A vehicle parking control method and device based on an induction motor and a vehicle

Abstract

The application discloses a vehicle parking control method and device based on an induction motor and a vehicle. The method comprises the following steps: after the accelerator of the vehicle is released, it is judged whether the motor meets preset conditions; if the motor meets the preset conditions, the feedback speed of the motor is controlled to be zero, and the output of the field weakening regulator is turned off; otherwise, the target speed of the motor is reduced according to a preset deceleration, and the feedback speed of the motor is controlled to be the actual speed of the motor; a first output value of a speed control strategy is determined according to the target speed and the feedback speed; a second output value of a first current control strategy is determined according to the first output value; a fourth output value of a second current control strategy is determined according to the first output value and a third output value of the field weakening regulator; the motor is controlled to operate according to the second output value and the fourth output value, and the step of judging whether the motor meets the preset conditions is executed again. The technical scheme can better control the vehicle parking.

Description

Technical Field

[0001] This invention relates to the field of vehicle control technology, and in particular to a vehicle parking control method, device, and vehicle based on an induction motor. Background Technology

[0002] With the rapid rise of new energy sources and the rapid development of technologies such as battery energy storage, the proportion of electric vehicles has increased dramatically.

[0003] With the increasing popularity of electric vehicles, drivers have higher and higher demands for them, not only in terms of performance, quality, and energy consumption, but also in terms of overall driving comfort. Unlike in the past, most vehicle manufacturers now require vehicles to decelerate and stop smoothly on slopes after the accelerator is released, without the need for a brake pedal. The motor's torque should maintain the vehicle's stability on the slope, and it should not roll back after stopping on flat ground. However, existing vehicle control strategies are not effective at controlling vehicle stopping, resulting in a poor driving experience. Summary of the Invention

[0004] This invention provides a vehicle parking control method, device, and vehicle based on an induction motor to solve the problem that existing vehicle control strategies cannot effectively control vehicle parking, resulting in a poor driving experience.

[0005] According to one aspect of the present invention, a vehicle parking control method based on an induction motor is provided, the vehicle parking control method based on an induction motor comprising:

[0006] After the vehicle's accelerator is released, it is determined whether the motor meets the preset conditions; wherein, the motor meets the preset conditions if the actual speed of the motor is greater than zero and the duration of the maintenance of the first threshold is greater than the first preset duration, and the target speed of the motor is zero.

[0007] If the motor meets the preset conditions, the feedback speed of the motor is controlled to be zero and the output of the field weakening regulator is turned off; otherwise, the target speed of the motor is reduced according to the preset deceleration and the feedback speed of the motor is controlled to be the actual speed of the motor.

[0008] The first output value of the speed control strategy corresponding to the current speed control cycle is determined based on the target speed and the feedback speed of the motor; wherein, the speed control strategy includes a speed proportional term and a speed integral term;

[0009] The second output value of the first current control strategy corresponding to the current speed control cycle is determined based on the first output value corresponding to the current speed control cycle; wherein, the first current control strategy includes a first current proportional term and a first current integral term;

[0010] The fourth output value of the second current control strategy corresponding to the current speed control cycle is determined based on the first output value corresponding to the current speed control cycle and the third output value of the field weakening regulator. The motor is then controlled to run based on the second output value and the fourth output value. The process then returns to the step of determining whether the motor meets the preset conditions. The second current control strategy includes a second current proportional term and a second current integral term.

[0011] Optionally, determining the first output value of the speed control strategy corresponding to the current speed control cycle based on the target speed and the feedback speed of the motor in the current speed control cycle includes:

[0012] The product of the difference between the target speed corresponding to the current speed control cycle and the feedback speed of the motor, and the speed proportional coefficient, is used as the speed proportional term of the speed control strategy.

[0013] The product of the proportional speed term and the integral speed coefficient corresponding to the current speed control cycle is added to the integral speed term corresponding to the previous speed control cycle to obtain the integral speed term corresponding to the current speed control cycle.

[0014] The sum of the proportional and integral terms of the speed corresponding to the current speed control cycle is used as the first output value corresponding to the current speed control cycle.

[0015] Optionally, determining the second output value of the first current control strategy corresponding to the current speed control cycle based on the first output value corresponding to the current speed control cycle includes:

[0016] The product of the difference between the first output value and the first actual current of the motor corresponding to the current speed control cycle and the first current proportional coefficient is used as the first current proportional term corresponding to the current speed control cycle.

[0017] The product of the first current proportional term and the first current integral coefficient corresponding to the current speed control cycle is added to the first current integral term corresponding to the previous speed control cycle to obtain the first current integral term corresponding to the current speed control cycle.

[0018] The sum of the first proportional term and the first integral term of the current speed control cycle is used as the second output value corresponding to the current speed control cycle.

[0019] Optionally, determining the fourth output value of the second current control strategy corresponding to the current speed control cycle based on the first output value corresponding to the current speed control cycle and the third output value of the field weakening regulator includes:

[0020] The second target current of the second current control strategy corresponding to the current speed control cycle is determined by the sum of the product of the first output value and the preset coefficient corresponding to the current speed control cycle and the third output value of the field weakening regulator.

[0021] The product of the difference between the second target current and the second actual current of the motor corresponding to the current speed control cycle and the second current proportional coefficient is used as the second current proportional term corresponding to the current speed control cycle.

[0022] The product of the second current proportional term and the second current integral coefficient corresponding to the current speed control cycle is added to the second current integral term corresponding to the previous speed control cycle to obtain the second current integral term corresponding to the current speed control cycle.

[0023] The sum of the second current proportional term and the second current integral term corresponding to the current speed control cycle is taken as the fourth output value corresponding to the current speed control cycle.

[0024] Optionally, after controlling the feedback speed of the motor to zero and turning off the output of the field weakening regulator, before determining the first output value of the speed control strategy corresponding to the current speed control cycle based on the target speed and the feedback speed of the motor, the method further includes:

[0025] If the actual speed of the motor is greater than the second threshold, or if the duration for which the actual speed of the motor is not zero is greater than the second preset duration, then the feedback speed of the motor is controlled to be the actual speed of the motor.

[0026] Optionally, determining the second target current of the second current control strategy corresponding to the current speed control cycle by summing the product of the first output value corresponding to the current speed control cycle and a preset coefficient with the third output value of the field weakening regulator includes:

[0027] The product of the first output value corresponding to the current speed control cycle and the preset coefficient, and the sum of the third output value of the field weakening regulator, are used as the initial target current.

[0028] If the initial target current is greater than or equal to the first current threshold, then the initial target current is set to the second target current of the second current control strategy corresponding to the current speed control cycle;

[0029] If the initial target current is less than the first current threshold, then the first current threshold is set to the second target current of the second current control strategy corresponding to the current speed control cycle.

[0030] Optionally, after determining the first output value of the speed control strategy corresponding to the current speed control cycle based on the target speed and the feedback speed of the motor, the method further includes:

[0031] If the duration of the first output value being less than the second current threshold is greater than the third preset duration, then the outputs of the speed control strategy, the first current control strategy, and the second current control strategy are turned off.

[0032] Optionally, after controlling the feedback speed of the motor to zero and turning off the output of the field weakening regulator, the method further includes:

[0033] If a braking signal is received, the speed integral term of the speed control strategy is gradually reduced to zero according to a preset number of times.

[0034] According to another aspect of the present invention, a vehicle parking control device based on an induction motor is provided, the vehicle parking control device based on an induction motor comprising:

[0035] The parameter control module is used to determine whether the motor meets preset conditions after the vehicle's accelerator is released. If the motor meets the preset conditions, the module controls the feedback speed of the motor to be zero and shuts off the output of the field weakening regulator. Otherwise, the module reduces the target speed of the motor according to a preset deceleration and controls the feedback speed of the motor to be the actual speed of the motor. The preset conditions are met when the actual speed of the motor is greater than zero and less than a first threshold for a duration greater than a first preset duration, and the target speed of the motor is zero.

[0036] The speed control module is used to determine the first output value of the speed control strategy corresponding to the current speed control cycle based on the target speed and the feedback speed of the motor; wherein, the speed control strategy includes a speed proportional term and a speed integral term;

[0037] The first current control module is used to determine the second output value of the first current control strategy corresponding to the current speed control cycle based on the first output value corresponding to the current speed control cycle; wherein, the first current control strategy includes a first current proportional term and a first current integral term;

[0038] The second current control module is used to determine the fourth output value of the second current control strategy corresponding to the current speed control cycle based on the first output value corresponding to the current speed control cycle and the third output value of the field weakening regulator, and to control the motor operation based on the second output value and the fourth output value; wherein, the second current control strategy includes a second current proportional term and a second current integral term.

[0039] According to another aspect of the present invention, a vehicle is provided that includes a vehicle parking control device based on an induction motor as described in any embodiment of the present invention.

[0040] The technical solution of this invention, after the accelerator of the vehicle is released, when the actual speed of the motor is greater than a first threshold or the target speed is greater than zero, reduces the target speed of the motor according to a preset deceleration, and controls the feedback speed of the motor to be the actual speed of the motor. This allows the speed control strategy to periodically determine a first output value based on the deviation between the target speed and the actual speed, i.e., to determine the first target current of the first current control strategy. This causes the second output value of the first current control strategy and the fourth output value of the second current control strategy to change with the deviation between the target speed and the actual speed. Thus, the motor operation is controlled according to the second and fourth output values, allowing the motor speed to follow the target speed change. As the target speed gradually decreases (periodically decreases), the motor speed also gradually decreases (periodically decreases). When the actual speed of the motor is greater than zero and less than the first threshold, and the target speed is zero, it indicates that the actual speed of the motor is small, close to 0. Since there is an error in the acquisition of the actual speed of the motor, and the duration of the actual speed of the motor being close to 0 (greater than zero and less than the first threshold) has exceeded the first preset duration, it indicates that the vehicle has reached equilibrium, that is, the torque provided by the motor and the external forces (friction and gravity, etc.) acting on the vehicle have reached equilibrium, indicating that the vehicle has stopped. The feedback speed of the control motor is set to zero, ensuring zero deviation between the target speed and the feedback speed. This results in a zero proportional term for the speed and no further accumulation of the integral term. The first output value of the speed control strategy remains constant, meaning the first target current remains constant. The second output value of the first current control strategy follows the first target current, making the second output value tend to be constant. Furthermore, the output of the field weakener is turned off, meaning the third output value of the field weakener is zero. The second target current also remains constant, making the fourth output value tend to be constant. Since both the third and fourth output values ​​remain constant, the motor operation is controlled based on these values, ensuring a constant output torque and allowing the vehicle to stop stably. This avoids situations where the actual motor speed is greater than zero but less than the first threshold, and the target speed is zero, and the first output value is still adjusted according to the actual motor speed. This would prevent the second and fourth output values ​​from constantly changing, causing the motor speed to fluctuate around zero, potentially leading to vehicle rollback or slippage. This ensures stable vehicle stopping, improves vehicle parking control, and enhances the driving experience.

[0041] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a flowchart of a vehicle parking control method based on an induction motor provided in an embodiment of the present invention;

[0044] Figure 2 This is a flowchart of another vehicle parking control method based on an induction motor provided in an embodiment of the present invention;

[0045] Figure 3 This is a flowchart of another vehicle parking control method based on an induction motor provided in an embodiment of the present invention;

[0046] Figure 4 This is a schematic diagram of a vehicle parking control device based on an induction motor provided in an embodiment of the present invention. Detailed Implementation

[0047] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0048] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0049] This invention provides a vehicle parking control method based on an induction motor, wherein the vehicle includes an induction motor. The induction motor-based vehicle parking control method can be executed by an induction motor-based vehicle parking control device. The vehicle may include an electric vehicle, which can be an electric industrial vehicle, such as an electric forklift.

[0050] Figure 1 This is a flowchart of a vehicle parking control method based on an induction motor provided in an embodiment of the present invention, referred to as... Figure 1 Vehicle parking control methods based on induction motors include:

[0051] S101. After the vehicle's accelerator is released, determine whether the motor meets the preset conditions. If not, proceed to step S102; if yes, proceed to step S103. Wherein, the motor meets the preset conditions as follows: the actual speed of the motor is greater than zero and the duration of the maintenance of the first threshold is greater than the first preset duration, and the target speed of the motor is zero.

[0052] The accelerator in a vehicle is the accelerator pedal. When the accelerator is pressed, the vehicle accelerates or moves at a constant speed. When the accelerator is released, the vehicle decelerates to zero, bringing it to a stop without the need for a brake pedal.

[0053] After the vehicle's accelerator is released, steps S101 to S106 are executed in each speed control cycle. That is, after the vehicle's accelerator is released, steps S101 to S106 are executed cyclically to gradually decelerate the vehicle's motor, thereby reducing the motor speed to zero and stopping the vehicle.

[0054] Specifically, after the vehicle's accelerator is released, it is determined whether the motor meets the preset conditions, that is, whether the duration for which the actual speed of the motor is greater than zero and less than the first threshold is greater than the first preset duration, and whether the target speed of the motor is zero.

[0055] After the vehicle's accelerator is released, before the target speed reaches zero, the target speed is determined once in each speed control cycle. For example, the target speed is gradually reduced by using a preset deceleration, so that the motor can be controlled to run according to the corresponding target speed in each speed control cycle. This ensures that after each speed control cycle, the actual speed of the motor is close to the corresponding target speed, thereby causing the motor speed to gradually decrease.

[0056] The first threshold is a rotational speed close to 0. If the duration for which the motor's actual rotational speed is greater than zero and less than the first threshold exceeds a first preset duration, and the target rotational speed of the motor is zero, it indicates that the motor's actual rotational speed is low, close to 0. Since there are errors in the acquisition of the motor's actual rotational speed, and the duration for which the motor's actual rotational speed is close to 0 (greater than zero and less than the first threshold) exceeds the first preset duration, it indicates that the vehicle has reached equilibrium. That is, the torque provided by the motor and the external forces acting on the vehicle (forces other than the torque provided by the motor, such as friction and gravity) have reached equilibrium, indicating that the vehicle has stopped. If the duration for which the motor's actual rotational speed is greater than zero and less than the first threshold does not reach the first preset duration, or if the target rotational speed of the motor is not zero, it indicates that the motor's rotational speed is too high, and further deceleration is required.

[0057] S102. Reduce the target speed of the motor according to the preset deceleration, and control the feedback speed of the motor to be the actual speed of the motor.

[0058] Specifically, if the motor does not meet the preset conditions, that is, the duration for which the actual speed of the motor is greater than zero and less than the first threshold is not reached the first preset duration, or the target speed of the motor is not zero, then the target speed of the motor is reduced according to the preset deceleration, and the feedback speed of the motor is controlled to be the actual speed of the motor.

[0059] In the first n speed control cycles after the vehicle's accelerator is released, the actual motor speed is generally high, exceeding the first threshold. Therefore, in the current speed control cycle, the target motor speed is reduced according to a preset deceleration. That is, the target speed for the current speed control cycle is the target speed of the previous speed control cycle minus the preset deceleration, and the feedback speed of the motor is its actual speed. This facilitates determining the deviation between the actual and target motor speeds. Based on this deviation, the voltage input to the motor is controlled to make the motor speed approach or equal to the target speed, thus ensuring the motor speed follows the target speed and gradually decelerates. Here, n is an integer greater than or equal to 0, without specific limitations.

[0060] Furthermore, when the actual speed of the motor is greater than the first threshold, or the target speed is not zero, the output of the field weakening regulator is not controlled, that is, the field weakening regulator outputs normally, that is, the field weakening regulator outputs the third output value normally according to the rated speed and target speed of the motor.

[0061] S103. Control the feedback speed of the motor to zero and turn off the output of the field weakening regulator.

[0062] The field weakening regulator is the core control module for enabling the motor to operate at speeds exceeding its rated speed. It primarily maintains the motor's output capacity by adjusting the magnetic field strength (usually by reducing the excitation flux) when the motor speed exceeds its rated speed, thereby expanding the speed range. In other words, when the motor requires a higher speed (above its rated speed), the field weakening regulator reduces the excitation current, which in turn reduces the excitation voltage, facilitating the provision of a larger torque voltage to the motor and enabling it to achieve a higher speed.

[0063] Specifically, after the vehicle's accelerator is released, and after n speed control cycles, if the motor's actual speed is less than the first threshold but greater than zero, and the target speed decreases to zero, it indicates that the motor's actual speed is low. Therefore, the feedback speed control for the motor is set to zero, meaning it is no longer adjusted based on the motor's actual speed. The output of the field weakening regulator is also turned off, meaning the field weakening regulator's output value is zero.

[0064] S104. Determine the first output value of the speed control strategy corresponding to the current speed control cycle based on the target speed and the feedback speed of the motor; wherein, the speed control strategy includes a speed proportional term and a speed integral term.

[0065] Specifically, the speed control strategy can be a proportional-integral (PI) control strategy. The proportional term reflects the deviation between the target speed and the feedback speed of the motor in each speed control cycle. The integral term reflects the cumulative deviation between the target speed and the feedback speed of the motor since it started running after power-on. That is, the integral term of the speed control cycle is related to the deviation between the target speed and the feedback speed in the current speed control cycle, and is also related to the integral term of the previous speed control cycle. The first output value of the speed control strategy can be the sum of the values ​​of the proportional term and the integral term. Therefore, the first output value can be output based on the deviation between the target speed and the feedback speed, facilitating motor operation control based on this deviation, so that the motor speed is close to or equal to the target speed.

[0066] When the actual speed of the motor is greater than the first threshold, or the target speed is greater than zero, the feedback speed of the motor is the actual speed of the motor. The motor operation can then be controlled according to the deviation between the target speed and the actual speed, so that the actual speed of the motor follows the target speed and the motor gradually decelerates.

[0067] When the actual speed of the motor is greater than zero and less than the first threshold, and the target speed is zero, the feedback speed of the motor is zero. Then the deviation between the target speed and the feedback speed is zero, making the speed proportional term zero. The speed integral term no longer accumulates, that is, the speed integral term remains unchanged, and the first output value of the speed control strategy remains unchanged.

[0068] S105. Determine the second output value of the first current control strategy corresponding to the current speed control cycle based on the first output value corresponding to the current speed control cycle; wherein, the first current control strategy includes a first current proportional term and a first current integral term.

[0069] Specifically, the first output value corresponding to the current speed control cycle can be used as the first target current of the first current control strategy under the current speed control cycle. The first current control strategy can be a first current proportional-integral control strategy. The first current proportional term reflects the deviation between the first target current and the first actual current of the motor under each speed control cycle, and the first current integral term reflects the cumulative deviation between the first target current and the first actual current of the motor since the motor started running after power-on. That is, the first current integral term under the current speed control cycle is related to the deviation between the first target current and the first actual current under the current speed control cycle, and is also related to the first current integral term of the previous speed control cycle. The second output value of the first current control strategy can be the sum of the values ​​of the first current proportional term and the first current integral term, which facilitates controlling the motor operation according to the deviation between the first target current and the first actual current, so that the motor speed is close to or equal to the target speed.

[0070] Wherein, the first actual current is the actual current of the Q-axis (quadrature axis) of the motor, and the first target current is the target current of the Q-axis of the motor. The first current control strategy can control the voltage of the Q-axis of the motor.

[0071] When the actual speed of the motor is greater than the first threshold, or the target speed is greater than zero, the feedback speed of the motor is the actual speed of the motor. The first output value of the speed control strategy follows the deviation between the target speed and the actual speed, that is, the first target current follows the deviation between the target speed and the actual speed, so that the second output value follows the deviation between the target speed and the actual speed, so that the actual speed of the motor can follow the target speed and the motor gradually decelerates.

[0072] When the actual speed of the motor is greater than zero and less than the first threshold, and the target speed is zero, the feedback speed of the motor is zero. Then the first output value of the speed control strategy remains unchanged, that is, the first target current remains unchanged. The second output value of the first current control strategy follows the first target current, so that the second output value tends to be constant, which makes it easier to control the vehicle to stop stably.

[0073] S106. Determine the fourth output value of the second current control strategy corresponding to the current speed control cycle based on the first output value corresponding to the current speed control cycle and the third output value of the field weakening regulator, and control the motor operation based on the second output value and the fourth output value; wherein, the second current control strategy includes a second current proportional term and a second current integral term.

[0074] Specifically, the second target current of the second current control strategy under the current speed control cycle can be determined based on the first target current (first output value) corresponding to the current speed control cycle and the third output value of the field weakening regulator. The second current control strategy can be a second current proportional-integral control strategy. The second current proportional term reflects the deviation between the second target current and the second actual current of the motor under each speed control cycle, and the second current integral term reflects the cumulative deviation between the second target current and the second actual current of the motor since the motor started running after power-on. That is, the second current integral term under the current speed control cycle is related to the deviation between the second target current and the second actual current under the current speed control cycle, and is also related to the second current integral term of the previous speed control cycle. The fourth output value of the second current control strategy can be the sum of the values ​​of the second current proportional term and the second current integral term. Therefore, the motor operation can be controlled according to the deviation between the second target current and the second actual current of the motor, so that the motor speed is close to or equal to the target speed.

[0075] Wherein, the second actual current is the actual current of the motor's D-axis (direct axis), and the second target current is the target current of the motor's D-axis. The second current control strategy can control the voltage of the motor's D-axis.

[0076] For example, the second and fourth output values ​​can be transformed by coordinates and then pulse width modulation can be performed to obtain a control signal. The control signal is then transmitted to the control electrode of the power transistor in the voltage conversion circuit (e.g., inverter circuit) connected to the motor, controlling the voltage output of the voltage conversion circuit to the motor, thereby adjusting the motor speed so that the motor speed follows the target speed.

[0077] When the actual speed of the motor is greater than the first threshold, or the target speed is greater than zero, the feedback speed of the motor is the actual speed of the motor. The first output value of the speed control strategy follows the deviation between the target speed and the actual speed, that is, the first target current follows the deviation between the target speed and the actual speed, and the field weakening regulator outputs normally, that is, the field weakening regulator outputs the third output value according to the rated speed and the target speed of the motor. Then the second target current follows the deviation between the target speed and the actual speed and the third output value of the field weakening regulator, so that the actual speed of the motor can follow the target speed and the motor gradually decelerates.

[0078] When the actual speed of the motor is greater than zero and less than the first threshold, and the target speed is zero, the feedback speed of the motor is controlled to be zero, and the output of the field weakening regulator is turned off. That is, the third output value of the field weakening regulator is zero. Then the first output value of the speed control strategy remains unchanged, that is, the first target current remains unchanged, and the second target current also remains unchanged. The fourth output value of the second current control strategy follows the change of the second target current, so that the fourth output value tends to be constant. That is, both the third and fourth output values ​​remain constant, thereby controlling the voltage transmitted to the motor to be constant, which makes it easier to control the vehicle to stop stably.

[0079] In this way, it can avoid the situation where the actual speed of the motor is greater than zero and less than the first threshold, and the target speed is zero. In this way, the first output value is adjusted according to the actual speed of the motor, and the second and fourth output values ​​are adjusted according to the first output value. This would cause the second and fourth output values ​​to keep changing, which would make the actual speed of the motor fluctuate around 0, and the vehicle would roll back or slip. This ensures that the vehicle can stop stably and can control the vehicle parking better.

[0080] It should be noted that after the vehicle's accelerator is released, steps S101 to S106 are executed in each speed control cycle. That is, after the vehicle's accelerator is released, steps S101 to S106 are executed in a loop. After each execution of step S106, the process returns to executing step S101.

[0081] The technical solution of this embodiment, after the vehicle's accelerator is released, when the actual speed of the motor is greater than a first threshold or the target speed is greater than zero, reduces the target speed of the motor according to a preset deceleration, and controls the feedback speed of the motor to be the actual speed of the motor. This allows the speed control strategy to periodically determine a first output value based on the deviation between the target speed and the actual speed, i.e., to determine the first target current of the first current control strategy. The second output value of the first current control strategy and the fourth output value of the second current control strategy follow the deviation between the target speed and the actual speed. Therefore, the motor operation is controlled based on the second and fourth output values, allowing the motor speed to follow the target speed change. As the target speed gradually decreases (periodically decreases), the motor speed also gradually decreases (periodically decreases). When the actual speed of the motor is greater than zero and less than the first threshold, and the target speed is zero, it indicates that the actual speed of the motor is small, close to 0. Since there is an error in the acquisition of the actual speed of the motor, and the duration of the actual speed of the motor being close to 0 (greater than zero and less than the first threshold) has exceeded the first preset duration, it indicates that the vehicle has reached equilibrium, that is, the torque provided by the motor and the external forces (friction and gravity, etc.) acting on the vehicle have reached equilibrium, indicating that the vehicle has stopped. The feedback speed of the control motor is set to zero, ensuring zero deviation between the target speed and the feedback speed. This results in a zero proportional term for the speed and no further accumulation of the integral term. The first output value of the speed control strategy remains constant, meaning the first target current remains constant. The second output value of the first current control strategy follows the first target current, making the second output value tend to be constant. Furthermore, the output of the field weakener is turned off, meaning the third output value of the field weakener is zero. The second target current also remains constant, making the fourth output value tend to be constant. Since both the third and fourth output values ​​remain constant, the motor operation is controlled based on these values, ensuring a constant output torque and allowing the vehicle to stop stably. This avoids situations where the actual motor speed is greater than zero but less than the first threshold, and the target speed is zero, and the first output value is still adjusted according to the actual motor speed. This would prevent the second and fourth output values ​​from constantly changing, causing the motor speed to fluctuate around zero, potentially leading to vehicle rollback or slippage. This ensures stable vehicle stopping, improves vehicle parking control, and enhances the driving experience.

[0082] Based on the above technical solutions, the following describes in detail the methods for the speed control strategy to output a first output value, the first current control strategy to output a second output value, and the second current control strategy to output a fourth output value, but this is not intended to limit this application.

[0083] Optionally, the first output value of the speed control strategy corresponding to the current speed control cycle is determined based on the target speed and the feedback speed of the motor, including:

[0084] Step a1: Multiply the difference between the target speed corresponding to the current speed control cycle and the feedback speed of the motor by the speed proportional coefficient, and use the product as the speed proportional term of the speed control strategy.

[0085] For example, if the target speed is Vref, the actual speed of the motor is Vfab, and the speed proportionality coefficient is Kp, then the speed proportionality term... for For example, if the current speed control cycle is the m-th speed control cycle, where m is an integer greater than 1, and the target speed corresponding to the current speed control cycle is... The actual speed corresponding to the current speed control cycle is The speed proportional term corresponding to the current speed control cycle is: ,but .

[0086] Step a2: Multiply the product of the speed proportional term and the speed integral coefficient corresponding to the current speed control cycle, and add the speed integral term corresponding to the previous speed control cycle to obtain the speed integral term corresponding to the current speed control cycle.

[0087] For example, the integral coefficient of the speed is Ki. For instance, if the current speed control cycle is the m-th speed control cycle, where m is an integer greater than 1, the proportional term of the speed control cycle corresponding to the current speed control cycle is... The integral term of the speed corresponding to the previous speed control cycle is The integral term of the current speed control cycle is: ,but .

[0088] Step a3: Take the sum of the proportional term and integral term of the speed corresponding to the current speed control cycle as the first output value corresponding to the current speed control cycle.

[0089] For example, the speed ratio term is The integral term of the rotational speed is If the first output value of the speed control strategy is Vout, then For example, if the current speed control cycle is the m-th speed control cycle, the corresponding speed proportional term for the current speed control cycle is: The integral term of the current speed control cycle is: The first output value of the speed control strategy corresponding to the current speed control cycle is ,but .

[0090] Optionally, the second output value of the first current control strategy corresponding to the current speed control cycle is determined based on the first output value corresponding to the current speed control cycle, including:

[0091] Step b1: Multiply the difference between the first output value and the first actual current of the motor corresponding to the current speed control cycle by the first current proportional coefficient, and use the product as the first current proportional term corresponding to the current speed control cycle.

[0092] Specifically, the first output value corresponding to the current speed control cycle is the first target current of the first current control strategy. For example, the first target current is... The first actual current is The first current proportionality coefficient is Then the first current proportional term for For example, if the current speed control cycle is the m-th speed control cycle, where m is an integer greater than 1, the first target current corresponding to the current speed control cycle is... The first actual current corresponding to the current speed control cycle is The first current proportional term corresponding to the current speed control cycle is: ,but .

[0093] Step b2: Multiply the product of the first current proportional term and the first current integral coefficient corresponding to the current speed control cycle, and add the first current integral term corresponding to the previous speed control cycle to obtain the first current integral term corresponding to the current speed control cycle.

[0094] For example, the first current integral coefficient is The current speed control cycle is the m-th speed control cycle, and the first current proportional term corresponding to the current speed control cycle is: The first current integral term corresponding to the previous speed control cycle is: The first current integral term corresponding to the current speed control cycle is: ,but .

[0095] Step b3: Take the sum of the first current proportional term and the first current integral term corresponding to the current speed control cycle as the second output value corresponding to the current speed control cycle.

[0096] For example, if the current speed control cycle is the m-th speed control cycle, the first current proportional term corresponding to the current speed control cycle is: The first current integral term corresponding to the current speed control cycle is: The second output value corresponding to the current speed control cycle is ,but .

[0097] Optionally, a fourth output value for the second current control strategy corresponding to the current speed control cycle is determined based on the first output value corresponding to the current speed control cycle and the third output value of the field weakening regulator, including:

[0098] Step c1: Determine the second target current of the second current control strategy corresponding to the current speed control cycle by combining the product of the first output value corresponding to the current speed control cycle and the preset coefficient with the sum of the third output value of the field weakening regulator.

[0099] Specifically, the second target current of the second current control strategy corresponding to the current speed control cycle is determined by summing the product of the first output value corresponding to the current speed control cycle and a preset coefficient with the third output value of the field weakening regulator. This second target current is correlated with the first output value output by the speed control strategy based on the deviation between the target speed and the feedback speed, and also correlated with the third output value of the field weakening regulator. Consequently, the fourth output value of the second current control strategy follows the changes in the target speed and the third output value, allowing the actual speed of the motor to follow the target speed, resulting in gradual motor deceleration. Furthermore, when the required motor speed is high, outputting the fourth output value based on the third output value can enhance the motor's output capability.

[0100] Step c2: Multiply the difference between the second target current and the second actual current of the motor corresponding to the current speed control cycle by the second current proportional coefficient, and use the product as the second current proportional term corresponding to the current speed control cycle.

[0101] For example, the second target current is The second actual current is The second current proportionality coefficient is Then the second current proportional term for For example, if the current speed control cycle is the m-th speed control cycle, where m is an integer greater than 1, the second target current corresponding to the current speed control cycle is... The second actual current corresponding to the current speed control cycle is The second current proportional term corresponding to the current speed control cycle is: ,but .

[0102] Step c3: Multiply the product of the second current proportional term and the second current integral coefficient corresponding to the current speed control cycle, and add the second current integral term corresponding to the previous speed control cycle to obtain the second current integral term corresponding to the current speed control cycle.

[0103] For example, the second current integral coefficient is The current speed control cycle is the m-th speed control cycle, and the second current proportional term corresponding to the current speed control cycle is: The second current integral term corresponding to the previous speed control cycle is The second current integral term corresponding to the current speed control cycle is: ,but .

[0104] Step c4: Take the sum of the second current proportional term and the second current integral term corresponding to the current speed control cycle as the fourth output value corresponding to the current speed control cycle.

[0105] For example, if the current speed control cycle is the m-th speed control cycle, the second current proportional term corresponding to the current speed control cycle is: The second current integral term corresponding to the current speed control cycle is: The fourth output value corresponding to the current speed control cycle is ,but .

[0106] Based on the above technical solution, optionally, step c1, determining the second target current of the second current control strategy corresponding to the current speed control cycle by summing the product of the first output value corresponding to the current speed control cycle and the preset coefficient with the third output value of the field weakening regulator, includes:

[0107] Step c11: The product of the first output value corresponding to the current speed control cycle and the preset coefficient, and the sum of the third output value of the field weakening regulator, are used as the initial target current.

[0108] For example, if the preset coefficient is N, the first target current (first output value) is... The third output value of the field weakening regulator is The initial target current is ,but For example, the preset coefficient is 1 or 2, such as the preset coefficient being 1, so that the second target current follows the change of the first output value.

[0109] Step c12: If the initial target current is greater than or equal to the first current threshold, then set the initial target current to the second target current of the second current control strategy corresponding to the current speed control cycle.

[0110] Specifically, if the initial target current is greater than or equal to the first current threshold, then the initial target current is the second target current. A fourth output value can then be output based on the first output value (the deviation between the target speed and the feedback speed) and the third output value of the field weakening regulator. This causes the fourth output value of the second current control strategy to change with the target speed and the third output value, allowing the actual speed of the motor to follow the target speed, thus gradually decelerating the motor.

[0111] Step c13: If the initial target current is less than the first current threshold, then set the first current threshold to the second target current of the second current control strategy corresponding to the current speed control cycle.

[0112] Specifically, if the initial target current is less than the first current threshold, the initial target current is too small, resulting in a small fourth output value of the second current control strategy. This is insufficient to maintain the rotating magnetic field of the induction motor, preventing the rotor of the induction motor from rotating normally. By setting the first current threshold to the second target current of the second current control strategy corresponding to the current speed control cycle when the initial target current is less than the first current threshold, the second target current of the second current control strategy is always greater than or equal to the first current threshold, ensuring the rotating magnetic field of the induction motor and thus guaranteeing the normal operation of the motor.

[0113] Based on the above technical solutions, Figure 2 This is a flowchart of another vehicle parking control method based on an induction motor provided by an embodiment of the present invention. Optionally, refer to... Figure 2 Vehicle parking control methods based on induction motors include:

[0114] S201. After the accelerator of the vehicle is released, determine whether the motor meets the preset conditions. If not, proceed to step S202; if yes, proceed to step S203. Wherein, the motor meets the preset conditions as follows: the actual speed of the motor is greater than zero and the duration of the maintenance of the first threshold is greater than the first preset duration, and the target speed of the motor is zero.

[0115] S202. Reduce the target speed of the motor according to the preset deceleration, and control the feedback speed of the motor to be the actual speed of the motor.

[0116] S203. Control the feedback speed of the motor to zero and turn off the output of the field weakening regulator.

[0117] S204. Determine whether the actual speed of the motor is greater than the second threshold, or whether the duration of the motor's actual speed being non-zero is greater than the second preset duration. If not, proceed to step S206; if yes, proceed to step S205.

[0118] The second threshold is greater than the first threshold. The actual motor speed not being zero includes both cases where it is greater than zero and cases where it is less than zero.

[0119] S205, The feedback speed of the control motor is the actual speed of the motor.

[0120] Specifically, if the duration for which the actual motor speed is greater than zero and less than the first threshold is longer than the first preset duration, and the target motor speed is zero, after the feedback speed of the motor is zero and the output of the field weakening regulator is turned off, the first output value of the speed control strategy remains unchanged, and the second output value of the first current control strategy and the fourth output value of the second current control strategy remain unchanged, resulting in a stable vehicle stop. The voltage output to the motor balances the motor's output torque with external forces (friction and gravity, etc.). However, the control of the motor is not terminated, and the speed control cycle continues to be executed cyclically. Subsequently, if the actual motor speed is greater than the second threshold, or if the duration for which the actual motor speed is not zero is longer than the second preset duration, it indicates that the motor's output torque is no longer balanced with external forces (friction and gravity, etc.), meaning that the vehicle's operating conditions have changed (e.g., changes in vehicle weight), causing the motor to rotate under the influence of external forces. At this point, by controlling the feedback speed of the motor to be the actual speed of the motor, and the target speed of the motor is already zero, the speed control strategy continues to output a first output value based on the deviation between the actual speed of the motor and the target speed. This causes the first current control strategy to output a second output value based on the deviation between the actual speed of the motor and the target speed, and the second current control strategy to output a fourth output value based on the deviation between the actual speed of the motor and the target speed. This adjusts the speed of the motor so that it follows the target speed, thereby preventing the vehicle from going out of control after changes in operating conditions. This achieves stable vehicle parking and can effectively control vehicle parking.

[0121] Optionally, while controlling the feedback speed of the motor to be the actual speed of the motor, the field weakening regulator can be controlled to output normally. That is, the field weakening regulator is controlled to output a third output value according to the rated speed and target speed of the motor, so that the second current control strategy outputs a fourth output value according to the deviation between the actual speed and the target speed of the motor and the third output value, thereby better controlling the operation of the motor.

[0122] S206. Determine the first output value of the speed control strategy corresponding to the current speed control cycle based on the target speed and the feedback speed of the motor; wherein, the speed control strategy includes a speed proportional term and a speed integral term.

[0123] S207. Determine the second output value of the first current control strategy corresponding to the current speed control cycle based on the first output value corresponding to the current speed control cycle; wherein, the first current control strategy includes a first current proportional term and a first current integral term.

[0124] S208. Determine the fourth output value of the second current control strategy corresponding to the current speed control cycle based on the first output value corresponding to the current speed control cycle and the third output value of the field weakening regulator, and control the motor operation based on the second output value and the fourth output value; wherein, the second current control strategy includes a second current proportional term and a second current integral term.

[0125] It should be noted that after the vehicle's accelerator is released, steps S201 to S208 are executed in each speed control cycle. That is, after the vehicle's accelerator is released, steps S201 to S208 are executed in a loop. After each execution of step S208, the process returns to executing step S201.

[0126] Based on the above technical solutions, Figure 3 This is a flowchart of another vehicle parking control method based on an induction motor provided by an embodiment of the present invention. Optionally, refer to... Figure 3 Vehicle parking control methods based on induction motors include:

[0127] S301. After the vehicle's accelerator is released, determine whether the motor meets the preset conditions. If not, proceed to step S302; if yes, proceed to step S303. Wherein, the motor meets the preset conditions if the actual speed of the motor is greater than zero and the duration of the maintenance of the first threshold is greater than the first preset duration, and the target speed of the motor is zero.

[0128] S302. Reduce the target speed of the motor according to the preset deceleration, and control the feedback speed of the motor to be the actual speed of the motor.

[0129] S303, control the feedback speed of the motor to zero and turn off the output of the field weakening regulator.

[0130] S304. Determine the first output value of the speed control strategy corresponding to the current speed control cycle based on the target speed and the feedback speed of the motor; wherein, the speed control strategy includes a speed proportional term and a speed integral term.

[0131] S305. Determine whether the duration for which the first output value is less than the second current threshold is greater than the third preset duration. If not, proceed to step S306; if yes, proceed to step S308.

[0132] Specifically, if the first output value is less than the second current threshold, it indicates that the motor does not need to provide a large torque to stop the vehicle. This means that during the deceleration process of the motor, the speed integral term of the speed control strategy will not accumulate a large value, indicating that the vehicle is on flat ground. If the first output value is greater than the second current threshold, it indicates that the speed integral term of the speed control strategy is large, and the output value of the speed control strategy is large, indicating that the vehicle is on a slope. In this case, the speed control strategy, the first current control strategy, and the second current control strategy will continue to be executed with the motor feedback speed at zero and the output of the field weakener regulator at zero to maintain the vehicle's parking position on the slope.

[0133] S306. Determine the second output value of the first current control strategy corresponding to the current speed control cycle based on the first output value corresponding to the current speed control cycle; wherein, the first current control strategy includes a first current proportional term and a first current integral term.

[0134] S307. Determine the fourth output value of the second current control strategy corresponding to the current speed control cycle based on the first output value corresponding to the current speed control cycle and the third output value of the field weakening regulator, and control the motor operation based on the second output value and the fourth output value; wherein, the second current control strategy includes a second current proportional term and a second current integral term.

[0135] S308, disable the output of the speed control strategy, the first current control strategy, and the second current control strategy.

[0136] Specifically, if the duration for which the first output value is less than the second current threshold is greater than the third preset duration, it indicates that the motor does not need to provide a large torque to stop the vehicle. This means that during the deceleration process of controlling the motor, the speed integral term of the speed control strategy will not accumulate a large value. Therefore, the vehicle is on flat ground, and there is no need for the motor to output torque to counteract a large external force (friction or gravity, etc.). If the duration for which the first output value is less than the second current threshold is greater than the third preset duration, it indicates that the first output value is very small and the duration is long, indicating that the vehicle has come to a stable stop. In this case, the outputs of the speed control strategy, the first current control strategy, and the second current control strategy are turned off, so that the motor no longer outputs torque, thus reducing power consumption. This avoids the problem of the second target current always being greater than or equal to the first current threshold, resulting in a non-zero fourth output value and thus a non-zero motor current, leading to wasted power.

[0137] Thus, if the vehicle is on a slope, the first output value is maintained, and if this value is relatively large, exceeding the second current threshold, the second and fourth output values ​​are also maintained, thereby balancing the motor's output torque with external forces (such as gravity) to keep the vehicle stationary on the slope. If the vehicle is on flat ground, after the duration for which the first output value is less than the second current threshold exceeds a third preset duration, the outputs of the speed control strategy, the first current control strategy, and the second current control strategy are turned off, allowing the vehicle to stop stably and reducing power consumption.

[0138] Specifically, shutting down the outputs of the speed control strategy, the first current control strategy, and the second current control strategy can be achieved by turning off all transistors in the voltage conversion circuit (e.g., inverter circuit) connected to the motor, so that no voltage is output to the motor, and the motor no longer outputs torque.

[0139] It should be noted that after the vehicle's accelerator is released, steps S301 to S307 are executed in each speed control cycle. That is, after the vehicle's accelerator is released, steps S301 to S307 are executed in a loop. After each execution of step S307, the execution of step S301 is returned. After the duration of the first output value being less than the second current threshold is greater than the third preset duration, the output of the speed control strategy, the first current control strategy, and the second current control strategy is turned off.

[0140] Based on the above technical solutions, optionally, after controlling the feedback speed of the motor to zero and turning off the output of the field weakening regulator, the solution further includes:

[0141] If a braking signal is received, the speed integral term of the speed control strategy is gradually reduced to zero according to a preset number of times.

[0142] Specifically, the vehicle may also include a handbrake. After the driver operates the handbrake to apply the brakes, the vehicle parking control device based on the induction motor receives a braking signal, i.e., a handbrake activation signal. The speed integral term of the speed control strategy then gradually decreases to zero according to a preset number of times. Since the target speed of the motor is zero and the feedback speed is zero when the vehicle is parked, the speed proportional term of the speed control strategy is zero, leaving only the speed integral term. Therefore, the speed integral term of the speed control strategy gradually decreases to zero according to a preset number of times, causing the first output value of the speed control strategy to gradually decrease to zero according to a preset number of times.

[0143] In this way, the force used to maintain the vehicle's position on the slope by the motor's output torque can be transferred to the handbrake, allowing the handbrake to hold the vehicle stationary without relying on the motor's output torque. Furthermore, by gradually reducing the speed integral term of the speed control strategy to zero after a preset number of cycles, the first output value of the speed control strategy changes more slowly. Consequently, the second output value of the first current control strategy changes more slowly, and the fourth output value of the second current control strategy changes more slowly. This helps prevent significant vehicle movement, improving the stability and reliability of vehicle control and enhancing the driving experience.

[0144] After the speed integral term gradually decreases to zero according to a preset number of times, the outputs of the speed control strategy, the first current control strategy, and the second current control strategy can be turned off, or the outputs of the speed control strategy, the first current control strategy, and the second current control strategy can remain on. Even if the outputs of the speed control strategy, the first current control strategy, and the second current control strategy are not turned off, since both the target speed and the actual speed are zero, and the speed integral term is also zero, the outputs of the speed control strategy, the first current control strategy, and the second current control strategy are all zero. The transistor in the voltage-speed circuit connected to the motor is turned off, and no voltage is transmitted to the motor.

[0145] This invention also provides a vehicle parking control device based on an induction motor. This induction motor-based vehicle parking control device is used to execute the vehicle parking control method based on an induction motor provided in any embodiment of this invention. The induction motor-based vehicle parking control device can be a vehicle controller, or the vehicle controller can include an induction motor-based vehicle parking control device; no limitation is made here. The vehicle controller is a controller that controls the operation of the motor.

[0146] Figure 4 This is a schematic diagram of a vehicle parking control device based on an induction motor provided in an embodiment of the present invention. (Refer to...) Figure 4 The vehicle parking control device based on an induction motor includes:

[0147] The parameter control module 110 is used to determine whether the motor meets the preset conditions after the accelerator of the vehicle is released; if the motor meets the preset conditions, the feedback speed of the motor is controlled to be zero and the output of the field weakening regulator is turned off; otherwise, the target speed of the motor is reduced according to the preset deceleration and the feedback speed of the motor is controlled to be the actual speed of the motor; wherein, the motor meets the preset conditions when the duration of the actual speed of the motor being greater than zero and less than the first threshold is greater than the first preset duration, and the target speed of the motor is zero.

[0148] The speed control module 120 is used to determine the first output value of the speed control strategy corresponding to the current speed control cycle based on the target speed and the feedback speed of the motor; wherein, the speed control strategy includes a speed proportional term and a speed integral term;

[0149] The first current control module 130 is used to determine the second output value of the first current control strategy corresponding to the current speed control cycle based on the first output value corresponding to the current speed control cycle; wherein, the first current control strategy includes a first current proportional term and a first current integral term;

[0150] The second current control module 140 is used to determine the fourth output value of the second current control strategy corresponding to the current speed control cycle based on the first output value corresponding to the current speed control cycle and the third output value of the field weakening regulator, and to control the motor operation based on the second output value and the fourth output value; wherein, the second current control strategy includes a second current proportional term and a second current integral term.

[0151] The vehicle parking control device based on an induction motor provided in this embodiment of the invention can execute the vehicle parking control method based on an induction motor provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0152] This invention also provides a vehicle that includes a vehicle parking control device based on an induction motor provided in any embodiment of the invention. Therefore, the vehicle provided in this embodiment has the same beneficial effects as the vehicle parking control device based on an induction motor provided in any embodiment of the invention, and will not be described again here.

[0153] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0154] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A vehicle parking control method based on an induction motor, characterized in that, include: After the vehicle's accelerator is released, it is determined whether the motor meets the preset conditions; wherein, the motor meets the preset conditions if the actual speed of the motor is greater than zero and the duration of the maintenance of the first threshold is greater than the first preset duration, and the target speed of the motor is zero. If the motor meets the preset conditions, the feedback speed of the motor is controlled to be zero and the output of the field weakening regulator is turned off; otherwise, the target speed of the motor is reduced according to the preset deceleration and the feedback speed of the motor is controlled to be the actual speed of the motor. The first output value of the speed control strategy corresponding to the current speed control cycle is determined based on the target speed and the feedback speed of the motor; wherein, the speed control strategy includes a speed proportional term and a speed integral term; The second output value of the first current control strategy corresponding to the current speed control cycle is determined based on the first output value corresponding to the current speed control cycle; wherein, the first current control strategy includes a first current proportional term and a first current integral term; The fourth output value of the second current control strategy corresponding to the current speed control cycle is determined based on the first output value corresponding to the current speed control cycle and the third output value of the field weakening regulator. The motor is then controlled to run based on the second output value and the fourth output value. The process then returns to the step of determining whether the motor meets the preset conditions. The second current control strategy includes a second current proportional term and a second current integral term.

2. The method according to claim 1, characterized in that, The step of determining the first output value of the speed control strategy corresponding to the current speed control cycle based on the target speed and the feedback speed of the motor in the current speed control cycle includes: The product of the difference between the target speed corresponding to the current speed control cycle and the feedback speed of the motor, and the speed proportional coefficient, is used as the speed proportional term of the speed control strategy. The product of the proportional speed term and the integral speed coefficient corresponding to the current speed control cycle is added to the integral speed term corresponding to the previous speed control cycle to obtain the integral speed term corresponding to the current speed control cycle. The sum of the proportional and integral terms of the speed corresponding to the current speed control cycle is used as the first output value corresponding to the current speed control cycle.

3. The method according to claim 1, characterized in that, The step of determining the second output value of the first current control strategy corresponding to the current speed control cycle based on the first output value corresponding to the current speed control cycle includes: The product of the difference between the first output value and the first actual current of the motor corresponding to the current speed control cycle and the first current proportional coefficient is used as the first current proportional term corresponding to the current speed control cycle. The product of the first current proportional term and the first current integral coefficient corresponding to the current speed control cycle is added to the first current integral term corresponding to the previous speed control cycle to obtain the first current integral term corresponding to the current speed control cycle. The sum of the first proportional term and the first integral term of the current speed control cycle is used as the second output value corresponding to the current speed control cycle.

4. The method according to claim 1, characterized in that, The step of determining the fourth output value of the second current control strategy corresponding to the current speed control cycle based on the first output value corresponding to the current speed control cycle and the third output value of the field weakening regulator includes: The second target current of the second current control strategy corresponding to the current speed control cycle is determined by the sum of the product of the first output value and the preset coefficient corresponding to the current speed control cycle and the third output value of the field weakening regulator. The product of the difference between the second target current and the second actual current of the motor corresponding to the current speed control cycle and the second current proportional coefficient is used as the second current proportional term corresponding to the current speed control cycle. The product of the second current proportional term and the second current integral coefficient corresponding to the current speed control cycle is added to the second current integral term corresponding to the previous speed control cycle to obtain the second current integral term corresponding to the current speed control cycle. The sum of the second current proportional term and the second current integral term corresponding to the current speed control cycle is taken as the fourth output value corresponding to the current speed control cycle.

5. The method according to any one of claims 1-4, characterized in that, After controlling the feedback speed of the motor to zero and turning off the output of the field weakening regulator, before determining the first output value of the speed control strategy corresponding to the current speed control cycle based on the target speed and the feedback speed of the motor, the method further includes: If the actual speed of the motor is greater than the second threshold, or if the duration for which the actual speed of the motor is not zero is greater than the second preset duration, then the feedback speed of the motor is controlled to be the actual speed of the motor.

6. The method according to claim 4, characterized in that, The step of determining the second target current of the second current control strategy corresponding to the current speed control cycle by summing the product of the first output value and the preset coefficient corresponding to the current speed control cycle with the third output value of the field weakening regulator includes: The product of the first output value corresponding to the current speed control cycle and the preset coefficient, and the sum of the third output value of the field weakening regulator, are used as the initial target current. If the initial target current is greater than or equal to the first current threshold, then the initial target current is set to the second target current of the second current control strategy corresponding to the current speed control cycle; If the initial target current is less than the first current threshold, then the first current threshold is set to the second target current of the second current control strategy corresponding to the current speed control cycle.

7. The method according to any one of claims 1-4, characterized in that, After determining the first output value of the speed control strategy corresponding to the current speed control cycle based on the target speed and the feedback speed of the motor, the following steps are also included: If the duration of the first output value being less than the second current threshold is greater than the third preset duration, then the outputs of the speed control strategy, the first current control strategy, and the second current control strategy are turned off.

8. The method according to any one of claims 1-4, characterized in that, After controlling the feedback speed of the motor to zero and turning off the output of the field weakening regulator, the method further includes: If a braking signal is received, the speed integral term of the speed control strategy is gradually reduced to zero according to a preset number of times.

9. A vehicle parking control device based on an induction motor, characterized in that, include: The parameter control module is used to determine whether the motor meets the preset conditions after the vehicle's accelerator is released. If the motor meets the preset conditions, the feedback speed of the motor is controlled to be zero and the output of the field weakening regulator is turned off; otherwise, the target speed of the motor is reduced according to the preset deceleration and the feedback speed of the motor is controlled to be the actual speed of the motor. Wherein, the motor meets the preset conditions if the duration of the maintenance of the actual speed of the motor being greater than zero and less than the first threshold is greater than the first preset duration, and the target speed of the motor is zero. The speed control module is used to determine the first output value of the speed control strategy corresponding to the current speed control cycle based on the target speed and the feedback speed of the motor; wherein, the speed control strategy includes a speed proportional term and a speed integral term; The first current control module is used to determine the second output value of the first current control strategy corresponding to the current speed control cycle based on the first output value corresponding to the current speed control cycle; wherein, the first current control strategy includes a first current proportional term and a first current integral term; The second current control module is used to determine the fourth output value of the second current control strategy corresponding to the current speed control cycle based on the first output value corresponding to the current speed control cycle and the third output value of the field weakening regulator, and to control the motor operation based on the second output value and the fourth output value; wherein, the second current control strategy includes a second current proportional term and a second current integral term.

10. A vehicle, characterized in that, Includes the vehicle parking control device based on an induction motor as described in claim 9.

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