit board, input signals and output signals are respectively transmitted through the different layers of the printed circuit board, signal transmission directions do not need to be switched through a dial switch, errors and inconvenience caused by manual operation are avoided, the operation process is simplified, and the operation efficiency is improved. The test efficiency is improved; according to the digital signal circuit, an electromagnetic shielding layer connected with a fixed potential is arranged between the input signal processing module and the output signal processing module, so that electromagnetic interference between the input signal processing module and the output signal processing module is shielded, and interference between an input signal and an output signal can be reduced; and the accuracy and the stability of signal transmission are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle-mounted signal testing, in particular to a digital signal circuit, a board card and a system for a hardware-in-the-loop test system. BACKGROUND

[0002] At present, in the field of vehicle-mounted testing, HIL (Hardware-in-the-loop) testing is a widely used technology. The HIL test usually adopts a NI chassis and a test board card group; the NI chassis is used to simulate a vehicle-mounted device or a vehicle-mounted electrical system and can output corresponding state signals, and the test board card group is used to transmit various signals between the NI chassis and an ECU (Electronic Control Unit) of the vehicle-mounted device. The NI chassis is a chassis produced by the National Instruments (NI) company for integrating and managing various modular instruments and data acquisition devices.

[0003] The interaction between the NI chassis and the ECU involves both digital signals and analog signals; for the interaction process of the digital signals, the voltage ranges of the digital signals corresponding to the NI chassis and the ECU are different; this requires the digital processing module in the test board card group to be able to implement corresponding processing on the digital signals interacted between the NI chassis and the ECU, so that the NI chassis and the ECU can both receive signals within their voltage acquisition ranges. However, due to the complex environment in the vehicle-mounted test environment, there may be many interference factors, which may cause overvoltage or overcurrent in the circuit, which will seriously affect the quality of the digital signals.

[0004] Therefore, how to improve the stability of the digital signals in the HIL test process is a problem that needs to be solved. SUMMARY

[0005] Therefore, it is necessary to provide a digital signal circuit, a board card and a system for a hardware-in-the-loop test system to solve the problems in the prior art.

[0006] In a first aspect, the present application provides a digital signal circuit for a hardware-in-the-loop test system, the digital signal circuit comprising:

[0007] an input signal processing module configured to receive an initial input signal of a first object device and process the initial input signal into a target input signal and send the target input signal to a second object device;

[0008] an output signal processing module configured to receive an initial output signal of the second object device and process the initial output signal into a target output signal and send the target output signal to the first object device;

[0009] The digital signal circuit is integrated on a printed circuit board, and the printed circuit board comprises a first layer, a second layer, a third layer and a fourth layer which are sequentially stacked;

[0010] One of the input signal processing module and the output signal processing module is arranged on the first layer, and the other is arranged on the fourth layer; the second layer is connected to a fixed potential, and the second layer is used for shielding electromagnetic interference between the input signal processing module and the output signal processing module; the third layer is a power supply layer, and the power supply layer is used for supplying power to the input signal processing module and the output signal processing module respectively.

[0011] In one of the embodiments, the second layer is a whole metal layer, and the metal layer is grounded.

[0012] In one of the embodiments, the third layer comprises:

[0013] A first power supply module is connected to the input signal processing module and used for supplying power to the input signal processing module;

[0014] A second power supply module is connected to the output signal processing module and used for supplying power to the output signal processing module;

[0015] An isolation module is arranged between the first power supply module and the second power supply module, and the isolation module is used for isolating electromagnetic interference between the first power supply module and the second power supply module.

[0016] In one of the embodiments, the isolation module comprises a magnetic bead or an inductor.

[0017] In one of the embodiments, the input signal processing module comprises:

[0018] A signal input circuit, an input end of the signal input circuit is connected to the first object device, and an output end of the signal input circuit is connected to the second object device;

[0019] An input protection circuit is connected to an input end of the signal buffer circuit, and the input protection circuit is used for limiting voltage and current of the initial input signal; the input protection circuit comprises a current-limiting resistor and a voltage stabilizing diode; the current-limiting resistor is arranged at the input end of the signal buffer circuit, the anode of the voltage stabilizing diode is connected to a fixed potential, and the cathode of the voltage stabilizing diode is connected to the input end of the signal buffer circuit.

[0020] In one of the embodiments, the output signal processing module comprises:

[0021] A signal driving circuit, an input end of the signal driving circuit is connected to the first object device, and an output end of the signal input circuit is connected to the second object device;

[0022] An output filter circuit is connected to an output end of the signal driving circuit, and is used to filter high-frequency noise in the target output signal.

[0023] In one of the embodiments, an input end of the signal driving circuit is further connected with a first voltage dividing resistor and a second voltage dividing resistor.

[0024] In one of the embodiments, the first object device is a vehicle-mounted control module, and the second object device is a test case.

[0025] In a second aspect, the application provides a hardware-in-the-loop test board card, comprising:

[0026] The digital signal circuit for the hardware-in-the-loop test system as described in the first aspect is electrically connected with other functional modules in the test system through a board card connector to interact signals;

[0027] A power module is electrically connected with the digital signal circuit, and is used to provide working power for the digital signal circuit;

[0028] A signal interface module is arranged at an edge of the hardware-in-the-loop test board card, and is used to connect the first object device and the second object device.

[0029] In a third aspect, the application provides a test system, comprising a first object device, a second object device, and a hardware-in-the-loop test board card as described in the second aspect, one end of the hardware-in-the-loop test board card is connected with the first object device, and the other end is connected with the second object device, the first object device and the second object device interact signals through the hardware-in-the-loop test board card.

[0030] The digital signal circuit, the board, and the system for the hardware-in-the-loop test system of the application integrate the input signal processing module and the output signal processing module on the same printed circuit board, reduce the number of boards and the connection complexity required for the loop test, and set the input signal processing module and the output signal processing module on different layers of the printed circuit board respectively, so that the input signal and the output signal are transmitted through different layers of the printed circuit board respectively, without switching the signal transmission direction through the code switch, avoiding the error and inconvenience caused by manual operation, simplifying the operation process, and improving the test efficiency; the above-mentioned digital signal circuit further sets the electromagnetic shielding layer connected to the fixed potential between the input signal processing module and the output signal processing module, so as to shield the electromagnetic interference between the input signal processing module and the output signal processing module, reduce the interference between the input signal and the output signal, improve the accuracy and stability of signal transmission, effectively reduce the interference between signals, improve the accuracy and stability of signal transmission, and improve the test accuracy, so that the loop test is more efficient and reliable. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0032] Figure 1 A schematic diagram of a printed circuit board for a digital signal circuit of a hardware-in-the-loop (HIL) test system provided in an embodiment;

[0033] Figure 2 A schematic diagram of a first layer of a printed circuit board provided in an embodiment;

[0034] Figure 3 A schematic diagram of a second layer of a printed circuit board provided in an embodiment;

[0035] Figure 4 A schematic diagram of a third layer of a printed circuit board provided in an embodiment;

[0036] Figure 5 A block diagram of a third layer of a printed circuit board provided in an embodiment;

[0037] Figure 6 A block diagram of a fourth layer of a printed circuit board provided in an embodiment;

[0038] Figure 7 An equivalent circuit diagram of an input signal processing module provided in an embodiment;

[0039] Figure 8 Figure 8 is an equivalent circuit diagram of the output signal processing module provided in an embodiment. DETAILED DESCRIPTION

[0040] For the purpose of understanding the present application, a more complete description of the application will be provided with reference to the accompanying drawings. The drawings provided herein are for illustration purposes only and therefore are not intended to limit the scope of the application. The application can be implemented in numerous ways, including the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the application to those skilled in the art.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0042] It should be understood that the terms "first", "second" and so on as used herein can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the other element. For example, without departing from the scope of the application, the first resistor can be referred to as the second resistor, and similarly, the second resistor can be referred to as the first resistor. The first resistor and the second resistor are both resistors, but they are not the same resistor.

[0043] It should be understood that "connection" in the following embodiments means that the circuits, modules, units, etc. connected to each other have the transmission of electrical signals or data.

[0044] It should be understood that "at least one" means one or more, and "multiple" means two or more. "At least part of the element" means part or all of the element.

[0045] As used herein, the singular forms "a", "an" and "the" can include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "comprise / comprising" or "have / having" specifies the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but does not exclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in the specification includes any and all combinations of the related listed items.

[0046] In the related art, in the hardware-in-loop (HIL) test process, the input signals and output signals of the NI chassis and the vehicle-mounted ECU are processed by two independent board cards, and the input direction and output direction of the signals are changed by a DIP switch. However, this design may cause signal interference, affecting the accuracy of the test. Moreover, the signal direction is changed by manually switching the DIP switch, which is tedious and prone to errors, and the physical characteristics of the DIP switch also limit the speed and flexibility of signal switching.

[0047] According to an exemplary embodiment, the present application provides a digital signal circuit for a hardware-in-loop (HIL) test system, which is used to realize bidirectional signal conditioning and isolation between a first object device and a second object device. The digital signal circuit includes an input signal processing module and an output signal processing module; the input signal processing module is used to receive an initial input signal of the first object device and process the initial input signal into a target input signal and send the target input signal to the second object device, wherein the initial input signal is a digital signal input by the first object device to the second object device; the output signal processing module is used to receive an initial output signal of the second object device and process the initial output signal into a target output signal and send the target output signal to the first object device, wherein the initial output signal is a digital signal output by the second object device to the first object device; wherein, as shown in Figure 1 , in combination with the description of Figures 2-6 , the digital signal circuit is integrated on a printed circuit board 10, which includes a first layer 11, a second layer 12, a third layer 13 and a fourth layer 14 stacked in sequence; one of the input signal processing module and the output signal processing module is arranged on the first layer 11, and the other is arranged on the fourth layer 14; the second layer 12 is connected to a fixed potential, and is used to shield electromagnetic interference between the input signal processing module and the output signal processing module; the third layer 13 is a power supply layer, which is used to supply power to the input signal processing module and the output signal processing module respectively.

[0048] The digital signal circuit for the hardware-in-the-loop test system integrates the input signal processing module and the output signal processing module on the same printed circuit board 10, reduces the number of boards and the complexity of connection required for the loop test, and respectively sets the input signal processing module and the output signal processing module on different layers of the printed circuit board 10, so that the input signal and the output signal are transmitted through different layers of the printed circuit board 10 without the need to switch the signal transmission direction through the DIP switch, thereby avoiding errors and inconvenience caused by manual operation, simplifying the operation process, and improving the test efficiency; the digital signal circuit further sets the electromagnetic shielding layer connecting the fixed potential between the input signal processing module and the output signal processing module to shield the electromagnetic interference between the input signal processing module and the output signal processing module, thereby reducing the interference between the input signal and the output signal, improving the accuracy and stability of signal transmission, effectively reducing the interference between signals, improving the accuracy and stability of signal transmission, and improving the test accuracy, so that the loop test is more efficient and reliable.

[0049] In some embodiments, referring to Figure 3 , the second layer 12 is a whole metal layer, and the metal layer is grounded. For example, the second layer 12 can be a copper metal layer, and the thickness of the copper metal layer can be 15-20 μm. For example, the thickness of the copper metal layer can be 15 μm, 17 μm, 17.5 μm, 18 μm, 19 μm, or 20 μm.

[0050] In some embodiments, the area of the metal layer of the second layer 12 can be smaller than the area of the first layer 11 and the fourth layer 14. The second layer 12 can shield the signal interference between the first layer 11 and the fourth layer 14. For example, the area ratio of the second layer 12 to the first layer 11 can be 0.3:1-1:1. For example, the area ratio of the second layer 12 to the first layer 11 can be 0.3:1-, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, or 1:1.

[0051] In some embodiments, referring to Figure 4 , Figure 5 , the third layer 13 includes a first power supply module 131, a second power supply module 132, and an isolation module 133. The first power supply module 131 is connected with the input signal processing module and used to supply power to the input signal processing module. The second power supply module 132 is connected with the output signal processing module and used to supply power to the output signal processing module. The isolation module 133 is arranged between the first power supply module 131 and the second power supply module 132, and is used to isolate the electromagnetic interference between the first power supply module 131 and the second power supply module 132. For example, the isolation module 133 can be provided with a magnetic bead or an inductor.

[0052] The digital signal circuit of the embodiment, the first power supply module 131 and the second power supply module 132 of the power supply layer are independently arranged, and respectively supply power for the input signal processing module and the output signal processing module, so as to meet the different voltage requirements of the input signal processing module and the output signal processing module, and the isolation module 133 is arranged between the first power supply module 131 and the second power supply module 132, so as to reduce the noise coupling between the first power supply module 131 and the second power supply module 132, so as to ensure the stability and reliability of the voltage source.

[0053] In some embodiments, the wiring of the input signal processing module is arranged on the first layer 11 of the printed circuit board 10, the signal buffer circuit is connected with the first power supply module 131 of the power supply layer, the first power supply module 131 supplies power for the signal buffer circuit, and the power supply voltage of the first power supply module 131 is 4.5V-5.5V. The wiring of the output signal processing module is arranged on the fourth layer 14 of the printed circuit board 10, the signal driving circuit is connected with the second power supply module 132 of the power supply layer, the second power supply module 132 supplies power for the signal driving circuit, and the power supply voltage of the first power supply module 131 is 8V-12V.

[0054] In other embodiments, referring to Figure 2 , Figure 7 , the wiring of the output signal processing module is arranged on the fourth layer 14 of the printed circuit board 10, and the wiring of the input signal processing module is arranged on the fourth layer 14 of the printed circuit board 10.

[0055] In some embodiments, the metal layer of the second layer 12 is provided with a through hole, so that the power supply circuit of the third layer 13 power supply layer passes through the through hole of the second layer 12 and is connected with the input signal processing module or the output signal processing module of the first layer 11 to supply power. In this way, the circuit arrangement can be simplified, the wiring difficulty can be reduced, the voltage drop and electromagnetic interference (EMI) on the power supply circuit can be reduced, the power quality received by the signal processing module of the first layer 11 can be significantly improved, and the accuracy and stability of signal processing can be ensured.

[0056] In the embodiment, after the power supply circuit passes through the through hole of the second layer 12, the gap of the through hole around the power supply circuit is filled with resin material. The resin material has excellent insulation performance, can effectively isolate the power supply circuit from the surrounding metal layer, and prevent short circuit and electric leakage. The resin material tightly wraps the power supply circuit, and when the printed circuit board 10 is subjected to external stress such as vibration, impact or thermal expansion and contraction, the resin material can reduce the risk of fracture or deformation of the circuit due to stress concentration.

[0057] In some embodiments, referring to Figure 2 , Figure 7The input signal processing module includes a signal buffer circuit and an input protection circuit, an input end of the signal input circuit is connected to the first target device, and an output end of the signal input circuit is connected to the second target device; the input protection circuit is connected to an input end of the signal buffer circuit, and is configured to limit the voltage and current of the initial input signal; the input protection circuit includes a current-limiting resistor and a voltage stabilizing diode; the current-limiting resistor is arranged at the input end of the signal buffer circuit, the anode of the voltage stabilizing diode is grounded, and the cathode is connected to the input end of the signal buffer circuit. The current-limiting resistor is configured to limit the current of the initial input signal, thereby preventing the signal buffer circuit from being damaged by overcurrent. The voltage stabilizing diode is configured to clamp the voltage of the initial input signal within a safe range, thereby preventing the voltage peak of the initial input signal from damaging the signal buffer circuit. The current-limiting resistor R1 can limit the size of the current input to the signal buffer circuit, thereby playing a role of overcurrent protection for the signal buffer circuit. In addition, the voltage stabilizing diode can stabilize the voltage of the signal input to the input end of the signal buffer circuit, so that the level of the input signal remains stable. For example, the resistance value of the current-limiting resistor ranges from 3.3 kΩ to 6.8 kΩ. For example, the clamping voltage of the voltage stabilizing diode is 5.1 V±0.2 V.

[0058] The signal buffer circuit can be a buffer chip, and the specification of the buffer chip is SN74LVC1G34DBVR. The buffer chip is configured to enhance the driving capability of the input signal and ensure that the input signal can be stably transmitted to the second target device.

[0059] The signal buffer circuit receives the initial input signal from the first target device, buffers the initial input signal, shapes the waveform of the initial input signal, eliminates the distortion of the initial input signal, and then transmits the processed target input signal to the second target device. The buffer chip can adopt a rail-to-rail output architecture, and the buffer chip can ensure signal integrity within a power supply voltage range of 4.5 V to 5.5 V.

[0060] The digital signals of the first target device and the second target device interact with each other, and the voltage ranges of the digital signals corresponding to the first target device and the second target device are different. In order to realize the interaction of the digital signals between the first target device and the second target device, the digital signals need to be processed accordingly, so that the first target device and the second target device can both receive signals within their voltage acquisition ranges. In this embodiment, the input signal processing module converts the initial input signal output by the first target device into a target input signal that can be accepted by the second target device.

[0061] In the embodiment, the power supply pin of the buffer chip is connected with the first power supply module 131, and the power supply pin of the buffer chip is also grounded through the first filter capacitor C11. The first filter capacitor C11 is a 0.1 μF multilayer ceramic capacitor, which is used to suppress the high-frequency noise of the power supply circuit of the first power supply module 131.

[0062] In some embodiments, referring to Figure 6 、 Figure 8 , the output signal processing module includes a signal driving circuit and an output filter circuit. The input end of the signal driving circuit is connected with the first target device, and the output end of the signal input circuit is connected with the second target device. The output filter circuit is connected to the output end of the signal driving circuit, and is used to filter the high-frequency noise in the target output signal. The output filter circuit includes a second filter capacitor. The second filter capacitor C1 is a 0.1 μF multilayer ceramic capacitor.

[0063] The signal driving circuit can be a driving chip, and the specification of the driving chip is MCP1404T-E / SN. The signal driving circuit receives the initial output signal from the second target device, and performs driving processing on the initial output signal to enhance the driving capability of the initial input signal. The signal driving circuit converts the initial output signal output by the second target device into a target output signal that can be accepted by the first target device, and transmits the processed target output signal to the first target device.

[0064] In some embodiments, the input end of the signal driving circuit is also connected with a first voltage dividing resistor R1 and a second voltage dividing resistor R2. The first voltage dividing resistor R1 is connected in series between the output end of the second target device and the input end of the signal driving circuit. One end of the second voltage dividing resistor R2 is connected with the input end of the signal driving circuit, and the other end is grounded. The first voltage dividing resistor R1 and the second voltage dividing resistor R2 can achieve voltage division, and the effective voltage division ratio is R1 / (R1+R2). Since the high-level voltage of the initial output signal of the second target device is VCC, the high-level voltage input to the signal driving circuit is VCC*R1 / (R1+R2). The first voltage dividing resistor R1 and the second voltage dividing resistor R2 achieve the function of voltage division, so that the voltage input to the signal driving circuit is reduced. Therefore, this can also reduce the current in the circuit, thereby playing a role in overcurrent protection for the output signal processing module.

[0065] In some embodiments, the output end of the signal driving circuit is also provided with a pull-up resistor.

[0066] In some embodiments, referring to Figure 6 、 Figure 8The driving chip includes two input ends of a first input end INA and a second input end INB. The first input end INA is grounded through a second pull-down resistor R2. The second input end INB is connected to the power supply of the second power supply module 132 through a pull-up resistor R3 and grounded through a third pull-down resistor R4. The power supply pin of the driving chip is directly connected to the power supply of the second power supply module 132.

[0067] The driving chip includes two output ends of a first output end A and a second output end B. The first output end OUTA is connected to the switching power supply through a second filter capacitor C1. The second output end OUTB of the driving chip is suspended. The first output end OUTA is used for single-ended driving of the second object device.

[0068] In some embodiments, the first object device is an electronic control unit (ECU), and the second object device is a test box (NI).

[0069] In a second aspect, the present application provides a hardware-in-the-loop test board card, which includes the digital signal circuit, the power supply module and the signal interface module for the hardware-in-the-loop test system according to the first aspect. The digital signal circuit is electrically connected to other functional modules in the test system through a board card connector to interact signals. The power supply module is electrically connected to the digital signal circuit to provide working power for the digital signal circuit. The signal interface module is arranged at the edge of the hardware-in-the-loop test board card to connect the first object device and the second object device. In this embodiment, the signal interface module adopts a standardized interface to make the board card compatible with different types of devices. In this embodiment, the interface pins of the signal interface module are gold-plated to improve the reliability and anti-oxidation ability of signal transmission.

[0070] In this embodiment, the power supply module adopts a switching power supply design. The input voltage range is 9V-36V. The output voltage includes two paths of 5V±0.1V and 12V±0.2V, which respectively meet the different power supply requirements of the first power supply module 131 and the second power supply module 132 of the power supply layer of the printed circuit board 10 in the digital signal circuit. The output voltage stability of the power supply module is that the fluctuation of the 5V output voltage does not exceed ±0.05V, and the fluctuation of the 12V output voltage does not exceed ±0.1V under full load. The conversion efficiency of the power supply module is not less than 85% to reduce energy loss and heat generation.

[0071] In some embodiments, the hardware-in-the-loop test board card further includes a fixed mounting structure for fixedly mounting the hardware-in-the-loop test board card device in the slot of the HIL test box to ensure that the board card is firmly installed in the box and prevent loosening. For example, a guide groove is arranged on the fixed mounting structure, a guide strip is arranged in the slot of the HIL test box, and the guide groove of the fixed mounting structure cooperates with the guide strip of the test box slot to make the board card smooth during insertion and removal, thereby reducing the risk of damage to the board card or the slot caused by misoperation.

[0072] In some embodiments, the signal interface module is also provided with an electrostatic protection function, and a transient voltage suppression diode is connected in parallel at the interface pin, and the transient voltage suppression diode is used to quickly discharge static charge and protect the digital signal circuit from electrostatic discharge. For example, the breakdown voltage of the transient voltage suppression diode is 6V-8V, and the clamping voltage is 12V-15V.

[0073] The hardware-in-the-loop test board card described above integrates the input signal processing module and the output signal processing module on the same printed circuit board, reduces the number of board cards required for in-the-loop testing and the connection complexity, and sets the input signal processing module and the output signal processing module on different layers of the printed circuit board 10, respectively, so that the input signal and the output signal are transmitted through different layers of the printed circuit board 10, without the need to switch the signal transmission direction through the dip switch, avoiding errors and inconvenience caused by manual operation, simplifying the operation process, and improving the testing efficiency; the digital signal circuit described above further sets an electromagnetic shielding layer connected to a fixed potential between the input signal processing module and the output signal processing module, to shield electromagnetic interference between the input signal processing module and the output signal processing module, so as to reduce interference between the input signal and the output signal, improve the accuracy and stability of signal transmission, effectively reduce interference between signals, improve the accuracy and stability of signal transmission, and improve testing accuracy, so that in-the-loop testing is more efficient and reliable.

[0074] In a third aspect, the present application provides a test system, comprising a first object device, a second object device, and a hardware-in-the-loop test board card according to the second aspect, one end of the hardware-in-the-loop test board card is connected to the first object device, and the other end is connected to the second object device, and the first object device and the second object device interact signals through the hardware-in-the-loop test board card.

[0075] In the description of the present application, the description of the terms "some embodiments", "other embodiments", and the like means that the specific features, structures, materials, or characteristics described in connection with the embodiments or examples are contained in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example.

[0076] The technical features of the above-described embodiments can be combined in any manner. In order to make the description concise, not all possible combinations of the technical features of the above-described embodiments are described, but as long as the combinations of the technical features do not contradict, they should be considered as within the scope of the present application.

[0077] The above embodiments only express several implementation ways of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation to the patent scope of the application. It should be pointed out that for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, which all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A digital signal circuit for a hardware-in-the-loop test system, characterized in that: The digital signal circuit comprises: An input signal processing module, configured to receive an initial input signal from a first target device and process the initial input signal into a target input signal and send the target input signal to a second target device; an output signal processing module, configured to receive an initial output signal of the second target device and process the initial output signal into a target output signal and send the target output signal to the first target device; Wherein, the digital signal circuit is integrated on a printed circuit board, and the printed circuit board includes a first layer, a second layer, a third layer and a fourth layer stacked in sequence; One of the input signal processing module and the output signal processing module is arranged on the first layer, and the other is arranged on the fourth layer; the second layer is connected to a fixed potential, and the second layer is used to shield electromagnetic interference between the input signal processing module and the output signal processing module; the third layer is a power supply layer, and the power supply layer is used to supply power to the input signal processing module and the output signal processing module respectively.

2. The digital signal circuit for a hardware-in-the-loop test system according to claim 1, wherein: The second layer is a whole metal layer, and the metal layer is grounded.

3. The digital signal circuit for a hardware-in-the-loop test system according to claim 1, wherein: The third layer includes: a first power supply module, connected to the input signal processing module, and configured to supply power to the input signal processing module; a second power supply module, connected to the output signal processing module, and configured to supply power to the output signal processing module; The isolation module is provided between the first power supply module and the second power supply module, and is used to isolate electromagnetic interference between the first power supply module and the second power supply module.

4. The digital signal circuit for a hardware-in-the-loop test system according to claim 3, wherein: The isolation module includes a magnetic bead or an inductor.

5. The digital signal circuit for a hardware-in-the-loop test system according to any one of claims 1 to 4, characterized in that: The input signal processing module includes: a signal buffer circuit, wherein an input end of the signal input circuit is connected to the first target device, and an output end of the signal input circuit is connected to the second target device; An input protection circuit is connected to the input end of the signal buffer circuit, and is used to limit the voltage and current of the initial input signal; the input protection circuit includes a current limiting resistor and a voltage-stabilizing diode; the current limiting resistor is arranged at the input end of the signal buffer circuit, and the anode of the voltage-stabilizing diode is connected to a fixed potential, and the cathode is connected to the input end of the signal buffer circuit.

6. The digital signal circuit for a hardware-in-the-loop test system according to any one of claims 1 to 4, characterized in that: The output signal processing module includes: a signal driving circuit, wherein an input end of the signal driving circuit is connected to the first target device, and an output end of the signal input circuit is connected to the second target device; An output filter circuit is connected to the output end of the signal driving circuit, and is used to filter out high-frequency noise in the target output signal.

7. The digital signal circuit for a hardware-in-the-loop test system according to claim 6, wherein: The input end of the signal driving circuit is further connected to a first voltage dividing resistor and a second voltage dividing resistor.

8. The digital signal circuit for a hardware-in-the-loop test system according to claim 1, wherein: The first target device is a vehicle-mounted control module; the second target device is a test chassis.

9. A hardware-in-the-loop test board, characterized in that: include: The digital signal circuit for a hardware-in-the-loop test system according to any one of claims 1 to 8, wherein the digital signal circuit is electrically connected to other functional modules in the test system via a board connector to exchange signals; a power supply module, electrically connected to the digital signal circuit, and configured to provide working power to the digital signal circuit; The signal interface module is arranged at the edge of the hardware-in-the-loop test board and is used to connect the first target device and the second target device.

10. A testing system, characterized in that: The device comprises a first target device, a second target device, and a hardware-in-the-loop test board as claimed in claim 9, wherein one end of the hardware-in-the-loop test board is connected to the first target device, and the other end is connected to the second target device, and the first target device and the second target device exchange signals through the hardware-in-the-loop test board.

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