Gear gap bite torque control method and system

Abstract

This invention discloses a method and system for controlling gear backlash and meshing torque. The method obtains the motor's rotational speed at the current moment; inputs the rotational speed as a setpoint to a speed loop PI controller, and periodically adjusts the setpoint to obtain a corresponding speed loop feedback torque; superimposes the speed loop feedback torque with a pre-calibrated torque to obtain a control torque, wherein the pre-calibrated torque is the torque value corresponding to the current moment in the torque curve obtained from pre-calibrated vehicle calibration; based on the control torque, the motor gears are controlled to mesh. It can be seen that this invention can accurately find a suitable torque based on a pre-calibrated torque curve, and form a control torque through closed-loop control based on the speed loop feedback torque. Then, the motor operation is controlled based on the control torque to achieve gear meshing, effectively solving gear tooth noise and gear tooth vibration, with ideal suppression effect.

Description

Technical Field

[0001] This invention relates to the field of motor control, and in particular to a method and system for controlling gear backlash engagement torque. Background Technology

[0002] Currently, electric vehicles are developing rapidly. Generally, the powertrain of an electric vehicle consists of a motor connected via a drive shaft, drive gears, and driven gears. Due to the gap between the drive and driven gears, abnormal noises and vibrations can occur when releasing the accelerator, pressing the accelerator, starting the vehicle, and braking, affecting the driving experience. Currently, open-loop control strategies are generally used to suppress these noises and vibrations, but these methods are not effective in completely eliminating them, and the suppression effect is unsatisfactory. Summary of the Invention

[0003] In view of the above problems, the present invention provides a gear backlash engagement torque control method and system that overcomes or at least partially solves the above problems.

[0004] In a first aspect, a method for controlling gear backlash engagement torque includes:

[0005] Obtain the motor's rotational speed at the current moment;

[0006] The rotational speed is input as a given value to the speed loop PI controller, and the given value is periodically adjusted to obtain the corresponding speed loop feedback torque.

[0007] The control torque is obtained by superimposing the speed loop feedback torque with the corresponding pre-calibrated torque, wherein the pre-calibrated torque is the torque value corresponding to the current moment in the torque curve obtained by pre-calibrating the whole vehicle;

[0008] Based on the control torque, the gears of the motor are controlled to mesh.

[0009] Optionally, in some optional embodiments, the vehicle calibration process for the torque curve includes:

[0010] The motor is powered on for the first time to obtain the minimum torque that makes the motor rotate;

[0011] A second power supply is supplied to the motor, and the motor is controlled to start from a stationary state and gradually increase the torque of the motor by increasing the step size by at least one torque value until the initial torque of tooth engagement and the target required torque are reached, thereby completing the calibration of the first stage curve. The initial torque of tooth engagement is equal to the minimum torque, and the target required torque is greater than the minimum torque.

[0012] Stop supplying power to the motor for the second time, and control the motor to gradually reduce the torque of the motor from the target required torque by a decreasing step size of at least one torque value until the tooth-stopping torque is reached, thereby completing the calibration of the first part of the second stage curve, wherein the tooth-stopping torque is equal to the minimum torque;

[0013] The motor is controlled to gradually reduce its torque to zero starting from the point where the tooth ends, with a preset torque value decreasing in step size, thereby completing the calibration of the latter part of the second stage curve;

[0014] Starting from the point where the torque of the motor decreases to zero, the torque of the motor is gradually reduced to negative torque by decreasing the step size by at least one torque value, thereby completing the calibration of the third-stage curve;

[0015] The motor is powered on for the third time, and the motor is controlled to gradually increase its torque to zero torque, starting from the negative torque and increasing the torque step by at least one torque value, thereby completing the calibration of the fourth stage curve.

[0016] The torque curve is obtained based on the first stage curve, the second stage curve, the third stage curve, and the fourth stage curve.

[0017] Optionally, in some alternative embodiments, the initial supply of power to the motor to obtain the minimum torque required to rotate the motor includes:

[0018] The first power supply is provided to the motor;

[0019] The minimum torque required to rotate the motor is obtained by reading the vehicle's overall message.

[0020] Optionally, in some optional embodiments, the second power supply to the motor, controlling the motor to start from a stationary state and gradually increase the motor torque to the starting torque and target required torque by increasing the torque step by at least one torque value, thereby completing the calibration of the first stage curve, includes:

[0021] A second power supply is provided to the motor;

[0022] Starting from the stationary state, the motor is controlled to gradually increase its torque to the initial torque of the tooth engagement step by step, starting with a first torque value;

[0023] The torque of the motor is controlled to gradually increase from the initial torque of the toothed motor to the target required torque by increasing the step size by at least one torque value, thereby completing the calibration of the first stage curve, wherein each of the increasing step sizes increases sequentially.

[0024] Optionally, in some optional embodiments, the step of controlling the motor torque to gradually increase from the initial gear torque to the target required torque by increasing the step size by at least one torque value, thereby completing the calibration of the first-stage curve, includes:

[0025] The second torque value is used to increase the step size, and the torque of the motor is controlled to increase continuously from the initial torque of the tooth according to a preset cycle for a first time length.

[0026] After the torque of the motor continues to increase for the first time length, the torque of the motor continues to increase for the second time length according to the preset period by increasing the step size by the third torque value, wherein the third torque value is greater than the second torque value;

[0027] After the torque of the motor continues to increase for the second time length, the torque is increased by a fourth torque value in increments, and the torque of the motor continues to increase for a third time length according to the preset cycle. This process is repeated until the torque of the motor increases to the target required torque, thereby completing the calibration of the first stage curve. The fourth torque value is greater than the third torque value.

[0028] Optionally, in some alternative implementations, the method further includes:

[0029] During the first time period during which the torque of the motor continues to increase: the gears of the motor engage.

[0030] Optionally, in some alternative implementations, stopping the second power supply to the motor and controlling the motor to gradually reduce the motor torque from the target required torque by at least one torque value in decreasing steps until the gear termination torque is reached, thereby completing the calibration of the first segment of the second-stage curve, includes:

[0031] Stop supplying power to the motor for the second time;

[0032] Using the fifth torque value as the decreasing step size, and according to a preset cycle, the torque of the motor is controlled to continuously decrease from the target required torque for a fourth time period.

[0033] After the torque of the motor continues to decrease for the fourth time length, the torque of the motor continues to decrease for the fifth time length according to the preset period, with a sixth torque value as the reduction step, wherein the sixth torque value is less than the fifth torque value;

[0034] After the torque of the motor continues to decrease for the fifth time length, the torque of the motor continues to decrease for the sixth time length according to the preset cycle, with the seventh torque value as the reduction step. This continues until the torque of the motor decreases to the tooth-stopping torque, thereby completing the calibration of the first segment of the second stage curve. The seventh torque value is less than the sixth torque value.

[0035] Optionally, in some alternative embodiments, controlling the motor to gradually reduce its torque to negative torque, starting from the point of zero torque, by decreasing the torque by at least one torque value in decreasing steps, thereby completing the calibration of the third-stage curve, includes:

[0036] Starting from the point where the motor torque is reduced to zero, the torque of the motor is gradually reduced to the negative torque by at least one torque value as a decreasing step, thereby completing the calibration of the third stage curve. The decreasing steps are increased sequentially. During the period when the torque of the motor is gradually reduced to the negative torque, the gears of the motor engage.

[0037] Optionally, in some optional embodiments, the calibration of the third-stage curve, starting from the zero torque of the motor and gradually reducing the torque of the motor to the negative torque by at least one torque value as a decreasing step, to complete the calibration, includes:

[0038] Starting from the point where the motor torque decreases to zero, the torque of the motor is controlled to decrease continuously for a seventh time period, with the eighth torque value as the decreasing step size, according to a preset cycle.

[0039] After the torque of the motor continues to decrease for the seventh time length, the torque of the motor continues to decrease for the eighth time length according to the preset period, with the ninth torque value as the decrease step. The ninth torque value is greater than the eighth torque value.

[0040] After the torque of the motor continues to decrease for the eighth time length, the torque of the motor continues to decrease for the ninth time length according to the preset cycle, with the tenth torque value as the reduction step. This process is repeated until the torque of the motor is reduced to a preset negative torque, thereby completing the calibration of the third stage curve. The tenth torque value is greater than the ninth torque value.

[0041] Optionally, in some alternative embodiments, the third power supply to the motor, controlling the motor to gradually increase its torque from the negative torque stage to the zero torque stage by increments of at least one torque value, thereby completing the calibration of the fourth-stage curve, includes:

[0042] The motor is supplied with power for the third time, starting from the negative torque, and the torque of the motor is gradually increased to the zero torque by increasing the step size by at least one torque value, thereby completing the calibration of the fourth stage curve, wherein the increment step size decreases sequentially.

[0043] Optionally, in some alternative embodiments, the third power supply to the motor, starting from the negative torque, gradually increases the motor torque to the zero torque by increments of at least one torque value, thereby completing the calibration of the fourth-stage curve, includes:

[0044] The third power supply is then provided to the motor;

[0045] Starting from the negative torque, the torque of the motor is controlled to increase by a step size of eleventh torque value according to a preset cycle, starting from the negative torque and continuously increasing for tenth time length.

[0046] After the torque of the motor continues to increase for the tenth time length, the torque of the motor is controlled to continue to increase for the eleventh time length according to a preset period, with the twelfth torque value being less than the eleventh torque value.

[0047] After the torque of the motor continues to increase for the eleventh time length, the step size is increased by the thirteenth torque value. According to the preset cycle, the torque of the motor is controlled to continue to increase for the twelfth time length, and so on, until the torque of the motor increases to the zero torque, thereby completing the calibration of the fourth stage curve, wherein the thirteenth torque value is less than the twelfth torque value.

[0048] Optionally, in some optional embodiments, obtaining the torque curve based on the first stage curve, the second stage curve, the third stage curve, and the fourth stage curve includes:

[0049] The first stage curve and the second stage curve are merged and spliced ​​together end to end;

[0050] The second-stage curve is merged and spliced ​​with the third-stage curve;

[0051] The third-stage curve and the fourth-stage curve are merged and spliced ​​together to obtain the torque curve.

[0052] Optionally, in some alternative implementations, obtaining the motor's rotational speed at the current moment includes:

[0053] When the torque step size executed by the motor at the current moment is within the preset step size range, the rotational speed of the motor at the current moment is collected, wherein the torque step size is an increasing step size or a decreasing step size.

[0054] Optionally, in some optional embodiments, the step of inputting the rotational speed as a given value to the speed loop PI controller and periodically adjusting the given value to obtain the corresponding speed loop feedback torque includes:

[0055] The rotational speed is input as a given value to the speed loop PI controller;

[0056] Based on the difference between the speed loop feedback torque output by the speed loop PI controller based on the rotational speed and the preset feedback torque, the adjustment step size for adjusting the input to the given value of the speed loop PI controller is determined;

[0057] According to the adjustment step size, the input to the given value of the speed loop PI controller is gradually increased until the difference between the speed loop feedback torque output by the speed loop PI controller and the preset feedback torque meets the preset condition.

[0058] Optionally, in some optional embodiments, determining the adjustment step size for adjusting the given value input to the speed loop PI controller based on the difference between the speed loop feedback torque output by the speed loop PI controller based on the rotational speed and a preset feedback torque includes:

[0059] If the difference between the speed loop feedback torque output by the speed loop PI controller based on the rotational speed and the preset feedback torque is greater than a first difference threshold, then the adjustment step size is determined to be the first adjustment step size.

[0060] If the difference between the speed loop feedback torque output by the speed loop PI controller based on the rotational speed and the preset feedback torque is not greater than the first difference threshold, then the adjustment step size is determined to be the second adjustment step size, wherein the second adjustment step size is smaller than the first adjustment step size.

[0061] Optionally, in some alternative embodiments, after the difference between the speed loop feedback torque output by the speed loop PI controller and the preset feedback torque satisfies the preset condition, the method further includes:

[0062] If the speed loop feedback torque output by the speed loop PI controller is greater than the preset upper limit threshold, then the final obtained speed loop feedback torque is determined to be the preset upper limit threshold.

[0063] If the speed loop feedback torque output by the speed loop PI controller is less than the preset lower threshold, then the final speed loop feedback torque is determined to be the preset lower threshold.

[0064] If the speed loop feedback torque output by the speed loop PI controller is not greater than the preset upper limit threshold and not less than the preset lower limit threshold, then the final obtained speed loop feedback torque is determined to be the speed loop feedback torque output by the speed loop PI controller.

[0065] Optionally, in some alternative implementations, after determining the final obtained speed loop feedback torque, the method further includes:

[0066] Calculate the torque difference between the speed loop feedback torque output by the speed loop PI controller and the final obtained speed loop feedback torque;

[0067] The torque difference is processed by an anti-saturation function and then multiplied by a preset anti-saturation coefficient. The resulting product is used as the negative feedback of the speed loop PI controller.

[0068] Optionally, in some optional embodiments, the step of superimposing the speed loop feedback torque with a corresponding pre-calibrated torque to obtain the control torque includes:

[0069] The control torque is obtained by adding the speed loop feedback torque to the corresponding pre-calibrated torque.

[0070] Optionally, in some alternative embodiments, after adding the speed loop feedback torque to the corresponding pre-calibrated torque to obtain the control torque, the method further includes:

[0071] If the control torque is greater than the preset speed loop exit threshold, then the final speed loop feedback torque is determined to be zero, wherein the speed loop exit threshold is obtained by pre-calibration.

[0072] Optionally, in some optional implementations, the calibration process for the velocity loop exit threshold includes:

[0073] The speed loop exit threshold is set to K times the peak torque of the motor, where K is greater than 0 and less than 1.

[0074] When the control torque is equal to the set value, if the vibration amplitude of the motor speed is within the preset amplitude range, then the set value is determined as the speed loop exit threshold.

[0075] If the vibration amplitude of the motor speed is not within the preset amplitude range, the setting value is increased, and when the control torque is equal to the setting value, it is determined again whether the vibration amplitude of the motor speed is within the preset amplitude range. This process is repeated until the speed loop exit threshold is determined.

[0076] Optionally, in some alternative embodiments, controlling the gears of the motor to mesh based on the control torque includes:

[0077] Based on the control torque, the corresponding pre-calibrated table is consulted to obtain the corresponding motor DQ axis current;

[0078] The operation of the motor is controlled based on the DQ axis current of the motor, so that the gears of the motor mesh.

[0079] Optionally, in some alternative embodiments, the step of querying a pre-calibrated table based on the control torque to obtain the corresponding motor DQ shaft current includes:

[0080] If the control torque is within the preset small torque range, the corresponding pre-calibrated first table is consulted to obtain the corresponding motor DQ axis current. The lookup torque step size of the first table is N times the normal torque step size, which is equal to M times the maximum peak torque of the motor. Both N and M are greater than 0 and less than 1.

[0081] Optionally, in some alternative embodiments, the step of querying a pre-calibrated table based on the control torque to obtain the corresponding motor DQ shaft current includes:

[0082] If the control torque is outside the preset small torque range, the corresponding pre-calibrated second table is consulted to obtain the corresponding motor DQ axis current. The lookup torque step size of the second table is the normal torque step size, which is equal to M times the maximum peak torque of the motor, where M is greater than 0 and less than 1.

[0083] Secondly, a gear backlash engagement torque control system includes: a motor, a speed loop torque node, a torque superposition node, and a variable PI control current loop;

[0084] The motor is connected to the speed loop torque node, the speed loop torque node is connected to the torque superposition node, and the torque superposition node is connected to the variable PI control current loop;

[0085] The speed loop torque node is used to obtain the motor speed at the current moment;

[0086] The speed loop torque node is used to input the rotational speed as a given value to the speed loop PI controller and periodically adjust the given value to obtain the corresponding speed loop feedback torque.

[0087] The torque superposition node is used to superimpose the speed loop feedback torque with the corresponding pre-calibrated torque to obtain the control torque, wherein the pre-calibrated torque is the torque value corresponding to the current moment in the torque curve obtained by pre-calibrating the whole vehicle.

[0088] The variable PI control current loop is used to control the gears of the motor to mesh based on the control torque.

[0089] By employing the above technical solution, the present invention provides a gear backlash meshing torque control method and system, which can obtain the motor's rotational speed at the current moment; input the rotational speed as a setpoint to a speed loop PI controller, and periodically adjust the setpoint to obtain the corresponding speed loop feedback torque; superimpose the speed loop feedback torque with a pre-calibrated torque to obtain the control torque, wherein the pre-calibrated torque is the torque value corresponding to the current moment in the torque curve obtained by pre-calibrating the entire vehicle; based on the control torque, control the motor gears to achieve meshing. It can be seen that the present invention can accurately find a suitable torque based on a pre-calibrated torque curve, and form a control torque through closed-loop control based on the speed loop feedback torque, and then control the motor operation based on the control torque to achieve gear meshing, effectively solving gear tooth noise and gear tooth vibration, with a relatively ideal suppression effect.

[0090] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0091] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0092] Figure 1 A flowchart of a gear backlash engagement torque control method provided by the present invention is shown;

[0093] Figure 2 A schematic diagram of a speed loop PI controller provided by the present invention is shown;

[0094] Figure 3 A flowchart of a strategy for varying PI coefficients provided by the present invention is shown;

[0095] Figure 4A flowchart illustrating the vehicle calibration process for a torque curve provided by the present invention is shown.

[0096] Figure 5 A schematic diagram of a gear backlash torque control system provided by the present invention is shown.

[0097] Figure 6 A schematic diagram of the structure of an electronic device provided by the present invention is shown. Detailed Implementation

[0098] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0099] like Figure 1 As shown, the present invention provides a method for controlling gear backlash engagement torque, including: S100, S200, and S300;

[0100] S100: Obtain the motor speed at the current moment;

[0101] Optionally, the motor mentioned in this invention can be a motor located in an electric vehicle. The executing entity of this invention can obtain the corresponding rotational speed during motor operation. For example, this invention can acquire vehicle messages (carrying motor rotational speed signals) based on a CAN bus (also known as a CANBUS analyzer) or obtain the motor rotational speed signal during vehicle operation based on other related devices, and then calculate the rotational speed corresponding to the rotational speed signal.

[0102] Optionally, in some alternative implementations, S100 includes:

[0103] When the torque step size executed by the motor at the current moment is within the preset step size range, the rotational speed of the motor at the current moment is collected, wherein the torque step size is an increasing step size or a decreasing step size.

[0104] Optionally, this invention implements gear engagement of the vehicle's motor. In practice, gear engagement is typically required when releasing the accelerator or suddenly pressing the accelerator. That is, this invention can determine the range of torque step lengths when releasing the accelerator and suddenly pressing the accelerator through calibration, and use this range as a preset step length range. When the torque step length acquired at the current moment is within the preset step length range, it indicates that the vehicle is in the stage of releasing or suddenly pressing the accelerator, requiring subsequent control to achieve gear engagement. Therefore, this invention can acquire the current rotational speed for subsequent processes.

[0105] S200. The rotational speed is input as a given value to the speed loop PI controller, and the given value is periodically adjusted to obtain the corresponding speed loop feedback torque.

[0106] Optionally, the speed loop PI controller described in this invention is an improvement on the PI controller, and its principle is as follows: Figure 2 As shown. Where K P K represents the proportionality coefficient. i K represents the integral coefficient. a E represents the anti-saturation coefficient. rr This represents the difference between the setpoint and the feedback value of the PI controller.

[0107] Optionally, the PI controller (also known as a proportional-integral controller) is a well-known concept in the art, and this invention will not describe it in detail; please refer to relevant descriptions in the art for specific details. It should be noted that the calibration scheme for the proportional-integral coefficients of the PI controller is as follows:

[0108] Based on the analysis of the vehicle's message data, the amplitude and frequency of the speed vibration are determined. First, the proportional coefficient of the PI controller is increased, and the amplitude of the speed vibration is observed to decrease. If it decreases, the proportional coefficient is increased until the amplitude of the speed vibration remains almost constant. If the amplitude of the speed vibration remains almost constant, the proportional coefficient is maintained. Then, the integral coefficient is increased until the amplitude of the speed vibration does not decrease after a few steps. At this point, it indicates that the calibration of the proportional-integral coefficient of the PI controller has been completed.

[0109] Optionally, due to the inherent characteristics of PI controllers, using a large PI coefficient can lead to overshoot, causing overcurrent in the motor controller and, in severe cases, even causing the switching transistor to explode. However, a smaller PI coefficient will result in poorer current tracking performance and a slower dynamic response. A slower dynamic response leads to a slower torque response, especially when the torque is low, as the difference between the current setpoint and the feedback value is small, resulting in an even slower current dynamic response. Generally, to avoid overcurrent faults when the current is high, a smaller PI coefficient is chosen, sacrificing some torque response speed.

[0110] Based on the above analysis, the tooth engagement stage is the stage where the motor's torque is relatively small (preset small torque range), resulting in a slower dynamic torque response, which further affects the acceleration performance when the accelerator is pressed and the energy feedback performance when the accelerator is released. In summary, this invention proposes a variable PI coefficient strategy during the tooth engagement stage. That is, when the motor is executing a small torque, the motor current is relatively small, and using a larger PI coefficient will not cause overcurrent problems; while when the current is relatively large, a smaller PI coefficient is used to solve the overcurrent problem when the current is large. For details, please refer to... Figure 3 The flowchart shows the strategy of varying PI coefficients.

[0111] Depend on Figure 3 It can be seen that the strategy of varying the PI coefficient is as follows: when the motor's operating torque is below a certain initial torque threshold, a larger PI coefficient is selected; when the motor's operating torque is between the initial torque threshold and the termination torque threshold, a linear transition is used to switch to a smaller PI coefficient; when the motor's operating torque is above the termination torque threshold, a smaller PI coefficient is selected. Generally, the initial torque threshold is smaller than the termination torque threshold. The selection of the initial torque threshold and the termination torque threshold can be obtained from the vehicle calibration, while the larger and smaller PI coefficients can be selected based on the results of the motor bench calibration.

[0112] Optionally, the present invention does not specifically limit the process of obtaining the corresponding speed loop feedback torque, and any feasible method is within the protection scope of the present invention. For example, in some optional embodiments, step S200 includes: steps 2.1, 2.2, and 2.3;

[0113] Step 2.1: Input the rotational speed as a given value to the speed loop PI controller;

[0114] Optionally, as mentioned above, the speed loop PI controller can make the feedback value follow the setpoint, thus effectively controlling the motor speed and suppressing speed fluctuations. Therefore, this invention can input the collected speed as the setpoint to the speed loop PI controller. It should be noted that setpoint and feedback values ​​are well-known concepts in the art, and this invention will not elaborate on them further; please refer to relevant descriptions in the art for details.

[0115] Step 2.2: Based on the difference between the speed loop feedback torque output by the speed loop PI controller based on the rotational speed and the preset feedback torque, determine the adjustment step size for adjusting the input to the given value of the speed loop PI controller;

[0116] Optionally, the speed loop PI controller can obtain the corresponding speed loop feedback torque after processing based on the rotational speed. Therefore, this invention can calculate the difference between the speed loop feedback torque and the preset feedback torque, and then adjust the adjustment step size of the given value according to the difference.

[0117] For example, in some alternative implementations, step 2.2 includes: steps 2.21 and 2.22;

[0118] Step 2.21: If the difference between the speed loop feedback torque output by the speed loop PI controller based on the rotational speed and the preset feedback torque is greater than the first difference threshold, then the adjustment step size is determined to be the first adjustment step size;

[0119] Step 2.22: If the difference between the speed loop feedback torque output by the speed loop PI controller based on the rotational speed and the preset feedback torque is not greater than the first difference threshold, then the adjustment step size is determined to be the second adjustment step size, wherein the second adjustment step size is smaller than the first adjustment step size.

[0120] Step 2.3: According to the adjustment step size, gradually increase the input to the given value of the speed loop PI controller until the difference between the speed loop feedback torque output by the speed loop PI controller and the preset feedback torque meets the preset condition.

[0121] Optionally, the given value mentioned in this invention can be increased slowly according to the adjustment step size. If the difference between the above torques is large (greater than the first difference threshold), the given value is increased by a larger step size (first adjustment step size); if the difference is small (not greater than the first difference threshold), the given value is increased by a smaller step size (second adjustment step size). This invention does not limit this.

[0122] Optionally, when the torque difference mentioned above is less than a certain threshold, such as less than a second difference threshold, it indicates that the speed loop feedback torque output by the speed loop PI controller is close to the preset feedback torque. Therefore, the present invention may not increase the given value or may decrease the given value by a certain step size, and the present invention does not limit this.

[0123] Optionally, when the difference between the speed loop feedback torque and the preset feedback torque is less than a certain threshold, it indicates that the preset condition has been met. In this case, the obtained adjustment step size can be used as the corresponding calibration value, and this invention does not impose any limitations on this.

[0124] Optionally, to further effectively suppress gear noise, reduce vibration, and improve overall vehicle comfort, this invention can limit the output speed loop feedback torque.

[0125] For example, in some optional embodiments, after the difference between the speed loop feedback torque output by the speed loop PI controller in step 2.3 and the preset feedback torque meets the preset condition, the method further includes steps 3.1, 3.2 and 3.3;

[0126] Step 3.1: If the speed loop feedback torque output by the speed loop PI controller is greater than the preset upper limit threshold, then the final obtained speed loop feedback torque is determined to be the preset upper limit threshold.

[0127] Step 3.2: If the speed loop feedback torque output by the speed loop PI controller is less than the preset lower threshold, then the final obtained speed loop feedback torque is determined to be the preset lower threshold.

[0128] Step 3.3: If the speed loop feedback torque output by the speed loop PI controller is not greater than the preset upper limit threshold and not less than the preset lower limit threshold, then the final obtained speed loop feedback torque is determined to be the speed loop feedback torque output by the speed loop PI controller.

[0129] Optionally, the aforementioned preset upper and lower threshold values ​​can be obtained through calibration. For example, the preset upper threshold value can be "A" and the preset lower threshold value can be "-A" through calibration; this invention does not impose any limitations on this.

[0130] Optionally, when the speed loop feedback torque is greater than A, the final output speed loop feedback torque is A; when the speed loop feedback torque is less than -A, the final output speed loop feedback torque is -A; when the speed loop feedback torque is neither greater than A nor less than -A, the final output speed loop feedback torque is the corresponding actual speed loop feedback torque. This invention does not impose any limitations on this.

[0131] Optionally, in some alternative implementations, after determining the final speed loop feedback torque, the method further includes steps 4.1 and 4.2;

[0132] Step 4.1: Calculate the torque difference between the speed loop feedback torque output by the speed loop PI controller and the torque of the final obtained speed loop feedback torque;

[0133] Step 4.2: After the torque difference is processed by the anti-saturation function, it is multiplied by the preset anti-saturation coefficient, and the product is used as the negative feedback of the speed loop PI controller.

[0134] Optional, please see Figure 2 This invention can calculate the error values ​​of X and Y and e. rr The error between the values; then adjust K a When the error between two values ​​is not significant, increase K. a The value of X is rapidly reduced, causing the PI controller to desaturate quickly, and the desaturation time meets a certain allowable time threshold.

[0135] After the above-mentioned anti-saturation control, the overshoot of the current motor speed can be effectively reduced, the motor speed can be controlled more accurately, and the effect of suppressing gear noise can be increased. Therefore, after adding speed loop compensation torque, this invention can also effectively increase the vehicle's acceleration performance and energy recovery performance to increase the vehicle's range.

[0136] S300. The speed loop feedback torque is superimposed with the corresponding pre-calibrated torque to obtain the control torque, wherein the pre-calibrated torque is the torque value corresponding to the current moment in the torque curve obtained by pre-calibrating the whole vehicle.

[0137] Optionally, the horizontal axis of the torque curve in this invention can be time, and the vertical axis can be torque. The corresponding torque can be found from the torque curve by the current time in S100. This invention does not limit this.

[0138] Optionally, the present invention does not limit the method of superimposing torque as described above. For example, in some optional embodiments, S300 includes: adding the speed loop feedback torque to the corresponding pre-calibrated torque to obtain the control torque.

[0139] Optionally, in some alternative embodiments, after adding the speed loop feedback torque to the corresponding pre-calibrated torque to obtain the control torque, the method further includes:

[0140] If the control torque is greater than the preset speed loop exit threshold, then the final speed loop feedback torque is determined to be zero, wherein the speed loop exit threshold is obtained by pre-calibration.

[0141] Optionally, in some optional embodiments, the calibration process of the speed loop exit threshold includes: steps 5.1 and 5.2;

[0142] The speed loop exit threshold is set to K times the peak torque of the motor, where K is greater than 0 and less than 1.

[0143] Step 5.1: When the control torque is equal to the set value, if the speed vibration amplitude of the motor is within the preset amplitude range, then the set value is determined as the speed loop exit threshold.

[0144] Step 5.2: If the vibration amplitude of the motor speed is not within the preset amplitude range, increase the setting value, and when the control torque is equal to the setting value, determine again whether the vibration amplitude of the motor speed is within the preset amplitude range. Repeat this cycle until the speed loop exit threshold is determined.

[0145] Optionally, in addition to this, the present invention can also be set to exit the speed loop feedback after the speed loop feedback torque is continuously superimposed with the corresponding pre-calibrated torque for a certain period of time. That is, the speed loop feedback torque is controlled to zero.

[0146] Optionally, the torque mentioned in this invention can be positive torque, zero torque, or negative torque. When adding the torques, they can be added in a mathematical manner.

[0147] Optionally, this invention does not impose specific limitations on the vehicle calibration process for the torque curve; any feasible method falls within the scope of protection of this invention. For example, such as... Figure 4As shown, in some optional embodiments, the vehicle calibration process of the torque curve includes: S1000, S2000, S3000, S4000, S5000, S6000 and S7000.

[0148] S1000: Supply power to the motor for the first time to obtain the minimum torque that makes the motor rotate;

[0149] Optionally, the present invention can first supply power to the motor of the vehicle in a stationary state, and collect the minimum torque required to change the motor from a stationary state to a rotating state. Specifically, the present invention can obtain the aforementioned minimum torque by acquiring vehicle messages and then analyzing the vehicle messages.

[0150] That is, in some optional implementations, S1000 includes: steps 6.1 and 6.2;

[0151] Step 6.1: Provide the motor with the first power supply;

[0152] Step 6.2: Obtain the minimum torque required to rotate the motor by reading the vehicle's overall message.

[0153] It should be noted that, from the perspective of the entire vehicle, this invention can supply power to the motor by pressing the accelerator pedal (which can also be understood as the ignition switch), and completely releasing the accelerator pedal can be understood as disconnecting the power supply. Therefore, this invention does not limit the depth of pressing the accelerator pedal during the initial power supply; it can be fully depressed or lightly depressed, as long as it is pressed to a certain depth.

[0154] Optionally, after the minimum torque is detected, the present invention can disconnect the first power supply to facilitate the subsequent second power supply.

[0155] S2000: Power the motor a second time, control the motor to start from a stationary state, and gradually increase the torque of the motor to the starting torque of tooth engagement and the target required torque by increasing the step size by at least one torque value, thereby completing the calibration of the first stage curve, wherein the starting torque of tooth engagement is equal to the minimum torque, and the target required torque is greater than the minimum torque;

[0156] Optionally, the motor can also start from a standstill during the second power supply. That is, it can start from a state where the motor is not rotating.

[0157] Optionally, during the calibration of the first-stage curve, the motor torque needs to be gradually increased, but the step size (increase step size) can be the same or different each time.

[0158] Optionally, the target torque requirement mentioned in this invention can be understood as the torque required by the driver. Specifically, this invention can calculate the target torque requirement based on throttle depth, or it can directly obtain the target torque requirement from other systems; this invention does not impose any limitations on this.

[0159] For example, in some optional implementations, S2000 includes: steps 7.1, 7.2, and 7.3;

[0160] Step 7.1: Provide a second power supply to the motor;

[0161] Step 7.2: Starting from the stationary state, control the motor to gradually increase the torque of the motor to the starting torque of the tooth engagement by increasing the step size by the first torque value;

[0162] Optionally, this invention does not impose a specific limitation on the time taken to gradually increase the motor torque to the initial torque of the tooth contact by increasing the step size with a first torque value. The specific time depends on the magnitude of the initial torque of the tooth contact and the magnitude of the first torque value, and this invention does not impose any limitations on this.

[0163] Optionally, the first torque value is obtained based on the vehicle calibration. The basic rule for selecting the first torque value is that it needs to meet the power requirements of the vehicle when the accelerator is pressed.

[0164] Step 7.3: By increasing the step size by at least one torque value, control the torque of the motor to gradually increase from the initial torque of the toothed motor to the target required torque, thereby completing the calibration of the first stage curve;

[0165] The step size increases sequentially for each step.

[0166] Optionally, the present invention does not impose specific limitations on the time taken for the motor torque to gradually increase from the initial torque at the tooth-mounted position to the target required torque by increasing the step size by at least one torque value.

[0167] Optionally, if the process of gradually increasing the motor torque from the initial torque near the teeth to the target torque uses multiple increment steps, then each increment step increases sequentially in chronological order. Of course, the increment steps do not necessarily have to be sequentially increasing. For example, the increment steps can be in a relationship of both increasing and decreasing. For instance, several consecutive increment steps may be sequentially increasing, followed by at least one subsequent increment step that is sequentially decreasing. That is, each increment step can be larger or smaller than the previous increment step, and this invention does not impose any restrictions on this.

[0168] For example, in some alternative implementations, step 7.3 includes: steps 8.1, 8.2, and 8.3;

[0169] Step 8.1: Increasing the step size by the second torque value, and controlling the torque of the motor to continuously increase the first time length from the starting torque of the tooth according to the preset cycle;

[0170] Optionally, the second torque value can be greater than, equal to, or less than the first torque value. Generally, the second torque value is less than the first torque value; this invention does not impose any limitation on this. It should be noted that the second torque value and the first time length are obtained through vehicle calibration, and they basically need to ensure that gear noise is within an acceptable range, while the power performance meets the requirements. Through repeated adjustments, the vehicle is brought to a relatively good state, where both power performance and gear noise requirements are met.

[0171] Optionally, this invention does not impose specific limitations on the preset period; any feasible method falls within the scope of protection of this invention. For example, if the preset period is 1 millisecond, then the motor torque is increased once every 1 millisecond, with each increase in torque being a second torque value. If the first time length is 10 milliseconds, then the motor torque is increased 10 times during the first time length, each time increasing by a first torque value. It should be noted that the preset period described in this invention applies to all increase and decrease step sizes. That is, different increase and decrease step sizes all use the same preset period.

[0172] Optionally, in some alternative implementations, the method further includes:

[0173] During the first time period during which the torque of the motor continues to increase: the gears of the motor engage.

[0174] It should be noted that during the initial period of continuous increase in motor torque, the motor's driving teeth can move forward and engage with the driven teeth.

[0175] Step 8.2: After the torque of the motor continues to increase for the first time length, the torque of the motor continues to increase for the second time length according to the preset period by increasing the step size by the third torque value, wherein the third torque value is greater than the second torque value;

[0176] Optionally, for step 8.2, please refer to the foregoing explanation for analogy; the present invention will not elaborate further on this.

[0177] Step 8.3: After the torque of the motor continues to increase for the second time length, the fourth torque value is used as the step size, and the torque of the motor is controlled to continue to increase for the third time length according to the preset cycle, and so on, until the torque of the motor increases to the target required torque, thereby completing the calibration of the first stage curve, wherein the fourth torque value is greater than the third torque value.

[0178] Optionally, before the motor torque increases to the target required torque, the present invention may use any number of different torque values ​​as the increment step, and the present invention does not limit this.

[0179] S3000, Stop supplying power to the motor for the second time, and control the motor to gradually reduce the torque of the motor from the target required torque by at least one torque value in decreasing step size until the tooth-end torque is reached, thereby completing the calibration of the first part of the second stage curve;

[0180] Wherein, the tooth-stopping torque is equal to the minimum torque;

[0181] Optionally, the endpoint of the aforementioned first-stage curve corresponds to the target required torque. Therefore, the present invention can start from the endpoint of the first-stage curve and then perform the calibration of the first segment of the second-stage curve.

[0182] Optionally, during the calibration process in the initial segment of the second-stage curve, the motor torque needs to be gradually reduced until it reaches the torque required to terminate at the gear teeth. Therefore, this invention can use one or more different reduction step sizes during the process of gradually reducing the motor torque, and this invention does not impose any limitations on this.

[0183] Optionally, in some alternative implementations, step S3000 includes: steps 9.1, 9.2, 9.3, and 9.4;

[0184] Step 9.1: Stop supplying power to the motor for the second time;

[0185] Step 9.2: Using the fifth torque value as the decreasing step size, control the motor torque to continuously decrease from the target required torque for a fourth time period according to a preset cycle;

[0186] Optionally, taking a preset period of 0.1 milliseconds and a fourth time length of 10 milliseconds as an example, during the fourth time length, the present invention reduces the motor torque every 0.1 milliseconds, each time reducing the fifth torque value; the present invention does not impose any limitations on this.

[0187] Step 9.3: After the torque of the motor continues to decrease for the fourth time length, the torque of the motor continues to decrease for the fifth time length according to the preset cycle, with the sixth torque value as the reduction step size, wherein the sixth torque value is less than the fifth torque value;

[0188] Optionally, for step 9.3, please refer to the foregoing explanation for analogy; the present invention will not elaborate further on this.

[0189] Step 9.4: After the torque of the motor continues to decrease for the fifth time length, the torque of the motor continues to decrease for the sixth time length according to the preset cycle, with the seventh torque value as the reduction step. This continues until the torque of the motor decreases to the tooth termination torque, thereby completing the calibration of the first segment of the second stage curve. The seventh torque value is less than the sixth torque value.

[0190] Optionally, before the motor torque is reduced to the tooth termination torque, the present invention may use any number of different reduction steps to gradually reduce the motor torque, and the present invention does not limit this.

[0191] It should be noted that before the motor torque decreases to the tooth termination torque, the reduction step sizes used in this invention exhibit an overall decreasing trend. Of course, the reduction step sizes do not necessarily have to be sequentially decreasing. For example, the reduction step sizes can be in a relationship of both increasing and decreasing. For instance, several consecutive reduction step sizes may be sequentially decreasing, followed by at least one subsequent reduction step size that is sequentially increasing. That is, each reduction step size can be larger or smaller than the previous one; this invention does not impose any restrictions on this.

[0192] Optionally, the final torque output results in a smoother curve for the motor's torque reduction, with almost no vibration in the vehicle during torque reduction. This requires balancing the conflict between the vehicle's calibrated energy recovery time and gear noise during throttle release, bringing both to a relatively acceptable level. Ultimately, this achieves a relatively acceptable level of gear noise, power, and energy recovery performance, thus satisfying overall vehicle performance requirements.

[0193] S4000: Control the motor to gradually reduce the torque of the motor to zero torque by decreasing the step size with a preset torque value, starting from the torque of the tooth stop. This completes the calibration of the latter part of the second stage curve.

[0194] Optionally, the preset torque value mentioned in this invention can be set according to the actual vehicle calibration requirements, and this invention does not impose any restrictions on it.

[0195] Optionally, the first segment of the second-stage curve and the second segment of the second-stage curve can be spliced ​​together to form a complete second-stage curve.

[0196] S5000: Starting from the point where the torque of the motor decreases to zero, the torque of the motor is gradually reduced to negative torque by decreasing the step size by at least one torque value, thereby completing the calibration of the third stage curve.

[0197] Optionally, after the second power supply is stopped, the motor torque decreases to zero according to the calibration curve, and the vehicle enters the energy recovery phase. Thereafter, the present invention also employs a segmented torque step method, causing the motor to execute negative torque. The difference from positive torque increases or decreases is that it does not require calibration of the starting or ending torque at the tooth contact point; instead, the motor is controlled by gradually increasing torque steps, aiming to ensure smooth torque execution by the motor and eliminate vehicle vibration.

[0198] For example, in some alternative implementations, S5000 includes: step 10.1;

[0199] Step 10.1: Starting from the point where the motor torque is reduced to zero, control the motor torque to gradually decrease to the negative torque by reducing the step size by at least one torque value, thereby completing the calibration of the third stage curve;

[0200] During the process of gradually decreasing the step size, the motor torque gradually decreases to the negative torque, during which the motor gears mesh.

[0201] Optionally, as the motor torque gradually decreases to negative torque, the motor's driving teeth can move backward to engage with the driven teeth.

[0202] Optionally, in some alternative implementations, step 10.1 includes: steps 11.1, 11.2, and 11.3;

[0203] Step 11.1: Starting from the point where the motor torque is reduced to zero, the torque of the motor is controlled to decrease continuously for a seventh time period according to the eighth torque value and a preset cycle.

[0204] Step 11.2: After the torque of the motor continues to decrease for the seventh time length, the torque of the motor continues to decrease for the eighth time length according to the preset cycle, with the ninth torque value as the reduction step size, wherein the ninth torque value is greater than the eighth torque value.

[0205] Step 11.3: After the torque of the motor continues to decrease for the eighth time length, the torque of the motor continues to decrease for the ninth time length according to the preset cycle, with the tenth torque value as the reduction step. This continues until the torque of the motor is reduced to the preset negative torque, thereby completing the calibration of the third stage curve. The tenth torque value is greater than the ninth torque value.

[0206] Optionally, the present invention does not impose specific limitations on the magnitude of the preset negative torque, which can be set according to actual needs.

[0207] S6000: Supply power to the motor for the third time, and control the motor to gradually increase the torque of the motor to the zero torque by increasing the step size by at least one torque value, starting from the negative torque, thereby completing the calibration of the fourth stage curve;

[0208] After pressing the accelerator again (the third power supply), the torque executed by the motor changes from negative to positive. During the phase where the executed torque changes from negative to zero, a method of gradually decreasing the torque step size is used to approach zero torque, and the torque curve also needs to be smooth. At this point, the torque curve executed by the motor across the entire torque range can be obtained. The smooth curve eliminates vehicle vibration, and gear noise is effectively suppressed.

[0209] For example, in some alternative implementations, S6000 includes: step 12.1;

[0210] Step 12.1: Supply power to the motor for the third time, starting from the negative torque, and gradually increase the torque of the motor to the zero torque by increasing the step size by at least one torque value, thereby completing the calibration of the fourth stage curve;

[0211] The increments decrease sequentially.

[0212] Optionally, in some alternative implementations, step 12.1 includes: steps 13.1, 13.2, 13.3, and 13.4;

[0213] Step 13.1: Provide the motor with power for the third time;

[0214] Step 13.2: Starting from the negative torque, increase the step size by the eleventh torque value, and control the torque of the motor to increase continuously from the negative torque for the tenth time period according to the preset cycle;

[0215] Step 13.3: After the torque of the motor continues to increase for the tenth time length, the step size is increased by the twelfth torque value, and the torque of the motor continues to increase for the eleventh time length according to the preset cycle, wherein the twelfth torque value is less than the eleventh torque value.

[0216] Step 13.4: After the torque of the motor continues to increase for the eleventh time length, the step size is increased by the thirteenth torque value. According to the preset cycle, the torque of the motor is controlled to continue to increase for the twelfth time length, and so on, until the torque of the motor increases to the zero torque, thereby completing the calibration of the fourth stage curve, wherein the thirteenth torque value is less than the twelfth torque value.

[0217] S7000: The torque curve is obtained based on the first stage curve, the second stage curve, the third stage curve, and the fourth stage curve.

[0218] Optionally, in some alternative implementations, S7000 includes: steps 14.1, 14.2, and 14.3;

[0219] Step 14.1: Merge and splice the first stage curve and the second stage curve end to end;

[0220] Step 14.2: Merge and splice the second-stage curve with the third-stage curve.

[0221] Step 14.3: Merge and splice the third-stage curve and the fourth-stage curve to obtain the torque curve.

[0222] In summary, the torque curve calibration process was performed while effectively suppressing gear-related noise, and a balance was struck between acceleration and energy recovery performance. However, it still reduced acceleration performance when accelerating and energy recovery performance when releasing the accelerator. Therefore, this invention can add a speed loop PI controller strategy based on the calibrated torque curve. This closed-loop control strategy suppresses speed fluctuations during the gear-related phase, thus correcting the calibrated torque curve. This further suppresses gear-related noise and reduces the execution time of smaller torque steps, improving overall vehicle acceleration and energy recovery performance.

[0223] S400. Based on the control torque, control the gears of the motor to mesh.

[0224] Optionally, the motor is actually controlled by current. Therefore, the present invention can determine the corresponding current based on the control torque to control the motor's operation.

[0225] For example, in some alternative implementations, S400 includes: steps 15.1 and 15.2;

[0226] Step 15.1 Based on the control torque, consult the corresponding pre-calibrated table to obtain the corresponding motor DQ shaft current;

[0227] Optionally, the motor DQ axis current is a well-known concept in the art, and this invention will not describe it in detail. Please refer to the relevant descriptions in the art for details.

[0228] Optionally, in some alternative implementations, step 15.1 includes: step 16.1;

[0229] Step 16.1: If the control torque is within the preset small torque range, then query the corresponding pre-calibrated first table to obtain the corresponding motor DQ axis current. The lookup torque step size of the first table is N times the normal torque step size. The normal torque step size is equal to M times the maximum peak torque of the motor. Both N and M are greater than 0 and less than 1.

[0230] Optionally, when calibrating the motor DQ axis current on the test bench, the step size used in the calibration process is the aforementioned lookup torque step size. That is, the first table obtained after final calibration uses the lookup torque (two adjacent lookup torques differ by one lookup torque step size) and the corresponding motor DQ axis current as key-value pairs. When the aforementioned control torque is within a preset small torque range, it indicates that the motor is in the gear engagement stage, i.e., in the small torque execution stage. Therefore, this invention can obtain a more accurate motor DQ axis current based on the first table.

[0231] Optionally, the maximum peak torque of the motor is a value that can be known by referring to the instructions. If the first table is constructed using the normal torque step size calculated from this maximum peak torque, the resulting first table will not be accurate enough in terms of query precision, and the query results will naturally also be inaccurate. Therefore, for motors in the gear engagement stage, the corresponding motor DQ shaft current needs to be queried using the first table in step 16.1 to improve the accuracy of the present invention.

[0232] Optionally, in some alternative implementations, step 15.1 includes: step 17.1;

[0233] Step 17.1: If the control torque is outside the preset small torque range, then query the corresponding pre-calibrated second table to obtain the corresponding motor DQ axis current. The lookup torque step size of the second table is the normal torque step size, which is equal to M times the maximum peak torque of the motor, where M is greater than 0 and less than 1.

[0234] Optionally, if the controlled torque is outside the preset low torque range, it indicates that the motor is in the high torque stage, and the accuracy requirement can be appropriately relaxed. Therefore, the present invention can use the second table to look up the corresponding motor DQ axis current.

[0235] Optionally, if the control torque is outside the preset small torque range, it indicates that the current stage is not the gear engagement stage. That is, it is not necessary to achieve the stage from gear disengagement to gear engagement. Therefore, "making the gears of the motor engage" in step 15.1 can be understood as maintaining the gears in an engaged state.

[0236] Step 15.2: Control the operation of the motor based on the DQ axis current of the motor, so that the gears of the motor mesh.

[0237] like Figure 5 As shown, the present invention provides a gear backlash engagement torque control system, including: a motor 100, a speed loop torque node 200, a torque superposition node 300, and a variable PI control current loop 400.

[0238] The motor 100 is connected to the speed loop torque node 200, the speed loop torque node 200 is connected to the torque superposition node 300, and the torque superposition node 300 is connected to the variable PI control current loop 400.

[0239] The speed loop torque node 200 is used to obtain the rotational speed of the motor 100 at the current moment;

[0240] The speed loop torque node 200 is used to input the rotational speed as a given value to the speed loop PI controller and periodically adjust the given value to obtain the corresponding speed loop feedback torque.

[0241] The torque superposition node 300 is used to superimpose the speed loop feedback torque with the corresponding pre-calibrated torque to obtain the control torque, wherein the pre-calibrated torque is the torque value corresponding to the current moment in the torque curve obtained by pre-calibrating the whole vehicle.

[0242] The variable PI control current loop 400 is used to control the gears of the motor 100 to mesh based on the control torque.

[0243] The present invention provides a computer-readable storage medium having a program stored thereon, which, when executed by a processor, implements the gear backlash engagement torque control method described in any of the preceding claims.

[0244] like Figure 6As shown, the present invention provides an electronic device 70, which includes at least one processor 701, at least one memory 702 and a bus 703 connected to the processor 701; wherein the processor 701 and the memory 702 communicate with each other through the bus 703; the processor 701 is used to call program instructions in the memory 702 to execute the gear backlash torque control method described above.

[0245] In this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, without necessarily requiring or implying any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0246] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0247] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined in this invention may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0248] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A method for controlling gear backlash engagement torque, characterized in that, include: Obtain the motor's rotational speed at the current moment; The rotational speed is input as a given value to the speed loop PI controller, and the given value is periodically adjusted to obtain the corresponding speed loop feedback torque. The control torque is obtained by superimposing the speed loop feedback torque with the corresponding pre-calibrated torque, wherein the pre-calibrated torque is the torque value corresponding to the current moment in the torque curve obtained by pre-calibrating the whole vehicle; Based on the control torque, the gears of the motor are controlled to mesh; The vehicle calibration process for the torque curve includes: The motor is powered on for the first time to obtain the minimum torque that makes the motor rotate; A second power supply is supplied to the motor, and the motor is controlled to start from a stationary state and gradually increase the torque of the motor by increasing the step size by at least one torque value until the initial torque of tooth engagement and the target required torque are reached, thereby completing the calibration of the first stage curve. The initial torque of tooth engagement is equal to the minimum torque, and the target required torque is greater than the minimum torque. Stop supplying power to the motor for the second time, and control the motor to gradually reduce the torque of the motor from the target required torque by a decreasing step size of at least one torque value until the tooth-stopping torque is reached, thereby completing the calibration of the first part of the second stage curve, wherein the tooth-stopping torque is equal to the minimum torque; The motor is controlled to gradually reduce its torque to zero starting from the point where the tooth ends, with a preset torque value decreasing in step size, thereby completing the calibration of the latter part of the second stage curve; Starting from the point where the torque of the motor decreases to zero, the torque of the motor is gradually reduced to negative torque by decreasing the step size by at least one torque value, thereby completing the calibration of the third-stage curve; The motor is powered on for the third time, and the motor is controlled to gradually increase its torque to zero torque, starting from the negative torque and increasing the torque step by at least one torque value, thereby completing the calibration of the fourth stage curve. The torque curve is obtained based on the first stage curve, the second stage curve, the third stage curve, and the fourth stage curve.

2. The method according to claim 1, characterized in that, The first power supply to the motor to obtain the minimum torque required to rotate the motor includes: The first power supply is provided to the motor; The minimum torque required to rotate the motor is obtained by reading the vehicle's overall message.

3. The method according to claim 1, characterized in that, The process of supplying power to the motor a second time, controlling the motor to start from a standstill, and gradually increasing the motor torque in increments of at least one torque value until reaching the initial torque at the gear engagement point and the target required torque, thereby completing the calibration of the first-stage curve, includes: The second power supply is provided to the motor; Starting from the stationary state, the motor is controlled to gradually increase its torque to the initial torque of the tooth engagement step by step, starting with a first torque value; The torque of the motor is controlled to gradually increase from the initial torque of the toothed motor to the target required torque by increasing the step size by at least one torque value, thereby completing the calibration of the first stage curve, wherein each of the increasing step sizes increases sequentially.

4. The method according to claim 3, characterized in that, The step of increasing the motor torque by at least one torque value in increments, starting from the initial torque of the toothed section and gradually increasing it to the target required torque, thereby completing the calibration of the first stage curve, includes: The second torque value is used to increase the step size, and the torque of the motor is controlled to increase continuously from the initial torque of the tooth according to a preset cycle for a first time length. After the torque of the motor continues to increase for the first time length, the torque of the motor continues to increase for the second time length according to the preset period by increasing the step size by the third torque value, wherein the third torque value is greater than the second torque value; After the torque of the motor continues to increase for the second time length, the torque is increased by a fourth torque value in increments, and the torque of the motor continues to increase for a third time length according to the preset cycle. This process is repeated until the torque of the motor increases to the target required torque, thereby completing the calibration of the first stage curve. The fourth torque value is greater than the third torque value.

5. The method according to claim 4, characterized in that, The method further includes: During the first time period during which the torque of the motor continues to increase: the gears of the motor engage.

6. The method according to claim 1, characterized in that, The process of stopping the second power supply to the motor, controlling the motor to gradually reduce its torque from the target required torque by at least one torque value in decreasing steps until the gear termination torque is reached, thereby completing the calibration of the first segment of the second-stage curve, includes: Stop supplying power to the motor for the second time; Using the fifth torque value as the decreasing step size, and according to a preset cycle, the torque of the motor is controlled to continuously decrease from the target required torque for a fourth time period. After the torque of the motor continues to decrease for the fourth time length, the torque of the motor continues to decrease for the fifth time length according to the preset period, with a sixth torque value as the reduction step, wherein the sixth torque value is less than the fifth torque value; After the torque of the motor continues to decrease for the fifth time length, the torque of the motor continues to decrease for the sixth time length according to the preset cycle, with the seventh torque value as the reduction step. This continues until the torque of the motor decreases to the tooth-stopping torque, thereby completing the calibration of the first segment of the second stage curve. The seventh torque value is less than the sixth torque value.

7. The method according to claim 1, characterized in that, The control of the motor, starting from reducing to zero torque, gradually reduces the motor torque to negative torque by decreasing the step size by at least one torque value, thereby completing the calibration of the third-stage curve, including: Starting from the point where the motor torque is reduced to zero, the torque of the motor is gradually reduced to the negative torque by at least one torque value as a decreasing step, thereby completing the calibration of the third stage curve. The decreasing steps are increased sequentially. During the period when the torque of the motor is gradually reduced to the negative torque, the gears of the motor engage.

8. The method according to claim 7, characterized in that, Starting from the point where the motor torque is reduced to zero, the torque of the motor is gradually reduced to the negative torque by decreasing the step size by at least one torque value, thereby completing the calibration of the third-stage curve, including: Starting from the point where the motor torque decreases to zero, the torque of the motor is controlled to decrease continuously for a seventh time period, with the eighth torque value as the decreasing step size, according to a preset cycle. After the torque of the motor continues to decrease for the seventh time length, the torque of the motor continues to decrease for the eighth time length according to the preset period, with the ninth torque value as the decrease step. The ninth torque value is greater than the eighth torque value. After the torque of the motor continues to decrease for the eighth time length, the torque of the motor continues to decrease for the ninth time length according to the preset cycle, with the tenth torque value as the reduction step. This process is repeated until the torque of the motor is reduced to a preset negative torque, thereby completing the calibration of the third stage curve. The tenth torque value is greater than the ninth torque value.

9. The method according to claim 1, characterized in that, The third power supply to the motor, controlling the motor to gradually increase its torque from the negative torque stage to the zero torque stage by increments of at least one torque value, thereby completing the calibration of the fourth-stage curve, includes: The motor is supplied with power for the third time. Starting from the negative torque, the torque of the motor is gradually increased to the zero torque by increasing the step size by at least one torque value, thereby completing the calibration of the fourth stage curve. The step sizes decrease sequentially between each other.

10. The method according to claim 9, characterized in that, The third power supply to the motor, starting from the negative torque, gradually increases the motor torque to zero torque by incrementing by at least one torque value, thereby completing the calibration of the fourth-stage curve, includes: The third power supply is then provided to the motor; Starting from the negative torque, the torque of the motor is controlled to increase by a step size of eleventh torque value according to a preset cycle, starting from the negative torque and continuously increasing for tenth time length. After the torque of the motor continues to increase for the tenth time length, the torque of the motor continues to increase for the eleventh time length according to the preset period, with the twelfth torque value being less than the eleventh torque value. After the torque of the motor continues to increase for the eleventh time length, the step size is increased by the thirteenth torque value. According to the preset cycle, the torque of the motor is controlled to continue to increase for the twelfth time length, and so on, until the torque of the motor increases to the zero torque, thereby completing the calibration of the fourth stage curve, wherein the thirteenth torque value is less than the twelfth torque value.

11. The method according to claim 1, characterized in that, The step of obtaining the torque curve based on the first stage curve, the second stage curve, the third stage curve, and the fourth stage curve includes: The first stage curve and the second stage curve are merged and spliced ​​together end to end; The second-stage curve is merged and spliced ​​with the third-stage curve; The third-stage curve and the fourth-stage curve are merged and spliced ​​together to obtain the torque curve.

12. The method according to any one of claims 1-11, characterized in that, Obtaining the motor's rotational speed at the current moment includes: When the torque step size executed by the motor at the current moment is within the preset step size range, the rotational speed of the motor at the current moment is collected, wherein the torque step size is an increasing step size or a decreasing step size.

13. The method according to claim 12, characterized in that, The step of inputting the rotational speed as a given value to the speed loop PI controller and periodically adjusting the given value to obtain the corresponding speed loop feedback torque includes: The rotational speed is input as a given value to the speed loop PI controller; Based on the difference between the speed loop feedback torque output by the speed loop PI controller based on the rotational speed and the preset feedback torque, the adjustment step size for adjusting the input to the given value of the speed loop PI controller is determined; According to the adjustment step size, the input to the given value of the speed loop PI controller is gradually increased until the difference between the speed loop feedback torque output by the speed loop PI controller and the preset feedback torque meets the preset condition.

14. The method according to claim 13, characterized in that, The step of determining the adjustment step size for adjusting the given value input to the speed loop PI controller based on the difference between the speed loop feedback torque output by the speed loop PI controller based on the rotational speed and the preset feedback torque includes: If the difference between the speed loop feedback torque output by the speed loop PI controller based on the rotational speed and the preset feedback torque is greater than a first difference threshold, then the adjustment step size is determined to be the first adjustment step size. If the difference between the speed loop feedback torque output by the speed loop PI controller based on the rotational speed and the preset feedback torque is not greater than the first difference threshold, then the adjustment step size is determined to be the second adjustment step size, wherein the second adjustment step size is smaller than the first adjustment step size.

15. The method according to claim 13, characterized in that, After the difference between the speed loop feedback torque output by the speed loop PI controller and the preset feedback torque meets the preset condition, the method further includes: If the speed loop feedback torque output by the speed loop PI controller is greater than the preset upper limit threshold, then the final obtained speed loop feedback torque is determined to be the preset upper limit threshold. If the speed loop feedback torque output by the speed loop PI controller is less than the preset lower threshold, then the final speed loop feedback torque is determined to be the preset lower threshold. If the speed loop feedback torque output by the speed loop PI controller is not greater than the preset upper limit threshold and not less than the preset lower limit threshold, then the final obtained speed loop feedback torque is determined to be the speed loop feedback torque output by the speed loop PI controller.

16. The method according to claim 15, characterized in that, After determining the final speed loop feedback torque, the method further includes: Calculate the torque difference between the speed loop feedback torque output by the speed loop PI controller and the torque of the final obtained speed loop feedback torque; The torque difference is processed by an anti-saturation function and then multiplied by a preset anti-saturation coefficient. The resulting product is used as the negative feedback of the speed loop PI controller.

17. The method according to claim 16, characterized in that, The step of superimposing the speed loop feedback torque with a corresponding pre-calibrated torque to obtain the control torque includes: The control torque is obtained by adding the speed loop feedback torque to the corresponding pre-calibrated torque.

18. The method according to claim 17, characterized in that, After adding the speed loop feedback torque to the corresponding pre-calibrated torque to obtain the control torque, the method further includes: If the control torque is greater than the preset speed loop exit threshold, then the final speed loop feedback torque is determined to be zero, wherein the speed loop exit threshold is obtained by pre-calibration.

19. The method according to claim 18, characterized in that, The calibration process for the velocity loop exit threshold includes: The speed loop exit threshold is set to K times the peak torque of the motor, where K is greater than 0 and less than 1. When the control torque is equal to the set value, if the vibration amplitude of the motor speed is within the preset amplitude range, then the set value is determined as the speed loop exit threshold. If the vibration amplitude of the motor speed is not within the preset amplitude range, the setting value is increased, and when the control torque is equal to the setting value, it is determined again whether the vibration amplitude of the motor speed is within the preset amplitude range. This process is repeated until the speed loop exit threshold is determined.

20. The method according to any one of claims 1-11, characterized in that, The step of controlling the gears of the motor to mesh based on the control torque includes: Based on the control torque, the corresponding pre-calibrated table is consulted to obtain the corresponding motor DQ axis current; The operation of the motor is controlled based on the DQ axis current of the motor, so that the gears of the motor mesh.

21. The method according to claim 20, characterized in that, The step of querying a pre-calibrated table based on the control torque to obtain the corresponding motor DQ axis current includes: If the control torque is within the preset small torque range, the corresponding pre-calibrated first table is consulted to obtain the corresponding motor DQ axis current. The lookup torque step size of the first table is N times the normal torque step size, which is equal to M times the maximum peak torque of the motor. Both N and M are greater than 0 and less than 1.

22. The method according to claim 20, characterized in that, The step of querying a pre-calibrated table based on the control torque to obtain the corresponding motor DQ axis current includes: If the control torque is outside the preset small torque range, the corresponding pre-calibrated second table is consulted to obtain the corresponding motor DQ axis current. The lookup torque step size of the second table is the normal torque step size, which is equal to M times the maximum peak torque of the motor, where M is greater than 0 and less than 1.

23. A gear backlash engagement torque control system, characterized in that, include: Motor, speed loop torque node, torque superposition node, and variable PI control current loop; The motor is connected to the speed loop torque node, the speed loop torque node is connected to the torque superposition node, and the torque superposition node is connected to the variable PI control current loop; The speed loop torque node is used to obtain the motor speed at the current moment; The speed loop torque node is used to input the rotational speed as a given value to the speed loop PI controller and periodically adjust the given value to obtain the corresponding speed loop feedback torque. The torque superposition node is used to superimpose the speed loop feedback torque with the corresponding pre-calibrated torque to obtain the control torque, wherein the pre-calibrated torque is the torque value corresponding to the current moment in the torque curve obtained by pre-calibrating the whole vehicle. The variable PI control current loop is used to control the gears of the motor to mesh based on the control torque; The vehicle calibration process for the torque curve includes: The motor is powered on for the first time to obtain the minimum torque that makes the motor rotate; A second power supply is supplied to the motor, and the motor is controlled to start from a stationary state and gradually increase the torque of the motor by increasing the step size by at least one torque value until the initial torque of tooth engagement and the target required torque are reached, thereby completing the calibration of the first stage curve. The initial torque of tooth engagement is equal to the minimum torque, and the target required torque is greater than the minimum torque. Stop supplying power to the motor for the second time, and control the motor to gradually reduce the torque of the motor from the target required torque by a decreasing step size of at least one torque value until the tooth-stopping torque is reached, thereby completing the calibration of the first part of the second stage curve, wherein the tooth-stopping torque is equal to the minimum torque; The motor is controlled to gradually reduce its torque to zero starting from the point where the tooth ends, with a preset torque value decreasing in step size, thereby completing the calibration of the latter part of the second stage curve; Starting from the point where the torque of the motor decreases to zero, the torque of the motor is gradually reduced to negative torque by decreasing the step size by at least one torque value, thereby completing the calibration of the third-stage curve; The motor is powered on for the third time, and the motor is controlled to gradually increase its torque to zero torque, starting from the negative torque and increasing the torque step by at least one torque value, thereby completing the calibration of the fourth stage curve. The torque curve is obtained based on the first stage curve, the second stage curve, the third stage curve, and the fourth stage curve.

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