Method and device for determining a fault of a hall sensor of an electric

Abstract

The present application relates to a method for determining a failure of a Hall sensor of an electric machine for a shift actuator of a vehicle having an electrically driven axle system integrating the electric machine, a decelerator and an inverter, the method comprising the following steps: after a shift control unit of the vehicle is first waken up, starting the motor, the decelerator and the inverter; and executing a Hall sensor self-check diagnosis process for the Hall sensor of the motor, and if the Hall sensor self-check diagnosis process is not passed, determining that the Hall sensor has a fault. The invention further relates to a device for determining the fault of the Hall sensor of the motor used for the gear shifting executing mechanism of the vehicle and an electric drive axle system of the vehicle. The fault of the Hall sensor of the DCA motor can be determined, and the fault diagnosis of the Hall sensor can be executed before gear shifting when the TCU is awakened for the first time, so that the possible gear shifting problem is avoided in advance.

Description

Technical Field

[0001] This application relates to an electric drive axle system using a shift actuator with a Hall sensor, and more particularly to a method and apparatus for determining a Hall sensor fault in the shift actuator within an electric drive axle system. Background Technology

[0002] With the development of modern automobiles, electric drive axle systems for electric vehicles have emerged. These systems combine a motor, inverter, and reducer to drive the vehicle. In such vehicles, when a gear shift is required, the transmission control unit (TCU) sends a gearbox shift command to the shift actuator (DCA), which then performs the shift operation via a shift fork or other mechanism.

[0003] For the motor used in the shift actuator, there are multiple, such as three, Hall sensors. These three Hall sensors can output high and low level signals based on the sensed changes in the motor's magnetic field, and determine the phase sequence of the motor based on the combination sequence of their signals.

[0004] However, for existing electric drive axle systems, the Hall sensors in the shift actuator do not support basic electrical diagnostics (OL / SCB / SCG, etc.) of the electric drive axle system. That is, when one or more of the multiple Hall sensors fail, for example, when the Hall sensor signal does not change, it is impossible to determine whether the Hall sensor is in a power-off stop state or a fault state. Especially after the TCU is first awakened, existing vehicles directly perform shift operations without prior detection of Hall sensor failure in the shift motor. Direct shift operations under Hall sensor failure may damage vehicle components.

[0005] Therefore, a method and apparatus are needed to accurately diagnose whether the Hall position sensor in the shift actuator of a vehicle's electric drive axle system is faulty, thereby ensuring the normal operation of the motor and increasing the vehicle's safety and reliability. In other words, the position sequence of the Hall sensor needs to be monitored in real time, both when the TCU is first activated and during each shift, in order to detect any potential electrical problems with the motor. Summary of the Invention

[0006] The purpose of this application is to provide an apparatus for accurately determining the fault of the Hall sensor of the shift actuator in the electric drive system of a vehicle in real time when the vehicle's TCU is awakened and during each shift operation.

[0007] To achieve the above objectives, this application provides a method for determining a Hall sensor fault in a motor of a vehicle's shift actuator, the vehicle having an electric drive axle system integrating a motor, a reducer, and an inverter. The method includes the following steps: after the vehicle's shift control unit is first awakened, performing a Hall sensor self-test diagnostic process for the Hall sensor of the motor; if the Hall sensor self-test diagnostic process fails, determining that the Hall sensor is faulty.

[0008] This application also relates to an apparatus for determining a Hall sensor fault in a motor of a vehicle's shift actuator, comprising: a shift control request module that issues a command to the shift actuator to perform a shift operation; and a Hall sensor self-test diagnostic module that performs a Hall sensor self-test diagnostic process for the Hall sensor after the vehicle's shift control unit is first awakened, to determine whether the motor's Hall sensor has malfunctioned.

[0009] This application also relates to an electric drive axle system for a vehicle, comprising a motor, an inverter, a reducer, and a shift assembly, the shift assembly including a shift control unit that issues commands to a shift actuator to control the operation of the shift actuator, wherein the electric drive axle system further includes the means described above for performing the method described above.

[0010] By adopting the solution of this application as described above, it is possible to detect potential electrical problems in the motor of the shift actuator in real time based on the changes between the Hall sensor signal sequence when the shift request is issued and the signal sequence after the motor rotor rotates forward and reverse. Even if the shift actuator does not move, it is possible to determine the fault of the Hall sensor of the DCA motor. Furthermore, the fault diagnosis of the Hall sensor can be performed before shifting when the TCU is first woken up, thus avoiding potential shifting problems in advance. Attached Figure Description

[0011] The embodiments of this application will be described in more detail with reference to the accompanying drawings, in which:

[0012] Figure 1 The diagram schematically illustrates the relationship between the position of the Hall sensor and the electrical signal in the vehicle's gear shift actuator;

[0013] Figure 2 A flowchart for detecting Hall sensor malfunctions is illustrated schematically.

[0014] Figure 3 The flowchart illustrating this function during the power-on self-test process is shown schematically; and

[0015] Figure 4 The flowchart illustrating the function's use for response diagnosis of the shift actuator is shown schematically. Detailed Implementation

[0016] In the following description, embodiments according to this application will be illustrated with reference to the accompanying drawings. The drawings are not drawn to scale, but some parts have been enlarged for clarity. Identical or similar features in the drawings will be indicated by the same reference numerals, and repeated descriptions will be omitted.

[0017] As mentioned earlier, for the electric drive axle system of a vehicle, the Hall sensors of the actuators (such as cams) of the existing shift actuators do not support basic electrical diagnostics (OL / SCB / SCG, etc.) in the electric drive axle system. In particular, the TCU does not perform fault diagnosis of the motor Hall sensor after its first wake-up, which leads to problems with vehicle shifting.

[0018] Figure 1 A schematic diagram of the motor phase sequence, represented by a sequence of signals transmitted by three Hall sensors, is shown.

[0019] The diagram illustrates three Hall sensors A, B, and C installed in the gear shift actuator. These three sensors generate high and low level signals, such as 0 or 1, under the influence of a changing magnetic field. The combined outputs of the three Hall sensor signals form six different numbers, constituting a sequence. For example, in... Figure 1 On the left, the three Hall sensors A, B, and C are all normal, and they output corresponding high-level or low-level signals 0 or 1 respectively. Therefore, the motor phase sequence composed of the signals output by the three normal Hall sensors is 1-3-2-6-4-5.

[0020] And such Figure 1 As shown on the right, if one of the Hall sensors, such as Hall sensor A, malfunctions, the signals emitted by Hall sensor A will all be low-level signals (0). Therefore, the motor phase sequence composed of the signals output by the three Hall sensors will become 0-2-2-6-4-4. However, existing electric drive axle systems, based on the current phase, provide control signals for the next phase. If the motor still does not rotate, the unit will still issue a control request to move to the next phase. Therefore, it is impossible to determine whether the problem is with the phase sequence or a mechanical problem with the shift actuator itself.

[0021] In order to accurately determine whether the Hall sensor is malfunctioning, this application... Figure 2 The diagram shows a flowchart of a method for detecting Hall sensor malfunctions in a vehicle.

[0022] like Figure 2As shown, starting from step S0, in step S1, it is determined whether the shift control unit is awakened for the first time to issue a command to the shift actuator. If so, in step S2, the "Hall sensor self-test diagnosis" process (also known as power-on self-test) of the brushless DC motor is executed, similar to the self-test process when the vehicle starts, to check whether the Hall sensor of the motor is faulty. If it is determined in step S3 that the Hall sensor of the motor is normal, that is, the Hall sensor self-test diagnosis passes, the vehicle is reported to be normal, the program ends in step S100, and subsequent normal shifting can be triggered; if it is determined in step S3 that the Hall sensor of the motor is not normal, that is, the Hall sensor self-test diagnosis fails, the process proceeds to step S4 to perform a limp response on the electric drive axle system and report the detection result to the vehicle control system so that the driver can react.

[0023] Accordingly, if the shift control unit (TCU) is not being woken up for the first time in step S1, the process proceeds to step S5 to determine whether the shift control unit needs to issue a regular shift request to the shift actuator. If not, the rationality of the motor phase sequence constituted by the Hall sensor signals is judged (whether all are high or low, i.e., phase sequence is 0 or 7). If the phase sequence is unreasonable, the Hall sensor phase sequence rationality monitoring fault is triggered, and the program ends. If it is reasonable, the program exits, allowing normal shifting to continue. If the shift control unit issues a regular shift request command to the shift actuator in step S5, the process proceeds to step S6 to perform the "actuator response diagnosis" process to respond to the DC brushless motor and determine whether the motor's Hall sensor is normal. If the Hall sensor of the motor is determined to be normal in step S7, that is, the actuator response diagnostic process is passed, the vehicle is reported to be normal, the program ends, and gear shifting can be performed normally; if the Hall sensor of the motor is determined to be abnormal in step S7, the process will proceed to step S8, and as in step S4, a limp response will be performed on the electric drive axle system, and the detection result will be reported to the vehicle control system so that the driver can react.

[0024] After determining that the Hall sensor of the motor is faulty, different operations can be performed for different electric drive axles and structures of the vehicle when performing a limp response for the electric drive axle system.

[0025] For example, when a vehicle has a single electric drive axle, depending on the number of BLDCs, it is advisable to maintain the original gear position and not perform any gear shifting operations after a Hall sensor failure of the motor occurs.

[0026] When a vehicle has dual or even quad electric drive axles, depending on the number of BLDCs, the actuator can switch the gear to a gear that is not faulty, or it can keep the original gear unchanged and not switch gears.

[0027] Of course, this is just an example. When a motor Hall sensor malfunctions, different procedures can be followed depending on the vehicle.

[0028] Figure 3 It schematically shows that in Figure 2 The flowchart in the flowchart is a detailed flowchart of the "Hall Sensor Self-Test Diagnosis" process performed in step S2, that is, the power-on self-test process to be performed when the vehicle's shift control unit is first woken up, in order to check whether the Hall sensor of the BLDC brushless motor is normal.

[0029] First, starting from step S00, in step S9, that is, after the TCU is first awakened, the shift actuator controls the rotor of the brushless DC motor to move forward a certain distance, for example, at least 1 rpm. Assuming the TCU sequentially issues the motor operation request, the signal sequence of the three Hall sensors is as follows: Figure 1 As shown in the diagram: 1-3-2-6-4-5, after moving 1 rpm, in step S10, it is determined whether the signal sequence received from the Hall sensor after the rotor moves forward is the same as the requested signal sequence (e.g., still 1-3-2-6-4-5). If there is no change, it is determined that the Hall sensor self-test diagnosis of the brushless DC motor has passed and there is no electrical problem. Then, in step S14, the rotor is returned to its original position. In step S15, it is confirmed that the Hall sensor self-test diagnosis of the BLDC has passed and there is no electrical problem. The diagnostic process ends in step S200.

[0030] Otherwise, if it is determined in step S10 that the Hall sensor signal sequence received after the rotor moves forward is inconsistent with the requested sequence (e.g., the Hall sensor signal sequence received after the rotor moves forward is incorrect due to a malfunction of Hall sensor A), Figure 1 If the signal sequence (0-2-2-6-4-4) shown on the right side of the diagram, or if it remains unchanged for a period of time after the drive current has been sent to the motor (e.g., always 4), then in step S11, the motor rotor is rotated in the reverse direction by at least 1 rpm, and the diagnostic is performed again. At this time, the Hall sensor request sequence is still, for example, 1-5-4-6-2-3. Then, in step S12, it is determined whether the Hall sensor signal sequence received after the rotor has rotated in the reverse direction by 1 rpm is the same as the request sequence. If they are the same (e.g., 1-5-4-6-2-3), then in step S15, it is determined that the Hall sensor self-test diagnostic of the BLDC has passed and there is no electrical problem. Otherwise, in step S13, it is determined that the Hall sensor self-test diagnostic has failed and there is an electrical problem with the BLDC. As mentioned above, a limp response is performed on the electric drive axle system, and the detection result is reported to the vehicle control system.

[0031] In the above process, the rotor is moved by a distance of 1 rpm in the forward or reverse direction as an example. However, this application is not limited to this and can move other distances, such as greater than 1 rpm, such as 2 rpm.

[0032] Figure 4 It schematically shows that in Figure 2 The flowchart shown is a detailed flowchart of the actuator response diagnosis process in step S6; that is, each time the shift control unit sends a shift request to the shift actuator, the shift actuator performs an "actuator response diagnosis" process similar to the Hall sensor self-test diagnosis (power-on self-test) process described above, to check whether the Hall sensor of the DC brushless motor is normal.

[0033] like Figure 4 As shown, starting from step S000, for each shift request issued by the TCU, the shift actuator must respond. In step S16, the shift control unit controls the rotor of the DC brushless motor of the shift actuator to move forward a certain distance, for example, 1 rpm. At this time, for example, the signal sequence of the Hall sensor when the shift request is made is... Figure 1 The sequence is 1-3-2-6-4-5 as shown on the left. Then, in step S17, it is determined whether the Hall sensor signal sequence received after the rotor moves forward is the same as the requested sequence. For example, it should still be 1-3-2-6-4-5. If there is no change, then in step S19, the actuator response diagnosis is deemed successful, thus finally determining that the BLDC Hall sensor has no electrical problem, and the process ends in step S300. Otherwise, if in step S17, the Hall phase sequence of the shift motor remains unchanged for a period of time based on the current phase sequence control drive current (e.g., always 4), the motor rotor will be controlled to rotate in the reverse direction, for example, 1 rpm. If the phase sequence remains unchanged for a period of time after the reverse rotation, then the Hall sensor is determined to be faulty. Alternatively, if the Hall sensor signal sequence of the shift actuator received in step S17 after the rotor moves forward is different from the requested sequence, for example, due to a fault in Hall sensor A... Figure 1 If the value shown on the right changes to 0-2-2-6-4-4), then in step S18 it is determined that the actuator response diagnosis failed, indicating that the Hall sensor of the DC brushless motor is faulty and there is an electrical problem with the motor. As mentioned above, a limp response is performed on the electric drive axle system and the detection result is reported to the vehicle control system.

[0034] In S16 above, the movement of the motor rotor can be forward or reverse, for example, a forward or reverse movement of 1 rpm. Of course, the movement distance is not limited to this; it can also be a distance greater than 1 rpm, such as 2 rpm.

[0035] The vehicle described in this application may be an electric vehicle, which also has an alarm device. After an electrical fault is detected in the Hall sensor of the motor according to the detection method of this application, the device sends a signal to the vehicle control unit to report the fault, so as to make appropriate adjustments to the control process of the shift actuator and protect the safety of the vehicle.

[0036] The Hall sensor detection method for the motor of the shift actuator described in this application enables the electric drive bridge system to directly identify electrical problems even if the specific actuators of the shift actuator, such as the cam and shift fork, do not move substantially after the TCU issues a shift request command to the DCA, when the Hall sensor malfunctions.

[0037] This facilitates the support and maintenance of vehicle parts, protects the electric drive axle system from unwanted damage, and improves the overall vehicle safety.

[0038] Although the present invention has been described with reference to preferred embodiments, this is not intended to limit the invention. It should be understood that the scope of protection of the present invention is defined by the appended claims, and various modifications can be made by those skilled in the art without departing from this scope.

Claims

1. A method for determining a Hall sensor failure in a motor of a shift actuator for a vehicle, the vehicle having an electric drive axle system integrating a motor, a reducer, and an inverter, the method comprising the steps of: After the vehicle's shift control unit is first awakened, a Hall sensor self-test diagnostic process is performed for the Hall sensor of the motor. If the Hall sensor self-test diagnostic process fails, it is determined that the Hall sensor is faulty.

2. The method according to claim 1 further includes performing a shift actuator response diagnostic process each time the shift control unit issues a shift request to the shift actuator; if the shift actuator response diagnostic process fails, the Hall sensor is determined to be faulty.

3. The method according to claim 1 or 2, wherein, The Hall sensor self-test diagnostic process includes the following steps: The rotor of the motor of the shift actuator is rotated a certain distance in a first direction. It is determined whether the motor phase sequence represented by the Hall sensor signal received after the rotor rotates in the first direction has changed compared with the motor phase sequence when the shift request was issued. If it has changed, the motor rotor is rotated a certain distance in a second direction different from the first direction. It is then determined whether the motor phase sequence received after the rotor rotates in the second direction is the same as the motor phase sequence when the shift request was issued. If they are different, it is determined that the Hall sensor self-test diagnosis process has failed.

4. The method according to claim 2, wherein the shift actuator response diagnostic process includes the following steps: The rotor of the motor of the shift actuator is rotated a certain distance in a first direction. It is determined whether the motor phase sequence represented by the Hall sensor signal received after the rotor rotates in the first direction has changed compared with the motor phase sequence when the shift request was issued. If it has changed, the motor rotor is rotated a certain distance in a second direction different from the first direction. It is then determined whether the motor phase sequence received after the rotor rotates in the second direction is the same as the motor phase sequence when the shift request was issued. If they are different, it is determined that the shift actuator response diagnostic process has failed.

5. The method according to any one of claims 1-4, further comprising performing limp control on the electric drive axle system when it is determined that the Hall sensor has failed, wherein performing limp control on the electric drive axle system includes maintaining the current gear position unchanged.

6. The method according to claim 5, wherein, Limp control is performed on a single electric drive bridge system, or on dual electric drive bridges, or multiple electric drive bridges.

7. The method according to any one of claims 3-6, wherein, The rotor of the motor is rotated by 1 rpm or more in a first or second direction.

8. An apparatus for determining a Hall sensor malfunction in a motor of a vehicle's shift actuator, comprising: The shift control request module sends commands to the shift actuator to execute the shift operation. The Hall sensor self-test diagnostic module performs a Hall sensor self-test diagnostic process after the vehicle's shift control unit is first woken up to determine whether the Hall sensor of the motor is faulty.

9. The apparatus according to claim 8 further includes a shift actuator response diagnosis module, which performs a shift actuator response diagnosis process each time the shift actuator performs a shift operation in response to an instruction from the shift control unit, to determine whether the Hall sensor of the motor is faulty.

10. The apparatus according to claim 8 or 9, wherein, The Hall sensor self-test diagnostic module determines whether the Hall sensor is faulty through the following process: the motor rotor is rotated a certain distance in the first direction and the motor phase sequence represented by the Hall sensor signal received after rotation is compared with the motor phase sequence when the shift request is issued. When the phase sequence changes, the rotor is moved in the second direction and the phase sequence is determined again. The Hall sensor is then determined to be faulty based on the phase sequence change.

11. The apparatus of claim 9, wherein the shift actuator response diagnostic module determines whether the Hall sensor is faulty by the following process: rotating the rotor of the motor along a first direction for a certain distance and comparing the motor phase sequence represented by the Hall sensor signal received after rotation with the motor phase sequence when the shift request is issued; moving the rotor along a second direction when the phase sequence changes, and determining again whether the phase sequence has changed; and determining whether the Hall sensor is faulty based on the phase sequence change.

12. The apparatus according to claim 10 or 11, wherein, The rotor is rotated by 1 rpm or more in a first or second direction.

13. The apparatus according to any one of claims 8-12, wherein, The motor is a DC brushless motor.

14. An electric drive axle system for a vehicle, comprising a motor, an inverter, a reducer, and a shift assembly, the shift assembly including a shift control unit that issues commands to a shift actuator to control the operation of the shift actuator, wherein the electric drive axle system further comprises means according to any one of claims 8-13, the means being used to perform the method according to any one of claims 1-7.

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