Drive fault diagnosis circuit

Abstract

The embodiment of the present invention relates to the field of new energy vehicles, and discloses a drive fault diagnosis circuit. The drive fault diagnosis circuit includes: a drive switch unit and a load circuit connected in series, a first node located at the first end of the load circuit, and a second node located at the second end of the load circuit; and a diagnosis control circuit electrically connected to the first node and / or the second node; the diagnosis control circuit is used to detect the voltage of the first node and / or the voltage of the second node, and determine the fault type according to the detected voltage of the first node or the voltage of the second node. Using the technical solution provided by the present invention, it is possible to detect the cause of the fault in the electric vehicle drive circuit.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of new energy vehicles, and in particular to a drive fault diagnosis circuit. Background Art

[0002] The replacement of fuel vehicles by electric vehicles has become a development trend in the automotive industry, and the high-power switching devices used in electric vehicles, such as relays, contactors, etc., as well as some loads are very important for the safe operation of vehicles. Due to the complex driving environment and the life of the load itself, the above devices may fail, and the cause of the failure is likely to be open circuit, short power supply and short ground faults in the device itself. Therefore, it is particularly important to diagnose the above faults before the load is powered on and report them to the vehicle controller so that some safety measures can be taken.

[0003] In the process of studying the prior art, the inventors found that the traditional fault detection scheme mainly uses the RC voltage divider feedback detection circuit and the characteristics of the triode or MOS tube to detect the fault, and cannot distinguish whether it is a short power supply, short ground, open circuit or the power supply itself. Among them, the RC voltage divider feedback detection circuit also needs to adjust the voltage division ratio according to the internal resistance of the load. In addition, the traditional detection scheme sometimes needs to turn on the load drive circuit, which increases the risk of the load being turned on by mistake. For example, the contactor is not allowed to be closed during the power-on diagnosis process of the contactor. Summary of the invention

[0004] The purpose of the embodiments of the present invention is to provide a drive fault diagnosis circuit, which can detect the cause of the fault of the electric vehicle drive circuit.

[0005] To solve the above technical problems, an embodiment of the present invention provides a driving fault diagnosis circuit, comprising: a driving switch unit and a load circuit connected in series, a first node located at the first end of the load circuit, and a second node located at the second end of the load circuit; and a diagnosis control circuit electrically connected to the first node or the second node; the diagnosis control circuit is used to detect the voltage of the first node or the voltage of the second node, and determine the fault type according to the detected voltage of the first node or the voltage of the second node.

[0006] Compared with the prior art, the embodiments of the present invention can effectively detect the cause of the fault of the electric vehicle drive circuit by detecting the voltage of at least one end of the load circuit in combination with a certain detection strategy.

[0007] Specifically, the drive fault diagnosis circuit further includes: a drive power supply; a power supply output end of the drive power supply is electrically connected to a first end of the load circuit, a second end of the load circuit is electrically connected to a first end of the drive switch unit, and a second end of the drive switch unit is grounded. In this manner, a specific connection of the drive power supply, the load circuit and the drive switch unit in the low-side drive circuit is provided.

[0008] Specifically, the diagnostic control circuit in the driving fault diagnostic circuit includes: a microcontroller (MCU) and a first switch circuit; the first end of the first switch circuit is electrically connected to the first node, the second end of the first switch circuit is electrically connected to the detection end of the microcontroller, and the control end of the first switch circuit is electrically connected to the first control signal output end of the microcontroller; the microcontroller is used to control the first switch circuit to be in a closed state through the first control signal output end, and determine the fault type according to the voltage detected by the detection end.

[0009] In this manner, in the low-side driving circuit, the specific fault type can be determined by detecting the voltage value of the first node when the first switch circuit is in a closed state.

[0010] Specifically, the diagnostic control circuit also includes a second switch circuit; the first end of the second switch circuit is electrically connected to the second node, the second end of the second switch circuit is electrically connected to the detection end of the microcontroller, and the control end of the second switch circuit is electrically connected to the second control signal output end of the microcontroller; the microcontroller is used to: control the first switch circuit to be in a closed state through the first control signal output end, and control the second switch circuit to be in an open state through the second control signal output end.

[0011] Specifically, the microcontroller controls the first switch circuit to be in a closed state through the first control signal output terminal, and controls the second switch circuit to be in an open state through the second control signal output terminal, and the microcontroller determines that the voltage detected by the detection terminal is zero, and then determines that the fault type is a drive power supply fault or a first node short-to-ground fault. In this manner, in the low-side drive circuit, by controlling the coordination of the opening or closing of the first switch circuit and the second switch circuit, a drive power supply fault or a first node short-to-ground fault can be determined.

[0012] Specifically, if the microcontroller controls the first switch circuit to be in a closed state through the first control signal output end, and controls the second switch circuit to be in an open state through the second control signal output end, and the microcontroller determines that the voltage detected by the detection end is not zero, then the microcontroller controls the first switch circuit to be in an open state through the first control signal output end, and controls the second switch circuit to be in a closed state through the second control signal output end, and determines that the voltage detected by the detection end is zero, then the fault type is determined to be an open load or a short circuit to the second node.

[0013] In this manner, in the low-side driving circuit, by controlling the coordination of the opening or closing of the first switch circuit and the second switch circuit, it is possible to determine whether the load is open or the second node is short-circuited to ground.

[0014] Specifically, the diagnostic control circuit also includes a third switching circuit; the first end of the third switching circuit is connected to the detection power supply, the second end of the third switching circuit is connected to the second node, and the control end of the third switching circuit is connected to the third control signal output end of the microcontroller; the microcontroller controls the third switching circuit to be in an off state through the third control signal output end.

[0015] Specifically, the microcontroller is also used to: after determining that the fault type is an open load or a short circuit to the second node, control the first switch circuit to be in an open state through the first control signal output end, and control the second switch circuit to be in a closed state through the second control signal output end, and control the third switch circuit to be in a closed state through the third control signal output end, and determine the fault type based on the voltage detected by the detection end.

[0016] Specifically, if the microcontroller controls the first switch circuit to be in an open state through the first control signal output terminal, and controls the second switch circuit to be in a closed state through the second control signal output terminal, and controls the third switch circuit to be in a closed state through the third control signal output terminal, if the microcontroller determines that the voltage detected by the detection end is zero, then the fault type is determined to be a short circuit to the second node; if it is determined that the voltage detected by the detection end is not zero, then the fault type is determined to be an open load.

[0017] In this manner, in the low-side driving circuit, the second node short-to-ground fault and the load open-circuit fault can be distinguished according to the coordination of the opening or closing of the first switch circuit, the second switch circuit and the third switch circuit.

[0018] Specifically, the drive fault diagnosis circuit also includes a drive power supply; the power supply output end of the drive power supply is electrically connected to the first end of the drive switch unit, the second end of the drive switch unit is electrically connected to the first end of the load circuit, and the second end of the load circuit is grounded. In this method, a specific circuit connection of the drive circuit, the drive switch unit and the load circuit in the high-side drive circuit is provided.

[0019] Specifically, the diagnostic control circuit includes a microcontroller, a first switch circuit, a second switch circuit and a third switch circuit; the first end of the first switch circuit is electrically connected to the first node, the second end of the first switch circuit is electrically connected to the detection end of the microcontroller, and the control end of the first switch circuit is electrically connected to the first control signal output end of the microcontroller; the first end of the second switch circuit is electrically connected to the second node, the second end of the second switch circuit is electrically connected to the detection end of the microcontroller, and the control end of the second switch circuit is electrically connected to the second control signal output end of the microcontroller; the first end of the third switch circuit is connected to the detection power supply, the second end of the third switch circuit is connected to the first node, and the third control signal output end of the microcontroller is electrically connected to the control end of the third switch circuit.

[0020] The microcontroller is specifically used for: controlling the first switch circuit to be in a closed state through the first control signal output end, controlling the second switch circuit to be in an open state through the second control signal output end, controlling the third switch circuit to be in an open state through the third control signal output end, detecting the voltage of the first node when the third switch circuit is in an open state through the detection end, and controlling the third switch circuit to switch to a closed state through the third control signal output end, detecting the voltage of the first node when the third switch circuit is in a closed state through the detection end, and determining the fault type according to the voltage of the first node when the third switch circuit is in an open state and the voltage of the first node when the third switch circuit is in a closed state.

[0021] In this manner, in the high-side driving circuit, the voltage of the first node is detected in coordination with the switching states of the first switch circuit, the second switch circuit and the third switch circuit, so that the fault type can be determined according to the voltage of the first node.

[0022] Specifically, the microcontroller is used to: if it is determined that the voltage of the first node is greater than zero when the third switch circuit is in an open state, then the fault type is determined to be a load short to power; if it is determined that the voltage of the first node is equal to zero when the third switch circuit is in an open state, and it is determined that the voltage of the first node is still equal to zero when the third switch circuit is in a closed state, then the fault type is determined to be a load short to ground.

[0023] In this manner, in the high-side driving circuit, the voltage of the first node when the third switch circuit is open or closed can be used to distinguish between a load short-to-power fault and a load short-to-ground fault.

[0024] Specifically, the microcontroller is also used for: if it is determined that the voltage of the first node is equal to zero when the third switch circuit is in the open state, and it is determined that the voltage of the first node is not equal to zero when the third switch circuit is in the closed state, then after controlling the first switch circuit to switch from the closed state to the open state through the first control signal output end, the second switch circuit is controlled to switch from the open state to the closed state through the second control signal output end; if the voltage of the second node detected by the detection end is greater than zero, it is determined that the fault type is ground loss, and if it is determined that the voltage of the second node detected by the detection end is equal to zero, it is determined that there is no fault.

[0025] In this manner, in the high-side driving circuit, the microprocessor can detect a ground line loss fault by controlling the opening or closing of the third switch circuit, the first switch circuit, and the second switch circuit.

[0026] Specifically, the diagnostic control circuit also includes a signal filtering unit, an input end of the signal filtering unit is electrically connected to the second end of the first switching circuit and the second end of the second switching circuit, and an output end of the signal filtering unit is electrically connected to the detection end of the microcontroller. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0028] Figure 1 is a schematic diagram of the structure of a driving fault diagnosis circuit according to a first embodiment of the present invention;

[0029] Figure 2 is a schematic structural diagram of a drive fault diagnosis circuit according to a second embodiment of the present invention;

[0030] Figure 3 is a schematic structural diagram of a diagnostic control circuit according to a second embodiment of the present invention;

[0031] Figure 4 is a schematic structural diagram of another diagnosis control circuit according to a second embodiment of the present invention;

[0032] Figure 5 is a schematic structural diagram of a diagnostic control circuit according to a third embodiment of the present invention;

[0033] Figure 6 is a schematic structural diagram of a low-side driver fault diagnosis circuit according to a fourth embodiment of the present invention;

[0034] Figure 7 is a schematic diagram of a fault diagnosis process according to a fourth embodiment of the present invention;

[0035] Figure 8 is a schematic structural diagram of a drive fault diagnosis circuit according to a fifth embodiment of the present invention;

[0036] Fig. 9 is a schematic structural diagram of a diagnosis control circuit according to a fifth embodiment of the present invention;

[0037] Fig.10 is a schematic diagram of a fault diagnosis process according to a fifth embodiment of the present invention;

[0038] Fig.11 is a schematic structural diagram of a drive fault diagnosis circuit according to a sixth embodiment of the present invention;

[0039] Fig.12 is a schematic structural diagram of a drive fault diagnosis circuit according to a seventh embodiment of the present invention;

[0040] Fig.13 is a schematic diagram of a driving fault diagnosis process according to a seventh embodiment of the present invention;

[0041] Fig.14 4 is a schematic diagram of the structure of a high-side driver fault diagnosis circuit according to an eighth embodiment of the present invention. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the following will be described in detail with reference to the accompanying drawings. However, it will be appreciated by those skilled in the art that in the various embodiments of the present invention, many technical details are provided in order to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical scheme claimed in the present application can be implemented.

[0043] It should be noted that in the following embodiments of the present invention, the terms "first", "second", etc. are only used to distinguish nouns, and do not represent order, nor are they used to indicate or imply relative importance. In addition, "including" is an open limitation and does not have the meaning of "only including".

[0044] In a first embodiment of the present invention, a driving fault diagnosis circuit is provided. Figure 1As shown, the drive fault diagnosis circuit includes a drive switch unit 101 and a load circuit 102, a first node 103 located at the first end of the load circuit 102, and a second node 104 located at the second end of the load circuit 102; and a diagnosis control circuit 105 electrically connected to the first node 103 or the second node 104.

[0045] It should be noted that the driving switch unit 101 is electrically connected to the load circuit 102. Figure 1 The example shown in the figure is that the driving switch unit 101 is electrically connected to the second end of the load circuit 102 . Of course, the driving switch unit 101 can also be electrically connected to the first end of the load circuit 102 .

[0046] The diagnosis control circuit 105 is used to detect the voltage of the first node 103 or the voltage of the second node 104 , and determine the fault type according to the detected voltage of the first node 103 or the voltage of the second node 104 .

[0047] In this implementation, by detecting the voltage at at least one end of the load circuit and combining with a certain detection strategy, the cause of the fault in the electric vehicle drive circuit can be effectively detected.

[0048] A second embodiment of the present invention relates to a drive fault diagnosis circuit for detecting the fault type of a battery low-side drive circuit in an electric vehicle. The drive switch unit 101 in this embodiment is a low-side drive unit. The implementation details of the fault diagnosis circuit are described in detail below. The following content is only for the convenience of understanding the implementation details of this solution and is not necessary for implementing this solution.

[0049] Figure 2 The structure diagram of the low-side driver fault diagnosis circuit in this embodiment is shown. Compared with the first embodiment, the low-side driver fault diagnosis circuit further includes a driver power supply 106. The power supply output end of the driver power supply 106 is electrically connected to the first end of the load circuit 102, the second end of the load circuit 102 is electrically connected to the first end of the driver switch unit 101, and the second end of the driver switch unit is grounded.

[0050] Specifically, in the low-side drive fault diagnosis circuit, the load circuit 102 and the drive switch unit 101 are connected in series with the drive power supply 106 in sequence, the first node 103 is located between the drive power supply 106 and the load circuit 102, the second node 104 is located between the load circuit 102 and the drive switch unit 101, and the diagnosis control circuit 105 is electrically connected to the first node 103 and / or the second node 104.

[0051] It should be noted that the diagnostic control circuit 105 electrically connected to the first node 103 and / or the second node 104 means that the diagnostic control circuit 105 can be electrically connected to any one of the first node 103 and the second node 104, or can be electrically connected to the first node 103 and the second node 104 at the same time.

[0052] The diagnostic control circuit 105 is used to detect the voltage of the first node 103 or the voltage of the second node 104 of the driving circuit during the operation of the electric vehicle, and determine the fault type according to the detected voltage of the first node 103 or the voltage of the second node 104 .

[0053] In a specific implementation, the specific structure of the diagnosis control circuit 105 is as follows: Figure 3 As shown, it includes a microcontroller 301 and a first switch circuit 302 .

[0054] The first end of the first switch circuit 302 is electrically connected to the first node 103, the second end of the first switch circuit 302 is electrically connected to the detection end of the microcontroller 301, and the control end of the first switch circuit 302 is electrically connected to the first control signal output end of the microcontroller 301. The microcontroller 301 controls the first switch circuit 302 to be in a closed state through the first control signal output end, and determines the fault type according to the voltage detected by the detection end.

[0055] In a specific implementation, the diagnosis control circuit 105 includes, in addition to the microcontroller 301 and the first switch circuit 302, a second switch circuit 303. A first end of the second switch circuit 303 is electrically connected to the second node 104, a second end of the second switch circuit 303 is electrically connected to the detection end of the microcontroller 301, and a control end of the second switch circuit 303 is electrically connected to the second control signal output end of the microcontroller 301.

[0056] When the microcontroller 301 controls the first switch circuit 302 to be in a closed state through the first control signal output terminal, the microcontroller 301 controls the second switch circuit 303 to be in an open state through the second control signal output terminal.

[0057] Specifically, if the microcontroller 301 controls the first switch circuit 302 to be in a closed state through the first control signal output terminal, and controls the second switch circuit 303 to be in an open state through the second control signal output terminal, and the microcontroller 301 determines that the voltage detected by the detection end is zero, then the fault type is determined to be a fault in the driving power supply 106 or a short circuit to the first node 103.

[0058] If the microcontroller 301 controls the first switch circuit 302 to be in a closed state through the first control signal output terminal, and controls the second switch circuit 303 to be in an open state through the second control signal output terminal, and the microcontroller 301 determines that the voltage detected by the detection terminal is not zero, then the microcontroller 301 controls the first switch circuit 302 to be in an open state through the first control signal output terminal, and controls the second switch circuit 303 to be in a closed state through the second control signal output terminal, and determines that the voltage detected by the detection terminal is zero, then the fault type is determined to be an open load or a short circuit to the second node 104.

[0059] It should be noted that the first switch circuit 302 is used to control the on / off of the electrical connection between the first node 103 and the microcontroller 301, and the second switch circuit 303 is used to control the on / off of the electrical connection between the second node 104 and the microcontroller 301. Through the cooperation of the first switch circuit 302 and the second switch circuit 303, the microcontroller 301 can detect the voltage of the first node 103 or the second node 104, and then perform fault diagnosis based on the detected voltage.

[0060] Through this analysis, it can be understood that the present embodiment does not limit the specific implementation form of the first switch circuit 302 and the second switch circuit 303. It only needs to be able to realize the on-off control of the branch. Specifically, it can be realized by using switch elements such as relays and transistors controlled by the microcontroller 301.

[0061] In a specific implementation, the diagnosis control circuit 105 further includes a signal filtering unit 401, such as Figure 4 As shown, the input end of the signal filtering unit 401 is electrically connected to the second end of the first switch circuit 302 and the second end of the second switch circuit 303 , and the output end of the signal filtering circuit 401 is electrically connected to the detection end of the microcontroller 301 .

[0062] The signal filtering unit 401 may be located inside the microcontroller 301 or outside the microcontroller 301. The figure takes the signal filtering unit 401 outside the microcontroller as an example. It should be noted that by filtering the detected voltage signal of the first node 103 or the second node 104 and performing fault diagnosis based on the filtered voltage signal of the first node 103 or the second node 104, the accuracy of the diagnosis result can be improved.

[0063] In this implementation, a diagnostic control circuit is provided to detect the voltage of the first node or the second node in the low-side drive circuit. Based on the detected voltage of the first node, a drive power supply failure or a short-to-ground condition of the first node can be detected. Based on the detected voltage of the second node, an open load or a short-to-ground condition of the second node can be detected. This allows the vehicle controller to take corresponding safety measures based on the detected fault type, thereby providing the possibility of further improving the safety of the operation of the electric vehicle.

[0064] The third embodiment of the present invention relates to a drive fault diagnosis circuit for detecting the fault type of the battery low-side drive circuit in an electric vehicle. The third embodiment is substantially the same as the second embodiment, with the main difference being that the diagnosis control circuit 105 may further include a third switch circuit 501, the specific structure of which is as follows: Figure 5 As shown, including:

[0065] The first end of the third switch circuit 501 is connected to the detection power supply 502, the second end of the third switch circuit 501 is connected to the second node 104, and the control end of the third switch circuit 501 is connected to the third control signal output end of the microcontroller 301; the microcontroller 301 controls the third switch circuit 501 to be in the disconnected state through the third control signal output end.

[0066] Among them, in the diagnostic control circuit 105 including the third switch circuit 501, after the microcontroller 301 determines that the fault type is an open load or a short circuit to the second node 104, it controls the first switch circuit 302 to be in an open state through the first control signal output end, and controls the second switch circuit 303 to be in a closed state through the second control signal output end, and controls the third switch circuit 501 to be in a closed state through the third control signal output end, and determines the fault type according to the voltage detected by the detection end.

[0067] It should be noted that the driving power supply 106 and the detection power supply 502 may be the same power supply or different power supplies. The third switch circuit 501 is used to control the on / off of the electrical connection between the second node 104 and the microcontroller 301, and through cooperation with the first switch circuit 302 and the second switch circuit 303, the microcontroller can detect the voltage of the first node 103 or the second node 104, and then perform fault diagnosis according to the detected voltage.

[0068] Specifically, the microcontroller 301 controls the first switch circuit 302 to be in an open state through the first control signal output terminal, controls the second switch circuit 303 to be in a closed state through the second control signal output terminal, and controls the third switch circuit 501 to be in a closed state through the third control signal output terminal. If the voltage detected by the detection end of the microcontroller 301 is zero, it can be determined that the fault type is a short circuit of the second node 104; if the voltage detected by the detection end of the microcontroller 301 is not zero, it can be determined that the fault type is an open circuit of the load.

[0069] Through this analysis, it can be understood that the present embodiment does not limit the specific implementation forms of the first switch circuit 302, the second switch circuit 303 and the third switch circuit 501, as long as they can realize the on-off control of the branches. The third switch circuit can be implemented by using switch elements such as relays and triodes controlled by the microcontroller 301.

[0070] The fourth embodiment of the present invention relates to a low-side driver fault diagnosis circuit, which is based on a specific circuit implementation of the third embodiment. Figure 6 As shown:

[0071] The low-side driving unit in the circuit diagram is a driving switch unit; the node T1 in the circuit diagram represents the first node 103, and the node T2 in the circuit diagram represents the second node 104. The switch K1, the resistor R3 and the diode D1 in the circuit diagram together constitute the third switch circuit 501. The following components in the circuit diagram constitute the diagnosis control circuit 105: switch K2, switch K3, switch K1, resistor R3, diode D1 and MCU, wherein switch K2 represents the first switch circuit 302, switch K3 represents the second switch circuit 303, and switch K1, diode D1 and resistor R3 constitute the third switch circuit 501. The P2 terminal of the MCU in the circuit diagram is the first control signal output terminal for controlling K2, the P3 terminal is the second control signal output terminal for controlling K3, the P1 terminal is the third control signal output terminal for controlling K1, and LSD1 is the fourth control signal output terminal for controlling the low-side driving unit.

[0072] According to Figure 7 The flowchart shown is specifically divided into the following steps to determine the fault type of the circuit:

[0073] In step 601 , the MCU controls the switch K2 to be closed, the switch K3 to be opened, and the switch K1 to be opened, and then step 602 is executed.

[0074] In step 602, it is determined whether the voltage of the T1 node detected by the MCU is zero; if the voltage of the T1 node detected by the MCU is zero, step 603 is executed; if the voltage of the T1 node detected by the MCU is greater than zero, step 604 is executed.

[0075] In step 603, it is determined that the fault is a driving power supply fault or a short to ground of the T1 node.

[0076] In step 604 , the MCU controls the switch K2 to be turned off, and then the switch K3 is closed after the switch K1 is turned off, and step 605 is executed.

[0077] In step 605 , it is determined whether the voltage of the T2 node detected by the MCU is zero; if the voltage of the T2 node detected by the MCU is greater than zero, step 606 is executed; if the voltage of the T2 node detected by the MCU is equal to zero, step 607 is executed.

[0078] In step 606, it is determined that the circuit has no faults, and this fault diagnosis process ends.

[0079] In step 607 , the MCU controls the switch K2 to be opened, the switch K3 to be closed, and the switch K1 to be closed, and then step 608 is executed.

[0080] In step 608 , it is determined whether the voltage of the T2 node detected by the MCU is zero; if it is not equal to zero, step 609 is executed; if it is equal to zero, step 610 is executed.

[0081] In step 609 , it is determined that the fault is a load open circuit fault.

[0082] In step 610, it is determined that the fault is a short-to-ground fault at the T2 node.

[0083] This embodiment is a specific circuit implementation based on the third embodiment. In the specific implementation, there may also be other different circuit implementations. This embodiment is only an example, and other specific circuit implementations not described are also within the protection scope of the present invention.

[0084] A fifth embodiment of the present invention relates to a drive fault diagnosis circuit for detecting the fault type of a battery high-side drive circuit in an electric vehicle. The implementation details of the drive fault diagnosis circuit in this embodiment are described in detail below. The following content is only for the convenience of understanding the implementation details of this solution and is not necessary for implementing this solution.

[0085] Figure 8The structure diagram of the driving fault diagnosis circuit in this embodiment is shown, which specifically includes: a driving power supply 106, a driving switch unit 101 and a load circuit 102, wherein the power supply output end of the driving power supply 106 is electrically connected to the first end of the driving switch unit 101, the second end of the driving switch unit 101 is electrically connected to the first end of the load circuit 102, and the second end of the load circuit 102 is grounded. And a first node 103 located at the first end of the load circuit 102, a second node 104 located at the second end of the load circuit 102, and a diagnosis control circuit 105 electrically connected to the first node 103 and / or the second node 104.

[0086] The diagnosis control circuit 105 is used to detect the voltage of the first node 103 or the second node 104 , and determine the fault type according to the detected voltage of the first node 103 or the detected voltage of the second node 104 .

[0087] In a specific implementation, the specific structure of the diagnosis control circuit 105 is as follows: Fig. 9 As shown, it includes a microcontroller 301 , a first switch circuit 302 , a second switch circuit 303 and a third switch circuit 501 .

[0088] The first end of the first switch circuit 302 is electrically connected to the first node 103 , the second end of the first switch circuit 302 is electrically connected to the detection end of the microcontroller 301 , and the control end of the first switch circuit 302 is electrically connected to the first control signal output end of the microcontroller 301 .

[0089] A first end of the second switch circuit 303 is electrically connected to the second node 104 , a second end of the second switch circuit 303 is electrically connected to a detection end of the microcontroller 301 , and a control end of the second switch circuit 303 is electrically connected to a second control signal output end of the microcontroller 301 .

[0090] A first end of the third switch circuit 501 is connected to the detection power supply 502 , a second end of the third switch circuit 501 is connected to the first node 103 , and a third control signal output end of the microcontroller 301 is electrically connected to a control end of the third switch circuit 501 .

[0091] The microcontroller 301 controls the first switch circuit 302 to be in a closed state through the first control signal output terminal, controls the second switch circuit 303 to be in an open state through the second control signal output terminal, controls the third switch circuit 501 to be in an open state through the third control signal output terminal, detects the voltage of the first node 103 when the third switch circuit 501 is in an open state through the detection terminal, and controls the third switch circuit 501 to be in a closed state through the third control signal output terminal, and detects the voltage of the first node 103 when the third switch circuit 501 is in a closed state through the detection terminal. The microcontroller 301 determines the fault type according to the voltage of the first node 103 when the third switch circuit 501 is in an open state and the voltage of the first node 103 when the third switch circuit 501 is in a closed state.

[0092] Specifically, if the microcontroller 301 determines that the voltage of the first node 103 is greater than zero when the third switch circuit 501 is in the open state, the fault type is determined to be a load short to power; if it is determined that the voltage of the first node 103 is equal to zero when the third switch circuit 501 is in the open state, and it is determined that the voltage of the first node 103 is still equal to zero when the third switch circuit 501 is in the closed state, the fault type is determined to be a load short to ground.

[0093] It should be noted that when the first switch circuit 302 is in a closed state and the second switch circuit 303 is in an open state, fault diagnosis is performed by detecting the voltage of the first node of the third switch circuit 501 in different states. It can be understood from this analysis that the present embodiment does not limit the specific implementation form of the first, second and third switch circuits, and only needs to be able to realize the on-off control of the branch, which can be realized by using switch elements such as relays and triodes controlled by the microcontroller 301.

[0094] In this implementation, a diagnostic control circuit is provided to detect the voltage of the first node in the high-side drive circuit. A load short power fault or a load short ground fault can be detected based on the detected voltage of the first node, so that the vehicle controller can take corresponding safety measures based on the detected fault type, thereby providing the possibility of further improving the safety of the operation of the electric vehicle.

[0095] According to Fig.10 The flowchart of the fault diagnosis process shown is specifically divided into the following steps to determine the fault type of the circuit:

[0096] In step 1001, the MCU controls the first switch circuit 302 to be closed, the second switch circuit 303 to be opened, and the third switch circuit 501 to be opened;

[0097] In step 1002, the MCU determines whether the voltage of the first node detected is zero; if the voltage of the first node detected by the MCU is greater than zero, step 1003 is executed; if the voltage of the first node detected by the MCU is equal to zero, step 1004 is executed;

[0098] In step 1003, the MCU determines that the fault is a short supply to the load;

[0099] In step 1004, the MCU controls the third switch circuit 501 to close;

[0100] In step 1005, the MCU determines that the voltage of the detected first node is zero, and determines that the fault is a load short to ground. Otherwise, this diagnosis process ends.

[0101] The sixth embodiment of the present invention relates to a driving fault diagnosis circuit, which is substantially the same as the fifth embodiment, and the main improvements are:

[0102] If the microcontroller 301 determines that the voltage of the first node 103 is equal to zero when the third switch circuit 501 is in the open state, and determines that the voltage of the first node 103 is not equal to zero when the third switch circuit 501 is in the closed state, then after controlling the first switch circuit 302 to switch from the closed state to the open state through the first control signal output end, the second switch circuit 303 is controlled to switch from the open state to the closed state through the second control signal output end; if the voltage of the second node 104 detected by the detection end is greater than zero, it is determined that the fault type is ground loss; if it is determined that the voltage of the second node 104 detected by the detection end is equal to zero, it is determined that there is no fault.

[0103] In a specific implementation, Fig.11 As shown, the drive fault diagnosis circuit also includes a signal filtering unit 1101, the input end of the signal filtering unit 1101 is electrically connected to the second end of the first switch circuit 302 and the second end of the second switch circuit 303, and the output end of the signal filtering unit 1101 is electrically connected to the detection end of the microcontroller 301. Of course, the signal filtering unit 1101 can be located inside the microcontroller 301 or outside the microcontroller 301. The figure shows the situation where it is located outside the microcontroller 301, and the situation where it is located inside the microcontroller 301 is not shown in the figure. It should be noted that by filtering the detected voltage signal of the first node 103 or the second node 104, and performing fault diagnosis based on the filtered voltage signal of the first node 103 or the second node 104, the accuracy of the diagnosis result can be improved.

[0104] This embodiment does not limit the specific implementation forms of the first switch circuit 302, the second switch circuit 303 and the third switch circuit 501, as long as they can realize the on-off control of the branches.

[0105] The seventh embodiment of the present invention relates to a driving fault diagnosis circuit, which is based on a specific circuit implementation of the sixth embodiment. Fig.12 shown.

[0106] The node T1 in the circuit diagram represents the first node 103, the switch K1, the resistor R3 and the diode D1 in the circuit diagram together form the third switch circuit 501, the switch K2 represents the first switch circuit 302, the switch K3 represents the second switch circuit 303, and the node T2 represents the second node 104. The P1 terminal of the MCU represents the third control signal output terminal of the microcontroller 301, the P2 terminal of the MCU represents the first control signal output terminal of the microcontroller 301, the P3 terminal of the MCU represents the second control signal output terminal of the microcontroller 301, and the ADC terminal in the circuit diagram represents the detection terminal of the microcontroller 301. The high-side drive unit in the circuit diagram represents the drive switch unit 101.

[0107] like Fig.13 As shown, the fault type of the circuit is determined according to the following steps:

[0108] In step 1301, the MCU controls switch K1 to be opened, switch K3 to be opened, and switch K2 to be closed;

[0109] In step 1302, the MCU determines whether the voltage of the T1 node detected is zero; if the voltage of the T1 node detected by the MCU is greater than zero, step 1303 is executed; if the voltage of the node T1 detected by the MCU is equal to zero, step 1304 is executed;

[0110] In step 1303, it is determined that the fault is a short supply to the load;

[0111] In step 1304, the MCU controls the switch K1 to close, the switch K3 to open, and the switch K2 to close, and then executes step 1305;

[0112] In step 1305, the MCU determines whether the voltage of the T1 node detected is zero; if the voltage of the T1 node detected by the MCU is equal to zero, step 1306 is executed; if the voltage of the node T1 detected by the MCU is not equal to zero, step 1307 is executed;

[0113] In step 1306, the MCU determines that the fault is a load short to ground;

[0114] In step 1307, the MCU controls the switch K1 to close, the switch K2 to open, and then the switch K3 to close, and then step 1308 is executed;

[0115] In step 1308, determine whether the voltage of the T2 node detected by the MCU is zero; if the voltage of the T2 node detected by the MCU is greater than zero, execute step 1310, that is, determine that the fault is a ground loss fault; if the voltage of the T2 node detected by the MCU is equal to zero, execute step 1309, that is, determine that the circuit has no fault.

[0116] This embodiment of the present invention is a specific circuit implementation based on the sixth embodiment. In the specific implementation, there may also be other different circuit implementations. This case is just an example, and other specific circuit implementations not described are also within the protection scope of the present invention.

[0117] The eighth embodiment of the present invention relates to a drive fault diagnosis circuit, which is a specific circuit implementation of the sixth embodiment. In this embodiment, Fig.14 As shown, the power supply V1 in the circuit represents the driving power supply 106, the HSD in the circuit diagram represents the high-side driving unit, that is, the driving switch unit 101, the load resistor R in the circuit diagram represents the load circuit 102, and the switch S1, the resistor R1, the switch S2, the resistor R3, the switch S3, and the resistor R4, the resistor R5, the resistor R6 and the capacitor C1 in the circuit constitute the diagnosis control circuit 105. The switch S1 and the resistor R1 in the circuit constitute the third switch circuit 501; the switch S2 and the resistor R3 in the circuit constitute the first switch circuit 302; the switch S3, the resistor R4 and the resistor R5 in the circuit constitute the second switch circuit 303, and the resistor R6 and the capacitor C1 constitute the filtering unit 1101; the power supply V2 in the circuit diagram represents the detection power supply 502, and V3 represents the detection end of the microcontroller 301. The specific diagnostic strategy of the circuit is as follows:

[0118] The MCU controls switch S1 to be disconnected, switch S3 to be disconnected, and switch S2 to be closed to determine whether the voltage at the MCU detection end is zero; if the voltage at the MCU detection end is greater than zero, it is determined that the fault is a load short-circuit power supply Vs. At this time, the voltage value calculation formula at the MCU detection end is as follows: V3 = Vs*(R5 / (R3+R5)). Among them, the power supply Vs referred to by the load short-circuit power supply can be a driving power supply, a detection power supply, or other power supplies. If the voltage at the MCU detection end is equal to zero, the MCU controls switch S1 to be closed, switch S3 to be disconnected, and switch S2 to be closed to determine whether the voltage at the MCU detection end is zero. If the voltage at the MCU detection end is equal to zero, it is determined that the fault is a load short-circuit ground; if the voltage at the MCU detection end is not equal to zero, the MCU controls switch S1 to be closed, switch S2 to be disconnected, and then switch S3 to be closed. Determine whether the voltage at the MCU detection end is zero; if the voltage at the MCU detection end is greater than zero, determine that the fault is a ground loss fault. At this time, the voltage value calculation formula of the MCU detection end is as follows: V3=V2*(R5 / (R1+R+R4+R5)); if the voltage at the MCU detection end is equal to zero, determine that the circuit has no fault.

[0119] This embodiment is a specific circuit implementation based on the sixth embodiment. In the specific implementation, there may also be other different circuit implementations. This embodiment is only an example, and other specific circuit implementations not described are also within the protection scope of the present invention.

[0120] It should be noted that, considering that the detection end of the microcontroller is affected by sampling errors, transmission line impedance, software calculation errors and other factors, in the above implementation modes, the voltage of the first node or the second node detected by the detection end is zero, which should be understood as the voltage value detected by the detection end fluctuating around the zero value. Assuming the fluctuation value is Vb, the voltage value detected by the detection end ranges from -Vb to Vb, and the voltage value detected by the detection end is determined to be zero.

[0121] Furthermore, in the above embodiments, the first node and the second node may be a detection end of a common microcontroller, or may respectively use different detection ends of the microcontroller, that is, the first node is electrically connected to the first detection end of the microcontroller, and the second node is electrically connected to the second detection end of the microcontroller.

[0122] In addition, it should be noted that the above embodiments do not limit the specific form of the load circuit 102 , and it can be any electronic component that can serve as a load for a low-side drive circuit or a high-side drive circuit.

[0123] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present invention, and in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present invention.

Claims

1. A drive fault diagnosis circuit, characterized in that: include: A driving switch unit and a load circuit connected in series, a first node located at a first end of the load circuit, and a second node located at a second end of the load circuit; and a diagnostic control circuit electrically connected to the first node and / or the second node; The diagnostic control circuit is used to detect the voltage of the first node or the voltage of the second node, and determine the fault type according to the detected voltage of the first node or the voltage of the second node; In the case where the drive fault diagnosis circuit is used to detect the fault type of the low-side drive circuit, the drive fault diagnosis circuit further comprises: a drive power supply; The power supply output end of the driving power supply is electrically connected to the first end of the load circuit, the second end of the load circuit is electrically connected to the first end of the driving switch unit, and the second end of the driving switch unit is grounded; The diagnostic control circuit includes: a microcontroller and a first switch circuit; The first end of the first switch circuit is electrically connected to the first node, the second end of the first switch circuit is electrically connected to the detection end of the microcontroller, and the control end of the first switch circuit is electrically connected to the first control signal output end of the microcontroller; The microcontroller is used to: control the first switch circuit to be in a closed state through the first control signal output terminal, and determine the fault type according to the voltage detected by the detection terminal; The diagnostic control circuit also includes a second switch circuit; The first end of the second switch circuit is electrically connected to the second node, the second end of the second switch circuit is electrically connected to the detection end of the microcontroller, and the control end of the second switch circuit is electrically connected to the second control signal output end of the microcontroller; The microcontroller is used to: when the first switch circuit is controlled to be in a closed state through the first control signal output terminal, the second switch circuit is controlled to be in an open state through the second control signal output terminal; If the microcontroller controls the first switch circuit to be in a closed state through the first control signal output terminal, and controls the second switch circuit to be in an open state through the second control signal output terminal, and the microcontroller determines that the voltage detected by the detection terminal is not zero, The microcontroller controls the first switch circuit to be in an open state through the first control signal output terminal, and controls the second switch circuit to be in a closed state through the second control signal output terminal, and determines that the voltage detected by the detection terminal is zero, then determines that the fault type is a load open circuit or a second node short-circuited to ground; The diagnostic control circuit further includes a third switch circuit; The first end of the third switch circuit is connected to the detection power supply, the second end of the third switch circuit is connected to the second node, and the control end of the third switch circuit is connected to the third control signal output end of the microcontroller; wherein the third switch circuit comprises a switch, a diode and a resistor, the first end of the switch is connected to the detection power supply, the second end of the switch is connected to the first end of the diode, the second end of the diode is connected to the first end of the resistor, and the second end of the resistor is connected to the second node; The microcontroller controls the third switch circuit to be in an off state through the third control signal output terminal; The microcontroller is also used to: After determining that the fault type is an open load or a short to ground of the second node, controlling the first switch circuit to be in an open state through the first control signal output terminal, controlling the second switch circuit to be in a closed state through the second control signal output terminal, and controlling the third switch circuit to be in a closed state through the third control signal output terminal, and determining the fault type according to the voltage detected by the detection terminal; If the microcontroller controls the first switch circuit to be in an open state through the first control signal output terminal, controls the second switch circuit to be in a closed state through the second control signal output terminal, and controls the third switch circuit to be in a closed state through the third control signal output terminal, If the microcontroller determines that the voltage detected by the detection end is zero, the fault type is determined to be the second node short-to-ground; if the microcontroller determines that the voltage detected by the detection end is not zero, the fault type is determined to be the load open circuit.

2. The drive fault diagnosis circuit according to claim 1, characterized in that: If the microcontroller controls the first switch circuit to be in a closed state through the first control signal output terminal, and controls the second switch circuit to be in an open state through the second control signal output terminal, and the microcontroller determines that the voltage detected by the detection terminal is zero, then the fault type is determined to be a drive power supply failure or a short circuit to the first node.

3. The drive fault diagnosis circuit according to claim 1, characterized in that: In the case where the drive fault diagnosis circuit is used to detect the fault type of the high-side drive circuit, the drive fault diagnosis circuit further includes a drive power supply; The power supply output end of the driving power supply is electrically connected to the first end of the driving switch unit, the second end of the driving switch unit is electrically connected to the first end of the load circuit, and the second end of the load circuit is grounded; The diagnostic control circuit includes a microcontroller, a first switch circuit, a second switch circuit and a third switch circuit; The first end of the first switch circuit is electrically connected to the first node, the second end of the first switch circuit is electrically connected to the detection end of the microcontroller, and the control end of the first switch circuit is electrically connected to the first control signal output end of the microcontroller; The first end of the second switch circuit is electrically connected to the second node, the second end of the second switch circuit is electrically connected to the detection end of the microcontroller, and the control end of the second switch circuit is electrically connected to the second control signal output end of the microcontroller; A first end of the third switch circuit is connected to a detection power supply, a second end of the third switch circuit is connected to the first node, and a third control signal output end of the microcontroller is electrically connected to a control end of the third switch circuit; The microcontroller is specifically used for: When the first switch circuit is controlled to be in a closed state by the first control signal output terminal and the second switch circuit is controlled to be in an open state by the second control signal output terminal, The third switch circuit is controlled to be in an open state through the third control signal output terminal, the voltage of the first node when the third switch circuit is in an open state is detected through the detection terminal, and the third switch circuit is controlled to switch to a closed state through the third control signal output terminal, the voltage of the first node when the third switch circuit is in a closed state is detected through the detection terminal, and the fault type is determined according to the voltage of the first node when the third switch circuit is in an open state and the voltage of the first node when the third switch circuit is in a closed state.

4. The drive fault diagnosis circuit according to claim 3, characterized in that: The microcontroller is specifically used for: If it is determined that the voltage of the first node is greater than zero when the third switch circuit is in the disconnected state, then the fault type is determined to be a load short supply; If it is determined that the voltage of the first node is equal to zero when the third switch circuit is in the open state, and it is determined that the voltage of the first node is still equal to zero when the third switch circuit is in the closed state, the fault type is determined to be a load short to ground.

5. The drive fault diagnosis circuit according to claim 4, characterized in that: The microcontroller is also used to: If it is determined that the voltage of the first node is equal to zero when the third switch circuit is in an open state, and it is determined that the voltage of the first node is not equal to zero when the third switch circuit is in a closed state, then After controlling the first switch circuit to switch from a closed state to an open state through the first control signal output terminal, controlling the second switch circuit to switch from an open state to a closed state through the second control signal output terminal; If the voltage of the second node detected by the detection end is greater than zero, the fault type is determined to be ground loss; if the voltage of the second node detected by the detection end is determined to be zero, it is determined that there is no fault.

6. The drive fault diagnosis circuit according to any one of claims 1, 3 to 5, characterized in that: The diagnostic control circuit also includes a signal filtering unit, an input end of the signal filtering unit is electrically connected to the second end of the first switch circuit and the second end of the second switch circuit, and an output end of the signal filtering unit is electrically connected to the detection end of the microcontroller.

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