Railway dual switch chassis and working method thereof

Abstract

The application relates to a rail dual-purpose switching chassis and a working method thereof. The rail dual-purpose switching chassis is matched with a rail in a greenhouse, the rail is arranged along an inter-ridge rail road surface, end portions of the rail are arranged on a center road surface, the inter-ridge rail road surface is lower than the center road surface, and the rail dual-purpose switching chassis comprises a chassis frame which is symmetrically arranged along a longitudinal center line, a walking wheel group which comprises five groups of walking wheels and is sequentially arranged from front to back along the longitudinal direction of the chassis frame and is composed of front rail auxiliary wheels, front universal wheels, driving wheels, rear universal wheels and rear rail auxiliary wheels, and a modular quick-change interface which is arranged on a top plate of the chassis frame. The application is provided with the driving wheels with coaxial large and small rings and five groups of wheel group layouts, relies on geometric matching to realize passive switching of the road surface mode and the rail mode, does not need to additionally arrange a switching execution mechanism, simplifies the overall structure and reduces control complexity.

Description

Technical Field

[0001] This application relates to the field of agricultural equipment and special vehicle chassis technology, and in particular to a dual-purpose road and rail switching chassis and its working method. Background Technology

[0002] With the rapid development of facility agriculture and precision agriculture, the demand for automated operation equipment in orchards, greenhouses, and other similar settings is increasing daily. In these settings, operating routes are typically fixed and narrow, and traditional wheeled vehicles suffer from problems such as large turning radii and poor maneuverability between rows. While purely rail-based equipment offers high positioning accuracy and stable operation, it cannot flexibly move outside the rails, limiting its applicability. Therefore, a "road-rail dual-purpose" chassis that combines road and rail driving capabilities has become an ideal solution to these challenges.

[0003] Taking a typical Venlo-type multi-span greenhouse as an example, a single greenhouse covers an area of ​​approximately 30 mu (about 2 hectares), with an east-west orientation as the main direction. The central land area inside the greenhouse is arranged in an east-west direction, and cut flowers (such as roses) are planted along both sides of the central road in a north-south direction, using a substrate planting method. Tracks are laid between each row (arranged in a north-south direction), with a track spacing of approximately 40cm-60cm.

[0004] The heating pipes laid on the ground also serve as the robot's walking track, achieving "one track for two purposes"—heating the flowers in winter while also acting as the chassis's running track. The central road surface is flush with the track (connected by a stepped transition), and the track is about 20cm off the ground after it is installed. The ground surface is cement.

[0005] Currently, all field management operations in this type of greenhouse are performed manually. The main field management tasks include spraying pesticides, fertilizing, inspection, pruning, leaf removal, and flower and fruit thinning. Workers spray pesticides row by row in the high-temperature, enclosed greenhouse environment, with pesticides coming into direct contact with their bodies, posing extremely high occupational health risks. At the same time, manual work is inefficient, labor-intensive, and operates in harsh conditions. This situation clearly demonstrates the urgent need to develop automated field management chassis equipment suitable for this type of greenhouse environment. Summary of the Invention

[0006] To solve or partially solve the problems existing in related technologies, this application provides a dual-purpose road and rail switching chassis and its working method.

[0007] This application provides a dual-purpose track-road switching chassis for use with a greenhouse track 14. The track 14 is laid along the inter-row track surface 15, and the end of the track 14 is mounted on the central road surface 13, with the inter-row track surface 15 being lower than the central road surface 13. The dual-purpose track-road switching chassis includes: Chassis frame 1 is arranged symmetrically along the longitudinal centerline; The walking wheel set includes five sets of walking wheels, which are arranged in the longitudinal direction of the chassis frame 1 from front to back as follows: front track auxiliary wheel 2, front swivel wheel 3, drive wheel 4, rear swivel wheel 5, and rear track auxiliary wheel 6. A modular quick-change interface is provided on the top plate of the chassis frame 1; The drive wheel 4 includes a small wheel rim 401 and a large wheel rim 402 rigidly fixed coaxially to the same drive shaft. The small wheel rim 401 is located on the inner side for traveling on the top surface of the track 14, and the large wheel rim 402 is located on the outer side for traveling in road surface mode. The inner side of the large wheel rim 402 forms a limiting fit with the side of the track 14 in track mode. The radius of the large wheel rim 402 is larger than the radius of the small wheel rim 401, and the difference between the radius of the large wheel rim 402 and the radius of the small wheel rim 401 is equal to the height of the top of the track 14 from the center road surface 13. The matching allows the chassis to passively switch between road mode and track mode through a stepped transition; the circumferential surfaces of the front track auxiliary wheel 2 and the rear track auxiliary wheel 6 are arc-shaped structures that match the track 14, and the outer arc-shaped edges of the front track auxiliary wheel 2 and the rear track auxiliary wheel 6 are locked onto the outside of the track 14 for centering and guiding the chassis. Each track auxiliary wheel only bears lateral force in a single direction; the front omnidirectional wheel 3 and the rear omnidirectional wheel 5 are passive omnidirectional wheels, which bear weight and provide steering capability on the ground in road mode, and are suspended in the air in track mode.

[0008] Optionally, in some embodiments, a left drive motor 403 and a right drive motor 404 are respectively connected to the left and right drive wheels 4. The left drive motor 403 drives the left drive wheel 4, and the right drive motor 404 drives the right drive wheel 4. Differential steering of the chassis is achieved by controlling the speed difference between the left and right drive motors. When the two drive motors are at the same speed and in the same direction, the vehicle travels in a straight line. When the two drive motors are at the same speed and in opposite directions, the vehicle can turn left or right on the spot.

[0009] Optionally, in some embodiments, the drive wheel 4 is flexibly connected to the chassis frame 1 via an elastic suspension device 11; the drive shaft of the drive wheel 4 is elastically supported on the chassis frame 1 via the elastic suspension device 11, so that the drive wheel 4 can generate a certain vertical displacement relative to the chassis frame 1. The elastic suspension device 11 includes a chassis connecting frame 115 bolted to the bottom of the chassis frame 1. A fixed seat 114 is connected to the lower part of the chassis connecting frame 115. One end of the fixed seat 114 is hinged to one end of the chassis connecting frame 115 via a fixed connecting shaft 112. A vertical guide sleeve 116 is provided at the other end of the fixed seat 114. A vertical groove is provided on the vertical guide sleeve 116. A sliding connecting shaft 113 is slidably arranged in the vertical groove. The chassis connecting frame 115 and the vertical guide sleeve 116 are slidably connected via the sliding connecting shaft 113. A spring 111 is provided inside the vertical guide sleeve 116. The upper end of the spring 111 is fixedly connected to the chassis connecting frame 115, and the lower end is fixedly connected to the inner wall of the vertical guide sleeve 116. The drive shaft of the drive wheel 4 is mounted on the fixed seat 114. In road mode, the elastic suspension device 11 keeps the large wheel rim 402 in constant elastic contact with the ground, ensuring close contact between the drive wheel 4 and the ground; in track mode, the elastic suspension device 11 keeps the small wheel rim 401 in constant elastic contact with the top surface of the track 14, ensuring good contact between the drive wheel 4 and the track 14.

[0010] Optionally, in some solutions, the modular quick-switch interface includes: The conical pin positioning mechanism 7 uses a conical surface fit to achieve precise positioning between the upper module and the chassis frame 1, realizing the fixing and release of the upper module. The conical pin positioning mechanism 7 includes a locking pin 701 and a locking seat 702. The locking pin 701 is fixed on the bottom plate 121 of the upper working module, and the locking seat 702 is rigidly installed on the top plate 122 of the chassis. Four locking seats 702 are arranged in a rectangular layout on the top surface of the bottom plate of the chassis frame 1. The locking pin 701 moves downward with the upper module. The conical surface of the pin first enters the conical hole of the locking seat 702 to complete the conical surface centering positioning. Rotating the upper operating head of the locking pin 701 activates the cam-ball locking structure inside the pin, realizing the axial locking of the locking pin 701 and the locking seat 702, pressing and fixing the bottom plate 121 of the upper module to the top plate 122 of the chassis. Rotating the locking pin 701 in the opposite direction can release the lock, and the locking pin 701 can be disengaged from the locking seat 702, realizing the separation of the module. The aviation connector 8 is used to simultaneously complete mechanical and electrical docking when the upper module lands on the chassis frame 1. The aviation connector 8 transmits CANopen bus communication signals, RJ45 network cable communication signals, and 48V and 24V power signals.

[0011] Optionally, in some solutions, a navigation and positioning system is also provided on the chassis frame 1. The navigation and positioning system includes a three-dimensional lidar 9 disposed on the front and rear sides of the chassis frame 1 and an inertial measurement unit (IMU) disposed inside the chassis frame 1. The three-dimensional lidar 9 and the inertial measurement unit (IMU) perform multi-sensor fusion positioning to obtain the real-time pose information of the chassis in the greenhouse environment. The chassis frame 1 has pre-stored coordinate information of track calibration points and entry points for multiple tracks. The track calibration points are reference points for posture calibration after the chassis frame 1 arrives. The entry points are located in front of the track calibration points and are the precise entry positions for passive track mounting.

[0012] Optionally, in some solutions, flower-repelling devices 10 are also provided on the front and rear sides of the chassis frame 1. The two sets of flower-repelling devices 10 are located in front of the front track auxiliary wheel 2 and behind the rear track auxiliary wheel 6, respectively. The flower-repelling devices 10 extend from the end of the chassis frame 1 to the outside of the vehicle body. They are non-powered passive deflecting components. Their installation position avoids the locking point 7 and electrical connection point 8 on the chassis top plate, and can be disassembled and maintained independently. When the equipment is in operation, the flower-repelling devices 10 can push the flower branches on both sides outward to prevent the flower branches from rubbing and getting tangled with each walking wheel set, thus protecting the crops from damage.

[0013] A method for operating a dual-purpose (railway and road) switching chassis includes the following steps: During the driving phase of the central road surface 13: the front swivel wheel 3 and the rear swivel wheel 5 are on the ground to bear weight and provide steering ability, the large wheel rim 402 of the drive wheel 4 is on the ground to provide driving force, and the front track auxiliary wheel 2 and the rear track auxiliary wheel 6 are suspended in the air. Upon reaching the starting point of track 14: at the starting point of track 14, the road surface is flush with the top surface of track 14 and there is a stepped transition; the large wheel rim 402 crosses the edge of the step, the small wheel rim 401 falls onto the top surface of track 14, and the vehicle load is gradually borne by the track system; the front track auxiliary wheel 2 and the rear track auxiliary wheel 6 are engaged with the outside of track 14 to form centering guidance; the front omnidirectional wheel 3 and the rear omnidirectional wheel 5 are suspended in the air, completing the passive switching from road surface mode to track mode; During the travel phase of track 14: the front track auxiliary wheel 2, drive wheel 4 and rear track auxiliary wheel 6 are on the track and bear the load. The small wheel rim 401 of the drive wheel 4 rolls on the top surface of the track to provide driving force. The inner side of the large wheel rim 402 is against the side of the track to provide lateral restraint. The front track auxiliary wheel 2 and rear track auxiliary wheel 6 provide centering guidance. The front universal wheel 3 and rear universal wheel 5 are suspended in the air. When the vehicle reaches the derailment point: the large wheel rim 402 contacts the ground. As the chassis moves forward, the large wheel rim 402 fully touches the ground and bears the weight. The small wheel rim 401 detaches from the top surface of the track. The front track auxiliary wheel 2 and the rear track auxiliary wheel 6 detach from the side restraint of the track 14. The front swivel wheel 3 and the rear swivel wheel 5 touch the ground and bear the weight, restoring the vehicle to its road driving state.

[0014] Optionally, in some schemes, the track 14 is a heating pipe in a flower greenhouse, the heating pipe is laid along the direction of the planting row, and the track spacing is 40cm~60cm; the chassis is equipped with different field management modules that travel and operate on the planting row track, the field management modules include a spraying module, a fertilization module, an inspection and monitoring module, a pruning module, a leaf removal module or a flower and fruit thinning module.

[0015] Optionally, in some schemes, during the driving phase of the inter-row track surface 15, the chassis obtains real-time pose information through the fusion positioning of the three-dimensional lidar 9 and IMU, and autonomously navigates to the track calibration point of the target track 14; after reaching the track calibration point, pose calibration is performed to correct lateral deviation, longitudinal deviation and heading angle errors; after completing the pose calibration, it continues to drive to the entry point, and after reaching the entry point, the upper track switching step is performed.

[0016] The technical solution provided in this application may include the following beneficial effects: This application utilizes a drive wheel with coaxially arranged large and small rims, along with a five-set wheel layout, to achieve passive switching between road and rail modes through geometric matching. This eliminates the need for additional switching actuators, simplifying the overall structure and reducing control complexity. The rail auxiliary wheels enable unidirectional centering guidance of the chassis, while the passive omnidirectional wheels automatically achieve ground bearing or suspension under different working conditions. This balances the steering flexibility of road travel with the guiding stability of rail travel, making it suitable for greenhouse operations where road and rail coexist, thus improving the chassis's operational adaptability and reliability.

[0017] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0018] The above and other objects, features and advantages of this application will become more apparent from the more detailed description of exemplary embodiments thereof in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments thereof.

[0019] Figure 1 It is a diagram showing the layout of the tracks inside the greenhouse; Figure 2 This application provides a three-dimensional structural schematic diagram of a dual-purpose (road and rail) switching chassis. Figure 3 This application's embodiment shows a three-dimensional structural diagram of a dual-purpose (road and rail) switching chassis from another angle; Figure 4 This is a cross-sectional view of the drive wheel shown in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of the tapered pin positioning mechanism shown in the embodiments of this application; Figure 6 This is a schematic cross-sectional view of the taper pin positioning mechanism shown in the embodiments of this application; Figure 7 This is a schematic diagram of the structure of the elastic suspension device shown in the embodiments of this application; Figure 8-9 This is a schematic diagram illustrating the working principle of the navigation, positioning, and orbital guidance system shown in the embodiments of this application.

[0020] Figure label: 1-Chassis frame, 2-Front track auxiliary wheel, 3-Front swivel wheel, 4-Drive wheel, 401-Small wheel rim, 402-Large wheel rim, 403-Left drive motor, 404-Right drive motor, 5-Rear swivel wheel, 6-Rear track auxiliary wheel, 7-Cone pin positioning mechanism, 701-Locking pin, 702-Locking seat, 8-Aviation plug, 9-3D laser radar, 10-Pulling device, 11-Elastic suspension device, 111-Spring, 112-Fixed connecting shaft, 113-Sliding connecting shaft, 114-Fixed seat, 115-Chassis connecting frame, 116-Vertical guide sleeve, 121-Upper structure base plate, 122-Chassis structure top plate, 13-Central road surface, 14-Rail, 15-Inter-row track surface. Detailed Implementation

[0021] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make this application more thorough and complete, and to fully convey the scope of this application to those skilled in the art.

[0022] It should be understood that although the terms "first," "second," "third," etc., may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0023] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0024] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0025] Example 1 Referring to the attached diagram, the dual-purpose track-road switching chassis is used in conjunction with the greenhouse track 14. The track 14 is laid along the inter-row track surface 15, and the end of the track 14 is supported on the central road surface 13, with the inter-row track surface 15 being lower than the central road surface 13. The dual-purpose track-road switching chassis includes: Chassis frame 1 is arranged symmetrically along the longitudinal centerline; The walking wheel set includes five sets of walking wheels, which are arranged in the longitudinal direction of the chassis frame 1 from front to back as follows: front track auxiliary wheel 2, front swivel wheel 3, drive wheel 4, rear swivel wheel 5, and rear track auxiliary wheel 6. A modular quick-change interface is provided on the top plate of the chassis frame 1; The drive wheel 4 includes a small wheel rim 401 and a large wheel rim 402 rigidly fixed coaxially to the same drive shaft. The small wheel rim 401 is located on the inner side for traveling on the top surface of the track 14, and the large wheel rim 402 is located on the outer side for traveling in road surface mode. The inner side of the large wheel rim 402 forms a limiting fit with the side of the track 14 in track mode. The radius of the large wheel rim 402 is larger than the radius of the small wheel rim 401, and the difference between the radius of the large wheel rim 402 and the radius of the small wheel rim 401 is equal to the height of the top of the track 14 from the center road surface 13. The matching allows the chassis to passively switch between road mode and track mode through a stepped transition; the circumferential surfaces of the front track auxiliary wheel 2 and the rear track auxiliary wheel 6 are arc-shaped structures that match the track 14, and the outer arc-shaped edges of the front track auxiliary wheel 2 and the rear track auxiliary wheel 6 are locked onto the outside of the track 14 for centering and guiding the chassis. Each track auxiliary wheel only bears lateral force in a single direction; the front omnidirectional wheel 3 and the rear omnidirectional wheel 5 are passive omnidirectional wheels, which bear weight and provide steering capability on the ground in road mode, and are suspended in the air in track mode.

[0026] The front track auxiliary wheel 2 and rear track auxiliary wheel 6 on the left side of the chassis frame 1 bear the lateral force from right to left, and the front track auxiliary wheel 2 and rear track auxiliary wheel 6 on the right side of the chassis frame 1 bear the lateral force from left to right; the track auxiliary wheels adopt single-row angular contact ball bearings, and the single-row angular contact ball bearings bear axial loads in a single direction.

[0027] The front swivel casters 3 and rear swivel casters 5 only bear weight on the ground and provide omnidirectional steering capability in road mode; in track mode, since the small wheel rim 401 of the drive wheel 4 sits on the top surface of the track 14, the vehicle body is raised to the height of the track 14, and the front swivel casters 3 and rear swivel casters 5 are suspended in the air with a gap between them and the top surface of the track 14, so no additional retraction mechanism is required.

[0028] The track 14 is a greenhouse heating pipe, which serves as both a heating pipe and a travel track; the track 14 is suspended in the air, and the spacing between the tracks 14 is 40cm to 60cm; in the track area, the road surface is sunken by 15cm to 25cm relative to the top surface of the track 14.

[0029] In this embodiment, a left drive motor 403 and a right drive motor 404 are respectively connected to the left and right drive wheels 4. The left drive motor 403 drives the left drive wheel 4, and the right drive motor 404 drives the right drive wheel 4. Differential steering of the chassis is achieved by controlling the speed difference between the left and right drive motors. When the two drive motors are at the same speed and in the same direction, the vehicle travels in a straight line. When the two drive motors are at the same speed and in opposite directions, the vehicle can turn left or right on the spot.

[0030] In some implementations, the difference in radius between the large wheel rim 402 and the small wheel rim 401 is slightly greater than the installation height of the track 14 (i.e., the height difference between the top surface of the track and the descending section of the road surface) to ensure a smooth transition of the drive wheel 4 between the two modes. Here, "slightly greater than" means that the radius difference is larger than the track installation height by a reasonable margin (3-8 mm) to compensate for machining errors and wear.

[0031] The structure of the track auxiliary wheel is similar to that of a train wheel. The key feature is that the track auxiliary wheel is positioned on the outside of track 14, with its rim surface engaging with the outer surface of the track, providing centering and guidance. The track auxiliary wheel uses a single-row angular contact ball bearing, a type of bearing naturally suited to withstand axial (lateral) loads in a single direction, exhibiting low friction and high precision, meeting the high-precision requirements of track guidance. The track auxiliary wheel has a fixed installation position and lacks lateral adjustment capability, meaning it does not support track gauge adjustment. Because this invention employs a fixed wheel gauge design with coaxial double-rim drive wheels, the wheel gauge of the track auxiliary wheel strictly matches the wheel gauge of the drive wheel 4, allowing for adaptation to standard tracks without additional adjustment. The wheel gauge of the left and right track auxiliary wheels (i.e., the inner distance between the left and right wheels) matches the outer spacing of the track, enabling the track auxiliary wheel to engage with the outer side of track 14 to form a guiding fit.

[0032] The casters are purely passive. In road mode, the casters bear weight and provide omnidirectional steering capability, giving the chassis flexible steering performance. In track mode, the casters are suspended and do not participate in weight-bearing or guidance. The suspension of the casters is automatically achieved by the overall wheel assembly height layout of the chassis—when the small wheel rim 401 of the drive wheel 4 sits on the top surface of the track 14, a natural gap exists between the caster and the top surface of the track 14, thus achieving suspension without the need for an additional retraction mechanism.

[0033] Example 2 Based on Embodiment 1, the drive wheel 4 is flexibly connected to the chassis frame 1 through the elastic suspension device 11; the drive shaft of the drive wheel 4 is elastically supported on the chassis frame 1 through the elastic suspension device 11, so that the drive wheel 4 can generate a certain vertical displacement relative to the chassis frame 1. The elastic suspension device 11 includes a chassis connecting frame 115 bolted to the bottom of the chassis frame 1. A fixed seat 114 is connected to the lower part of the chassis connecting frame 115. One end of the fixed seat 114 is hinged to one end of the chassis connecting frame 115 via a fixed connecting shaft 112. A vertical guide sleeve 116 is provided at the other end of the fixed seat 114. A vertical groove is provided on the vertical guide sleeve 116. A sliding connecting shaft 113 is slidably arranged in the vertical groove. The chassis connecting frame 115 and the vertical guide sleeve 116 are slidably connected via the sliding connecting shaft 113. A spring 111 is provided inside the vertical guide sleeve 116. The upper end of the spring 111 is fixedly connected to the chassis connecting frame 115, and the lower end is fixedly connected to the inner wall of the vertical guide sleeve 116. The drive shaft of the drive wheel 4 is mounted on the fixed seat 114. In road mode, the elastic suspension device 11 keeps the large wheel rim 402 in constant elastic contact with the ground, ensuring close contact between the drive wheel 4 and the ground; in track mode, the elastic suspension device 11 keeps the small wheel rim 401 in constant elastic contact with the top surface of the track 14, ensuring good contact between the drive wheel 4 and the track 14.

[0034] Specifically, spring 111 is a helical compression spring, which, together with the guide mechanism, restricts the drive wheel 4 to move only vertically, preventing lateral deviation. The stiffness of spring 111 is selected according to the total weight of the chassis and the working conditions, so that the drive wheel 4 has an appropriate pre-compression when static, and can effectively absorb the impact of uneven road or track surfaces under dynamic conditions.

[0035] In road mode, the preload of spring 111 keeps the large wheel rim 402 in close contact with the ground, preventing wheel slippage and slippage caused by bumps, and ensuring reliable transmission of driving force. In track mode, spring 111 keeps the small wheel rim 401 elastically pressed against the top surface of the track, adapting to minor height deviations between track joints and support points, and ensuring stable driving. It effectively isolates the impact vibrations of the road surface and track from being transmitted to the chassis frame 1 and the upper module, protecting the mounted precision electronic equipment and operating mechanisms, and improving the service life and operation quality of the equipment.

[0036] Example 3 Based on Example 1, the modular quick-switch interface includes: The conical pin positioning mechanism 7 uses a conical surface fit to achieve precise positioning between the upper module and the chassis frame 1, realizing the fixing and release of the upper module. The conical pin positioning mechanism 7 includes a locking pin 701 and a locking seat 702. The locking pin 701 is fixed on the bottom plate 121 of the upper working module, and the locking seat 702 is rigidly installed on the top plate 122 of the chassis. Four locking seats 702 are arranged in a rectangular layout on the top surface of the bottom plate of the chassis frame 1. The locking pin 701 moves downward with the upper module. The conical surface of the pin first enters the conical hole of the locking seat 702 to complete the conical surface centering positioning. Rotating the upper operating head of the locking pin 701 activates the cam-ball locking structure inside the pin, realizing the axial locking of the locking pin 701 and the locking seat 702, pressing and fixing the bottom plate 121 of the upper module to the top plate 122 of the chassis. Rotating the locking pin 701 in the opposite direction can release the lock, and the locking pin 701 can be disengaged from the locking seat 702, realizing the separation of the module. The aviation connector 8 is used to simultaneously complete mechanical and electrical docking when the upper module lands on the chassis frame 1. The aviation connector 8 transmits CANopen bus communication signals, RJ45 network cable communication signals, and 48V and 24V power signals.

[0037] When the upper module is lowered onto the chassis base plate, the conical pin automatically aligns and positions itself, the quick-locking mechanism automatically locks, and the aviation plug 8 automatically engages. When the upper module needs to be replaced, simply unlock the locking mechanism, pull out the aviation plug 8, and lift the upper module.

[0038] Replacement time: The entire mechanical-electrical integrated replacement can be completed within 1 to 2 minutes.

[0039] Compatible upper-level modules include, but are not limited to: spraying modules, fertilization modules, inspection and monitoring modules, pruning modules, leaf removal modules, flower and fruit thinning modules, and transport hopper modules, as well as other field management operation devices.

[0040] Example 4 Based on Embodiment 1, a navigation and positioning system is also provided on the chassis frame 1. The navigation and positioning system includes a three-dimensional lidar 9 disposed on the front and rear sides of the chassis frame 1 and an inertial measurement unit (IMU) disposed inside the chassis frame 1. The three-dimensional lidar 9 and the inertial measurement unit (IMU) perform multi-sensor fusion positioning to obtain the real-time pose information of the chassis in the greenhouse environment. The chassis frame 1 has pre-stored coordinate information of track calibration points and entry points for multiple tracks. The track calibration points are reference points for posture calibration after the chassis frame 1 arrives. The entry points are located in front of the track calibration points and are the precise entry positions for passive track mounting.

[0041] Sensor configuration: Two 3D LiDARs 9 are installed at the front and rear of the chassis respectively, scanning in different directions to achieve all-round perception of the environmental characteristics inside the greenhouse; the IMU is installed near the center of gravity of the chassis to measure the angular velocity and acceleration information of the chassis in real time.

[0042] Fusion positioning principle: The 3D LiDAR 9 provides absolute position information by matching the characteristics of the greenhouse environment (such as fixed structures such as the frame, columns, and tracks), while the IMU provides high-frequency angular velocity and acceleration information. The two are complemented and fused through error state Kalman filtering (ESKF) to output the real-time pose information of the chassis in the greenhouse environment (including lateral yaw, longitudinal yaw, and heading angle), with positioning accuracy reaching the centimeter level.

[0043] Critical waypoint pre-calibration: In a greenhouse environment, two critical waypoints are pre-calibrated for each track: Track calibration point: Located at a certain distance in front of the entrance of target track 14. After the chassis navigation reaches this point, it uses fused positioning information to complete the attitude calibration - correcting the lateral deviation, longitudinal deviation and heading angle error, so that the chassis is accurately aligned with the track direction.

[0044] The entry point is the precise entry point located in front of track 14 and at the track entrance. After the chassis continues to travel from the track 14 to the entry point, it will perform a passive track entry operation.

[0045] Navigation process: The chassis autonomously navigates on the road surface using LiDAR + IMU fusion positioning → sequentially travels to the track calibration point of the target track (completes pose calibration) → continues to travel to the entry point → performs passive track mounting at the entry point.

[0046] The track switching process itself is purely mechanical and passive, requiring no sensor intervention. The navigation and positioning system ensures that the chassis arrives at the entry point with the correct lateral, longitudinal, and yaw angles before track insertion, thus meeting the positional accuracy requirements of passive track insertion. A 3D LiDAR 9+IMU fusion positioning scheme provides centimeter-level positional accuracy for the chassis within the greenhouse. By pre-calibrating the track calibration points and entry points of each track, the chassis arrives at the entry position with the correct lateral and yaw angles, solving the positional accuracy requirements of passive track insertion—the fusion positioning ensures that the pre-track position meets the geometric conditions for passive switching, enabling reliable passive track insertion.

[0047] In this embodiment, flower-repelling devices 10 are also provided on the front and rear sides of the chassis frame 1. The two sets of flower-repelling devices 10 are located in front of the front track auxiliary wheel 2 and behind the rear track auxiliary wheel 6, respectively. The flower-repelling devices 10 extend from the end of the chassis frame 1 to the outside of the vehicle body. They are non-powered passive deflecting components. Their installation position avoids the locking point 7 and electrical connection point 8 on the chassis top plate, and can be disassembled and maintained independently. When the equipment is in operation, the flower-repelling devices 10 can push the flower branches on both sides outward to prevent the flower branches from rubbing and getting tangled with each walking wheel set, thus protecting the crops from damage.

[0048] Example 5 Based on Example 4, a working method for a dual-purpose (road and rail) switching chassis includes the following steps: During the driving phase of the central road surface 13: the front swivel wheel 3 and the rear swivel wheel 5 are on the ground to bear weight and provide steering ability, the large wheel rim 402 of the drive wheel 4 is on the ground to provide driving force, and the front track auxiliary wheel 2 and the rear track auxiliary wheel 6 are suspended in the air. Upon reaching the starting point of track 14: at the starting point of track 14, the road surface is flush with the top surface of track 14 and there is a stepped transition; the large wheel rim 402 crosses the edge of the step, the small wheel rim 401 falls onto the top surface of track 14, and the vehicle load is gradually borne by the track system; the front track auxiliary wheel 2 and the rear track auxiliary wheel 6 are engaged with the outside of track 14 to form centering guidance; the front omnidirectional wheel 3 and the rear omnidirectional wheel 5 are suspended in the air, completing the passive switching from road surface mode to track mode; During the travel phase of track 14: the front track auxiliary wheel 2, drive wheel 4 and rear track auxiliary wheel 6 are on the track and bear the load. The small wheel rim 401 of the drive wheel 4 rolls on the top surface of the track to provide driving force. The inner side of the large wheel rim 402 is against the side of the track to provide lateral restraint. The front track auxiliary wheel 2 and rear track auxiliary wheel 6 provide centering guidance. The front universal wheel 3 and rear universal wheel 5 are suspended in the air. When the vehicle reaches the derailment point: the large wheel rim 402 contacts the ground. As the chassis moves forward, the large wheel rim 402 fully touches the ground and bears the weight. The small wheel rim 401 detaches from the top surface of the track. The front track auxiliary wheel 2 and the rear track auxiliary wheel 6 detach from the side restraint of the track 14. The front swivel wheel 3 and the rear swivel wheel 5 touch the ground and bear the weight, restoring the vehicle to its road driving state.

[0049] In the above-rail switching step, the chassis switching from road surface mode to track mode is completed passively by the mechanical structure. There is no need for sensors to identify the track position, no need for the control system to issue switching commands, and no need for additional actuators to operate. The switching is automatically achieved by relying on the geometric matching relationship between the radius difference between the large wheel rim 402 and the small wheel rim 401 and the height difference between the track and the road surface.

[0050] In the track travel state, the chassis is supported by three points on the track: the front track auxiliary wheel 2, the drive wheel 4, and the rear track auxiliary wheel 6. The drive wheel 4 is located in the center between the front track auxiliary wheel 2 and the rear track auxiliary wheel 6, and is the main load-bearing and driving point.

[0051] In this embodiment, the track 14 is a heating pipe in a flower greenhouse. The heating pipe is laid along the planting row direction with a track spacing of 40cm to 60cm. The chassis is equipped with different field management modules that travel and operate on the planting row track. The field management modules include a spraying module, a fertilization module, an inspection and monitoring module, a pruning module, a leaf removal module, or a flower and fruit thinning module.

[0052] In this embodiment, during the driving phase of the inter-row track surface 15, the chassis obtains real-time pose information through the fusion positioning of the three-dimensional lidar 9 and IMU, and autonomously navigates to the track calibration point of the target track 14; after reaching the track calibration point, pose calibration is performed to correct lateral deviation, longitudinal deviation and heading angle errors; after completing the pose calibration, the chassis continues to drive to the entry point, and after reaching the entry point, the upper track switching step is executed.

[0053] Track 14 is suspended in mid-air. In the central road section 13, the road surface is flush with the top surface of track 14, and the two are connected by a stepped transition. When the chassis enters the track area, the road surface sinks 20cm relative to track 14, so that the chassis body is completely supported by the track system.

[0054] A stepped transition refers to a clear step surface between the center road surface 13 and the top surface of the track 14. When the chassis passes over this step surface: Upper track direction: The large wheel rim 402 of the drive wheel 4 first drops slightly, and then the small wheel rim 401 falls to the top surface of the track 14, realizing a natural switch from road surface mode to track mode.

[0055] Derailment direction: The large wheel rim 402 of the drive wheel 4 flips upward onto the road surface, and the small wheel rim 401 then detaches from the top surface of the track 14, achieving a natural switch from track mode to road surface mode.

[0056] Key design parameters: The difference in radius between the large wheel rim 402 and the small wheel rim 401 is slightly greater than the road surface depression height (track installation height) to ensure: The small wheel 401 can reliably fall onto the top surface of the track 14; The large wheel rim 402 will not interfere with the top surface of the track 14; The chassis will not tilt or be impacted significantly during the transition.

[0057] The chassis adopts a dual-motor independent drive scheme: A left drive motor 403 is installed on the left side of the chassis to drive the left drive wheel 4; A right drive motor 404 is installed on the right side of the chassis to drive the right drive wheel 4. Each motor is a three-phase brushless motor with U, V and W three-phase windings; The steering control employs a differential steering method: steering is achieved by controlling the speed difference between the left and right motors, eliminating the need for an additional steering mechanism. When both motors travel at the same speed and in the same direction, the chassis travels in a straight line; when there is a speed difference between the two motors, the chassis steers; when the two motors travel at the same speed but in opposite directions, the chassis can steer left or right in place.

[0058] Fusion positioning principle: The 3D LiDAR 9 provides absolute position observations by matching known environmental features within the greenhouse (positions of steel frame columns, linear characteristics of tracks, etc.). Its positioning accuracy is affected by the richness of environmental features and radar measurement noise, resulting in a relatively low update frequency (50Hz). The IMU provides high-frequency (200Hz) pose recursion through integrated angular velocity and acceleration, but suffers from cumulative drift. The two are fused using an extended Kalman filter (EKF): the IMU recursive result is used as the predicted value, and the LiDAR environmental feature matching result is used as the observed value for correction, thus obtaining a real-time pose output with both high accuracy and high frequency.

[0059] Calibration and function of track calibration points: The calibration points of each track 14 are pre-calibrated during the system deployment phase through teaching or offline measurement, recording their two-dimensional coordinates (x, y) and desired heading angle θ in the greenhouse global coordinate system. The calibration points are located at a certain distance in front of the track entrance (preferably 1-3m), and the selection principle is that the location can clearly perceive sufficient environmental features for lidar positioning, while the path between the location and the track entrance is unobstructed.

[0060] After the chassis reaches the calibration point, the fusion positioning system outputs the current actual pose and compares it with the expected pose during calibration, calculating the lateral deviation (Δx), longitudinal deviation (Δy), and heading angle deviation (Δθ). The control system adjusts the chassis attitude according to the deviations, enabling the chassis to complete pose calibration at the calibration point.

[0061] Calibration and function of the entry point: The entry point is located in front of the track calibration point, at the track entrance, and is also pre-calibrated during the system deployment phase. The position of the entry point corresponds to the precise location where the small wheel rim 401 of the drive wheel 4 is about to contact the edge of the stepped transition, i.e., the starting point of the passive upper rail.

[0062] The distance from the calibration point to the entry point is relatively short (1-3m). The chassis travels in a straight line in the calibrated position during this section. When it reaches the entry point, the chassis's lateral deviation and heading angle errors have been controlled within the range allowed by the passive upper rail (lateral deviation error ≤ ±5mm, heading angle error ≤ ±1°), ensuring that the small wheel rim 401 of the drive wheel 4 can reliably fall onto the top surface of the rail and that the rail auxiliary wheel can smoothly engage with the outer side of the rail.

[0063] Detailed steps of the navigation process: (a) The chassis completes the derailment switch of the current working line, returns to the center road surface 13, and enters the road driving mode.

[0064] (b) The control system determines the next target planting row based on the current work plan and loads the coordinates of the track calibration point and entry point of that row.

[0065] (c) The chassis obtains real-time pose through dual three-dimensional lidar 9+IMU fusion positioning, and the control system plans the path from the current position to the target track calibration point for autonomous navigation.

[0066] (d) After reaching the orbit calibration point, perform pose calibration: compare the current actual pose with the desired pose, and correct the lateral, longitudinal, and heading angle errors to the allowable range through differential drive.

[0067] (e) After the position calibration is completed, the chassis travels in a straight line to the entry point with the calibrated position.

[0068] (f) After reaching the entry point, the chassis continues to move forward and performs passive track switching. This process is completed passively by the mechanical structure (coaxial dual wheel drive wheel 4 + stepped transition + track auxiliary wheel) without the need for sensor intervention. The task of the navigation and positioning system ends here.

[0069] Key Note: In this embodiment, the sensors (LiDAR + IMU) are only used during the road navigation phase to ensure the chassis reaches the entry point with precise orientation. The upper rail switching process itself is purely mechanical and passive; the sensors do not participate in upper rail control.

[0070] Example 6 Specific applications in flower greenhouses: This embodiment describes the specific application of the above-mentioned dual-purpose track and road chassis in the Venlo-type flower greenhouse.

[0071] Greenhouse Layout: The greenhouse is a Venlo-type multi-span greenhouse, with each shed covering approximately 30 acres, primarily oriented east-west. The central land area is centrally located in an east-west direction, forming a concrete central road. Cut flowers (roses / Chinese roses) are planted along both sides of the central road in a north-south direction using substrate planting. Tracks are laid between each row, oriented north-south, with a track spacing of approximately 75cm. The tracks are suspended, with the track surface approximately 20cm off the ground after installation. The central road surface and the top surface of the tracks are connected by a stepped transition, with the road surface and track top surface flush at the junction.

[0072] The "dual-purpose track" structure: the track also serves as the carrier for laying heating pipes in winter. The heating pipes are laid along the track direction below or beside the track, and hot water or hot air is introduced to heat the greenhouse in winter. The track itself serves as the chassis's running track, realizing the sharing of heating and movement functions, significantly reducing the cost of repeated investment in greenhouse infrastructure.

[0073] Workflow: Road driving and navigation positioning phase: The chassis travels on the central concrete road surface in road mode (large wheel rims 402 ground drive, omnidirectional wheels ground bearing weight and steering, auxiliary wheels suspended). The chassis obtains real-time pose information through the fusion positioning of two 3D LiDARs 9 and IMU, autonomously navigates to the track calibration point corresponding to the target planting row, and completes pose calibration (correcting lateral yaw, longitudinal yaw and heading angle errors) upon arrival; then it continues to travel to the entry point.

[0074] Rail switching phase: After the chassis reaches the rail entry point, it autonomously completes the passive rail switching through a stepped transition—the large wheel rim 402 crosses the edge of the step, the small wheel rim 401 falls to the top surface of the rail, the omnidirectional wheels are suspended in the air, and the rail auxiliary wheels are engaged with the outside of the rail to form centering guidance. The rail switching process is purely mechanical and passive, without the need for sensor intervention.

[0075] Track operation phase: The chassis travels north-south along the planting rows in track mode, carrying different superstructure modules to perform corresponding field management operations.

[0076] Derailment return phase: After the operation is completed, the chassis returns to the center road surface through derailment switching - the large wheel rim 402 touches the ground, the small wheel rim 401 is removed from the track, the auxiliary wheel is released from restraint, and the swivel wheel touches the ground to bear the weight.

[0077] Move to the next row: The chassis travels on the center road to the track entrance corresponding to the next planting row, and repeats steps 2-4.

[0078] Practical application scenarios of modular superstructures: The chassis can be quickly connected to various field management superstructure modules through modular quick-change interfaces, covering all field management operation needs of flower greenhouses: The above modules can be replaced within 1 to 2 minutes through the chassis's tapered pin positioning, quick locking, and aviation plug 8's mechanical-electrical integrated quick-change interface.

[0079] To quantify the beneficial effects of the present invention, the following comparison of key performance indicators of the chassis of this embodiment with those of the prior art is conducted: The electrical equipment mentioned above without a specified model number is all existing equipment and will not be described in detail here.

[0080] Finally, it should be noted that in this document, relationships such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "include," "contain," or any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0081] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A dual-purpose track and road switching chassis, used in conjunction with a greenhouse track (14), wherein the track (14) is laid along the inter-row track surface (15), the end of the track (14) is mounted on the central road surface (13), and the inter-row track surface (15) is lower than the central road surface (13), characterized in that, include: The chassis frame (1) is arranged symmetrically along the longitudinal centerline; The walking wheel set includes five sets of walking wheels, which are arranged in the longitudinal direction of the chassis frame (1) from front to back as follows: front track auxiliary wheel (2), front omnidirectional wheel (3), drive wheel (4), rear omnidirectional wheel (5), and rear track auxiliary wheel (6). A modular quick-change interface is provided on the top plate of the chassis frame (1); The drive wheel (4) includes a small wheel rim (401) and a large wheel rim (402) rigidly fixed on the same drive shaft. The small wheel rim (401) is located on the inner side for driving on the top surface of the track (14), and the large wheel rim (402) is located on the outer side for driving in road mode. The inner side of the large wheel rim (402) forms a limiting fit with the side of the track (14) in track mode. The radius of the large wheel rim (402) is larger than the radius of the small wheel rim (401), and the difference between the radius of the large wheel rim (402) and the radius of the small wheel rim (401) is equal to the distance from the top of the track (14) to the center road surface (1). 3) The heights are matched, so that the chassis can achieve passive switching between road mode and track mode through a stepped transition; the circumferential surfaces of the front track auxiliary wheel (2) and the rear track auxiliary wheel (6) are arc-shaped structures that match the track (14), and the outer arc-shaped sides of the front track auxiliary wheel (2) and the rear track auxiliary wheel (6) are placed on the outside of the track (14) for centering and guiding the chassis. Each track auxiliary wheel only bears lateral force in a single direction; the front universal wheel (3) and the rear universal wheel (5) are passive universal wheels, which bear weight and provide steering ability in road mode, and are suspended in track mode.

2. The dual-purpose track and road switching chassis according to claim 1, characterized in that: A left drive motor (403) and a right drive motor (404) are respectively connected to the left and right drive wheels (4). The left drive motor (403) drives the left drive wheel (4), and the right drive motor (404) drives the right drive wheel (4). Differential steering of the chassis is achieved by controlling the speed difference between the left and right drive motors. When the two drive motors are at the same speed and in the same direction, the chassis travels in a straight line. When the two drive motors are at the same speed and in opposite directions, the chassis can turn left or right in place.

3. The dual-purpose switching chassis for both road and rail use according to claim 2, characterized in that: The drive wheel (4) is flexibly connected to the chassis frame (1) through the elastic suspension device (11); the drive shaft of the drive wheel (4) is elastically supported on the chassis frame (1) through the elastic suspension device (11), so that the drive wheel (4) can generate a certain displacement in the vertical direction relative to the chassis frame (1). The elastic suspension device (11) includes a chassis connecting frame (115) bolted to the bottom of the chassis frame (1). A fixed seat (114) is connected to the lower part of the chassis connecting frame (115). One end of the fixed seat (114) is hinged to one end of the chassis connecting frame (115) via a fixed connecting shaft (112). A vertical guide sleeve (116) is provided at the other end of the fixed seat (114). A vertical groove is provided on the vertical guide sleeve (116). A sliding connecting shaft (113) is slidably arranged in the vertical groove. The chassis connecting frame (115) and the vertical guide sleeve (116) are slidably connected through the sliding connecting shaft (113). A spring (111) is arranged in the vertical guide sleeve (116). The upper end of the spring (111) is fixedly connected to the chassis connecting frame (115), and the lower end is fixedly connected to the inner wall of the vertical guide sleeve (116). The drive shaft of the drive wheel (4) is mounted on the fixed seat (114). In road mode, the elastic suspension device (11) keeps the large wheel rim (402) pressed against the ground at all times, ensuring close contact between the drive wheel (4) and the ground; in track mode, the elastic suspension device (11) keeps the small wheel rim (401) pressed against the top surface of the track (14) at all times, ensuring good contact between the drive wheel (4) and the track (14).

4. The dual-purpose (railway and road) switching chassis according to claim 3, characterized in that, The modular quick-switch interface includes: The conical pin positioning mechanism (7) uses a conical surface fit to achieve precise positioning between the upper module and the chassis frame (1), realizing the fixing and release of the upper module. The conical pin positioning mechanism (7) includes a locking pin (701) and a locking seat (702). The locking pin (701) is fixed on the bottom plate (121) of the upper working module, and the locking seat (702) is rigidly installed on the top plate (122) of the chassis. The four locking seats (702) are arranged in a rectangular layout on the top surface of the bottom plate of the chassis frame (1); the locking pin ( 701) Following the downward movement of the upper module, the conical surface of the pin is first inserted into the conical hole of the locking seat (702) to complete the conical surface centering and positioning. Rotating the upper operating head of the locking pin (701) causes the cam-ball locking structure inside the pin to move, thereby axially locking the locking pin (701) and the locking seat (702), pressing and fixing the bottom plate (121) of the upper module onto the top plate (122) of the chassis. Reverse rotation of the locking pin (701) can release the lock, and the locking pin (701) can be dislodged upward from the locking seat (702) to achieve module separation. The aviation connector (8) is used to simultaneously complete mechanical and electrical docking when the upper module lands on the chassis frame (1). The aviation connector (8) transmits CANopen bus communication signals, RJ45 network cable communication signals and 48V and 24V power signals.

5. The dual-purpose track and road switching chassis according to any one of claims 1-4, characterized in that: The chassis frame (1) is also equipped with a navigation and positioning system. The navigation and positioning system includes a three-dimensional lidar (9) set on the front and rear sides of the chassis frame (1) and an inertial measurement unit (IMU) set inside the chassis frame (1). The three-dimensional lidar (9) and the inertial measurement unit (IMU) perform multi-sensor fusion positioning to obtain the real-time pose information of the chassis in the greenhouse environment. The chassis frame (1) has pre-stored coordinate information of track calibration points and entry points for multiple tracks. The track calibration points are reference points for posture calibration after the chassis frame (1) arrives. The entry points are located in front of the track calibration points and are the precise entry points for passively mounting the tracks.

6. The dual-purpose (railway and road) switching chassis according to claim 5, characterized in that: The front and rear sides of the chassis frame (1) are also provided with flower-pulling devices (10). The two sets of flower-pulling devices (10) are located in front of the front rail auxiliary wheel (2) and behind the rear rail auxiliary wheel (6), respectively. The flower-pulling device (10) extends from the end of the chassis frame (1) to the outside of the vehicle body. It is a passive blocking component without power. Its installation position avoids the locking point (7) and electrical connection point (8) on the top plate of the chassis. It can be disassembled and maintained independently. When the equipment is in operation, the flower-pulling device (10) can push the flower branches on both sides outward to avoid the flower branches from rubbing and getting tangled with each walking wheel group, and protect the crops from damage.

7. The working method of the dual-purpose track and road switching chassis according to claim 6, characterized in that, Includes the following steps: During the driving phase of the central road surface (13): the front omnidirectional wheel (3) and the rear omnidirectional wheel (5) are on the ground to bear weight and provide steering ability, the large wheel rim (402) of the drive wheel (4) is on the ground to provide driving force, and the front track auxiliary wheel (2) and the rear track auxiliary wheel (6) are suspended in the air; When traveling to the starting point of track (14): the road surface at the starting point of track (14) is flush with the top surface of track (14) and there is a stepped transition; the large wheel (402) crosses the edge of the step, the small wheel (401) falls onto the top surface of track (14), and the vehicle load is gradually borne by the track system; the front track auxiliary wheel (2) and the rear track auxiliary wheel (6) are inserted into the outside of track (14) to form a centering guide; the front universal wheel (3) and the rear universal wheel (5) are suspended in the air, completing the passive switching from road surface mode to track mode; During the track (14) travel phase: the front track auxiliary wheel (2), drive wheel (4) and rear track auxiliary wheel (6) bear weight on the track. The small wheel rim (401) of the drive wheel (4) rolls on the top surface of the track to provide driving force. The inner side of the large wheel rim (402) is attached to the side of the track to provide lateral restraint. The front track auxiliary wheel (2) and rear track auxiliary wheel (6) provide centering guidance. The front universal wheel (3) and rear universal wheel (5) are suspended in the air. When the vehicle reaches the derailment point: the large wheel rim (402) contacts the ground. As the chassis moves forward, the large wheel rim (402) fully touches the ground and bears the weight. The small wheel rim (401) leaves the top surface of the track. The front track auxiliary wheel (2) and the rear track auxiliary wheel (6) leave the side constraint of the track (14). The front universal wheel (3) and the rear universal wheel (5) touch the ground and bear the weight, restoring the road driving state.

8. The working method of the dual-purpose track and road switching chassis according to claim 7, characterized in that: The track (14) is a heating pipe in the flower greenhouse. The heating pipe is laid along the direction of the planting row and the track spacing is 40cm~60cm. The chassis is equipped with different field management modules that travel and operate on the planting row track. The field management modules include a spraying module, a fertilization module, an inspection and monitoring module, a pruning module, a leaf removal module, or a flower and fruit thinning module.

9. The working method of the dual-purpose track and road switching chassis according to claim 8, characterized in that: During the driving phase of the inter-row track surface (15), the chassis obtains real-time pose information through the fusion positioning of the three-dimensional lidar (9) and IMU, and autonomously navigates to the track calibration point of the target track (14). After reaching the orbit calibration point, position calibration is performed to correct lateral yaw, longitudinal yaw, and heading angle errors. After completing the position calibration, the vehicle continues to travel to the entry point. Upon reaching the entry point, the above-ground track switching steps are executed.

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