Method and device for diagnosing contactor

Abstract

The invention provides a method and a device for diagnosing a contactor. The method includes obtaining a control feedback signal of the contactor, a contactor command status, and fault bit data, determining whether the contactor is in a fault status, and determining at least one of a type and a location of the fault status if the contactor is in the fault status. According to the method, combined diagnosis and information fusion can be carried out on the high-side and low-side driving controlled contactors, more comprehensive monitoring on the contactors is realized, and an ideal function safety level is met.

Description

Technical Field

[0001] This disclosure relates to signal processing and control, and more particularly to methods, apparatus, computer-readable storage media, and computer program products for diagnosing contactors driven by a combination of high and low sides. Background Technology

[0002] In vehicle systems such as electric vehicles, high-voltage control systems are used to control and adjust the state of high-voltage contactors that supply power and operate the vehicle's high-voltage bus. Traditional contactor control schemes are based on a high-side drive (HSD) unilateral control method, and contactor-related diagnostic strategies rely entirely on the diagnostic capabilities of the high-side drive side. Overall, this diagnostic method can only provide simple feedback diagnostics on the contactor's on and off states, i.e., it only determines whether the contactor is open or closed.

[0003] As automotive high-voltage control systems place increasingly stringent requirements on the design and performance reliability of high-voltage contactors, a control method has emerged that adjusts the contactor state through a combined high-side drive and low-side drive (LSD). However, synchronous control of high and low side drives still relies on high and low side control feedback signals as the primary source of information for diagnostics, and cannot adequately cover the diagnostics of the contactor's control side.

[0004] Contactors controlled unilaterally on the high-side drive side can only provide feedback on the control status from the vehicle's overall control system. Their reliability is low, and they are prone to misjudgments or missed diagnoses. For example, if a short circuit to the power supply in a contactor controlled by the high-side drive signal cannot be accurately diagnosed, it may be difficult to detect the defect and perform timely repairs. In extreme cases, the contactor may engage unexpectedly, leading to unpredictable consequences.

[0005] When using a contactor with high-low side drive and bilateral control, simply identifying the loop current of the control feedback signal cannot avoid misjudgment and missed judgment. Therefore, it may not meet the diagnostic coverage requirements of the functional safety level (such as ASIL B), and thus there is still a risk of potential functional safety failure.

[0006] Therefore, there is a need to improve the diagnostic strategies for contactors. Summary of the Invention

[0007] To address at least one of the problems mentioned above, this disclosure proposes a method and apparatus for diagnosing contactors specifically for high- and low-side drive control, so as to achieve more comprehensive monitoring of the contactors and meet the desired functional safety level through joint high- and low-side diagnosis and fusion.

[0008] According to one aspect of this disclosure, a method for diagnosing a contactor controlled by a high-side drive control signal from a high-side drive unit and a low-side drive control signal from a low-side drive unit is proposed. The method includes: acquiring a control feedback signal of the contactor, a contactor command status, and fault position data; determining whether the contactor is in a fault state based on the control feedback signal and the contactor command status; and, if the contactor is in a fault state, determining at least one of the type and location of the fault state based on the control feedback signal, the contactor command status, and the fault position data.

[0009] According to another aspect of this disclosure, an apparatus for diagnosing a contactor is provided, the contactor being controlled by a high-side drive control signal from a high-side drive unit and a low-side drive control signal from a low-side drive unit. The apparatus includes: a high-side drive unit and a low-side drive unit, configured to provide the high-side drive control signal and the low-side drive control signal, respectively, for controlling the contactor, and to provide fault position data of the contactor; and a diagnostic unit, configured to acquire a control feedback signal, a contactor command status, and the fault position data of the contactor; determine whether the contactor is in a fault state based on the control feedback signal and the contactor command status; and, if the contactor is in a fault state, determine at least one of the type and location of the fault state based on the control feedback signal, the contactor command status, and the fault position data.

[0010] According to another aspect of this disclosure, a computer-readable storage medium is provided on which a computer program is stored, the computer program including executable instructions that, when executed by a processor, implement the method described above.

[0011] According to another aspect of this disclosure, an electronic device is provided, including a processor and a memory for storing executable instructions of the processor, the processor being configured to execute the executable instructions to implement the method described above.

[0012] According to another aspect of this disclosure, a computer program product is provided, comprising a computer program that, when executed by a processor, implements the method described above.

[0013] According to another aspect of this disclosure, a vehicle is provided, including a device for diagnosing a contactor as described above.

[0014] The diagnostic strategy proposed in the embodiments of this disclosure enables joint diagnosis and information fusion of the high and low side drive control designs, providing more comprehensive and effective monitoring for dual-side drive contactors. Based on different contactor failure scenarios, control failures on the high and low side drive channels can be summarized, allowing for more precise differentiation and identification of diagnostic scenarios, and the design of diagnostic logic strategies and algorithms with broader coverage. Through related combined control, ideal functional safety level requirements (e.g., ASIL B level) can be achieved. Using this diagnostic strategy at the vehicle level can prevent invalid diagnosis, missed diagnosis, and misdiagnosis at the contactor drive control end. Screening for erroneous diagnostic scenarios makes it easier to locate and troubleshoot problems and formulate corresponding solutions during development and after-sales stages. Attached Figure Description

[0015] The above and other features and advantages of this disclosure will become more apparent from a detailed description of exemplary embodiments thereof with reference to the accompanying drawings.

[0016] Figure 1 This is a schematic signal connection diagram of a system for controlling the state of a high-voltage bus contactor according to an embodiment of the present disclosure.

[0017] Figure 2 This is a schematic diagram of the current loop in the process of using a high-low side combined drive control contactor according to an embodiment of the present disclosure.

[0018] Figure 3 This is a schematic diagram of the current loop in the process of using a high-side single-side drive control contactor according to an embodiment of the present disclosure.

[0019] Figure 4 This is a schematic diagram of a fault state to be diagnosed during the use of a high-low side combined drive control contactor according to an embodiment of the present disclosure.

[0020] Figure 5 This is a schematic flowchart of a method for diagnosing a contactor according to an embodiment of the present disclosure.

[0021] Figure 6 This is a schematic structural block diagram of an apparatus for diagnosing contactors according to an embodiment of the present disclosure.

[0022] Figure 7 This is a schematic block diagram of an electronic device according to an embodiment of the present disclosure. Detailed Implementation

[0023] Exemplary embodiments will now be described more fully in conjunction with the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to make the disclosure comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. In the drawings, the dimensions of some elements may be exaggerated or modified for clarity. The same reference numerals in the drawings denote the same or similar structures, and therefore their detailed description will be omitted.

[0024] Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to enhance a full understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure may be practiced without one or more of the specific details described, or other methods, elements, etc., may be employed. In other instances, basic or well-known structures, methods, or operations are not shown or described in detail to avoid obscuring various aspects of this disclosure.

[0025] The control scenarios mentioned in this disclosure can be, for example, in vehicles such as new energy vehicles, where the power supply and operation of vehicle equipment connected to the busbar are controlled by adjusting the state of contactors that can turn on and off the high-voltage busbar. Generally, contactor elements are used in high-voltage environments to turn on and off high-voltage buses or lines. In vehicle control systems, controllers (and further microcontrollers) such as application-specific integrated circuits (ASICs), DSPs, etc., are typically used to receive and transmit control and data signals in low-voltage environments using power supply and drive voltages such as 12V or lower. In the contactor diagnostic scenario exemplified in this disclosure, the corresponding type and number of contactors can be selected at the contact points (switching points) on the corresponding busbars based on the high-voltage control system and its corresponding bus type and number to isolate the low-voltage and high-voltage environments. According to embodiments of this disclosure, the controller can control and switch the state of the contactors by driving them. The contactors can be driven unilaterally by a single drive control signal (generally a high-side drive control signal), or driven synchronously by a combination of a high-side drive control signal and a low-side drive control signal. Generally, in the case of bilateral joint drive, when both the high-side drive control signal and the low-side drive control signal simultaneously drive the contactor to the closed state, the contactor will remain or change to the closed state according to its previous state. The corresponding bus contact (switching point) will be turned on to allow current to flow through the contactor. At this time, the command of the drive control signal driving the contactor is "ON / OFF (or value 1)", which can also be described as the contactor command state being "ON" or "ON" for controlling the contactor to close. Conversely, when at least one of the two drive control signals drives the contactor to the open state, the contactor will remain or change to the open state according to its previous state. The corresponding bus contact (switching point) will not be turned on, preventing current from flowing through the contactor. At this time, the command of the drive control signal driving the contactor to the open state is "OFF / OFF (or value 0)", which can also be described as the contactor command state being "OFF" or "OFF" for controlling the contactor to open. Alternatively, both the high-side drive control signal and the low-side drive control signal with the contactor command for the closed state can be provided to the contactor simultaneously. According to embodiments of this disclosure, the controller can also perform the corresponding functions through other components and methods that are different from contactors and capable of receiving weak current control signals to drive the contactor points (switching points) in a strong current environment to turn on and off.

[0026] Depending on the type of vehicle equipment being controlled, the controller implementing the high-low side drive control function may include a microcontroller (MCU) of the high-voltage control system of the vehicle drive system or a controller or microcontroller of another vehicle subsystem. These vehicle subsystems include, but are not limited to, vehicle drive systems, battery charging (fast charging and normal charging) systems, braking systems, safety systems, air conditioning systems, entertainment systems, navigation systems, and accessory systems. These high-voltage control systems can respectively control the on / off of the high-voltage buses that supply power and operate vehicle equipment such as drive motors, power batteries, and charging equipment. Those skilled in the art will understand that the solutions disclosed herein are not limited to using vehicle controllers to diagnose contactors used in the power supply and functional operation of corresponding buses, but can also be applied to the diagnosis of contactors in other vehicles, as well as the diagnosis of contactors in other equipment and systems that use contactors to control the power supply and operation of high-voltage buses. This disclosure uses the example of diagnosing the fault state of a contactor whose state is adjusted by high-low side drive control signals in the high-voltage control system of a vehicle drive system to illustrate the technical details of the solution; however, the application scenarios of the solutions disclosed herein are not limited to this.

[0027] Below, in conjunction with Figure 1 A schematic signal connection diagram is provided for a system for controlling the state of a high-voltage contactor on a high-voltage bus according to an embodiment of the present disclosure.

[0028] The number of drive units can be selected based on the number of signal output channels or ports provided by the ASIC used, the number of contactors and their terminals to be controlled, and the number and type of high-side and low-side drive control signals required. In this example, due to factors such as cost and power consumption, the chip constituting HSD unit 110 provides two signal outputs, and the chips constituting LSD units 120 and 130 each provide two signal outputs. Depending on the control scenario applied, more chips can be selected to implement HSD and LSD units. This system uses one high-side drive HSD unit 110 and two low-side drive LSD units 120 and 130 to implement high- and low-side drive control functions to adjust the closing / closing states of the main contactor HV on the high-voltage bus of the vehicle drive system and the DC fast-charging contactor (also referred to as fast-charging contactor) DC on the charging circuit of the battery charging system. The main contactor HV includes a main positive contactor HV+ and a main negative contactor HV- with two switching points respectively located on the positive and negative high-voltage buses. When contactors HV+ and HV- are simultaneously closed, the high-voltage bus and the motor form a closed discharge circuit to provide energy to the motor. The fast-charging contactor DC includes a fast-charging positive contactor DC+ and a fast-charging negative contactor DC-, with two switching points respectively located on the positive and negative voltage buses of the charging line. When contactors DC+ and DC- are simultaneously closed, the charging bus and the battery pack form a closed charging circuit to provide energy to the battery pack. Generally, the combination of contactors HV+ and HV- is used in scenarios where electrical energy is output externally, while the combination of contactors DC+ and DC- is used in scenarios where the battery pack is charged internally. The microcontroller (MCU) can provide a high-side enable signal (corresponding to SPI1) to the HSD unit 110 and a low-side enable signal (corresponding to SPI2 and SPI3) to the LSD units 120 and 130 via its SPI ports SPI1, SPI2, and SPI3 to trigger and control the corresponding drive units. In the embodiments of this disclosure, the main positive contactor HV+ and the fast-charging positive contactor DC+ share the same high-side drive control signal for driving, while the main negative contactor HV- and the fast-charging negative contactor DC- share another high-side drive control signal for driving. Therefore, the HSD unit 110 can be implemented using a single chip with two signal outputs. On the low-side drive side corresponding to the main positive contactor HV+ and the fast-charging positive contactor DC+, a single LSD unit 120 is used to drive them in charging and discharging scenarios using two low-side drive control signals respectively. On the low-side drive side of the main negative contactor HV- and the fast-charging negative contactor DC-, another LSD unit 130 is used to drive them in charging and discharging scenarios using two low-side drive control signals respectively.

[0029] According to embodiments of this disclosure, the main contactor HV and the fast-charging contactor DC are controlled separately. That is, at any given time, the SPI enable signal can only control the main positive contactor HV+ and the main negative contactor HV- of the main contactor HV, or the fast-charging positive contactor DC+ and the fast-charging negative contactor DC- of the fast-charging contactor DC. A pre-charging contactor can be configured to work in conjunction with the contactors. Taking the main contactor HV as an example, during the high-voltage process of an electric vehicle, the pre-charging contactor can be closed first, then the main negative contactor HV- of the main contactor HV can be closed, and finally the main positive contactor HV+ can be closed. During the high-voltage process, the main positive contactor HV+ can be opened first, followed by the main negative contactor HV-. By adhering to this asynchronous control sequence on the high-side and low-side drive sides, simultaneous closure of the contactors can prevent the high current in the high-voltage circuit from damaging the on-board equipment. This document primarily discusses the power-on and power-off scenarios of the main contactor HV and the fast-charging contactor DC.

[0030] The SPI enable signal can be a full-duplex signal, sending control commands to the HSD and LSD units during normal operation. The SPI enable signal can be used to control each driver-side channel independently or synchronously. The following example focuses on controlling a driver-side channel independently. Additionally, SPI enable signal transmission can also be used to read the status of registers (e.g., fault registers) in the HSD / LSD unit chip in real time for real-time monitoring of fault occurrences.

[0031] HSD unit 110 receives a high-side enable signal from the SPI1 port of the MCU via high-side enable signal receiver port 116. The high-side enable signal can trigger HSD unit 110 to operate and instruct it to provide two contactor high-side drive control signals through high-side drive control signal ports 113 and 115 to drive the contactor and implement high-side drive control function. The two high-side drive control signal ports can use the same configuration. For example, high-side drive control signal port 113 can be implemented using a built-in controlled switching element such as a transistor. The current carrying capacity of the HSD unit is approximately 2A. If an external load with a larger rated current is used, an external MOSFET device can also be used in conjunction with the built-in controlled switching element. The high-side drive control signal power supply port 112 receives a constant active high-side drive control power supply signal Vbat (e.g., 16V DC) from the power control unit or battery pack. The high-side enable signal receiving port 116, in response to the received high-side enable signal, instructs the HSD unit 110 to output a first-path contactor high-side drive control signal for driving the contactor to maintain or change its state through the high-side drive control signal port 113. When the high-side enable signal is valid, it triggers and instructs the HSD unit 110 to output a first-path contactor high-side drive control signal for driving the contactor to maintain its closed state through port 113. At this time, the high-side drive control signal power supply port 112 and the high-side drive control signal port 113 are connected, causing port 113 to output the high-level high-side drive control power supply signal from port 112 as the first-path contactor high-side drive control signal to the corresponding contactor (HV+ or DC+). When the microcontroller (MCU) outputs an invalid high-side enable signal, the high-side drive control signal power supply port 112 and the high-side drive control signal port 113 are disconnected, causing port 113 to output a low-level first contactor high-side drive control signal. The high-side enable signal can be set to be active low.

[0032] Based on a similar configuration to ports 112 and 113, HSD unit 110, in response to a high-side enable signal received via high-side enable signal receiving port 116, instructs HSD unit 110 to output a second contactor high-side drive control signal at high-side drive control signal port 115 for driving the contactor to maintain or change the contactor state. High-side drive control signal power supply port 114 also receives a constant active high-side drive control power supply signal Vbat (e.g., 16V DC) provided by a power control unit or battery pack. The signal logic of port 115, which outputs the second contactor high-side drive control signal, is similar to that of port 113; that is, when the high-side enable signal is valid, it triggers and instructs HSD unit 110 to output a high-level second contactor high-side drive control signal via port 115 for driving the contactor HV- or DC- to maintain the closed state; when the high-side enable signal is invalid, port 115 outputs a low-level second contactor high-side drive control signal.

[0033] The first high-side contactor drive control signal is used to drive the main positive contactor HV+ or the fast-charging positive contactor DC+ to adjust the state of the corresponding contactor. The second high-side contactor drive control signal is used to drive the main negative contactor HV- or the fast-charging negative contactor DC- to adjust the state of the corresponding contactor. According to embodiments of this disclosure, the first and second high-side contactor drive control signals can use the same control signal to drive the corresponding contactor to remain in a closed / open state or change from one state to another.

[0034] The system can provide control feedback signals for monitoring and diagnosing the high-side drive control function of the contactor. The first and second high-side drive control signals output from ports 113 and 115 are respectively converted into an active first high-side control feedback signal 117A and a second high-side control feedback signal 117B. These two high-side control feedback signals can be input to a microcontroller (MCU) or other controller to monitor and diagnose the high-side drive control function of the contactor and obtain the current status of the contactor. Analog voltage signals of the high-side drive control signals can be used as control feedback signals. Ports 113 and 115 of the HSD unit 110 can also be connected to the high-side drive side of the corresponding contactor using a standardized signal interface 140.

[0035] On the low-side drive side of the contactor, LSD units 120 and 130 are used to implement the low-side drive control function of the contactor. Figure 1 The embodiment shown employs two LSD units, wherein LSD unit 120 may be referred to as the first LSD unit and LSD unit 130 may be referred to as the second LSD unit.

[0036] The first LSD unit 120 mainly provides contactor low-side drive control signals for driving the main positive contactor HV+ or the fast-charging positive contactor DC+ to change the state of the corresponding contactor. The low-side enable signal receiving port 126 of the first LSD unit 120 receives a first low-side enable signal from the SPI2 port of the microcontroller MCU. In response to the received low-side enable signal, the first LSD unit 120 outputs contactor low-side drive control signals for driving the main positive contactor HV+ or the fast-charging positive contactor DC+ through the low-side drive control signal ports 122 and 123, respectively, thereby realizing the contactor low-side control function of maintaining or changing the state of the corresponding contactor.

[0037] The low-side drive control signal port 122 of the first LSD unit 120 can be implemented using a controlled switching element. For example, in an example using a built-in transistor as the controlled switching element, the low-side drive control signal power supply port (not shown) receives an active low-side drive control power supply signal from a power control unit or battery pack. Based on a valid first low-side enable signal received by the low-side enable signal receiving port 126 from port SPI2 of the microcontroller MCU, the first LSD unit 120 is triggered, controlling the low-side drive control signal power supply port and the low-side drive control signal port 122 to conduct, causing port 122 to output a low level (e.g., 0 potential of GND) as a low-level first contactor low-side drive control signal that keeps or changes the DC+ of the fast charging positive contactor to a closed state. The first low-side enable signal can be set to be active low. When the first low-side enable signal is an invalid high level, the low-side drive control signal power supply port of the first LSD unit 120 is disconnected from the low-side drive control signal port 122, causing port 122 to output a high-level (e.g., 2.5V DC) first contactor low-side drive control signal to the fast-charging positive contactor DC+, resulting in its state remaining open or changing to open. The low-side drive control signal port 123 of the first LSD unit 120 adopts a similar configuration to port 122, for example, implementing the output of a second contactor low-side drive control signal from the low-side drive control signal port 123 based on the received first low-side enable signal, so as to drive the main positive contactor HV+ to control its state. According to embodiments of this disclosure, the first and second contactor low-side drive control signals can use similar control signals, which can adjust the corresponding contactors to remain closed / open or change from one state to another in internal charging scenarios that provide energy to the battery pack and external discharging scenarios that provide energy to the motor, respectively.

[0038] It should be noted that when HSD unit 110 and the first LSD unit 120 use corresponding high-side and low-side drive control signals to control the high-side and low-side drive sides of the same contactor (e.g., main positive contactor HV+ or fast-charging positive contactor DC+), they can simultaneously control the first high-side drive control signal and the second low-side drive control signal to be closed / open (i.e., HSD ON and LSD ON), causing the main positive contactor HV+ to immediately engage. In actual operation, there may be a time difference of approximately 10ms between HSDON and LSD ON. This is because synchronous control of HSD unit 110 and the first LSD unit 120 may cause false alarms due to transient current effects. Therefore, asynchronous control with a reserved interval is more effective than synchronous control of the high-side and low-side drive control signals.

[0039] To monitor and diagnose whether the contactor low-side drive control function of the first and second contactor low-side drive control signals output from ports 122 and 123 of the first LSD unit 120 is normal, the contactor low-side drive control signals output from ports 122 and 123 can be separated into an active first contactor low-side control feedback signal 127A and a second contactor low-side control feedback signal 127B. The control feedback signals 127A and 127B can use analog current signals. Similarly, standardized signal interfaces 140 can be respectively set between ports 122 and 123 and the corresponding contactor low-side drive sides.

[0040] The second LSD unit 130 is mainly used to provide contactor low-side drive control signals for driving the main negative contactor HV- or the fast-charging negative contactor DC-. The low-side enable signal receiving port 136 of the second LSD unit 130 receives a second low-side enable signal from the SPI3 port of the MCU. In response to the received low-side enable signal, the second LSD unit 130 outputs contactor low-side control signals for driving the fast-charging negative contactor DC- and the main negative contactor HV- through the low-side drive control signal ports 132 and 133, respectively, thereby realizing the contactor low-side drive control function of maintaining or changing the state of the corresponding contactor.

[0041] Similar to the first LSD unit 120, the low-side drive control signal port 132 of the second LSD unit 130 can be implemented using a controlled switching element. For example, in an example using a built-in transistor as the controlled switch, the low-side drive control signal power supply port (not shown) receives an active low-side drive control power supply signal from a power control unit or battery pack. Based on a valid second low-side enable signal received from port SPI3 of the microcontroller MCU received by the low-side enable signal receiving port 136, the second LSD unit 130 is triggered, controlling the low-side drive control signal power supply port and the low-side drive control signal port 132 to conduct, causing port 132 to output a low level (e.g., 0 potential at GND) as a third contactor low-side drive control signal that keeps or changes the DC- of the fast-charging negative contactor to a closed state. The second low-side enable signal can be set to be active low. When the second low-side enable signal is an invalid high level, the low-side drive control signal power supply port of the second LSD unit 130 is disconnected from the low-side drive control signal port 132, causing port 132 to output a high-level (e.g., 2.5VDC) third contactor low-side drive control signal to the fast-charging negative contactor DC-, so that the state of the fast-charging negative contactor DC- remains or changes to open. The low-side drive control signal port 133 of the second LSD unit 130 adopts a similar configuration to port 132, for example, to implement the output of a fourth contactor low-side drive control signal from the low-side drive control signal port 133 based on the received second low-side enable signal, so as to drive the main negative contactor HV- to control its state. According to embodiments of this disclosure, the third and fourth contactor low-side drive control signals can use similar control signals, which can drive the corresponding contactors to remain closed / open or change from one state to another in the internal charging scenario of providing energy to the battery pack and the external discharging scenario of providing energy to the motor, respectively.

[0042] Similar to the first LSD unit 120, when the HSD unit 110 and the second LSD unit 130 output corresponding contactor high-side and low-side drive control signals to control the high-side drive side and low-side drive side of the same contactor (e.g., main negative contactor HV- or fast-charging negative contactor DC-), asynchronous control can also be used instead of synchronous control to obtain better control effect.

[0043] To monitor and diagnose the normal operation of the contactor low-side drive control function of the third and fourth contactor low-side drive control signals output from ports 132 and 133 of the second LSD unit 130, active third contactor low-side control feedback signal 137A and fourth contactor low-side control feedback signal 137B can be generated from the contactor low-side drive control signals output from ports 132 and 133. The control feedback signals 137A and 137B can use analog current signals. Similarly, standardized signal interfaces 140 can be set between ports 132 and 133 and the corresponding contactor low-side drive sides.

[0044] from Figure 1 As shown in the system signal connections, the control of contactors (especially high-voltage contactors) is crucial for electric vehicles. Monitoring the control effectiveness of the high-voltage control system directly determines whether the vehicle can operate stably and output power. With increasing safety requirements for electric vehicles, higher control demands are being placed on contactors. For example, mainstream OEMs now require high-voltage contactors to meet at least ASIL B level shutdown functionality. ASIL B level safety functions require accurate identification and diagnosis of failed circuits, and in the event of a failure, the control system and vehicle must promptly enter a safe state (e.g., disconnect the circuit) to prevent personal injury (such as high-voltage electric shock or battery pack fire).

[0045] Based on the customer's requirement for ASIL B level shut-off control of high-voltage contactors, it is necessary to design the contactor's drive strategy using a dual-sided control method with high and low side drive, and design the corresponding diagnostic logic and algorithm for the contactor based on this drive strategy.

[0046] The main purpose of contactor diagnostics is to confirm that the contactor executes or maintains the predetermined opening / closing or closing / disconnecting action under the drive of a predetermined drive control signal, and to detect any abnormal situations where the contactor fails to respond to the predetermined control strategy. While determining whether the predetermined drive control command is executed, it is also necessary to determine the reason for unsuccessful or erroneous execution, i.e., to provide feedback on whether there are any electrical failures in the current drive control circuit that could lead to a fault. Fault states include several types of faults such as short-to-power (SCP), short-to-ground (SCG), and open-loop-open-load (OL) in the drive control circuit.

[0047] The following will be combined with the appendix Figure 2 and 3This paper introduces the characteristics and differences of contactor diagnostic principles in single-sided control using high-side drive and double-sided control using high-low-side drive. Figure 2 The current loop shown is in the process of using a high-low side dual-sided joint drive contactor. Figure 3 The current loops shown in the process of using a high-side single-sided driven contactor are all based on Figure 1 The signal connection diagram of the system shown involves the part used to adjust the main positive contactor HV+. The main positive contactor HV+ is used as the diagnostic object for analysis, and the diagnostic principle of other contactors is similar.

[0048] The prerequisite for an electromagnetic contactor to open / close (engage) is that there is a load-rated current flowing through the electromagnetic coil, such as... Figure 2 and 3 The current is shown in thick lines to illustrate the normal pull-in process. Figure 2 In the high-low side (dual-sided) control method, port 113 of the high-side drive side (e.g., from the area control unit ZCU terminal) outputs a 12VDC drive potential (from a power source such as a power control unit or battery pack), while port 123 of the low-side drive side outputs a 0 potential (GND). This forms a current loop from port 113, through the main positive contactor HV+, to port 123. The current flowing in the loop causes the load electromagnetic coil of the main positive contactor HV+ to operate, generating an electromagnetic field. Figure 3 In the high-side (single-side) control mode, the high-side drive side (e.g., from the electronic control unit ECU) outputs a 12VDC drive potential (also from the power supply such as the power control unit or battery pack) at port 113, while the 0 potential (GND) is provided by the vehicle's ground terminal, thus forming a current loop from port 113, the main positive contactor HV+ to the vehicle's ground terminal. The current flowing in this loop causes the load electromagnetic coil to operate to generate an electromagnetic field.

[0049] Based on the above description of normal operation scenarios, faults that disrupt the normal operation of high-side and low-side drive control are essentially faults that disrupt the aforementioned current loops. These faults include, for example, short circuits to power supply, short circuits to ground, and open circuits on the high-side drive (HSD) side, and short circuits to power supply, short circuits to ground, and open circuits on the low-side drive (LSD) side. The HSD and LSD sides can be distinguished by the electromagnetic coil load of the contactor. Similarly, faults that disrupt the normal operation of single-side (high-side) drive control only include short circuits to power supply, short circuits to ground, and open circuits on the high-side drive (HSD) side. The most significant difference between single-side (high-side) drive control and double-side drive control is that the GND (0 potential) of single-side control is provided by the entire vehicle and is always stable, while the GND (0 potential) of high-low-side double-side drive control requires the low-side drive control signal channel of the LSD unit to be driven (the contactor is in the ON state of open / closed) before it can be provided; otherwise, the low-side drive control signal on the low-side drive side of the contactor will output a potential of approximately 2.5VDC.

[0050] According to embodiments of this disclosure, for high-side and low-side dual-sided drive control, a weak 5V DC pull-up power supply can be provided within the chips of the HSD and LSD units to the high-side drive (HSD) and low-side drive (LSD) channels. When the corresponding channel is in the OFF state (off / open), the 5V DC is output to the external load circuit. Based on the voltage divider principle, voltage changes occur at the voltage sampling points within the chip due to open or short circuits in the external circuit. By comparing the voltage at the voltage sampling points, it can be determined whether there is a problem with the external circuit. When the corresponding channel is in the ON state (on / closed), it is equivalent to the controlled switching elements within the HSD and LSD unit chips being closed. The shunt resistor built into the chip can collect the current value flowing through the circuit in real time and compare it with a preset threshold current using a current comparator. If the collected current exceeds the threshold current, an overcurrent fault is determined. For the high-side drive HSD channel side, an overcurrent means that side is short-circuited to ground; for the low-side drive LSD channel side, an overcurrent means that side is short-circuited to the power supply.

[0051] The diagnostic accuracy of the single-sided high-side (HSD) in different fault scenarios depends on whether a stable GND can be provided, while the diagnostic accuracy of the single-sided low-side (LSD) in different fault scenarios depends on whether a stable 12V DC can be provided. For example, when the single-sided high-side is detected in the OFF state, if the low-side does not have an ON state (i.e., provide GND), an open-circuit (OL) fault will be detected on the high-side. Similarly, if the low-side is detected in the OFF state, and the high-side does not have an ON state (i.e., provide GND), an open-circuit (OL) fault will be detected on the low-side. However, in reality, no open-circuit fault occurs in the circuit loop in the above two cases. This is a diagnostic limitation caused by the series connection of the high-side driver and the low-side driver.

[0052] Therefore, both single-sided drive control (e.g., high-side drive) and double-sided drive control (e.g., high-low-side drive) of contactors can lead to incorrect judgments of fault states. Incorrect judgments include false positives or false negatives, where false negatives include the following situations:

[0053] - When the contactor is in the ON state (open / closed), the high-side drive side of the contactor is short-circuited to the power supply (HSDSCP). At this time, it is impossible to distinguish whether the 12VDC is provided by port 113 of HSD unit 110 or by the short-circuit power supply (Vbat).

[0054] - When the contactor is in the ON state (open / closed), the high-side drive side of the contactor is open (HSD OL). Due to the inherent limitations of the integrated chip, the existence and location of the open circuit cannot be diagnosed.

[0055] - When the contactor is in the OFF state (closed / open), the high-side drive side of the contactor is short-circuited to ground (HSDSCG);

[0056] (The following omissions only exist in the dual-drive control mode:)

[0057] - When the contactor is in the ON state (open / closed), the low-side drive side of the contactor is short-circuited to ground (LSD SCG);

[0058] - When the contactor is in the ON state (open / closed), the low-side drive side of the contactor is open (LSD OL);

[0059] - When the contactor is in the OFF state (closed / open), the low-side drive side of the contactor is short-circuited to the power supply (LSDSCP).

[0060] Misjudgments include the following situations:

[0061] - When the contactor is in the OFF state (closed / open), the high-side drive side of the contactor is open (HSD OL);

[0062] - When the contactor is in the OFF state (closed / open), the low-side drive side of the contactor is open (LSD OL).

[0063] Table 1 below summarizes the missed and false alarms. The highlighted "Yes" indicates a fault state that can be detected using only the high-side control feedback signal or the high-low-side control feedback signal, while "Pending" indicates a fault state that cannot be detected using only the control feedback signal.

[0064]

[0065] Table 1. Possible Errors in Contactor Diagnosis

[0066] As can be seen from the table, "pending" indicates missed faults, while "misjudgment" indicates the inability to distinguish between two or more fault states, leading to incorrect fault state identification. For example, when the contactor is in the OFF state (closed / open), both OL (open circuit) and SCP (short circuit to power supply) on the high-side drive (HSD) side will be detected, but HSD OL is easily misjudged as HSD SCP. Similarly, when the contactor is in the OFF state (closed / open), LSD OL on the low-side drive (LSD) side can also be misjudged as LSD SCG.

[0067] According to embodiments of this disclosure, HSD unit 110 and LSD units 120 and 130 can be selected from chips with basic electrical diagnostic capabilities. These chips have built-in fault (status) registers and diagnostic (control) registers. The MCU writes (controls) the diagnostic control register by sending SPI commands to perform diagnostics. Then, the ASIC chips of HSD units 110 and LSD units 120 and 130 store the diagnostic results in the fault registers. The MCU reads the fault registers by sending SPI commands to obtain relevant fault information. For example, unit 110 has fault register 117 and diagnostic register 118, unit 120 has fault register 127 and diagnostic register 128, and unit 130 has fault register 137 and diagnostic register 138. At the MCU control end, different fault failure scenarios of the contactor can be analyzed, and the fault conditions of the high-side drive side and low-side drive side can be summarized. Based on the permutation and combination of the basic diagnostic capabilities of the high-side drive channel of the HSD unit and the low-side drive channel of the LSD unit, necessary information is provided for the diagnosis of the entire contactor. The fault register and diagnostic register record the diagnostic channel index values ​​that the chip can read to indicate the diagnostic status. Specifically, the fault register provides diagnostic fault bit data, and the diagnostic register provides diagnostic valid bit data. Combining the fault bit data and the diagnostic valid bit data yields fault bit data for contactor status prediction. The HSD unit and LSD unit can provide HSD fault bit data and LSD fault bit data, respectively.

[0068] According to embodiments of this disclosure, the diagnostic fault bit data in the diagnostic channel index value of the high-side drive HSD side channel is configured with corresponding bits for fault types SCP, SCG, and OL, and the diagnostic valid bit data is also configured with corresponding bits for fault types SCP, SCG, and OL. A logical AND operation is performed on the corresponding bits of the diagnostic fault bit data and the diagnostic valid bit data to obtain the final fault bit data, where a value of 1 indicates the occurrence or existence of the corresponding fault type, and a value of 0 indicates no corresponding fault type. The diagnostic channel index value, diagnostic fault bit data, diagnostic valid bit data, and the final fault bit data of the low-side drive LSD channel use a similar configuration and definition. Thus, the data definitions for the high-side drive fault bits on the HSD side and the low-side drive fault bits on the LSD side are as follows: SCP corresponds to a value of 001, SCG corresponds to a value of 010, OL corresponds to a value of 100, and normal (no fault) corresponds to a value of 000.

[0069] The chips of the HSD unit and LSD unit can also provide high-side state interface functions and low-side state interface functions, respectively. These functions are read through the software interface to provide the contactor command status represented by the interface status value or interface status bit of the corresponding drive-side channel contactor (as mentioned above, including "ON" for opening or closing, which can be represented by the value 1, and "OFF" for closing or opening, which can be represented by the value 0).

[0070] In the design, considering the risk of misjudgment, the analog signal retrieval achieved by the control feedback signals configured in the high-side drive side channel and the low-side drive side channel can be combined to further monitor the voltage output of the high-side drive side channel and the loop current of the low-side drive side channel in the drive circuit loop, based on the contactor state prediction of the chip itself, thereby enhancing and optimizing the diagnostic capability.

[0071] In this way, for each drive-side channel in the high- and low-side drive control, the analog signal retrieval of the control feedback signal, the contactor command status indicated by the interface status value or interface status bit, and the fault bit data can be used to summarize, integrate, and fuse the diagnostic results of the high-side and low-side drive-side channels. This allows for the design of accurate and reasonable diagnostic strategies to perform relevant independent diagnoses of actual scenarios and eliminate erroneous results caused by diagnostic limitations. This achieves a more accurate and comprehensive joint diagnostic strategy, improving diagnostic capabilities and obtaining better diagnostic results.

[0072] Figure 4 The diagram details various diagnosable fault states that may occur in the high-side drive side channel and low-side drive side channel of a contactor employing combined high-side and low-side drive control. In the diagram, the main positive contactor HV+ is used as an example; the situations for the main negative contactor HV-, fast-charging positive contactor DC+, and fast-charging negative contactor DC- are similar.

[0073] Based on the short-circuit and open-circuit conditions of the circuit, fault states can be classified into short circuit to power supply (SCP), short circuit to ground (SCG), and open circuit (OL). Combining the two channels of the contactor's high-side drive side and low-side drive side, the fault states can be further subdivided into HSD short circuit to power supply (HSD SCP), HSD short circuit to ground (HSD SCG), HSD open circuit (HSD OL), LSD short circuit to power supply (LSD SCP), LSD short circuit to ground (LSD SCG), and LSD open circuit (LSD OL), as shown below. Figure 4 As shown in 201, 202, 203, 204, 205 and 206.

[0074] For vehicle drive systems, the vehicle's drive state includes running and stationary states. In the running state, the MCU outputs an "ON" control command to open or close the contactor, causing it to engage and applying high voltage to the corresponding drive side. In the stationary state, the MCU outputs an "OFF" control command to close or de-energize the contactor, causing it to disengage and applying low voltage to the corresponding drive side. These six electrical fault and failure scenarios, combined with the vehicle's drive state, potentially result in a total of 12 fault failure scenarios. Each contactor terminal presents these undiagnosed fault failure scenarios.

[0075] It should be noted that when the vehicle is stationary (HSD side OFF or LSD side OFF), the drive unit chip will output a weak current of 100uA to detect any abnormalities in the entire circuit loop. For the diagnosis of the HSD and LSD sides of a single drive, there are limitations on the types of electrical diagnostics available when the vehicle is stationary (i.e., without switching the ON / OFF state of the drive side).

[0076] According to embodiments of this disclosure, the contactor diagnostic strategy needs to meet the following design objectives:

[0077] The high-side drive (HSD) side supports short-to-ground circuit (HSD SCG) detection in the command state of being on or off;

[0078] The high-side drive (HSD) side supports power supply short circuit (HSD SCP) detection in the command state of being off or disconnected;

[0079] The high-side drive (HSD) side supports open-circuit (HSD OL) detection in the command state of being off or disconnected ("OFF").

[0080] The low-side drive (LSD) side supports detection of power supply short circuit (LSD SCP) in the command state of being turned on or off;

[0081] The low-side drive (LSD) side supports short-to-ground detection (LSD SCG) in the command state of being turned off or on.

[0082] The low-side driver (LSD) supports open-circuit (LSD OL) detection in the "OFF" command state.

[0083] According to embodiments of this disclosure, a special configuration can be made in the chip driver to generate short pulses from the OFF command state to the ON command state (OFF to ON) or from the ON command state to the OFF command state (ON to OFF), thereby fully utilizing the diagnostic capabilities of the HSD and LSD sides for SCP, SCG, and OL under different command states. Under normal circumstances, this function is not enabled because generating such pulses in contactor control scenarios could potentially cause the contactor to unexpectedly disconnect.

[0084] The following section details the detection criteria for the six fault states in the contactor diagnostic strategy.

[0085] 1. HSD SCP, high-side drive side short circuit to power supply

[0086] When HSD = 0 (OFF command state), the contactor is in the OFF command state with the high-side drive side short-circuited to the power supply. The simulated high-side control feedback signal voltage is a high level of 9-16V (the normal high-side control feedback signal voltage is a low level of 2.5-3V). The value of the high-side state interface function of the HSD unit chip is OFF. At this time, the fault bit of the high-side drive is valid, and it is judged as HSD SCP. This method of directly determining the fault state type based on at least one of the contactor command state / state interface function value, fault bit data, and / or control feedback signal is called static judgment.

[0087] It should be noted that the above-mentioned 9-16V high level and 2.5-3V low level are only examples. The threshold level can be set according to the rated level or predetermined level suitable for the type of HSD unit and LSD unit selected and the type of contactor controlled, so as to distinguish between high level and low level based on the comparison result of the sampled signal voltage with the threshold level or threshold level range.

[0088] When HSD=1 (ON command state), the contactor is in the ON command state with a short circuit to the power supply on the high-side drive side. The simulated high-side control feedback signal voltage is a high level of 9-16V (the normal high-side control feedback signal voltage is also a high level of 9-16V). The value of the high-side state interface function of the HSD unit chip is ON. At this time, the combination of the high-side control feedback signal and the high-side state interface function value, as well as the fault bit of the high-side drive, cannot be diagnosed. Therefore, it is necessary to further perform HSD SCP diagnosis (HSD=0) during the subsequent contactor OFF command state to determine the short circuit to the power supply on the high-side drive side, and then determine the fault state when HSD=1 as HSD SCP. Performing HSD SCP diagnosis during the subsequent contactor OFF command state can be achieved by sending an OFF to ON command pulse to the contactor or waiting for the contactor to change from the OFF command state to the ON command state during the power-on or power-off phase. This judgment method is called command judgment. Similar diagnostic methods can be used for other fault states.

[0089] 2. HSD OL, high-side drive side open circuit

[0090] When HSD=0 (OFF command state), the high-side drive side of the contactor is open in the OFF command state. The simulated high-side control feedback signal voltage is a low level of 2.5-3V (the normal high-side control feedback signal voltage is also a low level of 2.5-3V). The value of the high-side state interface function of the HSD unit chip is OFF. At this time, the combination of the high-side control feedback signal and the high-side state interface function value, as well as the fault bit of the high-side drive, cannot be diagnosed. It is necessary to further determine whether there is a normal sampling current in the low-side control feedback signal of the low-side drive LSD side channel of the contactor after the contactor's ON command is executed (i.e., after the contactor has been opened). If the sampling current is zero (current value <0.1A, i.e., no current flows), it indicates that there is an open circuit on the HSD side, and the fault state command when HSD=0 is judged as HSD OL. If the sampling current is the rated load current (e.g., current value = 1A), there is no open circuit fault.

[0091] It should be noted that the above-mentioned current values ​​of <0.1A (no current) and 1A (load rated current) are merely examples. The distinction between no current and load rated current can be made by comparing the sampled signal current with the load rated current or current range, depending on the type of HSD and LSD units selected, the type of contactor being controlled, the suitable load rated current, and the current detection tolerance. The overcurrent value (2A) described below is also an example.

[0092] When HSD=1 (ON command state), the high-side drive side of the contactor is open in the ON command state. The simulated high-side control feedback signal voltage is a high level of 9-16V (the normal high-side control feedback signal voltage is also a high level of 9-16V). The value of the high-side state interface function of the HSD unit chip is ON. At this time, the combination of the high-side control feedback signal and the high-side state interface function value, as well as the fault bit of the high-side drive, cannot be diagnosed. Therefore, it is necessary to further determine whether there is a normal sampling current in the low-side control feedback signal of the low-side drive LSD side channel of the contactor after the contactor's ON command is executed (i.e., after the contactor has been opened). If the sampling current is zero (current value <0.1A, i.e., no current flows), it indicates that there is an open circuit on the HSD side, and the fault state command when HSD=1 is then judged as HSD OL. If the sampling current is the rated load current (e.g., current value = 1A), there is no open circuit fault.

[0093] 3. HSD SCG, short circuit to ground on the high-side drive side.

[0094] When HSD=0 (OFF command state), the contactor is short-circuited to ground on the high-side drive side in the OFF command state. The simulated high-side control feedback signal voltage is 0V (GND, while the normal high-side control feedback signal voltage is a low level of 2.5-3V). The value of the high-side state interface function of the HSD unit chip is OFF. At this time, the fault bit of the high-side drive is invalid. It can be statically judged as HSD SCG by the combination of the high-side control feedback signal and the high-side state interface function value.

[0095] When HSD=1 (ON command state), the contactor is short-circuited to ground on the high-side drive side in the ON command state. The simulated high-side control feedback signal voltage is 0V (GND, while the normal high-side control feedback signal voltage is a high level of 9-16V). The value of the high-side state interface function of the HSD unit chip is ON. At this time, the fault bit of the high-side drive is valid, and it can be statically judged as HSD SCG.

[0096] 4. LSD SCP, low-side drive side short circuit to power supply

[0097] When LSD=0 (OFF command state), the contactor is in the OFF command state with a short circuit to the power supply on the low-side drive side. The simulated low-side control feedback signal current is <0.1A (no current flows; the normal low-side control feedback signal current is also <0.1A). The value of the low-side state interface function of the LSD unit chip is OFF. At this time, the combination of the low-side control feedback signal and the low-side state interface function value, as well as the fault bit of the low-side drive, cannot be diagnosed. Therefore, it is necessary to further determine the low-side LSD SCP after the subsequent ON command (LSD=1) of the contactor is executed (i.e., after the contactor has completed opening), and determine the fault state command when LSD=0 as LSD SCP.

[0098] When LSD=1 (ON command), the contactor is in the ON command state and the low-side drive side is short-circuited to the power supply. The simulated low-side control feedback signal current is >2A (instantaneous value, which may not be readable, while the normal low-side control feedback signal current is <1A). The value of the low-side state interface function of the LSD unit chip is ON, and the fault bit of the low-side drive is valid. It can be statically judged as LSDSCP.

[0099] 5. LSD OL, low-side driver side open circuit

[0100] When LSD=0 (OFF command state), the contactor's low-side drive side is open in the OFF command state. The simulated low-side control feedback signal current is <0.1A (no current flows; the normal low-side control feedback signal current is also <0.1A). The low-side state interface function of the LSD unit chip is OFF. At this time, the combination of the low-side control feedback signal and the low-side state interface function value, as well as the fault bit of the low-side drive, cannot be diagnosed. Therefore, it is necessary to further determine whether there is a normal sampling current in the low-side control feedback signal of the LSD side channel of the contactor's low-side drive after the contactor ON command (LSD=1) has been executed (i.e., after the contactor has been opened). If the sampling current is zero (current value <0.1A, i.e., no current flows), it indicates that there is an open circuit on the LSD side, and the fault state command when LSD=0 is judged as LSD OL. If the sampling current is the rated load current (e.g., current value = 1A), there is no open circuit fault.

[0101] When LSD=1 (ON command state), the contactor's low-side drive side is open in the ON command state. The simulated low-side control feedback signal current is <0.1A (no current flows; the normal low-side control feedback signal current should be less than the rated load current of 1A). The low-side state interface function of the LSD unit chip is OFF. At this time, the combination of the low-side control feedback signal and the low-side state interface function value, as well as the fault bit of the low-side drive, cannot be diagnosed. Therefore, it is necessary to further determine whether there is a normal sampling current in the low-side control feedback signal of the LSD side channel of the contactor's low-side drive after the contactor ON command (LSD=1) has been executed (i.e., after the contactor has been opened). If the sampling current is zero (current value <0.1A, i.e., no current flows), it indicates that there is an open circuit on the LSD side, and the fault state command when LSD=1 is judged as LSD OL. If the sampling current is the rated load current (e.g., current value = 1A), there is no open circuit fault.

[0102] 6. LSD SCG, low-side drive side short circuit to ground

[0103] When LSD=0 (OFF command state), the contactor is short-circuited to ground on the low-side drive side in the OFF command state. The simulated low-side control feedback signal current is <0.1A (no current flows, and the normal low-side control feedback signal current is also <0.1A). The low-side state interface function of the LSD unit chip is OFF, and the fault bit of the low-side drive is valid. It can be statically judged as LSD SCG.

[0104] When LSD=1 (ON command state), the contactor is short-circuited to ground on the low-side drive side in the ON command state. The simulated low-side control feedback signal current is <1A (the normal low-side control feedback signal current is also <1A). The low-side state interface function of the LSD unit chip is ON. At this time, the combination of the low-side control feedback signal and the low-side state interface function value, as well as the fault bit of the low-side drive, cannot be diagnosed. Therefore, it is necessary to further determine the low-side drive side short-circuit LSD SCG after the contactor's OFF command is executed (i.e., after the contactor has completed closing), and determine the fault state command when LSD=1 as LSD SCG.

[0105] The corresponding data for the above-mentioned fault states are listed in Table 2 below.

[0106]

[0107] Table 2 shows the detection data information corresponding to the fault status.

[0108] Based on the detection standards of the diagnostic strategies corresponding to the above fault state types, different diagnostic strategies can be implemented in different vehicle scenarios, and corresponding control logic can be formulated. The 14 relevant vehicle scenarios are as follows:

[0109] 1. Under normal conditions, there are no electrical faults. At this time, the vehicle's command status is contactor OFF, the voltage of the simulated high-side control feedback signal is 2.5-3V, and the current of the low-side control feedback signal is <0.1A, which is consistent with the normal control feedback signal.

[0110] 2. In a normal scenario, there are no electrical faults. At this time, the vehicle's command status is contactor ON, the voltage of the simulated high-side control feedback signal is 9-16V, and the current of the low-side control feedback signal is about 1A (i.e., the rated load current), which is consistent with the normal control feedback signal.

[0111] 3. When the contactor is not controlled at the vehicle end, the high-side drive side of the contactor is short-circuited to the power supply. The vehicle's command state is contactor OFF, and the cause of the fault failure state is HSD SCP. At this time, the simulated high-side control feedback signal voltage is 9-16V (normal signal voltage is 2.5-3V), and the low-side control feedback signal current is <0.1A (normal signal current is <0.1A). Further differentiation from vehicle scenario 9 is needed.

[0112] Read the diagnostic channel index values ​​of the HSD and LSD unit chips and determine the final fault bit data. If the HSD side fault bit = 001 and the LSD side fault bit = 000, a contactor ON command needs to be sent or further detection needs to be performed during the power-on phase. After the command is sent, if the HSD side fault bit = 000 and the LSD side fault bit = 000, and the low-side control feedback signal current is the rated load current, it can be determined that the high-side drive of the contactor is short-circuited to the power supply.

[0113] 4. When the vehicle-side control contactor is open / closed (HSD=1 and LSD=1), the vehicle sends an ON command to the contactor. The low-side drive side executes the LSD=1 command normally, but the high-side drive side of the contactor is short-circuited to the power supply, so the HSD=1 command cannot be executed normally. The cause of the fault failure is HSD SCP. At this time, the simulated high-side control feedback signal voltage is 9-16V (normal signal voltage is 9-16V), and the low-side control feedback signal current is about 1A (normal signal current is about 1A of the load's rated current). Further differentiation from vehicle scenarios 2, 6, 12, and 14 is needed.

[0114] Since the contactor is operating normally (normal operating current) at this time, it is necessary to wait for the contactor to enter the OFF command state to identify the fault failure state of the high-side drive side short circuit to the power supply. The corresponding judgment strategy is as follows: if the contactor is operating normally and there are no valid HSD side and LSD side fault bits when it is in the ON command state, but the fault bit data collected from the register when the contactor is in the OFF command state is HSD side fault bit = 001 and LSD side fault bit = 000, then it can be determined that the contactor has a high-side drive side short circuit to the power supply.

[0115] 5. When the contactor is not controlled at the vehicle end, the high-side drive side of the contactor is open, the vehicle's command state is contactor OFF, and the cause of the fault failure state is HSD OL. At this time, the analog-sampled high-side control feedback signal voltage is 2.5-3V (normal signal voltage is 2.5-3V), and the low-side control feedback signal current is <0.1A (normal signal current is <0.1A). Further differentiation from vehicle scenario 11 is needed.

[0116] If, when the contactor is in the OFF command state, the fault bit data read from the register is HSD side fault bit = 100 and LSD side fault bit = 100, and when the contactor is sent to the ON command, the fault bit data read from the register is HSD side fault bit = 000 and LSD side fault bit = 000, and at the same time, no normal current is collected in the drive circuit (current < 0.1A), then it can be determined that there is an open circuit fault in the high and low side drive circuits.

[0117] It should be noted that when either the high-side drive side or the low-side drive side is open-circuited, the current diagnostic strategy may not be able to accurately identify the location of the open circuit. This is because the contactor load is a closed electromagnetic coil for both high-side and low-side control. Any open-circuit fault occurring anywhere in this drive circuit will cause both the high-side and low-side drive sides to report open-circuit fault data when the contactor is in the OFF command state. When an open-circuit fault occurs, external testing using devices such as a multimeter can be used to accurately locate the break point.

[0118] 6. When the vehicle-side control contactor is open / closed (HSD=1 and LSD=1), the vehicle sends a command to turn the contactor ON. The low-side drive side executes the LSD=1 command normally, but the high-side drive side of the contactor is open, so the HSD=1 command cannot be executed normally. The cause of the fault failure state is HSD OL. At this time, the analog high-side control feedback signal voltage is 9-16V (the normal signal voltage is 9-16V), and the low-side control feedback signal current is <0.1A (the normal signal current is about 1A of the load's rated current). It needs to be further distinguished from vehicle scenarios 2, 4, 12, and 14.

[0119] Similar to scenario 5 for the whole vehicle, if the fault bit data read from the register is 100 for both the HSD and LSD sides when the contactor is in the OFF command state, then when the contactor is sent to ON, the fault bit data read from the register must be 000 for both the HSD and LSD sides. Simultaneously, if no normal current is detected in the drive circuit (current value < 0.1A), then an open circuit fault can be determined in the drive circuit on either the high or low side. Similarly, if either the high or low side drive is open, the current diagnostic strategy may not be able to accurately identify the location of the open circuit break.

[0120] 7. When the contactor is not controlled at the vehicle end, the high-side drive side of the contactor is short-circuited to ground. The vehicle's command state is contactor OFF, and the cause of the fault failure state is HSD SCG. At this time, the analog high-side control feedback signal voltage is 0V (GND, normal signal voltage is 2.5-3V), and the low-side control feedback signal current is <0.1A (normal signal current is around <0.1A). This needs to be further distinguished from vehicle scenario 13.

[0121] If the contactor's command status is OFF, read the corresponding registers of the HSD and LSD unit chips. If the HSD side fault bit = 000 and the LSD side fault bit = 010, it is necessary to read the voltage value of the high-side control feedback signal. If the signal voltage is 0V, it can be determined that the high-side drive side of the contactor is short-circuited to ground.

[0122] 8. When the vehicle-side control contactor is open / closed (HSD=1 and LSD=1), the vehicle's command status is contactor ON. The low-side drive side executes the LSD=1 command normally, but the high-side drive side of the contactor is short-circuited to ground, so the HSD=1 command cannot be executed normally. The cause of the fault failure is HSD SCG. At this time, the high-side control feedback signal voltage of the simulated feedback is 0V (GND, the normal signal voltage is 9-16V), and the low-side control feedback signal current is <0.1A (maintaining voltage to ground after overcurrent turn-off, while the normal signal current is about 1A of the load's rated current).

[0123] If the contactor's command state is ON, read the corresponding registers of the HSD and LSD unit chips. If the HSD side fault bit = 010 and the LSD side fault bit = 100, and the high-side control feedback signal voltage is 0V, then it can be determined that the high-side drive side of the contactor is short-circuited to ground.

[0124] 9. When the contactor is not controlled by the vehicle, the low-side drive side of the contactor is short-circuited to the power supply. The vehicle's command state is contactor OFF, and the cause of the fault failure state is LSD SCP. At this time, the high-side control feedback signal voltage is 9-16V (normal signal voltage is 2.5-3V), and the low-side control feedback signal current is <0.1A (normal signal current is <0.1A). This needs to be further distinguished from vehicle scenario 3.

[0125] If the current command state of the contactor is OFF, the corresponding registers of the HSD and LSD unit chips are read (HSD side fault bit = 001 and LSD side fault bit = 000). At this time, the location of the power supply short circuit cannot be directly determined. It is necessary to wait for the next contactor to execute the ON command and use the diagnostic strategy of vehicle scenario 10 to determine the short circuit to ground on the low-side drive side of the contactor.

[0126] 10. When the vehicle requests the contactor to open / close (HSD=1 and LSD=1), the vehicle's command status is contactor ON. The high-side drive side executes the HSD=1 command normally, but the low-side drive side of the contactor is short-circuited to the power supply, so the LSD=1 command cannot be executed normally. The cause of the fault failure is LSD SCP. At this time, the simulated high-side control feedback signal voltage is 9-16V (normal signal voltage is 9-16V), and the low-side control feedback signal current is >2A (instantaneous, possibly unreadable; normal signal current is approximately 1A, the rated load current).

[0127] If the contactor's command state is ON, read the corresponding registers of the HSD and LSD unit chips. If the HSD side fault bit = 000 and the LSD side fault bit = 001, it can be determined that the low-side drive side of the contactor is short-circuited to ground.

[0128] 11. When the contactor is not controlled at the vehicle end, the low-side drive side of the contactor is open. The vehicle's command state is contactor OFF, and the fault failure state is caused by LSD OL. At this time, the high-side control feedback signal voltage sampled from the simulation is 2.5-3V (normal signal voltage is 2.5-3V), and the low-side control feedback signal current is <0.1A (normal signal current is <0.1A). This needs to be further distinguished from vehicle scenario 5.

[0129] Similar to scenario 5 for the whole vehicle, if the fault bit data obtained from reading the register when the contactor's command state is OFF is HSD side fault bit = 100 and LSD side fault bit = 100, then when the contactor's ON command is sent, if the fault bit data obtained from reading the register is HSD side fault bit = 000 and LSD side fault bit = 000, and no normal current is detected in the drive circuit (current value < 0.1A), then it can be determined that an open circuit fault has occurred in the high and low side drive circuits. Similarly, if the high side drive side or the low side drive side is open, the current diagnostic strategy may not be able to accurately identify the location of the open circuit break.

[0130] 12. When the vehicle-side control contactor is open / closed (HSD=1 and LSD=1), the vehicle's command status is contactor ON. The high-side drive side executes the HSD=1 command normally, but the low-side drive side of the contactor is open, so the LSD=1 command cannot be executed normally. The cause of the fault failure is LSD OL. At this time, the simulated high-side control feedback signal voltage is 9-16V (normal signal voltage is 9-16V), and the low-side control feedback signal current is <0.1A (normal signal current is about 1A of the load's rated current). Further differentiation from vehicle scenarios 2, 4, 6, and 14 is needed.

[0131] Similar to scenario 5 for the whole vehicle, if the fault bit data obtained from reading the register when the contactor's command state is OFF is HSD side fault bit = 100 and LSD side fault bit = 100, then when the contactor's ON command is sent, if the fault bit data obtained from reading the register is HSD side fault bit = 000 and LSD side fault bit = 000, and no normal current is detected in the drive circuit (current value < 0.1A), then it can be determined that an open circuit fault has occurred in the high and low side drive circuits. Similarly, if the high side drive side or the low side drive side is open, the current diagnostic strategy may not be able to accurately identify the location of the open circuit break.

[0132] 13. When the contactor is not controlled at the vehicle end, the low-side drive side of the contactor is short-circuited to ground. The vehicle's command state is contactor OFF, and the cause of the fault failure state is LSD SCG. At this time, the high-side control feedback signal voltage is 2.5-3V (normal signal voltage is 2.5-3V), and the low-side control feedback signal current is <0.1A (normal signal current <0.1A). This needs to be further distinguished from vehicle scenario 7.

[0133] If the current contactor command status is OFF, read the corresponding registers of the HSD and LSD unit chips. If the obtained HSD side fault bit = 000 and LSD side fault bit = 010, and the high-side control feedback signal voltage is read as 2.5-3V, then it can be determined that the low-side drive side of the contactor is short-circuited to ground.

[0134] 14. When the vehicle-side control contactor is open / closed (HSD=1 and LSD=1), the vehicle's command status is contactor ON. The high-side drive side executes the HSD=1 command normally, but the low-side drive side of the contactor is short-circuited to ground, so the LSD=1 command cannot be executed normally. The cause of the fault failure is LSD SCG. At this time, the high-side control feedback signal voltage is 9-16V (normal signal voltage is 9-16V), and the low-side control feedback signal current is about 1A (normal signal current is about 1A of the load's rated current). This needs to be further distinguished from vehicle scenarios 2, 4, 6, and 12.

[0135] If the contactor's command status is contactor ON, the fault bit data obtained from the corresponding registers of the HSD and LSD unit chips cannot be directly used for judgment because the contactor is in normal working condition at this time. In this case, it is necessary to wait for the contactor to execute the OFF command and use a diagnostic strategy similar to that in vehicle scenario 13 for joint judgment.

[0136] The aforementioned diagnostic strategies enable joint diagnosis and information fusion of both high- and low-side drive control designs, providing more comprehensive and effective monitoring for dual-side drive contactors. Based on different contactor failure scenarios, control failures on both high- and low-side drive channels can be summarized, allowing for more precise differentiation and identification of diagnostic scenarios, and the design of broader diagnostic logic strategies and algorithms. Through related combined control, ideal functional safety levels (e.g., ASIL B) can be achieved. Applying this diagnostic strategy at the vehicle level prevents invalid, missed, and misdiagnostic diagnoses at the contactor drive control end. Screening for erroneous diagnostic scenarios facilitates problem identification and troubleshooting during development and after-sales phases, enabling the development of appropriate solutions.

[0137] Those skilled in the art will understand that vehicle energy storage systems, battery charging (fast and normal), and on-board accessories and other equipment and systems can also be controlled by high-side and low-side driven bilateral control contactors, and therefore can also be designed using the diagnostic strategies proposed in this disclosure.

[0138] Figure 5 A schematic flowchart of a method for diagnosing contactors is shown.

[0139] A method for diagnosing a contactor according to an embodiment of the present disclosure may include step S510 of acquiring a control feedback signal, a contactor command status, and fault bit data of the contactor; step S520 of determining whether the contactor is in a fault state based on the control feedback signal and the contactor command status; and step S530 of further determining at least one of the type and location of the fault state based on the acquired control feedback signal, the contactor command status, and the fault bit data if the contactor is determined to be in a fault state.

[0140] The control feedback signals may include a high-side control feedback signal indicating the voltage of the high-side drive control signal and a low-side control feedback signal indicating the current of the low-side drive control signal. The contactor command status includes an open state for controlling contactor closure and a closed state for controlling contactor disengagement. Fault bit data indicates whether the contactor is in a fault state and / or the position of the fault state, including a high-side drive fault bit and a low-side drive fault bit.

[0141] Furthermore, different diagnostic criteria and strategies can be adopted based on the specific fault type. For example, if the contactor command state is open, the high-side control feedback signal is high, and the low-side control feedback signal is the rated load current, the contactor is determined to be in a normal state; similarly, if the contactor command state is closed, the high-side control feedback signal is low, and the low-side control feedback signal is zero current, the contactor is determined to be in a normal state. In other cases, the contactor is determined to be in a fault state.

[0142] Regarding the fault status:

[0143] If the contactor is in a closed command state, the high-side control feedback signal is high, and the high-side drive fault bit indicates a fault, then the high-side drive side of the contactor is determined to be short-circuited to the power supply. If the contactor is in an open command state, the high-side control feedback signal is high, and a short circuit to the power supply is determined to occur during a subsequent closed command state, then the high-side drive side of the contactor is determined to be short-circuited to the power supply.

[0144] If the contactor is in the open command state, the high-side control feedback signal is high, and the low-side control feedback signal has zero current after the contactor has been opened, the high-side drive side of the contactor is determined to be open. If the contactor is in the closed command state, the high-side control feedback signal is low, and the low-side control feedback signal has zero current after the contactor has been opened, the high-side drive side of the contactor is determined to be open.

[0145] If the contactor command state is open and the high-side control feedback signal is at zero level, it is determined that the high-side drive side of the contactor is short-circuited to ground; if the contactor command state is closed and the high-side control feedback signal is at zero level, it is determined that the high-side drive side of the contactor is short-circuited to ground.

[0146] If the contactor command state is open, the low-side control feedback signal exceeds the rated load current, and the low-side drive fault position indicates a fault, it is determined that the low-side drive side of the contactor is short-circuited to the power supply. If the contactor command state is closed, the low-side control feedback signal is zero current, and it is determined that the low-side drive side of the contactor is short-circuited to the power supply after the contactor has been opened, it is determined that the low-side drive side of the contactor is short-circuited to the power supply.

[0147] If the contactor command state is open, the low-side control feedback signal has zero current, and the low-side control feedback signal has zero current after the contactor has been opened, then the low-side drive side of the contactor is determined to be open; if the contactor command state is closed, the low-side control feedback signal has zero current, and the low-side control feedback signal has zero current after the contactor has been opened, then the low-side drive side of the contactor is determined to be open.

[0148] If the contactor is in the closed command state, the low-side control feedback signal is at zero current, and the low-side drive fault position indicates a fault, then the low-side drive side of the contactor is determined to be short-circuited to ground. If the contactor is in the open command state, the low-side control feedback signal is at the rated load current, and a short circuit to ground is determined to be short-circuited to ground on the low-side drive side of the contactor after the contactor has been closed, then the low-side drive side of the contactor is determined to be short-circuited to ground.

[0149] Other control strategy details are combined with the above. Figures 1 to 4 The introductory section will not be elaborated upon further.

[0150] Figure 6A schematic block diagram of a device for diagnosing a contactor is shown. The device 600 includes a high-side drive unit 620 and a low-side drive unit 630, configured to provide high-side drive control signals and low-side drive control signals for controlling the contactor, respectively, and to provide fault position data of the contactor; and a diagnostic unit 610 configured to acquire the contactor's control feedback signal, contactor command status, and contactor fault position data; determine whether the contactor is in a fault state based on the control feedback signal and contactor command status; and, if the contactor is in a fault state, determine at least one of the type and location of the fault state based on the control feedback signal, contactor command status, and fault position data.

[0151] The diagnostic unit 610 can also be configured to further implement, such as Figure 5 More specific step details of any of steps S510 to S530 shown.

[0152] It should be noted that although several modules or units for diagnosing contactors have been mentioned in the detailed description above, this division is not mandatory. In fact, according to embodiments of this disclosure, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units. Components shown as modules or units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this disclosure according to actual needs. Those skilled in the art can understand and implement this without inventive effort.

[0153] In exemplary embodiments of this disclosure, a computer-readable storage medium is also provided, having stored thereon a computer program including executable instructions that, when executed by, for example, a processor, can implement the steps of the method for diagnosing a contactor described in any of the above embodiments. In some possible implementations, various aspects of this disclosure can also be implemented as a program product including program code that, when run on a terminal device, causes the terminal device to perform the steps described in the various exemplary embodiments of this disclosure for diagnosing a contactor.

[0154] The program product for implementing the above-described method according to embodiments of this disclosure may employ a portable compact disc read-only memory (CD-ROM) and include program code, and may run on a terminal device, such as a personal computer. However, the program product of this disclosure is not limited thereto. In this document, a readable storage medium may be any tangible medium that contains or stores a program that may be used by or in conjunction with an instruction execution system, apparatus, or device.

[0155] The program product may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0156] The computer-readable storage medium may include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. The readable storage medium may also be any readable medium other than a readable storage medium, capable of transmitting, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the readable storage medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.

[0157] Program code for performing the operations of this disclosure can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0158] In exemplary embodiments of this disclosure, an electronic device is also provided, which may include a processor and a memory for storing executable instructions of the processor. The processor is configured to perform the steps of the method for diagnosing a contactor in any of the above embodiments by executing the executable instructions.

[0159] Those skilled in the art will understand that various aspects of this disclosure can be implemented as a system, method, or program product. Therefore, various aspects of this disclosure can be specifically implemented in the following forms: a completely hardware implementation, a completely software implementation (including firmware, microcode, etc.), or a combination of hardware and software aspects, collectively referred to herein as a "circuit," "module," or "system."

[0160] The following reference Figure 7 To describe an electronic device 700 according to such an embodiment of the present disclosure. Figure 7 The electronic device 700 shown is merely an example and should not be construed as limiting the functionality and scope of the embodiments of this disclosure.

[0161] like Figure 7 As shown, the electronic device 700 is presented in the form of a general-purpose computing device. The components of the electronic device 700 may include, but are not limited to: at least one processing unit 710, at least one storage unit 720, a bus 730 connecting different system components (including storage unit 720 and processing unit 710), a display unit 740, etc.

[0162] The storage unit stores program code that can be executed by the processing unit 710, causing the processing unit 710 to perform the steps described in the method for diagnosing a contactor according to various exemplary embodiments of this disclosure. For example, the processing unit 710 can perform actions such as... Figure 5 The steps are shown in the figure.

[0163] The storage unit 720 may include a readable medium in the form of a volatile storage unit, such as a random access memory unit (RAM) 7201 and / or a cache storage unit 7202, and may further include a read-only memory unit (ROM) 7203.

[0164] The storage unit 720 may also include a program / utility 7204 having a set (at least one) program module 7205, such program module 7205 including but not limited to: an operating system, one or more application programs, other program modules and program data, each or some combination of these examples may include an implementation of a network environment.

[0165] Bus 730 can represent one or more of several types of bus structures, including a memory cell bus or memory cell controller, a peripheral bus, a graphics acceleration port, a processing unit, or a local bus using any of the various bus structures.

[0166] Electronic device 700 can also communicate with one or more external devices 800 (e.g., keyboard, pointing device, Bluetooth device, etc.), and with one or more devices that enable a user to interact with electronic device 700, and / or with any device that enables electronic device 700 to communicate with one or more other computing devices (e.g., router, modem, etc.). This communication can be performed via input / output (I / O) interface 750. Furthermore, electronic device 700 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via network adapter 760. Network adapter 760 can communicate with other modules of electronic device 700 via bus 730. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with electronic device 700, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0167] From the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, or network device, etc.) to execute the method for diagnosing contactors according to the embodiments of this disclosure.

[0168] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

Claims

1. A method for diagnosing a contactor, the contactor being controlled by a high-side drive control signal from a high-side drive unit and a low-side drive control signal from a low-side drive unit, the method comprising: Acquire the control feedback signal, contactor command status, and fault position data of the contactor; Based on the control feedback signal and the contactor command status, determine whether the contactor is in a fault state; as well as When the contactor is in a fault state, based on the control feedback signal, the contactor command state, and the fault position data, at least one of the type and location of the fault state is determined.

2. The method according to claim 1, characterized in that, The types of fault states include: short circuit to power supply, short circuit to ground, and open circuit.

3. The method according to claim 2, characterized in that, The control feedback signal includes a high-side control feedback signal indicating the voltage of the high-side drive control signal and a low-side control feedback signal indicating the current of the low-side drive control signal. The contactor command status includes an open state for controlling the contactor to close and a closed state for controlling the contactor to open. The fault position data is used to indicate whether the contactor has a fault state and / or the location of the fault state. The fault position data includes a high-side drive fault position and a low-side drive fault position.

4. The method according to claim 3, characterized in that, Determining whether the contactor is in a fault state based on the control feedback signal and the contactor command status further includes: When the contactor command state is open, the high-side control feedback signal is high, and the low-side control feedback signal is the load rated current, the contactor is in normal condition. When the contactor command state is closed, the high-side control feedback signal is low, and the low-side control feedback signal has zero current, the contactor is in normal condition. In other cases, the contactor is in a faulty state.

5. The method according to claim 4, characterized in that, Determining at least one of the type and location of the fault state includes: If the contactor command state is closed, the high-side control feedback signal is high, and the high-side drive fault bit indicates a fault, it is determined that the high-side drive side of the contactor is short-circuited to the power supply. If the contactor is in an open command state, the high-side control feedback signal is high, and a short circuit to the power supply is determined on the high-side drive side of the contactor during a subsequent close command state, then the short circuit to the power supply on the high-side drive side of the contactor is determined.

6. The method according to claim 4, characterized in that, Determining at least one of the type and location of the fault state includes: When the contactor command state is open, the high-side control feedback signal is high, and the low-side control feedback signal has zero current after the contactor has been opened, it is determined that the high-side drive side of the contactor is open. If the contactor command state is closed, the high-side control feedback signal is low, and the low-side control feedback signal has zero current after the contactor has been turned on, then the high-side drive side of the contactor is determined to be open.

7. The method according to claim 4, characterized in that, Determining at least one of the type and location of the fault state includes: If the contactor command state is open and the high-side control feedback signal is at zero level, it is determined that the high-side drive side of the contactor is short-circuited to ground. If the contactor command state is closed and the high-side control feedback signal is at zero level, it is determined that the high-side drive side of the contactor is short-circuited to ground.

8. The method according to claim 4, characterized in that, Determining at least one of the type and location of the fault state includes: If the contactor command state is open, the low-side control feedback signal exceeds the rated load current, and the low-side drive fault position indicates a fault, it is determined that the low-side drive side of the contactor is short-circuited to the power supply. If the contactor command state is closed, the low-side control feedback signal is zero current, and it is determined that the low-side drive side of the contactor is short-circuited to the power supply after the contactor has been turned on, then the low-side drive side of the contactor is determined to be short-circuited to the power supply.

9. The method according to claim 4, characterized in that, Determining at least one of the type and location of the fault state includes: If the contactor command state is open, the low-side control feedback signal is zero current, and the low-side control feedback signal is zero current after the contactor has been opened, then the low-side drive side of the contactor is determined to be open. If the contactor command state is closed, the low-side control feedback signal has zero current, and the low-side control feedback signal has zero current after the contactor has been turned on, then the low-side drive side of the contactor is determined to be open.

10. The method according to claim 4, characterized in that, Determining at least one of the type and location of the fault state includes: If the contactor command state is closed, the low-side control feedback signal is zero current, and the low-side drive fault position indicates a fault, it is determined that the low-side drive side of the contactor is short-circuited to ground. If the contactor command state is open, the low-side control feedback signal is the load rated current, and a short circuit to ground is determined on the low-side drive side of the contactor after the contactor has been closed, then a short circuit to ground is determined on the low-side drive side of the contactor.

11. The method according to any one of claims 1 to 10, characterized in that, The contactor includes at least one of a main positive contactor, a main negative contactor, a fast-charging positive contactor, and a fast-charging negative contactor.

12. The method according to claim 11, characterized in that, The contactor is used in at least one of the vehicle's drive system, battery charging system, and braking system.

13. An apparatus for diagnosing a contactor, the contactor being controlled by a high-side drive control signal from a high-side drive unit and a low-side drive control signal from a low-side drive unit, the apparatus comprising: The high-side drive unit and the low-side drive unit are configured to provide high-side drive control signals and low-side drive control signals for controlling the contactor, respectively, and to provide fault position data of the contactor. The diagnostic unit is configured to acquire the control feedback signal of the contactor, the contactor command status, and the fault position data; Based on the control feedback signal and the contactor command status, determine whether the contactor is in a fault state; In the event that the contactor is in a fault state, at least one of the type and location of the fault state is determined based on the control feedback signal, the contactor command state, and the fault position data.

14. The apparatus according to claim 13, characterized in that, The microcontroller unit is further configured to implement the method according to any one of claims 2 to 12.

15. A computer-readable storage medium having a computer program stored thereon, the computer program including executable instructions that, when executed by a processor, implement the method according to any one of claims 1 to 12.

16. An electronic device, characterized in that, include: processor; as well as Memory for storing the executable instructions of the processor; The processor is configured to execute the executable instructions to implement the method according to any one of claims 1 to 12.

17. A computer program product comprising a computer program that, when executed by a processor, performs the method according to any one of claims 1 to 12.

18. A vehicle comprising the means for diagnosing a contactor as claimed in claim 13 or 14.

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