Relay double-side driving circuit and abnormity diagnosis method thereof

Abstract

The invention discloses a relay bilateral driving circuit and an abnormality diagnosis method thereof. Control signals of the same type are sent to the control ends of the high-side and low-side driving modules to control the high-side and low-side driving modules to be closed or disconnected at the same time so as to obtain a high-side feedback signal of the high-side driving module and a low-side feedback signal of the low-side driving module. And fault diagnosis of the relay is carried out according to the type of the control signal, the high-side feedback signal and the low-side feedback signal. According to the relay bilateral driving circuit, the problem of misoperation of the relay caused by short circuit or open circuit faults of the output end of the single-side driving circuit can be avoided, fault diagnosis of the relay can be accurately carried out, and the safety and reliability of a vehicle are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of drive circuits, and in particular relates to a relay bilateral drive circuit and an abnormality diagnosis method thereof. Background Art

[0002] Electric vehicles are usually powered by high-voltage power batteries. To meet the needs of the entire vehicle, the battery system needs to provide different power supply circuits. For example, when the vehicle is driving, the discharge circuit needs to be turned on; when the battery is charging, the charging circuit needs to be turned on; when the battery is heated, the heating circuit needs to be turned on. To ensure the control of these different circuits, the high-voltage relays in the control circuits need to be turned on and off according to requirements.

[0003] In the past, relay controllers generally used chip low-side drivers, which were used to drive and diagnose. However, this solution still has some shortcomings: unilateral driving is not conducive to safety and can easily cause relay malfunctions; if the drive line is broken, the relay will not operate. If a short-to-ground fault occurs in the wiring harness, the vehicle will not be able to lower the high voltage and there will be a risk of electric shock. If the wiring harness of the high-voltage relay is misdiagnosed, resulting in abnormally lowered high voltage or failure to raise high voltage, the vehicle will have poor robustness.

[0004] Therefore, it is necessary to design a relay control circuit and diagnostic scheme that is safe, reliable and can avoid misdiagnosis. Summary of the invention

[0005] The purpose of the present invention is to provide a relay bilateral drive circuit and an abnormality diagnosis method thereof. The present application designs a relay bilateral drive circuit and an abnormality diagnosis method thereof, which solves the problem that unilateral drive is not conducive to safety and easily causes relay malfunction and misdiagnosis.

[0006] In order to solve the above technical problems, the present invention provides a relay bilateral driving circuit, the relay bilateral driving circuit comprising:

[0007] Processing module;

[0008] A high-side driver module, whose input end is connected to the driving power supply, the output end is connected to the first end of the relay, and the control end is connected to the processing module, and the high-side driver module is used to control the connection 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, whose input end is connected to the second end of the relay, whose output end is grounded, and whose control end is connected to the processing module, wherein the low-side driving module is used to control the connection 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 used to send the same type of control signals to the control ends of the high-side driver module and the low-side driver module to control the high-side driver module and the low-side driver module to be closed or disconnected at the same time, so as to obtain the high-side feedback signal of the high-side driver module and the low-side feedback signal of the low-side driver module, and perform fault diagnosis of the relay according to the type of the control signal, the high-side feedback signal and the low-side feedback signal;

[0011] Among them, the high-side feedback signal is a first voltage sampling value of the 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 the 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 one embodiment of the present invention, the high-side driver module includes a high-side driver unit and a first pull-up sampling unit;

[0013] The high-side driving unit is used for outputting a high-side driving 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 used to sample the high-side driving signal at the output end of the high-side driving unit to obtain the first voltage sampling value.

[0015] In one embodiment of the present invention, the first pull-up sampling unit includes 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 to the pull-up power supply, and the other end is connected to the output end of the high-side driver module;

[0017] One end of the first pull-down resistor is connected to the output end of the high-side driver module, and the other end of the first pull-down resistor is grounded;

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

[0019] In one embodiment of the present invention, the low-side driving module includes a low-side driving unit and a second pull-up sampling unit;

[0020] The low-side driving unit is used for outputting a low-side driving 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 used to sample the low-side driving signal at the input end of the low-side driving unit to obtain the second voltage sampling value.

[0022] In one embodiment of the present invention, the second pull-up sampling unit includes 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 to the pull-up power supply, and the other end is connected to the input end of the low-side driver module;

[0024] One end of the second pull-down resistor is connected to the input end of the low-side driver module, and the other end of the second pull-down resistor is grounded;

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

[0026] In one embodiment of the present invention, 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] Performing fault diagnosis of the relay according to the type of the control signal, the high-side feedback signal and the low-side feedback signal includes:

[0028] Respectively comparing the first voltage sampling value and the second voltage sampling value with corresponding voltage thresholds to generate a voltage comparison result;

[0029] Fault diagnosis of the relay is performed according to the type of the control signal and the voltage comparison result.

[0030] In one embodiment of the present invention, respectively comparing the first voltage sampling value and the second voltage sampling value with corresponding voltage thresholds to generate a voltage comparison result includes:

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

[0032] Compare the second voltage sampling value 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;

[0033] taking 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 as a voltage comparison result;

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

[0035] In one embodiment of the present invention, when the control signals sent by the processing module to the control terminals of the high-side driver module and the low-side driver 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 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 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, 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, 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 but less than or equal to the third voltage threshold, the relay is in an open circuit fault.

[0040] In one embodiment of the present invention, when the control signals sent by the processing module to the control terminals of the high-side driver module and the low-side driver 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, and the second voltage sampling value is less than the first voltage threshold, 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, 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, the relay is in a low-side power supply short-circuit fault.

[0044] In one embodiment of the present invention, 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 invention, 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 to generate a voltage comparison result;

[0047] Fault diagnosis of the relay 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.

[0048] In one embodiment of the present invention, the first voltage sampling value is compared with a corresponding voltage threshold to generate a voltage comparison result, including:

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

[0050] Among them, the fourth voltage threshold is smaller than the fifth voltage threshold.

[0051] In one embodiment of the present invention, when the control signals sent by the processing module to the control terminals of the high-side driver module and the low-side driver module are both disable signals, the fault diagnosis of the relay 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 driver module, including:

[0052] When the first voltage sampling value is greater than the fourth voltage threshold and less than or equal to the fifth voltage threshold, and the fault diagnosis result fed back by the low-side driver 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 driver module is an open circuit fault, the relay is an open circuit fault;

[0054] When the first voltage sampling value is greater than the fifth voltage threshold, and the fault diagnosis result fed back by the low-side driving module is in 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 a fourth voltage threshold, and the fault diagnosis result fed back by the low-side driving module is a ground short circuit fault, the relay is in a high-side ground short circuit fault and / or a low-side ground fault.

[0056] In one embodiment of the present invention, when the control signals sent by the processing module to the control terminals of the high-side driver module and the low-side driver module are both enable signals, the fault diagnosis of the relay 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 driver module, including:

[0057] When the first voltage sampling value is greater than the fifth voltage threshold, and the fault diagnosis result fed back by the low-side driver 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, and the fault diagnosis result fed back by the low-side driving module is in a normal state, the relay is in a high-side ground short circuit fault;

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

[0060] In one embodiment of the present invention, when the control signals sent by the processing module to the control terminals of the high-side driver module and the low-side driver module are both disable signals, and the fault diagnosis result fed back by the low-side driver module is an open circuit fault, the processing module is further configured to:

[0061] Sending an enable signal to the low-side driver module, and sending a disable signal to the high-side driver module;

[0062] Acquire a third voltage sampling value of the high-side drive signal at the 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, the relay is in a normal state;

[0064] 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 fault.

[0065] In order to achieve the purpose of the present application and other related purposes, the present application also provides an abnormality diagnosis method for a relay bilateral drive circuit as described in any one of the above items, comprising:

[0066] Sending the same type of control signal to the control ends of the high-side driver module and the low-side driver module to control the high-side driver module and the low-side driver module to be closed or disconnected at the same time;

[0067] Acquire a high-side feedback signal of the high-side driver module and a low-side feedback signal of the low-side driver module;

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

[0069] Among them, the high-side feedback signal is a first voltage sampling value of the 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 the 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.

[0070] The relay bilateral driving circuit of the present invention comprises a processing module; a high-side driving module, whose input end is connected to a driving power supply, whose output end is connected to a first end of a relay, and whose control end is connected to the processing module, wherein the high-side driving module is used to control the connection state between the driving power supply and the first end of the relay according to a control signal of the processing module; a low-side driving module, whose input end is connected to a second end of the relay, whose output end is grounded, and whose control end is connected to the processing module, wherein the low-side driving module is used to control the connection state between the second end of the relay and the ground according to a control signal of the processing module; and the processing module is used to send signals to the high-side driving module and the low-side driving module. The control end of the low-side driving module sends the same type of control signal to control the high-side driving module and the low-side driving module to close or disconnect at the same time, so as to obtain the high-side feedback signal of the high-side driving module and the low-side feedback signal of the low-side driving module, and perform fault diagnosis of the relay according to the type of the control signal, the high-side feedback signal and the low-side feedback signal; wherein the high-side feedback signal is the first voltage sampling value of the high-side driving signal at the output end of the high-side driving module, and the low-side feedback signal is the second voltage sampling value of the low-side driving signal at the input end of the low-side driving module, or the fault diagnosis type of the low-side driving module feedback. By using the present application, the problem of relay malfunction caused by short circuit or open circuit fault at the output end of the unilateral driving circuit can be avoided, and the relay fault diagnosis relay bilateral driving circuit can be accurately performed, thereby improving the safety and reliability of the vehicle.

[0071] When the SBC driver chip is used as a low-side driver module, the present invention rechecks the open circuit fault diagnosed by the SBC driver chip when the relay is not driven, thereby avoiding the SBC driver chip falsely reporting an open circuit fault and causing driving abnormality, thereby causing abnormal low high voltage or failure to increase high voltage, thereby improving the robustness of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0073] Figure 1A schematic diagram of a module of a relay bilateral drive circuit provided by an exemplary embodiment of the present application.

[0074] Figure 2 A schematic diagram of the circuit structure of a relay bilateral drive circuit provided as an exemplary embodiment of the present application.

[0075] Figure 3 A schematic diagram of the circuit structure of a relay bilateral drive circuit provided for another exemplary embodiment of the present application. DETAILED DESCRIPTION

[0076] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0077] In order to solve the problem that unilateral driving is not conducive to safety, the relay cannot operate when the driving line fails, and the vehicle cannot be driven under high voltage and there is a risk of electric shock when a short-to-ground fault occurs in the wiring harness, the present invention provides a bilateral driving circuit, and these embodiments will be discussed in detail below.

[0078] It should be understood that the present application only uses the relay as the bilateral driving device as an example for detailed description, and the bilateral driving circuit and diagnostic method thereof of the present application can also be applied to other bilateral driving devices.

[0079] See also Figure 1-3 As shown, in an exemplary embodiment of the present application, the relay bilateral drive circuit includes: a processing module 1, a low-side drive module 2 and a high-side drive module 3, wherein the relay can be a main positive relay, a main negative relay, a pre-charge relay, a charging positive high-voltage relay, a charging negative high-voltage relay, etc.

[0080] Wherein, the high-side driver module 3, its input end (connected to the 12V port) is connected to the 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 driver module 3 is used to control the connection 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 DC power supply, and of course it can also be a 24V DC power supply, a 48V DC power supply or other suitable DC power supplies;

[0081] The low-side driving module 2 has an input end connected to the second end of the relay 4, an output end connected to the ground, and a control end connected to the processing module 1. The low-side driving module 2 is used to control the connection 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 used to send the same type of control signal to the control ends of the high-side driver module 3 and the low-side driver module 2, so as to control the high-side driver module 3 and the low-side driver module 2 to be closed or disconnected at the same time, so as to obtain the high-side feedback signal of the high-side driver module 3 and the low-side feedback signal of the low-side driver module 2, and perform 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] Among them, the high-side feedback signal is a 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 a 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 fed back by the low-side drive module.

[0084] See also Figure 2 As shown, in one embodiment, the high-side driver module 3 includes a high-side driver unit HSD and a first pull-up sampling unit, and the high-side driver unit HSD (High-Side Driver) is connected to the processing module 1, and is used to output a high-side driver 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 connection state between the driving power supply and the first end of the relay 4. The first pull-up sampling unit is connected to the output end of the high-side driver unit HSD and the processing module 1, and is used to sample the high-side driver signal at the output end of the high-side driver module 3 to obtain the first voltage sampling value as a high-side feedback signal, and send it to the processing module 1.

[0085] See also Figure 2 As shown, in one 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 to the pull-up power supply, and the other end of the pull-up resistor R2 is connected to the output end of the high-side driver 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 to the output end of the high-side driver module 3, and the other end of the pull-down resistor R3 is grounded; one end of the feedback resistor R1 is connected to the output end of the high-side driver module 3, and the other end is connected to the processing module 1.

[0086] See also Figure 2 As shown, in one embodiment, the low-side driver module 2 includes a low-side driver unit LSD (Low-Side Driver) and a second pull-up sampling unit, wherein the low-side driver unit LSD is connected to the processing module 1, and is used to connect the output end of the high-side driver module 3 according to the low-side control signal of the processing module 1 to control the connection state between the second end of the relay 4 and the ground. The second pull-up sampling unit is connected to the input end of the low-side driver unit LSD and the processing module 1, and is used to sample the low-side drive signal at the input end of the low-side driver unit LSD to obtain the second voltage sampling value as a low-side feedback signal, and send it to the processing module.

[0087] See also Figure 2 As shown, in one embodiment, the second sampling unit includes 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 to the pull-up power supply, and the other end of the pull-up resistor R5 is connected to the input end of the low-side driver 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 to the input end of the low-side driver module 2, and the other end of the pull-down resistor R6 is grounded; one end of the feedback resistor R4 is connected to the input end of the low-side driver module 2, and the other end is connected to the processing module 1.

[0088] It should be understood that, in the exemplary embodiments 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 may be different, or other sampling circuits may be used for sampling, and the various voltage thresholds described below may be adaptively adjusted.

[0089] See also Figure 2 As shown, in one 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 according to the type of control signal, the high-side feedback signal V H and the low-side feedback signal V L Perform fault diagnosis of relay 4.

[0090] See also Figure 2As shown, in one 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 relay 4 is performed according to the type of 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 the corresponding voltage threshold value respectively to generate a voltage comparison result, and the fault diagnosis of relay 4 is performed according to the type of control signal and the voltage comparison result.

[0091] Specifically, when the first voltage sampling value and the second voltage sampling value are compared with the corresponding voltage thresholds to generate a voltage comparison result, the first voltage sampling value can be compared with the first voltage threshold, the second voltage threshold and the third voltage threshold to determine the voltage interval of the first voltage sampling value; at the same time, the second voltage sampling value is compared with the first voltage threshold, the second voltage threshold and the third voltage threshold to determine the voltage interval of the second voltage sampling value; the voltage interval of the first voltage sampling value and the voltage interval of the second voltage sampling value are taken as the voltage comparison result; wherein 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 corresponding circuit parameters of the pull-up resistor, the pull-down resistor, the feedback resistor of the 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, among which, short circuit to ground (SCG, Short Circuit to Ground) means that the current flows directly from a certain point in the circuit to the ground, bypassing the original circuit path; short circuit to power supply (SCB, Short Circuit to Battery) means that a certain point in the circuit is incorrectly connected to the power supply; open circuit (OL, Open Loop) fault means that current cannot flow through a part of the circuit due to a circuit break or failure.

[0093] When the control signals sent by the processing module 1 to the control terminals of the high-side driver module 3 and the low-side driver module 2 are both disabling signals, that is, when the relay is disconnected, the fault diagnosis of the relay 4 is performed according to the type of the control signal and the voltage comparison result, which may include the following situations:

[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 in a high side power supply short circuit (HSD SCB) fault and / or a low side power supply short circuit (SD 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 in 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 but less than or equal to the third voltage threshold, the relay 4 is in an open circuit (OL) fault.

[0098] When the control signals sent by the processing module to the control terminals of the high-side driver module and the low-side driver module are both enable signals, that is, when the relay is closed, the fault diagnosis of the relay 4 is performed according to the type of the control signal and the voltage comparison result, which may include the following situations:

[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 ground short circuit (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 in a low side power supply short circuit (HSD SCB) fault;

[0102] If the situation does not fall into the above three situations, it means that the circuit has an unexpected abnormality and is judged as an error or other fault.

[0103] Please refer to Table 1. In the exemplary embodiment of the present application, the first voltage threshold, the second voltage threshold, and the third voltage threshold are obtained by measuring and calculating according to the actual circuit experiment of the present application, and are 1V, 3.5V, and 4.6V, respectively. H Represents the first voltage sampling value, V L Of course, in other embodiments, the first voltage threshold, the second voltage threshold, and the third voltage threshold can be other values ​​set corresponding to the circuit.

[0104] Table 1

[0105]

[0106] See also Figure 3 As shown, in another embodiment of the present application, the difference between the bilateral driving circuit and the above exemplary embodiment is: a low-side driving module 2, the low-side driving module is an SBC (System Basis Chip) driving chip, the SBC driving chip is connected to the processing module 1, and communicates with the processing module 1 in a two-way manner, and is used to output a low-side driving signal to the second end of the relay 4 according to the low-side control signal output by the processing module 1, so as to control the connection 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 it 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 relay fault diagnosis.

[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 first compared with the corresponding voltage threshold to generate a voltage comparison result; and then the fault diagnosis of the relay 4 can be 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 to generate a voltage comparison result means comparing the first voltage sampling value with the fourth voltage threshold and the fifth voltage threshold respectively to determine the voltage interval in which the first voltage sampling value is located; wherein the fourth voltage threshold is less than the fifth voltage threshold. It should be noted that the fourth voltage threshold and the fifth 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 resistor, the pull-down resistor, the feedback resistor and other circuit parameters of the corresponding pull-up sampling unit.

[0109] When the control signals sent by the processing module to the control ends of the high-side driver module 3 and the low-side driver module 2 are both disabling signals, that is, when the relay 5 is disconnected, 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 driver module 2, which may include the following situations:

[0110] When the first voltage sampling value is greater than the fourth voltage threshold and less than or equal to the fifth voltage threshold, and the fault diagnosis result fed back by the low-side driver module 2 is a normal state, 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 driver module feedback 2 is an open circuit (OL) fault, the relay 4 is an open circuit (OL) fault;

[0112] When the first voltage sampling value is greater than the fifth voltage threshold, and the fault diagnosis result fed back by the low-side driver module 2 is in a normal state, the relay 4 is in a high-side power supply short circuit (HSD SCB) fault and / or a low-side power supply short circuit (LSD SCB) fault;

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

[0114] When the control signals sent by the processing module to the control terminals of the high-side driver module 3 and the low-side driver module 2 are both enable signals, that is, when 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 fed back by the low-side driver module 2, which may include the following situations:

[0115] When the first voltage sampling value is greater than the fifth voltage threshold, and the fault diagnosis result fed back by the low-side driver module is a normal state, the relay 4 is in a normal state;

[0116] When the first voltage sampling value is less than or equal to the fourth voltage threshold, and the fault diagnosis result fed back by the low-side driver module 2 is in a normal state, the relay 4 is in a high-side short circuit to ground (HSD SCG) fault;

[0117] When the first voltage sampling value is greater than the fifth voltage threshold, and the fault diagnosis result fed back by the low-side driver module 2 is a power supply short circuit (SCB) fault, the relay is a low-side power supply short circuit (LSD SCG) fault;

[0118] If the situation does not fall into the above three situations, it means that the circuit has an unexpected abnormality and is judged as an error or other fault.

[0119] Please refer to Table 2. In another exemplary embodiment of the present application, the fourth voltage threshold and the fifth voltage threshold are obtained by measuring and calculating according to the actual circuit experiment of the present application, and are 1.2V and 4.6V, respectively. H Represents the first voltage sampling value, V L Indicates the second voltage sampling value.

[0120] Table 2

[0121]

[0122] Please refer to Table 3, the present application also provides a verification scheme for false open circuit faults using an SBC driver chip as a low-side driver module 2. Specifically, when the control signals sent by the processing module 1 to the control ends of the high-side driver module 3 and the low-side driver module 2 are both disable signals, that is, the relay 4 is disconnected, and the fault diagnosis result fed back by the low-side driver module 2 is an open circuit (OL) fault, the processing module 1 can also send an enable signal to the low-side driver module 2 and a disable signal to the high-side driver module 3; obtain a third voltage sampling value V of the high-side driver signal at the output end of the high-side driver module 3 H '; When the third voltage sampling value V H ' 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 up the above-mentioned verification scheme for false open circuit faults, a secondary verification can be performed when the SBC driver chip diagnosis result is an open circuit fault, thereby avoiding the SBC driver chip falsely reporting an open circuit fault and causing driving abnormalities, which in turn causes abnormal low high voltage or failure to increase high voltage, thereby improving the robustness of the vehicle.

[0126] In summary, the use of the present application can avoid the problem of relay malfunction caused by a short circuit or open circuit fault at the output end of a unilateral drive circuit, and can accurately perform relay fault diagnosis on the relay bilateral drive circuit, thereby improving the safety and reliability of the vehicle.

[0127] When the SBC driver chip is used as a low-side driver module, the present invention rechecks the open circuit fault diagnosed by the SBC driver chip when the relay is not driven, thereby avoiding the SBC driver chip falsely reporting an open circuit fault and causing driving abnormality, thereby causing abnormal low high voltage or failure to increase high voltage, thereby improving the robustness of the vehicle.

[0128] When the SBC driver chip is used as a low-side driver module, the present invention rechecks the open circuit fault diagnosed by the SBC driver chip when the relay is not driven, thereby avoiding the SBC driver chip falsely reporting an open circuit fault and causing driving abnormality, thereby causing abnormal low high voltage or failure to increase high voltage, thereby improving the robustness of the vehicle.

[0129] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope involved in the present application is not limited to the technical solution formed by a specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the inventive concept, such as a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features with similar functions disclosed in this application.

[0130] Except for the technical features described in the specification, the remaining technical features are known technologies to those skilled in the art. In order to highlight the innovative features of the present invention, the remaining technical features will not be described here in detail.

Claims

1. A relay bilateral drive circuit, characterized in that: include: Processing module; A high-side driver module, whose input end is connected to the driving power supply, the output end is connected to the first end of the relay, and the control end is connected to the processing module, and the high-side driver module is used to control the connection state between the driving power supply and the first end of the relay according to the control signal of the processing module; A low-side driving module, whose input end is connected to the second end of the relay, whose output end is grounded, and whose control end is connected to the processing module, wherein the low-side driving module is used to control the connection state between the second end of the relay and the ground according to the control signal of the processing module; The processing module is used to send the same type of control signals to the control ends of the high-side driver module and the low-side driver module to control the high-side driver module and the low-side driver module to be closed or disconnected at the same time, so as to obtain the high-side feedback signal of the high-side driver module and the low-side feedback signal of the low-side driver module, and perform fault diagnosis of the relay according to the type of the control signal, the high-side feedback signal and the low-side feedback signal; Among them, the high-side feedback signal is a first voltage sampling value of the 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 the 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.

2. The relay bilateral drive circuit according to claim 1, characterized in that: The high-side driving module comprises a high-side driving unit and a first pull-up sampling unit; The high-side driving unit is used for outputting a high-side driving signal to the first end of the relay according to the control signal of the processing module; The first pull-up sampling unit is used to sample the high-side driving signal at the output end of the high-side driving unit to obtain the first voltage sampling value.

3. The relay bilateral driving circuit according to claim 2, characterized in that: The first pull-up sampling unit includes a first feedback resistor, a first pull-up resistor and a first pull-down resistor; One end of the first pull-up resistor is connected to the pull-up power supply, and the other end is connected to the output end of the high-side driver module; One end of the first pull-down resistor is connected to the output end of the high-side driver module, and the other end of the first pull-down resistor is grounded; One end of the first feedback resistor is connected to the output end of the high-side driving module, and the other end is connected to the processing module.

4. The relay bilateral driving circuit according to claim 1, characterized in that: The low-side driving module comprises a low-side driving unit and a second pull-up sampling unit; The low-side driving unit is used for outputting a low-side driving signal to the second end of the relay according to the low-side control signal of the processing module; The second pull-up sampling unit is used to sample the low-side driving signal at the input end of the low-side driving unit to obtain the second voltage sampling value.

5. The relay bilateral driving circuit according to claim 4, characterized in that: The second pull-up sampling unit includes a second feedback resistor, a second pull-up resistor and a second pull-down resistor; One end of the second pull-up resistor is connected to the pull-up power supply, and the other end is connected to the input end of the low-side driver module; One end of the second pull-down resistor is connected to the input end of the low-side driver module, and the other end of the second pull-down resistor is grounded; One end of the second feedback resistor is connected to the input end of the low-side driving module, and the other end is connected to the processing module.

6. The relay bilateral driving circuit according to claim 1, characterized in that: When the high-side feedback signal is the first voltage sampling value and the low-side feedback signal is the second voltage sampling value; Performing fault diagnosis of the relay according to the type of the control signal, the high-side feedback signal and the low-side feedback signal includes: Respectively comparing the first voltage sampling value and the second voltage sampling value with corresponding voltage thresholds to generate a voltage comparison result; Fault diagnosis of the relay is performed according to the type of the control signal and the voltage comparison result.

7. The relay bilateral driving circuit according to claim 6, characterized in that: Respectively comparing the first voltage sampling value and the second voltage sampling value with corresponding voltage thresholds to generate a voltage comparison result, including: Compare the first voltage sampling value with a first voltage threshold, a second voltage threshold and a third voltage threshold respectively to determine a voltage interval in which the first voltage sampling value is located; Compare the second voltage sampling value 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; taking 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 as a voltage comparison result; The first voltage threshold is smaller than the second voltage threshold, and the second voltage threshold is smaller than the third voltage threshold.

8. The relay bilateral driving circuit according to claim 7, characterized in that: When the control signals sent by the processing module to the control terminals of the high-side driver module and the low-side driver module are both disable signals, a fault diagnosis of the relay is performed according to the type of the control signal and the voltage comparison result, including: 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 is in a normal state; When the first voltage sampling value and the second voltage sampling value are both greater than the third voltage threshold, the relay is in a high-side power supply short-circuit fault and / or a low-side power supply short-circuit fault; 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 is in a high-side ground short circuit fault and / or a low-side ground short circuit fault; When the first voltage sampling value is greater than the second voltage threshold but less than or equal to the third voltage threshold, the relay is in an open circuit fault.

9. The relay bilateral driving circuit according to claim 7, characterized in that: When the control signals sent by the processing module to the control terminals of the high-side driver module and the low-side driver module are both enable signals, a fault diagnosis of the relay is performed according to the type of the control signal and the voltage comparison result, including: 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 is in a normal state; 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 is in a high-side ground short circuit fault; When the first voltage sampling value and the second voltage sampling value are both greater than the third voltage threshold, the relay is in a low-side power supply short-circuit fault.

10. The relay bilateral driving circuit according to claim 1, characterized in that: The low-side driving module includes an SBC driving chip, and the SBC driving chip is used to output a low-side driving 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.

11. The relay bilateral driving circuit according to claim 10, characterized in that: Performing fault diagnosis of the relay according to the type of the control signal, the high-side feedback signal and the low-side feedback signal includes: Comparing the first voltage sampling value with a corresponding voltage threshold to generate a voltage comparison result; Fault diagnosis of the relay 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.

12. The relay bilateral driving circuit according to claim 10, characterized in that: Comparing the first voltage sampling value with a corresponding voltage threshold to generate a voltage comparison result, including: Compare the first voltage sampling value with a fourth voltage threshold and a fifth voltage threshold respectively to determine a voltage interval in which the first voltage sampling value is located; Among them, the fourth voltage threshold is smaller than the fifth voltage threshold.

13. The relay bilateral driving circuit according to claim 12, characterized in that: When the control signals sent by the processing module to the control terminals of the high-side driver module and the low-side driver module are both disable signals, the fault diagnosis of the relay 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 driver module, including: When the first voltage sampling value is greater than the fourth voltage threshold and less than or equal to the fifth voltage threshold, and the fault diagnosis result fed back by the low-side driver module is a normal state, the relay is in a normal state; 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 driver module is an open circuit fault, the relay is an open circuit fault; When the first voltage sampling value is greater than the fifth voltage threshold, and the fault diagnosis result fed back by the low-side driving module is in 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; When the first voltage sampling value is less than or equal to a fourth voltage threshold, and the fault diagnosis result fed back by the low-side driving module is a ground short circuit fault, the relay is in a high-side ground short circuit fault and / or a low-side ground fault.

14. The relay bilateral driving circuit according to claim 12, characterized in that: When the control signals sent by the processing module to the control terminals of the high-side driver module and the low-side driver module are both enable signals, the fault diagnosis of the relay 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 driver module, including: When the first voltage sampling value is greater than the fifth voltage threshold, and the fault diagnosis result fed back by the low-side driver module is a normal state, the relay is in a normal state; When the first voltage sampling value is less than or equal to the fourth voltage threshold, and the fault diagnosis result fed back by the low-side driving module is in a normal state, the relay is in a high-side ground short circuit fault; When the first voltage sampling value is greater than the fifth voltage threshold, and the fault diagnosis result fed back by the low-side driving module is a power supply short circuit fault, the relay is in a low-side power supply short circuit fault.

15. The relay bilateral driving circuit according to claim 10, characterized in that: When the control signals sent by the processing module to the control terminals of the high-side driver module and the low-side driver module are both disable signals, and the fault diagnosis result fed back by the low-side driver module is an open circuit fault, the processing module is further used to Sending an enable signal to the low-side driver module, and sending a disable signal to the high-side driver module; Acquire a third voltage sampling value of the high-side drive signal at the output end of the high-side drive module; When the third voltage sampling value is less than or equal to the fifth voltage threshold, the relay is in a normal state; When the third voltage sampling 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.

16. A method for diagnosing abnormality of a relay bilateral drive circuit according to any one of claims 1 to 15, characterized in that: include: Sending the same type of control signal to the control ends of the high-side driver module and the low-side driver module to control the high-side driver module and the low-side driver module to be closed or disconnected at the same time; Acquire a high-side feedback signal of the high-side driver module and a low-side feedback signal of the low-side driver module; Performing fault diagnosis of the relay according to the type of the control signal, the high-side feedback signal and the low-side feedback signal; Among them, the high-side feedback signal is a first voltage sampling value of the high-side driving signal at the output end of the high-side driving module, and the low-side feedback signal is a second voltage sampling value of the low-side driving signal at the input end of the low-side driving module, or a fault diagnosis type fed back by the low-side driving module.

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