Electric vehicle motor control method and device, motor controller and vehicle

Abstract

The invention provides an electric vehicle motor control method and device, a motor controller and a vehicle, and the method comprises the steps: determining whether a current state is an active tooth leaning state or not according to a vehicle gear, a currently collected motor rotating speed, a preset rotating speed range corresponding to the vehicle gear, a request torque and a preset torque range corresponding to the vehicle gear; the request torque is the torque in a torque control instruction sent by the vehicle control unit; if the current state is the active tooth leaning state, a motor is controlled to output preset torque; and if the current state is not the active tooth leaning state, the motor is controlled to output the request torque. It can be understood that the active tooth leaning state corresponds to the state that the vehicle possibly has the tooth knocking working condition, and when the vehicle state is the active tooth leaning state, the motor is controlled to output the preset torque to ensure that the vehicle outputs the relatively fixed torque, so that tooth surface impact noise is avoided, the NVH performance of the electric vehicle under the low-speed working condition is improved, and the user experience feeling is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobile control, in particular to an electric vehicle motor control method and device, a motor controller and a vehicle. BACKGROUND

[0002] At present, in order to protect the environment, more and more people choose pure electric vehicles as a means of transportation, but pure electric vehicles do not have the engine idle speed characteristics of fuel vehicles, and the driver needs to frequently switch the accelerator pedal and the brake pedal when following at low speed, which affects the driving experience.

[0003] In related technologies, in order to reduce the driving fatigue in low speed mode, when the vehicle is powered on and at a certain speed in D or R, the vehicle controller actively requests torque to drive the vehicle forward or backward, thereby simulating the idle driving of a fuel vehicle, which is called the inching mode.

[0004] However, in the inching mode, the vehicle works in zero torque condition in many cases, at this time, due to torque following error and resistance change, the driving motor driving gear and the reducer driven gear will repeatedly disengage and engage, thereby generating tooth surface impact noise, affecting the vehicle noise, vibration and harshness (NVH), and affecting the driving experience of the driver.

[0005] It should be pointed out that the information disclosed in the background section of the present application is only intended to deepen the understanding of the general background of the present application, and should not be regarded as acknowledging or implying in any form that the information constitutes prior art known to those skilled in the art. SUMMARY

[0006] Therefore, the present application provides an electric vehicle motor control method, device, motor controller and vehicle to solve the problem that in the related art, in the inching mode, the vehicle works in zero torque condition in many cases, at this time, due to torque following error and resistance change, the driving motor driving gear and the reducer driven gear will repeatedly disengage and engage, thereby generating tooth surface impact noise, affecting the vehicle NVH, and affecting the driving experience of the driver.

[0007] In a first aspect, an electric vehicle motor control method is provided, comprising: According to the vehicle gear, the currently collected motor speed, the preset speed range corresponding to the vehicle gear, and the requested torque and the preset torque range corresponding to the vehicle gear, it is determined whether the current state is the active tooth state, and the requested torque is the torque in the torque control instruction sent by the vehicle controller. If the current state is the active tooth engaging state, the motor is controlled to output the preset torque; if the current state is not the active tooth engaging state, the motor is controlled to output the requested torque.

[0008] In the embodiment of the present application, whether the current state is the active tooth engaging state is determined according to the vehicle gear, the collected motor speed and the preset speed range, the requested torque and the preset torque range. If the current state is the active tooth engaging state, the motor is controlled to output the preset torque. It can be understood that the active tooth engaging state corresponds to a state in which the vehicle may exist in the tooth knocking working condition. When the vehicle state is the active tooth engaging state, the motor is controlled to output the preset torque, which can ensure that the vehicle outputs a relatively fixed torque, thereby avoiding the generation of tooth surface impact noise, improving the NVH performance of the electric vehicle in the low-speed working condition, and improving the user experience.

[0009] In a possible implementation, the determination of whether the current state is the active tooth engaging state according to the vehicle gear, the currently collected motor speed and the preset speed range corresponding to the vehicle gear, and the requested torque and the preset torque range corresponding to the vehicle gear comprises: When the vehicle gear is the forward gear, the collected motor speed is located in the first preset speed range and the requested torque is located in the first preset torque range, it is determined that the current state is the active tooth engaging state. Or, when the vehicle gear is the reverse gear, the collected motor speed is located in the second preset speed range and the requested torque is located in the second preset torque range, it is determined that the current state is the active tooth engaging state. The first preset speed range and the second preset speed range are reverse intervals, and the first preset torque range and the second preset torque range are reverse intervals.

[0010] In the embodiment of the present application, different speed ranges and torque ranges are set for the forward gear and the reverse gear of the vehicle, so as to accurately determine whether the current state is the active tooth engaging state.

[0011] In a possible implementation, the method further comprises: When the vehicle gear is the forward gear, the collected motor speed is located in the third preset speed range or the fourth preset speed range, or the requested torque is located in the third preset torque range or the fourth preset torque range, the active tooth engaging state is exited. Or, when the vehicle gear is the reverse gear, the collected motor speed is located in the fifth preset speed range or the sixth preset speed range, or the requested torque is located in the fifth preset torque range or the sixth preset torque range, the active tooth engaging state is exited. The maximum value of the third preset rotating speed range is less than the minimum value of the first preset rotating speed range, the minimum value of the fourth preset rotating speed range is greater than the maximum value of the first preset rotating speed range, the fifth preset rotating speed range and the third preset rotating speed range are reverse intervals, and the sixth preset rotating speed range and the fourth preset rotating speed range are reverse intervals. The maximum value of the third preset torque range is less than the minimum value of the first preset torque range, the minimum value of the fourth preset torque range is greater than the maximum value of the first preset torque range, the fifth preset torque range and the third preset torque range are reverse intervals, and the sixth preset torque range and the fourth preset torque range are reverse intervals.

[0012] In the embodiments of the present application, the rotating speed range and the torque range corresponding to the exiting active tooth engagement state are different from the rotating speed range and the torque range corresponding to the entering active tooth engagement state, and there is a difference, so that the tooth knocking working condition caused by frequently entering or exiting the active tooth engagement state is avoided, thereby improving the NVH performance of the electric vehicle in the low-speed working condition and improving the user experience.

[0013] In a possible implementation, the method further includes: If the vehicle is powered on, the vehicle gear is in the forward gear or the reverse gear, and the current motor control mode is torque control, then whether the current state is the active tooth engagement state is determined according to the vehicle gear, the currently collected motor rotating speed, the preset rotating speed range corresponding to the vehicle gear, the requested torque, and the preset torque range corresponding to the vehicle gear. If any one of the following conditions is not met: the vehicle is powered on, the vehicle gear is in the forward gear or the reverse gear, and the current motor control mode is torque control, then the motor outputs the requested torque.

[0014] In the embodiments of the present application, whether the current state is the active tooth engagement state is determined only when the vehicle is powered on, the vehicle gear is in the forward gear or the reverse gear, and the current motor control mode is torque control, so that the automatic acceleration caused by the active tooth engagement in the unintended vehicle state is avoided, and the user experience is improved.

[0015] In a possible implementation, the method further includes: The rotating speed fluctuation amount and the rotating speed fluctuation node are determined according to the rotating speed before filtering and the rotating speed after filtering. The torque compensation amount is calculated according to the rotating speed fluctuation amount, and the adjustment direction of the torque compensation amount is opposite to the change direction of the rotating speed fluctuation amount. The torque compensation amount is output at the rotating speed fluctuation node.

[0016] In the embodiment of the present application, because the motor speed fluctuates, the torque compensation is superimposed, when the speed suddenly increases, the torque is reduced, when the speed suddenly decreases, the torque is increased, so as to offset the influence of the speed mutation, and avoid the knocking condition.

[0017] In a possible implementation, the method further includes: storing the initial motor speed when the motor torque changes from negative to positive; converting the motor control mode to speed control; outputting a motor speed control signal according to the target speed, the target speed being the sum of the initial motor speed and a preset relative speed, the motor speed control signal being used to control the driving gear of the motor to output the target speed.

[0018] In the embodiment of the present application, when the motor torque changes from negative to positive (i.e. the motor torque crosses zero), the speed control mode is used to control the speed output by the driving gear of the motor, so as to avoid the knocking between the driving gear and the driven gear.

[0019] In a possible implementation, the method further includes: converting the motor control mode to torque control when the motor speed control signal output reaches a preset time length; outputting a motor torque control signal according to the current motor torque and the request torque, so that the motor torque quickly approaches the request torque.

[0020] In the embodiment of the present application, when the torque crosses zero, the speed control time length is controlled within the preset time length, so as to ensure the normal operation of the motor, and the motor torque control signal is outputted, so that the motor torque quickly approaches the request torque, and the response efficiency of the motor is improved.

[0021] In a second aspect, the embodiment of the present application provides a motor control device for an electric vehicle, including: a state determination module, configured to determine whether the current state is the active tooth engaging state according to the vehicle gear, the current collected motor speed, the preset speed range corresponding to the vehicle gear, the request torque and the preset torque range corresponding to the vehicle gear, the request torque being the torque in the torque control instruction sent by the vehicle controller; a control module, configured to control the motor to output the preset torque if the current state is the active tooth engaging state, and control the motor to output the request torque if the current state is not the active tooth engaging state.

[0022] In a third aspect, the embodiment of the present application provides a motor controller, including: a processor; a memory; and a computer program, wherein the computer program is stored in the memory, and the computer program includes instructions, which, when executed by the processor, cause the motor controller to perform the method of any one of the first aspect.

[0023] In a fourth aspect, an embodiment of the present application provides a vehicle, comprising the motor controller of the third aspect.

[0024] It can be understood that the motor control device of the electric vehicle provided in the second aspect, the motor controller provided in the third aspect, and the vehicle provided in the fourth aspect are all used to perform the method provided in the present application. Therefore, the beneficial effects that can be achieved are referable to the beneficial effects in the corresponding method, which will not be described here again. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0026] Figure 1 A schematic diagram of a gear structure provided in an embodiment of the present application; Figure 2 A flowchart of a motor control method of an electric vehicle provided in an embodiment of the present application; Figure 3 A schematic diagram of a torque zero-crossing control curve provided in an embodiment of the present application; Figure 4 A flowchart of another motor control method of an electric vehicle provided in an embodiment of the present application; Figure 5 A schematic diagram of a motor control device of an electric vehicle provided in an embodiment of the present application; Figure 6 A schematic diagram of a motor control device of an electric vehicle provided in an embodiment of the present application; DETAILED DESCRIPTION

[0027] In order to better understand the technical solutions of the present application, the embodiments of the present application will be described in detail below with reference to the drawings.

[0028] It should be clear that the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0029] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "an", "the" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0030] It should be understood that the term "and / or" as used herein simply describes a relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A alone, A and B together, or B alone. Furthermore, the character " / " in this document generally indicates an "or" relationship between the associated objects.

[0031] Currently, in order to protect the environment, more and more people choose pure electric vehicles as their means of transportation. However, pure electric vehicles do not have the engine idling characteristics of fuel vehicles. When following a vehicle at low speed, the driver needs to frequently switch the accelerator and brake pedals, which affects the driving experience.

[0032] In related technologies, in order to reduce driving fatigue in low-speed mode, when the vehicle is powered on and in D or R gear at a certain speed, the vehicle controller will actively request torque to drive the vehicle forward or backward, thereby simulating the idling of a fuel vehicle, which is called creep mode.

[0033] However, in creep mode, the entire vehicle often operates in zero-torque conditions. At this time, due to torque following error and resistance changes, the driving gear of the drive motor and the driven gear of the reducer will repeatedly disengage and engage, thereby generating tooth surface impact noise, affecting the NVH of the entire vehicle and the driver's driving experience.

[0034] For ease of understanding, the specific working principle of gears is exemplified below.

[0035] join Figure 1 , is a schematic diagram of a gear structure provided in an embodiment of the present application. Figure 1 As shown, the gears of the drive motor include a driving gear 101 and a driven gear 102, wherein the gears of the driving gear 101 and the driven gear 102 are meshed with each other, and the driving gear 101 is connected to the driving device. The driving gear 101 is controlled to rotate by the driving device, and the driven gear 102 rotates along with the rotation of the driving gear 101. For example, when the driving gear 101 rotates clockwise, the driven gear 102 rotates counterclockwise; when the driving gear 101 rotates counterclockwise, the driven gear 102 rotates clockwise.

[0036] like Figure 1As shown, the gap between the first tooth 1011 and the second tooth 1012 on the driving gear 101 is larger than the size of the third tooth 1021 on the driven gear 102, so when the driving gear 101 rotates in the clockwise direction, the third tooth 1021 on the driven gear 102 is in close contact with the first tooth 1011, and there is a gap between the third tooth 1021 and the second tooth 1012. At this time, if the rotation direction of the driving gear 101 changes to counterclockwise rotation, it will cause the third tooth 1021 to disengage from the first tooth 1011 and collide with the second tooth 1012, which is the knocking condition, causing tooth surface impact noise and affecting the overall vehicle NVH.

[0037] It should be noted that, Figure 1 The gear structure shown in the figure is only an exemplary illustration and should not be regarded as a limitation of the protection scope of the present application.

[0038] To solve the above problems, the present application provides an electric vehicle motor control method. According to the vehicle gear position, the collected motor speed and the preset speed range, the requested torque and the preset torque range, it is determined whether the current state is the active tooth engaging state. If the current state is the active tooth engaging state, the motor is controlled to output the preset torque. It can be understood that the active tooth engaging state corresponds to the state in which the vehicle may have a knocking condition. When the vehicle state is the active tooth engaging state, controlling the motor to output the preset torque can ensure that the vehicle outputs a relatively fixed torque, thereby avoiding tooth surface impact noise, improving the NVH performance of the electric vehicle in low-speed conditions, and improving the user experience. The specific embodiments will be described in detail below in conjunction with the drawings.

[0039] Referring to Figure 2 A flowchart of an electric vehicle motor control method according to an embodiment of the present application is shown. As shown in the figure, it mainly includes the following steps. Figure 2 As shown in the figure, it mainly includes the following steps.

[0040] Step S201: According to the vehicle gear position, the current collected motor speed and the preset speed range corresponding to the vehicle gear position, and the requested torque and the preset torque range corresponding to the vehicle gear position, it is determined whether the current state is the active tooth engaging state.

[0041] Specifically, the preset speed range and the preset torque range are set in advance according to the vehicle gear position, so as to determine whether the current state is the active tooth engaging state according to the collected motor speed and the requested torque. The requested torque is the torque in the torque control instruction sent by the vehicle controller (VCU).

[0042] In a possible implementation, when the vehicle gear is in the forward gear, the collected motor speed is in a first preset speed range and the requested torque is in a first preset torque range, it is determined that the current state is the active tooth engagement state; or when the vehicle gear is in the reverse gear, the collected motor speed is in a second preset speed range and the requested torque is in a second preset torque range, it is determined that the current state is the active tooth engagement state; wherein the first preset speed range and the second preset speed range are reverse intervals, and the first preset torque range and the second preset torque range are reverse intervals.

[0043] In the embodiment of the application, the first preset speed range is (N1, N2), and the first preset torque range is (T1, T2), that is, when the vehicle gear is in the forward gear, N1 < the collected motor speed < N2 and T1 < the requested torque < T2, it is determined that the current state is the active tooth engagement state. Correspondingly, the second preset speed range is (-N2, -N1), and the second preset torque range is (-T2, -T1), that is, when the vehicle gear is in the reverse gear, -N2 < the collected motor speed < -N1 and -T2 < the requested torque < -T1, it is determined that the current state is the active tooth engagement state.

[0044] N1, N2, T1 and T2 are confirmed by software calibration, N1 is usually the maximum motor speed fluctuation allowed in the case of static vehicle without driving, because vehicle shaking may also cause motor speed fluctuation, so a lower limit is set to avoid false entry into the active tooth engagement state, N2 is usually the upper limit of the speed corresponding to the crawling mode, and the vehicle speed of the crawling mode is usually 3km / h~7km / h or 3km / h~8km / h, so N2 is the speed corresponding to the vehicle speed of 7km / h or 8km / h, and T1 and T2 are usually the requested torque range in the range of 0N·m that may appear in the tooth knocking condition. For example, N1 is 10r / min, N2 is 700r / min, T1 is -0.1N·m, and T2 is 1 N·m.

[0045] It can be understood that different speed ranges and torque ranges are set for different vehicle gears, so as to accurately determine whether the current state is the active tooth engagement state, avoid false entry into the active tooth engagement state, and ensure the driving experience.

[0046] The above steps set the conditions for the vehicle to enter the active tooth engagement state, but the vehicle cannot always be in the active tooth engagement state, so the conditions for exiting the active tooth engagement state need to be set, and when the conditions for exiting the active tooth engagement state are met, the active tooth engagement state is exited, so as to ensure normal driving of the vehicle.

[0047] In a possible implementation, the vehicle can directly exit the active gear engagement state when any one of the conditions for entering the active gear engagement state is not met. However, assuming that the gear position of the vehicle is in the forward gear and the collected motor speed is in the first preset speed range, the vehicle enters the active gear engagement state when the requested torque is in the first preset torque range. However, the vehicle exits the active gear engagement state when the requested torque changes and the requested torque is not in the first preset torque range. This can cause the vehicle to frequently enter or exit the active gear engagement state, and thus the gear knocking condition can frequently occur, which affects the driving experience.

[0048] Therefore, in the embodiments of the present application, the active gear engagement state exit conditions are set as follows: when the gear position of the vehicle is in the forward gear, the collected motor speed is in the third preset speed range or the fourth preset speed range, or the requested torque is in the third preset torque range or the fourth preset torque range, the vehicle exits the active gear engagement state; or when the gear position of the vehicle is in the reverse gear, the collected motor speed is in the fifth preset speed range or the sixth preset speed range, or the requested torque is in the fifth preset torque range or the sixth preset torque range, the vehicle exits the active gear engagement state.

[0049] The maximum value of the third preset speed range is less than the minimum value of the first preset speed range, the minimum value of the fourth preset speed range is greater than the maximum value of the first preset speed range, the fifth preset speed range and the third preset speed range are reverse intervals, and the sixth preset speed range and the fourth preset speed range are reverse intervals. The maximum value of the third preset torque range is less than the minimum value of the first preset torque range, the minimum value of the fourth preset torque range is greater than the maximum value of the first preset torque range, the fifth preset torque range and the third preset torque range are reverse intervals, and the sixth preset torque range and the fourth preset torque range are reverse intervals.

[0050] In a possible implementation, the third preset speed range is (-∞, N3), the fourth preset speed range is (N4, +∞), N3

[0051] Wherein, N3, N4, T3 and T4 are confirmed by software calibration, and the setting principle is not to frequently enter and exit the active tooth engagement function, so as to avoid the knocking tooth working condition. For example, N3 is -10 r / min, N4 is 750 r / min, T3 is -1 N·m, and T4 is 1.5 N·m.

[0052] It can be understood that the rotation speed range and the torque range corresponding to the exit of the active tooth engagement state are different from the rotation speed range and the torque range corresponding to the entry of the active tooth engagement state, and there is a difference, so as to avoid the knocking tooth working condition caused by frequent entry and exit of the active tooth engagement state, thereby improving the NVH performance of the electric vehicle in the low-speed working condition and improving the user experience.

[0053] Because the vehicle gear position includes the forward gear, the reverse gear, the neutral gear and the parking gear, when the vehicle gear position is the neutral gear or the parking gear, the motor speed and the requested torque should be 0, at this time, the motor torque does not need to be adjusted, therefore, only when the vehicle gear position is the forward gear or the reverse gear, it is necessary to determine whether the current state is the active tooth engagement state. In addition, when the vehicle is not powered on, the motor torque also does not need to be adjusted. In addition, only when the motor control mode is the torque control, the motor torque can be adjusted.

[0054] Therefore, in a possible implementation, if the vehicle is powered on, the vehicle gear position is the forward gear or the reverse gear, and the current motor control mode is the torque control, then according to the vehicle gear position, the currently collected motor speed, the preset rotation speed range corresponding to the vehicle gear position, the requested torque and the preset torque range corresponding to the vehicle gear position, it is determined whether the current state is the active tooth engagement state; if any of the vehicle being powered on, the vehicle gear position being the forward gear or the reverse gear, and the current motor control mode being the torque control is not satisfied, the motor is controlled to output the requested torque.

[0055] It can be understood that by limiting the vehicle to be powered on, the vehicle can be prevented from actively engaging the teeth in an unintended vehicle state to cause automatic acceleration, by limiting the vehicle gear position, the motor can be prevented from being blocked in the parking gear and automatically accelerated in the neutral gear, and by limiting the motor control mode, the motor can be prevented from being misresponsive in the rotation speed control mode, thereby ensuring the user experience.

[0056] In a possible implementation, the key gear position is determined to be ON by the key state signal sent by the VCU. It can be understood that if the key gear position is ON, it means that the vehicle is powered on; if it is determined that the key gear position is not ON, it means that the vehicle is not powered on. In addition, the vehicle gear position is determined by the vehicle gear position signal sent by the VCU, the current vehicle gear position is determined, and the torque control mode request signal sent by the VCU is used to determine whether the current vehicle demand is torque control.

[0057] In addition, when any of the above conditions is not met, the motor output request torque is controlled, so as to ensure normal driving of the vehicle and driving experience.

[0058] In step S202, if the current state is the active tooth engagement state, the motor is controlled to output a preset torque; if the current state is not the active tooth engagement state, the motor is controlled to output a request torque.

[0059] Specifically, because the motor control mode in the active tooth engagement state is torque control, the motor can be controlled to output a preset torque, which is obtained by pre-calibration. For example, the preset torque can be 1 N·m. Of course, the preset torque can be set to any value according to actual needs, and the present application does not make a specific limitation in this regard.

[0060] It can be understood that when the current state is not the active tooth engagement state, the motor is controlled to output a request torque, so that the actual output torque of the motor is the same as the expected torque of the driver, and the driving experience is ensured. In addition, if the current state is the active tooth engagement state, the active tooth engagement state enable flag is set to 1, so as to determine the current state by other controllers or devices.

[0061] In actual application, because the whole vehicle resistance changes constantly, the fixed torque tooth engagement compensation strategy cannot adapt to the fluctuation of the motor speed. Therefore, the present application superimposes active anti-shake torque compensation on the basis of the above tooth engagement compensation.

[0062] Specifically, the speed fluctuation amount and the speed fluctuation node are determined according to the speed before filtering and the speed after filtering; the torque compensation amount is calculated according to the speed fluctuation amount, and the adjustment direction of the torque compensation amount is opposite to the change direction of the speed fluctuation amount; and the torque compensation amount is output at the speed fluctuation node.

[0063] In a possible implementation, the difference between the speed before filtering and the speed after filtering is calculated, and the difference is the speed fluctuation amount. The speed fluctuation amount is taken as an input for calculating the compensation torque, and the torque compensation amount is obtained. The adjustment direction of the torque compensation amount is opposite to the change direction of the speed fluctuation amount, that is, when the speed suddenly increases, the torque is reduced, and when the speed suddenly decreases, the torque is increased, so as to offset the influence of the sudden change of the speed and avoid the tooth knock working condition.

[0064] In the present application, the speed before filtering is the speed directly transmitted by the resolver decoding chip, and the resolver decoding chip is a chip in the motor controller for analyzing the position of the rotor in the motor.

[0065] In addition, in the present application, the absolute value of the torque compensation value AT is limited to be less than |T3|, so as to avoid the gear knocking or aggravate the shaking caused by the torque compensation.

[0066] In practical applications, taking the creep mode of the forward gear of the vehicle as an example, as long as the driver does not step on the accelerator pedal, when the motor speed is above N2, the VCU requests negative torque to slow down the vehicle, so that the motor speed is reduced to below N2. When the vehicle is braked to below N2 from a speed greater than N2 and meets other conditions for active tooth engagement, the vehicle exits the energy recovery state and is ready to enter the active tooth engagement state. At this time, the motor torque will transition from negative torque to positive torque, because the VCU will request positive torque in the creep mode to control the speed at N2. When the motor torque transitions from negative torque to positive torque, that is, the torque zero-crossing condition, tooth knocking may occur, resulting in noise.

[0067] To solve this problem, in the embodiments of the present application, when the motor torque changes from negative to positive, the initial motor speed is stored; the motor control mode is converted to speed control; and a motor speed control signal is output according to a target speed, wherein the target speed is the sum of the initial motor speed and a preset relative speed, and the motor speed control signal is used to control the active gear of the motor to output the target speed.

[0068] When the torque reverses and causes the active gear to disengage from the driven gear, because the driven gear has large inertia and slows down slowly, the speed of the driven gear can be considered constant within the time of passing through the gear gap. At this time, the initial motor speed is stored, because when the vehicle is in the forward gear and the torque changes from negative to positive, the motor speed should change from low to high. When the torque is negative, the speed is positive, the speed and the torque direction are opposite, and the motor is in a power generation state. After the torque crosses zero, the torque becomes positive, and the speed is still positive, and the motor is in a driving state. Storing the initial motor speed when the torque crosses zero makes it easier to determine the target speed, and controlling the active gear according to the target speed can reduce the impact of gear engagement.

[0069] In the embodiments of the present application, the target speed is the sum of the initial motor speed and a preset relative speed, and the preset relative speed is a small preset speed value.

[0070] In addition, in practical applications, the motor cannot be controlled by speed all the time, so in the embodiments of the present application, when the motor speed control signal is output for a preset time length, the motor control is converted to torque control; according to the current motor torque and the requested torque, a motor torque control signal is output, so that the motor torque quickly approaches the requested torque.

[0071] In the embodiments of the present application, the preset time length is a time length determined by software calibration. In order to facilitate understanding, the embodiments of the present application provide a torque zero-crossing control curve diagram.

[0072] Referring to Figure 3 A torque zero-crossing control curve diagram is provided for the embodiments of the present application. As shown in Figure 3As shown, when the motor torque reaches the advance strategy torque threshold, the motor control mode is switched to speed control, and a group of pulse width adaptive bidirectional narrow pulse torque sequences are output according to the relative speed target value and the preset relative speed, that is, the pulse width modulation part in Figure 3 When the speed control reaches the preset time length, the motor control mode is switched to torque control. When the motor control mode is just switched to torque control, the motor output torque is made to approach the request torque as soon as possible through curve optimization, so that the output torque meets the driver's expectation. When the torque decreases to meet the active gear engagement condition, the motor outputs a preset torque (i.e., the gear engagement holding torque in Figure 3 ).

[0073] It can be understood that when the motor torque is zero, the speed of the motor driving gear is controlled through speed control, so as to avoid the knocking of the driving gear and the driven gear. Moreover, the speed control time length is controlled within the preset time length, so as to ensure the normal operation of the motor, and the motor torque control signal is output to make the motor torque quickly approach the request torque, thereby improving the response efficiency of the motor.

[0074] Corresponding to the above embodiment, the application further provides another motor control method for an electric vehicle.

[0075] Referring to Figure 4 , a flowchart of another motor control method for an electric vehicle provided by the embodiment of the application is shown. As shown in Figure 4 , the method mainly includes the following steps.

[0076] Step S401: determining that the VCU request torque starts to reverse.

[0077] Step S402: entering pulse width modulation.

[0078] Step S403: exiting pulse width modulation.

[0079] Specifically, when the time reaches the set holding threshold, the pulse width modulation is exited.

[0080] Step S404: determining whether the vehicle key is in the ON position.

[0081] As described above, whether the vehicle is powered on is determined by the state of the vehicle key. If yes, step S405 is performed, and if no, step S412 is performed.

[0082] Step S405: determining whether the vehicle gear is in the D / R gear.

[0083] Specifically, the D gear is the aforementioned forward gear, and the R gear is the aforementioned reverse gear. If yes, step S406 is performed, and if no, step S412 is performed.

[0084] Step S406: judging whether the motor control mode is torque control.

[0085] Specifically, if yes, step S407 is performed, and if no, step S412 is performed.

[0086] Step S407: judging whether the motor speed is greater than N1 and less than N2.

[0087] Specifically, if yes, step S409 is performed, and if no, step S408 is performed.

[0088] Step S408: judging whether the motor speed is less than N3 or greater than N4.

[0089] Specifically, if yes, step S412 is performed, and if no, step S409 is performed.

[0090] Step S409: judging whether the VCU requested torque is greater than T1 and less than T2.

[0091] Specifically, if yes, step S411 is performed, and if no, step S410 is performed.

[0092] Step S410: judging whether the VCU requested torque is less than T4 or greater than T5.

[0093] Specifically, if yes, step S412 is performed, and if no, step S411 is performed.

[0094] Step S411: entering the active tooth state to output torque with a preset torque (which can be superimposed with the anti-shake torque).

[0095] Specifically, the anti-shake torque is the above-mentioned torque compensation amount.

[0096] Step S412: exiting the active tooth state and normally responding to the VCU torque request.

[0097] The specific content involved in the embodiments of the present application can be referred to the description in the above-mentioned Figure 2 embodiments for brevity of description.

[0098] Corresponding to the above-mentioned embodiments, the present application further provides an electric vehicle motor control device.

[0099] Referring to Figure 5 , a structural schematic diagram of an electric vehicle motor control device provided by the embodiments of the present application is shown. As Figure 5 shown, the electric vehicle motor control device can include a state determination module 501 and a control module 502.

[0100] The state determining module 501 is configured to determine whether the current state is the active tooth engagement state according to the vehicle gear, the current collected motor speed, a preset speed range corresponding to the vehicle gear, and a request torque and a preset torque range corresponding to the vehicle gear, wherein the request torque is a torque in a torque control instruction sent by a vehicle controller. The control module 502 is configured to control the motor to output a preset torque if the current state is the active tooth engagement state, and control the motor to output the request torque if the current state is not the active tooth engagement state.

[0101] Corresponding to the above-mentioned embodiments, the application further provides a motor controller.

[0102] Referring to Figure 6 , a structural schematic diagram of a motor controller provided by the embodiments of the application is shown. As shown in the figure, the motor controller 600 can include a processor 601, a memory 602, and a communication unit 603. These components communicate through one or more buses, and those skilled in the art can understand that the structure of the motor controller shown in the figure does not constitute a limitation on the embodiments of the application. It can be a bus structure, or a star structure, and can include more or fewer components than shown in the figure, or combine some components, or different component arrangements. Figure 6

[0103] The communication unit 603 is configured to establish a communication channel, so that the motor controller can communicate with other devices. It receives user data sent by other devices or sends user data to other devices.

[0104] The processor 601 is the control center of the motor controller, and connects various parts of the motor controller through various interfaces and lines. It executes software programs, instructions, and / or modules stored in the memory 602, and calls data stored in the memory, to perform various functions of the motor controller and / or process data. The processor can be composed of integrated circuits (ICs), such as a single packaged IC or a plurality of packaged ICs connected together. For example, the processor 601 can only include a central processing unit (CPU). In the embodiments of the application, the CPU can be a single operation core or can include multiple operation cores.

[0105] ​The memory 602 is configured to store execution instructions of the processor 601, and the memory 602 can be implemented by any type of volatile or nonvolatile storage device or combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk or optical disk.

[0106] When the execution instructions in the memory 602 are executed by the processor 601, the motor controller 600 is enabled to perform Figure 2 part or all of the steps in the illustrated embodiments.

[0107] In specific implementations, the embodiments of the present application further provide a vehicle, which comprises Figure 6 the motor controller as illustrated.

[0108] In the embodiments of the present application, "at least one" means one or more, and "multiple" means two or more. The "and / or" describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the cases of A alone, A and B together, and B alone. Wherein A and B can be singular or plural. The character " / " generally represents an "or" relationship between the front and rear associated objects. "At least one of the following" and the like means any combination of these items, including any combination of single or multiple items. For example, at least one of a, b and c can represent: a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, and c can be single or multiple.

[0109] Those of ordinary skill in the art can realize that the units and algorithm steps described in the embodiments disclosed herein can be implemented by electronic hardware, computer software and a combination of electronic hardware and computer software. Whether the functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0110] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be described here.

[0111] In several embodiments provided in the present application, any function, if realized in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or in part or parts of the technical solutions that make contributions to the prior art can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0112] The same or similar parts among the various embodiments in the specification can be referred to each other. Especially, for the device embodiments and the terminal embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the description in the method embodiments.

Claims

1. A method for controlling an electric vehicle motor, characterized in that: include: Determining whether the current state is an active gear engagement state based on the vehicle gear, the currently acquired motor speed and a preset speed range corresponding to the vehicle gear, and the requested torque and a preset torque range corresponding to the vehicle gear, where the requested torque is the torque in the torque control command sent by the vehicle controller; If the current state is the active gear-relying state, the motor is controlled to output a preset torque; if the current state is not the active gear-relying state, the motor is controlled to output the requested torque.

2. The method according to claim 1, characterized in that The determining whether the current state is the active gear engagement state according to the vehicle gear, the currently acquired motor speed and the preset speed range corresponding to the vehicle gear, and the requested torque and the preset torque range corresponding to the vehicle gear includes: When the vehicle gear is in the forward gear, the collected motor speed is within the first preset speed range and the requested torque is within the first preset torque range, then the current state is determined to be the active gear engagement state; Alternatively, when the vehicle gear is in reverse gear, the collected motor speed is within the second preset speed range and the requested torque is within the second preset torque range, then the current state is determined to be the active gear engagement state; The first preset speed range and the second preset speed range are opposite to each other, and the first preset torque range and the second preset torque range are opposite to each other.

3. The method according to claim 2, characterized in that The method further comprises: When the vehicle gear is in the forward gear, the collected motor speed is within the third preset speed range or the fourth preset speed range, or the requested torque is within the third preset torque range or the fourth preset torque range, then the active gear engagement state is exited; Alternatively, when the vehicle gear is in reverse gear, the collected motor speed is within the fifth preset speed range or the sixth preset speed range, or the requested torque is within the fifth preset torque range or the sixth preset torque range, then the active gear engagement state is exited; Among them, the maximum value of the third preset speed range is less than the minimum value of the first preset speed range, the minimum value of the fourth preset speed range is greater than the maximum value of the first preset speed range, the fifth preset speed range and the third preset speed range are inverse intervals of each other, and the sixth preset speed range and the fourth preset speed range are inverse intervals of each other; the maximum value of the third preset torque range is less than the minimum value of the first preset torque range, the minimum value of the fourth preset torque range is greater than the maximum value of the first preset torque range, the fifth preset torque range and the third preset torque range are inverse intervals of each other, and the sixth preset torque range and the fourth preset torque range are inverse intervals of each other.

4. The method according to claim 1, wherein The determining whether the current state is the active gear engagement state according to the vehicle gear, the currently acquired motor speed and the preset speed range corresponding to the vehicle gear, and the requested torque and the preset torque range corresponding to the vehicle gear includes: If the vehicle is powered on and the gear is in forward gear or reverse gear and the current motor control mode is torque control, then determine whether the current state is the active gear engagement state based on the vehicle gear, the currently collected motor speed and the preset speed range corresponding to the vehicle gear, and the requested torque and the preset torque range corresponding to the vehicle gear; If any of the following conditions is not met: the vehicle is powered on, the vehicle gear is in the forward gear or the reverse gear, and the current motor control mode is torque control, the motor is controlled to output the requested torque.

5. The method according to claim 1, wherein The method further comprises: Determine the speed fluctuation amount and the speed fluctuation node according to the speed before filtering and the speed after filtering; calculating a torque compensation amount according to the speed fluctuation amount, wherein an adjustment direction of the torque compensation amount is opposite to a change direction of the speed fluctuation amount; At the rotation speed fluctuation node, the torque compensation amount is output.

6. The method according to claim 1, characterized in that The method further comprises: When the motor torque changes from negative to positive, the initial motor speed is stored; Convert the motor control mode to speed control; According to the target speed, a motor speed control signal is output. The target speed is the sum of the initial motor speed and the preset relative speed. The motor speed control signal is used to control the driving gear of the motor to output the target speed.

7. The method according to claim 6, characterized in that The method further comprises: When the motor speed control signal output reaches a preset time, the motor control is prevented from being converted into torque control; According to the current motor torque and the requested torque, a motor torque control signal is outputted so that the motor torque quickly approaches the requested torque.

8. An electric vehicle motor control device, characterized in that: include: a state determination module, configured to determine whether the current state is an active gear engagement state based on the vehicle gear position, the currently acquired motor speed and a preset speed range corresponding to the vehicle gear position, and the requested torque and a preset torque range corresponding to the vehicle gear position, wherein the requested torque is the torque in the torque control command sent by the vehicle controller; The control module is used to control the motor to output a preset torque if the current state is an active gear-engaging state; and to control the motor to output the requested torque if the current state is not an active gear-engaging state.

9. A motor controller, characterized in that: include: processor; Memory; and a computer program, wherein the computer program is stored in the memory, the computer program comprising instructions, which, when executed by the processor, cause the motor controller to perform the method according to any one of claims 1 to 7.

10. A vehicle, characterized in that: The vehicle includes the motor controller of claim 9.

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