A Differential Steering Wheel Control Method Based on LQR

Abstract

The present invention provides a differential steering wheel control method based on LQR, which relates to the technical field of differential steering wheel control. The method includes collecting the current angle and current angular velocity of the differential steering wheel, and at the same time receiving the target angle and target rotational speed of the differential steering wheel; calculating the current angle difference based on the current angle and the target angle; inputting the current angle difference and the current angular velocity into the LQR controller, calculating the angular acceleration control quantity and converting it into the motor speed control increment; based on the target rotational speed and the current angle difference, adjusting the overall motor speed control quantity according to the motor speed control increment; obtaining the maximum motor rotational speed parameter, and calculating the motor speed control value based on the target rotational speed and the adjusted overall motor speed control quantity and transmitting it to the driver, so that the speed and rotation angle of the differential steering wheel can be accurately controlled, effectively solving the problems of steering wheel vibration and unstable driver load existing in the existing control methods.

Description

Technical Field

[0001] The present invention relates to the technical field of differential steering wheel control, and in particular to a differential steering wheel control method based on LQR. Background Art

[0002] Differential steering wheels have significant advantages in the application of heavy-duty AGVs (Automated Guided Vehicles). Compared with ordinary steering wheels, they have a greater load-bearing capacity, a lower body height, and less wear on the wheels and the ground during in-situ rotation.

[0003] However, the existing differential steering wheel speed control methods usually adopt the method of superimposing the angle difference with linear parameters. This method cannot fully consider the overall rotation acceleration and deceleration characteristics of the steering wheel. In practical applications, it is easy to cause problems such as steering wheel vibration and unstable driver load, which in turn affect the stability and reliability of equipment operation. For example, in the scenario of heavy-duty material handling, the steering wheel cannot be stably controlled, which may cause the materials in the steering wheel to shake or even fall, seriously affecting production efficiency and safety.

[0004] Therefore, it is necessary to provide a differential steering wheel control method based on LQR to solve the above technical problems. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a differential steering wheel control method based on LQR, which is used to solve the problems in the prior art that the speed and rotation angle of the differential steering wheel cannot be accurately controlled, and there are steering wheel vibration and unstable driver load.

[0006] The differential steering wheel control method based on LQR provided by the present invention includes:

[0007] Collect the current angle and current angular velocity of the differential steering wheel, and at the same time receive the target angle and target speed of the differential steering wheel;

[0008] Calculate the current angle difference based on the current angle and the target angle;

[0009] Input the current angle difference and the current angular velocity into the LQR controller, calculate the angular acceleration control quantity and convert it into the motor speed control increment;

[0010] Based on the target speed and the current angle difference, adjust the overall motor speed control quantity according to the motor speed control increment;

[0011] Obtain the maximum motor speed parameter, and calculate the motor speed control value based on the target speed and the adjusted overall motor speed control quantity and transmit it to the driver.

[0012] Preferably, the current angle and the current angular velocity are collected by an absolute encoder on the wheel set frame of the differential steering wheel.

[0013] Preferably, the calculation process of the angular acceleration control quantity is as follows:

[0014] The expression of the continuous-time linear state space model of the LQR controller is as follows:

[0015] In the formula, represents the change rate of the system state vector at time t; represents the system state vector at time t; represents the control input vector at time t; A represents the state matrix; B represents the input matrix;

[0016] At the time t, the current angle difference and the current angular velocity are used as the system state vector , and the angular acceleration control quantity is used as the control input vector . Setting the control time interval as M, the system state vector at time t + 1, the corresponding calculation formula is as follows:

[0017] After converting the above formula, we get:

[0018] In the formula, represents the angle difference control function regarding the current angle difference and the current angular velocity ; represents the angular velocity control function regarding the current angle difference and the current angular velocity ;

[0019] By solving the Jacobian matrix of the formula , the state matrix , the input matrix are obtained;

[0020] Set the state weight matrix , control weight matrix of the LQR controller, where represents the control parameter;

[0021] Set the final control law of the LQR controller as ; feedback gain matrix , where represents the transpose matrix of the input matrix B, represents the matrix inverse matrix; the intermediate matrix P satisfies the formula , where represents the transpose matrix of the state matrix A; represents the inverse matrix of the control weight matrix R;

[0022] By solving the formula , the intermediate matrix P, the feedback gain matrix K and the control input vector are obtained, and the control input vector is the angular acceleration control amount .

[0023] Preferably, the calculation formula for converting the angular acceleration control amount into the motor speed control increment is as follows:

[0024] In the formula, represents the motor speed control increment; represents the angular acceleration control amount; M represents the control time interval; d represents the turning radius of the differential steering wheel; R represents the radius of the differential steering wheel.

[0025] Preferably, based on the target speed and the current angle difference, adjusting the overall motor speed control amount according to the motor speed control increment specifically includes:

[0026] Judge whether the target speed is 0. If the target speed is not 0, the adjusted overall motor speed control amount , where represents the overall motor speed control amount before adjustment, represents the motor speed control increment; if the target speed is 0, then judge whether the current angle difference is less than 0.2°. If the current angle difference is less than 0.2°, the adjusted overall motor speed control amount ;

[0027] If the current angle difference is greater than or equal to 0.2°, then judge whether the current angle difference is greater than 2°. If the current angle difference is greater than 2°, the adjusted overall motor speed control amount ; if the current angle difference is less than or equal to 2°, the adjusted overall motor speed control amount .

[0028] Preferably, obtaining the maximum motor speed parameter, and calculating the motor speed control value based on the target speed and the adjusted overall motor speed control amount and transmitting it to the driver specifically includes:

[0029] Set the maximum rotational speed parameter of the motor to , and the target rotational speed to . If the overall control quantity of the motor speed after adjustment satisfies , then limit , otherwise do not limit ;

[0030] The differential steering wheel is internally provided with a No. 1 motor and a No. 2 motor, and the corresponding motor speed control values are respectively and ;

[0031] Transmit the motor speed control values and to the No. 1 driver corresponding to the No. 1 motor and the No. 2 driver corresponding to the No. 2 motor respectively.

[0032] A differential steering wheel control method based on LQR further includes controlling the current angle and the current angular velocity through the driver based on the motor speed control value.

[0033] A differential steering wheel control system based on LQR, the control system includes:

[0034] An acquisition and reception module, configured to acquire the current angle and the current angular velocity of the differential steering wheel, and at the same time receive the target angle and the target rotational speed of the differential steering wheel;

[0035] A difference calculation module, configured to calculate the current angle difference based on the current angle and the target angle;

[0036] An LQR controller calculation module, configured to input the current angle difference and the current angular velocity into the LQR controller, calculate the angular acceleration control quantity and convert it into a motor speed control increment;

[0037] A control quantity adjustment module, configured to adjust the overall motor speed control quantity based on the target rotational speed and the current angle difference according to the motor speed control increment;

[0038] A driver control module, configured to obtain the maximum rotational speed parameter of the motor, and calculate the motor speed control value based on the target rotational speed and the adjusted overall motor speed control quantity and transmit it to the driver.

[0039] An electronic device includes a memory and a processor. When the processor runs the computer program stored in the memory, the processor executes the steps of a differential steering wheel control method based on LQR as described in any one of the above.

[0040] A readable storage medium stores a computer program, and when the computer program is executed by a processor, it is used to implement the steps of a differential steering wheel control method based on LQR as described in any one of the above.

[0041] Compared with the related technologies, a differential steering wheel control method based on LQR provided by the present invention has the following beneficial effects:

[0042] The present invention can collect the current angle and current angular velocity of the differential steering wheel, and at the same time receive the target angle and target rotational speed of the differential steering wheel; calculate the current angle difference based on the current angle and the target angle; input the current angle difference and the current angular velocity into an LQR controller, calculate the angular acceleration control quantity and convert it into a motor speed control increment; based on the target rotational speed and the current angle difference, adjust the overall motor speed control quantity according to the motor speed control increment; obtain the maximum motor speed parameter, and calculate the motor speed control value based on the target rotational speed and the adjusted overall motor speed control quantity and transmit it to the driver, so as to accurately control the speed and rotation angle of the differential steering wheel, effectively solving the problems of steering wheel vibration and unstable driver load existing in the existing control methods.

[0043] The present invention can establish a differential steering wheel motion model based on LQR, making the steady-state angle tracking error of the differential steering wheel converge to zero, and thus effectively improving the control accuracy of the speed and rotation angle of the differential steering wheel. For differential steering wheels of different specifications and sizes, the method of the present invention has good adaptability, does not need to rely on experience to adjust control parameters, reduces the development cost and debugging difficulty, and saves development time. The present invention fully considers the overall rotational acceleration and deceleration characteristics of the steering wheel, effectively avoiding the problems of steering wheel vibration and unstable driver load, improving the stability and reliability of equipment operation, and reducing the equipment maintenance frequency. Description of the Drawings

[0044] Figure 1 It is a flowchart of a differential steering wheel control method based on LQR provided by an embodiment of the present invention;

[0045] Figure 2 It is a structural schematic diagram of a differential steering wheel provided by an embodiment of the present invention;

[0046] Figure 3 It is a flowchart of adjusting the overall motor speed control quantity provided by an embodiment of the present invention;

[0047] Figure 4 It is a system block diagram of a differential steering wheel control system based on LQR provided by an embodiment of the present invention;

[0048] Figure 5 It is a hardware structural schematic diagram of an electronic device provided by an embodiment of the present invention. Detailed Embodiments

[0049] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are only a part rather than all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0050] As Figure 1 shown, it is a flowchart of a differential steering wheel control method based on LQR provided by an embodiment of the present invention. Figure 1 The execution subject of the method shown can be a software and / or hardware device. The execution subject of the present application may include but is not limited to at least one of the following: user equipment, network equipment, etc. Among them, the user equipment may include but is not limited to computers, smart phones, personal digital assistants (Personal Digital Assistant, abbreviated as: PDA), and the above-mentioned electronic devices, etc. The network equipment may include but is not limited to a single network server, a server group composed of multiple network servers, or a cloud composed of a large number of computers or network servers based on cloud computing. Among them, cloud computing is a type of distributed computing, which is composed of a group of loosely coupled computers to form a super virtual computer. This embodiment does not make any restrictions. It includes steps S1 to S5, specifically as follows:

[0051] S1, collect the current angle and current angular velocity of the differential steering wheel, and at the same time receive the target angle and target speed of the differential steering wheel;

[0052] In practical applications, the differential steering wheel is a special steering wheel and is widely used in equipment such as heavy-duty AGVs. It can achieve more flexible steering and carry a greater weight.

[0053] First, the current angle and current angular velocity of the differential steering wheel can be collected. The current angle refers to the rotation angle of the differential steering wheel at a certain moment, and the current angular velocity refers to the rotation speed of the differential steering wheel at that moment. Both are obtained through an absolute encoder installed on the wheel group frame of the differential steering wheel.

[0054] At the same time, the target angle and target speed of the differential steering wheel can be received. The target angle refers to the rotation angle that the differential steering wheel finally reaches as preset, and the target speed refers to the rotation speed that the differential steering wheel finally reaches as preset. These two parameters determine the movement target of the differential steering wheel.

[0055] S2, calculate the current angle difference based on the current angle and the target angle;

[0056] It is understandable that the current angle difference refers to the angle difference between the current rotation angle and the target rotation angle of the differential steering wheel. The magnitude and sign of this angle difference provide a basis for the subsequent adjustment of the movement of the differential steering wheel.

[0057] S3. Input the current angle difference and the current angular velocity into the LQR controller, calculate the angular acceleration control quantity, and convert it into the motor speed control increment.

[0058] Furthermore, the current angle difference and the current angular velocity can be input into the LQR controller (linear quadratic regulator). The LQR controller can calculate the optimal control quantity, that is, the angular acceleration control quantity, according to the input current angle difference and current angular velocity. It determines the magnitude and direction of the angular acceleration of the differential steering wheel.

[0059] In addition, since the movement of the differential steering wheel is driven by a motor, it is necessary to combine parameters such as the control time interval, the turning radius of the differential steering wheel, and the radius of the differential steering wheel to convert the angular acceleration control quantity into a speed control signal that the motor can accept, that is, the motor speed control increment.

[0060] S4. Based on the target rotational speed and the current angle difference, adjust the overall motor speed control quantity according to the motor speed control increment.

[0061] Among them, the target rotational speed determines the rotational speed that the differential steering wheel ultimately needs to reach, the current angle difference reflects the difference between the current rotation angle and the target rotation angle, and the motor speed control increment is the speed adjustment quantity calculated based on the LQR controller. Considering these factors, the overall motor speed control quantity can be adjusted to ensure that the differential steering wheel can quickly and accurately adjust the angle while meeting the speed requirements.

[0062] S5. Obtain the maximum motor speed parameter, and calculate the motor speed control value based on the target rotational speed and the adjusted overall motor speed control quantity, and transmit it to the driver.

[0063] In practical applications, the maximum motor speed parameter refers to the maximum speed limit that the motor can reach. If the calculated speed exceeds the maximum motor speed parameter, the motor speed control value needs to be limited so that it does not exceed the bearing range of the motor.

[0064] Then, the calculated motor speed control value can be transmitted to the driver. After receiving the control value, the driver will drive the motor to run, so that the speed and rotation angle of the differential steering wheel can be accurately controlled.

[0065] In the specific implementation process, the current angle and the current angular velocity are collected by an absolute encoder on the wheel group frame of the differential steering wheel.

[0066] As shown Figure 2 in the figure, it is a schematic structural diagram of a differential steering wheel provided by an embodiment of the present invention. The rotary support of the differential steering wheel connects the vehicle body load-bearing part and the wheel set frame. The wheel set can rotate around the rotary support, and the wheel set includes Wheel No. 1 and Wheel No. 2. At the same time, an absolute encoder is installed on the wheel set frame for measuring the rotation angle of the differential steering wheel and collecting its current angle and current angular velocity.

[0067] The calculation process of the angular acceleration control amount is as follows:

[0068] The expression of the continuous-time linear state space model of the LQR controller is as follows:

[0069] In the formula, represents the change rate of the system state vector at time t; represents the system state vector at time t; represents the control input vector at time t; A represents the state matrix; B represents the input matrix;

[0070] At the time t, the current angle difference and the current angular velocity are used as the system state vector , and the angular acceleration control amount is used as the control input vector . Assuming that the control time interval is M, the system state vector at time t + 1, the corresponding calculation formula is as follows:

[0071] After converting the above formula, we get:

[0072] In the formula, represents the angle difference control function with respect to the current angle difference and the current angular velocity ; represents the angular velocity control function with respect to the current angle difference and the current angular velocity ;

[0073] By solving the Jacobian matrix of the formula , the state matrix , the input matrix are obtained;

[0074] Assuming the state weight matrix , the control weight matrix of the LQR controller, where Denote the control parameter;

[0075] Set the final control law of the LQR controller as ; the feedback gain matrix , where denotes the transpose matrix of the input matrix B, denotes the matrix 's inverse matrix; the intermediate matrix P satisfies the formula , where denotes the transpose matrix of the state matrix A; denotes the inverse matrix of the control weight matrix R;

[0076] By solving the formula , obtain the intermediate matrix P, the feedback gain matrix K and the control input vector , and the control input vector is the angular acceleration control quantity .

[0077] Among them, by establishing the continuous-time linear state space model of the LQR controller, the current angle difference and current angular velocity of the differential steering wheel can be used as the system state vector. On this basis, the angular acceleration control quantity is calculated, and then the motion state of the differential steering wheel can be accurately adjusted, so that the steady-state angle tracking error of the steering wheel converges to zero, improving the control accuracy of the speed and rotation angle of the differential steering wheel, avoiding the problems of steering wheel vibration and unstable driver load in the traditional method, and ensuring the stability of equipment operation.

[0078] In addition, this calculation process is based on the motion model of the differential steering wheel and has good adaptability to differential steering wheels of different specifications and sizes. Control parameters, such as the parameters in the state weight matrix and the control weight matrix, can be selected according to the actual engineering effect, solving the problem of relying on empirical patchwork to adjust parameters in the traditional method, reducing the development cost and debugging difficulty, facilitating the rapid deployment and optimization of the control scheme in different application scenarios, and enhancing the versatility and flexibility of the entire control system.

[0079] The calculation formula for converting the angular acceleration control quantity into the motor speed control increment is as follows:

[0080] In the formula, denotes the motor speed control increment; denotes the angular acceleration control quantity; M denotes the control time interval; d denotes the turning radius of the differential steering wheel; R denotes the radius of the differential steering wheel.

[0081] In practical applications, through the above formula, the physical characteristics of the differential steering wheel can be accurately matched with the motion requirements. According to the turning radius of the differential steering wheel, the radius of the steering wheel, and the control time interval, the angular acceleration control amount can be accurately converted into the speed control increment suitable for the motor. This makes the speed adjustment of the motor driving the differential steering wheel more reasonable and accurate, helps to achieve precise control of the speed and rotation angle of the differential steering wheel, avoids unstable operation caused by improper conversion of the control amount, and ensures the smoothness and reliability of the operation of equipment such as heavy-duty AGVs.

[0082] Based on the target speed and the current angle difference, adjusting the overall motor speed control amount according to the motor speed control increment specifically includes:

[0083] Judge whether the target speed is 0. If the target speed is not 0, then the adjusted overall motor speed control amount , where represents the overall motor speed control amount before adjustment, represents the motor speed control increment; if the target speed is 0, then judge whether the current angle difference is less than 0.2°. If the current angle difference is less than 0.2°, then the adjusted overall motor speed control amount ;

[0084] If the current angle difference is greater than or equal to 0.2°, then judge whether the current angle difference is greater than 2°. If the current angle difference is greater than 2°, then the adjusted overall motor speed control amount ; if the current angle difference is less than or equal to 2°, then the adjusted overall motor speed control amount .

[0085] As Figure 3 shown, it is the flowchart of adjusting the overall motor speed control amount provided by the embodiment of the present invention. Among them, based on the target speed and the current angle difference, the overall motor speed control amount can be adjusted according to the motor speed control increment. In practical applications, it can effectively improve the control accuracy and operation stability of the differential steering wheel of the heavy-duty AGV, reduce equipment wear, and improve the logistics handling efficiency and safety.

[0086] Exemplarily, in the logistics handling scenario of a certain heavy-duty AGV, the AGV is equipped with a differential steering wheel, and the method of the present invention is used to accurately control the speed and rotation angle of the differential steering wheel.

[0087] First, when the AGV receives a handling task, its control system can obtain the target speed, the current angle difference, and the motor speed control increment of the differential steering wheel, and then adjust the overall motor speed control amount.

[0088] During a material handling task, the AGV needs to transport a batch of heavy goods from Warehouse A to Production Line B. During the startup phase, the target speed of the differential steering wheel is not 0. For example, initially, the overall control amount of the motor speed before adjustment is 500 revolutions per minute. Through the previous control process, the calculated increment of the motor speed control is 100 revolutions per minute. Then, the overall control amount of the motor speed after adjustment is 600 revolutions per minute. The above adjustment process enables the differential steering wheel to respond quickly, thereby driving the AGV to start at a predetermined speed and move forward towards the target location.

[0089] When the AGV is approaching the target location, the target speed can be adjusted to 0. At this time, it is necessary to judge the current angle difference. If the current angle difference is less than 0.2°, it means that the differential steering wheel is already close to the ideal position. To avoid excessive adjustment causing the steering wheel to shake, the overall control amount of the motor speed after adjustment is directly set to 0. For example, after measurement, the current angle difference is 0.1°. Then, the overall control amount of the motor speed after adjustment is set to 0, the differential steering wheel stops rotating, and the AGV stops steadily at the designated position.

[0090] If the current angle difference is greater than or equal to 0.2°, it is further judged whether it is greater than 2°. If the current angle difference is greater than 2°, it means that the angle deviation is large and the adjustment intensity needs to be increased. For example, the overall control amount of the motor speed before adjustment is 500 revolutions per minute, the increment of the motor speed control is 100 revolutions per minute, and the current angle difference is 3°. Then, the overall control amount of the motor speed after adjustment is 600 revolutions per minute, so that the differential steering wheel can quickly adjust the angle and make the AGV return to the correct running track.

[0091] If the current angle difference is less than or equal to 2°, such as the current angle difference is 1.5°, the overall control amount of the motor speed after adjustment remains the same as that before adjustment. This is because the angle deviation is within the acceptable range and no additional speed adjustment is required, thus ensuring the smooth operation of the AGV and avoiding unnecessary impacts on the equipment caused by frequent adjustments.

[0092] The obtaining of the maximum motor speed parameter and the calculation of the motor speed control value based on the target speed and the overall control amount of the motor speed after adjustment and the transmission to the driver specifically include:

[0093] Set the maximum motor speed parameter as and the target speed as . If the overall control amount of the motor speed after adjustment satisfies , then limit , otherwise do not limit ;

[0094] The differential steering wheel is internally provided with a No. 1 motor and a No. 2 motor, and the corresponding motor speed control values are respectively and ;

[0095] Transmit the motor speed control value and to the No. 1 driver corresponding to the No. 1 motor and the No. 2 driver corresponding to the No. 2 motor respectively.

[0096] A differential steering wheel control method based on LQR further includes controlling the current angle and the current angular velocity through the driver based on the motor speed control value.

[0097] In the above material handling task, the maximum rotational speed parameter of the motor of the differential steering wheel is set to 3000 revolutions per minute, and the target rotational speed of the differential steering wheel is set to 1200 revolutions per minute. If the overall control amount of the adjusted motor speed is 600 revolutions per minute, at this time revolutions per minute, this value is less than 3000 revolutions per minute, that is the corresponding value, therefore, there is no need to limit .

[0098] According to the control principle of the differential steering wheel, the speed control value of the No. 1 motor is revolutions per minute, and the speed control value of the No. 2 motor is revolutions per minute. Then, the speed control value of 1800 revolutions per minute of the No. 1 motor can be transmitted to the No. 1 driver, and the speed control value of 600 revolutions per minute of the No. 2 motor can be transmitted to the No. 2 driver.

[0099] After receiving the speed control value, the No. 1 driver drives the No. 1 motor to operate at a speed of 1800 revolutions per minute. After receiving the speed control value, the No. 2 driver drives the No. 2 motor to operate at a speed of 600 revolutions per minute. During the operation of the motor, based on these speed control values, the driver will continuously control the current angle and angular velocity of the differential steering wheel. For example, if the deviation between the current angle of the differential steering wheel and the target angle is large, the driver will adjust the rotational speed of the motor according to the speed control value so that the differential steering wheel quickly turns to the target angle. If the current angular velocity is too fast or too slow, the driver will also adjust the motor rotational speed accordingly to ensure the smooth and accurate movement of the differential steering wheel.

[0100] Based on the above control method, by obtaining the maximum motor speed parameter and restricting the overall control amount of the adjusted motor speed, it is possible to prevent the motor from overspeeding, avoid damaging the motor due to overload, extend the service life of the motor, and reduce the maintenance cost. Moreover, different motor speed control values can be transmitted to the corresponding drivers respectively, thereby accurately regulating the No. 1 and No. 2 motors to achieve precise steering and speed adjustment of the differential steering wheel. At the same time, the current angle and angular velocity can be controlled based on the motor speed control value, further improving the accuracy of the differential steering wheel during operation, ensuring that it can accurately reach the target position, and enhancing the overall performance of the equipment operation.

[0101] As Figure 4 shown, it is a system block diagram of a differential steering wheel control system based on LQR provided by an embodiment of the present invention. The control system includes:

[0102] An acquisition and reception module, configured to acquire the current angle and current angular velocity of the differential steering wheel, and at the same time receive the target angle and target speed of the differential steering wheel;

[0103] A difference calculation module, configured to calculate the current angle difference based on the current angle and the target angle;

[0104] An LQR controller calculation module, configured to input the current angle difference and the current angular velocity into the LQR controller, calculate the angular acceleration control amount and convert it into a motor speed control increment;

[0105] A control amount adjustment module, configured to adjust the overall motor speed control amount based on the target speed and the current angle difference according to the motor speed control increment;

[0106] A driver control module, configured to obtain the maximum motor speed parameter, and calculate the motor speed control value based on the target speed and the adjusted overall motor speed control amount and transmit it to the driver.

[0107] Figure 4 The device in the shown embodiment can correspondingly be used to execute the steps in the method embodiment shown in Figure 1 The implementation principle and technical effects are similar, and will not be elaborated here.

[0108] An electronic device includes a memory and a processor. A computer program is stored in the memory. When the processor runs the computer program stored in the memory, the processor executes the steps of a differential steering wheel control method based on LQR as described in any one of the above.

[0109] As Figure 5 shown, it is a schematic hardware structure diagram of an electronic device provided by an embodiment of the present invention. The electronic device 50 includes: a processor 51, a memory 52, and a computer program; where

[0110] A memory 52 for storing the computer program, and the memory may also be a flash memory. The computer program is, for example, an application program, a functional module, etc. for implementing the above method.

[0111] A processor 51 for executing the computer program stored in the memory to implement each step performed by the device in the above method. For specific details, reference may be made to the relevant descriptions in the foregoing method embodiments.

[0112] Optionally, the memory 52 may be either independent or integrated with the processor 51.

[0113] When the memory 52 is a device independent of the processor 51, the device may further include:

[0114] A bus 53 for connecting the memory 52 and the processor 51.

[0115] A readable storage medium stores a computer program, and when the computer program is executed by a processor, it is used to implement the steps of a differential steering wheel control method based on LQR as described in any one of the above.

[0116] Among them, the readable storage medium may be a computer storage medium or a communication medium. The communication medium includes any medium facilitating the transmission of a computer program from one place to another. The computer storage medium may be any available medium accessible by a general-purpose or special-purpose computer. For example, the readable storage medium is coupled to the processor, enabling the processor to read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium may also be a component of the processor. The processor and the readable storage medium may be located in an application specific integrated circuit (ASIC). Additionally, the ASIC may be located in a user device. Of course, the processor and the readable storage medium may also exist as discrete components in a communication device. The readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, and an optical data storage device, etc.

[0117] The present invention also provides a program product, which includes execution instructions stored in a readable storage medium. At least one processor of the device can read the execution instructions from the readable storage medium, and at least one processor executing the execution instructions causes the device to implement the methods provided by the above various embodiments.

[0118] In the embodiments of the above device, it should be understood that the processor can be a central processing unit (CPU for short), or other general-purpose processors, digital signal processors (DSP for short), application specific integrated circuits (ASIC for short), etc. The general-purpose processor can be a microprocessor or any conventional processor, etc. The steps of the method disclosed in combination with the present invention can be directly embodied as being executed by a hardware processor, or executed by a combination of hardware and software modules in the processor.

[0119] Through the introduction of the above embodiments, the present invention can collect the current angle and current angular velocity of the differential steering wheel through the differential steering wheel control method based on LQR, and at the same time receive the target angle and target speed of the differential steering wheel; calculate the current angle difference based on the current angle and the target angle; input the current angle difference and the current angular velocity into the LQR controller, calculate the angular acceleration control amount and convert it into the motor speed control increment; based on the target speed and the current angle difference, adjust the overall motor speed control amount according to the motor speed control increment; obtain the maximum motor speed parameter, and calculate the motor speed control value based on the target speed and the adjusted overall motor speed control amount and transmit it to the driver, so that the speed and rotation angle of the differential steering wheel can be accurately controlled, effectively solving the problems of steering wheel vibration and unstable driver load existing in the existing control methods.

[0120] The present invention can establish a differential steering wheel motion model based on LQR, so that the steady-state angle tracking error of the differential steering wheel converges to zero, thereby effectively improving the control accuracy of the speed and rotation angle of the differential steering wheel. For differential steering wheels of different specifications and sizes, the method of the present invention has good adaptability, does not need to rely on experience to adjust control parameters, reduces the development cost and debugging difficulty, and saves development time. The present invention fully considers the overall rotation acceleration and deceleration characteristics of the steering wheel, effectively avoids the problems of steering wheel vibration and unstable driver load, improves the stability and reliability of equipment operation, and reduces the equipment maintenance frequency.

[0121] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A differential steering wheel control method based on LQR, characterized in that: The control method comprises: Collecting the current angle and current angular velocity of the differential steering wheel, and simultaneously receiving the target angle and target speed of the differential steering wheel; Calculate a current angle difference based on the current angle and the target angle; Input the current angle difference and the current angular velocity into the LQR controller, calculate the angular acceleration control amount and convert it into a motor speed control increment; Based on the target speed and the current angle difference, adjusting the overall control amount of the motor speed according to the motor speed control increment; Acquire the maximum speed parameter of the motor, and calculate the motor speed control value based on the target speed and the adjusted overall motor speed control amount, and transmit it to the driver; The current angle and the current angular velocity are collected by an absolute encoder on the wheelset frame of the differential steering wheel; The calculation process of the angular acceleration control amount is as follows: The expression of the continuous-time linear state-space model of the LQR controller is as follows: In the formula, represents the rate of change of the system state vector at time t; represents the system state vector at time t; represents the control input vector at time t; A represents the state matrix; B represents the input matrix; At the time t, the current angle difference and the current angular velocity As the system state vector , and the angular acceleration control amount As the control input vector , setting the control time interval to M, then the system state vector at time t+1 is , the corresponding calculation formula is as follows: After transforming the above formula, we get: In the formula, Indicates the current angle difference and the current angular velocity Angle difference control function; Indicates the current angle difference and the current angular velocity Angular velocity control function; By solving the formula The Jacobian matrix of the state matrix is ​​obtained , the input matrix ; Set the state weight matrix of the LQR controller , control weight matrix ,in, Indicates control parameters; The final control law of the LQR controller is set as ; Feedback gain matrix ,in, represents the transposed matrix of the input matrix B, Representation Matrix The inverse matrix of the intermediate matrix P satisfies the formula ,in, represents the transposed matrix of the state matrix A; represents the inverse matrix of the control weight matrix R; By solving the formula , obtain the intermediate matrix P, the feedback gain matrix K and the control input vector , and the control input vector That is, the angular acceleration control amount .

2. The LQR-based differential steering wheel control method according to claim 1, characterized in that: The calculation formula for converting the angular acceleration control amount into the motor speed control increment is as follows: In the formula, Indicates the motor speed control increment; represents the angular acceleration control amount; M represents the control time interval; d represents the turning radius of the differential steering wheel; R represents the radius of the differential steering wheel.

3. The LQR-based differential steering wheel control method according to claim 1, characterized in that: The adjusting the overall control amount of the motor speed according to the motor speed control increment based on the target speed and the current angle difference specifically includes: Determine whether the target speed is 0. If the target speed is not 0, the overall control amount of the motor speed after adjustment is ,in, Indicates the overall motor speed control amount before adjustment. represents the motor speed control increment; if the target speed is 0, it is determined whether the current angle difference is less than 0.2°. If the current angle difference is less than 0.2°, the overall motor speed control amount after adjustment is ; If the current angle difference is greater than or equal to 0.2°, determine whether the current angle difference is greater than 2°. If the current angle difference is greater than 2°, adjust the overall motor speed control amount. If the current angle difference is less than or equal to 2°, the overall motor speed control amount after adjustment is .

4. The LQR-based differential steering wheel control method according to claim 1, characterized in that: The step of obtaining the maximum motor speed parameter, and calculating the motor speed control value based on the target speed and the adjusted motor speed overall control amount, and transmitting the value to the driver specifically includes: Set the maximum speed parameter of the motor to The target speed is , if the overall control amount of the motor speed after adjustment is satisfy , then limit , otherwise no restriction ; The differential steering wheel has motor No. 1 and motor No. 2 built in, and the corresponding motor speed control values ​​are respectively and ; The motor speed control value and The signals are transmitted to the driver No. 1 corresponding to the motor No. 1 and the driver No. 2 corresponding to the motor No. 2 respectively.

5. The LQR-based differential steering wheel control method according to claim 1, characterized in that: The method further includes controlling the current angle and the current angular velocity through the driver based on the motor speed control value.

6. A differential steering wheel control system based on LQR, applied to a differential steering wheel control method based on LQR as claimed in any one of claims 1 to 5, characterized in that: The control system comprises: The acquisition receiving module is used to acquire the current angle and current angular velocity of the differential steering wheel, and simultaneously receive the target angle and target speed of the differential steering wheel; A difference calculation module, used for calculating a current angle difference based on the current angle and the target angle; An LQR controller calculation module is used to input the current angle difference and the current angular velocity into the LQR controller, calculate the angular acceleration control amount and convert it into a motor speed control increment; A control amount adjustment module, configured to adjust the overall control amount of the motor speed according to the motor speed control increment based on the target speed and the current angle difference; The driver control module is used to obtain the maximum speed parameter of the motor, and calculate the motor speed control value based on the target speed and the adjusted overall control amount of the motor speed, and transmit the value to the driver.

7. An electronic device comprising a memory and a processor, wherein a computer program is stored in the memory, wherein: When the processor runs the computer program stored in the memory, the processor executes the steps of the LQR-based differential steering wheel control method as described in any one of claims 1 to 5.

8. A readable storage medium having a computer program stored therein, characterized in that: When the computer program is executed by a processor, it is used to implement the steps of a LQR-based differential steering wheel control method as described in any one of claims 1-5.

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