Vehicle control method, device and vehicle

Abstract

This invention provides a vehicle control method, device, and vehicle. The method includes: acquiring a target operating current of at least one phase of a vehicle drive motor; integrating the target operating current based on its magnitude and direction to obtain an integral current value; and controlling the drive motor to enter a stalled operating mode if the integral current value meets a preset stall condition. This invention dynamically determines stall faults by analyzing the current direction and value of each phase of the motor, significantly improving the stall fault detection rate and enabling rapid and effective stall protection of the motor.

Description

Technical Field

[0001] This invention relates to the field of electric vehicle control technology, and in particular to a vehicle control method, device, and vehicle. Background Technology

[0002] Currently, electric vehicles have become the mainstream trend in the automotive industry. When an electric vehicle is on a steep incline or unable to move forward from a slope, the drive motor may stall, causing the vehicle to roll backward. If the driver doesn't react quickly enough or makes incorrect driving maneuvers out of panic, it can easily lead to an accident. Furthermore, when the drive motor stalls, the current inside the drive motor controller increases sharply, causing overheating until it reaches the physical load limit of the drive motor controller module, potentially damaging the drive motor. Therefore, identifying drive motor stall faults is crucial for safe driving on slopes.

[0003] Existing technologies generally set an upper limit for current, and determine that the drive motor is stalled when the current reaches the set current value, and then drive the drive motor controller to enter protection mode; or they use an upper limit for temperature, and determine that the drive motor is stalled when the drive motor temperature reaches the set temperature value, and drive the drive motor controller to enter protection mode; or they use a combination of speed threshold and current threshold to determine stall.

[0004] The above-mentioned method of setting an upper limit for current cannot adapt to the complex operating conditions of the drive motor, and is likely to cause waste of IGBT module resources or damage to the driver module or drive motor. Furthermore, because temperature values ​​have a hysteresis, the solution of setting an upper limit for temperature cannot effectively prevent the drive motor from being stalled and causing damage to the drive motor. Summary of the Invention

[0005] This invention provides a vehicle control method, device, and vehicle to address the problem that existing methods for identifying drive motor stall faults are not efficient enough, resulting in an inability to effectively protect the drive motor from stall.

[0006] In a first aspect, embodiments of the present invention provide a vehicle control method, the method comprising:

[0007] Collect the target operating current of at least one phase of the vehicle drive motor;

[0008] Based on the magnitude and direction of the target operating current, the target operating current is integrated to obtain the current integral value;

[0009] If the integral value of the current meets the preset stall condition, the drive motor is controlled to enter the stall working mode.

[0010] Optionally, integrating the target operating current based on its magnitude and direction includes:

[0011] If the target operating current does not change direction within a first preset time period, and the target operating current is greater than a preset current threshold, then the target operating current is integrated.

[0012] Optionally, the integral value of the current satisfies a preset stall condition, including:

[0013] Obtain the current integration threshold;

[0014] When the integral value of the current exceeds the integral threshold of the current, counting is triggered.

[0015] If the number of consecutive trigger counts reaches the preset count threshold, the stall condition is satisfied.

[0016] Optionally, obtaining the current integration threshold includes:

[0017] The system acquires the first actual temperature of the power transistor, the stall carrier frequency, the stall current limit, and the second actual temperature of the drive motor; the power transistor is electrically connected to the drive motor and is used to invert the DC power output from the power supply into AC power before sending it to the drive motor;

[0018] The current integration threshold is determined based on the first actual temperature, the stall current limit, the second actual temperature, and the stall carrier frequency.

[0019] Optionally, the current integration threshold is determined based on the first actual temperature, the stall current limit, the second actual temperature, and the stall carrier frequency, including:

[0020] The first temperature coefficient of the power transistor is determined based on the first actual temperature, the upper limit of the first temperature that the power transistor can withstand, and the lower limit of the first temperature.

[0021] The second temperature coefficient of the drive motor is determined based on the second actual temperature, the upper limit of the second temperature that the drive motor can withstand, and the lower limit of the second temperature.

[0022] The current integration threshold is determined based on the product of the first temperature coefficient, the second temperature coefficient, the stall current limit, and the stall carrier frequency.

[0023] Optionally, controlling the drive motor to enter a stalled operating mode includes at least one of the following:

[0024] A stall alarm is generated based on the stall status of the drive motor;

[0025] Increase the cooling intensity of the drive motor;

[0026] The drive motor is protected against stall.

[0027] Optionally, the drive motor is protected against stall, including:

[0028] Calculate the stall torque required for the vehicle;

[0029] Based on the peak torque of the drive motor, the stall torque, and the target torque, the drive motor is controlled to output actual torque, wherein the peak torque is the upper limit of the torque output by the drive motor, and the target torque is the torque determined according to the accelerator switch.

[0030] Optionally, the required stall torque for the vehicle is calculated, including:

[0031] Obtain the vehicle's mass, tilt angle, speed ratio coefficient, and gravitational acceleration;

[0032] The stall torque is determined by mass * gravitational acceleration * sin(horizontal tilt angle) / speed ratio coefficient.

[0033] Optionally, based on the peak torque of the drive motor, the stall torque, and the user's target torque, the drive motor is controlled to output an actual torque, including:

[0034] When the stall torque is greater than the peak torque, the stall torque is set to the peak torque;

[0035] When the target torque is greater than the stall torque, the drive motor is controlled to output an actual torque equal to the stall torque.

[0036] When the target torque is less than or equal to the stall torque, the drive motor is controlled to output the actual torque as the target torque.

[0037] Optionally, after the drive motor enters the stall mode, the method further includes:

[0038] When the speed of the drive motor is greater than the upper limit of the stall speed and the duration is greater than or equal to the second preset duration, the drive motor is controlled to exit the stall working mode;

[0039] The upper limit of the stall speed is the upper limit of the speed of the drive motor when it is in a stall state.

[0040] In a second aspect, embodiments of the present invention provide a vehicle control device, the device comprising:

[0041] The acquisition module is used to acquire the target operating current of at least one phase of the vehicle drive motor;

[0042] An integration module is used to integrate the target operating current based on its magnitude and direction to obtain an integral value.

[0043] The control module is used to control the drive motor to enter the stall working mode if the integral value of the current meets the preset stall condition.

[0044] Thirdly, embodiments of the present invention provide an electronic device, including: a processor, a communication interface, a memory, and a communication bus; wherein the processor, the communication interface, and the memory communicate with each other through the communication bus;

[0045] Memory, used to store computer programs;

[0046] When the processor executes the program stored in the memory, it implements the steps in the vehicle control method described in the first aspect above.

[0047] Fourthly, embodiments of the present invention provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the vehicle control method described in the first aspect.

[0048] Fifthly, embodiments of the present invention provide a vehicle that includes the vehicle control device described above.

[0049] Compared with prior art, the present invention has the following advantages:

[0050] In this embodiment of the invention, the target operating current of at least one phase of the vehicle drive motor is continuously collected; based on the magnitude and direction of the target operating current, the target operating current is integrated to obtain the integrated current value; if the integrated current value meets a preset stall condition, the drive motor is controlled to enter a stall operating mode. Because the current values ​​of each phase of the drive motor have high real-time performance, dynamically judging stall faults by integrating the current direction and value of each phase of the drive motor can greatly improve the stall fault judgment rate, thereby quickly and effectively protecting the drive motor from stall.

[0051] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0053] Figure 1This is a flowchart illustrating a vehicle control method provided in an embodiment of the present invention.

[0054] Figure 2 A schematic diagram of a vehicle control device provided in an embodiment of the present invention;

[0055] Figure 3 A block diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0056] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0057] To identify stall faults in the drive motors of electric vehicles, a current upper limit can be set first. Once the current reaches the set value, the drive motor is determined to be stalled, and the drive motor controller is then driven into protection mode. Alternatively, a temperature upper limit can be set first. Once the drive motor temperature reaches the set value, the drive motor is determined to be stalled, and the drive motor controller is then driven into protection mode. Stall detection can also be performed by combining speed and current thresholds.

[0058] However, due to the complex operating conditions of the drive motor, the above current setting value is difficult to determine. Setting it too low will waste IGBT module resources, while setting it too high will easily damage the driver module or drive motor. In other words, the above method of setting an upper limit value of current cannot effectively adapt to the complex operating conditions of the drive motor. Furthermore, because temperature values ​​have a hysteresis, the solution of setting an upper limit value of temperature cannot effectively prevent the drive motor from being stalled in a timely manner.

[0059] To address the aforementioned problems, embodiments of the present invention provide a vehicle control method, device, and vehicle.

[0060] Figure 1 This is a schematic diagram of a vehicle control method provided in an embodiment of the present invention, including steps 101 to 103.

[0061] The vehicle control method provided in this embodiment of the invention is suitable for vehicles with a drive motor, specifically a three-phase AC permanent magnet synchronous drive motor, and the vehicle can be a hybrid vehicle or a pure electric vehicle.

[0062] Step 101: Collect the target operating current of at least one phase of the vehicle drive motor.

[0063] In this step, the current flowing through the drive motor coil is directly collected by the drive motor controller as the target operating current, or the target operating current is calculated by collecting the magnetic field strength of the drive motor coil.

[0064] Step 102: Integrate the target operating current according to its magnitude and direction to obtain the integrated current value.

[0065] In this step, the positive and negative directions of the current are predetermined, and then the target operating current is integrated over time to obtain the aforementioned current integral value.

[0066] Optionally, in one embodiment, step 102 specifically includes: if the target operating current does not change direction within a first preset time period, and the target operating current is greater than a preset current threshold, then the target operating current is integrated.

[0067] In this step, the aforementioned first preset duration is the duration during which the current fails to change direction due to a stall in the drive motor. Specifically, it can be the time interval for acquiring the current, that is, comparing the currently acquired operating current with the previously acquired operating current. The direction of the operating current is determined by whether the two directions are the same. If they are the same, the direction has not changed; if they are different, the direction has changed. In practical applications, the direction can be determined by whether the product of the currently acquired operating current and the previously acquired operating current is less than or equal to 0. If the product is less than or equal to 0, the directions are different; if the product is greater than 0, the directions are the same.

[0068] In this step, the aforementioned current threshold is the current value used to determine whether the drive motor is stalled. Because the direction of the current in each phase of the drive motor continuously changes when it rotates, if the current direction no longer changes, it indicates that a stall may have occurred. At the same time, because the current in the drive motor controller increases sharply after the drive motor stalls, if the current direction no longer changes and the operating current is greater than the aforementioned current threshold, the drive motor is very likely to have a stall fault. Therefore, the operating current is integrated to further determine whether the drive motor has stalled.

[0069] Step 103: If the current integral value meets the preset stall condition, then control the drive motor to enter the stall working mode.

[0070] In this step, when the drive motor stalls, the current in the drive motor controller increases sharply, causing heat generation. The amount of heat generated is directly related to the cumulative current value. The stall condition mentioned above is related to the integral value of the current and is used to determine whether the drive motor is about to enter a stall state. Therefore, when the integral value of the current meets the stall condition, it indicates that the drive motor has a risk of stalling, and thus it is controlled to enter the stall working mode. This stall working mode is a working mode that prevents the drive motor from being burned out due to stalling.

[0071] Optionally, in one embodiment, the vehicle control method provided by the present invention further includes step 104 after the drive motor enters the stall mode:

[0072] When the speed of the drive motor is greater than the upper limit of the stall speed and the duration is greater than or equal to the second preset duration, the drive motor is controlled to exit the stall working mode;

[0073] The upper limit of the stall speed is the upper limit of the speed of the drive motor when it is in a stall state.

[0074] In this step, the upper limit of the stall speed is the speed value of the drive motor that determines whether the drive motor is stalled; the second preset duration is the duration for the drive motor to get out of the stall state.

[0075] In this embodiment, after determining that the drive motor is stalled, the drive motor speed is continuously monitored. If the absolute value of the drive motor speed is greater than the upper limit of the stalled speed and the duration is greater than or equal to the second preset duration, it indicates that the drive motor has resumed rotation. Therefore, the stall fault code is cleared, the stall trigger count is reset to zero, and then the stall protection for the drive motor is stopped.

[0076] This invention continuously collects the target operating current of at least one phase of the vehicle's drive motor; based on the magnitude and direction of the target operating current, it integrates the target operating current to obtain an integral value; if the integral value meets a preset stall condition, the drive motor is controlled to enter a stall operating mode. Because the current values ​​of each phase of the drive motor have high real-time performance, integrating the current direction and value of each phase dynamically determines stall faults, greatly improving the stall fault detection rate and thus providing rapid and effective stall protection for the drive motor.

[0077] Optionally, in one embodiment, the above-mentioned current integral value satisfies a preset stall condition, including steps 301 to 303:

[0078] Step 301: Obtain the current integration threshold.

[0079] In this step, the current integral threshold is the current integral value that determines whether the drive motor is stalled. This value is related to the performance and state of the drive motor, so it needs to be obtained in advance.

[0080] Step 302: When the current integral value is greater than the current integral threshold, a counting is triggered.

[0081] Therefore, if the current integral value is continuously greater than the aforementioned current integral threshold, even if the actual temperature of the drive motor has not risen to the upper limit of temperature that would damage the drive motor, it can be determined that the drive motor may experience a stall fault. However, in order to avoid accidental events or monitoring errors, events where the current integral value is greater than the current integral threshold are counted to determine whether they are accidental events.

[0082] Step 303: If the number of consecutive trigger counts reaches the preset count threshold, the stall condition is satisfied.

[0083] In this step, the counting threshold is used to determine whether the current integral value being greater than the current integral threshold is an accidental event. If the current integral value is greater than the current integral threshold for a continuous number of times, that is, the current integral value is continuously greater than the current integral threshold and it is not an accidental event, it can be determined that the drive motor is stalled, that is, the stall condition is met.

[0084] In the above implementation, the target operating current is integrated and the integrated current value is compared with the integrated current threshold. Then, when the number of triggers where the integrated current value is greater than the integrated current threshold reaches the counting threshold, the drive motor is determined to be stalled and controlled to enter the stalled working mode. This can effectively reduce misjudgments caused by accidental events and provide early stall protection for the drive motor, thereby solving the temperature hysteresis problem, achieving efficient identification of drive motor stall faults, and avoiding damage to the drive motor or even traffic accidents caused by stalling.

[0085] Optionally, in the above embodiments, when comparing the current integral value with the current integral threshold, if the current integral value is greater than the current integral threshold and the number of stall triggers has not reached the stall trigger count threshold, then the stall trigger count is incremented by 1 and the stall current integral value is cleared to zero; if the number of stall triggers is greater than or equal to the upper limit of the stall trigger count, then a stall fault is triggered.

[0086] In this embodiment of the invention, for the U-phase current, V-phase current and W-phase current in a three-phase AC permanent magnet synchronous drive motor, as long as any phase current does not change direction within a preset time period, and the current is greater than the current threshold, and the current integral value is continuously greater than the current integral threshold, the drive motor is determined to be stalled and stall protection is performed.

[0087] For example, regarding the U-phase current of a three-phase AC permanent magnet synchronous drive motor, the execution flow of the vehicle control method provided in this embodiment of the invention is as follows:

[0088] Determine whether the current U-phase current IuRms and the previous U-phase current IuRmsPre are in the same direction;

[0089] If IuRms*IuRmsPre is less than or equal to 0, then the current is determined to be in opposite directions, and the stall current integral IurmsStallSum is set to 0, and the stall trigger count IurmsStallCount is set to 0.

[0090] If (IuRms*IuRmsPre>0), then determine that the currents are in the same direction, and then determine the magnitude of the U-phase current IuRms;

[0091] If the phase current IuRms is less than or equal to the stall current limit IrmsUvwStallThreshold, then determine the stall trigger count IurmsStallCount.

[0092] If the number of stall triggers IurmsStallCount is greater than or equal to the upper limit of the number of triggers IurmsStallCount1, then a stall fault (StallFault=1) is triggered; if the phase current IuRms is greater than the stall current limit IrmsUvwStallThreshold, then the U phase current value IuRms is accumulated as the stall current integral value IurmsStallSum.

[0093] If the stall current integral value IurmsStallSum is greater than the stall current integral upper limit value IurmsStallSum1, then the stall trigger count IurmsStallSum is incremented by 1 and the stall current integral value IurmsStallSum is cleared to zero.

[0094] If the stall current integral value IurmsStallSum is less than or equal to the upper limit value IurmsStallSum1, and the stall trigger count IurmsStallCount is greater than or equal to the upper limit value IurmsStallCount1, then a stall fault (StallFault = 1) is triggered.

[0095] If the current absolute speed value SpeedFact is greater than the stall speed limit value SpeedFact1 and the duration is greater than or equal to the count limit value StallCount1, then the stall fault is cleared (StallFault = 0).

[0096] For example, regarding the V-phase current of a three-phase AC permanent magnet synchronous drive motor, the execution flow of the vehicle control method provided in this embodiment of the invention is as follows:

[0097] Determine whether the current V-phase current IvRms and the previous V-phase current IvRmsPre are in the same direction;

[0098] If IvRms*IvRmsPre is less than or equal to 0, then the current is determined to be in opposite directions, and the stall current integral IvrmsStallSum is set to 0, and the stall trigger count IvrmsStallCount is set to 0.

[0099] If (IvRms*IvRmsPre>0), then determine that the currents are in the same direction, and then determine the magnitude of the V-phase current IvRms;

[0100] If the phase current IvRms is less than or equal to the stall current limit IrmsUvwStallThreshold, then determine the stall trigger count IvrmsStallCount.

[0101] If the number of stall triggers IvrmsStallCount is greater than or equal to the upper limit of the number of triggers IvrmsStallCount1, then a stall fault (StallFault=1) is triggered; if the phase current IvRms is greater than the stall current limit IrmsUvwStallThreshold, then the accumulated V phase current value IvRms is used as the stall current integral value IvrmsStallSum.

[0102] If the stall current integral value IvrmsStallSum is greater than the stall current integral upper limit value IvrmsStallSum1, then the stall trigger count IvrmsStallSum is incremented by 1 and the stall current integral value IvrmsStallSum is cleared to zero.

[0103] If the stall current integral value IvrmsStallSum is less than or equal to the upper limit value IvrmsStallSum1, and the stall trigger count IvrmsStallCount is greater than or equal to the upper limit value IvrmsStallCount1, then a stall fault (StallFault = 1) is triggered.

[0104] If the current absolute speed value SpeedFact is greater than the stall speed limit value SpeedFact1 and the duration is greater than or equal to the count limit value StallCount1, then the stall fault is cleared (StallFault = 0).

[0105] For example, regarding the W-phase current of a three-phase AC permanent magnet synchronous drive motor, the execution flow of the vehicle control method provided in this embodiment of the invention is as follows:

[0106] Determine whether the current W-phase current IwRms and the previous W-phase current IwRmsPre are in the same direction;

[0107] If IwRms*IwRmsPre is less than or equal to 0, then the current is determined to be in opposite directions, and the stall current integral IwrmsStallSum is set to 0, and the stall trigger count IwrmsStallCount is set to 0.

[0108] If (IwRms*IwRmsPre>0), then determine that the currents are in the same direction, and then determine the magnitude of the W-phase current IwRms;

[0109] If the phase current IwRms is less than or equal to the stall current limit IrmsUvwStallThreshold, then determine the stall trigger count IwrmsStallCount.

[0110] If the number of stall triggers IwrmsStallCount is greater than or equal to the upper limit of the number of triggers IwrmsStallCount1, then a stall fault (StallFault=1) is triggered; if the phase current IwRms is greater than the stall current limit IrmsUvwStallThreshold, then the phase current value IwRms is accumulated as the stall current integral value IwrmsStallSum.

[0111] If the stall current integral value IwrmsStallSum is greater than the stall current integral upper limit value IwrmsStallSum1, then the stall trigger count IwrmsStallSum is incremented by 1 and the stall current integral value IwrmsStallSum is cleared to zero.

[0112] If the stall current integral value IwrmsStallSum is less than or equal to the stall current integral upper limit value IwrmsStallSum1, and the stall trigger count IwrmsStallCount is greater than or equal to the trigger count upper limit value IwrmsStallCount1, then a stall fault (StallFault=1) is triggered.

[0113] If the current absolute speed value SpeedFact is greater than the stall speed limit value SpeedFact1 and the duration is greater than or equal to the count limit value StallCount1, then the stall fault is cleared (StallFault = 0).

[0114] Optionally, in one embodiment, the vehicle control method provided by the present invention includes steps 3011 to 3012 in step 301 above:

[0115] Step 3011: Obtain the first actual temperature of the power transistor, the stall carrier frequency, the stall current limit, and the second actual temperature of the drive motor; the power transistor is electrically connected to the drive motor and is used to invert the DC power output from the power supply into AC power before sending it to the drive motor.

[0116] In this step, while the drive motor is running, the actual temperature of the power transistor (IGBT), carrier frequency, and stall current limit in the drive motor controller are continuously acquired, as well as the actual temperature of the drive motor.

[0117] The aforementioned locked-rotor current limit is the upper limit of the current that the power transistor can withstand.

[0118] Step 3012: Determine the current integration threshold based on the first actual temperature, the stall current limit, the second actual temperature, and the stall carrier frequency.

[0119] In this step, the duration of the power transistor's tolerance to temperature rise caused by stalling is related to its actual temperature and stall current limit. Specifically, because the power transistor does not commutate when the drive motor is stalled, it experiences overcurrent, heat, and eventually burns out. The lower the actual temperature of the power transistor, the longer its tolerance to temperature rise caused by stalling. Simultaneously, the duration of the drive motor's tolerance to temperature rise caused by stalling is related to its actual temperature and stall carrier frequency. The higher the carrier frequency, the less vibration and heat generated by the drive motor, resulting in a slower temperature rise rate and a longer tolerance to temperature rise caused by stalling. Conversely, the higher the actual temperature of the drive motor, the faster it reaches its high-temperature tolerance limit, and the shorter its tolerance to temperature rise caused by stalling. And the lower the actual temperature of the drive motor, the slower it reaches its high-temperature tolerance limit, and the longer its tolerance to temperature rise caused by stalling.

[0120] In this embodiment, since a stalled drive motor can cause overheating and damage to the power transistor and the drive motor, when determining the current integration threshold for judging a stall fault, it is necessary to consider the actual temperature of the power transistor, the carrier frequency, the stall current limit, and the actual temperature of the drive motor. That is, the current integration threshold is determined by the actual temperature of the power transistor, the carrier frequency, the actual temperature of the drive motor, and the stall current limit. This allows for more accurate judgment of potential stall faults and more efficient stall protection for the drive motor.

[0121] Optionally, in one specific embodiment, step 3012 above includes steps 3201 to 3203.

[0122] Step 3201: Determine the first temperature coefficient of the power transistor based on the first actual temperature, the upper limit of the first temperature that the power transistor can withstand, and the lower limit of the first temperature.

[0123] In this step, the upper limit of the first temperature and the lower limit of the first temperature that the power transistor can withstand reflect its temperature tolerance performance, while the first actual temperature reflects its current temperature state. The increase in its temperature is mainly caused by excessive overcurrent. Therefore, the parameters for adjusting its current tolerance performance can be determined by combining the three, which is the aforementioned first temperature coefficient.

[0124] In practical applications, the full-scale coefficient of the IGBT temperature coefficient is set to 0.1000‰, that is, the upper limit of the first temperature coefficient is 1000‰ and the lower limit of the first temperature coefficient is 0. If the first actual temperature is less than the lower limit of the first temperature coefficient, the first temperature coefficient is assigned to the upper limit of the first temperature coefficient. If the first actual temperature is greater than the upper limit of the first temperature coefficient, the first temperature coefficient is assigned to the lower limit of the first temperature coefficient. If the first actual temperature is between the lower limit of the first temperature coefficient and the upper limit of the first temperature coefficient, the first temperature coefficient is dynamically calculated according to the formula first temperature coefficient = (1000 - kCoef1 * (first actual temperature - lower limit of the first temperature coefficient)). Among them, kCoef1 is a constant related to the heat resistance performance of the power transistor, which is specifically determined through experiments.

[0125] Step 3202: Determine the second temperature coefficient of the drive motor based on the second actual temperature, the upper limit of the second temperature that the drive motor can withstand, and the lower limit of the second temperature.

[0126] In this step, the first upper temperature limit and the first lower temperature limit of the drive motor reflect its temperature tolerance performance, while the second actual temperature reflects its current temperature state. The temperature rise is mainly caused by excessive overcurrent. Therefore, the parameters for adjusting the current tolerance performance of the drive motor can be determined by combining the three, which is the second temperature coefficient mentioned above.

[0127] In practical applications, the full-scale coefficient of the drive motor temperature coefficient is set to 0.1000‰, meaning the upper limit of the second temperature coefficient is 1000‰ and the lower limit is 0. If the second actual temperature is less than the lower limit of the second temperature coefficient, the upper limit of the second temperature coefficient is assigned. If the second actual temperature is greater than the upper limit of the second temperature coefficient, the lower limit of the second temperature coefficient is assigned. If the second actual temperature is between the lower limit and the upper limit of the second temperature coefficient, the second temperature coefficient is dynamically calculated according to the formula: second temperature coefficient = (1000 - kCoef2 * (second actual temperature - lower limit of the second temperature coefficient)). Here, kCoef2 is a constant related to the heat resistance performance of the drive motor, which is specifically determined through experiments.

[0128] Step 3203: Determine the current integration threshold based on the product of the first temperature coefficient, the second temperature coefficient, the stall current limit, and the stall carrier frequency.

[0129] In this step, since the drive system's tolerance to the temperature rise caused by the drive motor being stalled is positively correlated with the first temperature coefficient, the second temperature coefficient, the stall current limit, and the stall carrier frequency, the current integration threshold can be determined based on the product of these four parameters. Specifically, the product of the first temperature coefficient / amplification factor, the second temperature coefficient / second amplification factor, the stall current limit, and the stall carrier frequency of the power transistor is used as the current integration threshold.

[0130] For example, the above current integral threshold is calculated using the formula ((1000-kCoef1*(first actual temperature-first lower limit value)) / 1000)*((1000-kCoef2*(second actual temperature-second lower limit value)) / 1000)*locked rotor current limit*locked rotor carrier frequency.

[0131] In this specific embodiment, the actual temperature of the power transistor, the carrier frequency, the actual temperature of the drive motor, and the stall current limit are comprehensively considered to jointly determine the current integral threshold for determining the stall of the drive motor. At the same time, the overheating of the power transistor and the drive motor is also taken into account. Therefore, the current integral threshold can effectively predict the stall fault of the drive motor and avoid overheating damage to the power transistor of the drive motor and the electric drive system.

[0132] Optionally, in one embodiment, the above-mentioned control of the drive motor to enter a stalled operating mode includes at least one of the following:

[0133] A stall alarm is generated based on the stall status of the drive motor;

[0134] Increase the cooling intensity of the drive motor;

[0135] The drive motor is protected against stall.

[0136] In this embodiment, a stall alarm for the drive motor can remind the driver of the drive motor status, enabling timely correction of erroneous or unreasonable driving behaviors and preventing further damage to the drive motor. Increasing the cooling intensity of the drive motor can slow down the rate of temperature rise, which can specifically include increasing the coolant flow through the drive motor and increasing the fan speed. Stall protection for the drive motor actively protects the drive motor from being burned out by high temperatures.

[0137] Optionally, in one specific embodiment, the drive motor is protected against stall, including steps 303 to 304:

[0138] Step 303: Calculate the stall torque required for the vehicle.

[0139] In this step, since the drive motor is usually locked on steep slopes, the vehicle is prone to rolling backward after the drive motor is locked. If the driver does not react in time or makes an incorrect driving action due to panic, it will lead to a safety accident. Therefore, it is necessary to calculate the torque required to prevent the vehicle from rolling backward, that is, the locked torque mentioned above, in order to control the torque output of the drive motor and prevent the vehicle from rolling backward.

[0140] Optionally, in one specific embodiment, calculating the stall torque required for the vehicle includes: obtaining the vehicle's mass, tilt angle, speed ratio coefficient, and gravitational acceleration; and determining the stall torque by calculating mass * gravitational acceleration * Sin(tilt angle) / speed ratio coefficient.

[0141] In this specific implementation, since the vehicle rolls backward on the slope due to the force of gravity, the stall torque required to overcome the force of gravity can be calculated by using the vehicle's mass, horizontal tilt angle, speed ratio coefficient, and gravitational acceleration, according to the formula mass * gravitational acceleration * Sin(horizontal tilt angle) / speed ratio coefficient. The vehicle can then output power based on this stall torque to prevent it from rolling backward and ensure the safety of the occupants.

[0142] Step 304: Based on the peak torque of the drive motor, the stall torque, and the target torque, control the drive motor to output the actual torque.

[0143] In this step, the peak torque is the upper limit of the torque that the drive motor can output, while the target torque is the torque triggered when the driver presses the accelerator or gas pedal, which is the torque that the user wants the drive motor to output.

[0144] In this step, based on the aforementioned peak torque, stall torque, and target torque, the drive motor outputs a specific torque, which can effectively balance the user's actual driving needs and prevent the vehicle from rolling backward, while avoiding damage to the drive motor due to stall.

[0145] Optionally, in one specific embodiment, step 304 above includes steps 3041 to 3043:

[0146] Step 3041: If the stall torque is greater than the peak torque, set the stall torque to the peak torque.

[0147] In this step, since the peak torque is the maximum torque that the drive motor can output, when the stall torque is greater than the peak torque, it means that the torque required to prevent the vehicle from rolling backward has exceeded the upper limit of the drive motor torque. Therefore, in order to avoid damaging the drive motor, the drive motor output is controlled only according to the peak torque.

[0148] Step 3042: When the target torque is greater than the stall torque, control the drive motor to output the actual torque as the target torque.

[0149] In this step, when the target torque is greater than the stall torque mentioned above, it means that the user wants the vehicle to be able to drive away from its current position with a larger torque output. However, in order to avoid further damage to the drive motor, the drive motor output is controlled according to the stall torque. This not only effectively prevents the vehicle from rolling backward, but also avoids damage to the drive motor and power transistors caused by the user's incorrect operation.

[0150] Step 3043: When the target torque is less than or equal to the stall torque, control the drive motor to output the actual torque as the stall torque.

[0151] In this step, when the target torque is less than or equal to the stall torque mentioned above, it indicates that the torque demand triggered by the user is too small and there is a need to control the vehicle to roll backward. Therefore, controlling the output of the drive motor according to the stall torque can not only avoid damage to the electric drive system, but also meet the actual torque demand required by the user.

[0152] In the above specific implementation, by taking into account the peak torque of the drive motor, the stall torque required to resist the vehicle rolling backward, and the user's target torque, the drive motor outputs a specific torque. This can effectively balance the user's actual driving needs and prevent the vehicle from rolling backward, while avoiding damage to the drive motor due to stalling.

[0153] Figure 2 This is a schematic diagram of a vehicle control device provided in an embodiment of the present invention. The device includes:

[0154] The acquisition module 21 is used to acquire the target operating current of at least one phase of the vehicle drive motor;

[0155] The integration module 22 is used to integrate the target operating current according to the magnitude and direction of the target operating current to obtain the current integral value;

[0156] The control module 23 is used to control the drive motor to enter the stall working mode if the current integral value meets the preset stall condition.

[0157] Optionally, in the control device, the integration module 22 is specifically used to integrate the target operating current if the target operating current does not change direction within a first preset time period and the target operating current is greater than a preset current threshold.

[0158] Optionally, in the control device, the control module 23 includes:

[0159] The acquisition submodule is used to obtain the current integration threshold;

[0160] The counting submodule is used to trigger counting when the integral value of the current is greater than the integral threshold value of the current.

[0161] The determination submodule is used to satisfy the stall condition if the number of consecutive trigger counts reaches a preset count threshold.

[0162] Optionally, the acquisition submodule in the control device includes:

[0163] The acquisition unit is used to acquire the first actual temperature of the power transistor, the stall carrier frequency, the stall current limit, and the second actual temperature of the drive motor; the power transistor is electrically connected to the drive motor and is used to invert the DC power output from the power supply into AC power and then send it to the drive motor.

[0164] The determining unit is configured to determine the current integration threshold based on the first actual temperature, the stall current limit, the second actual temperature, and the stall carrier frequency.

[0165] Optionally, in the control device, the determining unit includes:

[0166] The first determining subunit is used to determine the first temperature coefficient of the power transistor based on the first actual temperature, the first upper temperature limit value and the first lower temperature limit value that the power transistor can withstand.

[0167] The second determining subunit is used to determine the second temperature coefficient of the drive motor based on the second actual temperature, the upper limit value of the second temperature that the drive motor can withstand, and the lower limit value of the second temperature.

[0168] The third determining subunit is used to determine the current integration threshold based on the product of the first temperature coefficient, the second temperature coefficient, the stall current limit, and the stall carrier frequency.

[0169] Optionally, in the control device, the control module 23 includes at least one of the following:

[0170] An alarm submodule is used to generate a stall alarm based on the stall status of the drive motor.

[0171] The cooling submodule is used to increase the cooling intensity of the drive motor;

[0172] The stall protection submodule is used to provide stall protection for the drive motor.

[0173] Optionally, the stall protection submodule in the control device includes:

[0174] The calculation unit is used to calculate the stall torque required by the vehicle;

[0175] The control unit is used to control the drive motor to output actual torque based on the peak torque of the drive motor, the stall torque, and the target torque, wherein the peak torque is the upper limit of the torque output by the drive motor, and the target torque is the torque determined according to the throttle position.

[0176] Optionally, in the control device, the computing unit includes:

[0177] The acquisition sub-unit is used to acquire the vehicle's mass, horizontal tilt angle, speed ratio coefficient, and gravitational acceleration.

[0178] The fourth determination subunit is used to determine the stall torque according to mass * gravitational acceleration * Sin (horizontal tilt angle) / speed ratio coefficient.

[0179] Optionally, in the control device, the control unit includes:

[0180] A subunit is configured to set the stall torque to the peak torque when the stall torque is greater than the peak torque.

[0181] The first control subunit is configured to control the drive motor to output an actual torque equal to the stall torque when the target torque is greater than the stall torque.

[0182] The second control subunit is used to control the drive motor to output an actual torque equal to the target torque when the target torque is less than or equal to the stall torque.

[0183] Optionally, in the control device, the control module 23 further includes:

[0184] The exit submodule is used to control the drive motor to exit the stall working mode when the speed of the drive motor is greater than the upper limit of the stall speed and the duration is greater than or equal to the second preset duration.

[0185] The upper limit of the stall speed is the upper limit of the speed of the drive motor when it is in a stall state.

[0186] This invention also provides a vehicle, which is an electric vehicle, and the vehicle includes the vehicle control device as described above.

[0187] For the above-described device and vehicle embodiments, since they are basically similar to the vehicle control method embodiments, the relevant parts can be referred to in the description of the method embodiments.

[0188] The vehicle control device and vehicle provided in this embodiment of the invention continuously collect the operating current of each phase of the drive motor. If the operating current of any phase does not change direction within a preset time period and is greater than a current threshold, the operating current is integrated. If the integrated current value continuously exceeds the current integration threshold, the drive motor is protected against stall. Because the current values ​​of each phase of the drive motor are highly real-time, dynamically determining the stall fault by analyzing the direction and value of the current in each phase greatly improves the stall fault detection rate, thereby enabling rapid and effective stall protection of the drive motor.

[0189] This invention also provides an electronic device, such as... Figure 3 As shown, it includes a processor 31, a communication interface 32, a memory 33, and a communication bus 34, wherein the processor 31, the communication interface 32, and the memory 33 communicate with each other through the communication bus 34.

[0190] Memory 33 is used to store computer programs.

[0191] When processor 31 executes the program stored in memory 33, it performs the following steps:

[0192] Collect the target operating current of at least one phase of the vehicle drive motor;

[0193] Based on the magnitude and direction of the target operating current, the target operating current is integrated to obtain the current integral value;

[0194] If the integral value of the current meets the preset stall condition, the drive motor is controlled to enter the stall working mode.

[0195] The processor 31 can also implement other steps in the above vehicle control method, which will not be described in detail here.

[0196] The communication bus mentioned in the above electronic devices can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus can be divided into address bus, data bus, control bus, etc. For ease of illustration, only one thick line is used to represent it in the diagram, but this does not indicate that there is only one bus or one type of bus.

[0197] The communication interface is used for communication between the aforementioned electronic devices and other devices.

[0198] The memory may include random access memory (RAM) or non-volatile memory, such as at least one disk storage device. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor.

[0199] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0200] In another embodiment of the present invention, a computer-readable storage medium is also provided, which stores instructions that, when executed on a computer, cause the computer to perform the vehicle control method described in the above embodiments.

[0201] In another embodiment of the present invention, a computer program product containing instructions is also provided, which, when run on a computer, causes the computer to execute the vehicle control method described in the above embodiments.

[0202] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present invention are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid state disk (SSD)).

[0203] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0204] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. For embodiments of devices, electronic devices, computer-readable storage media, and computer program products containing instructions, the descriptions are relatively simple because they are basically similar to the method embodiments; relevant parts can be referred to the descriptions of the method embodiments.

[0205] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A vehicle control method, characterized in that, include: Collect the target operating current of at least one phase of the vehicle drive motor; Based on the magnitude and direction of the target operating current, the target operating current is integrated to obtain the current integral value; The first actual temperature of the power transistor, the stall carrier frequency, the stall current limit, and the second actual temperature of the drive motor are obtained. The power transistor is electrically connected to the drive motor and is used to invert the DC power output from the power supply into AC power and then send it to the drive motor. The current integration threshold is determined based on the first actual temperature, the stall current limit, the second actual temperature, and the stall carrier frequency; When the integral value of the current exceeds the integral threshold of the current, counting is triggered. If the number of consecutive trigger counts reaches a preset count threshold, the current integral value is determined to meet the preset stall condition, and the drive motor is controlled to enter the stall working mode.

2. The control method according to claim 1, characterized in that, The step of integrating the target operating current based on its magnitude and direction includes: If the target operating current does not change direction within a first preset time period, and the target operating current is greater than a preset current threshold, then the target operating current is integrated.

3. The control method according to claim 1, characterized in that, The current integration threshold is determined based on the first actual temperature, the locked-rotor current limit, the second actual temperature, and the locked-rotor carrier frequency, including: The first temperature coefficient of the power transistor is determined based on the first actual temperature, the upper limit of the first temperature that the power transistor can withstand, and the lower limit of the first temperature. The second temperature coefficient of the drive motor is determined based on the second actual temperature, the upper limit of the second temperature that the drive motor can withstand, and the lower limit of the second temperature. The current integration threshold is determined based on the product of the first temperature coefficient, the second temperature coefficient, the stall current limit, and the stall carrier frequency.

4. The control method according to claim 1, characterized in that, Controlling the drive motor to enter a stalled operating mode includes at least one of the following: A stall alarm is generated based on the stall status of the drive motor; Increase the cooling intensity of the drive motor; The drive motor is protected against stall.

5. The control method according to claim 4, characterized in that, Stall protection for the drive motor includes: Calculate the stall torque required for the vehicle; Based on the peak torque of the drive motor, the stall torque, and the target torque, the drive motor is controlled to output actual torque, wherein the peak torque is the upper limit of the torque output by the drive motor, and the target torque is the torque determined based on the vehicle accelerator.

6. The control method according to claim 5, characterized in that, Calculate the stall torque required for the vehicle, including: Obtain the vehicle's mass, tilt angle, speed ratio coefficient, and gravitational acceleration; The stall torque is determined by mass * gravitational acceleration * sin(horizontal tilt angle) / speed ratio coefficient.

7. The control method according to claim 5, characterized in that, Based on the peak torque of the drive motor, the stall torque, and the target torque, the actual torque output of the drive motor is controlled, including: When the stall torque is greater than the peak torque, the stall torque is set to the peak torque; When the target torque is greater than the stall torque, the drive motor is controlled to output an actual torque equal to the stall torque. When the target torque is less than or equal to the stall torque, the drive motor is controlled to output the actual torque as the target torque.

8. The control method according to any one of claims 1 to 7, characterized in that, After the drive motor enters the stalled operating mode, the method further includes: When the speed of the drive motor is greater than the upper limit of the stall speed and the duration is greater than or equal to the second preset duration, the drive motor is controlled to exit the stall working mode. The upper limit of the stall speed is the upper limit of the speed of the drive motor when it is in a stall state.

9. A vehicle control device, characterized in that, include: The acquisition module is used to acquire the target operating current of at least one phase of the vehicle drive motor; An integration module is used to integrate the target operating current based on its magnitude and direction to obtain an integral value. The acquisition unit is used to acquire the first actual temperature of the power transistor, the stall carrier frequency, the stall current limit, and the second actual temperature of the drive motor; the power transistor is electrically connected to the drive motor and is used to invert the DC power output from the power supply into AC power and then send it to the drive motor. The determining unit is configured to determine the current integration threshold based on the first actual temperature, the stall current limit, the second actual temperature, and the stall carrier frequency; The counting submodule is used to trigger counting when the integral value of the current is greater than the integral threshold value of the current. The determination submodule is used to determine if the current integral value meets the preset stall condition if the number of consecutive trigger counts reaches a preset count threshold, and then control the drive motor to enter the stall working mode.

10. An electronic device, characterized in that, include: The system includes a processor, a communication interface, a memory, and a communication bus; the processor, communication interface, and memory communicate with each other via the communication bus. Memory, used to store computer programs; A processor, when executing a program stored in memory, implements the steps of the vehicle control method as described in any one of claims 1 to 8.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the steps in the vehicle control method as described in any one of claims 1 to 8.

12. A vehicle, characterized in that, This includes the vehicle control device as described in claim 9 or the electronic device as described in claim 10.

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