Relay double-side driving circuit and abnormal diagnosis method thereof

Abstract

The application discloses a relay double-side driving circuit and an abnormality diagnosis method thereof. The same type of control signals are sent to control ends of high and low side driving modules to control the high and low side driving modules to be closed or disconnected at the same time, so that a high side feedback signal of the high side driving module and a low side feedback signal of the low side driving module are obtained, and fault diagnosis of the relay is performed according to the type of the control signal, the high side feedback signal and the low side feedback signal. The application can avoid the problem that the relay is misoperated when the output end of the single-side driving circuit is short-circuited or open-circuited, and can accurately perform fault diagnosis of the relay, so that the safety and reliability of the vehicle are improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of driving circuit, in particular to a relay double-side driving circuit and an abnormal diagnosis method thereof. BACKGROUND

[0002] Electric vehicles usually use high-voltage power batteries to provide power. In order to meet the needs of the whole vehicle, the battery system needs to provide different power supply circuits, for example, the discharge circuit needs to be connected when the vehicle is running, the charging circuit needs to be connected when the battery is charging, and the heating circuit needs to be connected when the battery is heating. In order to ensure the control of these different circuits, the on-off of the high-voltage relay in the circuit needs to be controlled according to the requirements.

[0003] The controller of the relay in the past generally uses chip low-side driving, which is driven and diagnosed by the chip. However, this scheme still has some shortcomings: single-side driving is not conducive to safety and is prone to cause misoperation of the relay; if the driving wire breaks down, the relay will not be able to run. If the wire harness has a short ground fault, it will cause the vehicle to be unable to lower the high voltage, which poses a risk of electric shock. If the wire harness of the high-voltage relay is misdiagnosed, it will cause abnormal high voltage or inability to raise the high voltage, which will cause poor robustness of the vehicle.

[0004] Therefore, it is necessary to design a safe, reliable and misdiagnosis-avoiding relay control circuit and diagnosis scheme. SUMMARY

[0005] The purpose of the application is to provide a relay double-side driving circuit and an abnormal diagnosis method thereof. The application designs a relay double-side driving circuit and an abnormal diagnosis method thereof, which solves the problems of single-side driving being not conducive to safety and being prone to cause misoperation and misdiagnosis of the relay.

[0006] To solve the above technical problems, the application provides a relay double-side driving circuit, which comprises:

[0007] a processing module;

[0008] a high-side driving module, an input end of which is connected with a driving power supply, an output end of which is connected with a first end of a relay, and a control end of which is connected with the processing module, the high-side driving module being used for controlling the communication state between the driving power supply and the first end of the relay according to the control signal of the processing module;

[0009] a low-side driving module, an input end of which is connected with a second end of the relay, an output end of which is grounded, and a control end of which is connected with the processing module, the low-side driving module being used for controlling the communication state between the second end of the relay and the ground according to the control signal of the processing module;

[0010] The processing module is configured to send the same type of control signal to the control end of the high-side drive module and the low-side drive module, so as to control the high-side drive module and the low-side drive module to be closed or disconnected at the same time, to obtain a high-side feedback signal of the high-side drive module and a low-side feedback signal of the low-side drive module, and to perform fault diagnosis on the relay according to the type of the control signal, the high-side feedback signal and the low-side feedback signal.

[0011] The high-side feedback signal is a first voltage sampling value of a high-side drive signal at the output end of the high-side drive module, and the low-side feedback signal is a second voltage sampling value of a low-side drive signal at the input end of the low-side drive module, or a fault diagnosis type fed back by the low-side drive module.

[0012] In an embodiment of the present application, the high-side drive module comprises a high-side drive unit and a first pull-up sampling unit.

[0013] The high-side drive unit is configured to output a high-side drive signal to the first end of the relay according to the control signal of the processing module.

[0014] The first pull-up sampling unit is configured to sample the high-side drive signal at the output end of the high-side drive unit to obtain the first voltage sampling value.

[0015] In an embodiment of the present application, the first pull-up sampling unit comprises a first feedback resistor, a first pull-up resistor and a first pull-down resistor.

[0016] One end of the first pull-up resistor is connected with a pull-up power supply, and the other end is connected with the output end of the high-side drive module.

[0017] One end of the first pull-down resistor is connected with the output end of the high-side drive module, and the other end is grounded.

[0018] One end of the first feedback resistor is connected with the output end of the high-side drive module, and the other end is connected with the processing module.

[0019] In an embodiment of the present application, the low-side drive module comprises a low-side drive unit and a second pull-up sampling unit.

[0020] The low-side drive unit is configured to output a low-side drive signal to the second end of the relay according to the low-side control signal of the processing module.

[0021] The second pull-up sampling unit is configured to sample the low-side drive signal at the input end of the low-side drive unit to obtain the second voltage sampling value.

[0022] In one embodiment of the present application, the second pull-up sampling unit comprises a second feedback resistor, a second pull-up resistor and a second pull-down resistor.

[0023] One end of the second pull-up resistor is connected with a pull-up power supply, and the other end is connected with an input end of the low-side drive module.

[0024] One end of the second pull-down resistor is connected with the input end of the low-side drive module, and the other end is grounded.

[0025] One end of the second feedback resistor is connected with the input end of the low-side drive module, and the other end is connected with the processing module.

[0026] In one embodiment of the present application, when the high-side feedback signal is the first voltage sampling value and the low-side feedback signal is the second voltage sampling value;

[0027] According to the type of the control signal, the high-side feedback signal and the low-side feedback signal, the fault diagnosis of the relay is performed, comprising:

[0028] The first voltage sampling value and the second voltage sampling value are compared with corresponding voltage threshold values respectively to generate voltage comparison results.

[0029] According to the type of the control signal and the voltage comparison results, the fault diagnosis of the relay is performed.

[0030] In one embodiment of the present application, comparing the first voltage sampling value and the second voltage sampling value with corresponding voltage threshold values respectively to generate voltage comparison results comprises:

[0031] The first voltage sampling value is compared with a first voltage threshold value, a second voltage threshold value and a third voltage threshold value respectively to determine a voltage interval in which the first voltage sampling value is located.

[0032] The second voltage sampling value is compared with the first voltage threshold value, the second voltage threshold value and the third voltage threshold value respectively to determine a voltage interval in which the second voltage sampling value is located.

[0033] The voltage interval in which the first voltage sampling value is located and the voltage interval in which the second voltage sampling value is located are taken as voltage comparison results.

[0034] The first voltage threshold value is smaller than the second voltage threshold value, and the second voltage threshold value is smaller than the third voltage threshold value.

[0035] In one embodiment of the present application, when the control signals sent by the processing module to the control ends of the high-side drive module and the low-side drive module are both disable signals, the fault diagnosis of the relay is performed according to the type of the control signal and the voltage comparison result, including:

[0036] When the first voltage sampling value is greater than the first voltage threshold value and less than or equal to the second voltage threshold value, and the second voltage sampling value is greater than the first voltage threshold value and less than or equal to the third voltage threshold value, the relay is in a normal state.

[0037] When the first voltage sampling value and the second voltage sampling value are both greater than the third voltage threshold value, the relay is in a high-side power supply short circuit fault and / or a low-side power supply short circuit fault.

[0038] When the first voltage sampling value and the second voltage sampling value are both less than or equal to the first voltage threshold value, the relay is in a high-side ground short circuit fault and / or a low-side ground short circuit fault.

[0039] When the first voltage sampling value is greater than the second voltage threshold value and less than or equal to the third voltage threshold value, the relay is in an open circuit fault.

[0040] In one embodiment of the present application, when the control signals sent by the processing module to the control ends of the high-side drive module and the low-side drive module are both enable signals, the fault diagnosis of the relay is performed according to the type of the control signal and the voltage comparison result, including:

[0041] When the first voltage sampling value is greater than the third voltage threshold value, and the second voltage sampling value is less than the first voltage threshold value, the relay is in a normal state.

[0042] When the first voltage sampling value and the second voltage sampling value are both less than or equal to the first voltage threshold value, the relay is in a high-side ground short circuit fault.

[0043] When the first voltage sampling value and the second voltage sampling value are both greater than the third voltage threshold value, the relay is in a low-side power supply short circuit fault.

[0044] In one embodiment of the present application, the low-side drive module includes an SBC drive chip, which is used to output a low-side drive signal to the second end of the relay according to the control signal of the processing module, perform fault diagnosis at the same time, and feed back the fault diagnosis result to the processing module.

[0045] In one embodiment of the present application, the fault diagnosis of the relay is performed according to the type of the control signal, the high-side feedback signal and the low-side feedback signal, including:

[0046] comparing the first voltage sampling value with a corresponding voltage threshold value to generate a voltage comparison result;

[0047] performing fault diagnosis of the relay according to the type of the control signal, the voltage comparison result and a fault diagnosis result fed back by the low-side drive module.

[0048] In an embodiment of the present application, comparing the first voltage sampling value with a corresponding voltage threshold value to generate a voltage comparison result comprises,

[0049] comparing the first voltage sampling value with a fourth voltage threshold value and a fifth voltage threshold value respectively to determine a voltage interval in which the first voltage sampling value is located;

[0050] The fourth voltage threshold value is less than the fifth voltage threshold value.

[0051] In an embodiment of the present application, when the control signals sent by the processing module to the control terminals of the high-side drive module and the low-side drive module are both disable signals, performing fault diagnosis of the relay according to the type of the control signal, the voltage comparison result and a fault diagnosis result fed back by the low-side drive module comprises,

[0052] when the first voltage sampling value is greater than the fourth voltage threshold value and less than or equal to the fifth voltage threshold value, and the fault diagnosis result fed back by the low-side drive module is a normal state, the relay is in a normal state;

[0053] when the first voltage sampling value is greater than the fourth voltage threshold value and less than or equal to the fifth voltage threshold value, and the fault diagnosis result fed back by the low-side drive module is an open circuit fault, the relay is in an open circuit fault;

[0054] when the first voltage sampling value is greater than the fifth voltage threshold value, and the fault diagnosis result fed back by the low-side drive module is a normal state, the relay is in a high-side power supply short circuit fault and / or a low-side power supply short circuit fault;

[0055] when the first voltage sampling value is less than or equal to the fourth voltage threshold value, and the fault diagnosis result fed back by the low-side drive module is a ground short circuit fault, the relay is in a high-side ground short circuit fault and / or a low-side ground short circuit fault.

[0056] In an embodiment of the present application, when the control signals sent by the processing module to the control terminals of the high-side drive module and the low-side drive module are both enable signals, performing fault diagnosis of the relay according to the type of the control signal, the voltage comparison result and a fault diagnosis result fed back by the low-side drive module comprises,

[0057] When the first voltage sampling value is greater than the fifth voltage threshold value, and the failure diagnosis result fed back by the low-side drive module is a normal state, the relay is in a normal state.

[0058] When the first voltage sampling value is less than or equal to the fourth voltage threshold value, and the failure diagnosis result fed back by the low-side drive module is a normal state, the relay is in a high-side ground short circuit failure.

[0059] When the first voltage sampling value is greater than the fifth voltage threshold value, and the failure diagnosis result fed back by the low-side drive module is a power supply short circuit failure, the relay is in a low-side power supply short circuit failure.

[0060] In an embodiment of the present application, when the control signals sent by the processing module to the control ends of the high-side drive module and the low-side drive module are both disable signals, and the failure diagnosis result fed back by the low-side drive module is an open circuit failure, the processing module is further configured to

[0061] send an enable signal to the low-side drive module and send a disable signal to the high-side drive module;

[0062] acquire a third voltage sampling value of a high-side drive signal at an output end of the high-side drive module;

[0063] When the third voltage sampling value is less than or equal to the fifth voltage threshold value, the relay is in a normal state.

[0064] When the third voltage sampling value is greater than the fourth voltage threshold value and less than or equal to the fifth voltage threshold value, the relay is in an open circuit failure.

[0065] To achieve the purposes and other related purposes of the present application, the present application further provides an abnormal diagnosis method of the relay double-side drive circuit according to any one of the above, comprising:

[0066] sending the same type of control signals to the control ends of the high-side drive module and the low-side drive module to control the high-side drive module and the low-side drive module to be closed simultaneously or to be opened simultaneously;

[0067] acquiring a high-side feedback signal of the high-side drive module and a low-side feedback signal of the low-side drive module;

[0068] performing failure diagnosis of the relay according to the type of the control signal, the high-side feedback signal and the low-side feedback signal;

[0069] The high-side feedback signal is a first voltage sampling value of a high-side drive signal at an output end of the high-side drive module, the low-side feedback signal is a second voltage sampling value of a low-side drive signal at an input end of the low-side drive module, or a fault diagnosis type fed back by the low-side drive module.

[0070] The relay double-side drive circuit comprises a processing module, a high-side drive module, a low-side drive module, and a driving power source. The processing module is configured to send a same type of control signal to control ends of the high-side drive module and the low-side drive module, so as to control the high-side drive module and the low-side drive module to be closed or opened at the same time, to obtain a high-side feedback signal of the high-side drive module and a low-side feedback signal of the low-side drive module, and to perform fault diagnosis of the relay according to a type of the control signal, the high-side feedback signal, and the low-side feedback signal. The high-side feedback signal is a first voltage sampling value of a high-side drive signal at an output end of the high-side drive module, the low-side feedback signal is a second voltage sampling value of a low-side drive signal at an input end of the low-side drive module, or a fault diagnosis type fed back by the low-side drive module.

[0071] The application rechecks the open circuit fault diagnosed by the SBC drive chip when the relay is not driven, thereby avoiding the abnormal driving caused by the false report of the open circuit fault of the SBC drive chip, and further avoiding the abnormal high voltage or the failure to raise the high voltage, and improving the robustness of the vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0072] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed for the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0073] Figure 1A module schematic diagram of a relay double-side driving circuit provided by an example embodiment of the present application.

[0074] Figure 2 A circuit structure schematic diagram of a relay double-side driving circuit provided by an example embodiment of the present application.

[0075] Figure 3 A circuit structure schematic diagram of a relay double-side driving circuit provided by another example embodiment of the present application. DETAILED DESCRIPTION

[0076] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0077] To solve the problems that single-side driving is not conducive to safety, the relay cannot run when the driving line has a breakage fault, and the vehicle cannot go down high voltage and there is a risk of electric shock when the wire harness has a short-to-ground fault, the present application provides a double-side driving circuit, which will be described in detail below.

[0078] It should be understood that the present application only takes a relay as an example to be described in detail as a double-side driving device, and the double-side driving circuit and the diagnosis method thereof can also be applied to other double-side driving devices.

[0079] Please refer to Figures 1-3 In an example embodiment of the present application, the relay double-side driving circuit includes a processing module 1, a low-side driving module 2, and a high-side driving module 3, wherein the relay can be a main positive relay, a main negative relay, a pre-charging relay, a charging positive high-voltage relay, a charging negative high-voltage relay, etc.

[0080] The input end (connected to a 12V port) of the high-side driving module 3 is connected to a driving power supply, the output end is connected to the first end of the relay 4, and the control end is connected to the processing module 1. The high-side driving module 3 is used to control the communication state between the driving power supply and the first end of the relay 1 according to the high-side control signal of the processing module 1, wherein the driving power supply is a 12V direct current power supply, and of course can also be a 24V direct current power supply, a 48V direct current power supply, or other suitable direct current power supplies.

[0081] The low-side drive module 2 is connected with the second end of the relay 4 at the input end and grounded at the output end, and is connected with the processing module 1 at the control end, and is configured to control the communication state between the second end of the relay and the ground according to the low-side control signal of the processing module 1.

[0082] The processing module 1 is configured to send the same type of control signal to the control end of the high-side drive module 3 and the low-side drive module 2, so as to control the high-side drive module 3 and the low-side drive module 2 to be closed or opened at the same time, to obtain the high-side feedback signal of the high-side drive module 3 and the low-side feedback signal of the low-side drive module 2, and to perform the fault diagnosis of the relay 4 according to the type of the control signal, the high-side feedback signal and the low-side feedback signal.

[0083] The high-side feedback signal is the first voltage sampling value of the high-side drive signal at the output end of the high-side drive module 3, and the low-side feedback signal is the second voltage sampling value of the low-side drive signal at the input end of the low-side drive module 2, or the fault diagnosis type of the low-side drive module.

[0084] Please refer to Figure 2 In an embodiment, the high-side drive module 3 includes a high-side drive unit HSD and a first pull-up sampling unit. The high-side drive unit HSD is connected with the processing module 1, and is configured to output a high-side drive signal to the first end of the relay 4 according to the high-side control signal of the processing module 1, so as to control the communication state between the driving power supply and the first end of the relay 4. The first pull-up sampling unit is connected with the output end of the high-side drive unit HSD and the processing module 1, and is configured to sample the high-side drive signal at the output end of the high-side drive module 3, to obtain the first voltage sampling value as the high-side feedback signal, and send the high-side feedback signal to the processing module 1.

[0085] Please refer to Figure 2 In an embodiment, the first sampling unit includes a feedback resistor R1 (as a first feedback resistor), a pull-up resistor R2 (as a first pull-up resistor) and a pull-down resistor R3 (as a first pull-down resistor). One end of the pull-up resistor R2 is connected with a pull-up power supply, and the other end of the pull-up resistor R2 is connected with the output end of the high-side drive module 3. In the exemplary embodiment of the present application, the voltage of the pull-up power supply is 5V. One end of the pull-down resistor R3 is connected with the output end of the high-side drive module 3, and the other end of the pull-down resistor R3 is grounded. One end of the feedback resistor R1 is connected with the output end of the high-side drive module 3, and the other end of the feedback resistor R1 is connected with the processing module 1.

[0086] Please refer toFigure 2 As shown in the figure, in an embodiment, the low-side driving module 2 comprises a low-side driving unit LSD (Low-Side Driver) connected with the processing module 1, and an output end of the low-side driving unit LSD is connected with the high-side driving module 3 to control the communication state between the second end of the relay 4 and the ground. A second pull-up sampling unit is connected with the input end of the low-side driving unit LSD and the processing module 1, and is used to sample the low-side driving signal at the input end of the low-side driving unit LSD to obtain the second voltage sampling value as a low-side feedback signal and send it to the processing module.

[0087] Please refer to Figure 2 As shown in the figure, in an embodiment, the second sampling unit comprises a feedback resistor R4 (as a second feedback resistor), a pull-up resistor R5 (as a second pull-up resistor) and a pull-down resistor R6 (as a second pull-down resistor). One end of the pull-up resistor R5 is connected with a pull-up power supply, and the other end of the pull-up resistor R5 is connected with the input end of the low-side driving module 2. In the exemplary embodiment of the present application, the voltage of the pull-up power supply is 5V. One end of the pull-down resistor R6 is connected with the input end of the low-side driving module 2, and the other end of the pull-down resistor R6 is grounded. One end of the feedback resistor R4 is connected with the input end of the low-side driving module 2, and the other end of the feedback resistor R4 is connected with the processing module 1.

[0088] It should be understood that, in the exemplary embodiment of the present application, the circuit structures adopted by the first sampling unit and the second sampling unit are the same. Of course, in other embodiments, the circuit structures of the first sampling unit and the second sampling unit can also be different, or other sampling circuits can be adopted for sampling, and the various voltage thresholds described below can be adjusted adaptively.

[0089] Please refer to Figure 2 As shown in the figure, in an embodiment, the processing module 1 is used to receive the high-side feedback signal V H and the low-side feedback signal V L , and perform fault diagnosis of the relay 4 according to the type of the control signal, the high-side feedback signal V H and the low-side feedback signal V L .

[0090] Please refer to Figure 2As shown, in an embodiment, the high-side feedback signal is the first voltage sampling value, and the low-side feedback signal is the second voltage sampling value. When the fault diagnosis of the relay 4 is performed according to the type of the control signal, the high-side feedback signal, and the low-side feedback signal, the first voltage sampling value and the second voltage sampling value can be compared with corresponding voltage thresholds respectively to generate voltage comparison results. The fault diagnosis of the relay 4 is performed according to the type of the control signal and the voltage comparison results.

[0091] Specifically, when the first voltage sampling value and the second voltage sampling value are compared with corresponding voltage thresholds respectively to generate voltage comparison results, the first voltage sampling value can be compared with a first voltage threshold, a second voltage threshold, and a third voltage threshold respectively to determine the voltage interval in which the first voltage sampling value is located. Meanwhile, the second voltage sampling value can be compared with the first voltage threshold, the second voltage threshold, and the third voltage threshold respectively to determine the voltage interval in which the second voltage sampling value is located. The voltage interval in which the first voltage sampling value is located and the voltage interval in which the second voltage sampling value is located are taken as voltage comparison results. The first voltage threshold is less than the second voltage threshold, and the second voltage threshold is less than the third voltage threshold. It should be noted that the first voltage threshold, the second voltage threshold, and the third voltage threshold are related to the voltage of the pull-up power supply, the voltage of the driving power supply, the resistance of the relay 4, and the pull-up resistance, the pull-down resistance, and the feedback resistance of the corresponding pull-up sampling unit.

[0092] It should be noted that, in order to further clarify the meaning of each fault type, each fault type is further explained. The short circuit to ground (SCG) means that the current directly flows from a certain point in the circuit to the ground, bypassing the original circuit path. The short circuit to battery (SCB) means that a certain point in the circuit is incorrectly connected to the power supply. The open loop (OL) fault means that a certain part of the circuit cannot flow due to disconnection or failure.

[0093] When the control signals sent by the processing module 1 to the control ends of the high-side driving module 3 and the low-side driving module 2 are both disable signals, i.e., the relay is disconnected, when the fault diagnosis of the relay 4 is performed according to the type of the control signal and the voltage comparison results, the following cases can be included:

[0094] When the first voltage sampling value is greater than the first voltage threshold and less than or equal to the second voltage threshold, and the second voltage sampling value is greater than the first voltage threshold and less than or equal to the third voltage threshold, the relay 4 is in a normal state.

[0095] When the first voltage sampling value and the second voltage sampling value are both greater than the third voltage threshold, the relay 4 is a high-side short-circuit-to-battery (HSD SCB) fault and / or a low-side short-circuit-to-battery (LSD SCB) fault;

[0096] When the first voltage sampling value and the second voltage sampling value are both less than or equal to the first voltage threshold, the relay 4 is a high-side short-circuit-to-ground (HSD SCG) fault and / or a low-side short-circuit-to-ground (LSD SCG) fault;

[0097] When the first voltage sampling value is greater than the second voltage threshold and less than or equal to the third voltage threshold, the relay 4 is an open-circuit (OL) fault.

[0098] When the control signals sent by the processing module to the control ends of the high-side drive module and the low-side drive module are both enable signals, i.e., the relay is closed, the fault diagnosis of the relay 4 according to the type of the control signal and the voltage comparison result can include the following cases:

[0099] When the first voltage sampling value is greater than the third voltage threshold and the second voltage sampling value is less than the first voltage threshold, the relay 4 is in a normal state;

[0100] When the first voltage sampling value and the second voltage sampling value are both less than or equal to the first voltage threshold, the relay 4 is a high-side short-circuit-to-ground (HSD SCG) fault;

[0101] When the first voltage sampling value and the second voltage sampling value are both greater than the third voltage threshold, the relay 4 is a low-side short-circuit-to-battery (LSD SCB) fault;

[0102] In other cases that do not belong to the above three cases, it indicates that an abnormal situation that is not expected occurs in the circuit, and it is determined as an error or other fault.

[0103] Referring to Table 1, in the exemplary embodiments of the present application, the first voltage threshold, the second voltage threshold, and the third voltage threshold are obtained according to actual circuit experiments and calculation analysis, and are 1V, 3.5V, and 4.6V, respectively. H represents the first voltage sampling value, V L represents the second voltage sampling value. Of course, in other embodiments, the first voltage threshold, the second voltage threshold, and the third voltage threshold can be other values set according to the circuit.

[0104] Table 1

[0105]

[0106] Please refer to Figure 3 In another embodiment of the present application, the double-side driving circuit is different from the above exemplary embodiment in that the low-side driving module 2 is an SBC (System Basis Chip) driving chip, which is connected with the processing module 1 and communicates with the processing module 1 bidirectionally, and is used to output a low-side driving signal to the second end of the relay 4 according to a low-side control signal output by the processing module 1, so as to control the communication state between the second end of the relay 4 and the ground. The SBC driving chip can also perform fault diagnosis and send the fault diagnosis result to the processing module 1. It should be noted that the fault diagnosis result of the SBC driving chip is not completely accurate, and can be used as a low-side feedback signal together with the first voltage sampling value as a high-side feedback signal as a basis for fault diagnosis of the relay.

[0107] When the processing module 1 performs fault diagnosis of the relay 4 according to the type of the control signal, the high-side feedback signal and the low-side feedback signal, the first voltage sampling value can be compared with the corresponding voltage threshold value to generate a voltage comparison result; and then the fault diagnosis of the relay 4 is performed according to the type of the control signal, the voltage comparison result and the fault diagnosis result fed back by the low-side driving module 2.

[0108] Specifically, comparing the first voltage sampling value with the corresponding voltage threshold value to generate a voltage comparison result means comparing the first voltage sampling value with a fourth voltage threshold value and a fifth voltage threshold value respectively to determine the voltage interval in which the first voltage sampling value is located; wherein the fourth voltage threshold value is less than the fifth voltage threshold value. It should be noted that the fourth voltage threshold value, the fifth voltage threshold value and the voltage of the pull-up power supply, the voltage of the driving power supply, the resistance of the relay 4 and the pull-up resistance, the pull-down resistance, the feedback resistance of the corresponding pull-up sampling unit and other circuit parameters are related.

[0109] When the control signals sent by the processing module to the control ends of the high-side driving module 3 and the low-side driving module 2 are both disable signals, i.e. the relay 5 is disconnected, the fault diagnosis of the relay 4 according to the type of the control signal, the voltage comparison result and the fault diagnosis result fed back by the low-side driving module 2 can include the following cases:

[0110] When the first voltage sampling value is greater than the fourth voltage threshold value and less than or equal to the fifth voltage threshold value, and the fault diagnosis result fed back by the low-side driving module 2 is a normal state, then the relay 4 is in a normal state;

[0111] When the first voltage sampling value is greater than the fourth voltage threshold value and less than or equal to the fifth voltage threshold value, and the fault diagnosis result of the low-side drive module 2 is open circuit (OL) fault, then the relay 4 is open circuit (OL) fault.

[0112] When the first voltage sampling value is greater than the fifth voltage threshold value, and the fault diagnosis result of the low-side drive module 2 is normal state, then the relay 4 is high-side short circuit to power supply (HSD SCB) fault and / or low-side short circuit to power supply (LSD SCB) fault.

[0113] When the first voltage sampling value is less than or equal to the fourth voltage threshold value, and the fault diagnosis result of the low-side drive module 2 is short circuit to ground (SCG) fault, then the relay is high-side short circuit to ground (HSD SCG) fault and / or low-side short circuit to ground (LSD SCG) fault.

[0114] When the control signals sent by the processing module to the control terminals of the high-side drive module 3 and the low-side drive module 2 are both enable signals, i.e. the relay 4 is closed, the fault diagnosis of the relay 4 is performed according to the type of the control signal, the voltage comparison result and the fault diagnosis result of the low-side drive module 2, which can include the following cases:

[0115] When the first voltage sampling value is greater than the fifth voltage threshold value, and the fault diagnosis result of the low-side drive module 2 is normal state, then the relay 4 is normal state.

[0116] When the first voltage sampling value is less than or equal to the fourth voltage threshold value, and the fault diagnosis result of the low-side drive module 2 is normal state, then the relay 4 is high-side short circuit to ground (HSD SCG) fault.

[0117] When the first voltage sampling value is greater than the fifth voltage threshold value, and the fault diagnosis result of the low-side drive module 2 is short circuit to power supply (SCB) fault, then the relay is low-side short circuit to power supply (LSD SCG) fault.

[0118] If it is not the above-mentioned three cases, it means that the circuit has an abnormal situation that is not expected, and is determined as an error or other fault.

[0119] Please refer to Table 2, in another exemplary embodiment of the present application, the fourth voltage threshold value and the fifth voltage threshold value are obtained according to actual circuit experiments and calculation analysis of the present application, which are 1.2V and 4.6V respectively, V H represents the first voltage sampling value, V L represents the second voltage sampling value.

[0120] Table 2

[0121]

[0122] As shown in Table 3, the application also provides a false open circuit fault verification scheme for the low-side drive module 2 using the SBC drive chip. Specifically, when the control signals sent by the processing module 1 to the control terminals of the high-side drive module 3 and the low-side drive module 2 are both disable signals, that is, the relay 4 is disconnected, and the fault diagnosis result fed back by the low-side drive module 2 is an open circuit (OL) fault, the processing module 1 can also send an enable signal to the low-side drive module 2 and send a disable signal to the high-side drive module 3; obtain a third voltage sampling value V H of the high-side drive signal at the output terminal of the high-side drive module 3. H When the third voltage sampling value V is less than or equal to the fifth voltage threshold, the relay 5 is in a normal state; when the third voltage sampling value is greater than the fourth voltage threshold and less than or equal to the fifth voltage threshold, the relay is in an open circuit OL fault.

[0123] Table 3

[0124]

[0125] By setting the above false open circuit fault verification scheme, secondary verification can be performed when the SBC drive chip diagnosis result is an open circuit fault, thereby avoiding SBC drive chip false open circuit fault and driving abnormality, and further causing abnormal high voltage or unable to raise high voltage, thereby improving the robustness of the vehicle.

[0126] In summary, by using the application, the problem of relay misoperation caused by short circuit or open circuit fault at the output terminal of the single-sided drive circuit can be avoided, and accurate relay fault diagnosis can be performed on the relay double-sided drive circuit, thereby improving the safety and reliability of the vehicle.

[0127] For the application, when the SBC drive chip is used as the low-side drive module, the open circuit fault diagnosed by the SBC drive chip is re-verified when the relay is not driven, thereby avoiding SBC drive chip false open circuit fault and driving abnormality, and further causing abnormal high voltage or unable to raise high voltage, thereby improving the robustness of the vehicle.

[0128] For the application, when the SBC drive chip is used as the low-side drive module, the open circuit fault diagnosed by the SBC drive chip is re-verified when the relay is not driven, thereby avoiding SBC drive chip false open circuit fault and driving abnormality, and further causing abnormal high voltage or unable to raise high voltage, thereby improving the robustness of the vehicle.

[0129] The above description is only the preferred embodiment of the present application and the explanation of the technical principles applied, and those skilled in the art should understand that the scope of the present application is not limited to the technical solutions formed by the specific combinations of the above technical features, and should also cover other technical solutions formed by the combinations of the above technical features or their equivalent features without departing from the inventive concept, for example, the technical solutions formed by the mutual replacement of the above features and the technical features disclosed in the present application (but not limited to) having similar functions.

[0130] In addition to the technical features described in the specification, the remaining technical features are known to those skilled in the art, and in order to highlight the innovative features of the present application, the remaining technical features will not be described here.

Claims

1. A relay bilateral drive circuit, characterized in that, include: Processing module; A high-side drive module has an input terminal connected to a drive power supply, an output terminal connected to the first terminal of a relay, and a control terminal connected to the processing module. The high-side drive module is used to control the connection state between the drive power supply and the first terminal of the relay according to the control signal of the processing module. The low-side drive module has its input terminal connected to the second terminal of the relay, its output terminal grounded, and its control terminal connected to the processing module. The low-side drive module is used to control the connection state between the second terminal of the relay and ground according to the control signal of the processing module. The processing module is used to send the same type of control signal to the control terminals of the high-side drive module and the low-side drive module to control the high-side drive module and the low-side drive module to close or open at the same time, so as to obtain the high-side feedback signal of the high-side drive module and the low-side feedback signal of the low-side drive module, and perform relay fault diagnosis according to the type of control signal, the high-side feedback signal and the low-side feedback signal. Wherein, the high-side feedback signal is the first voltage sample value of the high-side drive signal at the output terminal of the high-side drive module, and the low-side feedback signal is the fault diagnosis type fed back by the low-side drive module; The low-side drive module includes an SBC drive chip, which is used to output a low-side drive signal to the second terminal of the relay according to the control signal of the processing module, and at the same time perform fault diagnosis and feed back the fault diagnosis result to the processing module.

2. The relay dual-sided drive circuit according to claim 1, characterized in that, The low-side drive module includes an SBC drive chip, which is used to output a low-side drive signal to the second terminal of the relay according to the control signal of the processing module, and at the same time perform fault diagnosis and feed back the fault diagnosis result to the processing module.

3. The relay dual-sided drive circuit according to claim 1, characterized in that, Fault diagnosis of the relay is performed based on the type of control signal, the high-side feedback signal, and the low-side feedback signal, including: The first voltage sample value is compared with the corresponding voltage threshold to generate a voltage comparison result; The relay is diagnosed based on the type of control signal, the voltage comparison result, and the fault diagnosis result fed back by the low-side drive module.

4. The relay dual-sided drive circuit according to claim 1, characterized in that, The first voltage sample value is compared with the corresponding voltage threshold to generate a voltage comparison result, including: The first voltage sample value is compared with the fourth voltage threshold and the fifth voltage threshold respectively to determine the voltage range in which the first voltage sample value is located; The fourth voltage threshold is less than the fifth voltage threshold.

5. The relay dual-sided drive circuit according to claim 4, characterized in that, When the control signals sent by the processing module to the control terminals of both the high-side drive module and the low-side drive module are disabled signals, fault diagnosis of the relay is performed based on the type of control signal, the voltage comparison result, and the fault diagnosis result fed back by the low-side drive module, including: When the first voltage sample value is greater than the fourth voltage threshold but less than or equal to the fifth voltage threshold, and the fault diagnosis result fed back by the low-side drive module is normal, then the relay is in normal condition. When the first voltage sample value is greater than the fourth voltage threshold but less than or equal to the fifth voltage threshold, and the fault diagnosis result fed back by the low-side drive module is an open circuit fault, then the relay is an open circuit fault. When the first voltage sample value is greater than the fifth voltage threshold, and the fault diagnosis result fed back by the low-side drive module is normal, then the relay is a high-side power supply short circuit fault and / or a low-side power supply short circuit fault. When the first voltage sample value is less than or equal to the fourth voltage threshold, and the fault diagnosis result fed back by the low-side drive module is a ground short circuit fault, then the relay is a high-side ground short circuit fault and / or a low-side ground short circuit fault.

6. The relay dual-sided drive circuit according to claim 4, characterized in that, When the control signals sent by the processing module to the control terminals of both the high-side drive module and the low-side drive module are enable signals, fault diagnosis of the relay is performed based on the type of control signal, the voltage comparison result, and the fault diagnosis result fed back by the low-side drive module, including: When the first voltage sample value is greater than the fifth voltage threshold, and the fault diagnosis result fed back by the low-side drive module is normal, then the relay is in normal condition. When the first voltage sample value is less than or equal to the fourth voltage threshold, and the fault diagnosis result fed back by the low-side drive module is normal, then the relay is a high-side ground short-circuit fault. When the first voltage sample value is greater than the fifth voltage threshold, and the fault diagnosis result fed back by the low-side drive module is a power supply short circuit fault, then the relay is a low-side power supply short circuit fault.

7. The relay dual-sided drive circuit according to claim 4, characterized in that, When the control signals sent by the processing module to the control terminals of both the high-side drive module and the low-side drive module are disabled signals, and the fault diagnosis result fed back by the low-side drive module is an open circuit fault, the processing module is further used to... Send an enable signal to the low-side driver module and a disable signal to the high-side driver module; Obtain the third voltage sample value of the high-side drive signal at the output terminal of the high-side drive module; When the third voltage sample value is less than or equal to the fifth voltage threshold, the relay is in a normal state; When the third voltage sample value is greater than the fourth voltage threshold but less than or equal to the fifth voltage threshold, the relay is in an open-circuit fault.

8. A method for diagnosing anomalies in a relay bilateral drive circuit as described in any one of claims 1-7, characterized in that, include: Send the same type of control signal to the control terminals of the high-side drive module and the low-side drive module to control the high-side drive module and the low-side drive module to close or open at the same time. Obtain the high-side feedback signal of the high-side driving module and the low-side feedback signal of the low-side driving module; Relay fault diagnosis is performed based on the type of control signal, the high-side feedback signal, and the low-side feedback signal. Wherein, the high-side feedback signal is the first voltage sample value of the high-side drive signal at the output terminal of the high-side drive module, and the low-side feedback signal is the fault diagnosis type fed back by the low-side drive module.

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