Method and device for controlling working state of wheel-side driving motor

Abstract

The invention relates to the field of vehicle driving motor control, and particularly discloses a wheel side driving motor working state control method and device, and the method comprises the steps: obtaining the instantaneous whole vehicle demand torque according to the real-time accelerator pedal opening degree and the real-time vehicle speed; according to the road gradient and the real-time vehicle speed, the whole vehicle demand torque is predicted; the minimum value of the instantaneous whole vehicle demand torque and the predicted whole vehicle demand torque is taken as the actual whole vehicle demand torque; and controlling the working state of the driving motor according to the actual vehicle demand torque. According to the method, unreasonable driving of a driver is restrained, the actual whole vehicle demand torque is determined by calculating and predicting the whole vehicle demand torque and combining the instantaneous whole vehicle demand torque, power demands of the vehicle under different road conditions and loads are matched, insufficient or excessive power is avoided, the vehicle runs more smoothly, the safety of vehicle driving is improved, and the driving safety of the vehicle is improved. Overload of vehicle mechanical parts is avoided, the service life of the vehicle mechanical parts is prolonged, the working state of the driving motor is reasonably controlled, and energy consumption and vehicle operation cost are reduced.

Description

Technical Field

[0001] The present invention relates to the field of vehicle drive motor control, and particularly to a method and device for controlling the working state of a wheel-side drive motor. Background Art

[0002] The road environment in mining areas is harsh, with frequent and large changes in slope. Vehicles often need to climb steep slopes under heavy loads or descend rapidly when unloaded. At the same time, the road is full of potholes and muddy sections, resulting in continuous changes in vehicle driving resistance. In addition, the load conditions of mining operation vehicles are also very complex. From fully loaded with ore to returning empty, the vehicle mass varies greatly, which further increases the complexity of power requirements.

[0003] The drive control method of traditional mining vehicles is relatively simple. Usually, the power output is determined only based on the driver's operation of the accelerator pedal. However, when the driver operates the accelerator pedal, they may overstep it, resulting in the instantaneous vehicle demand torque far exceeding the actual demand. In this case, if the power is directly output according to this torque, the vehicle is prone to safety problems under complex road conditions. For example, on a slippery road surface, excessive torque will cause the wheels to slip, and in severe cases, the vehicle will lose control; on a steep slope section, too high power output may also cause the vehicle's mechanical components to be overloaded, accelerating wear and even damage. Summary of the Invention

[0004] To solve the above problems, the present invention provides a method and device for controlling the working state of a wheel-side drive motor, which improves vehicle safety, protects vehicle components, and reduces vehicle operation costs.

[0005] In a first aspect, the technical solution of the present invention provides a method for controlling the working state of a wheel-side drive motor, including the following steps: Obtain the instantaneous vehicle demand torque according to the real-time accelerator pedal opening and real-time vehicle speed; Predict the vehicle demand torque according to the road slope and real-time vehicle speed; Take the minimum value of the instantaneous vehicle demand torque and the predicted vehicle demand torque as the actual vehicle demand torque; Control the working state of the drive motor according to the actual vehicle demand torque.

[0006] In an optional embodiment, predicting the vehicle demand torque according to the road slope and real-time vehicle speed specifically includes: Obtain the accelerator pedal opening and vehicle speed at the end of the vehicle startup stage, and obtain the instantaneous vehicle demand torque at this moment according to the accelerator pedal opening and vehicle speed, and mark it as the first effective instantaneous vehicle demand torque; Periodically collect the accelerator pedal opening and vehicle speed after the vehicle startup stage, and calculate the instantaneous vehicle demand torque at the corresponding collection moment according to the accelerator pedal opening and vehicle speed at each collection moment; Detect whether the change in the throttle pedal opening at the current acquisition moment relative to the throttle pedal opening corresponding to the previous effective instantaneous vehicle demand torque meets the change requirements. If so, mark the instantaneous vehicle demand torque at the current acquisition moment as the effective instantaneous vehicle demand torque; otherwise, mark the instantaneous vehicle demand torque at the current acquisition moment as the invalid instantaneous vehicle demand torque; Take the average value of several effective instantaneous vehicle demand torques before the current acquisition moment as the corrected instantaneous vehicle demand torque; Predict the vehicle demand torque based on the corrected instantaneous vehicle demand torque, the vehicle speed at the previous acquisition moment, and the vehicle speed at the current acquisition moment.

[0007] In an optional embodiment, the predicting the vehicle demand torque based on the corrected instantaneous vehicle demand torque, the vehicle speed at the previous acquisition moment, and the vehicle speed at the current acquisition moment includes: Calculate based on the corrected instantaneous vehicle demand torque and the vehicle speed at the previous acquisition moment through a pre-constructed torque-slope correlation mathematical model to obtain the corrected road slope; Calculate based on the corrected road slope and the vehicle speed at the current acquisition moment through the torque-slope correlation mathematical model to obtain the predicted vehicle demand torque, where the torque-slope correlation mathematical model is constructed based on the relationship between the vehicle demand torque, the road slope, and the vehicle speed.

[0008] In an optional embodiment, the expression of the torque-slope correlation mathematical model is:

[0009] where, is the vehicle demand torque at time , is the vehicle mass, is the gravitational acceleration, is the road slope at time is the rolling resistance coefficient, is the air resistance coefficient, is the vehicle frontal area, is the wheel speed at time is the wheel radius.

[0010] In an optional embodiment, the method further includes the step of calculating the vehicle mass during the vehicle startup phase specifically including: Regarding the instantaneous vehicle demand torque and the vehicle speed corresponding to each acquisition moment as a data item; Based on the data items at any three consecutive acquisition moments, calculate the corresponding vehicle mass calculation value according to the second-order difference of the acceleration; Perform a weighted average on all the vehicle mass calculation values to obtain the final vehicle mass .

[0011] In an optional implementation manner, for the data items at any three consecutive acquisition moments, calculate the corresponding vehicle mass calculation value according to the second-order difference of the acceleration, and specifically calculate through the following formula:

[0012] wherein, is the vehicle speed at the th acquisition moment, is the acquisition time interval, is the instantaneous total vehicle demand torque at the th acquisition moment, is the th vehicle mass calculation value, is the vehicle radius.

[0013] In an optional implementation manner, when detecting whether the change in the currently acquired accelerator pedal opening relative to the accelerator pedal opening corresponding to the previous effective instantaneous total vehicle demand torque meets the change requirement, the change requirement means that the change in the accelerator pedal opening does not exceed the first preset threshold and the currently acquired accelerator pedal opening is greater than the second preset threshold.

[0014] In an optional implementation manner, controlling the operating state of the drive motor according to the actual total vehicle demand torque specifically includes: Based on the motor efficiency MAP diagram of the drive motor, calculate the total electric power of the motor system corresponding to the actual total vehicle demand torque for each drive motor intervention quantity mode respectively; Sort the total electric power of the motor system corresponding to the actual total vehicle demand torque for each drive motor intervention quantity mode; Take the drive motor intervention quantity mode corresponding to the minimum total electric power of the motor system as the target drive motor intervention quantity mode, and control the intervention modes of each drive motor according to the target drive motor intervention quantity mode.

[0015] In an optional implementation manner, for calculating the total electric power of the motor system corresponding to the actual total vehicle demand torque for each drive motor intervention quantity mode based on the motor efficiency MAP diagram of the drive motor, it includes: Record the number of drive motors intervened in the current drive motor intervention quantity mode as ; Detect whether the actual total vehicle demand torque meets , where is the maximum allowable output torque of the drive motor; If not, detect the next drive motor intervention quantity mode until a drive motor intervention quantity mode that meets is found; According to the number of drive motors intervening in the current drive motor intervention quantity mode, divide the actual vehicle demand torque equally to obtain the output torque of each drive motor; According to the motor efficiency MAP of the drive motor, obtain the efficiency corresponding to the output torque of the drive motor; Calculate the electric power of the drive motor according to the rotational speed, output torque, and efficiency of the drive motor; Sum the electric powers of all drive motors to obtain the total electric power of the motor system corresponding to the actual vehicle demand torque.

[0016] In a second aspect, the technical solution of the present invention provides a wheel-side drive motor working state control device, including: An instantaneous vehicle demand torque acquisition module for acquiring the instantaneous vehicle demand torque according to the real-time throttle pedal opening and the real-time vehicle speed; A predicted vehicle demand torque acquisition module for predicting the vehicle demand torque according to the road gradient and the real-time vehicle speed; An actual vehicle demand torque acquisition module for taking the minimum value of the instantaneous vehicle demand torque and the predicted vehicle demand torque as the actual vehicle demand torque; A motor working state control module for controlling the working state of the drive motor according to the actual vehicle demand torque.

[0017] It can be seen from the above technical solutions that the present application has the following advantages: First, acquire the instantaneous vehicle demand torque according to the real-time throttle pedal opening and the real-time vehicle speed. Second, calculate the predicted vehicle demand torque according to the road gradient and the real-time vehicle speed. Then, take the minimum value of the instantaneous vehicle demand torque and the predicted vehicle demand torque as the actual vehicle demand torque. Finally, control the working state of the drive motor according to the actual vehicle demand torque. The present invention restricts the unreasonable driving of the driver. By calculating the predicted vehicle demand torque and combining the instantaneous vehicle demand torque to determine the actual vehicle demand torque, it can better match the power requirements of the vehicle under different road conditions (such as climbing, descending, passing through pothole sections, etc.) and loads (fully loaded, unloaded), avoid power shortage or excess, make the vehicle run more smoothly, improve the driving safety of the vehicle, avoid overloading of vehicle mechanical components, improve the service life of vehicle mechanical components, and then reasonably control the working state of the drive motor, reduce energy consumption and vehicle operation costs. Description of the Drawings

[0018] To more clearly illustrate the technical solutions of this application, the accompanying drawings required in the description will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0019] Figure 1 Schematic flowchart of a method for controlling the operating state of a wheel-side drive motor provided by an embodiment of the present invention.

[0020] Figure 2 Schematic flowchart of the calculation process of the total electric power of the motor system.

[0021] Figure 3 Schematic block diagram of a device for controlling the operating state of a wheel-side drive motor provided by an embodiment of the present invention. Detailed implementation manners

[0022] To make the application purpose, features, and advantages of this application more obvious and understandable, the technical solutions protected by this application will be clearly and completely described below by using specific embodiments and the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this application, rather than all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by this application.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this invention belongs. The terms used in the description of this invention herein are only for the purpose of describing specific embodiments and are not intended to limit this invention.

[0024] Figure 1 Schematic flowchart of a method for controlling the operating state of a wheel-side drive motor provided by an embodiment of the present invention. Among them, Figure 1 The execution subject can be a device for controlling the operating state of a wheel-side drive motor. The method for controlling the operating state of a wheel-side drive motor provided by an embodiment of the present invention is executed by a computer device. Correspondingly, the device for controlling the operating state of a wheel-side drive motor runs in the computer device. According to different requirements, the order of the steps in this flowchart can be changed, and some can be omitted.

[0025] As Figure 1 shown, the method includes the following steps.

[0026] S1. Obtain the instantaneous vehicle demand torque according to the real-time throttle pedal opening and the real-time vehicle speed.

[0027] In this step, the opening signal of the accelerator pedal is collected in real time by a sensor, and the instantaneous torque demand of the driver is directly calculated by combining the pre-stored mapping relationship of "accelerator pedal opening - vehicle speed - required torque".

[0028] S2. Predict the required torque of the whole vehicle according to the road gradient and the real-time vehicle speed.

[0029] In this step, the predicted required torque of the whole vehicle based on the actual working conditions is calculated according to the road gradient and the real-time vehicle speed, objectively reflecting the road conditions demand and avoiding errors caused by relying on subjective operations.

[0030] S3. Take the minimum value of the instantaneous required torque of the whole vehicle and the predicted required torque of the whole vehicle as the actual required torque of the whole vehicle.

[0031] In this step, the driver's intention (instantaneous required torque) is compared with the road conditions demand (predicted torque), and the smaller value of the two is selected as the final actual required torque, suppressing the torque redundancy caused by the driver's misoperation, reducing the ineffective energy consumption (such as limiting the output during sudden acceleration on a flat road), preventing the motor from overloading or mechanical component damage (such as limiting the torque output under steep slope conditions), and balancing the power and stability to avoid tire skidding or excessive power (such as taking the minimum value to control the output on a slippery road surface).

[0032] S4. Control the working state of the drive motor according to the actual required torque of the whole vehicle.

[0033] In this step, based on the actual required torque, the working state of the drive motor is dynamically adjusted, which can include the number of motors involved and the load distribution. In some optional embodiments, the load is evenly distributed to the working motors. Combining with the motor efficiency MAP diagram, the total electric power in different motor number modes is calculated, and the intervention mode with the optimal energy efficiency is selected to reduce the overall energy consumption and further reduce the operation cost.

[0034] The method for controlling the working state of the in-wheel motor provided in this embodiment restricts the unreasonable driving of the driver. By calculating the predicted required torque of the whole vehicle and determining the actual required torque of the whole vehicle in combination with the instantaneous required torque of the whole vehicle, it can better match the power demand of the vehicle under different road conditions (such as climbing, descending, passing through pothole sections, etc.) and loads (fully loaded, unloaded), avoid power shortage or excess, make the vehicle run more smoothly, improve the driving safety of the vehicle, avoid overloading of the vehicle mechanical components, extend the service life of the vehicle mechanical components, and further reasonably control the working state of the drive motor, reduce the energy consumption and the operation cost of the vehicle.

[0035] Further, as a refinement and extension of the specific implementation manner of the above embodiment, in order to fully illustrate the specific implementation process in this embodiment, another method for controlling the working state of the in-wheel motor is provided, and this method includes the following steps.

[0036] SS1, obtain the instantaneous vehicle demand torque based on the real-time throttle pedal opening and real-time vehicle speed.

[0037] It should be noted that the mapping relationship of "throttle pedal opening - vehicle speed - demand torque" is pre-stored. During the vehicle operation, the analog or digital signals output by the throttle pedal position sensor (such as potentiometer or Hall sensor) are collected in real time through the vehicle electronic control unit (ECU), and converted into the percentage of throttle pedal opening. The current vehicle speed is obtained through the wheel speed sensor or the vehicle CAN bus, and then the pre-stored "throttle pedal opening - vehicle speed - demand torque" mapping table is queried to obtain the instantaneous vehicle demand torque at this time. In some optional embodiments, if the current throttle opening or vehicle speed does not exactly match the mapping table node, the bilinear interpolation method is used to calculate the instantaneous vehicle demand torque.

[0038] SS2, predict the vehicle demand torque based on the road gradient and real-time vehicle speed.

[0039] In some optional embodiments, the vehicle demand torque prediction based on road conditions is carried out by constructing a mathematical model among the vehicle demand torque, road gradient, and vehicle speed. This mathematical model is denoted as the torque-gradient correlation mathematical model, and its expression is as follows: (1) Where, is the vehicle demand torque at time is the vehicle mass, is the gravitational acceleration, is the road gradient at time is the rolling resistance coefficient, is the aerodynamic drag coefficient, is the vehicle frontal area, is the wheel speed at time is the wheel radius.

[0040] The first term inside the parentheses on the right side of Equation (1) represents the gravitational component of the vehicle on the slope, that is, the slope resistance. The second term represents the rolling resistance. The third term represents the aerodynamic drag. Each term corresponds to the resistance that the vehicle needs to overcome when driving on the slope. The sum of the slope resistance, rolling resistance, and aerodynamic drag is the total vehicle resistance, that is, the total driving force demand. The torque-gradient correlation mathematical model of Equation (1) is constructed according to the relationship of driving force = demand torque / wheel radius.

[0041] Based on the torque-gradient correlation mathematical model of Equation (1), according to the road gradient and vehicle speed The predicted vehicle demand torque based on road conditions can be calculated.

[0042] In some alternative embodiments, the vehicle mass in the torque gradient correlation mathematical model of formula (1) is calculated according to the vehicle state in the vehicle startup phase, which specifically includes the following steps.

[0043] Step 1: Consider both the instantaneous vehicle demand torque and vehicle speed corresponding to each acquisition moment as a data item.

[0044] Specifically, during the vehicle startup phase, the throttle pedal opening and vehicle speed are periodically acquired. After each acquisition, according to the pre-stored mapping relationship of throttle pedal opening, vehicle speed, and vehicle demand torque, the instantaneous vehicle demand torque corresponding to the acquisition moment is obtained, and both the instantaneous vehicle demand torque and vehicle speed at each acquisition moment are considered as a data item.

[0045] In some alternative embodiments, the vehicle startup phase refers to the phase from a vehicle speed of 0 to when the instantaneous vehicle torque reaches a preset torque threshold. When the vehicle is in a stationary state (vehicle speed is 0), at this time the driver steps on the throttle pedal, and the vehicle VCU (Vehicle Control Unit) outputs the vehicle demand torque according to the preset "throttle pedal opening - vehicle speed - demand torque" mapping relationship , after a time period (at this time, the change in throttle pedal opening does not exceed 5%), the vehicle speed reaches , and at the end of the time period .

[0046] During the vehicle startup phase, the throttle pedal opening and vehicle speed are periodically acquired, and then the instantaneous vehicle demand torque corresponding to the acquisition moment is obtained according to the "throttle pedal opening - vehicle speed - demand torque" mapping relationship. In this way, at each acquisition moment a data item combination can be obtained , and all the data item combinations within the vehicle startup phase form a set A.

[0047] Step 2: Based on the data items of any three consecutive acquisition moments, calculate the corresponding vehicle mass calculation value according to the second-order difference of acceleration.

[0048] In some alternative embodiments, based on the data items in set A, a vehicle mass calculation value is calculated according to the second-order difference of acceleration through the data items of any three consecutive acquisition moments.

[0049] According to the relationship between vehicle driving force and vehicle acceleration , where is , and is the vehicle demand torque, is the wheel radius, and the acceleration can be derived .

[0050] Based on the above acceleration calculation formula, the second-order difference expression of the acceleration can be calculated as: (2) where is the instantaneous vehicle demand torque at the th acquisition moment, is the calculated value of the vehicle mass at the th vehicle, is the acceleration at the th acquisition moment.

[0051] Calculate according to the relationship between acceleration and speed, which are respectively: (3) (4) (5) where is the vehicle speed at the th acquisition moment, is the acquisition time interval.

[0052] Substitute formulas (3), (4), and (5) into formula (2) to obtain the calculation formula for the calculated value of the vehicle mass, expressed as: (6) It should be noted that in formula (6), starts from 2, and when , .

[0053] Step 3: Perform weighted averaging on all calculated values of the vehicle mass to obtain the final vehicle mass .

[0054] Finally, perform weighted averaging on all calculated values of the vehicle mass to obtain the final vehicle mass .

[0055] In these alternative embodiments, the mass is dynamically calculated based on real-time data (throttle opening, vehicle speed, torque) during the vehicle startup phase, without the need for pre-calibration or manual input. It automatically adapts to different load conditions (such as an empty mining vehicle or a fully loaded ore vehicle), improving the system's adaptability to different working conditions. Based on Newton's second law and the vehicle dynamics model, the acceleration is calculated using the second-order difference method to reduce the influence of speed signal noise and improve the accuracy of mass estimation. Among them, the second-order difference of multi-point speed and torque data effectively smooths the instantaneous measurement error. Moreover, the second-order difference of acceleration can suppress random errors caused by sensor noise and road surface disturbances (such as bumps), enhancing data stability. Additionally, weighted averaging is performed on multiple mass calculation values (for example, data with smaller variance has a higher weight), further reducing the interference of single-point outliers and ensuring the reliability of the final mass value.

[0056] In some alternative embodiments, the road slope can be obtained by calculating the torque-slope correlation mathematical model based on formula (1) using the total vehicle demand torque, and then the predicted total vehicle demand torque is calculated according to the road slope and the real-time vehicle speed. The specific steps are as follows.

[0057] Step 1: Obtain the throttle pedal opening and vehicle speed at the end of the vehicle startup phase, and obtain the instantaneous total vehicle demand torque at this moment according to the throttle pedal opening and vehicle speed, and mark it as the first effective instantaneous total vehicle demand torque.

[0058] In this step, the instantaneous total vehicle demand torque at the end of the vehicle startup phase is obtained, that is, the total vehicle demand torque at the end of the above time period , at this time the vehicle speed reaches , and then by substituting , into formula (1), the road slope at this time can be obtained . Take the total vehicle demand torque as the initial instantaneous total vehicle demand torque , and the road slope as the initial road slope .

[0059] In some alternative embodiments, the mapping relationship between the throttle pedal opening, vehicle speed, and total vehicle demand torque is pre-stored. After obtaining the throttle pedal opening and vehicle speed, the corresponding instantaneous total vehicle demand torque is obtained according to the pre-stored mapping relationship. That is, at the end of the vehicle startup phase, the throttle pedal opening and vehicle speed at this moment are obtained, and then according to the pre-stored mapping relationship, the instantaneous total vehicle demand torque at this moment is obtained.

[0060] Step 2: Periodically collect the throttle pedal opening and vehicle speed after the vehicle startup phase, and calculate the instantaneous total vehicle demand torque at the corresponding collection moments according to the throttle pedal opening and vehicle speed at each collection moment.

[0061] Similar to the periodic acquisition of the accelerator pedal opening and vehicle speed during the vehicle startup phase, during the continuous operation process after the vehicle startup phase, the accelerator pedal opening and vehicle speed are also periodically acquired. After each acquisition, according to the pre-stored mapping relationship among the accelerator pedal opening, vehicle speed, and the instantaneous vehicle demand torque of the entire vehicle, the instantaneous vehicle demand torque at the corresponding acquisition moment is obtained. Similarly, the instantaneous vehicle demand torque and vehicle speed at each acquisition moment can be used as a data item. For example, through sampling, data item combinations are obtained , , , …, , … Among them, respectively represent the instantaneous vehicle demand torque and vehicle speed at the th sampling moment. The sampling periods during the vehicle startup phase and the continuous operation process can be the same or different.

[0062] Step 3: Detect whether the change in the accelerator pedal opening at the current acquisition moment relative to the accelerator pedal opening corresponding to the previous valid instantaneous vehicle demand torque meets the change requirements. If so, mark the instantaneous vehicle demand torque at the current acquisition moment as the valid instantaneous vehicle demand torque; otherwise, mark the instantaneous vehicle demand torque at the current acquisition moment as the invalid instantaneous vehicle demand torque.

[0063] In some optional embodiments, the change requirements mean that the change in the accelerator pedal opening does not exceed the first preset threshold and the currently acquired accelerator pedal opening is greater than the second preset threshold.

[0064] Exemplarily, for , detect whether the accelerator pedal opening corresponding to meets the change requirements relative to the accelerator pedal opening corresponding to . If it meets the requirements, then is the valid instantaneous vehicle demand torque; otherwise is the invalid instantaneous vehicle demand torque. For , if is the valid instantaneous vehicle demand torque, then detect whether the accelerator pedal opening corresponding to meets the change requirements relative to the accelerator pedal opening corresponding to . If is the invalid instantaneous vehicle demand torque, because is the previous valid vehicle demand torque, then detect whether the accelerator pedal opening corresponding to meets the change requirements relative to the accelerator pedal opening corresponding to .

[0065] Step 4: Take the average of several valid instantaneous vehicle demand torques before the current acquisition moment as the corrected instantaneous vehicle demand torque.

[0066] It should be noted that the appropriate window length can be set as needed. For example, for the nth collection moment , the average value of the 5 effective instantaneous vehicle demand torques before this collection moment is used as the corrected instantaneous vehicle demand torque. It should be noted that if the current sampling times have not reached the window length, the average value of all effective instantaneous vehicle demand torques before the current sampling moment is used as the corrected instantaneous vehicle demand torque.

[0067] Step 5: Predict the vehicle demand torque according to the corrected instantaneous vehicle demand torque, the vehicle speed at the previous collection moment, and the vehicle speed at the current collection moment.

[0068] Step 51: Calculate through the torque-slope correlation mathematical model according to the corrected instantaneous vehicle demand torque and the vehicle speed at the previous collection moment to obtain the corrected road slope.

[0069] For the nth collection moment , substitute the corrected instantaneous vehicle demand torque , the vehicle speed at the previous collection moment into the torque-slope correlation mathematical model of formula (1) to obtain the corrected road slope .

[0070] Step 52: Calculate through the torque-slope correlation mathematical model according to the corrected road slope and the vehicle speed at the current collection moment to obtain the predicted vehicle demand torque.

[0071] For the nth collection moment , substitute the corrected road slope , the vehicle speed at the current collection moment into the torque-slope correlation mathematical model of formula (1) to obtain the predicted vehicle demand torque at the current sampling moment . Then, take the minimum value of the instantaneous vehicle demand torque and the predicted vehicle demand torque as the actual vehicle demand torque at the nth collection moment.

[0072] The following takes as an example for further explanation.

[0073] In the first case, if relative to the change in the throttle pedal opening does not exceed 2%, then according to the corrected torque value, take , and then and Substitute into formula (1) to obtain (equivalent to the corrected gradient), and substitute and into formula (1) to predict . Then, compare the predicted with the instant torque value obtained by grasping , and take the smaller of the two as the final .

[0074] In the second case, if with respect to does not meet the requirement that the throttle pedal opening does not exceed 2%, torque weighting correction cannot be performed. Directly substitute the and at the previous moment into formula (1) to obtain (equivalent to the corrected gradient), and substitute and into formula (1) to predict . Then, compare the predicted with the instant torque value obtained by grasping , and take the smaller of the two as the final .

[0075] In the third case, if with respect to meets the requirement that the throttle pedal opening does not exceed 2%, but is less than the preset opening value. In this case, the calculation method of the second case is still used.

[0076] In these alternative embodiments, calculating the road gradient by formula has the following advantages compared with using a sensor to collect the road gradient: the mining area environment is dusty, humid and has frequent vibrations, and physical sensors are vulnerable to contamination or mechanical damage, while formula calculation is not affected by the physical environment. Zero drift or signal failure of the gradient sensor may cause data distortion, and formula calculation is corrected by a dynamic model to reduce the impact of single-point failures; combined with the dynamically calculated vehicle mass (such as unloaded, fully loaded), the formula can reflect the actual force on the vehicle, while the sensor only measures the static geographical gradient and cannot reflect the impact of load changes. Calculating the gradient by integrating data such as torque, vehicle speed, and acceleration is more in line with the actual power demand of the vehicle (for example, the coupling relationship between increased torque and decreased vehicle speed when climbing a slope).

[0077] For SS3, take the minimum value of the instant total vehicle demand torque and the predicted total vehicle demand torque as the actual total vehicle demand torque.

[0078] By comparing the driver's intention (instantaneous required torque) with the road condition requirement (predicted torque) and preferentially selecting the smaller value between the two, torque redundancy caused by driver's misoperation (such as suddenly stepping on the accelerator) can be avoided. For example, on a flat road surface or under low-load conditions, if the instantaneous required torque is too high, the system will limit the output based on the predicted value to reduce ineffective energy consumption. In the scenarios of climbing slopes or heavy loads, the predicted torque may be higher than the instantaneous demand. Selecting the latter at this time can prevent excessive output and further optimize the energy utilization rate.

[0079] When the predicted torque increases significantly due to complex road conditions (such as steep slopes, muddy roads), if the driver suddenly reduces the throttle opening, taking the minimum value can prevent the motor from overheating or being damaged due to continuous high-load operation. The driver's operation may have short-term drastic changes (such as frequent acceleration and deceleration). Taking the minimum value can suppress torque fluctuations, make the power output smoother, and reduce mechanical shocks and wear of transmission components.

[0080] Furthermore, in the variable operating environment of the mining area, the predicted torque is calculated based on objective parameters such as slope and vehicle speed, making it more adaptable to the environment; while the instantaneous torque reflects the driver's subjective operation. Combining the two and taking the minimum value can take into account both environmental requirements and human control, and improve the reliability of the system under extreme working conditions. For example, when the vehicle is slipping, the predicted torque may increase abnormally due to the vehicle speed. At this time, selecting the smaller instantaneous required torque can prevent excessive power output from causing the tires to spin in place and enhance the vehicle's ability to get out of trouble. Moreover, by limiting the required torque to the necessary minimum value, the average load rate of components such as the motor and gearbox can be reduced, heat accumulation and mechanical fatigue can be decreased, and thus the service life of the equipment can be extended.

[0081] SS4, control the working state of the drive motor according to the actual vehicle demand torque.

[0082] In some alternative embodiments, the control of the working state of the drive motor includes the control of the number of motors involved in driving. The actual vehicle demand torque is evenly distributed to all the motors involved in driving, and the number of motors required to be involved in driving is determined with the goal of minimizing the total electric power of the motor system. The specific steps are as follows.

[0083] Step 1, based on the motor efficiency MAP diagram of the drive motor, calculate the total electric power of the motor system corresponding to the actual vehicle demand torque in each mode of the number of drive motors involved.

[0084] Step 2, sort the total electric power of the motor system corresponding to the actual vehicle demand torque in each mode of the number of drive motors involved.

[0085] Step 3, take the mode of the number of drive motors involved corresponding to the minimum total electric power of the motor system as the target mode of the number of drive motors involved, and control the involvement mode of each drive motor according to the target mode of the number of drive motors involved.

[0086] It should be noted that the number of driving motors involved is determined in advance according to the actual structure of the motor system. For example, if the motor system consists of 4 motors, with 2 motors on each side of the vehicle, then there are two modes of the number of driving motors involved, namely the mode in which 4 driving motors are involved and the mode in which 2 driving motors are involved. In the mode in which 2 driving motors are involved, it can be determined which two motors are involved according to specific requirements. For example, if the motor system consists of 8 motors, with 4 motors on each side of the vehicle and two motors in parallel on each side, then there are four modes of the number of driving motors involved, namely the mode in which 8 driving motors are involved, the mode in which 6 driving motors are involved, the mode in which 4 driving motors are involved, and the mode in which 2 driving motors are involved. When not all are involved, it can be determined which motors are involved according to specific requirements.

[0087] Figure 2 It is a schematic diagram of the calculation process of the total electric power of the motor system, which specifically includes the following steps.

[0088] Step 101, record the number of driving motors involved in the current mode of the number of driving motors involved as .

[0089] Step 102, detect whether the actual vehicle demand torque meets , where is the maximum allowable output torque of the driving motor.

[0090] Constrained by its physical properties (such as material strength, heat dissipation ability, controller limitations, etc.), the motor cannot output torque infinitely. is the maximum torque value that a single motor can provide within the safe or design range. The output torque of each motor must satisfy less than or equal to to prevent overload or damage. The actual vehicle demand torque is evenly distributed to each involved motor. Therefore, the actual vehicle demand torque needs to satisfy .

[0091] Step 103, if not, detect the next mode of the number of driving motors involved until a mode of the number of driving motors involved that meets is found.

[0092] For the mode of the number of driving motors involved that does not meet the conditions in Step 102, it is discarded, and then it is detected whether the next mode of the number of driving motors involved meets the conditions in Step 102. For the mode of the number of driving motors involved that meets the conditions, the next operation is performed.

[0093] Step 104, according to the number of driving motors involved in the current mode of the number of driving motors involved, evenly divide the actual vehicle demand torque to obtain the output torque of each driving motor.

[0094] Assume that when the current driving motor intervention quantity mode intervenes the number of driving motors is , then the output torque of each driving motor is .

[0095] Step 105: Obtain the efficiency corresponding to the output torque of the driving motor according to the motor efficiency MAP diagram of the driving motor.

[0096] The motor efficiency MAP diagram shows the efficiency change of the motor at different rotational speeds and torque working points. The motor rotational speed can be obtained according to the vehicle speed, the motor output torque can be obtained according to Step 104, and thus the motor efficiency can be obtained according to the motor efficiency MAP diagram.

[0097] Step 106: Calculate the electric power of the driving motor according to the rotational speed, output torque, and efficiency of the driving motor.

[0098] The calculation formula for the electric power of the driving motor is as follows: (7) where is the electric power of the driving motor, is the rotational speed of the driving motor, is the output torque of the driving motor, is the efficiency of the driving motor.

[0099] Step 107: Sum up the electric powers of all driving motors to obtain the total electric power of the motor system corresponding to the actual vehicle demand torque.

[0100] Multiply the electric power calculated by the above formula (7) by the number of driving motors to obtain the total electric power of the motor system.

[0101] For each driving motor intervention quantity mode that meets the condition , calculate a total electric power of the motor system. The driving motor intervention quantity mode corresponding to the minimum total electric power of the motor system is the target driving motor intervention quantity mode. If the intervention quantity of the target driving motor intervention quantity mode is 4, then select 4 intervening driving motors according to the pre-configured selection rule, and the output torque of each driving motor is the actual vehicle demand torque / 4.

[0102] In the above text, the embodiments of a method for controlling the working state of a wheel-side driving motor are described in detail. Based on the method for controlling the working state of a wheel-side driving motor described in the above embodiments, the embodiments of the present invention also provide a device for controlling the working state of a wheel-side driving motor corresponding to this method.

[0103] Figure 3The figure is a schematic block diagram of a control device for the operating state of a wheel hub motor provided by an embodiment of the present invention. In this embodiment, the control device 300 for the operating state of the wheel hub motor can be divided into multiple functional modules according to the functions it performs. The module referred to in the present invention means a series of computer program segments that can be executed by at least one processor and can complete fixed functions, and are stored in the memory.

[0104] The instantaneous vehicle demand torque acquisition module 310 is used to acquire the instantaneous vehicle demand torque according to the real-time accelerator pedal opening and the real-time vehicle speed.

[0105] The predicted vehicle demand torque acquisition module 320 is used to predict the vehicle demand torque according to the road gradient and the real-time vehicle speed.

[0106] The actual vehicle demand torque acquisition module 330 is used to take the minimum value of the instantaneous vehicle demand torque and the predicted vehicle demand torque as the actual vehicle demand torque.

[0107] The motor operating state control module 340 is used to control the operating state of the drive motor according to the actual vehicle demand torque.

[0108] The control device for the operating state of the wheel hub motor in this embodiment is used to implement the aforementioned control method for the operating state of the wheel hub motor. Therefore, the specific implementation manners in this device can be seen in the embodiment part of the control method for the operating state of the wheel hub motor in the foregoing text. Therefore, its specific implementation manners can be referred to the descriptions of the corresponding various part embodiments, and will not be elaborated here.

[0109] In addition, since the control device for the operating state of the wheel hub motor in this embodiment is used to implement the aforementioned control method for the operating state of the wheel hub motor, its functions correspond to those of the above method, and will not be repeated here.

[0110] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A control method for the operating state of a wheel-side drive motor, characterized in that Including the following steps: Obtain the instantaneous vehicle demand torque according to the real-time throttle pedal opening and the real-time vehicle speed; Predict the vehicle demand torque according to the road gradient and the real-time vehicle speed; Take the minimum value of the instantaneous vehicle demand torque and the predicted vehicle demand torque as the actual vehicle demand torque; Control the working state of the drive motor according to the actual vehicle demand torque.

2. The method for controlling the operating state of the in-wheel motor according to claim 1, wherein Predict the vehicle demand torque according to the road gradient and the real-time vehicle speed, specifically including: Obtain the throttle pedal opening and the vehicle speed at the end of the vehicle starting stage, and obtain the instantaneous vehicle demand torque at that moment according to the throttle pedal opening and the vehicle speed, and mark it as the first effective instantaneous vehicle demand torque; Periodically collect the throttle pedal opening and the vehicle speed after the vehicle starting stage, and calculate the instantaneous vehicle demand torque corresponding to each collection moment according to the throttle pedal opening and the vehicle speed at each collection moment; Detect whether the change in the throttle pedal opening at the current collection moment relative to the throttle pedal opening corresponding to the previous effective instantaneous vehicle demand torque meets the change requirement. If so, mark the instantaneous vehicle demand torque at the current collection moment as the effective instantaneous vehicle demand torque; otherwise, mark the instantaneous vehicle demand torque at the current collection moment as the ineffective instantaneous vehicle demand torque; Take the average value of several effective instantaneous vehicle demand torques before the current collection moment as the corrected instantaneous vehicle demand torque; Predict the vehicle demand torque according to the corrected instantaneous vehicle demand torque, the vehicle speed at the previous collection moment, and the vehicle speed at the current collection moment.

3. The method for controlling the operating state of the in-wheel motor according to claim 2, wherein The predicting the vehicle demand torque according to the corrected instantaneous vehicle demand torque, the vehicle speed at the previous collection moment, and the vehicle speed at the current collection moment includes: Calculate according to the corrected instantaneous vehicle demand torque and the vehicle speed at the previous collection moment through a pre-constructed torque-gradient correlation mathematical model to obtain the corrected road gradient; Calculate according to the corrected road gradient and the vehicle speed at the current collection moment through the torque-gradient correlation mathematical model to obtain the predicted vehicle demand torque, where the torque-gradient correlation mathematical model is constructed based on the relationship between the vehicle demand torque, the road gradient, and the vehicle speed.

4. The method for controlling the operating state of the in-wheel motor according to claim 3, wherein The expression of the torque-gradient correlation mathematical model is: Among them, is the vehicle demand torque at a certain moment, is the vehicle mass, is the acceleration due to gravity, is the road slope at a certain moment, is the rolling resistance coefficient, is the air resistance coefficient, is the vehicle frontal area, is the wheel speed at a certain moment, is the wheel radius.

5. The method for controlling the operating state of the in-wheel motor according to claim 4, characterized in that The method further includes calculating the vehicle mass during the vehicle startup phase The steps specifically include: Regard the instantaneous vehicle demand torque and the vehicle speed corresponding to each collection moment as a data item; Based on the data items of any three consecutive collection moments, calculate the corresponding vehicle mass calculation value according to the second-order difference of the acceleration; The weighted average of all calculated vehicle masses is obtained to get the final vehicle mass .

6. The method for controlling the operating state of the in-wheel motor according to claim 5, wherein The calculating the corresponding vehicle mass calculation value according to the second-order difference of the acceleration based on the data items of any three consecutive collection moments is specifically calculated by the following formula: Among them, is the vehicle speed at the th acquisition moment, is the acquisition time interval, is the instantaneous total vehicle demand torque at the th acquisition moment, is the th calculated value of vehicle mass, is the vehicle radius.

7. The method for controlling the operating state of the in-wheel motor according to claim 2, wherein When detecting whether the change in the throttle pedal opening collected currently relative to the throttle pedal opening corresponding to the previous effective instantaneous vehicle demand torque meets the change requirement, the change requirement means that the change in the throttle pedal opening does not exceed the first preset threshold and the throttle pedal opening collected currently is greater than the second preset threshold.

8. The method for controlling the operating state of the in-wheel motor according to claim 1, characterized in that Control the working state of the drive motor according to the actual vehicle demand torque, specifically including: Based on the motor efficiency MAP diagram of the drive motor, calculate the total electric power of the motor system corresponding to the actual vehicle demand torque in each drive motor intervention quantity mode respectively; Sort the total electric power of the motor system corresponding to the actual vehicle demand torque in each driving motor intervention quantity mode; Take the driving motor intervention quantity mode corresponding to the minimum total electric power of the motor system as the target driving motor intervention quantity mode, and control the intervention mode of each driving motor according to the target driving motor intervention quantity mode.

9. The method for controlling the operating state of the in-wheel motor according to claim 8, characterized in that, Calculating the total electric power of the motor system corresponding to the actual vehicle demand torque in each driving motor intervention quantity mode based on the motor efficiency MAP of the driving motor, including: Record the number of engaged drive motors in the current engaged drive motor quantity mode as ; Detect the actual vehicle demand torque Whether it meets , where is the maximum allowable output torque of the drive motor; Otherwise, detect the next drive motor intervention quantity mode until a drive motor intervention quantity mode that meets is found; According to the number of engaged drive motors in the current drive motor engagement quantity mode, evenly divide the actual vehicle demand torque to obtain the output torque of each drive motor; Obtain the efficiency corresponding to the output torque of the driving motor according to the motor efficiency MAP of the driving motor; Calculate the electric power of the driving motor according to the rotational speed, output torque and efficiency of the driving motor; Sum the electric powers of all driving motors to obtain the total electric power of the motor system corresponding to the actual vehicle demand torque.

10. A control device for the operating state of a wheel-side drive motor, characterized in that, Including: An instantaneous vehicle demand torque acquisition module, configured to acquire an instantaneous vehicle demand torque according to the real-time throttle pedal opening and the real-time vehicle speed; A predicted vehicle demand torque acquisition module, configured to predict the vehicle demand torque according to the road gradient and the real-time vehicle speed; An actual vehicle demand torque acquisition module, configured to take the minimum value of the instantaneous vehicle demand torque and the predicted vehicle demand torque as the actual vehicle demand torque; A motor working state control module, configured to control the working state of the driving motor according to the actual vehicle demand torque.

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