Farmland operation method based on inverted pendulum switching control and balance car

Abstract

The invention discloses a farmland operation method based on inverted pendulum switching control and a balance car. The balance car is mainly composed of a car body, a moment balance motor, a pesticide spraying mechanism, a universal rotating wheel mechanism, a hollow rotating platform and a rotating table. The universal rotating wheel mechanism comprises a wheel fork, a wheel direct-current brushless motor and a wheel; the pesticide spraying mechanism comprises a nozzle, a rotating shaft and a pesticide liquid input port; the rotary table, the universal wheel mechanism and the pesticide spraying mechanism are connected to constrain simultaneous rotation of the three mechanisms. Through the driving of a moment balance motor and a wheel direct current brushless motor, the amplitude change of variables 1 and 2 and a weight value a is defined, two inverted pendulum model controllers are switched, and a control system maintains the balance of a vehicle body, and carries out basic reversing balance, flexible turning in a narrow area and a variable-spacing farmland inter-row operation strategy. Therefore, adjustability of the advancing direction and the line spacing range of the inspection vehicle is guaranteed, the problem of vehicle body direction adjustment in a complex environment in the operation process is solved, and precise operation of field targets is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of agricultural field management equipment, and in particular to a farmland operation method and a balancing vehicle based on inverted pendulum switching control. Background Art

[0002] Field management refers to the general term for various management measures carried out during the entire cultivation process from crop sowing to harvesting in the field production process, aiming to create good conditions for the growth and development of crops. These management measures include suppression, thinning, intertillage and weeding, soiling, vine pressing, pruning, topdressing, spraying, drainage, frost and freeze prevention, and pest and disease control. Field management needs to take targeted measures according to the natural conditions of each region and the characteristics of crop growth and development in order to achieve twice the result with half the effort.

[0003] The multifunctional balance vehicle is an intelligent device that combines balance vehicle technology with agricultural field management equipment. It integrates many advantages of balance vehicles, such as fast speed, strong flexibility, safety and reliability. At the same time, it is also programmable and can be programmed according to different environments to complete a variety of field operations, thereby greatly improving operation efficiency and quality.

[0004] At present, the application of two-wheeled smart vehicles has gradually evolved from the traditional "teaching-reproducing" working mode to a new offline programming mode, and has been widely used in agriculture. These devices can efficiently complete operations according to the specified operation trajectory without human intervention.

[0005] However, most current agricultural field management still has the following problems: 1. Most field management is highly dependent on manual labor, with high labor and time costs.

[0006] 2. Mechanized equipment has difficulty moving in narrow terrain. These factors seriously restrict the promotion and application of agricultural field management measures.

[0007] Therefore, there is an urgent need to design a multifunctional balancing vehicle that can flexibly operate between farmland rows to solve the above-mentioned problems in the prior art. Summary of the invention

[0008] The technical problem solved by the present invention is to provide a farmland operation method and a balance vehicle based on inverted pendulum switching control in response to the defects existing in the above-mentioned prior art, so as to solve the problems raised in the above-mentioned background technology that field management is highly dependent on manual labor and mechanized equipment is difficult to move in narrow terrain.

[0009] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: A farmland operation method based on inverted pendulum switching control comprises the following steps: Step P1: According to the physical characteristics of the multifunctional work platform, it is equivalent to two inverted pendulum systems, the body is equivalent to the pendulum rod of the inverted pendulum, and a controlled Lagrangian model is established to obtain the dynamic equations of the two inverted pendulum systems; Step P2: Based on the dynamic equation, two PID controllers of the swing angles of the swing rods of the two inverted pendulum systems are designed, and controller parameters are determined; Step P3: For the two PID controllers of the swing angle, switching between the two controllers is performed according to the difference between the sum of the two wheel angles and the weight value a.

[0010] As a further solution of the present invention, the controller switching method in step P3 includes: Define the switching variables between the two controller modes, the switching variables are the angles between the two wheel end faces and the cross section of the vehicle body, which are ϕ1 and ϕ2 respectively; set the weight value to be a, let a = |(ϕ1 + ϕ2) - 90°|, ranging from 0° to 90°; the initial state of the working platform is that the two wheel end faces are parallel to the cross section of the vehicle body, turn on the main switch of the multifunctional working platform, and the controller switching method includes: In the initial state, the end faces of the two wheels are parallel to the cross section of the vehicle body, and are in the controller-controlled balance of the first inverted pendulum system; when it is necessary to switch the controller, the two wheels are driven to rotate relative to their respective hollow rotating platforms through the turntable to change the angles of φ1 and φ2. When φ1 is greater than or equal to 45° and φ2 is greater than or equal to 45°, as the a value gradually increases, the weights of the input parameters of the two PID controllers are gradually changed, so that the control input of the first inverted pendulum system gradually decreases, and the control input of the second inverted pendulum system gradually increases, until φ1 and φ2 reach 90°, and then the controller is completely converted to the second inverted pendulum system; After the above steps, the two wheels rotate to the state where the end faces are collinear, and are now in the control state of the controller of the second inverted pendulum system; subsequently, when the system needs to switch the controller again, the turntable drives the two wheels to rotate relative to the hollow rotating platform again, changing the angles of φ1 and φ2. When the two wheels rotate to a state where φ1 is less than 45° and φ2 is less than 45°, as the a value gradually increases, the weights of the input parameters of the two PID controllers are changed, so that the control input of the second inverted pendulum system gradually decreases, and the control input of the first inverted pendulum system gradually increases, until φ1 and φ2 are both 0°, and then it is completely converted to the controller of the first inverted pendulum system.

[0011] A farmland operation balancing vehicle based on inverted pendulum switching control includes a vehicle body, a torque balancing motor, a universal wheel mechanism, a hollow rotating platform, a spraying mechanism, a medicine storage box, a battery, and an inclination sensor; wherein: A torque balancing motor is fixedly installed at the center of mass of the vehicle body. The torque balancing motor is fixedly connected to the balancing pendulum. The balancing pendulum is rotated by outputting torque, thereby controlling the posture of the vehicle body. Two hollow rotating platforms are fixedly connected to the two sides of the outer bottom surface of the vehicle body, and each hollow rotating platform includes a turntable, and the lower end surface of the turntable is fixedly connected to the upper surface of the disk below the rotating shaft; The lower end surface of the rotating shaft is fixedly connected to the upper end surface of the wheel fork in the universal wheel mechanism, the universal wheel mechanism is composed of a wheel fork, a wheel and a wheel DC brushless motor, and the wheel DC brushless motor rotor is fixedly connected to the wheel hub; The spraying mechanism includes a liquid medicine input port opened in the upper middle of the rotating shaft, a nozzle fixedly connected to the top of the rotating shaft, and a liquid medicine input port connected to the discharge port of the medicine storage box through a hose. The medicine storage box is symmetrically fixed between the protective shaft sleeves inside the vehicle body and is equipped with a liquid extraction pump inside. The battery is symmetrically fixed to the bottom surface of the vehicle body.

[0012] As a further solution of the present invention, an inclination sensor is fixedly installed on the top of the vehicle body to detect the inclination change of the vehicle body and output an angle change signal to the torque balancing motor, thereby realizing real-time balancing control of the balancing pendulum and the wheel drive system through a PID control algorithm.

[0013] As a further solution of the present invention, the control system of the balancing vehicle includes a first inverted pendulum system and a second inverted pendulum system: The first inverted pendulum system includes a body, a torque balancing motor and a balancing pendulum, and its dynamic equation is established through a controlled Lagrangian model; The second inverted pendulum system includes a body, wheels and wheel brushless DC motors, and its dynamic equations are also established through a controlled Lagrangian model.

[0014] As a further solution of the present invention, the control system includes two PID controllers, which are designed for system 1 and system 2 respectively. The PID controllers are switched by monitoring the angles ϕ1 and ϕ2 between the end faces of the two wheels and the cross-section of the vehicle body, and switching according to a set weight value a = |(ϕ1 + ϕ2) - 90°|.

[0015] As a further solution of the present invention, in the initial state, the end faces of the two wheels of the control system are parallel to the cross-section of the vehicle body. When φ1 ≥ 45° and φ2 ≥ 45°, the input parameter weights of the two PID controllers are adjusted by gradually increasing the weight value a to complete the controller switching from system 2 to system 1 until φ1 and φ2 reach 90°.

[0016] As a further solution of the present invention, when the system needs to switch back from system 1 to system 2, the control input of system 1 is gradually reduced and the control input of system 2 is increased by adjusting the angles of φ1 and φ2 to φ1<45° and φ2<45°, until both φ1 and φ2 are 0°, and the controller switching is completed.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. Innovative design of self-balancing control system: The present invention adopts a double inverted pendulum system and combines it with a PID control algorithm to achieve automatic switching and precise control of the self-balancing vehicle under different operating conditions. By introducing the linkage design of the torque balancing motor and the balancing pendulum, it can effectively cope with the inclination and instability of complex field terrain, realize dynamic posture adjustment of the vehicle body, and improve the stability and flexibility of the self-balancing vehicle in narrow and irregular working environments. Compared with traditional self-balancing vehicles, the present invention greatly improves the balance and anti-overturning ability of the working platform.

[0018] 2. Intelligent controller switching mechanism: The present invention achieves seamless switching between the two inverted pendulum systems by defining the controller switching variables (ϕ1, ϕ2) and their relationship with the weight value a. This innovative control method enables the self-balancing vehicle to adjust autonomously according to environmental changes during operation, ensuring that the posture of the vehicle body always remains in the optimal state, avoiding the problems of multiple human interventions and complex switching processes in traditional operating equipment. This intelligent controller switching mechanism is the first of its kind in the prior art, which significantly improves the automation level and operating efficiency of the self-balancing vehicle.

[0019] 3. Modular structural design improves operational adaptability: The present invention organically combines multiple functional modules such as the vehicle body, torque balancing motor, hollow rotating platform, universal wheel mechanism, and spraying mechanism. Through precise structural layout and mutual coordination, it can achieve dynamic adjustment of the operating direction, row spacing, and steering to meet the needs of different farmland environments. In particular, the linkage design of the spraying mechanism and the universal wheel mechanism ensures that the operating direction of the spray head is always perpendicular to the wheel end face, ensuring the accuracy and consistency of spraying and inspection operations, and greatly improving the quality of operations.

[0020] 4. Wide adaptability to the operating range and environment: Through the unique row spacing adjustment mechanism, the present invention can automatically adjust the wheel speed and direction according to the change of crop row spacing, so that the nozzle spacing changes in real time. This technology breaks through the limitations of traditional equipment operating under fixed row spacing, and can flexibly respond to the needs of different planting patterns, especially in the case of irregular crop growth or inconsistent row spacing, it can still ensure efficient and accurate operation results, truly realizing one vehicle with multiple uses and one machine with multiple functions.

[0021] 5. Reduce manual intervention and improve work efficiency: The balance vehicle of the present invention greatly reduces the dependence on manual operation through intelligent control and automated operation, reducing labor intensity and operating costs. At the same time, the equipment can independently complete tasks according to the preset path and working mode, which not only improves the mechanization degree of field management, but also reduces the errors and uncertainties caused by manual management, ensuring the standardization and efficiency of operations.

[0022] 6. Improve the intelligent level of field management: Compared with the existing technology, the present invention integrates the intelligent control, flexible steering, dynamic adjustment and other functions of the balance vehicle, which fully reflects the development direction of intelligent agricultural equipment. Its unique inverted pendulum control switching technology provides a novel and efficient solution for field operation equipment.

[0023] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0025] Figure 1 It is a three-dimensional structural diagram of the multifunctional field management inspection vehicle of the invention.

[0026] Figure 2 It is the front view of the multifunctional inspection vehicle for field management of the invention.

[0027] Figure 3 It is a cross-sectional view at AA of the multifunctional field management inspection vehicle of the invention.

[0028] In the figure: 1. balancing pendulum; 2. torque balancing motor; 3. vehicle body; 4. nozzle; 5. rotating shaft; 6. liquid medicine input port; 7. protective bushing; 8. medicine storage box; 9. hollow rotating platform; 10. turntable; 11. wheel fork; 12. wheel; 13. wheel DC brushless motor; 14. battery; 15. tilt sensor; 16. liquid pump. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] See also Figure 1 —3. In an embodiment of the present invention, a farmland operation method based on inverted pendulum switching control comprises the following steps: Step P1: According to the physical characteristics of the multifunctional work platform, it is equivalent to two inverted pendulum systems, the body is equivalent to the pendulum rod of the inverted pendulum, and a controlled Lagrangian model is established to obtain the dynamic equations of the two inverted pendulum systems; Step P2: Based on the dynamic equation, two PID controllers of the swing angles of the swing rods of the two inverted pendulum systems are designed, and controller parameters are determined; Step P3: For the two PID controllers of the swing angle, switching between the two controllers is performed according to the difference between the sum of the two wheel angles and the weight value a.

[0031] As a further solution of the present invention, the controller switching method in step P3 includes: Define the switching variables between the two controller modes, the switching variables are the angles between the two wheel end faces and the cross section of the vehicle body, which are ϕ1 and ϕ2 respectively; set the weight value to be a, let a = |(ϕ1 + ϕ2) - 90°|, ranging from 0° to 90°; the initial state of the working platform is that the two wheel end faces are parallel to the cross section of the vehicle body, turn on the main switch of the multifunctional working platform, and the controller switching method includes: In the initial state, the end faces of the two wheels are parallel to the cross section of the vehicle body, and are in the controller-controlled balance of the first inverted pendulum system; when it is necessary to switch the controller, the two wheels are driven to rotate relative to their respective hollow rotating platforms through the turntable to change the angles of φ1 and φ2. When φ1 is greater than or equal to 45° and φ2 is greater than or equal to 45°, as the a value gradually increases, the weights of the input parameters of the two PID controllers are gradually changed, so that the control input of the first inverted pendulum system gradually decreases, and the control input of the second inverted pendulum system gradually increases, until φ1 and φ2 reach 90°, and then the controller is completely converted to the second inverted pendulum system; After the above steps, the two wheels rotate to the state where the end faces are collinear, and are now in the control state of the controller of the second inverted pendulum system; subsequently, when the system needs to switch the controller again, the turntable drives the two wheels to rotate relative to the hollow rotating platform again, changing the angles of φ1 and φ2. When the two wheels rotate to a state where φ1 is less than 45° and φ2 is less than 45°, as the a value gradually increases, the weights of the input parameters of the two PID controllers are changed, so that the control input of the second inverted pendulum system gradually decreases, and the control input of the first inverted pendulum system gradually increases, until φ1 and φ2 are both 0°, and then it is completely converted to the controller of the first inverted pendulum system.

[0032] The present invention is a multifunctional inspection vehicle for field management. It is composed of a vehicle body 3, a torque balancing motor 2, a hollow rotating platform 9, a spraying mechanism, a universal wheel mechanism, a medicine storage box 8, a battery 14, and an inclination sensor 15. The universal wheel mechanism is composed of a wheel fork 11, a wheel 12, and a wheel DC brushless motor 13; the spraying mechanism includes a rotating shaft 5, a liquid medicine input port 6 opened in the upper part of the rotating shaft 5, and a spray head 4 fixedly connected to the upper end of the rotating shaft 5.

[0033] First, a balancing pendulum 1 is fixedly installed at the center of mass of the vehicle body and driven by a fixed torque balancing motor 2. An inclination sensor 15 is fixedly installed in the middle of the outer side of the vehicle body, and two protective sleeves 7 are symmetrically fixedly connected inside the vehicle body 3. The protective sleeve 7 contains a rotating shaft 5 for the working platform; and two hollow rotating platforms 9 are fixedly connected at the concentric fit of the protective sleeve 7 on both sides of the outer bottom surface of the vehicle body 2. Each hollow rotating platform 9 includes a respective turntable 10; the lower end surface of the turntable 10 is fixedly connected to the upper surface of the disc below the rotating shaft 5. Then, the lower end surface of the rotating shaft 5 is fixedly connected to the upper end surface of the wheel fork 11 of the universal wheel mechanism; in the universal wheel mechanism, the wheel 12 is fixedly connected to the rotor of the wheel DC brushless motor 13 at the wheel hub. Then, in the sprinkler mechanism, a liquid medicine input port 6 is opened at the part of the rotating shaft 5 that is not protected by the protective sleeve 7; the liquid medicine input port 6 and the discharge port of the medicine storage box 8 can be connected by a hose or other liquid transmission element. The medicine storage boxes 8 are symmetrically fixed between the protective sleeves 7 inside the vehicle body 3, and a liquid pump 15 is fixed inside the two medicine storage boxes 8; two batteries 14 are placed between the medicine storage boxes 8. The batteries 14 are symmetrically fixed to the bottom surface of the vehicle body 3. Further, when the hollow rotating platform 9 is connected with the rotating shaft 5 and the universal wheel mechanism, it is necessary to ensure that the operating direction of the sprinkler 4 above the rotating shaft 5 is always perpendicular to the end face of the wheel 12, so that the operating direction of the multifunctional working platform is always vertically outward along the forward direction, completing the precise operation of the target object in the field.

[0034] The main components include a torque balancing motor 2 fixed at the center of mass of the vehicle body 3. The balance of the vehicle is maintained by combining a balancing pendulum 11 system driven by the torque balancing motor 2 and an inverted pendulum system driven by two DC brushless motors of the wheels 12 to maintain the balance of the vehicle. Two controllers and a controller switching method are built through a PID control algorithm to enable the multifunctional working platform to maintain balance in different postures. The technical features of the present invention include the following steps: Step P1, according to the physical characteristics of the multifunctional work platform, it is equivalent to two inverted pendulum systems, the body 3 is equivalent to the pendulum of the inverted pendulum, and a controlled Lagrangian model is established to obtain the dynamic equations of the two inverted pendulum systems: Step P2, based on the dynamic equations, two PID controllers of the swing angle are designed for the swing angles of the pendulums of the two inverted pendulum systems, and the controller parameters are determined; Step P3, for the two PID controllers of the swing angle, switching between the controllers is performed according to the swing angle range or the posture requirements of the multifunctional platform.

[0035] In the method for constructing and switching a self-balancing controller of a farmland operation balancing vehicle based on inverted pendulum switching control, step P1 includes: establishing the multifunctional operation platform as the two inverted pendulum systems: System 1: comprises a vehicle body 3, a torque balancing motor 2 arranged at the center of mass of the vehicle body 3, and a balancing pendulum 1 driven by the torque balancing motor 2; System 2: includes a vehicle body 3, a DC brushless motor for a wheel 12 disposed at the bottom of the vehicle body 3, and a wheel 12 driven by the DC brushless motor for the wheel 12; Calculate the kinetic energy and potential energy of the two inverted pendulum systems respectively; obtain the Lagrangian of the two inverted pendulum systems based on the kinetic energy and the potential energy; establish a mechanical model of the two controlled inverted pendulum systems according to the Euler-Lagrange equation; obtain the motion equations of the two controlled inverted pendulum systems based on the Lagrangian and the mechanical model; simplify and organize the two motion equations to obtain expressions for the swing angle of the pendulum rod, the swing angular acceleration, the driving torque of the balancing pendulum 1, and the horizontal acceleration of the working platform.

[0036] After the balance controller is constructed, two hollow rotating platforms 9 are connected to the rotating shaft 5 and the universal wheel mechanism under the vehicle body 3 to ensure that the wheels 12 of the universal wheel mechanism and the nozzles 4 in the spraying mechanism rotate simultaneously. The working direction of the nozzles 4 is always perpendicular to the wheels 12. The uninterrupted liquid delivery through the liquid storage tank and the liquid input port 6 of the rotating shaft 5 can keep the inspection vehicle continuously spraying on both sides of the moving direction. The battery provides power output to complete the precise operation of the target in the field.

[0037] A multifunctional balance vehicle that can realize direction-changing turns in narrow areas and adjustable working range. It can perform field inspections at different intervals according to the working environment, spraying operations and other field management tasks, as well as flexible changes in posture when the working environment is narrow: First, the balance PID controller and posture transformation are mainly divided into two situations: First, define the switching variables between the two modes. The switching variables are defined as the rotation angles between the end faces of the two wheels and the cross section of the vehicle body, which are φ1 and φ2 respectively: a= |φ1+φ2-90| °(0°≦a≦90°). Secondly, make sure that the end faces of the two wheels of the working platform are parallel to the cross section of the vehicle body. Then, turn on the main switch of the multifunctional working balance vehicle: ①: At this time, the end faces of both wheels are parallel to the cross section of the vehicle body, and the vehicle body is controlled to balance and move forward under the controller of the inverted pendulum system 2. When the controller needs to be switched, the wheel fork first drives the two wheels to rotate relative to the turntable. When φ1+φ2 ≧90°, the weights of the input parameters of the two PID controllers are changed in direct proportion by the value of a, until φ1 and φ2 are both 90°, and the vehicle body is completely switched to the inverted pendulum system 1 controller to balance the vehicle body. ②: After ①, the vehicle body is in the state that the two wheels have rotated to the end face collinear state. When the controller needs to be switched, the wheel fork first drives the two wheels to rotate relative to the turntable. When the two wheels rotate to φ1+φ2<90°, the weights of the two PID controller input parameters are changed by the value of a, which is proportional, until φ1 and φ2 are both 0°, and it is completely converted to the inverted pendulum system 2 controller to balance the vehicle body. It can realize the flexible steering of the multifunctional working balance vehicle and solve the problem of adjusting the vehicle body in 3 directions in complex environments during operation.

[0038] Second, there are two specific field operation row spacing change strategies, as follows: ①: When the self-balancing vehicle is moving forward, it is found that the crops on the left side are moving forward regularly, and the row spacing of the crops on the right side is getting smaller.

[0039] It should be that on the side where the crop row spacing remains unchanged, the wheel 12 continues to move forward at a constant speed; on the side where the crop row spacing becomes narrower, the wheel 12 accelerates forward to reduce the working distance between the two nozzles 4. During the period of time when the wheel 12 is accelerated, the turntable 10 at one end of the constant-speed wheel 12 should make the wheel 12 swing inward, and the turntable 10 at one end of the accelerated wheel 12 should make the wheel 12 swing outward until the target row spacing is reached and the pitch change is completed.

[0040] ②: When the working platform has not reached the maximum working row spacing, when the balance vehicle is moving forward, it is found that the crops on the left side are moving forward regularly and the row spacing of crops on the right side is widening.

[0041] It should be that on the side where the crop row spacing remains unchanged, the wheel 12 continues to move forward at a constant speed; on the side where the crop row spacing becomes wider, the wheel 12 slows down and moves backward, so that the working distance between the two nozzles 4 becomes larger. During the period of time when the designated wheel 12 slows down, the turntable 10 at one end of the constant-speed wheel 12 should make the wheel 12 swing outward, and the turntable 10 at one end of the accelerated wheel 12 should make the wheel 12 swing inward until the target row spacing is reached and the pitch change is completed. Example

[0042] The present embodiment provides a multifunctional farmland operation balancing vehicle based on inverted pendulum control switching, and aims to describe in detail the connection relationship, positional relationship and working principle of its structure so that ordinary technicians in this field can accurately implement it.

[0043] The balancing vehicle mainly includes a body 3, a torque balancing motor 2, a universal wheel mechanism, a hollow rotating platform 9, a medicine spraying mechanism, a medicine storage box 8, a battery 14, a tilt sensor 15 and other components. Its structural design and functional coordination are as follows: 1. Body and balance control module: The body 3 is the main part of the balance vehicle. A torque balance motor 2 is fixedly installed at the center of mass. The torque balance motor 2 controls the posture of the body 3 by driving the balance pendulum 1 fixedly connected thereto. The torque balance motor 2 outputs a control torque to rotate the balance pendulum 1, thereby adjusting the center of gravity and posture of the body 3. The inclination sensor 15 is fixedly installed on the top of the body 3, and is used to detect the change in the inclination angle of the body in real time, and transmit the signal to the torque balance motor 2. Based on the data output by the sensor, the torque balance motor 2 adjusts the posture of the balance pendulum 1 through the PID control algorithm, thereby achieving stable control of the balance vehicle under different operating conditions.

[0044] 2. Hollow rotating platform and rotating structure: Two hollow rotating platforms 9 are fixedly connected to the outer bottom surface of the vehicle body 3 on both sides, and a turntable 10 is arranged inside each hollow rotating platform 9, and the lower end surface of the turntable 10 is fixedly connected to the upper surface of the lower disc of the rotating shaft 5. The combined design of the hollow rotating platform 9 and the turntable 10 allows the turntable 10 to rotate coaxially, thereby adjusting the connection angle with the rotating shaft 5 to meet different operation requirements.

[0045] 3. Universal wheel mechanism: The lower end face of the rotating shaft 5 is fixedly connected to the upper end face of the wheel fork 11 in the universal wheel mechanism. The universal wheel mechanism is composed of the wheel fork 11, the wheel 12 and the wheel DC brushless motor 13. The rotor of the wheel DC brushless motor 13 is fixedly connected to the hub of the wheel 12. The speed and direction of the wheel 12 are controlled by the drive of the brushless motor 13. The universal wheel mechanism can move flexibly in all directions, so that the balancing vehicle can be freely turned and adjusted in a narrow area.

[0046] 4. Spraying mechanism and liquid medicine delivery system: The spraying mechanism consists of a rotating shaft 5, a liquid medicine input port 6 located in the middle and upper part of the rotating shaft, and a nozzle 4 fixedly connected to the top of the rotating shaft. The liquid medicine input port 6 is connected to the discharge port of the medicine storage box 8 through a hose to achieve continuous supply of liquid medicine. The medicine storage box 8 is symmetrically fixed between the protective sleeves 7 inside the vehicle body 3. A liquid pump 16 is installed inside the medicine storage box 8, and the liquid medicine is transported from the medicine storage box 8 to the nozzle 4 through the liquid pump 16. During the operation, the nozzle 4 always remains perpendicular to the end face of the wheel 12 to ensure the accuracy of the spraying direction, thereby improving the accuracy and efficiency of the operation.

[0047] 5. Power and electricity supply: Batteries 14 are symmetrically placed on both sides of the medicine storage box 8. The batteries 14 are the power supply source for the entire balancing vehicle. The batteries 14 are symmetrically fixed to the inner bottom surface of the vehicle body 3 to provide continuous power output for all electrical components such as the torque balancing motor 2, the wheel DC brushless motor 13, and the liquid pump 16.

[0048] 6. Double inverted pendulum control system: The control system of the self-balancing vehicle achieves stable operation based on the switching control of two inverted pendulum systems. System 1 includes a vehicle body 3, a torque balancing motor 2 and a balancing pendulum 1, which is mainly used for the balance control of the vehicle body posture; system 2 includes a vehicle body 3, wheels 12 and a wheel DC brushless motor 13, which is responsible for the horizontal drive and direction control of the vehicle body. The two systems respectively establish their dynamic equations through controlled Lagrangian models. When changes in the operating environment are detected, seamless switching between controllers is used to ensure that the self-balancing vehicle is always in a stable working state.

[0049] 7. Intelligent controller switching and balance adjustment: The controller switching process is adjusted by the two angle parameters φ1 and φ2 and the weight value a. When the self-balancing vehicle needs to switch from system 2 to system 1, adjust φ1 and φ2 to 90° and switch the controller to achieve body posture balance; conversely, when it is necessary to switch back from system 1 to system 2, adjust the angles of φ1 and φ2 to 0° and switch to the horizontal drive mode to ensure smooth switching and effective operation of the self-balancing vehicle in different operating states.

[0050] Through the above structural design and the coordinated cooperation of various components, the multifunctional farmland balance vehicle of this embodiment can perform flexible and efficient operations in a variety of complex field environments. Its balance control and intelligent switching mechanism ensure the stability and adaptability of the equipment, providing a new solution for precision agricultural management.

[0051] In the present invention, unless otherwise clearly stipulated and limited, the terms "installation", "setting", "connection", "fixation", "screw-on" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0052] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

Claims

1. A farmland operation method based on inverted pendulum switching control, characterized in that: The following steps are involved: Step P1: According to the physical characteristics of the multifunctional work platform, it is equivalent to two inverted pendulum systems, the body is equivalent to the pendulum rod of the inverted pendulum, and a controlled Lagrangian model is established to obtain the dynamic equations of the two inverted pendulum systems; Step P2: Based on the dynamic equation, two PID controllers of the swing angles of the swing rods of the two inverted pendulum systems are designed, and controller parameters are determined; Step P3: For the two PID controllers of the swing angle, switching between the two controllers is performed according to the difference between the sum of the two wheel angles and the weight value a.

2. A farmland operation method based on inverted pendulum switching control according to claim 1, characterized in that: The controller switching method in step P3 includes: Define the switching variables between the two controller modes, the switching variables are the angles between the two wheel end faces and the cross section of the vehicle body, which are ϕ1 and ϕ2 respectively; set the weight value to be a, let a = |(ϕ1 + ϕ2) - 90°|, ranging from 0° to 90°; the initial state of the working platform is that the two wheel end faces are parallel to the cross section of the vehicle body, turn on the main switch of the multifunctional working platform, and the controller switching method includes: In the initial state, the end faces of the two wheels are parallel to the cross section of the vehicle body, and are in the controller-controlled balance of the first inverted pendulum system; when it is necessary to switch the controller, the two wheels are driven to rotate relative to their respective hollow rotating platforms through the turntable to change the angles of φ1 and φ2. When φ1 is greater than or equal to 45° and φ2 is greater than or equal to 45°, as the a value gradually increases, the weights of the input parameters of the two PID controllers are gradually changed, so that the control input of the first inverted pendulum system gradually decreases, and the control input of the second inverted pendulum system gradually increases, until φ1 and φ2 reach 90°, and then the controller is completely converted to the second inverted pendulum system; After the above steps, the two wheels rotate to the state where the end faces are collinear, and are now in the control state of the controller of the second inverted pendulum system; subsequently, when the system needs to switch the controller again, the turntable drives the two wheels to rotate relative to the hollow rotating platform again, changing the angles of φ1 and φ2. When the two wheels rotate to a state where φ1 is less than 45° and φ2 is less than 45°, as the a value gradually increases, the weights of the input parameters of the two PID controllers are changed, so that the control input of the second inverted pendulum system gradually decreases, and the control input of the first inverted pendulum system gradually increases, until φ1 and φ2 are both 0°, and then it is completely converted to the controller of the first inverted pendulum system.

3. A farmland operation balancing vehicle based on inverted pendulum switching control, comprising a vehicle body, a torque balancing motor, a universal wheel mechanism, a hollow rotating platform, a spraying mechanism, a medicine storage box, a battery, and an inclination sensor; wherein: A torque balancing motor is fixedly installed at the center of mass of the vehicle body. The torque balancing motor is fixedly connected to the balancing pendulum. The balancing pendulum is rotated by outputting torque, thereby controlling the posture of the vehicle body. Two hollow rotating platforms are fixedly connected to the two sides of the outer bottom surface of the vehicle body, and each hollow rotating platform includes a turntable, and the lower end surface of the turntable is fixedly connected to the upper surface of the disk below the rotating shaft; The lower end surface of the rotating shaft is fixedly connected to the upper end surface of the wheel fork in the universal wheel mechanism, the universal wheel mechanism is composed of a wheel fork, a wheel and a wheel DC brushless motor, and the wheel DC brushless motor rotor is fixedly connected to the wheel hub; The spraying mechanism includes a liquid medicine input port opened in the upper middle of the rotating shaft, a nozzle fixedly connected to the top of the rotating shaft, and a liquid medicine input port connected to the discharge port of the medicine storage box through a hose. The medicine storage box is symmetrically fixed between the protective shaft sleeves inside the vehicle body and is equipped with a liquid extraction pump inside. The battery is symmetrically fixed to the bottom surface of the vehicle body.

4. The farmland operation balancing vehicle based on inverted pendulum switching control according to claim 3, characterized in that: The inclination sensor is fixedly installed on the top of the vehicle body to detect the inclination change of the vehicle body and output the angle change signal to the torque balancing motor, realizing real-time balancing control of the balancing pendulum and the wheel drive system through the PID control algorithm.

5. The farmland operation balancing vehicle based on inverted pendulum switching control according to claim 4, characterized in that: The control system of the balancing vehicle includes a first inverted pendulum system and a second inverted pendulum system: The first inverted pendulum system includes a body, a torque balancing motor and a balancing pendulum, and its dynamic equation is established through a controlled Lagrangian model; The second inverted pendulum system includes a body, wheels and wheel brushless DC motors, and its dynamic equations are also established through a controlled Lagrangian model.

6. The farmland operation balancing vehicle based on inverted pendulum switching control according to claim 5, characterized in that: The control system includes two PID controllers, which are designed for system 1 and system 2 respectively. The PID controllers are switched by monitoring the angles ϕ1 and ϕ2 between the end faces of the two wheels and the cross section of the vehicle body, and switching according to the set weight value a = |(ϕ1 + ϕ2) -90°|.

7. The farmland operation balancing vehicle based on inverted pendulum switching control according to claim 6, characterized in that: In the initial state, the end faces of the two wheels of the control system are parallel to the cross section of the vehicle body. When φ1 ≥ 45° and φ2 ≥ 45°, the input parameter weights of the two PID controllers are adjusted by gradually increasing the weight value a to complete the controller switching from system 2 to system 1 until φ1 and φ2 reach 90°.

8. The farmland operation balancing vehicle based on inverted pendulum switching control according to claim 7, characterized in that: When the system needs to switch back from system 1 to system 2, the control input of system 1 is gradually reduced and the control input of system 2 is increased by adjusting the angles of φ1 and φ2 to φ1 < 45° and φ2 < 45° until both φ1 and φ2 are 0°, completing the controller switching.

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