Agricultural mobile platform and steering control method thereof

Abstract

The invention belongs to the technical field of agricultural machinery, and discloses an agricultural mobile platform and a steering control method thereof.The agricultural mobile platform comprises a vehicle control unit, a steering device and a mobile device, the steering device comprises multiple sets of steering driving parts and steering drivers, and the vehicle control unit is used for receiving a steering instruction and sending a signal to the steering drivers; the steering drivers are used for controlling and driving all the sets of steering driving pieces to keep steering fixed or adjust the steering angle, the moving device comprises a connecting frame, a rotation driving piece, a rotation driver and wheels, and the vehicle control unit is further used for receiving an acceleration or braking instruction to the rotation driver. And the rotary driver is configured to adjust the current frequency and amplitude of each group of steering driving pieces in real time. According to the agricultural mobile platform, the steering device and the mobile device are decoupled, so that each wheel can be independently controlled, the energy efficiency ratio and maneuverability are improved, and the adaptability of the agricultural mobile platform in limited spaces such as greenhouses, orchards and three-dimensional planting is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of agricultural machinery, and in particular to an agricultural mobile platform and a steering control method thereof. Background Art

[0002] With the increase in labor costs and agricultural efficiency demands, the demand for the application of automation and unmanned operations in facility agriculture is becoming increasingly strong. Intelligent unmanned agricultural machinery has gradually become the core development direction of facility agriculture due to its advantages of efficient, precise and safe operations. Whether it is fertilizing, spraying, picking and transportation, etc., the operation links require precise positioning and tracking of mobile platforms.

[0003] Existing agricultural mobile platforms often adopt a relatively fixed front-wheel steering and rear-wheel drive mode, which can meet basic operating needs in relatively open and regular field environments. However, in relatively narrow and complex spaces such as greenhouses and field paths, due to the large turning radius and the limitation of the turning angle, the mobile platform is not flexible enough and it is difficult to accurately reach the location where it needs to be operated or transported, resulting in low operating efficiency and easy damage to surrounding crops or facilities.

[0004] Therefore, it is urgent to design a new agricultural mobile platform and its steering control method to improve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide an agricultural mobile platform and a steering control method thereof, so as to solve the technical problems that the existing agricultural mobile platform is limited by the steering angle, is difficult to move accurately to the specified position, has low operating efficiency, and is easy to cause damage to surrounding crops or facilities.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] The agricultural mobile platform comprises a frame, a power source, a vehicle controller, a steering device and a moving device;

[0008] The steering device comprises a plurality of steering drive components and a steering driver, wherein the rotation axis of the steering drive components is arranged on the vehicle frame along a vertical direction, and the steering driver is communicatively connected with the plurality of steering drive components and the vehicle controller;

[0009] Wherein, the vehicle controller is used to receive the steering command, calculate the target number of steps and the target direction, and send a signal to the steering driver, and the steering driver is used to convert the signal into a winding power-on control and drive each group of the steering drive components to keep the steering fixed or adjust the steering angle;

[0010] The output end of each group of the steering drive members is connected to the mobile device, and the mobile device includes a connecting frame, a rotating drive member, a rotating driver and a wheel. The connecting frame is connected to the output end of the steering drive member, and the rotating axis of the wheel is arranged on the connecting frame along the horizontal direction. The output end of the rotating drive member is connected to the wheel, and the rotating driver is communicatively connected with multiple groups of the rotating drive members and the vehicle controller;

[0011] Among them, the vehicle controller is also used to receive the torque and speed instructions required for calculating the acceleration or braking instructions to the rotation driver, and the rotation driver is configured to adjust the current frequency and amplitude of each group of the steering drive components in real time according to the torque and speed instructions.

[0012] As a preferred solution of the agricultural mobile platform, the steering drive component includes:

[0013] A driving motor, wherein the driving motor is arranged on the frame;

[0014] A reducer, the reducer being arranged at the output end of the driving motor;

[0015] A bearing, a seat ring of the bearing is connected to the frame, a shaft ring of the bearing is connected to the reducer, and the connecting frame is connected to the shaft ring of the bearing.

[0016] As a preferred solution of the agricultural mobile platform, the reducer includes:

[0017] An inner gear ring, the inner gear ring is located in the bearing, and the outer periphery of the inner gear ring is connected to the inner wall of the shaft ring of the bearing;

[0018] A gear is coaxially connected to the output end of the driving motor, and the outer periphery of the gear is meshed with the inner wall of the inner gear ring.

[0019] As a preferred solution of the agricultural mobile platform, the rotating drive member includes a hub motor, the hub motor is connected to the connecting frame, and the output end of the hub motor is connected to the wheel.

[0020] As a preferred solution for the agricultural mobile platform, the power source includes a power battery, and the agricultural mobile platform also includes an inverter. The inverter is arranged on the frame, and the inverter is electrically connected to the power battery for converting direct current into three-phase alternating current required by the hub motor.

[0021] As a preferred solution for the agricultural mobile platform, the connecting frame is arranged in an L shape, and the wheels are located at the right angle inner side of the connecting frame.

[0022] As a preferred solution for the agricultural mobile platform, the steering device and the mobile device are each provided with four groups, and the four groups are respectively arranged at the four corners of the frame.

[0023] As a preferred solution for the agricultural mobile platform, a body cover is provided on the frame, a receiving cavity is formed between the body cover and the frame, and the power supply, the vehicle controller, the steering drive and the rotation drive are located in the receiving cavity.

[0024] The steering control method of the agricultural mobile platform is implemented based on the agricultural mobile platform mentioned above, and the steering control method of the agricultural mobile platform includes the following steps:

[0025] The vehicle controller receives the steering command and sends it to the steering driver;

[0026] The steering driver correspondingly controls each steering drive member to selectively keep the steering fixed or adjust the steering angle;

[0027] The vehicle controller receives the movement command and sends it to the rotation drive;

[0028] The rotary driver controls the rotation of each rotary drive member accordingly.

[0029] As a preferred solution of the steering control method of the agricultural mobile platform, the vehicle controller has at least a front wheel steering mode, an all-wheel same-direction steering mode, and an in-situ steering mode;

[0030] In the front wheel steering mode, the steering drive member located at the front wheel rotates, and the steering drive member located at the rear wheel remains fixed, so that the agricultural mobile platform achieves steering;

[0031] In the all-wheel same-direction steering mode, the steering drive components of the front and rear wheels rotate in the same direction and angle, and the agricultural mobile platform achieves lateral translation;

[0032] In the in-situ steering mode, the steering drive components of the wheels on both sides of the frame rotate in opposite directions respectively, and the agricultural mobile platform rotates in-situ.

[0033] Beneficial effects of the present invention:

[0034] The agricultural mobile platform provided by the present invention integrates the steering device and the mobile device by using a vehicle controller. The vehicle controller receives the steering command and sends a signal to the steering driver, which converts the signal into winding power control and drives each group of steering drive parts to move. The steering angle can be adjusted 360°, is not limited by the steering angle, has high flexibility, and can be accurately moved to the specified position. The vehicle controller receives the acceleration or braking command and sends a signal to the rotation driver, which converts the signal into torque and speed commands to drive each group of rotation drive parts to move, and can adjust the output in real time, achieve efficient and accurate driving and dynamic response, and further improve the mobile accuracy. In summary, by decoupling the steering device and the mobile device, each wheel can be controlled separately, providing multiple controllable degrees of freedom, supporting the adjustment of the wheel angles of multiple wheels, reducing the weight and structural complexity of the agricultural mobile platform, improving the energy efficiency ratio and maneuverability, and thus improving the adaptability in confined spaces such as greenhouses, orchards, and three-dimensional planting.

[0035] The steering control method of the agricultural mobile platform provided by the present invention integrates the steering device and the mobile device together by utilizing the whole vehicle controller, so that each wheel can be controlled individually, provides multiple controllable degrees of freedom, supports adjustment of the wheel angles of multiple wheels, and improves adaptability in confined spaces such as greenhouses, orchards, and three-dimensional plantings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a schematic diagram of the structure of an agricultural mobile platform provided by an embodiment of the present invention;

[0037] Figure 2 It is a structural schematic diagram of a hidden vehicle body cover of an agricultural mobile platform provided by an embodiment of the present invention;

[0038] Figure 3 is a schematic diagram of the structure of a mobile device provided by an embodiment of the present invention;

[0039] Figure 4 is a schematic structural diagram of a steering drive member provided by an embodiment of the present invention;

[0040] Figure 5 It is a whole vehicle layout diagram of the agricultural mobile platform provided by an embodiment of the present invention;

[0041] Figure 6 is a structural schematic diagram of a front wheel steering mode of a steering control method for an agricultural mobile platform provided by an embodiment of the present invention;

[0042] Figure 7 It is a structural schematic diagram of an all-wheel same-direction steering mode of a steering control method for an agricultural mobile platform provided by an embodiment of the present invention;

[0043] Figure 8It is a structural schematic diagram of an in-situ steering mode of a steering control method for an agricultural mobile platform provided in an embodiment of the present invention.

[0044] In the figure:

[0045] 1. Vehicle frame; 11. Vehicle cover;

[0046] 2. Power battery;

[0047] 3. Vehicle controller;

[0048] 4. Steering drive; 41. Driving motor; 42. Speed ​​reducer; 421. Internal gear ring; 422. Gear; 43. Bearing;

[0049] 5. Steering drive;

[0050] 6. Rotating drive member; 61. Wheel hub motor; 62. Inverter;

[0051] 7. Rotate the drive;

[0052] 8. Connecting frame;

[0053] 9. Wheels. DETAILED DESCRIPTION

[0054] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0055] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; 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. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0056] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0057] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0058] Existing agricultural mobile platforms often adopt a relatively fixed front-wheel steering and rear-wheel drive mode, which can meet basic operating needs in relatively open and regular field environments. However, in relatively narrow and complex spaces such as greenhouses and field paths, due to the large turning radius and the limitation of the turning angle, the mobile platform is not flexible enough and it is difficult to accurately reach the location where it needs to be operated or transported, resulting in low operating efficiency and easy damage to surrounding crops or facilities.

[0059] In order to solve the above problems, combined Figure 1-Figure 5 As shown, this embodiment provides an agricultural mobile platform, including a frame 1, the frame 1 is a plate structure, the upper plate mask of the frame 1 is provided with a body cover 11, the body cover 11 is detachably connected to the frame 1 through fasteners, and a receiving cavity is formed between the body cover 11 and the frame 1, and the electronic devices of the agricultural mobile platform are integrated in the receiving cavity. Among them, the body cover 11 is made of corrosion-resistant material, has good strength and stability, and can protect the electronic devices inside the body cover 11.

[0060] Optionally, the fastener is a bolt. The vehicle body cover 11 can be disassembled by installing and removing the bolt, which facilitates the maintenance of the electronic components in the accommodating cavity.

[0061] In addition, the connection between the vehicle body cover 11 and the frame 1 is also equipped with a sealing strip, which is made of rubber material and can prevent water and dust from entering the accommodating cavity, thereby improving the durability and safety of the agricultural mobile platform.

[0062] like Figure 1As shown, a heat dissipation hole is opened on the side of the vehicle body cover 11, and a plurality of heat dissipation holes are provided, and the heat in the vehicle body cover 11 can be dissipated through the heat dissipation holes.

[0063] like Figure 2 As shown, the agricultural mobile platform also includes a power source, a vehicle controller 3, a steering device and a mobile device. The steering device and the mobile device are electrically connected to the power source and the vehicle controller 3. Preferably, the power source is a power battery 2, and the power battery 2 provides a power source for the agricultural mobile platform.

[0064] The steering device of this embodiment includes multiple groups of steering drive members 4 and a steering driver 5. The rotation axis of the steering drive member 4 is arranged on the frame 1 in the vertical direction. The steering driver 5 is connected to the multiple groups of steering drive members 4 and the vehicle controller 3. The multiple groups of steering drive members 4 are independent of each other, and the steering driver 5 controls the multiple groups of steering drive members 4 to rotate separately without interfering with each other. The vehicle controller 3 is used to receive the steering instruction to calculate the target number of steps and the target direction and send a signal to the steering driver 5. The steering driver 5 is used to convert the signal into a winding power-on control and drive each group of steering drive members 4 to keep the steering fixed or adjust the steering angle.

[0065] It can be understood that the vehicle controller 3 receives the steering command and sends a signal to the steering driver 5, which converts the signal into winding power control and drives each group of steering drive components 4 to operate. The steering angle can be adjusted 360° in the vertical direction, is not limited by the steering angle, has high flexibility, and can be accurately moved to the specified position.

[0066] Specifically, Figure 2 and Figure 4 As shown, the steering drive 4 includes a driving motor 41, a reducer 42 and a bearing 43. The driving motor 41 is arranged on the frame 1. The driving motor 41 is preferably a stepping motor. The rotation angle of the stepping motor is proportional to the number of pulses input. By accurately controlling the number and frequency of pulses, accurate control of position and speed can be achieved. Specifically, the vehicle controller 3 receives the steering instruction, calculates the target number of steps and target direction of the driving motor 41, generates a pulse signal and sends it to the steering driver 5. The power supply provides direct current. The steering driver 5 receives the pulse signal of the vehicle controller 3 and converts it into power-on control of the winding of the driving motor 41. The power-on sequence of the winding is switched according to the set step angle, and a rotating magnetic field is generated to drive the rotor to step motion, thereby achieving precise steering control.

[0067] Furthermore, the reducer 42 is arranged at the output end of the driving motor 41, the race of the bearing 43 is connected to the frame 1, and the shaft race of the bearing 43 is connected to the reducer 42. Figure 4The reducer 42 includes an inner gear ring 421 and a gear 422. The inner gear ring 421 is located in the bearing 43. The outer periphery of the inner gear ring 421 is connected to the inner wall of the shaft ring of the bearing 43. The gear 422 is coaxially connected to the output end of the drive motor 41. The outer periphery of the gear 422 is meshed with the inner wall of the inner gear ring 421. The output end of the drive motor 41 is keyed to the gear 422. Preferably, the bearing 43 is a thrust bearing. The thrust bearing can effectively disperse the steering torque and reduce the rotational friction through high load-bearing capacity, thereby ensuring the smooth operation of the steering device.

[0068] It should be noted that the electronic components mentioned above are the power supply, vehicle controller 3, steering drive 5 and rotation drive 7 of this embodiment, that is, the power supply, vehicle controller 3, steering drive 5 and rotation drive 7 are located in the accommodating cavity.

[0069] The output end of each group of steering drive components 4 in this embodiment is connected to a mobile device, which includes a connecting frame 8, a rotating drive component 6, a rotating driver 7 and a wheel 9. The connecting frame 8 is connected to the output end of the steering drive component 4, and the rotating axis of the wheel 9 is arranged on the connecting frame 8 in a horizontal direction. The output end of the rotating drive component 6 is connected to the wheel 9, and the rotating driver 7 is connected to multiple groups of rotating drive components 6 and the vehicle controller 3. Multiple groups of rotating drive components 6 are independent of each other, and the rotating driver 7 controls multiple groups of rotating drive components 6 to rotate separately without interfering with each other. The vehicle controller 3 is also used to receive the torque and speed instructions required for the acceleration or braking command calculation to the rotating driver 7, and the rotating driver 7 is configured to adjust the current frequency and amplitude of each group of steering drive components 4 in real time according to the torque and speed instructions.

[0070] It can be understood that the vehicle controller 3 receives acceleration or braking instructions and sends a signal to the rotation driver 7. The rotation driver 7 converts the signal into torque and speed instructions to drive each group of rotation drive parts 6 to move, and can adjust the output in real time to achieve efficient and accurate driving and dynamic response, and the movement accuracy is further improved.

[0071] Optionally, the connecting frame 8 is arranged in an "L" shape, and the connecting frame 8 has a horizontal side and a vertical side. The wheel 9 is located on the right angle inner side of the connecting frame 8, and the rotating drive member 6 is connected to the vertical side of the connecting frame 8. The horizontal side of the connecting frame 8 is connected to the inner gear ring 421, that is, it is also connected to the shaft ring. The above-mentioned connection structure design optimizes the force transmission path, improves the transmission efficiency and structural strength of the steering device, and the one-piece connecting frame 8 realizes a high degree of integration of the steering device and the mobile device, and improves the response speed and reliability of the agricultural mobile platform.

[0072] Specifically, Figure 3As shown, the rotating drive member 6 includes a hub motor 61, which is connected to the connecting frame 8, and the wheel 9 is precisely mounted on the output end of the hub motor 61 to form a compact integrated structure, which not only simplifies the structure but also improves the modularization level. By optimizing the force distribution, the operating stability and reliability of the whole vehicle are improved, and it is suitable for efficient operation requirements under various complex working conditions.

[0073] In addition, if Figure 2 As shown, the agricultural mobile platform also includes an inverter 62, which is arranged on the frame 1. The inverter 62 is electrically connected to the power battery 2 and is used to convert direct current into the three-phase alternating current required by the hub motor 61. Specifically, the power supply provides direct current, which is converted into the three-phase alternating current required by the hub motor 61 through the inverter 62. The rotation driver 7 adjusts the current frequency and amplitude according to the instructions of the vehicle controller 3, and the stator winding of the hub motor 61 generates a rotating magnetic field, which interacts with the rotor permanent magnet to drive the wheel 9 to rotate. The whole process is closed-loop controlled by the vehicle controller 3, and the output is adjusted in real time to achieve efficient and accurate drive and dynamic response.

[0074] Preferably, if Figure 5 As shown, four groups of steering devices and moving devices are provided, and the four groups are respectively provided at the four corners of the frame 1. In other embodiments, the number of steering devices and moving devices can also be one, two, three, five or even more, and the specific number can be set according to the needs, and this embodiment does not specifically limit this.

[0075] In summary, by decoupling the steering device and the moving device, each wheel 9 can be controlled individually, providing multiple controllable degrees of freedom, supporting the adjustment of the wheel angles of multiple wheels 9, reducing the weight and structural complexity of the agricultural mobile platform, improving the energy efficiency and maneuverability, and thereby improving the adaptability in confined spaces such as greenhouses, orchards, and three-dimensional plantings.

[0076] Based on the agricultural mobile platform mentioned above, this embodiment further provides a steering control method for the agricultural mobile platform. The steering control method for the agricultural mobile platform includes the following steps:

[0077] The vehicle controller 3 receives the steering command and sends it to the steering driver 5;

[0078] The steering driver 5 correspondingly controls each steering driver 4 to selectively keep the steering fixed or adjust the steering angle;

[0079] The vehicle controller 3 receives the movement instruction and sends it to the rotation driver 7;

[0080] The rotary driver 7 controls the rotation of each rotary drive member 6 accordingly.

[0081] The vehicle controller 3 has at least a front-wheel steering mode, an all-wheel same-direction steering mode, and an in-situ steering mode.

[0082] like Figure 6 As shown, in the front wheel steering mode, the steering drive member 4 located at the front wheel rotates, and the steering drive member 4 located at the rear wheel remains fixed, so that the agricultural mobile platform achieves steering.

[0083] Specifically, the speed of the drive motor 41 satisfies the Ackerman steering model, and the Ackerman front axle center equivalent angle value is calculated as shown in formula (1), and then the target speed of the four wheels 9 is obtained as shown in formula (2). The Ackerman differential steering is achieved by controlling the speed of the drive motor 41.

[0084]

[0085] Where δ1 is the front wheel outer steering angle, δ is the equivalent turning angle of the front axle center, L is the wheelbase, B is the distance from the rear axle to the center of mass, C is the wheelbase, V is the current vehicle speed, and v i is the rotation speed of the four wheels 9, i=1, 2, 3, 4.

[0086] When the agricultural mobile platform turns, the inner wheel 9 needs to bear more lateral force, so the slip of the inner wheel 9 will increase and it is easy to enter an unstable state. The actual slip rate of the wheel 9 is shown in formula (3).

[0087]

[0088] Where λ i is the actual slip rate, r is the radius of wheel 9, w i is the angular velocity of wheel 9.

[0089] The above formula (3) is derived and combined with the longitudinal force balance equation to obtain formula (4).

[0090]

[0091] Where F xi is the longitudinal force of wheel 9, T i is the motor torque, is the longitudinal disturbance, w is the angular velocity of wheel 9, J w is the equivalent moment of inertia of wheel 9.

[0092] Formula (5) can be obtained by rearranging formula (4).

[0093]

[0094] In order to ensure the steering stability and safety of the agricultural mobile platform, an integral robust controller is used to track and control the actual slip rate of the wheel 9. To facilitate the design of the control torque, the longitudinal force disturbance D(t) is set to 0. The slip rate error e and the sliding mode variable p shown in the following equation (6) are defined to meet the design of the control torque.

[0095]

[0096] Where λ id is the ideal slip ratio, and k is the positive gain.

[0097] Substituting the above formula (6) into formula (7) we can obtain formula (7).

[0098] p=g i (λ i ,v)+h i (λ,v)T i +D(t)-λ id +ke(7)

[0099] According to formula (7), the integral robust controller is designed to obtain formula (8).

[0100]

[0101] Where k1 is the positive gain, T ia is the adaptive compensation term, T is is the robust feedback term, T is1 is the proportional feedback term used to stabilize the system, T is2 is the integral robust term. Due to the nonlinear factors of uncertainty, the linear feedback term alone cannot achieve a good control effect. Therefore, the integral robust term is used to reduce uncertainty. The specific expression is formula (9).

[0102]

[0103] Where k r and β are both positive gains.

[0104] Integrating formula (9) to obtain the slip rate control torque gives formula (10).

[0105]

[0106] The steering radius of the front-wheel steering mode is determined by the front-wheel steering angle and the platform wheelbase, which is suitable for straight-line driving and large-radius turning operations in a spacious environment, such as field cruising or simple path movement in a greenhouse. Its simple structure and easy control are its significant advantages, and it performs well in high-speed driving or operations requiring high stability.

[0107] like Figure 7As shown, in the all-wheel same-direction steering mode, the steering drive components 4 of the front wheels and the rear wheels rotate in the same direction and angle, and the agricultural mobile platform achieves lateral translation (crab crawling motion).

[0108] Specifically, for all-wheel drive, each wheel 9 is powered by independent driving, and the four wheels 9 rotate at the same speed as shown in formula (11), thereby improving traction and passability. This mode is suitable for scenarios requiring high flexibility in facility agriculture, such as narrow passages in greenhouses, operations between fruit trees, or precise field scheduling.

[0109] v1=v2=v3=v4(11)

[0110] like Figure 8 As shown, in the in-situ steering mode, the steering drive components 4 of the wheels 9 located on both sides of the frame 1 rotate in opposite directions respectively, and the agricultural mobile platform achieves in-situ rotation.

[0111] Specifically, the wheels 9 on the left and right sides can rotate in opposite directions, and the absolute value of the rotation angle of the wheels 9 is shown in formula (12), so that the platform can rotate in situ, that is, zero turning radius. This steering method combines the advantages of rotating in situ and independent driving of each wheel 9, providing extremely high flexibility and precise control, and is suitable for rapid adjustment and fine work in a small space.

[0112]

[0113] In summary, the distributed mobile device driven by the wheel hub motor 61 and the lightweight distributed steering device are combined to achieve a high degree of integration between the mobile device and the steering device through innovative design. Accurate power output and efficient steering control are achieved. Independent drive enhances vehicle stability and passability, and distributed steering improves mobility and adapts to a variety of complex operating scenarios.

[0114] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. An agricultural mobile platform, comprising a frame (1), characterized in that: The agricultural mobile platform also includes a power source, a vehicle controller (3), a steering device and a moving device; The steering device comprises a plurality of steering drive components (4) and a steering driver (5); the rotation axis of the steering drive components (4) is arranged on the vehicle frame (1) along a vertical direction; and the steering driver (5) is communicatively connected with the plurality of steering drive components (4) and the vehicle controller (3); The vehicle controller (3) is used to receive a steering instruction, calculate a target number of steps and a target direction, and send a signal to the steering driver (5); the steering driver (5) is used to convert the signal into a winding power supply control and drive each group of the steering drive components (4) to keep the steering fixed or adjust the steering angle; The output end of each group of the steering drive members (4) is connected to the mobile device, and the mobile device comprises a connecting frame (8), a rotating drive member (6), a rotating driver (7) and a wheel (9), the connecting frame (8) is connected to the output end of the steering drive member (4), the rotating axis of the wheel (9) is arranged on the connecting frame (8) along the horizontal direction, the output end of the rotating drive member (6) is connected to the wheel (9), and the rotating driver (7) is communicatively connected with the plurality of groups of the rotating drive members (6) and the vehicle controller (3); The vehicle controller (3) is also used to receive torque and speed instructions required for calculating acceleration or braking instructions to the rotation driver (7), and the rotation driver (7) is configured to adjust the current frequency and amplitude of each group of steering drive components (4) in real time according to the torque and speed instructions.

2. The agricultural mobile platform according to claim 1, characterized in that: The steering drive member (4) comprises: A drive motor (41), wherein the drive motor (41) is arranged on the vehicle frame (1); A reducer (42), wherein the reducer (42) is arranged at an output end of the drive motor (41); A bearing (43), the seat ring of the bearing (43) is connected to the frame (1), the shaft ring of the bearing (43) is connected to the reducer (42), and the connecting frame (8) is connected to the shaft ring of the bearing (43).

3. The agricultural mobile platform according to claim 2, characterized in that: The reducer (42) comprises: An inner gear ring (421), the inner gear ring (421) is located in the bearing (43), and the outer periphery of the inner gear ring (421) is connected to the inner wall of the shaft ring of the bearing (43); A gear (422), the gear (422) is coaxially connected to the output end of the drive motor (41), and the outer periphery of the gear (422) is meshed with the inner wall of the inner gear ring (421).

4. The agricultural mobile platform according to claim 1, characterized in that: The rotating drive member (6) comprises a wheel hub motor (61), the wheel hub motor (61) is connected to the connecting frame (8), and the output end of the wheel hub motor (61) is connected to the wheel (9).

5. The agricultural mobile platform according to claim 4, characterized in that: The power source comprises a power battery (2), and the agricultural mobile platform further comprises an inverter (62). The inverter (62) is arranged on the frame (1), and the inverter (62) is electrically connected to the power battery (2) and is used to convert direct current into three-phase alternating current required by the wheel hub motor (61).

6. The agricultural mobile platform according to any one of claims 1 to 5, characterized in that: The connecting frame (8) is arranged in an L shape, and the wheel (9) is located at the right-angled inner side of the connecting frame (8).

7. The agricultural mobile platform according to any one of claims 1 to 5, characterized in that: The steering device and the moving device are both provided with four groups, and the four groups are respectively arranged at the four corners of the frame (1).

8. The agricultural mobile platform according to any one of claims 1 to 5, characterized in that: The frame (1) is covered with a vehicle body cover (11), a receiving cavity is formed between the vehicle body cover (11) and the frame (1), and the power supply, the vehicle controller (3), the steering drive (5) and the rotation drive (7) are located in the receiving cavity.

9. A steering control method for an agricultural mobile platform, implemented based on the agricultural mobile platform according to any one of claims 1 to 8, characterized in that: The agricultural mobile platform steering control method comprises the following steps: The vehicle controller (3) receives the steering instruction and sends it to the steering driver (5); The steering driver (5) correspondingly controls each steering driver (4) to selectively keep the steering fixed or adjust the steering angle; The vehicle controller (3) receives the movement instruction and sends it to the rotation driver (7); The rotary driver (7) controls the rotation of each rotary drive member (6) accordingly.

10. The steering control method of the agricultural mobile platform according to claim 9, characterized in that: The vehicle controller (3) has at least a front-wheel steering mode, an all-wheel same-direction steering mode, and an in-situ steering mode; In the front wheel steering mode, the steering drive member (4) located at the front wheel rotates, and the steering drive member (4) located at the rear wheel remains fixed, so that the agricultural mobile platform achieves steering; In the all-wheel same-direction steering mode, the steering drive members (4) of the front wheels and the rear wheels rotate in the same direction and angle, and the agricultural mobile platform achieves lateral translation; In the in-situ steering mode, the steering drive components (4) of the wheels (9) located on both sides of the frame (1) rotate in opposite directions respectively, so that the agricultural mobile platform can rotate in-situ.

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