Self-leveling AGV adapting to concave-convex ground and leveling method thereof

Abstract

The self-leveling AGV comprises front wheel assemblies, rear wheel assemblies, a frame assembly, an inclination sensor and a control system, the two front wheel assemblies are arranged on the two sides of the front end of the frame assembly, the rear wheel assemblies are located in the middle of the rear side of the frame assembly, and the inclination sensor and the control system are installed on the frame assembly. The front wheel assembly comprises a driving device, a steering device and a leveling device. The driving balance and stability of the AGV trolley are ensured when the AGV trolley runs on the uneven ground, and when the AGV trolley runs on the uneven ground, the AGV trolley is adaptive to the ground and can be actively leveled, and an AGV body does not incline; during high-precision butt joint, deviation is avoided, so that production accidents are prevented; the obstacle crossing and climbing capabilities are high; the structure is relatively simple and clear, the manufacturing and using cost is low, and the occupied space is small; the robot can walk straightly or transversely conveniently, can rotate by 360 degrees in situ, is higher in flexibility, and improves the moving and posture adjusting efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent equipment, and in particular to a self-propelled vehicle AGV, in particular to a self-leveling AGV adapting to uneven ground and a leveling method thereof. Background Art

[0002] With the rapid development of the AGV industry, AGV is no longer just engaged in handling operations, but is gradually developing into the field of automation as a robot chassis with high-precision docking. At present, AGV generally adopts a four-wheel structure. When the ground is uneven, when one of the wheels passes through a pit or convex bump on the ground, it will cause the wheel to be suspended or the frame to tilt, affecting the operation of the vehicle. In order to solve the problems of insufficient grip of the driving wheel and wheel slippage caused by uneven road surface, a suspended drive structure or a bridge drive structure is mainly used. The main principle of these two types of drive structures is to use springs or articulated bridges to enable the driving wheels and universal wheels to all touch the ground, so that they can run normally on uneven ground.

[0003] Patent CN114715282A discloses an AGV chassis that is adaptive to the ground and can be actively leveled. A bridge-type front wheel assembly is arranged on the frame assembly. The bridge is hinged to the frame assembly through a bridge hinge shaft. The bridge hinge shaft is passed through the middle of the bridge. The first steering wheel and the first universal wheel are respectively installed at both ends of the bridge, so that when passing through uneven ground, the bridge can rotate around the bridge hinge shaft, thereby driving the first steering wheel and the first universal wheel to move together, so that at least one of the first steering wheel and the first universal wheel is in contact with the ground, preventing the wheels from not touching the ground.

[0004] Although the chassis of the above-mentioned AGV can meet the leveling requirements, the bridge and the frame welding assembly are hinged, and the unstable balance affects the high-precision docking; secondly, the bridge structure is complex, the operation is cumbersome, the manufacturing cost and the use cost are high, and it will take up space, which is not conducive to the passage of structures such as wires. In addition, the motor of the steering wheel assembly is low to the ground, and the passability is poor in some occasions, which is not conducive to working in an environment with accumulated water.

[0005] CN112810708B discloses a multifunctional agricultural all-terrain electric vehicle, and CN 219361193U discloses an all-terrain transport vehicle capable of real-time leveling. Both adopt crawler technology to solve the problem of walking on uneven ground, but have not yet solved the problem of high-precision leveling and flexible steering, especially in a smaller space, where flexible steering can improve efficiency.

[0006] Especially when AGV is used as a robot-bearing chassis, it needs to carry the fuselage and the end effector. The stability on uneven ground becomes a key indicator of the robot's operating safety. In addition, the driven characteristics of the universal wheel and the poor stability on rugged roads will cause the driving route to deviate. CN219654195U provides a wall construction robot, in which an AGV-like chassis is used to support the robot body and the end effector. The AGV-like chassis is provided with 4 wheels to achieve forward, backward, left and right movement. In addition, 3 chassis leveling electric cylinders are provided at the bottom of the chassis. The three chassis leveling electric cylinders can support the robot and adjust the robot's posture to a horizontal state according to the tilt sensor installed on the robot. Although it solves the problem of high-precision leveling, its structure is complex and it does not solve the leveling problem while moving, so it is not practical for bumpy roads.

[0007] In summary, it is necessary to provide an automatic leveling AGV with low cost, suitable for bumpy roads, easy to turn, automatic leveling, small space occupation and reasonable structure. Summary of the invention

[0008] In order to solve the above technical problems, the present invention designs a self-leveling AGV that adapts to uneven terrain and a leveling method thereof. The AGV can adapt to the terrain and can actively level itself, can overcome obstacles and climb slopes, and can also overcome torque to move on uneven terrain, and can conveniently walk straight and sideways.

[0009] The present invention adopts the following technical solution: A self-leveling AGV adapted to uneven ground, characterized in that it includes a front wheel assembly, a rear wheel assembly, a frame assembly, a tilt sensor, and a control system. The two front wheel assemblies are arranged on both sides of the front end of the frame assembly, and the rear wheel assembly is located in the center of the rear side of the frame assembly. The tilt sensor and the control system are installed on the frame assembly. The front wheel assembly includes a drive device, a steering device, and a leveling device. When the AGV is used as a robot chassis, the tilt sensor can also be arranged on the robot body or the end effector.

[0010] Preferably, the rear wheel assembly includes a driving device, a steering device and a leveling device.

[0011] Preferably, the rear wheel assembly includes a driving device and a steering device.

[0012] Preferably, the frame assembly includes a main frame, a front wheel bracket and a rear wheel bracket, the front wheel bracket is fixed on both sides of the front end of the main frame, the front wheel bracket is connected to the front wheel assembly, and a rear wheel bracket is arranged in the middle of the rear end of the main frame, and the rear wheel bracket is connected to the rear wheel assembly.

[0013] Preferably, the driving device includes a driving wheel, a driving wheel bracket, a driving wheel center axis and a tubular support shaft, the driving wheel center axis is fixedly supported at the bottom of the driving wheel bracket, the driving wheel is rotatably connected to the driving wheel center axis, and the tubular support shaft is fixed at the top center of the driving wheel bracket.

[0014] Preferably, the steering device includes a steering motor, a steering reducer, a steering bevel gear, and a steering driven bevel gear. The steering motor drives the steering bevel gear through the steering reducer. The steering bevel gear is meshed with the steering driven bevel gear. The steering driven bevel gear is used to adjust the steering of the drive device.

[0015] Preferably, the leveling device includes a leveling motor, a leveling reducer, a leveling bevel gear, a leveling driven bevel gear, a leveling screw, a screw nut, a leveling telescopic seat, and a screw bearing. The top of the leveling screw has a section of a light rod, forming a support for supporting the bearing seat through the screw bearing. The bearing seat is fixedly connected to the front wheel bracket or the rear wheel bracket of the frame assembly. The leveling motor is connected to drive the leveling bevel gear through the leveling reducer. The leveling bevel gear is meshed with the leveling driven bevel gear. The leveling driven bevel gear drives the leveling screw to rotate through the key shaft. The leveling screw is threadedly connected to the screw nut, and the screw nut is fixedly connected to the leveling telescopic seat. The front wheel bracket or the rear wheel bracket of the frame assembly is equipped with a linear slide rail connected to a slider fixed on the leveling telescopic seat. During leveling, the screw nut supported by the leveling telescopic seat maintains a constant height, and the leveling screw moves up and down, driving the front wheel bracket or the rear wheel bracket to rise or fall through the bearing seat. Thus, the inclination angle of the entire frame assembly can be adjusted to achieve the purpose of leveling.

[0016] Preferably, the leveling device is arranged above the rotating device, and the driving device is arranged below the steering device. The inner diameter of the tubular support shaft of the driving device is larger than the outer diameter of the leveling screw, and the axial projection of the leveling screw is located in the hollow of the tubular support shaft.

[0017] Preferably, the main frame is formed by welding rectangular tubes and sheet metal.

[0018] A leveling method, applicable to the above-mentioned self-leveling AGV adapting to uneven ground, comprises the following steps: S1. System original balance point setting: standard operating state set at the factory, recording tilt sensor data; S2, system leveling determination: real-time testing and detection of tilt sensor data, obtaining the actual measured current state of the front and rear tilt angle and left and right tilt angle, and comparing the current state data with the original set tilt sensor data. If they are consistent, no adjustment is required. If they are inconsistent, subsequent leveling steps are required; S3. Leveling point selection: Select the number of leveling points according to the model, and select the two-point leveling mode or the three-point leveling mode, that is, select according to whether there are two-point leveling devices or three-point leveling devices. If there are two-point leveling devices, select the two-point leveling mode, and if there are three-point leveling devices, select the three-point leveling mode; S4. Leveling execution: Two-point leveling mode: Get the current position of the leveling screw, take the support point without the leveling device as the base point, calculate the adjustment height of the other two points to the base point, perform height adjustment, and complete the leveling. If the leveling cannot be completed, the tilt exceeds the adjustable range and an alarm is issued; Three-point leveling mode: Get the current position of the leveling screw and set the base point with the three-point algorithm, that is, confirm a regression range in advance. If only one point is within the range, select this point as the base point. If two or more points are within the range, select the point close to the middle position in the range as the base point. If none of them are within the range, select the point closest to the range as the base point, calculate the adjustment height of the remaining two points to the base point, perform height adjustment, and complete leveling. Of course, in extreme conditions, if the base point is confirmed by the regression range method, when at least one point is at the extreme position of the adjustment, the leveling goal is still not achieved, then select the point at the extreme position of the adjustment as the base point, and then calculate the adjustment height of the remaining two points to the reference leveling, perform height adjustment, and complete leveling. If leveling still cannot be achieved, the tilt exceeds the adjustable range and an alarm is issued; S5. Continue to measure the tilt sensor data in real time during the movement of the AGV, and repeat steps S1-S4.

[0019] The leveling principle of the self-leveling AGV that can adapt to uneven ground is that when the tilt sensor detects deviation, the control system instructs the leveling motor to work, and the leveling bevel gear drives the driven leveling bevel gear through the leveling reducer, which drives the leveling screw to rotate, making the part above the screw nut longer or shorter, driving the frame assembly to move up and down. The relative position change of the three screw nuts can adjust the tilt angle to achieve the purpose of leveling, or one drive wheel remains unchanged, and the other two drive wheel assemblies perform the leveling action, which can also achieve leveling. Of course, if the rear wheel assembly only includes a drive device and a steering device, the rear wheel assembly is used as the unchanged point, and the other two front wheel assemblies perform the leveling action.

[0020] The beneficial effects of the present invention are: (1) ensuring the driving balance and stability of the AGV when running on uneven ground. When walking on uneven roads, it can adapt to the ground and actively level the AGV body without tilting; in high-precision docking, no deviation will occur, thereby preventing production accidents; (2) strong obstacle crossing and climbing capabilities; (3) relatively simple and clear structure, low manufacturing and use costs, and small space occupancy; (4) conveniently moving straight or sideways, and can also achieve 360° rotation on the spot, with higher flexibility and improved movement and posture adjustment efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a schematic diagram of the structure of the front drive wheel assembly of the present invention; Figure 3 It is a cross-sectional schematic diagram of the drive wheel assembly of the present invention; Figure 4 is a schematic structural diagram of a rear wheel assembly of the present invention; Figure 5 is a cross-sectional schematic diagram of the rear wheel assembly of the present invention; Figure 6 It is a structural schematic diagram showing the parameters of wheelbase L and track W in the present invention; Figure 7 It is a structural schematic diagram showing the parameter inclination angle α in the present invention; Figure 8 It is a structural schematic diagram showing the parameter bevel angle β in the present invention; Fig. 9 It is a process flow chart of the leveling method of the present invention; In the figure: 1, front wheel assembly, 2, rear wheel assembly, 3, frame assembly, 4, tilt sensor, 5, control system, 10, front wheel drive device, 101, drive wheel, 102, drive wheel bracket, 103, drive wheel center shaft, 104, tubular support shaft, 11, front wheel steering device, 111, steering motor, 112, steering reducer, 113, steering bevel gear, 114, steering driven bevel gear, 115, steering bearing, 12, front wheel leveling device, 121, leveling Motor, 122, leveling reducer, 123, leveling bevel gear, 124, leveling driven bevel gear, 125, leveling screw, 126, screw nut, 127, leveling telescopic seat, 128, screw bearing, 129, bearing seat, 20, rear wheel drive device, 21, rear wheel steering device, 30, main frame, 31, front wheel bracket, 311, linear slide rail, 312, slider, 313, front side plate, 314, left side plate, 315, right side plate, 32, rear wheel support plate. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is further described in detail below through specific embodiments and in conjunction with the accompanying drawings: Example 1: Figure 1 As shown, a self-leveling AGV that can adapt to uneven terrain includes a front wheel assembly 1, a rear wheel assembly 2, a frame assembly 3, a tilt sensor 4, and a control system 5. The two front wheel assemblies are arranged on both sides of the front end of the frame assembly, and the rear wheel assembly is located in the center of the rear side of the frame assembly. The tilt sensor and the control system are installed on the frame assembly.

[0023] The frame assembly 3 consists of a main frame 30, a front wheel bracket 31, and a rear wheel bracket. The main frame 30 is welded by rectangular tubes and sheet metal, connecting all components to form a whole, bearing the weight of transported items or supporting the robot body and the end effector; the front wheel bracket 31 is fixed on both sides of the front end of the main frame 30, and is composed of a front side plate 313, a left side plate 314, and a right side plate 315. A rear wheel bracket is provided in the middle of the rear end of the main frame 30 for connecting the rear wheel assembly; the tilt sensor 4 and the control system 5 are arranged on the main frame 30.

[0024] like Figure 2 and Figure 3 As shown, the front wheel assembly 1 includes a front wheel drive device 10, a front wheel steering device 11 and a front wheel leveling device 12. The front wheel drive device 10 includes a driving wheel 101, a driving wheel bracket 102, a driving wheel center shaft 103 and a tubular support shaft 104. The driving wheel center shaft 103 is fixedly supported at the bottom of the driving wheel bracket 102, the driving wheel 101 is rotatably connected to the driving wheel center shaft 103, and the tubular support shaft 104 is fixed to the top center of the driving wheel bracket 102.

[0025] The front wheel steering device 11 comprises a steering motor 111, a steering reducer 112, a steering bevel gear 113, a steering driven bevel gear 114, and a steering bearing 115. The steering motor 111 drives the steering bevel gear 113 through the steering reducer 112, the steering bevel gear 113 is meshed with the steering driven bevel gear 114, and the steering driven bevel gear 114 is fixed to the top of the tubular support shaft 104. When rotating, the steering motor 111 drives the steering bevel gear 113 through the steering reducer 112, the steering bevel gear 113 drives the steering driven bevel gear 114, and the steering driven bevel gear 114 drives the tubular support shaft 104 to rotate, thereby driving the driving wheel 101 to rotate.

[0026] The front wheel leveling device 12 includes a leveling motor 121, a leveling reducer 122, a leveling bevel gear 123, a leveling driven bevel gear 124, a leveling screw 125, a screw nut 126, a leveling telescopic seat 127, and a screw bearing 128. The top of the leveling screw 125 has a section of a bare rod, which forms a support for supporting a bearing seat 129 through a screw bearing 128. The bearing seat 129 is fixedly connected to the front wheel bracket 31. The leveling motor 121 is connected to drive the leveling bevel gear 123 through the leveling reducer 122. The leveling bevel gear 123 is meshed with the leveling driven bevel gear 124. The leveling driven bevel gear 124 is matched with the key shaft. The leveling screw 125 is driven to rotate, and the screw nut 126 is threadedly connected to the leveling screw 125. The tubular support shaft 104 is connected to support the leveling telescopic seat 127 through two steering bearings 115. The screw nut 126 is fixedly connected to the leveling telescopic seat 127. The front side plate 313, the left side plate 314, and the right side plate 315 of the front wheel bracket 31 are equipped with a linear slide rail 311 connected to the slider 312 fixed on the leveling telescopic seat 127. When leveling, the screw nut 126 supported by the leveling telescopic seat 127 keeps the same height, and the leveling screw 125 will move up and down, driving the front wheel bracket 31 to rise or fall through the bearing seat 129. In this way, the inclination angle of the entire frame assembly can be adjusted to achieve the purpose of leveling.

[0027] The inner diameter of the tubular support shaft 104 is larger than the outer diameter of the leveling screw 125 , and the lower end of the leveling screw 125 can enter the hollow of the tubular support shaft 104 , thereby reducing the vertical space of the system and facilitating the arrangement of the front wheel leveling device 12 .

[0028] like Figure 4 and Figure 5 As shown, the rear wheel assembly 2 includes a rear wheel drive device 20 and a rear wheel steering device 21; the rear wheel drive device 20 is similar to the front wheel drive device 10 and consists of a driving wheel 101, a driving wheel bracket 102, a driving wheel central axis 103, and a rear wheel support shaft 204. The driving wheel central axis 103 of the rear wheel drive device 20 supports the bottom of the driving wheel bracket 102, and the rear wheel support shaft 204 is fixed to the top center of the driving wheel bracket 102. The rear wheel support shaft 204 is connected to the support seat through two steering bearings. At this time, the rear wheel bracket is a rear wheel support plate, and the support seat is fixedly connected to the rear wheel support plate 32. The rear wheel steering device 21 is the same as the front wheel steering device. The front wheel steering device and the rear wheel steering device are driven to facilitate the AGV to move straight or sideways, and can also achieve 360° rotation in situ, which is more flexible and improves the efficiency of movement and posture adjustment.

[0029] Two front wheel assemblies 1 and one rear wheel assembly 2 form a three-wheel structure, so there will be no situation where the wheels are not touching the ground. At the same time, all three wheels are driving wheels with sufficient driving force. At the same time, all three wheels have steering devices, and the walking mode can be flexibly designed. Whether it is moving forward or sideways, it can have excellent displacement accuracy and improve overall efficiency.

[0030] After the robot chassis of the present invention supports the robot body and the end effector to enter the workstation, before performing high-precision docking operations, the tilt sensor 4 will detect the values ​​of the frame assembly 3 in various directions, and compare the values ​​with the set standard positions to obtain the difference. The control system 5 will instruct the leveling device to work, thereby ensuring the posture of the entire AGV body, performing high-precision docking operations, and avoiding production accidents.

[0031] like Fig. 9 As shown, the leveling method of this embodiment includes the following steps: S1. System original balance point setting: standard operating state set at the factory, recording tilt sensor data; S2, system leveling determination: real-time testing and detection of tilt sensor data, obtaining the actual measured current state of the front and rear tilt angle and left and right tilt angle, and comparing the current state data with the original set tilt sensor data. If they are consistent, no adjustment is required. If they are inconsistent, subsequent leveling steps are required; S3, leveling point selection: select the leveling points according to the model, and select the two-point leveling mode; S4. Leveling execution: Two-point leveling mode: Get the current position of the leveling screw, take the support point without the leveling device as the base point, calculate the adjustment height of the other two points to the base point, perform height adjustment, and complete the leveling. If the leveling cannot be completed, the tilt exceeds the adjustable range and an alarm is issued; S5. Continue to measure the tilt sensor data in real time during the movement of the AGV, and repeat steps S1-S4.

[0032] like Figure 6-Figure 8 As shown, W = the distance between the driving wheel centers of the two front wheel assemblies, L = the vertical distance from the driving wheel center of the rear wheel assembly to the connecting line of the driving wheel centers of the two front wheel assemblies, α = the current front-to-back tilt angle - the factory calibrated tilt angle, β = the current left-right tilt angle - the factory calibrated tilt angle, K is the correction coefficient; P 倾角调节 = L*sinα* K;P 斜角调节 = (W / 2)*sinβ* K;P 左前轮支架目标位置 =P 左前轮支架当前位置 + P 倾角调节 + P 斜角调节 ;P 右前轮支架目标位置 =P 右前轮支架当前位置 + P 倾角调节 -P斜角调节 ; Among them, P 倾角调节 is the distance of tilt adjustment, P 斜角调节 is the distance of bevel adjustment, P 左前轮支架目标位置 is the target position of the left front wheel support, P 右前轮支架当前位置 is the target position value of the right front wheel bracket.

[0033] When the AGV is leveled, the rear wheel assembly becomes the base point, and the value P of the target position of the left front wheel bracket is calculated by the above formula. 左前轮支架目标位置 and the value P of the target position of the right front wheel bracket 右前轮支架目标位置 ; The control system is given a signal and the movement is executed, and the above calculation and movement process are repeated until the deviations of the inclination and bevel angles are less than the preset allowable deviations, completing the entire leveling process.

[0034] Taking the actual calculation process as an example, if W= 600mm, L=480mm, the factory calibrated inclination angle is 0.1°, the factory calibrated bevel angle is 0.08°, K is 0.5, the actual measured current front-to-back inclination angle is 0.5°, and the current left-to-right bevel angle is 0.6°.

[0035] The above formula can be used to calculate: α=0.5-0.1=0.4°, β=0.6-0.08=0.52°, P 倾角调节 =480mm*sin0.4 °*0.5=1.68 mm, P 斜角调节 = (600mm / 2)*sin0.52° * 0.5=1.37mm, P 左前轮支架目标位置 =P 左前轮支架当前位置 + P 倾角调节 + P 斜角调节 , P 左前轮支架当前位置 Initially, it is 0, P 左前轮支架目标位置 =0+1.68 mm+1.37 mm=3.05 mm, similarly P 右前轮支架当前位置 Initially, it is 0, P 右前轮支架目标位置 = 0+1.68mm - 1.37mm=0.31mm.

[0036] Then use the rear wheel assembly as the base point for leveling. 左前轮支架当前位置 =3.05mm, P 右前轮支架目标位置 =0.31mm, and then perform subsequent leveling until the deviations of the inclination and bevel angles are both less than the preset allowable deviation of 0.05°, completing the entire leveling process.

[0037] Embodiment 2: A self-leveling AGV that can adapt to uneven terrain, wherein the rear wheel assembly is consistent with the front wheel assembly and is also provided with a leveling device, and other structures are the same as those of Embodiment 1.

[0038] like Fig. 9 As shown, the leveling method of this embodiment includes the following steps: S1. System original balance point setting: standard operating state set at the factory, recording tilt sensor data; S2, system leveling determination: real-time testing and detection of tilt sensor data, obtaining the actual measured current state of the front and rear tilt angle and left and right tilt angle, and comparing the current state data with the original set tilt sensor data. If they are consistent, no adjustment is required. If they are inconsistent, subsequent leveling steps are required; S3, leveling point selection: select the leveling points according to the model, and select the three-point leveling mode; S4. Leveling execution: Three-point leveling mode: Get the current position of the leveling screw and set the base point with the three-point algorithm, that is, confirm a regression range in advance. If only one point is within the range, select this point as the base point. If two or more points are within the range, select the point close to the middle position in the range as the base point. If none of them are within the range, select the point closest to the range as the base point, calculate the adjustment height of the remaining two points to the base point, perform height adjustment, and complete leveling. Of course, in extreme conditions, if the base point is confirmed by the regression range method, when at least one point is at the extreme position of the adjustment, the leveling goal is still not achieved, then select the point at the extreme position of the adjustment as the base point, and then calculate the adjustment height of the remaining two points to the reference leveling, perform height adjustment, and complete leveling. If leveling still cannot be achieved, the tilt exceeds the adjustable range and an alarm is issued; S5. Continue to measure the tilt sensor data in real time during the movement of the AGV, and repeat steps S1-S4.

[0039] Compared with the two-point leveling mode, the three-point leveling mode requires that all three wheels of the front and rear wheel assemblies have the leveling function. Although the cost will increase, if the three-point leveling mode can select the one in the middle as the base point to adjust the other two points, the efficiency will be greatly improved compared with the two-point leveling mode; if the other three points can be adjusted, the adjustable tilt range is much larger than the two-point leveling mode. In addition, the design idea of ​​the return range is also to prevent the three points from being at one end, which reduces the leveling efficiency.

[0040] The above-described embodiment is only a preferred solution of the present invention and does not limit the present invention in any form. There are other variations and modifications without exceeding the technical solution described in the claims.

Claims

1. A self-leveling AGV that can adapt to uneven ground, characterized by: It includes a front wheel assembly, a rear wheel assembly, a frame assembly, a tilt sensor, and a control system. The two front wheel assemblies are arranged on both sides of the front end of the frame assembly, and the rear wheel assembly is located in the center of the rear side of the frame assembly. The tilt sensor and the control system are installed on the frame assembly. The front wheel assembly includes a driving device, a steering device, and a leveling device.

2. The self-leveling AGV adapted to uneven terrain according to claim 1 is characterized in that: The rear wheel assembly includes a driving device, a steering device and a leveling device.

3. The self-leveling AGV adapted to uneven terrain according to claim 1 is characterized in that: The rear wheel assembly includes a driving device and a steering device.

4. The self-leveling AGV adapted to uneven terrain according to claim 1 is characterized in that: The frame assembly includes a main frame, a front wheel bracket and a rear wheel bracket. The front wheel bracket is fixed on both sides of the front end of the main frame and connected to the front wheel assembly. A rear wheel bracket is arranged in the middle of the rear end of the main frame and connected to the rear wheel assembly.

5. The self-leveling AGV adapted to uneven terrain according to claim 1, 2 or 3, characterized in that: The driving device includes a driving wheel, a driving wheel bracket, a driving wheel central axis and a tubular support shaft. The driving wheel central axis is fixedly supported at the bottom of the driving wheel bracket, the driving wheel is rotatably connected to the driving wheel central axis, and the tubular support shaft is fixed at the top center of the driving wheel bracket.

6. The self-leveling AGV adapted to uneven terrain according to claim 1, 2 or 3, characterized in that: The steering device comprises a steering motor, a steering reducer, a steering bevel gear, and a steering driven bevel gear. The steering motor drives the steering bevel gear through the steering reducer. The steering bevel gear meshes with the steering driven bevel gear. The steering driven bevel gear is used to adjust the steering of the driving device.

7. The self-leveling AGV adapted to uneven terrain according to claim 1 or 2, characterized in that: The leveling device includes a leveling motor, a leveling reducer, a leveling bevel gear, a leveling driven bevel gear, a leveling screw, a screw nut, a leveling telescopic seat, and a screw bearing. A section of light rod is provided at the top of the leveling screw to form a support for supporting the bearing seat through the screw bearing. The bearing seat is fixedly connected to the front wheel bracket or the rear wheel bracket of the frame assembly. The leveling motor is connected to drive the leveling bevel gear through the leveling reducer. The leveling bevel gear is meshed with the leveling driven bevel gear. The leveling driven bevel gear drives the leveling screw to rotate through the key shaft. The leveling screw is threadedly connected to the screw nut, and the screw nut is fixedly connected to the leveling telescopic seat. A linear slide rail is installed on the front wheel bracket or the rear wheel bracket of the frame assembly and is connected to a slider fixed on the leveling telescopic seat. When leveling, the screw nut supported by the leveling telescopic seat maintains a constant height, and the leveling screw will move up and down, driving the front wheel bracket or the rear wheel bracket to rise or fall through the bearing seat.

8. The self-leveling AGV adapted to uneven terrain according to claim 1 is characterized in that: The leveling device is arranged above the steering device, and the driving device is arranged below the steering device.

9. The self-leveling AGV adapted to uneven terrain according to claim 4 is characterized in that: The main frame is formed by welding rectangular tubes and sheet metal.

10. A leveling method, applicable to a self-leveling AGV adapted to uneven terrain as claimed in any one of claims 1 to 9, characterized in that: The following steps are involved: S1. System original balance point setting: standard operating state set at the factory, recording tilt sensor data; S2, system leveling determination: real-time testing and detection of tilt sensor data, obtaining the actual measured current state of the front and rear tilt angle and left and right tilt angle, and comparing the current state data with the original set tilt sensor data. If they are consistent, no adjustment is required. If they are inconsistent, subsequent leveling steps are required; S3. Leveling point selection: Select the number of leveling points according to the model, and select the two-point leveling mode or the three-point leveling mode, that is, select according to whether there are two-point leveling devices or three-point leveling devices. If there are two-point leveling devices, select the two-point leveling mode, and if there are three-point leveling devices, select the three-point leveling mode; S4. Leveling execution: Two-point leveling mode: Get the current position of the leveling screw, take the support point without the leveling device as the base point, calculate the adjustment height of the other two points to the base point, perform height adjustment, and complete the leveling. If the leveling cannot be completed, the tilt exceeds the adjustable range and an alarm is issued; Three-point leveling mode: Get the current position of the leveling screw and set the base point with the three-point algorithm, that is, confirm a regression range in advance. If only one point is within the range, select this point as the base point. If two or more points are within the range, select the point close to the middle position in the range as the base point. If none of them are within the range, select the point closest to the range as the base point, calculate the adjustment height of the remaining two points to the base point, perform height adjustment, and complete leveling. Of course, in extreme conditions, if the base point is confirmed by the regression range method, when at least one point is at the extreme position of the adjustment, the leveling goal is still not achieved, then select the point at the extreme position of the adjustment as the base point, and then calculate the adjustment height of the remaining two points to the reference leveling, perform height adjustment, and complete leveling. If leveling still cannot be achieved, the tilt exceeds the adjustable range and an alarm is issued; S5. Continue to measure the tilt sensor data in real time during the movement of the AGV, and repeat steps S1-S4.

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