Electronic oil pump control method

Abstract

The invention discloses an electronic oil pump control method, and relates to the field of electronic oil pumps, the control method comprises the following steps: when a brushless motor is powered on, a controller is awakened, and the controller controls the brushless motor to enter a stop state; the controller generates a control signal according to an external control instruction; if the duty ratio of the control signal is 10%, the brushless motor is controlled to enter a stop state; if the duty ratio of the control signal is 20%-90%, the brushless motor is controlled to enter a starting state; and in the starting process of the brushless motor, if the rotating speed of the brushless motor reaches a first preset rotating speed or above when the brushless motor is started for a first preset time, controlling the brushless motor to enter a working state. According to the invention, the brushless motor can be accurately controlled to enter a shutdown, starting or working state, and the stable work of the brushless motor is ensured, so that the stable work of the electronic oil pump is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic oil pumps, and in particular to an electronic oil pump control method. Background Art

[0002] In order to improve accuracy and reduce energy consumption, automobiles use electronic oil pumps instead of mechanical oil pumps. However, the electronic oil pumps currently on the market have problems such as complex control interfaces, high power consumption when in sleep mode, inaccurate speed control, and imperfect abnormal situation handling. Summary of the invention

[0003] In order to solve the technical problems existing in the background technology, the present invention proposes an electronic oil pump control method.

[0004] An electronic oil pump control method proposed in the present invention is applied to an electronic oil pump system, comprising: the electronic oil pump system comprises: an oil pump, a brushless motor and a controller, the brushless motor and the oil pump are mechanically directly connected, and the controller and the brushless motor are electrically connected; wherein the brushless motor comprises stop, start and working states;

[0005] The control method comprises:

[0006] When the brushless motor is powered on, the controller is awakened, and the controller controls the brushless motor to enter a stop state;

[0007] The controller generates a control signal according to an external control instruction;

[0008] If the duty cycle of the control signal is 10%, the brushless motor is controlled to enter a stop state;

[0009] If the duty cycle of the control signal is 20% to 90%, the brushless motor is controlled to enter the starting state;

[0010] During the start-up process of the brushless motor, if the rotation speed of the brushless motor reaches or exceeds the first preset rotation speed when the brushless motor starts for the first preset time, the brushless motor is controlled to enter a working state.

[0011] Preferably, when the brushless motor enters the working state, if the rotation speed of the brushless motor is less than a first preset rotation speed, the controller controls the brushless motor to enter the stopping state.

[0012] Preferably, when the brushless motor enters the working state or the starting state and the speed of the brushless motor is greater than the first preset speed, if the controller generates a control signal with a duty cycle of 10% according to an external control instruction, the controller controls the brushless motor to continuously decelerate according to the control signal with a duty cycle of 10%, so as to decelerate to within the first preset speed within a second preset time, and then control the brushless motor to enter the stop state; wherein the second preset time is less than the first preset time.

[0013] Preferably, after the brushless motor enters the working state, when the oil pump completes its work, the external controller sends work completion information to the controller;

[0014] The control module generates a control signal with a duty cycle of 10% according to the work completion information, and controls the brushless motor to continuously decelerate according to the control signal with a duty cycle of 10%, so as to decelerate to within the first preset speed within the second preset time, and then controls the brushless motor to enter a stop state;

[0015] When the brushless motor enters the stop state, the controller sends a power-off command to the brushless motor, the brushless motor is powered off, and the controller enters the sleep state.

[0016] Preferably, after the brushless motor enters the startup or working state, the controller is further used to obtain a feedback signal of the brushless motor, and determine whether the brushless motor or the controller fails according to the feedback signal:

[0017] When a fault is determined to have occurred, the controller generates a fault code and controls the brushless motor to enter a stop state.

[0018] Preferably, the fault includes one or more of an overtemperature of the brushless motor, an abnormal control signal of the controller, a failure to start the brushless motor, an undervoltage or overvoltage of the power supply voltage of the brushless motor, and an overcurrent of the brushless motor.

[0019] Preferably, judging whether the brushless motor or the controller fails according to the feedback signal specifically includes:

[0020] According to the feedback signal, a duty cycle of the feedback signal is obtained;

[0021] When the duty cycle of the feedback signal is 10%, it is determined that the brushless motor hardware circuit is faulty;

[0022] When the duty cycle of the feedback signal is 20%, it is determined that the temperature of the brushless motor is too high;

[0023] When the duty cycle of the feedback signal is 60%, it is determined that the control signal of the controller is abnormal;

[0024] When the duty cycle of the feedback signal is 70%, it is determined that the brushless motor fails to start;

[0025] When the duty cycle of the feedback signal is 80%, it is determined that the power supply voltage of the brushless motor is undervoltage or overvoltage;

[0026] When the duty cycle of the feedback signal is 90%, it is determined that the brushless motor has an overcurrent.

[0027] Preferably, when it is determined that the brushless motor hardware circuit fails, before the brushless motor enters a dormant state or is powered off, a fault code corresponding to the brushless motor hardware circuit failure is continuously output; when the brushless motor hardware circuit failure is resolved, the brushless motor is powered on again;

[0028] When it is determined that the temperature of the brushless motor is too high, if the brushless motor enters a stopped state, when the temperature of the brushless motor is lower than the first preset temperature and lasts for a third preset time or longer, the fault code corresponding to the over-high temperature of the brushless motor is cleared, and the brushless motor is controlled to automatically restart; wherein the third preset time is greater than the first preset time;

[0029] When it is determined that the brushless motor has an overcurrent, if the brushless motor enters the stop state after a fourth preset time, the fault code corresponding to the overcurrent of the brushless motor is cleared; if the control command input to the controller is still to control the brushless motor to run, the controller controls the brushless motor to automatically restart; wherein the fourth preset time is greater than the third preset time;

[0030] When the control signal of the controller is determined to be abnormal, if the brushless motor enters the stopped state, the controller regenerates the control signal that meets the preset requirements according to the external control command, clears the fault code corresponding to the control signal communication abnormality, and controls the brushless motor to automatically restart;

[0031] When it is determined that the brushless motor fails to start, if the brushless motor enters a stopped state and continues for a first preset time, and the control signal generated by the controller according to the external control instruction is still for controlling the brushless motor to run, the brushless motor is controlled to automatically restart to clear the startup failure fault;

[0032] When it is determined that the power supply voltage of the brushless motor is undervoltage or overvoltage, the bus voltage of the brushless motor is adjusted between the second preset voltage and the third preset voltage, and the duration is longer than the fourth preset time, and the fault code corresponding to the undervoltage or overvoltage of the power supply voltage of the brushless motor is cleared; if the control instruction input to the controller at this time is still to control the operation of the brushless motor, the controller controls the brushless motor to automatically restart; wherein, the third preset voltage is greater than the second preset voltage.

[0033] Preferably, the priority order of the faults is from high to low: undervoltage or overvoltage of the power supply voltage of the brushless motor, hardware circuit failure of the brushless motor, overtemperature of the brushless motor, abnormal control signal of the controller, overcurrent of the brushless motor, and failure to start the brushless motor;

[0034] When two or more faults occur at the same time, they are handled in order of priority.

[0035] Preferably, the control signal is a PWM signal in a first preset frequency range, the feedback signal is a PWM signal in a second preset frequency range, and the second preset frequency range is smaller than the first preset frequency range.

[0036] In the present invention, the proposed electronic oil pump control method can accurately control the brushless motor to enter the shutdown, startup or working state, which is conducive to ensuring the stable operation of the brushless motor and thus ensuring the stable operation of the electronic oil pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The figure is a flow chart of an electronic oil pump control method proposed by the present invention. DETAILED DESCRIPTION

[0038] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0039] Reference Figure 1 , an electronic oil pump control method proposed in the present invention is applied to an electronic oil pump system, the electronic oil pump system comprises: an oil pump, a brushless motor, and a controller, the brushless motor and the oil pump are mechanically directly connected, and the controller and the brushless motor are electrically connected;

[0040] The motor includes stop, start and working status;

[0041] When the brushless motor is powered on, the controller is awakened and the controller immediately controls the brushless motor to enter the stop state;

[0042] The controller is also used to generate a control signal according to an external control instruction;

[0043] If the duty cycle of the control signal is 10%, the drive module controls the brushless motor to enter a stop state according to the control signal;

[0044] If the duty cycle of the control signal is between 20% and 90%, the brushless motor is controlled to enter the starting state;

[0045] During the start-up process of the brushless motor, if the rotation speed of the brushless motor reaches or exceeds the first preset rotation speed when the brushless motor starts for the first preset time, the brushless motor is controlled to enter a working state.

[0046] The present invention can accurately control the brushless motor to enter a shutdown, startup or working state, which is beneficial to ensuring the stable operation of the brushless motor and thus ensuring the stable operation of the oil pump.

[0047] In this embodiment, when the brushless motor enters the working state, if the rotation speed of the brushless motor is less than the first preset rotation speed, the controller controls the brushless motor to enter the stopping state.

[0048] In order to reduce power consumption, in this embodiment, when the brushless motor is in a working state and the speed of the brushless motor is greater than a first preset speed, if the controller generates a control signal with a duty cycle of 10 according to an external control instruction, the controller controls the brushless motor to continuously decelerate according to the control signal with a duty cycle of 10, so as to decelerate to within the first preset speed within a second preset time, and then controls the brushless motor to enter a stop state.

[0049] In order to reduce power consumption and ensure the stability of the brushless motor during operation, in this embodiment, after the brushless motor enters the working state, when the oil pump completes the work, the external controller sends a work completion information to the controller, and the controller generates a control signal with a duty cycle of 10% according to the work completion information; the controller controls the brushless motor to continue to decelerate according to the control signal with a duty cycle of 10%, so as to decelerate to within the first preset speed within the second preset time, and then control the brushless motor to enter the stop state; wherein the second preset time is less than the first preset time; when the working state of the brushless motor obtained by the controller is the stop state, the controller sends a power-off command to the brushless motor, the brushless motor is powered off, and the controller enters the sleep state.

[0050] In order to promptly handle the abnormality that occurs during the operation of the brushless motor, in this embodiment, after the brushless motor enters the startup or working state, the controller is also used to obtain the feedback signal of the brushless motor, and determine whether the brushless motor or the controller fails according to the feedback signal:

[0051] When a fault is determined to have occurred, the controller generates a fault code and controls the brushless motor to enter a stop state.

[0052] In this embodiment, the fault includes one or more of the following: overtemperature of the brushless motor, abnormal control signal of the controller, failure to start the brushless motor, undervoltage or overvoltage of the power supply voltage of the brushless motor, and overcurrent of the brushless motor.

[0053] Therefore, when the duty cycle of the feedback signal is 10%, it is determined that the brushless motor hardware circuit is faulty.

[0054] When the duty cycle of the feedback signal is 20%, it is determined that the temperature of the brushless motor is too high;

[0055] When the duty cycle of the feedback signal is 60%, it is determined that the control signal of the controller is abnormal;

[0056] When the duty cycle of the feedback signal is 70%, it is determined that the brushless motor fails to start;

[0057] When the duty cycle of the feedback signal is 80%, it is determined that the power supply voltage of the brushless motor is undervoltage or overvoltage;

[0058] When the duty cycle of the feedback signal is 90%, it is determined that the brushless motor has an overcurrent.

[0059] When there is only one fault state, the duration of the feedback signal output is fixed, and the duration of each feedback signal is at or above the second preset time; when there are multiple fault states, the feedback signals of all current fault states will be cyclically output, and each feedback signal will last for the second preset time.

[0060] Among them, if the duty cycle of the feedback signal is 10%, it indicates that the thermistor circuit of the brushless motor is abnormal or the bus current detection circuit is abnormal. When the thermistor is damaged (open circuit or short circuit), it cannot detect the temperature normally or the bus current detection circuit is abnormal. When the brushless motor is working, its ADC cannot detect the current normally, and it is considered that the thermistor circuit of the brushless motor is abnormal or the bus current detection circuit is abnormal. If the brushless motor is working at this time, the brushless motor is controlled to enter the stop state.

[0061] When it is determined that the brushless motor hardware circuit is faulty, the fault code corresponding to the brushless motor hardware circuit fault is continuously output before the brushless motor enters the sleep state or is powered off; when the brushless motor hardware circuit fault is resolved, the brushless motor is powered on again.

[0062] When the duty cycle of the feedback signal is 20%, it indicates that the temperature of the brushless motor is too high. When the coil temperature of the brushless motor exceeds the second preset temperature for more than the third preset time, it is considered that the temperature of the brushless motor is too high. If the brushless motor is working at this time, the brushless motor is controlled to enter a stop state.

[0063] When it is determined that the temperature of the brushless motor is too high, if the brushless motor enters a stopped state, when the temperature of the brushless motor is lower than the first preset temperature and lasts for a third preset time or more, the fault code corresponding to the high temperature of the brushless motor is cleared, and the brushless motor is controlled to automatically restart; wherein, the third preset time is greater than the first preset time, and the first preset temperature is lower than the second preset temperature.

[0064] Specifically, the first preset time temperature is 140°C, and the second preset temperature is 150°C.

[0065] If the duty cycle of the feedback signal is 60%, it indicates that the control signal of the controller is abnormal. When the control signal input to the brushless motor is not within the first preset frequency range, or the duty cycle of the control signal is not within the range of 5% to 95%, it is considered that the control signal of the controller is abnormal. If the brushless motor is working at this time, the brushless motor is controlled to enter a stopped state.

[0066] When the controller's control signal is determined to be abnormal, if the brushless motor enters the stop state, the controller regenerates the control signal that meets the preset requirements according to the external control command, clears the fault code corresponding to the control signal communication abnormality, and controls the brushless motor to automatically restart. Among them, the preset requirements are that the frequency range of the control signal is 90Hz to 110Hz, the signal duty cycle range is 5% to 95%, and the duration is more than 1s.

[0067] If the duty cycle of the feedback signal is 70%, it indicates that the brushless motor fails to start. When the brushless motor is in the startup phase and cannot enter closed-loop operation normally (the motor stops during the startup phase, or the speed does not reach the minimum operating speed after the startup phase time ends), it is considered that the brushless motor fails to start, and the brushless motor is controlled to enter the stop state.

[0068] When it is determined that the brushless motor fails to start, if the brushless motor enters a stopped state and continues for a first preset time, the control signal generated by the controller according to the external control instruction is still used to control the operation of the brushless motor, clear the fault code corresponding to the failure to start the brushless motor, and control the brushless motor to automatically restart.

[0069] Wherein, if the duty cycle of the feedback signal is 80%, it indicates that the power supply voltage of the brushless motor is undervoltage or overvoltage. Specifically, when the bus voltage of the brushless motor is higher than the fourth preset voltage or lower than the first preset voltage, and the duration is longer than the fourth preset time, it is considered that the power supply voltage of the brushless motor is undervoltage or overvoltage. Wherein, the first preset voltage is less than the fourth preset voltage. If the brushless motor is working at this time, the brushless motor is controlled to enter a stop state.

[0070] When it is determined that the power supply voltage of the brushless motor is undervoltage or overvoltage, the bus voltage of the brushless motor is adjusted between the second preset voltage and the third preset voltage, and the duration is longer than the fourth preset time, and the fault code corresponding to the undervoltage or overvoltage of the power supply voltage of the brushless motor is cleared; if the control instruction input to the controller at this time is still to control the operation of the brushless motor, the controller controls the brushless motor to automatically restart.

[0071] Among them, the first preset voltage<the second preset voltage<the third preset voltage<the fourth preset voltage.

[0072] Specifically, the first preset voltage is 8.5V, the second preset voltage is 9V, the third preset voltage is 16V, and the fourth preset voltage is 16.5V.

[0073] If the duty cycle of the feedback signal is 90%, it indicates that the brushless motor is in overcurrent protection. Specifically, when the bus current is higher than 8A in each commutation cycle of the motor or the average bus current of the motor exceeds 7A within 500ms, it is considered to be an overcurrent fault; if the brushless motor is working at this time, the brushless motor is controlled to enter a stop state.

[0074] When it is determined that the brushless motor has an overcurrent, if the brushless motor enters the stop state after the fourth preset time, the fault code corresponding to the overcurrent of the brushless motor is cleared; if the control instruction input to the controller is still to control the operation of the brushless motor, the controller controls the brushless motor to automatically restart; wherein the fourth preset time is greater than the third preset time.

[0075] Specifically, the fourth preset time is 1000 ms, the third preset time is 600 ms, the first preset time is 400 ms, the second preset time is 300 ms, and the first preset rotation speed is 1000 rpm.

[0076] In this embodiment, the control signal is a PWM signal in a first preset frequency range, the feedback signal is a PWM signal in a second preset frequency range, and the second preset frequency range is smaller than the first preset frequency range.

[0077] Specifically, the brushless motor in this embodiment adopts dual closed-loop PI control of current and speed. The priority of current control is higher than speed control. The duty cycle in a given control signal will limit the speed and output electric power of the brushless motor. The combined control of speed and power can achieve appropriate oil pressure and flow output.

[0078] In summary, the electronic oil pump control method proposed in the present invention has precise control conditions, accurate feedback, perfect fault detection, simple hardware communication interface, can adapt to most working conditions, effectively ensures stability during operation, and reduces power consumption.

[0079] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An electronic oil pump control method, characterized in that: Applied to an electronic oil pump system, characterized in that it includes: the electronic oil pump system includes: an oil pump, a brushless motor and a controller, the brushless motor and the oil pump are mechanically directly connected, and the controller and the brushless motor are electrically connected; wherein the brushless motor includes shutdown, start-up and working states; The control method comprises: When the brushless motor is powered on, the controller is awakened, and the controller controls the brushless motor to enter a stop state; The controller generates a control signal according to an external control instruction; If the duty cycle of the control signal is 10%, the brushless motor is controlled to enter a stop state; If the duty cycle of the control signal is 20% to 90%, the brushless motor is controlled to enter the starting state; During the start-up process of the brushless motor, if the rotation speed of the brushless motor reaches or exceeds the first preset rotation speed when the brushless motor starts for the first preset time, the brushless motor is controlled to enter a working state.

2. The electronic oil pump control method according to claim 1, characterized in that: When the brushless motor enters the working state, if the rotation speed of the brushless motor is less than the first preset rotation speed, the controller controls the brushless motor to enter the stopping state.

3. The electronic oil pump control method according to claim 1, characterized in that: When the brushless motor enters the working state or the starting state and the speed of the brushless motor is greater than the first preset speed, if the controller generates a control signal with a duty cycle of 10% according to an external control instruction, the controller controls the brushless motor to continue to decelerate according to the control signal with a duty cycle of 10%, so as to decelerate to within the first preset speed within the second preset time, and then control the brushless motor to enter the stop state; wherein the second preset time is less than the first preset time.

4. The electronic oil pump control method according to claim 1, characterized in that: After the brushless motor enters the working state, when the oil pump completes its work, the external controller sends a work completion message to the controller; The control module generates a control signal with a duty cycle of 10% according to the work completion information, and controls the brushless motor to continuously decelerate according to the control signal with a duty cycle of 10%, so as to decelerate to within the first preset speed within the second preset time, and then controls the brushless motor to enter a stop state; When the brushless motor enters the stop state, the controller sends a power-off command to the brushless motor, the brushless motor is powered off, and the controller enters the sleep state.

5. The electronic oil pump control method according to claim 1, characterized in that: After the brushless motor enters the startup or working state, the controller is also used to obtain the feedback signal of the brushless motor and determine whether the brushless motor or controller fails based on the feedback signal: When a fault is determined to have occurred, the controller generates a fault code and controls the brushless motor to enter a stop state.

6. The electronic oil pump control method according to claim 5, characterized in that: The faults include one or more of the following: the temperature of the brushless motor is too high, the control signal of the controller is abnormal, the starting failure of the brushless motor, the power supply voltage of the brushless motor is undervoltage or overvoltage, and the brushless motor has an overcurrent.

7. The electronic oil pump control method according to claim 6, characterized in that: Determine whether the brushless motor or controller is faulty based on the feedback signal, including: According to the feedback signal, a duty cycle of the feedback signal is obtained; When the duty cycle of the feedback signal is 10%, it is determined that the brushless motor hardware circuit is faulty; When the duty cycle of the feedback signal is 20%, it is determined that the temperature of the brushless motor is too high; When the duty cycle of the feedback signal is 60%, it is determined that the control signal of the controller is abnormal; When the duty cycle of the feedback signal is 70%, it is determined that the brushless motor fails to start; When the duty cycle of the feedback signal is 80%, it is determined that the power supply voltage of the brushless motor is undervoltage or overvoltage; When the duty cycle of the feedback signal is 90%, it is determined that the brushless motor has an overcurrent.

8. The electronic oil pump control method according to claim 6, characterized in that: When it is determined that the brushless motor hardware circuit is faulty, the fault code corresponding to the brushless motor hardware circuit fault is continuously output before the brushless motor enters the sleep state or is powered off; when the brushless motor hardware circuit fault is resolved, the brushless motor is powered on again; When it is determined that the temperature of the brushless motor is too high, if the brushless motor enters a stopped state, when the temperature of the brushless motor is lower than the first preset temperature and lasts for a third preset time or longer, the fault code corresponding to the over-high temperature of the brushless motor is cleared, and the brushless motor is controlled to automatically restart; wherein the third preset time is greater than the first preset time; When it is determined that the brushless motor has an overcurrent, if the brushless motor enters the stop state after a fourth preset time, the fault code corresponding to the overcurrent of the brushless motor is cleared; if the control command input to the controller is still to control the brushless motor to run, the controller controls the brushless motor to automatically restart; wherein the fourth preset time is greater than the third preset time; When the control signal of the controller is determined to be abnormal, if the brushless motor enters the stopped state, the controller regenerates the control signal that meets the preset requirements according to the external control command, clears the fault code corresponding to the control signal communication abnormality, and controls the brushless motor to automatically restart; When it is determined that the brushless motor fails to start, if the brushless motor enters a stopped state and continues for a first preset time, and the control signal generated by the controller according to the external control instruction is still for controlling the brushless motor to run, the brushless motor is controlled to automatically restart to clear the startup failure fault; When it is determined that the power supply voltage of the brushless motor is undervoltage or overvoltage, the bus voltage of the brushless motor is adjusted between the second preset voltage and the third preset voltage, and the duration is longer than the fourth preset time, and the fault code corresponding to the undervoltage or overvoltage of the power supply voltage of the brushless motor is cleared; if the control instruction input to the controller at this time is still to control the operation of the brushless motor, the controller controls the brushless motor to automatically restart; wherein, the third preset voltage is greater than the second preset voltage.

9. The electronic oil pump control method according to claim 5, characterized in that: The priority of the faults is arranged from high to low as follows: undervoltage or overvoltage of the brushless motor power supply voltage, brushless motor hardware circuit failure, brushless motor overtemperature, abnormal control signal of the controller, brushless motor overcurrent, and brushless motor startup failure; When two or more faults occur at the same time, they are handled in order of priority.

10. The electronic oil pump control method according to claim 5, characterized in that: The control signal is a PWM signal in a first preset frequency range, and the feedback signal is a PWM signal in a second preset frequency range, and the second preset frequency range is smaller than the first preset frequency range.

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