CN-121995202-A - Method and device for diagnosing a contactor

Abstract

The present disclosure presents methods and apparatus for diagnosing a contactor. The method includes obtaining control feedback signals for the contactor, contactor command status and fault bit data, determining whether the contactor is in a fault state, and determining at least one of a type and a position of the fault state if the contactor is in the fault state. The method can carry out joint diagnosis and information fusion aiming at the contactor driven and controlled by the high side and the low side, realize more comprehensive monitoring of the contactor and meet the ideal functional safety level.

Inventors

• YAN JIADONG

Assignees

• 纬湃科技投资(中国)有限公司

Dates

Publication Date

20260508

Application Date

20241107

Claims (18)

1. 1. 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, the method comprising: acquiring a control feedback signal of the contactor, and command state and fault bit data of the contactor; determining whether the contactor is in a fault state based on the control feedback signal and the contactor command state, and In the event that the contactor is in a fault state, based on the control feedback signal, the contactor command state and the fault bit data determine at least one of a type and a location of the fault state.
2. 2. The method of claim 1, wherein the types of fault conditions include short-to-power, short-to-ground, and open-circuit.
3. 3. The method of claim 2, wherein the step of determining the position of the substrate comprises, The control feedback signals include a high side control feedback signal indicating a voltage of the high side drive control signal and a low side control feedback signal indicating a current of the low side drive control signal; The contactor command status includes an open for controlling the contactor to close and a closed for controlling the contactor to open; the fault bit data is used for indicating whether the contactor has a fault state and/or the position of the fault state, and the fault bit data comprises a high-side driving fault bit and a low-side driving fault bit.
4. 4. The method of claim 3, wherein determining whether the contactor is in a fault state based on the control feedback signal and the contactor command state further comprises: when the contactor command state is on, the high-side control feedback signal is at a high level, and the low-side control feedback signal is at a load rated current, the contactor is in a normal state; When the contactor command state is closed, the high-side control feedback signal is at a low level, and the low-side control feedback signal is at zero current, the contactor is in a normal state; In other cases, the contactor is in a fault state.
5. 5. The method of claim 4, wherein determining at least one of a type and a location of the fault condition comprises: Determining that the high-side driving side of the contactor is short-circuited to power supply when the contactor command state is closed, the high-side control feedback signal is high, and the high-side driving fault bit indicates that a fault occurs; In the event that the contactor command state is on, the high side control feedback signal is high, and in the event that a high side drive side to power short of the contactor is determined during a subsequent contactor command state is off, the high side drive side to power short of the contactor is determined.
6. 6. The method of claim 4, wherein determining at least one of a type and a location of the fault condition comprises: Determining a high side drive side open circuit of the contactor if the contactor command state is on, the high side control feedback signal is high, and the low side control feedback signal is zero current after the contactor has been turned on; the high side drive side open circuit of the contactor is determined in the event that the contactor command state is off, the high side control feedback signal is low, and the low side control feedback signal is zero current after the contactor opening has been subsequently completed.
7. 7. The method of claim 4, wherein determining at least one of a type and a location of the fault condition comprises: Determining a high-side drive side-to-ground short of the contactor if the contactor command state is on and the high-side control feedback signal is at zero level; In the event that the contactor command state is off and the high side control feedback signal is at zero level, a high side drive side to ground short of the contactor is determined.
8. 8. The method of claim 4, wherein determining at least one of a type and a location of the fault condition comprises: determining that the low-side drive side of the contactor is shorted to power supply if the contactor command status is on, the low-side control feedback signal exceeds a load rated current, and the low-side drive fault bit indicates a fault; In the event that the contactor command state is off, the low side control feedback signal is zero current, and a low side drive side to power short circuit of the contactor is determined after the contactor opening has been subsequently completed.
9. 9. The method of claim 4, wherein determining at least one of a type and a location of the fault condition comprises: Determining that a low side drive side of the contactor is open 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 opening of the contactor has been completed; In the event that the contactor command state is off, the low side control feedback signal is zero current, and in the event that the low side control feedback signal is zero current after the opening of the contactor has been completed thereafter, a low side drive side open circuit of the contactor is determined.
10. 10. The method of claim 4, wherein determining at least one of a type and a location of the fault condition comprises: determining that the low-side drive side of the contactor is shorted to ground if the contactor command status is off, the low-side control feedback signal is zero current, and the low-side drive fault bit indicates a fault; In the event that the contactor command status is on, the low side control feedback signal is a load rated current, and a low side drive side to ground short of the contactor is determined after the closing of the contactor has been completed thereafter.
11. 11. The method of any one of claims 1 to 10, wherein the contactor comprises at least one of a main positive contactor, a main negative contactor, a fast positive contactor, and a fast negative contactor.
12. 12. The method of claim 11, wherein the contactor is used in at least one of a drive system, a battery charging system, and a braking system of a vehicle.
13. 13. An apparatus 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, comprising: A high side drive unit and a low side drive unit configured to provide a high side drive control signal and a low side drive control signal for controlling the contactor, respectively, and to provide fault bit data of the contactor; The contactor control system includes a contactor control unit configured to obtain a control feedback signal of the contactor, a contactor command state and the fault bit data, determine whether the contactor is in a fault state based on the control feedback signal and the contactor command state, and determine at least one of a type and a position of the fault state based on the control feedback signal and the fault bit data in case the contactor is in the fault state.
14. 14. The apparatus of claim 13, wherein the micro control unit is further configured to implement the method of any one of claims 2 to 12.
15. 15. A computer readable storage medium having stored thereon a computer program comprising executable instructions which, when executed by a processor, implement the method according to any of claims 1 to 12.
16. 16. An electronic device, comprising: processor, and A memory for storing executable instructions of the processor; wherein the processor is configured to execute the executable instructions to implement the method of any one of claims 1 to 12.
17. 17. A computer program product comprising a computer program which, when executed by a processor, implements the method according to any one of claims 1 to 12.
18. 18. A vehicle comprising a device for diagnosing a contactor according to claim 13 or 14.

Description

Method and device for diagnosing a contactor Technical Field The present 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 high-low side combinations. Background In a vehicle system such as an electric vehicle, a high voltage control system is used to control and adjust the state of a high voltage contactor that supplies and operates a vehicle high voltage bus. Conventional contactor control schemes are based on a single-sided control approach of the high-side drive (HIGH SIDE DRIVE, HSD), and the diagnostic strategy associated with the contactor is entirely dependent on the diagnostic capabilities of the high-side drive side. In general, this diagnostic method makes only a simple feedback diagnosis of the on and off state of the contactor, i.e. only the opening and closing of the contactor is determined. Along with the increasingly strict requirements of high-voltage control systems of automobiles on the design reliability and performance reliability of high-voltage contactors, a control mode for adjusting the states of the contactors through high-side driving and Low-side driving (Low SIDE DRIVE, LSD) double-side combined driving is derived. However, the synchronous control of the high side and the low side still uses the feedback signal of the high side and the low side as the main information source needed by the diagnosis, and the diagnosis of the control end of the contactor is not covered well. The contactor controlled by the single side at the high side driving side can only feed back the related control state from the whole vehicle end of the vehicle, so that the reliability is low, and misjudgment or missed judgment is easy to occur. For example, if a failure condition of a short circuit to the power supply of a contactor controlled by a high-side drive control signal cannot be accurately diagnosed, it may be difficult to find the defect and to make timely maintenance, and in extreme cases, unexpected suction of the contactor may occur and thus have unpredictable consequences. When the contactor with high-low side driving and bilateral control is used, misjudgment and missed judgment cannot be avoided by simply identifying loop current of a control feedback signal, so that the requirement of a functional safety level (such as ASIL B) on the diagnosis coverage rate can not be met, and the risk of potential functional safety failure still exists. Accordingly, there is a need for improvements in diagnostic strategies for contactors. Disclosure of Invention In order to address at least one of the problems mentioned above, the present disclosure proposes a method and apparatus that enables diagnostics specifically for high and low side drive controlled contactors, so that a more comprehensive monitoring of the contactor is achieved through high and low side joint diagnostics and fusion and meets the desired level of functional safety. According to an aspect of the present 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 presented, the method comprising obtaining a control feedback signal of the contactor, a contactor command status and fault bit data, determining whether the contactor is in a fault state based on the control feedback signal and the contactor command status, and determining at least one of a type and a position of the fault state based on the control feedback signal, the contactor command status and the fault bit data in case the contactor is in the fault state. According to another aspect of the present disclosure, an apparatus 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 provided, the apparatus comprising a high side drive unit and a low side drive unit configured to provide a high side drive control signal and a low side drive control signal for controlling the contactor, respectively, and to provide fault bit data of the contactor, a diagnostic unit configured to acquire a control feedback signal of the contactor, a contactor command status and fault bit data, determine whether the contactor is in a fault state based on the control feedback signal and the contactor command status, and determine at least one of a type and a position of the fault state based on the control feedback signal, the contactor command status and the fault bit data in case the contactor is in the fault state. According to yet another aspect of the disclosure, a computer-readable storage medium is presented, on which a computer program is stored, the computer program comprising executable instructions which, when executed by a processor, implement the method as described above. According to yet another aspe