Zero-force control method and device for photovoltaic support

Abstract

The embodiment of the invention provides a zero-force control method for a photovoltaic support, the photovoltaic support is provided with a joint shaft, the joint shaft is used for adjusting the posture of a photovoltaic module, and the zero-force control method comprises the following steps: acquiring the speed and gravitational torque of the joint shaft; determining the friction torque of the joint shaft based on the speed of the joint shaft and a pre-trained friction model; determining a compensation torque according to the friction torque and the gravitational torque; and the motor is controlled to output the compensation torque so as to adjust the output torque of the joint shaft. According to the technical scheme provided by the embodiment of the invention, the photovoltaic bracket does not generate or generates extremely small resistance in the rotation process, so that zero-force rotation control of the photovoltaic bracket is realized.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of photovoltaic technology, and in particular to a zero-force control method, apparatus, computer equipment, computer-readable storage medium, and computer program product for a photovoltaic bracket. Background Art

[0002] With the global popularity of solar power generation, the demand for photovoltaic modules to generate electricity continues to increase. Photovoltaic modules can use fixed brackets or tracking brackets. The angle of fixed brackets is pre-set and cannot be adjusted. Tracking brackets can adjust the angle according to the sun's daily movement and seasonal changes to maximize the capture of solar radiation.

[0003] However, tracking brackets still have the following defects: (1) During the installation, debugging, and subsequent maintenance and cleaning stages, it is necessary to frequently send commands for specifying angles and perform multiple debugging to achieve the preset posture, which is a very time-consuming process; (2) Adjusting the bracket to the preset posture requires a complex control panel or programming method, which is complicated to operate, inconvenient for human-computer interaction, and requires high operator skills; (3) Adjusting the bracket through the operating interface or joystick is not intuitive, has poor flexibility, and is prone to misoperation, thereby increasing safety risks.

[0004] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Summary of the invention

[0005] The embodiments of the present application provide a zero-force control method, apparatus, computer equipment, computer-readable storage medium, and computer program product for a photovoltaic bracket to solve or alleviate one or more of the technical problems raised above.

[0006] One aspect of an embodiment of the present application provides a zero-force control method for a photovoltaic bracket, wherein the photovoltaic bracket is provided with a joint axis, and the joint axis is used to adjust the posture of the photovoltaic assembly. The zero-force control method includes: Obtaining the velocity and gravity torque of the joint axis; Determining the friction torque of the joint axis based on the velocity of the joint axis and a pre-trained friction model; Determining a compensation torque according to the friction torque and the gravity torque; The motor is controlled to output the compensation torque to adjust the output torque of the joint shaft.

[0007] Optionally, the photovoltaic support further includes a force sensor, and the force sensor is connected to the photovoltaic assembly; obtaining the gravity torque of the joint axis includes: Acquiring an initial gravity moment through the force sensor; Performing filtering processing on the initial gravity moment to obtain the gravity moment; Wherein, the force sensor comprises a six-dimensional force sensor.

[0008] Optionally, obtaining the gravity torque of the joint axis includes: Obtaining the weight of the photovoltaic assembly and the angle of the joint axis; Determining a state of the photovoltaic assembly according to the angle of the joint axis, wherein the state includes a tilted state or a horizontal state; When the photovoltaic assembly is in a tilted state, determining the gravity moment according to the weight of the photovoltaic assembly and the angle of the joint axis; When the photovoltaic assembly is in a horizontal state, the gravity moment is determined according to the weight of the photovoltaic assembly.

[0009] Optionally, the friction model is obtained by the following operations: Determine a test angle interval and a test speed interval, wherein the test angle interval includes a plurality of test angles, and the test speed interval includes a plurality of test speeds; For each test speed, the following operations are performed: in the test angle interval, the joint axis is controlled to move in a clockwise direction and a counterclockwise direction respectively according to the current test speed; during the clockwise movement, the first output torque of the joint axis at each test angle is obtained; during the counterclockwise movement, the second output torque of the joint axis at each test angle is obtained; according to the first output torque and the second output torque corresponding to each of the multiple test angles, the friction torque corresponding to the current test speed is determined; Model training is performed based on the friction torques corresponding to the multiple test speeds to obtain the friction model.

[0010] Optionally, determining the friction torque corresponding to the current test speed according to the first output torque and the second output torque corresponding to each of the multiple test angles includes: Obtain the difference between the first output torque and the second output torque at each test angle; Determining the friction torque at each test angle according to the difference; Determining an average friction torque based on the friction torques corresponding to the multiple test angles; The average friction torque is determined as the friction torque corresponding to the current test speed.

[0011] Optionally, the friction model is obtained by the following operations: Determine a test angle interval and a test speed interval, wherein the test angle interval includes a plurality of test angles, and the test speed interval includes a plurality of test speeds; In the test angle interval, the joint axis is controlled to gradually increase from a minimum test speed to a maximum test speed to move in a clockwise direction, and the joint axis is controlled to gradually decrease from a maximum test speed to a minimum test speed to move in a counterclockwise direction, and the test speed corresponding to each test angle in the clockwise movement and the counterclockwise movement is equal; During the clockwise movement, a first output torque of the joint axis at each test angle is obtained; during the counterclockwise movement, a second output torque of the joint axis at each test angle is obtained; Determine the friction torque of the test speed corresponding to the test angle based on the first output torque and the second output torque of each test angle; Model training is performed based on the friction torques of the multiple test speeds to obtain the friction model.

[0012] Optionally, determining the compensation torque according to the friction torque and the gravity torque includes: Obtaining the angular acceleration and inertia matrix of the joint axis; Determining the inertia moment of the joint axis according to the angular acceleration and the inertia matrix of the joint axis; The compensation torque is determined according to the inertia torque, the friction torque and the gravity torque.

[0013] Optionally, determining the compensation torque according to the friction torque and the gravity torque includes: Determining centrifugal force and Coriolis force torque based on the speed of the joint axis; The compensation torque is determined based on the centrifugal force and Coriolis force term torque, the friction torque and the gravity torque.

[0014] Optionally, determining the compensation torque according to the friction torque and the gravity torque includes: The compensation torque is determined based on the inertia torque, the centrifugal force and Coriolis force torque, the friction torque and the gravity torque.

[0015] Another aspect of the embodiments of the present application provides a zero-force control device for a photovoltaic support, the device comprising: An acquisition module, used for acquiring the velocity and gravity torque of the joint axis; A first determination module, configured to determine the friction torque of the joint axis based on the speed of the joint axis and a pre-trained friction model; A second determination module, configured to determine a compensation torque according to the friction torque and the gravity torque; The control module is used to control the motor to output the compensation torque to adjust the output torque of the joint shaft.

[0016] Another aspect of an embodiment of the present application provides a computer device, including: at least one processor; and a memory communicatively coupled to the at least one processor; Wherein: the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method as described above.

[0017] Another aspect of an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and when the computer instructions are executed by a processor, the method described above is implemented.

[0018] Another aspect of an embodiment of the present application provides a computer program product, including a computer program, which implements the method described above when executed by a processor.

[0019] The above technical solution adopted in the embodiment of the present application may have the following advantages: The photovoltaic module is installed on a photovoltaic bracket, and the photovoltaic bracket includes a connecting rod and a joint shaft. The connecting rod is used to support the photovoltaic module, and the joint shaft is used to adjust the posture of the photovoltaic module. Apply external force to drive the joint shaft of the photovoltaic bracket to rotate. During the rotation process: obtain the speed and gravity torque of the joint shaft, and obtain the friction torque of the joint shaft based on the speed of the joint shaft and a pre-trained friction model, so as to determine the compensation torque. Control the motor to output the compensation torque to compensate for gravity and friction in real time during the rotation process, so as to adjust the output torque of the joint shaft to zero or close to zero, so as to achieve zero-force rotation control of the photovoltaic bracket. It can be seen that the embodiments of the present application can achieve the following beneficial effects: (1) Zero-force rotation control of the photovoltaic bracket is realized, and the operation is intuitive and flexible. The photovoltaic bracket generates no or very little resistance during the rotation process, thereby avoiding injuries to the operator due to misoperation or sudden rotation of the photovoltaic bracket, and improving operational safety.

[0020] (2) Supports the operator to directly rotate the photovoltaic bracket to the preset posture, simplifying the operation and shortening the adjustment time.

[0021] (3) Improve the convenience of human-computer interaction and reduce the requirements for operators. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings exemplarily illustrate the embodiments and constitute a part of the specification, and together with the text description of the specification, are used to explain the exemplary implementation of the embodiments. The embodiments shown are for illustrative purposes only and do not limit the scope of the claims. In all drawings, the same reference numerals refer to similar but not necessarily identical elements.

[0023] Figure 1 A flowchart of a zero-force control method for a photovoltaic support according to Embodiment 1 of the present application is schematically shown; Figure 2 The photovoltaic bracket according to the first embodiment of the present application is schematically shown; Figure 3 Schematically shows Figure 1 Flow chart of sub-steps of step S100; Figure 4 Schematically shows Figure 1 Flow chart of sub-steps of step S100; Figure 5 The flowchart of obtaining the friction model according to the first embodiment of the present application is schematically shown; Figure 6 Schematically shows Figure 5 The sub-step flow chart of S5024; Figure 7 Another acquisition flow chart of the friction model according to the first embodiment of the present application is schematically shown; Figure 8 This is an application example diagram of the zero-force control method for a photovoltaic support according to the first embodiment of the present application; Fig. 9 A block diagram of a zero-force control device for a photovoltaic support according to the second embodiment of the present application is schematically shown; and Fig.10 The hardware architecture diagram of the computer device according to the third embodiment of the present application is schematically shown. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0025] It should be noted that the descriptions involving "first", "second", etc. in the embodiments of the present application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0026] In the description of the present application, it should be understood that the numerical labels before the steps do not indicate the order in which the steps are executed, but are only used to facilitate the description of the present application and to distinguish each step, and therefore should not be understood as a limitation on the present application.

[0027] First, the following terms are explained: MCU (Micro-controller Unit): microcontroller unit.

[0028] Stribeck model: The Stribeck model can be used to describe the effect of lubrication conditions on the friction coefficient.

[0029] LuGre model: LuGre model can be used to describe the relationship between friction and motion speed.

[0030] Centrifugal force: A fictitious force on an object due to its rotation in a rotating reference frame, causing the object to appear to move away from the center of rotation.

[0031] Coriolis force (also known as Coriolis force, Coriolis force): The virtual force generated by the movement of an object in a rotating reference frame causes the object's trajectory to deflect.

[0032] Six-axis force sensor (or six-degree-of-freedom force sensor): can simultaneously measure the linear force of an object in three directions (along the X, Y, and Z axes) and the torque in three directions (around the X, Y, and Z axes).

[0033] DC (Direct Current): direct current.

[0034] The embodiment of the present application provides a zero-force control technical solution for a photovoltaic bracket. In this technical solution: (1) the operator is supported to directly rotate the joint axis of the photovoltaic bracket to the ideal posture, simplifying the operation and shortening the debugging time; (2) the operation process is simplified, the convenience of human-computer interaction is improved, the operator's training time is shortened, and the requirements for the operator are reduced; (3) the zero-force rotation control of the photovoltaic bracket is realized, and the photovoltaic bracket generates no or very little resistance during the rotation process, thereby avoiding damage to the operator due to misoperation or sudden rotation of the photovoltaic bracket, and improving the safety of operation. See below for details.

[0035] The technical solutions of the present application are described below through multiple embodiments. It should be noted that these embodiments can be implemented in a variety of different forms and should not be construed as being limited to the embodiments described here.

[0036] Embodiment 1 Figure 1 A flow chart of a zero-force control method for a photovoltaic support according to the first embodiment of the present application is schematically shown.

[0037] like Figure 2 As shown, the photovoltaic support may include a connecting rod 1, and the connecting rod 1 may be provided with a joint shaft 2. The number of the joint shafts 2 may be set according to actual needs. Figure 2 A dual-axis photovoltaic bracket is schematically shown, in which one joint axis 21 can be set at the top of the connecting rod, and the other joint axis 22 can be set at the middle or bottom of the connecting rod. The joint axis 21 can be used to adjust the tilt angle (elevation angle) of the photovoltaic module. The joint axis 22 can be used to adjust the azimuth angle of the photovoltaic module, that is, the direction it is facing (such as east, west, south, and north). The photovoltaic bracket can be used to install photovoltaic modules, and the zero-force control method of the embodiment of the present application can be used to control the rotation of the photovoltaic bracket, thereby adjusting the posture of the photovoltaic module. The zero-force control method is exemplarily introduced below.

[0038] like Figure 1 As shown, the zero-force control method for a photovoltaic support may include steps S100 to S106, wherein: Step S100, obtaining the velocity and gravity torque of the joint axis.

[0039] Step S102 , determining the friction torque of the joint axis based on the speed of the joint axis and a pre-trained friction model.

[0040] Step S104: determining a compensation torque according to the friction torque and the gravity torque.

[0041] Step S106, controlling the motor to output the compensation torque to adjust the output torque of the joint shaft.

[0042] The zero-force control method for a photovoltaic bracket provided in this embodiment installs a photovoltaic module on a photovoltaic bracket, and the photovoltaic bracket includes a connecting rod and a joint shaft. The connecting rod is used to support the photovoltaic module, and the joint shaft is used to adjust the posture of the photovoltaic module. Apply an external force to drive the joint shaft of the photovoltaic bracket to rotate. During the rotation process: obtain the speed and gravity torque of the joint shaft, and obtain the friction torque of the joint shaft based on the speed of the joint shaft and a pre-trained friction model to determine the compensation torque. Control the motor to output the compensation torque to compensate for gravity and friction in real time during the rotation process, so as to adjust the output torque of the joint shaft to zero or close to zero, so as to achieve zero-force rotation control of the photovoltaic bracket. It can be seen that the embodiments of the present application can achieve the following beneficial effects: Zero-force rotation control of the photovoltaic bracket is realized, and the operation is intuitive and flexible. The photovoltaic bracket generates no or very little resistance during the rotation process, thereby avoiding injuries to the operator due to misoperation or sudden rotation of the photovoltaic bracket and improving operational safety; it supports the operator to directly rotate the photovoltaic bracket to a preset posture, simplifies the operation, and shortens the adjustment time; improves the convenience of human-computer interaction and reduces the requirements for the operator.

[0043] The following combination Figure 1 , each step in steps S100~S106 and other optional steps are explained in detail.

[0044] Step S100, obtaining the velocity and gravity torque of the joint axis.

[0045] The joint axis is the actuator of the photovoltaic bracket and can be used to control the posture of the photovoltaic module. The microcontroller unit (MCU) of the photovoltaic bracket can drive the joint axis by controlling the motor. The motor can use a DC motor (DC brushless motor or DC brushed motor), a servo motor, a stepper motor, etc. Taking the DC brushless motor as an example, in order to meet the needs of the photovoltaic power station, the switching power supply can be powered by DC28V~60V. In some embodiments, a single photovoltaic module can also be directly used to connect the motor power supply, which is more convenient.

[0046] Exemplarily, the speed of the joint axis can be directly acquired through encoder differential or motor driver, and the gravity torque of the joint axis can be acquired through force sensor, strain gauge, etc. Some exemplary solutions are provided below.

[0047] In an optional embodiment, if Figure 2 As shown, the photovoltaic support may further include a force sensor 3, which may be disposed at the end of the photovoltaic support and connected to the photovoltaic assembly to detect the force applied to the photovoltaic support, such as the pressure exerted by the photovoltaic assembly on the photovoltaic support. Figure 3 As shown, step S100 may include: Step S300, obtaining an initial gravity moment through the force sensor. The force sensor may include a six-dimensional force sensor.

[0048] Step S302: filtering the initial gravity moment to obtain the gravity moment.

[0049] For example, the initial gravity moment can be directly obtained through the six-dimensional force sensor. Due to factors such as the environment (such as wind and snow), mechanical wear, and load imbalance, the photovoltaic bracket may vibrate during rotation, thereby interfering with the output value of the six-dimensional force sensor and causing a large error. Therefore, the initial gravity moment output by the six-dimensional force sensor can be filtered, such as sliding weighted filtering, Kalman filtering, etc., to obtain a more accurate gravity moment.

[0050] In this embodiment, the initial gravity moment is directly read by the six-dimensional force sensor, and the gravity moment is obtained through filtering, which can reduce errors and improve the system response speed.

[0051] In an optional embodiment, if Figure 4 As shown, step S100 may include: Step S400, obtaining the weight of the photovoltaic assembly and the angle of the joint axis.

[0052] Step S402: determining the state of the photovoltaic assembly according to the angle of the joint axis, wherein the state includes a tilted state or a horizontal state.

[0053] Step S404, when the photovoltaic assembly is in a tilted state, determining the gravity moment according to the weight of the photovoltaic assembly and the angle of the joint axis.

[0054] Step S406 , when the photovoltaic assembly is in a horizontal state, determining the gravity moment according to the weight of the photovoltaic assembly.

[0055] For example, the weight of the photovoltaic module can be obtained through a force sensor, or the weight of the photovoltaic module can be estimated in advance based on the size and model of the photovoltaic module to further speed up the system response speed. The angle (also called position) of the joint axis can be obtained in a variety of ways, such as: gyroscope, tilt sensor, geometric algorithm. According to the angle of the joint axis, the state of the photovoltaic module (tilted state or horizontal state) can be determined. If the photovoltaic module is in a horizontal state, the gravity torque can be directly determined based on the weight of the photovoltaic module. If the photovoltaic module is in a tilted state, the gravity torque can be calculated based on the angle of the joint axis and the weight of the photovoltaic module.

[0056] In this embodiment, the gravity moment is determined according to the angle of the joint axis, which can improve the calculation accuracy, obtain a more accurate gravity moment, and effectively reduce the error.

[0057] In some embodiments, the gravity torque measured by the six-dimensional force sensor may be cross-validated with the gravity torque calculated based on the joint axis angle to further improve the accuracy of the gravity torque.

[0058] To achieve zero force control, it is necessary to accurately estimate the total external force on the joint axis. The total external force mainly includes gravity and friction. The above embodiments exemplarily introduce how to obtain the gravity torque of the joint axis. The following will exemplarily introduce how to obtain the friction force of the joint axis.

[0059] Step S102 , determining the friction torque of the joint axis based on the speed of the joint axis and a pre-trained friction model.

[0060] The friction force on the joint axis is very complex and difficult to model accurately. It can be approximated as a function of the joint axis speed. There are many ways to model the friction force of the joint axis, such as: polynomial, Stribeck model, LuGre model, Coulomb viscous friction model, etc. The following will take the static LuGre model as an example to model the friction force of the joint axis. This model can comprehensively consider factors such as the Stribeck effect, hysteresis and spring, and is more in line with the characteristics of the friction force on the joint axis. Exemplarily, the relationship between the joint axis speed and friction force of the model can be expressed as follows: ; in, is the friction force of the joint axis, is the velocity of the joint axis, and a, b, c, d are the parameters to be estimated.

[0061] It can be seen that the original data required by the model are the speed of the joint axis and the corresponding friction data. As mentioned above, the speed of the joint axis can be directly obtained through the motor driver or encoder differential. The friction force of the joint axis can be solved based on the friction torque. However, the data related to the torque is only the output torque of the joint axis based on the motor current, and the friction torque cannot be directly separated. The principle of extracting friction can refer to the following formula: ; in, is the output torque of the joint axis, is the moment of inertia, are the centrifugal force and Coriolis force torque, is the gravitational moment, is the friction torque.

[0062] In practical applications, when a single joint axis is moving at a constant speed, the inertia moment, centrifugal force and Coriolis force term torque can be basically zero, but there are still gravity torque and friction torque mixed together. Therefore, the friction torque can be extracted from the output torque through static analysis, dynamic analysis, etc. to solve the friction force. The model is trained based on friction and speed, and the parameters a, b, c, d of the model are determined to obtain a usable friction model. An exemplary scheme is provided below.

[0063] In an optional embodiment, if Figure 5 As shown, the friction model can be obtained by the following steps: Step S500: determining a test angle interval and a test speed interval, wherein the test angle interval includes a plurality of test angles, and the test speed interval includes a plurality of test speeds.

[0064] Step S502: for each test speed, perform the following operations: Step S5021: In the test angle range, the joint axis is controlled to move in a clockwise direction and a counterclockwise direction respectively according to the current test speed.

[0065] Step S5022: During the clockwise movement, the first output torque of the joint axis at each test angle is obtained.

[0066] Step S5023: During the counterclockwise movement, the second output torque of the joint axis at each test angle is obtained.

[0067] Step S5024: Determine the friction torque corresponding to the current test speed according to the first output torque and the second output torque corresponding to each of the multiple test angles.

[0068] Step S504: Perform model training based on the friction torques corresponding to the multiple test speeds to obtain the friction model.

[0069] In practical applications, when a single joint axis rotates back and forth at a certain speed, such as 30~60°, 60~30°, the corresponding gravity torque at any position with the same angle (such as 45°) is equal, and the friction torque is equal in magnitude and opposite in direction. This feature can be used to obtain the friction torque at twice the speed. For example, the test angle interval (such as 30~60°, -180~180°, 0~360°, etc.) and the test speed interval can be set according to the needs. The test angle interval can include multiple test angles (such as: each test angle differs by 1°, each test angle differs by 5°), and the test speed interval can also include multiple different test speeds. For each test speed, the following operations can be performed to obtain the friction torque corresponding to the test speed. Specifically, the joint axis can be controlled to rotate back and forth at a constant speed and uniform speed within the test angle interval according to the current test speed, that is, clockwise and counterclockwise. During the round trip process, the output torque of the joint axis at each test angle is recorded, that is, the first output torque and the second output torque. Based on the first output torque and the second output torque of multiple test angles, the friction torque corresponding to the current test speed can be determined. According to each test speed and the corresponding friction torque, multiple data pairs are determined, and these data pairs are used as training samples for model training to obtain a friction model.

[0070] In this embodiment, by recording the output torque of the joint axis when it moves back and forth at a uniform speed in the complete test angle range at different speeds, a more comprehensive and accurate friction torque can be obtained, and the training samples can be enriched, thereby obtaining a more accurate and reliable friction model.

[0071] In an optional embodiment, if Figure 6 As shown, step S5024 may include: Step S600, obtaining the difference between the first output torque and the second output torque at each test angle.

[0072] Step S602: determining the friction torque at each test angle according to the difference.

[0073] Step S604: determining an average friction torque based on the friction torques corresponding to the multiple test angles.

[0074] Step S606: determine the average friction torque as the friction torque corresponding to the current test speed.

[0075] Exemplarily, the difference between the first output torque and the second output torque at each test angle can be used to obtain the difference at each test angle. As described above, the difference is twice the friction torque, so the friction torque at each test angle can be determined. The average friction torque corresponding to each of the multiple test angles is averaged to obtain the average friction torque, which is determined as the friction torque corresponding to the current test speed.

[0076] In this embodiment, the friction torque of the current test speed is determined by taking the average value of the differences of multiple test angles, which can reduce errors and noise interference and further enhance accuracy.

[0077] In an optional embodiment, if Figure 7 As shown, the friction model can also be obtained by the following operations: Step S700: determining a test angle interval and a test speed interval, wherein the test angle interval includes a plurality of test angles, and the test speed interval includes a plurality of test speeds.

[0078] Step S702, in the test angle range, control the joint axis to gradually increase from the minimum test speed to the maximum test speed to move in the clockwise direction, and control the joint axis to gradually decrease from the maximum test speed to the minimum test speed to move in the counterclockwise direction, and the test speed corresponding to each test angle in the clockwise movement and the counterclockwise movement is equal.

[0079] Step S704, during the clockwise movement, obtaining the first output torque of the joint axis at each test angle; during the counterclockwise movement, obtaining the second output torque of the joint axis at each test angle.

[0080] Step S706: Determine the friction torque of the test speed corresponding to the test angle based on the first output torque and the second output torque of each test angle.

[0081] Step S708: Perform model training based on the friction torques of the multiple test speeds to obtain the friction model.

[0082] In practical applications, in order to simplify the operation and improve efficiency, the friction torque of different joint axis speeds can be obtained through one experiment. For example, the joint axis can be controlled to gradually increase from the minimum test speed to the maximum test speed in the test angle interval to move clockwise (such as from 30~60°). Control the joint axis to gradually decrease from the maximum test speed to the minimum test speed in the test angle interval. The test speed of the same test angle in the round-trip motion is the same. In order to further reduce errors and noise interference, each test speed can correspond to the same uniform motion interval in the round-trip process, for example: in the first clock motion process, 30~35° corresponds to test speed A, 35~40° corresponds to test speed B, A<B; in the second clock motion process, 40~35° corresponds to test speed B, 35~30° corresponds to test speed A, B>A. The friction torque of each test angle can be obtained according to the first output torque and the second output torque of each test angle. The friction torque of each test angle in the uniform motion interval is averaged to obtain the friction torque corresponding to the test speed in the uniform motion interval. The friction model can be obtained by training the model based on multiple test speeds and their corresponding friction torques.

[0083] In this embodiment, a single joint axis is set to speed up and slow down to perform reciprocating motion within a test angle range, and the friction torque of different joint axis speeds can be obtained in one experiment, which can improve efficiency, simplify operation, reduce errors and optimize system performance.

[0084] In practical applications, the relationship curve between friction and joint axis speed is close to a straight line. Therefore, the Coulomb viscous friction model (similar to the linear function y=kx+b) can be used for fitting to more accurately reflect the actual situation. In addition, several sets of low-speed experiments can be added to further improve data accuracy.

[0085] By inputting the acquired joint axis velocity into the friction model pre-trained by any of the above embodiments, the friction force of the joint axis can be obtained, and then the friction torque can be calculated.

[0086] Step S104: determining a compensation torque according to the friction torque and the gravity torque.

[0087] The external forces acting on the joint axis during rotation are mainly gravity and friction. Therefore, the supplementary torque that the motor needs to output can be determined based on the friction torque and gravity torque to compensate for the gravity and friction for the joint axis in real time. The joint axis will also be affected by other forces during rotation, such as inertia, centrifugal force, and Coriolis force, which may cause the motion state of the joint axis to change, affecting its stability and control accuracy. In order to improve the zero-force control effect, these forces can also be compensated in real time. Several exemplary schemes are provided below.

[0088] In an optional embodiment, step S104 may include: acquiring the angular acceleration and inertia matrix of the joint axis, determining the inertia moment of the joint axis according to the angular acceleration and inertia matrix of the joint axis, and determining the compensation torque according to the inertia moment, the friction torque and the gravity torque.

[0089] In this embodiment, the angular acceleration and inertia matrix of the joint axis can be obtained. Among them, the inertia matrix can be determined based on the center of mass position of the connecting rod, the mass of the connecting rod, etc. According to the product of the joint axis and the inertia matrix, the inertia moment of the joint axis can be determined. Combining the inertia moment, friction moment and gravity moment, the compensation torque can be determined. Taking the inertia moment into account in the compensation torque can optimize the zero-force control effect.

[0090] In an optional embodiment, step S104 may include: determining the centrifugal force and Coriolis force term torque according to the speed of the joint axis; and determining the compensation torque according to the centrifugal force and Coriolis force term torque, the friction torque and the gravity torque.

[0091] In this embodiment, the speed of the joint axis can be obtained to determine the centrifugal force and the Coriolis force torque. Taking the centrifugal force and the Coriolis force into account in the compensation torque can further improve the effect of zero-force control.

[0092] In an optional embodiment, step S104 may include: determining the compensation torque according to the inertia torque, the centrifugal force and Coriolis force term torque, the friction torque and the gravity torque.

[0093] In this embodiment, the compensation torque is determined based on the inertia torque, centrifugal force and Coriolis force torque, friction torque and gravity torque, which can improve the accuracy and stability of zero-force control.

[0094] Step S106, controlling the motor to output the compensation torque to adjust the output torque of the joint shaft.

[0095] Artificial external force is applied to drive the joint shaft of the photovoltaic bracket to rotate. During the rotation process, the MCU can control the motor to output compensation torque to compensate for gravity and friction in real time during the rotation process, thereby adjusting the output torque of the joint shaft to zero or close to zero, thereby achieving zero-force rotation control of the photovoltaic bracket. Figure 2 Taking the dual-axis photovoltaic bracket shown as an example, after determining the compensation torque of each joint axis, the motor output compensation torque can be controlled to achieve zero-force control.

[0096] In order to make this application easier to understand, the following Figure 8 An exemplary application is provided.

[0097] S1: Apply external force manually to rotate the photovoltaic bracket, obtain the gravity torque of the joint axis through the six-dimensional sensor, and obtain the speed of the joint axis directly through the motor driver or by encoder differential.

[0098] S2: Input the velocity of the joint axis into the pre-trained friction model to obtain the friction torque of the joint axis through the friction model.

[0099] S3: Determine a compensation torque based on the gravity torque and the friction torque.

[0100] S4: Control the motor output compensation torque to adjust the output torque of the joint shaft to zero or close to zero, and the photovoltaic module will rotate smoothly with the photovoltaic bracket under the action of external force.

[0101] In this exemplary application: (1) zero-force rotation control of the photovoltaic bracket is achieved, and the operation is intuitive and flexible. The photovoltaic bracket generates no or very little resistance during the rotation process, thereby avoiding injuries to the operator due to misoperation or sudden rotation of the photovoltaic bracket and improving operational safety; (2) the operator is supported to directly rotate the photovoltaic bracket to a preset posture, simplifying the operation and shortening the adjustment time; (3) the convenience of human-computer interaction is improved and the requirements for the operator are reduced.

[0102] Embodiment 2 Fig. 9 The block diagram of the zero-force control device for a photovoltaic support according to the second embodiment of the present application is schematically shown. The photovoltaic support is provided with a joint axis, and the joint axis is used to adjust the posture of the photovoltaic component. The zero-force control device can be divided into one or more program modules, and one or more program modules are stored in a storage medium and executed by one or more processors to complete the embodiment of the present application. The program module referred to in the embodiment of the present application refers to a series of computer program instruction segments that can perform specific functions. The following description will specifically introduce the functions of each program module in this embodiment. Fig. 9 As shown, the device 1000 may include: an acquisition module 1100, a first determination module 1200, a second determination module 1300 and a control module 1400, wherein: An acquisition module 1100 is used to acquire the velocity and gravity torque of the joint axis; A first determination module 1200 is used to determine the friction torque of the joint axis based on the speed of the joint axis and a pre-trained friction model; A second determining module 1300, configured to determine a compensation torque according to the friction torque and the gravity torque; The control module 1400 is used to control the motor to output the compensation torque to adjust the output torque of the joint axis.

[0103] As an optional embodiment, the photovoltaic bracket further includes a force sensor, and the force sensor is connected to the photovoltaic assembly; obtaining the gravity torque of the joint axis includes: Acquiring an initial gravity moment through the force sensor; Performing filtering processing on the initial gravity moment to obtain the gravity moment; Wherein, the force sensor comprises a six-dimensional force sensor.

[0104] As an optional embodiment, obtaining the gravity moment of the joint axis includes: Obtaining the weight of the photovoltaic assembly and the angle of the joint axis; Determining a state of the photovoltaic assembly according to the angle of the joint axis, wherein the state includes a tilted state or a horizontal state; When the photovoltaic assembly is in a tilted state, determining the gravity moment according to the weight of the photovoltaic assembly and the angle of the joint axis; When the photovoltaic assembly is in a horizontal state, the gravity moment is determined according to the weight of the photovoltaic assembly.

[0105] As an optional embodiment, the friction model is obtained by the following operations: Determine a test angle interval and a test speed interval, wherein the test angle interval includes a plurality of test angles, and the test speed interval includes a plurality of test speeds; For each test speed, the following operations are performed: in the test angle interval, the joint axis is controlled to move in a clockwise direction and a counterclockwise direction respectively according to the current test speed; during the clockwise movement, the first output torque of the joint axis at each test angle is obtained; during the counterclockwise movement, the second output torque of the joint axis at each test angle is obtained; according to the first output torque and the second output torque corresponding to each of the multiple test angles, the friction torque corresponding to the current test speed is determined; Model training is performed based on the friction torques corresponding to the multiple test speeds to obtain the friction model.

[0106] As an optional embodiment, determining the friction torque corresponding to the current test speed according to the first output torque and the second output torque corresponding to each of the multiple test angles includes: Obtain the difference between the first output torque and the second output torque at each test angle; Determining the friction torque at each test angle according to the difference; Determining an average friction torque based on the friction torques corresponding to the multiple test angles; The average friction torque is determined as the friction torque corresponding to the current test speed.

[0107] As an optional embodiment, the friction model is obtained by the following operations: Determine a test angle interval and a test speed interval, wherein the test angle interval includes a plurality of test angles, and the test speed interval includes a plurality of test speeds; In the test angle interval, the joint axis is controlled to gradually increase from a minimum test speed to a maximum test speed to move in a clockwise direction, and the joint axis is controlled to gradually decrease from a maximum test speed to a minimum test speed to move in a counterclockwise direction, and the test speed corresponding to each test angle in the clockwise movement and the counterclockwise movement is equal; During the clockwise movement, a first output torque of the joint axis at each test angle is obtained; during the counterclockwise movement, a second output torque of the joint axis at each test angle is obtained; Determine the friction torque of the test speed corresponding to the test angle based on the first output torque and the second output torque of each test angle; Model training is performed based on the friction torques of the multiple test speeds to obtain the friction model.

[0108] As an optional embodiment, determining the compensation torque according to the friction torque and the gravity torque includes: Obtaining the angular acceleration and inertia matrix of the joint axis; Determining the inertia moment of the joint axis according to the angular acceleration and the inertia matrix of the joint axis; The compensation torque is determined according to the inertia torque, the friction torque and the gravity torque.

[0109] As an optional embodiment, determining the compensation torque according to the friction torque and the gravity torque includes: Determining centrifugal force and Coriolis force torque based on the speed of the joint axis; The compensation torque is determined based on the centrifugal force and Coriolis force term torque, the friction torque and the gravity torque.

[0110] As an optional embodiment, determining the compensation torque according to the friction torque and the gravity torque includes: The compensation torque is determined based on the inertia torque, the centrifugal force and Coriolis force torque, the friction torque and the gravity torque.

[0111] Embodiment 3 Fig.10 The hardware architecture diagram of the computer device 10000 suitable for implementing the zero-force control method for a photovoltaic support according to the third embodiment of the present application is schematically shown. In some embodiments, the computer device 10000 may be a terminal device such as a smart phone, a wearable device, a tablet computer, a personal computer, a vehicle terminal, a game console, a virtual device, a workbench, a digital assistant, a set-top box, a robot, etc. In other embodiments, the computer device 10000 may be a rack server, a blade server, a tower server, or a cabinet server (including an independent server, or a server cluster composed of multiple servers), etc. Fig.10 As shown, the computer device 10000 includes but is not limited to: a memory 10010, a processor 10020, and a network interface 10030 that can communicate with each other through a system bus. Among them: The memory 10010 includes at least one type of computer-readable storage medium, and the readable storage medium includes flash memory, hard disk, multimedia card, card-type memory (such as SD or DX memory), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, magnetic disk, optical disk, etc. In some embodiments, the memory 10010 can be an internal storage module of the computer device 10000, such as a hard disk or memory of the computer device 10000. In other embodiments, the memory 10010 can also be an external storage device of the computer device 10000, such as a plug-in hard disk equipped on the computer device 10000, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. Of course, the memory 10010 can also include both the internal storage module of the computer device 10000 and its external storage device. In this embodiment, the memory 10010 is generally used to store the operating system and various application software installed on the computer device 10000, such as the program code of the zero-force control method for the photovoltaic support, etc. In addition, the memory 10010 can also be used to temporarily store various data that have been output or will be output.

[0112] In some embodiments, the processor 10020 may be a central processing unit (CPU), a controller, a microcontroller, a microprocessor, or other chips. The processor 10020 is generally used to control the overall operation of the computer device 10000, such as performing control and processing related to data interaction or communication with the computer device 10000. In this embodiment, the processor 10020 is used to run the program code stored in the memory 10010 or process data.

[0113] The network interface 10030 may include a wireless network interface or a wired network interface, and the network interface 10030 is generally used to establish a communication link between the computer device 10000 and other computer devices. For example, the network interface 10030 is used to connect the computer device 10000 to an external terminal through a network, and to establish a data transmission channel and a communication link between the computer device 10000 and the external terminal. The network may be a wireless or wired network such as an intranet, the Internet, the Global System of Mobile communication (GSM), Wideband Code Division Multiple Access (WCDMA), 4G network, 5G network, Bluetooth, Wi-Fi, etc.

[0114] It should be pointed out that Fig.10 Only a computer device having components 10010 - 10030 is shown, but it should be understood that implementation of all of the components shown is not a requirement, and more or fewer components may alternatively be implemented.

[0115] In this embodiment, the zero-force control method for a photovoltaic support stored in the memory 10010 may also be divided into one or more program modules and executed by one or more processors (such as processor 10020) to complete the embodiment of the present application.

[0116] Embodiment 4 An embodiment of the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the steps of the zero-force control method for a photovoltaic bracket in the embodiment are implemented.

[0117] In this embodiment, the computer-readable storage medium includes flash memory, hard disk, multimedia card, card-type memory (for example, SD or DX memory, etc.), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, disk, optical disk, etc. In some embodiments, the computer-readable storage medium may be an internal storage unit of a computer device, such as a hard disk or memory of the computer device. In other embodiments, the computer-readable storage medium may also be an external storage device of a computer device, 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 computer device. Of course, the computer-readable storage medium may also include both an internal storage unit of a computer device and an external storage device thereof. In this embodiment, the computer-readable storage medium is generally used to store an operating system and various application software installed on a computer device, such as a program code of a zero-force control method for a photovoltaic bracket in an embodiment, etc. In addition, the computer-readable storage medium may also be used to temporarily store various types of data that have been output or are to be output.

[0118] Embodiment 5 An embodiment of the present application also provides a computer program product, including a computer program, which implements the method in the above embodiment when executed by a processor.

[0119] Obviously, those skilled in the art should understand that the modules or steps of the above-mentioned embodiments of the present application can be implemented by general-purpose computer devices, they can be concentrated on a single computer device, or distributed on a network composed of multiple computer devices, optionally, they can be implemented by executable program codes of computer devices, so that they can be stored in a storage device and executed by the computer device, and in some cases, the steps shown or described can be executed in a different order from that herein, or they can be made into individual integrated circuit modules, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. In this way, the embodiments of the present application are not limited to any specific combination of hardware and software.

[0120] It should be noted that the above are only preferred embodiments of the present application, and the patent protection scope of the present application is not limited thereto. Any equivalent structure or equivalent process transformation made using the contents of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A zero-force control method for a photovoltaic support, characterized in that: The photovoltaic support is provided with a joint shaft, and the joint shaft is used to adjust the posture of the photovoltaic assembly. The zero-force control method includes: Obtaining the velocity and gravity torque of the joint axis; Determining the friction torque of the joint axis based on the velocity of the joint axis and a pre-trained friction model; Determining a compensation torque according to the friction torque and the gravity torque; The motor is controlled to output the compensation torque to adjust the output torque of the joint shaft.

2. The method according to claim 1, characterized in that The photovoltaic support further includes a force sensor, and the force sensor is connected to the photovoltaic assembly; obtaining the gravity moment of the joint axis includes: Acquiring an initial gravity moment through the force sensor; The initial gravity moment is filtered to obtain the gravity moment.

3. The method according to claim 1, characterized in that Obtaining the gravity moment of the joint axis includes: Obtaining the weight of the photovoltaic assembly and the angle of the joint axis; Determining a state of the photovoltaic assembly according to the angle of the joint axis, wherein the state includes a tilted state or a horizontal state; When the photovoltaic assembly is in a tilted state, determining the gravity moment according to the weight of the photovoltaic assembly and the angle of the joint axis; When the photovoltaic assembly is in a horizontal state, the gravity moment is determined according to the weight of the photovoltaic assembly.

4. The method according to claim 1, characterized in that: The friction model is obtained by the following operations: Determine a test angle interval and a test speed interval, wherein the test angle interval includes a plurality of test angles, and the test speed interval includes a plurality of test speeds; For each test speed, the following operations are performed: in the test angle interval, the joint axis is controlled to move in a clockwise direction and a counterclockwise direction respectively according to the current test speed; during the clockwise movement, the first output torque of the joint axis at each test angle is obtained; During the counterclockwise movement, obtaining a second output torque of the joint axis at each test angle; Determine the friction torque corresponding to the current test speed according to the first output torque and the second output torque corresponding to each of the multiple test angles; Model training is performed based on the friction torques corresponding to the multiple test speeds to obtain the friction model.

5. The method according to claim 4, characterized in that Determining the friction torque corresponding to the current test speed according to the first output torque and the second output torque corresponding to each of the plurality of test angles includes: Obtain the difference between the first output torque and the second output torque at each test angle; Determining the friction torque at each test angle according to the difference; Determining an average friction torque based on the friction torques corresponding to the multiple test angles; The average friction torque is determined as the friction torque corresponding to the current test speed.

6. The method according to claim 1, characterized in that The friction model is obtained by the following operations: Determine a test angle interval and a test speed interval, wherein the test angle interval includes a plurality of test angles, and the test speed interval includes a plurality of test speeds; In the test angle interval, the joint axis is controlled to gradually increase from a minimum test speed to a maximum test speed to move in a clockwise direction, and the joint axis is controlled to gradually decrease from a maximum test speed to a minimum test speed to move in a counterclockwise direction, and the test speed corresponding to each test angle in the clockwise movement and the counterclockwise movement is equal; During the clockwise movement, obtaining a first output torque of the joint axis at each test angle; During the counterclockwise movement, obtaining a second output torque of the joint axis at each test angle; Determine the friction torque of the test speed corresponding to the test angle based on the first output torque and the second output torque of each test angle; Model training is performed based on the friction torques of the multiple test speeds to obtain the friction model.

7. The method according to any one of claims 1 to 6, characterized in that: Determining a compensation torque according to the friction torque and the gravity torque includes: Obtaining the angular acceleration and inertia matrix of the joint axis; Determining the inertia moment of the joint axis according to the angular acceleration and the inertia matrix of the joint axis; The compensation torque is determined according to the inertia torque, the friction torque and the gravity torque.

8. The method according to claim 7, characterized in that Determining a compensation torque according to the friction torque and the gravity torque includes: Determining centrifugal force and Coriolis force torque based on the speed of the joint axis; The compensation torque is determined based on the centrifugal force and Coriolis force term torque, the friction torque and the gravity torque.

9. The method according to claim 8, characterized in that Determining a compensation torque according to the friction torque and the gravity torque includes: The compensation torque is determined based on the inertia torque, the centrifugal force and Coriolis force torque, the friction torque and the gravity torque.

10. A zero-force control device for a photovoltaic support, characterized in that: The photovoltaic support is provided with a joint shaft, and the joint shaft is used to adjust the posture of the photovoltaic assembly. The device includes: An acquisition module, used for acquiring the velocity and gravity torque of the joint axis; A first determination module, configured to determine the friction torque of the joint axis based on the speed of the joint axis and a pre-trained friction model; A second determination module, configured to determine a compensation torque according to the friction torque and the gravity torque; The control module is used to control the motor to output the compensation torque to adjust the output torque of the joint shaft.

11. A computer device, characterized in that: include: at least one processor; and a memory communicatively connected to the at least one processor; wherein: The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method according to any one of claims 1 to 9.

12. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and when the computer instructions are executed by a processor, the method according to any one of claims 1 to 9 is implemented.

13. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to claims 1 to 9 are implemented.

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