Steering motor control method, vehicle-mounted terminal and vehicle

Abstract

The embodiment of the invention is suitable for the technical field of automobiles, and provides a control method of a steering motor, a vehicle-mounted terminal and a vehicle, the method comprises the following steps: determining a rack stroke corresponding to a steering rack according to vehicle state information and steering wheel state information; the vehicle state information comprises a driving speed; the steering wheel state information comprises a turning angle value; the rack speed corresponding to the steering rack is determined according to the vehicle type information of the vehicle and the rack stroke; and controlling a steering motor to output corresponding power according to the rack speed. According to the method, the vehicle-mounted terminal can control the steering motor to output the corresponding power according to the rack speed corresponding to the rack stroke, so that the method provided by the embodiment of the invention can enable the output power of the steering motor to meet the maximum driving force required by the steering rack under the current rack stroke, and the power utilization rate of the steering motor is further improved.

Description

Technical Field

[0001] The embodiments of the present application belong to the field of automobile technology, and in particular, relate to a control method for a steering motor, a vehicle-mounted terminal, and a vehicle. Background Art

[0002] In recent years, with the development of vehicle electrification and intelligence, the steering gear of the vehicle has also begun to evolve into a wire-controlled steering gear. The wire-controlled steering gear is mainly composed of components such as an electronic control unit, an information acquisition module, a steering motor, and a steering rack. When the driver turns the steering wheel, the information acquisition module will collect the steering wheel angle value and the vehicle's driving speed, and transmit the collected steering angle value and driving speed to the electronic control unit. The electronic control unit can determine the line angle transmission ratio according to the driving speed, and determine the target angle of the wheel according to the line angle transmission ratio and the angle value. Then, the electronic control unit can control the steering motor to drive the steering rack to move according to the preset output power, thereby driving the wheel to turn. Among them, the line angle transmission ratio can be used to represent the relationship between the steering wheel angle and the wheel angle.

[0003] It can be seen that the output power of the steering motor in the prior art is a fixed value, which may cause the driving force output by the steering motor to be greater than the rack force required for the steering rack to move under the current rack stroke, thereby reducing the output power utilization rate of the steering motor. Summary of the invention

[0004] In view of this, embodiments of the present application provide a control method for a steering motor, a vehicle-mounted terminal, and a vehicle, so as to improve the power utilization rate of the steering motor.

[0005] A first aspect of an embodiment of the present application provides a method for controlling a steering motor, comprising:

[0006] Determine the rack travel corresponding to the steering rack according to the vehicle state information and the steering wheel state information; the vehicle state information includes the driving speed; the steering wheel state information includes the steering angle value;

[0007] Determining a rack speed corresponding to the rack stroke according to the vehicle model information; the rack speed is the speed at which the steering rack moves under the action of the rack force required for the rack stroke;

[0008] The steering motor outputs a corresponding power according to the rack speed control.

[0009] In a possible implementation manner of the first aspect, determining a rack speed corresponding to the steering rack according to the vehicle model information and the rack stroke specifically includes:

[0010] Determining a rack force corresponding to the rack stroke according to the vehicle model information and a first relationship; the first relationship includes a corresponding relationship between the rack stroke and the rack force;

[0011] Determine the motor demand value corresponding to the rack force according to the rack force and a second relationship; the second relationship includes a corresponding relationship between the rack force and the motor demand value;

[0012] The rack speed corresponding to the steering rack is determined according to the motor demand value and the first transmission parameter corresponding to the vehicle model information.

[0013] In a possible implementation manner of the first aspect, the motor demand value includes a torque demand value and a speed demand value;

[0014] Determining the motor demand value corresponding to the rack force according to the rack force and the second relationship specifically includes:

[0015] Determining the torque requirement value corresponding to the rack force according to the rack force and a second transmission parameter corresponding to the vehicle model information;

[0016] Determining the speed demand value corresponding to the torque demand value according to the torque-speed relationship curve corresponding to the steering motor;

[0017] The step of determining a rack speed corresponding to the steering rack according to the motor demand value and a first transmission parameter corresponding to the vehicle model information includes:

[0018] The rack speed corresponding to the steering rack is determined according to the rotational speed demand value and the first transmission parameter corresponding to the vehicle type information.

[0019] In a possible implementation manner of the first aspect, the second transmission parameter includes a screw lead, a belt transmission ratio, and a transmission efficiency;

[0020] The step of determining the torque requirement value corresponding to the rack force according to the rack force and the second transmission parameter corresponding to the vehicle model information specifically includes:

[0021] Determine the unit output work corresponding to the rack force according to the rack force and the lead of the screw rod;

[0022] The torque demand value corresponding to the rack force is determined according to the unit output work, the belt transmission ratio and the transmission efficiency.

[0023] In a possible implementation manner of the first aspect, the first transmission parameter includes a screw lead and a belt transmission ratio;

[0024] The step of determining the rack speed corresponding to the steering rack according to the rotation speed requirement value and the first transmission parameter corresponding to the vehicle model information specifically includes:

[0025] Determine the screw speed corresponding to the speed demand value according to the speed demand value and the belt transmission ratio;

[0026] The rack speed corresponding to the steering rack is determined according to the screw rotation speed and the screw lead.

[0027] In a possible implementation manner of the first aspect, determining a rack speed corresponding to the steering rack according to the vehicle model information and the rack stroke includes:

[0028] Determine a speed mapping relationship corresponding to the vehicle according to the vehicle model information;

[0029] According to the rack stroke and the speed mapping relationship, a rack speed corresponding to the rack stroke is determined.

[0030] In a possible implementation manner of the first aspect, determining a rack stroke corresponding to the steering rack according to the vehicle state information and the steering wheel state information includes:

[0031] determining a line angle transmission ratio according to the vehicle state information;

[0032] The rack stroke corresponding to the steering rack is determined according to the line angle transmission ratio and the steering wheel state information.

[0033] In a possible implementation of the first aspect, the vehicle status information also includes at least one of driving acceleration, load value, road friction coefficient, and driving mode; and the steering wheel status information also includes a torque value.

[0034] A second aspect of an embodiment of the present application provides a control device for a steering motor, comprising:

[0035] A travel determination module, used to determine the rack travel corresponding to the steering rack according to vehicle state information and steering wheel state information; the vehicle state information includes the driving speed; the steering wheel state information includes the steering angle value;

[0036] A speed determination module, used to determine a rack speed corresponding to the steering rack according to the vehicle model information and the rack stroke; the rack speed is the speed at which the steering rack moves under the action of the rack force required by the rack stroke;

[0037] The control module is used to control the steering motor to output a corresponding power according to the rack speed.

[0038] A third aspect of an embodiment of the present application provides a vehicle-mounted terminal, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the control method for the steering motor as described in the first aspect above is implemented.

[0039] A fourth aspect of an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the control method of the steering motor as described in the first aspect above is implemented.

[0040] A fifth aspect of the embodiments of the present application provides a computer program product. When the computer program product is run on a computer, the computer executes the control method of the steering motor described in the first aspect.

[0041] A sixth aspect of the embodiments of the present application provides a vehicle, comprising an on-board terminal and a steering motor, wherein the on-board terminal is connected to the steering motor;

[0042] The vehicle-mounted terminal is used to execute the control method of the steering motor as described in the first aspect to control the steering motor to output corresponding power.

[0043] Compared with the prior art, the embodiments of the present application have the following advantages:

[0044] In the embodiment of the present application, the vehicle terminal can determine the rack stroke corresponding to the steering rack according to the vehicle state information and the steering wheel state information; then, the vehicle terminal can determine the rack speed corresponding to the rack stroke according to the vehicle model information corresponding to the vehicle; the vehicle terminal can control the output power of the steering motor according to the rack speed so that the steering rack moves to the rack stroke at the rack speed. It can be seen that through the method provided by this embodiment, the output power of the steering motor is determined by the vehicle terminal according to the rack stroke, that is, the output power of the steering motor can change with the change of the rack stroke of the steering rack. Further, since the rack speed is the speed at which the steering rack moves under the action of the rack force required for the rack stroke, and the rack force required for the steering rack to move under different rack strokes is different. Therefore, by controlling the output power of the steering motor according to the rack speed corresponding to the rack stroke, the output power of the steering motor can meet the power required for the steering rack to continue to move under the current rack stroke, thereby reducing the power consumption of the steering motor and improving the power utilization of the steering motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or prior art descriptions. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0046] Figure 1 is a schematic diagram of a vehicle provided in an embodiment of the present application;

[0047] Figure 2 is a schematic diagram of a control method for a steering motor provided in an embodiment of the present application;

[0048] Figure 3 It is a schematic diagram of a curve showing the relationship between rack travel and speed provided in an embodiment of the present application;

[0049] Figure 4 is a control logic diagram of a wire-controlled steering device provided in an embodiment of the present application;

[0050] Figure 5 is a schematic diagram of another steering motor control method provided in an embodiment of the present application;

[0051] Figure 6 is a schematic diagram of a curve showing the relationship between rack force and rack travel provided in an embodiment of the present application;

[0052] Figure 7 is a schematic diagram of a curve showing the relationship between torque and speed provided in an embodiment of the present application;

[0053] Figure 8 is a schematic diagram of a control device for a steering motor provided in an embodiment of the present application;

[0054] Fig. 9 It is a schematic diagram of a vehicle-mounted terminal provided in an embodiment of the present application. DETAILED DESCRIPTION

[0055] In the following description, specific details such as specific system structures, technologies, etc. are proposed for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from hindering the description of the present application.

[0056] The technical solution of the present application is described below through specific embodiments.

[0057] Reference Figure 1 , shows a schematic diagram of a vehicle provided by an embodiment of the present application. Figure 1 As shown, the wire control steering device 11 of the vehicle 1 may include an information acquisition module 111, a vehicle terminal 112 and a steering motor 113. When the driver turns the steering wheel, the information acquisition module 111 may collect the current vehicle state information of the vehicle and the current steering wheel state information of the steering wheel, and transmit the collected vehicle state information and steering wheel state information to the vehicle terminal 112. Among them, the vehicle state information collected by the information acquisition module 111 may include at least one of the vehicle's driving speed, the vehicle's driving acceleration, the vehicle's load value, the vehicle's current driving mode, and the road friction coefficient of the road where the vehicle is located. The steering wheel state information collected by the information acquisition module 111 may include the steering angle value and / or torque value of the steering wheel. The vehicle terminal 112 can determine the rack stroke of the steering rack according to the vehicle state information and the steering wheel state information, and control the steering motor 113 to output the corresponding power according to the rack speed corresponding to the rack stroke. Among them, the specific method for the vehicle terminal 112 to determine the rack speed according to the vehicle state information and the steering wheel state information, please refer to the content of the method embodiment of this application, which will not be repeated here.

[0058] Reference Figure 2 , shows a schematic diagram of a control method for a steering motor provided by an embodiment of the present application. The method can be applied to a vehicle-mounted terminal. The vehicle-mounted terminal may be an electronic control unit (ECU), a microcontroller unit (MCU), a central processing unit (CPU) and the like. The control method for the steering motor of the vehicle-mounted terminal may specifically include the following steps:

[0059] S201. Determine a rack travel corresponding to a steering rack according to vehicle state information and steering wheel state information.

[0060] In this embodiment, when the vehicle is in the startup state, the information collection module in the wire-controlled steering device can continuously collect the current vehicle status information and steering wheel status information of the vehicle, and send the collected vehicle status information and steering wheel status information to the vehicle terminal. After receiving the vehicle status information and steering wheel status information, the vehicle terminal can determine the rack travel corresponding to the steering rack according to the vehicle status information and the steering wheel status information.

[0061] Among them, the vehicle state information may include the driving speed of the vehicle. In addition to the driving speed, the vehicle state information may also include at least one of the driving acceleration of the vehicle, the load value of the vehicle, the current driving mode of the vehicle, and the road friction coefficient of the road where the vehicle is located. The steering wheel state information may include the steering wheel angle value. In addition to the steering angle value, the steering wheel state information may also include the steering wheel torque value. The rack stroke corresponding to the steering rack may be the distance that the steering rack needs to move to during the current steering operation. The driving mode of the vehicle may be the operating mode of the vehicle pre-set by the R&D personnel during the design stage of the vehicle according to factors such as the power system output, the chassis suspension setting, and the degree of driving automation. Specifically, the driving mode of the vehicle may include but is not limited to the sports mode, the economic mode, the comfort mode, and the like. During the use stage of the vehicle, the user can experience the different performance and automation of the vehicle by selecting different driving modes, thereby obtaining different driving experiences.

[0062] In a possible implementation, after acquiring the vehicle status information, the vehicle-mounted terminal can determine the line angle transmission ratio corresponding to the current state of the vehicle according to the vehicle status information. After determining the line angle transmission ratio, the vehicle-mounted terminal can determine the rack stroke corresponding to the steering wheel status information according to the line angle transmission ratio. It should be noted that the vehicle-mounted terminal can determine the line angle transmission ratio and the rack stroke by any method known to those skilled in the art, and the embodiments of the present application are not intended to specifically limit the method for determining the line angle transmission ratio and the rack stroke.

[0063] In a possible implementation, when the vehicle state information includes any one of the vehicle's driving speed, the vehicle's driving acceleration, the vehicle's load value, the vehicle's current driving mode, and the road friction coefficient of the road on which the vehicle is located, and the steering wheel state information includes the steering angle value and / or the torque value, after the vehicle-mounted terminal obtains the vehicle state information, the vehicle state information and the steering wheel state information can be input into a preset rack travel calculation model to determine the rack travel corresponding to the steering rack through the rack travel calculation model. The rack travel calculation model can be any model known to those skilled in the art, such as a multivariate function model based on an empirical formula, a machine learning algorithm, or a physical dynamics model.

[0064] In a possible implementation, when the vehicle status information acquired by the vehicle terminal is the vehicle's driving speed, and the steering wheel status information is the steering wheel angle value, the vehicle terminal can query the first transmission ratio mapping relationship according to the vehicle's current driving speed to determine the line angle transmission ratio corresponding to the vehicle's current driving speed. Exemplarily, the first transmission ratio mapping relationship can be a first transmission ratio conversion table. Among them, the first transmission ratio conversion table can record a plurality of different speed ranges and the line angle transmission ratios corresponding to each speed range. The vehicle terminal can determine the line angle transmission ratio corresponding to the speed range where the current driving speed is located as the line angle transmission ratio corresponding to the driving speed. After acquiring the line angle transmission ratio, the vehicle terminal can determine the product of the line angle transmission ratio and the steering wheel angle value as the rack stroke corresponding to the steering rack.

[0065] In a possible implementation, when the vehicle status information acquired by the vehicle terminal is the driving mode of the vehicle, and the steering wheel status information is the steering angle value and torque value corresponding to the steering wheel, the vehicle terminal can query the second transmission ratio mapping relationship according to the current driving mode of the vehicle to determine the line angle transmission ratio corresponding to the current driving mode of the vehicle. Exemplarily, the second transmission ratio mapping relationship can be a second transmission ratio conversion table. Among them, the second transmission ratio mapping relationship can include a plurality of different driving modes and the line angle transmission ratios corresponding to each driving mode. After acquiring the line angle transmission ratio, the vehicle terminal can determine the product of the line angle transmission ratio and the steering angle value as the candidate stroke corresponding to the steering rack. The vehicle terminal can query the preset correction coefficient conversion table according to the torque value of the steering wheel to determine the correction coefficient corresponding to the torque value. Then, the vehicle terminal can correct the candidate stroke according to the correction coefficient to determine the rack stroke corresponding to the steering rack.

[0066] S202: Determine a rack speed corresponding to the steering rack according to the vehicle model information and the rack travel.

[0067] In this embodiment, after determining the rack stroke corresponding to the steering rack in the current steering operation, the vehicle-mounted terminal can determine the rack speed corresponding to the steering rack according to the vehicle model information and the rack stroke.

[0068] In a possible implementation, after determining the rack stroke, the vehicle-mounted terminal can input the rack stroke into a speed algorithm pre-set by the R&D personnel to calculate the rack speed corresponding to the rack stroke through the speed algorithm. The specific method for the vehicle-mounted terminal to calculate the rack speed through the speed algorithm is described in the second embodiment of the present application, which will not be described in detail here.

[0069] In a possible implementation, the vehicle terminal may obtain the speed mapping relationship corresponding to the current vehicle according to the vehicle model information. The speed mapping relationship may include rack speeds corresponding to a plurality of different rack strokes. Exemplarily, the speed mapping relationship may be a speed conversion table or a relationship curve between rack stroke and speed. The vehicle terminal may query the speed mapping relationship according to the current rack stroke of the steering rack to determine the rack speed corresponding to the rack stroke from the speed mapping relationship.

[0070] Through the method provided in this embodiment, since the vehicle-mounted terminal can directly query the rack speed corresponding to the rack stroke according to the speed mapping relationship without additional calculation steps, the method provided in this embodiment can improve the response speed of the wire-controlled steering device.

[0071] When the speed mapping relationship is a speed conversion table, after obtaining the rack stroke, the vehicle-mounted terminal can query the speed conversion table according to the rack stroke to determine the rack speed corresponding to the rack stroke. Among them, the speed conversion table can be divided into two types.

[0072] Type 1: The speed conversion table stores multiple different travel ranges and the rack speeds corresponding to each travel range. The vehicle-mounted terminal can use the rack speed corresponding to the travel range in which the rack travel is located as the rack speed corresponding to the rack travel. Among them, the rack speed corresponding to a certain travel range can be calculated by the R&D personnel based on the rack force corresponding to the maximum value in the travel range. The rack speed corresponding to a certain travel range can be calculated by the R&D personnel according to the method described in the second embodiment of the present application. Readers can refer to the method in the second embodiment of the present application, and replace the "rack travel" in the second embodiment with "the maximum value in the travel range" to understand the specific method of setting the speed conversion table by the R&D personnel. See Table 1 below, which is a speed conversion table provided in an embodiment of the present application.

[0073] Table 1

[0074]

[0075] Type 2: The speed conversion table may store all rack strokes of the steering rack and the rack speeds corresponding to each rack stroke. The vehicle-mounted terminal may query the speed conversion table each time the rack stroke is determined to determine the rack speed corresponding to the current rack stroke from the speed conversion table. See Table 2 below for another speed conversion table provided in an embodiment of the present application. Among them, the rack speeds corresponding to each rack stroke in Table 2 can be calculated by the R&D personnel according to the method described in the second embodiment of the present application, which will not be repeated here.

[0076] Table 2

[0077]

[0078]

[0079] When the speed mapping relationship is a curve of the relationship between the rack travel and the speed, after obtaining the rack travel, the vehicle terminal can determine the rack speed corresponding to the rack travel through the curve of the relationship between the rack travel and the speed. Figure 3 , shows a schematic diagram of a relationship curve between rack travel and speed provided in an embodiment of the present application. Figure 3 As shown, the horizontal coordinate of the relationship curve can be the rack travel of the steering rack, the unit can be millimeters, and the range can be 0 mm to 90 mm. The vertical coordinate can be the rack speed of the steering rack, the unit can be millimeters / revolution, and the range can be 0 mm / revolution to 120 mm / revolution.

[0080] On the whole, the rack speed of the steering rack can gradually decrease as the rack stroke increases. When the rack stroke of the steering rack is 0 mm, the rack speed of the steering rack can be 118 mm / rev. When the rack stroke of the steering rack is 10 mm, the rack speed decreases slightly but still remains at a high level. When the rack stroke is between 10 mm and 50 mm, the rack speed begins to decrease slowly. When the rack stroke is greater than 50 mm, the decrease in rack speed begins to increase, especially when the rack stroke is between 60 mm and 90 mm, the rack speed decreases more significantly. When the rack stroke of the steering rack is close to 90 mm, the rack speed of the steering rack can be reduced to 60 mm / rev. Exemplarily, when setting the relationship curve, the R&D personnel can first select multiple rack strokes, and then calculate the rack speeds corresponding to the steering rack at each rack stroke according to the method provided in the second embodiment of the present application. The vehicle-mounted terminal can perform linear fitting according to the rack speeds corresponding to the multiple rack strokes to obtain a relationship curve between the rack stroke and the speed.

[0081] S203, controlling the steering motor to output corresponding power according to the rack speed.

[0082] In this embodiment, after determining the rack speed corresponding to the rack stroke, the vehicle terminal can control the steering motor according to the output power corresponding to the rack speed, so that the steering rack moves to the rack stroke at the rack speed.

[0083] Through the method provided in this embodiment, since the vehicle-mounted terminal can adjust the output power of the steering motor in real time according to the rack stroke of the steering rack, that is, the output power of the steering motor is determined according to the current rack stroke of the steering rack, therefore, the method provided in this embodiment can make the power output of the steering motor closely match the actual steering demand, and thus make the driving force output by the steering motor just meet the rack force required by the current rack stroke, thereby reducing power consumption and improving the power utilization of the steering motor.

[0084] In addition, since the vehicle terminal controls the output power of the steering motor through the rack speed corresponding to the rack travel, and the speed of the steering rack movement is directly related to the speed and accuracy of wheel steering, the accuracy of the wheel steering angle and the accuracy of the wheel steering speed can be improved by controlling the output power of the steering motor according to the rack speed of the steering rack.

[0085] In one possible implementation, the vehicle terminal can continuously collect the actual rack speed of the steering rack through a speed sensor. The vehicle terminal can input the rack speed corresponding to the rack stroke and the actual rack speed into a preset control strategy to determine the output power of the steering motor through the control strategy. Specifically, when the actual rack speed of the steering rack is lower than the rack speed corresponding to the rack stroke, the vehicle terminal can increase the output power of the steering motor; when the actual rack speed of the steering rack is equal to the rack speed corresponding to the rack stroke, the vehicle terminal can maintain the current output power of the steering motor unchanged; when the actual rack speed of the steering rack is greater than the rack speed corresponding to the rack stroke, the vehicle terminal can reduce the output power of the steering motor.

[0086] In a possible implementation, after determining the rack speed of the steering rack, the vehicle terminal can query the preset speed value mapping relationship according to the rack speed to determine the speed output value corresponding to the rack speed. Then, the vehicle terminal can control the speed corresponding to the output of the steering motor according to the speed output value, so that the steering rack moves to the rack stroke at the rack speed.

[0087] See also Figure 4 , shows a control logic diagram of a wire-controlled steering device provided by an embodiment of the present application. Figure 4 As shown. The on-board terminal in the wire-controlled steering gear can detect the vehicle's driving speed in real time through the vehicle speed sensor, and detect the steering wheel's angle value in real time through the angle sensor on the steering wheel. After obtaining the driving speed and the angle value, the on-board terminal can determine the rack stroke corresponding to the steering rack according to the driving speed and the angle value. Then, the on-board terminal can query the speed mapping relationship according to the rack stroke to determine the rack speed of the steering rack. The on-board terminal can control the speed value of the steering motor according to the rack speed so that the steering rack moves to the rack stroke at the rack speed. During the driving process of the vehicle, the on-board terminal can continuously collect the angle value, and continuously control the output power of the steering motor according to the collected angle value, so that the wire-controlled steering gear can respond to the driver's steering operation in time and turn the wheel to the corresponding steering angle.

[0088] Figure 5 The specific implementation flow chart of a control method S202 for a steering motor provided in the second embodiment of the present application is shown. Figure 5 , compared to Figure 2 In the embodiment, the control method of a steering motor provided in this embodiment includes S2021 to S2023, which are described in detail as follows:

[0089] S2021. Determine the rack force corresponding to the rack stroke according to the vehicle model information and the first relationship.

[0090] In this embodiment, after determining the rack stroke corresponding to the steering rack, the vehicle-mounted terminal can obtain the first relationship between the rack force and the rack stroke according to the vehicle model information of the current vehicle. The first relationship may include the corresponding relationship between the rack stroke and the rack force. The first relationship between the rack force and the rack stroke corresponding to a certain vehicle model information can be obtained by the R&D personnel by bench testing the vehicle of the vehicle model information. Among them, the first relationship between the rack force and the rack stroke corresponding to different vehicle model information is different. The first relationship between the rack force and the rack stroke may depend on the front suspension structure of the vehicle. The rack force corresponding to a certain rack stroke may be the maximum driving force required for the steering rack to continue to move under the rack stroke. Specifically, the first relationship between the rack force and the rack stroke may be a relationship curve between the rack force and the rack stroke preset by the R&D personnel, or a rack force conversion table.

[0091] See also Figure 6 , shows a schematic diagram of a curve of the relationship between rack force and rack travel provided by an embodiment of the present application. Figure 6 As shown, the horizontal axis of the relationship curve can be the rack stroke, and its unit can be millimeters; the vertical axis can be the rack force, and its unit can be Newton. The shape of the relationship curve between the rack force and the rack stroke can be a shape approximating a parabola. Specifically, when the rack stroke is between -100 mm and 0 mm, the rack force can gradually decrease as the rack stroke increases. For example, when the rack stroke is about -90 mm, the rack force corresponding to the rack stroke can be 14,000 Newtons, and when the rack stroke is 0 mm, the rack force corresponding to the rack stroke can drop to 7,500 Newtons. When the rack stroke increases from 0 mm to 100 mm, the rack force can gradually increase as the rack stroke increases, and when the rack stroke is about 100 mm, the rack force corresponding to the rack stroke can rise back to 14,000 Newtons.

[0092] S2022. Determine a motor demand value corresponding to the rack force according to the rack force and the second relationship.

[0093] In this embodiment, after determining the rack force corresponding to the rack stroke, the vehicle-mounted terminal can determine the motor demand value corresponding to the current rack force through the second relationship between the rack force and the motor demand value. The motor demand value may include a torque demand value and a speed demand value. The second relationship may include a corresponding relationship between the rack force rack stroke and the motor demand value rack force.

[0094] In one possible implementation, the second relationship between the rack force and the motor demand value can be a demand value conversion table preset by the R&D personnel. After determining the rack force corresponding to the rack stroke, the vehicle-mounted terminal can query the preset demand value conversion table according to the rack force to determine the torque demand value and speed demand value corresponding to the rack force. Among them, the demand value conversion table can store multiple different rack forces, as well as the torque demand values ​​and speed demand values ​​corresponding to each rack force. See Table 3 below, which shows a demand value conversion table provided in an embodiment of the present application.

[0095] Table 3

[0096]

[0097] In a possible implementation, the second relationship between the rack force and the motor demand value may also be a demand value algorithm pre-set by the R&D personnel. After determining the rack force corresponding to the rack stroke, the vehicle terminal may input the rack force into the demand value algorithm to calculate the motor demand value corresponding to the rack force.

[0098] The specific process of the vehicle terminal calculating the motor demand value through the demand value algorithm can be described as follows. Since different vehicles may be equipped with different models of wire-controlled steering gears, after obtaining the rack force corresponding to the rack stroke, the vehicle terminal can obtain the model of the wire-controlled steering gear currently used by the vehicle from the database according to the vehicle model information, and obtain the second transmission parameter corresponding to the current vehicle from the database according to the model of the wire-controlled steering gear.

[0099] Among them, the transmission parameters corresponding to the wire-controlled steering gear can be used to indicate the degree of transmission and the amplification factor of the steering action from the movement of the steering rack to the actual steering of the wheel. The transmission parameters corresponding to the wire-controlled steering gear may depend on the transmission components used by the wire-controlled steering gear. Exemplarily, when the wire-controlled steering gear used by the vehicle is a rack-type electric power steering (Rack-Electronic Power Steering, R-EPS), since the transmission components in the rack-type electric power steering gear mainly include a transmission belt and a ball screw, the transmission parameters corresponding to the rack-type electric power steering gear may include the belt transmission ratio corresponding to the transmission belt, the screw lead corresponding to the ball screw, and the overall transmission efficiency of the wire-controlled steering gear.

[0100] The vehicle terminal can input the rack force and the second transmission parameter into a preset torque function to calculate the torque demand value of the steering motor corresponding to the rack force through the torque function. Specifically, the second transmission parameter may include the lead of the screw, the belt transmission ratio, and the transmission efficiency. Then, the vehicle terminal can obtain the torque and speed relationship curve corresponding to the steering motor, and determine the speed demand value corresponding to the torque demand value based on the torque and speed relationship curve. Figure 7 , shows a torque and speed relationship curve diagram provided by an embodiment of the present application. Figure 7 As shown, the horizontal axis in the figure can represent the speed value of the steering motor, and its unit can be rpm, and the speed range of the steering motor can be from 0 rpm to 4000 rpm. The vertical axis in the figure can represent the torque value of the steering motor, and its unit can be Nm, and the torque range of the steering motor can be from 0 Nm to 7 Nm. As the speed value of the steering motor increases, the torque value of the steering motor can gradually decrease. When the speed value of the steering motor is low, the torque value of the steering motor can be maintained at a high level. When the speed value of the steering motor is greater than 1000 rpm, the torque value of the steering motor can begin to slowly decrease. When the speed value of the steering motor reaches 1500 rpm, the rate of decrease of the torque value accelerates, and then as the speed value continues to increase, the torque value continues to decrease. When the speed value of the steering motor reaches 4000r / min, the torque value can drop to 2 Nm.

[0101] In a possible implementation, the specific process of the vehicle terminal calculating the torque demand value through the torque function can be described as follows. After obtaining the transmission parameters and the rack force, the vehicle terminal can first determine the unit output work corresponding to the current rack force according to the rack force and the lead of the screw in the transmission parameters. Then, the vehicle terminal can determine the torque demand value corresponding to the rack force according to the unit output work, the belt transmission ratio and the transmission efficiency in the transmission parameters. Specifically, the torque function can be as follows:

[0102]

[0103] Among them, T m It can indicate the torque demand value. r It can represent the rack force. n1 can represent the lead of the screw. i1 can represent the belt transmission ratio. η1 can represent the transmission efficiency. F r n1 can represent the unit output work corresponding to the rack force.

[0104] S2023. Determine a rack speed corresponding to the steering rack according to a first transmission parameter corresponding to the motor demand value and the vehicle model information.

[0105] In this embodiment, after determining the motor demand value corresponding to the rack stroke, the vehicle-mounted terminal can determine the transmission parameters corresponding to the current vehicle according to the vehicle model information, and determine the rack speed of the steering rack when the steering rack moves under the push of the rack force according to the motor demand value and the transmission parameters.

[0106] In this embodiment, the rack speed corresponding to the rack stroke is calculated by the vehicle-mounted terminal according to the rack force corresponding to the rack stroke, and the rack force corresponding to the rack stroke is the maximum driving force required for the steering rack to continue to move under the rack stroke. It can be seen that the method provided by this embodiment can make the driving force output by the steering motor to the steering rack just meet the maximum driving force required by the current stroke of the steering rack. Therefore, the method provided by this embodiment can reduce the power consumption of the steering motor, thereby improving the power utilization rate of the steering motor.

[0107] In one possible implementation, after determining the speed demand value corresponding to the rack stroke, the vehicle-mounted terminal can input the speed demand value and the vehicle model information into a preset speed function to calculate the rack speed corresponding to the speed demand value through the speed function. Specifically, the vehicle-mounted terminal can first determine the ball screw speed corresponding to the speed demand value based on the speed demand value and the belt transmission ratio corresponding to the wire-controlled steering gear. Then, the vehicle-mounted terminal can calculate the rack speed based on the screw speed and the screw lead. Among them, the speed function can be specifically as follows:

[0108]

[0109] Among them, V i Can be used to indicate rack speed. V m It can be used to indicate the required speed value. n1 can be used to indicate the lead of the screw. i1 can be used to indicate the belt transmission ratio. It can be used to indicate the screw speed corresponding to the speed demand value.

[0110] Through the method provided in this embodiment, since the vehicle-mounted terminal can calculate the rack speed corresponding to the rack stroke through the transmission parameters corresponding to the vehicle's wire-controlled steering gear, the method provided in this embodiment can make the rack speed calculated by the vehicle-mounted terminal meet the transmission performance of the steering motor. Therefore, the method provided in this embodiment can improve the accuracy of the rack speed, and thus improve the control accuracy when controlling the steering motor according to the rack speed.

[0111] In this application, in order to prove that the wire-controlled steering gear can still achieve the technical effect of reducing the number of steering wheel turns compared to the traditional mechanical steering gear under the control of the method provided in the embodiment of this application. The R&D personnel took the steering wheel speed of 360 degrees / second as an example, and carried out bench testing using the method provided in the embodiment of this application, and recorded the movement time of the steering rack in each travel range, the steering angle of the wheel, and the steering speed of the wheel under the control of the method provided in this embodiment. See Table 4 below, which is a steering information table of a steering rack and wheel provided in the embodiment of this application.

[0112] Table 4

[0113]

[0114] From Table 3 above, it can be seen that the total time required for the steering rack to move from 0 mm to 85 mm can be 0.88 seconds. At this time, since the steering wheel is turned at a speed of 360 degrees / second, when the steering rack moves from -85 mm to 85 mm, the limit steering angle of the steering wheel can be 632 degrees, that is, the number of steering wheel turns can be 1.75. Among them, the limit steering angle of the steering wheel can be the angle value of the steering wheel turning from the limit position at one end to the limit position at the other end. The number of steering wheel turns can be the number of turns required for the steering wheel to turn from the limit position at one end to the limit position at the other end. Among them, the limit position of the steering wheel can correspond to the maximum steering angle of the wheel, so when the steering wheel reaches the limit position, the vehicle wheel will also reach its maximum deflection angle. The traditional mechanical steering gear only supports a line angle transmission ratio of 63 mm / turn. Therefore, when the steering rack moves from -85 mm to 85 mm, the limit steering angle of the steering wheel is 989 degrees, that is, the number of steering wheel turns can be 2.74. It can be seen that, through the control method provided in this embodiment, the wire-controlled steering device can still achieve the effect of reducing the number of steering wheel turns.

[0115] It should be noted that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0116] Reference Figure 8 , shows a schematic diagram of a control device for a steering motor provided in an embodiment of the present application, which may specifically include a travel determination module 801, a speed determination module 802 and a control module 803, wherein:

[0117] The travel determination module 801 is used to determine the rack travel corresponding to the steering rack according to the vehicle state information and the steering wheel state information; the vehicle state information includes the driving speed; the steering wheel state information includes the steering angle value;

[0118] The speed determination module 802 is used to determine the rack speed corresponding to the steering rack according to the vehicle model information and the rack stroke; the rack speed is the speed at which the steering rack moves under the action of the rack force required by the rack stroke;

[0119] The control module 803 is used to control the steering motor to output corresponding power according to the rack speed.

[0120] The speed determination module can also be used to determine the rack force corresponding to the rack stroke according to the vehicle model information and the first relationship; the first relationship includes the corresponding relationship between the rack stroke and the rack force; the motor demand value corresponding to the rack force is determined according to the rack force and the second relationship; the second relationship includes the corresponding relationship between the rack force and the motor demand value; the rack speed corresponding to the steering rack is determined according to the motor demand value and the first transmission parameter corresponding to the vehicle model information.

[0121] The speed determination module can also be used to determine the torque demand value corresponding to the rack force according to the second transmission parameter corresponding to the rack force and the vehicle model information; determine the speed demand value corresponding to the torque demand value according to the torque and speed relationship curve corresponding to the steering motor; and determine the rack speed corresponding to the steering rack according to the speed demand value and the first transmission parameter corresponding to the vehicle model information.

[0122] The speed determination module can also be used to determine the unit output work corresponding to the rack force according to the rack force and the lead of the screw rod; and determine the torque demand value corresponding to the rack force according to the unit output work, the belt transmission ratio and the transmission efficiency.

[0123] The speed determination module can also be used to determine the screw speed corresponding to the speed demand value according to the speed demand value and the belt transmission ratio; and determine the rack speed corresponding to the steering rack according to the screw speed and the screw lead.

[0124] The speed determination module can also be used to determine the speed mapping relationship corresponding to the vehicle according to the vehicle model information; and determine the rack speed corresponding to the rack stroke according to the rack stroke and speed mapping relationship.

[0125] The travel determination module can also be used to determine the line angle transmission ratio according to the vehicle status information; and determine the rack travel corresponding to the steering rack according to the line angle transmission ratio and the steering wheel status information.

[0126] The vehicle status information in the travel determination module also includes at least one of driving acceleration, load value, road friction coefficient, and driving mode; the steering wheel status information also includes torque value.

[0127] As for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method embodiment part.

[0128] Reference Fig. 9 , shows a schematic diagram of a vehicle-mounted terminal provided by an embodiment of the present application. Fig. 9 As shown, the vehicle terminal 900 in the embodiment of the present application includes: a processor 910, a memory 920, and a computer program 921 stored in the memory 920 and executable on the processor 910. When the processor 910 executes the computer program 921, the steps in each embodiment of the above-mentioned steering motor control method are implemented, such as Figure 2 Alternatively, when the processor 910 executes the computer program 921, the functions of each module / unit in the above-mentioned device embodiments are realized, for example Figure 8 Functions of modules 801 to 803 are shown.

[0129] Exemplarily, the computer program 921 may be divided into one or more modules / units, which are stored in the memory 920 and executed by the processor 910 to complete the present application. The one or more modules / units may be a series of computer program instruction segments capable of completing specific functions, which may be used to describe the execution process of the computer program 921 in the vehicle-mounted terminal 900. For example, the computer program 921 may be divided into a travel determination module, a speed determination module, and a control module, and the specific functions of each module are as follows:

[0130] A travel determination module, used to determine the rack travel corresponding to the steering rack according to vehicle state information and steering wheel state information; the vehicle state information includes the driving speed; the steering wheel state information includes the steering angle value;

[0131] A speed determination module, used to determine a rack speed corresponding to the steering rack according to the vehicle model information and the rack stroke; the rack speed is the speed at which the steering rack moves under the action of the rack force required by the rack stroke;

[0132] The control module is used to control the power outputted by the steering motor according to the rack speed.

[0133] The vehicle terminal 900 may include, but is not limited to, a processor 910 and a memory 920. Those skilled in the art will appreciate that Fig. 9 It is only an example of the vehicle-mounted terminal 900 and does not constitute a limitation of the vehicle-mounted terminal 900. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the vehicle-mounted terminal 900 may also include input and output devices, network access devices, buses, etc.

[0134] The processor 910 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0135] The memory 920 may be an internal storage unit of the vehicle-mounted terminal 900, such as a hard disk or memory of the vehicle-mounted terminal 900. The memory 920 may also be an external storage device of the vehicle-mounted terminal 900, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the vehicle-mounted terminal 900. Further, the memory 920 may also include both an internal storage unit of the vehicle-mounted terminal 900 and an external storage device. The memory 920 is used to store the computer program 921 and other programs and data required by the vehicle-mounted terminal 900. The memory 920 may also be used to temporarily store data that has been output or is to be output.

[0136] An embodiment of the present application also discloses a vehicle-mounted terminal, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the control method for the steering motor as described in the aforementioned embodiments is implemented.

[0137] The embodiment of the present application further discloses a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the control method of the steering motor as described in the above-mentioned embodiments is implemented.

[0138] The embodiment of the present application further discloses a computer program product. When the computer program product is run on a computer, the computer is enabled to execute the control method of the steering motor described in the above-mentioned embodiments.

[0139] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application is described in detail with reference to the above-mentioned embodiments, a person skilled in the art should understand that the technical solutions described in the above-mentioned embodiments can still be modified, or some of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A method for controlling a steering motor, characterized in that: include: Determine the rack travel corresponding to the steering rack according to the vehicle state information and the steering wheel state information; the vehicle state information includes the driving speed; the steering wheel state information includes the steering angle value; Determining a rack speed corresponding to the steering rack according to the vehicle model information and the rack stroke; the rack speed is the speed at which the steering rack moves under the action of the rack force required by the rack stroke; The steering motor outputs a corresponding power according to the rack speed control.

2. The method according to claim 1, characterized in that Determining the rack speed corresponding to the steering rack according to the vehicle model information and the rack stroke specifically includes: Determining a rack force corresponding to the rack stroke according to the vehicle model information and a first relationship; the first relationship includes a corresponding relationship between the rack stroke and the rack force; Determine the motor demand value corresponding to the rack force according to the rack force and a second relationship; the second relationship includes a corresponding relationship between the rack force and the motor demand value; The rack speed corresponding to the steering rack is determined according to the motor demand value and the first transmission parameter corresponding to the vehicle model information.

3. The method according to claim 2, characterized in that The motor demand value includes a torque demand value and a speed demand value; Determining the motor demand value corresponding to the rack force according to the rack force and the second relationship specifically includes: Determining the torque requirement value corresponding to the rack force according to the rack force and a second transmission parameter corresponding to the vehicle model information; Determining the speed demand value corresponding to the torque demand value according to the torque-speed relationship curve corresponding to the steering motor; The step of determining a rack speed corresponding to the steering rack according to the motor demand value and a first transmission parameter corresponding to the vehicle model information includes: The rack speed corresponding to the steering rack is determined according to the rotational speed demand value and the first transmission parameter corresponding to the vehicle type information.

4. The method according to claim 3, characterized in that The second transmission parameters include screw lead, belt transmission ratio and transmission efficiency; The step of determining the torque requirement value corresponding to the rack force according to the rack force and the second transmission parameter corresponding to the vehicle model information specifically includes: Determine the unit output work corresponding to the rack force according to the rack force and the lead of the screw rod; The torque demand value corresponding to the rack force is determined according to the unit output work, the belt transmission ratio and the transmission efficiency.

5. The method according to claim 3, characterized in that: The first transmission parameters include screw lead and belt transmission ratio; The step of determining the rack speed corresponding to the steering rack according to the motor demand value and the first transmission parameter corresponding to the vehicle model information specifically includes: Determine the screw speed corresponding to the speed demand value according to the speed demand value and the belt transmission ratio; The rack speed corresponding to the steering rack is determined according to the screw rotation speed and the screw lead.

6. The method according to claim 1, characterized in that The step of determining a rack speed corresponding to the steering rack according to the vehicle model information and the rack stroke includes: Determine a speed mapping relationship corresponding to the vehicle according to the vehicle model information; According to the rack stroke and the speed mapping relationship, a rack speed corresponding to the rack stroke is determined.

7. The method according to any one of claims 1 to 6, characterized in that Determining the rack travel corresponding to the steering rack according to the vehicle state information and the steering wheel state information includes: determining a line angle transmission ratio according to the vehicle state information; The rack stroke corresponding to the steering rack is determined according to the line angle transmission ratio and the steering wheel state information.

8. The method according to claim 6, characterized in that The vehicle status information also includes at least one of driving acceleration, load value, road friction coefficient, and driving mode; the steering wheel status information also includes torque value.

9. A vehicle-mounted terminal, characterized in that: It includes a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the vehicle-mounted terminal implements the control method for the steering motor as described in any one of claims 1-8.

10. A vehicle, characterized in that: It includes a vehicle-mounted terminal and a steering motor, wherein the vehicle-mounted terminal is connected to the steering motor; The vehicle-mounted terminal is used to execute the control method of the steering motor as described in any one of claims 1 to 8 to control the steering motor to output corresponding power.

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