High-precision automatic docking mechanism applied to complex scene

Abstract

The invention provides a high-precision automatic docking mechanism applied to a complex scene, the high-precision automatic docking mechanism comprises a vertical docking mechanism and an omnidirectional docking mechanism, the vertical docking mechanism comprises a vertical male head and a first female head, the omnidirectional docking mechanism comprises an omnidirectional male head and a second female head, the vertical male head and the omnidirectional male head are installed on a right AGV, and the second female head is installed on a right AGV. The first female head and the second female head are mounted on the left AGV, and cross pairing is formed during butt joint: the vertical male head of the right AGV is inserted into the first female head of the left AGV; the omnidirectional male head of the right AGV is inserted into the second female head of the left AGV, the vertical male head provides a one-dimensional swing freedom degree around the X axis and an elastic floating freedom degree in the Z direction, bears a vertical load and compensates relative pitching and vertical displacement between the two AGVs caused by ground fluctuation, and the omnidirectional male head provides a multi-directional swing freedom degree so that the relative pitching and vertical displacement between the two AGVs can be adjusted. Relative yaw, roll, and thus coupled in-plane displacements are compensated for.

Description

Technical Field

[0001] This invention belongs to the field of automated guided vehicles (AGVs) and automated logistics technology, specifically a high-precision automatic docking mechanism for use in complex scenarios. Background Technology

[0002] In automated logistics and flexible manufacturing systems, the collaborative transfer of large and heavy materials by multiple AGVs has become a key means of improving efficiency. This typically requires two or more AGVs to achieve a rigid mechanical connection during movement, forming a unified motion platform. Currently, the mainstream mechanical connection (docking) solutions between AGVs mainly include:

[0003] Rigid pin / flange docking: This type of solution requires that after the two AGVs stop, the pin holes or flanges on their docking surfaces must be highly precisely aligned (usually requiring millimeter-level or even sub-millimeter-level positioning accuracy). The docking process relies on the precision positioning drive system of the AGV body to actively adjust and eliminate positional deviations. Its drawbacks are: (1) It has extremely stringent requirements for the navigation system, motion control accuracy and ground flatness. Any slight stopping error or ground undulation will lead to docking failure or generate huge assembly stress; (2) Even if docking is successful, in the subsequent coordinated movement process, due to slight unevenness of the road surface or deformation of the vehicle body, the rigid connection will constrain the deformation inside the vehicle body structure, generating harmful static indeterminate internal forces (commonly known as "stress"), which will lead to abnormal wear of the drive wheels, deformation of the frame or fatigue damage of the connecting parts in the long term, seriously affecting the reliability of the system and the life of the equipment.

[0004] Flexible docking with single-direction compensation: To reduce alignment requirements, some solutions introduce connectors with a certain degree of flexibility, such as swing hinges, linear slides, or simple spring buffer mechanisms in a single direction. The drawback is that the compensation degree of freedom is limited (usually only compensating for deviations in one or two directions), making it unable to adapt to the complex three-dimensional relative pose changes that may occur between AGVs (including three translations and three rotations, a total of six degrees of freedom). Under complex road conditions, it is still very easy to generate constraints, leading to internal stress or connection instability.

[0005] In summary, existing technologies struggle to achieve a balance between high reliability, high fault tolerance, reasonable cost, and complete elimination of internal stress, thus hindering the large-scale application of AGV team collaboration technology in complex industrial scenarios. Summary of the Invention

[0006] This invention proposes a high-precision automatic docking mechanism for complex scenarios to overcome the contradiction between the existing AGV docking mechanisms' stringent requirements for parking and road conditions and their inability to achieve full-degree-of-freedom stress-free compensation.

[0007] The technical solution to achieve the purpose of this invention is as follows: a high-precision automatic docking mechanism for complex scenarios, comprising: a vertical docking mechanism and an omnidirectional docking mechanism. The vertical docking mechanism includes a vertical male connector and a first female connector, and the omnidirectional docking mechanism includes an omnidirectional male connector and a second female connector. The vertical male connector and the omnidirectional male connector are installed on the right AGV, and the first female connector and the second female connector are installed on the left AGV. During docking, a cross pairing is formed: the vertical male connector of the right AGV is inserted into the first female connector of the left AGV; the omnidirectional male connector of the right AGV is inserted into the second female connector of the left AGV. The vertical male connector provides a one-dimensional swing degree of freedom around the X-axis and an elastic floating degree of freedom in the Z-axis, bears the vertical load, and compensates for the relative pitch and vertical displacement between the two AGVs caused by ground undulations. The omnidirectional male connector compensates for relative yaw, roll, and the resulting in-plane displacement by providing multi-directional swing degrees of freedom.

[0008] Preferably, the vertical male connector includes a first ball head, a first ball head seat, a T-shaped swing arm, a first position sensor, a bearing assembly, and a first bottom reset assembly. The first ball head includes a screw and a ball head disposed at one end of the screw. The first ball head seat has a threaded hole at its center, which is fastened to the other end of the screw of the first ball head. The main body of the T-shaped swing arm is T-shaped. The vertical rod of the T-shaped swing arm is connected to the first ball head seat, and the two ends of the horizontal rod are connected to the left AGV body through the bearing assembly. The two ends of the horizontal rod are mounted to the left AGV body through the bearing assembly, so that the entire vertical male connector swings ±15° to ±20° in the vertical plane around the horizontal axis to compensate for pitch angle and vertical displacement. The first position sensor is disposed on the side of the first ball head seat near the first female connector and is used to detect the proximity state to the female connector and provide a positioning trigger signal. The first bottom reset assembly is used to provide vertical adaptive reset capability.

[0009] Compared with the prior art, the significant advantages of this invention are:

[0010] (1) Significantly improved docking success rate and environmental adaptability: The docking process reduces the accuracy requirements for AGV positioning from the traditional millimeter level to the centimeter level, significantly lowering the stringent requirements on the AGV navigation system, drive control system, and ground flatness. Even in complex scenarios with bumps, slopes, or accumulated positioning errors, it can still maintain an extremely high docking success rate.

[0011] (2) Completely eliminates internal stress in the connection and extends equipment life: The heterogeneous floating system can effectively absorb and compensate for relative positional deviations, making the AGVs act like a flexible whole after connection, and can adapt to road undulations during movement. This fundamentally eliminates the "stress" phenomenon, eliminates static indeterminate internal forces in the vehicle body structure, drive wheel system and connecting components, greatly reduces mechanical wear and fatigue damage, and significantly extends the service life of AGVs and related equipment.

[0012] (3) The system has high reliability and strong robustness: The core compensation function relies on the passive floating of the mechanical structure, which has relatively low requirements for the real-time performance and accuracy of the control system. Active control is only used for the final locking action, and the logic is simple and reliable.

[0013] (4) Structural optimization and obvious overall cost advantages: Compared with the use of two sets of omnidirectional mechanisms or active attitude adjustment platforms, the asymmetric design of the present invention reduces one set of complex omnidirectional swing mechanism while ensuring performance, and adopts more standardized components, making the overall structure simpler and effectively controlling manufacturing and maintenance costs.

[0014] (5) Intelligent interface and expandability: The optional force sensor provides the system with force sensing capability, enabling force control during docking and monitoring of the operating status, providing a data foundation for predictive maintenance and more advanced collaborative control.

[0015] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0016] Figure 1 This is a diagram showing the overall layout of the docking mechanism of the present invention installed on the left and right AGVs.

[0017] Figure 2 This is a structural diagram of the vertical male connector.

[0018] Figure 3 This is a sectional view of the vertical male connector (100).

[0019] Figure 4 The outline of the female head (200).

[0020] Figure 5 This is a structural cross-sectional view (closed state) of the female head (200).

[0021] Figure 6 This is a structural cross-sectional view of the female head (200) (open state).

[0022] Figure 7 This is a structural diagram of the omnidirectional male connector (300).

[0023] Figure 8 This is a structural cross-sectional view of the omnidirectional male connector (300). Detailed Implementation

[0024] A high-precision automatic docking mechanism for complex scenarios enables automatic, reliable, high-precision, and stress-free mechanical connection between two AGVs under conditions of non-ideal road surfaces (with undulations and slopes) and large positioning errors (centimeter-level). It can passively or actively absorb and compensate for multi-dimensional relative posture deviations (including linear and angular displacements in three directions) that may occur when the two AGVs dock, ensuring that no harmful static indeterminate internal forces are generated at the connection point and inside the AGV body during the connection moment and subsequent coordinated movement. This achieves the goal of "flexible tolerance docking and rigid and stable connection", thereby significantly improving the system's robustness, success rate, and equipment lifespan.

[0025] A high-precision automatic docking mechanism for complex scenarios adopts an asymmetric, heterogeneous collaborative floating hinge system, specifically consisting of a vertical docking mechanism and an omnidirectional docking mechanism installed on the first AGV (hereinafter referred to as the left AGV) and the second AGV (hereinafter referred to as the right AGV). The two parts are complementary in terms of spatial arrangement and function.

[0026] The vertical docking mechanism is used to provide the main vertical load and compensate for swaying about a specific axis. Specifically, it includes a vertical male connector (100) and a first female connector (200). The omnidirectional docking mechanism, as a floating end, includes an omnidirectional male connector (300) and a second female connector (200'). The vertical male connector (100) and the omnidirectional male connector (300) are installed on the right AGV, and the first female connector (200) and the second female connector (200') are installed on the left AGV. During docking, a cross pairing is formed: the vertical male connector (100) of the right AGV is inserted into the first female connector (200) of the left AGV; the omnidirectional male connector (300) of the right AGV is inserted into the second female connector (200') of the left AGV.

[0027] Core collaborative compensation principle: The vertical male connector (100) provides a one-dimensional swing degree of freedom around the X-axis and an elastic floating degree of freedom in the Z-axis, mainly bearing the vertical load and compensating for the relative pitch and vertical displacement between the two AGVs caused by ground undulations. The omnidirectional male connector (300) provides multi-directional swing degrees of freedom (which can be decomposed into rotation around the Y-axis and Z-axis) through the fisheye bearing, mainly compensating for relative yaw, roll, and the resulting in-plane displacement. Together, they form a heterogeneous collaborative floating hinge system, which can passively absorb and compensate for possible relative pose deviations between the two AGVs without relying on complex active control. During docking, the female connector's tapered hole first achieves a large-tolerance "coarse guide," and then the motor-driven clamping block achieves a "fine grip" lock, forming a high-rigidity ball joint connection. In subsequent collaborative movements, this floating system continues to work, ensuring that the connection point can adaptively move slightly with changes in the road surface, fundamentally avoiding the generation of statically unstable internal forces.

[0028] The vertical male connector (100) includes a first ball head (101), a first ball head seat (102), a T-shaped swing arm (103), a first position sensor (105), a bearing assembly (110), and a first bottom reset assembly (120). The first ball head (101) includes a screw and a ball head disposed at one end of the screw. The first ball head seat (102) has a threaded hole in the center, which is fastened to the other end of the screw of the first ball head (101). The main body of the T-shaped swing arm (103) is T-shaped. The vertical rod of the T-shaped swing arm (103) is connected to the first ball joint (102), and the two ends of the horizontal rod are installed on the left AGV body through the bearing assembly (110), so that the entire vertical male head can swing ±15° to ±20° around the horizontal axis (X-axis) in the vertical plane to compensate for the pitch angle and vertical displacement. The first position sensor (105) is set on the side of the first ball joint (102) close to the first female head (200) to detect the proximity state with the female head and provide a positioning trigger signal.

[0029] The bearing assembly (110) is key to achieving one-dimensional oscillation. The bearing assembly (110) includes two bearings (111), which are angular contact ball bearings or tapered roller bearings. The two bearings (111) are pressed into the shafts at both ends of the crossbar of the T-shaped swing arm (103). The inner ring of the bearing is axially fixed by a lock nut (114). The outer ring of the bearing is fixed to the left AGV body by a bearing housing (112). The bearing end cap (113) is installed on the bearing housing (112). An O-ring (115) is installed between the bearing end cap (113) and the bearing housing (112), together with the skeleton oil seal (116) on the other side of the bearing housing (112), to achieve the grease sealing function. This design allows the entire vertical male connector (100) to swing ±15° to ±20° around the crossbar axis (defined as the X-axis) in the vertical plane (i.e., the YZ plane), mainly to compensate for the relative pitch and vertical (Z-axis) displacement between the two AGVs.

[0030] The first bottom reset assembly (120) provides vertical adaptive reset capability. Specifically, it includes a linear motion element (121) mounted on the AGV body via a flange. The linear motion element (121) is a linear bearing, a guide shaft (122) passing through the interior of the linear motion element (121), and a compression spring (123) fitted onto the guide shaft (122) and positioned between the T-shaped swing arm (103) and the flange face of the linear motion element (121). The top of the guide shaft (122) contacts the swing arm, and the bottom is limited by double nuts (124). When the male end is subjected to vertical force, the compressible spring moves downwards, and resets under spring force after the external force disappears, effectively absorbing vertical impact and displacement.

[0031] In a further embodiment, a force sensor (104) is provided at the connection between the first ball joint (102) and the T-shaped swing arm (103) to monitor the axial and radial forces transmitted during the docking process and operation in real time, and the signal is fed back to the control system to achieve compliant control and overload protection.

[0032] Specifically, the first ball head (101) is made of high-strength alloy steel, and its surface is hardened and wear-resistant. Its ball diameter can be designed from Φ20mm to Φ300mm depending on the load.

[0033] In a further embodiment, the first female head (200) includes a female head mounting guide seat (201), a mounting frame, a clamping assembly (210), a drive unit (220), and a limit detection unit;

[0034] The mounting frame is composed of two parallel thick steel plates as female mounting plates (202), which are firmly connected to both sides of the guide seat (201) by bolts to form the main load-bearing frame.

[0035] The clamping assembly (210) is an actuator that achieves "precise gripping" and rigid locking, specifically including: two clamping blocks (211), two screw nuts (212) with opposite suspension directions, a guide mechanism (213), a forward and reverse rotating screw (214), and a screw limit block (215).

[0036] Two clamping blocks (211) are symmetrically arranged in the vertical direction. The clamping blocks (211) are connected to the slider (213a) of the guide mechanism (213). Two screw nuts (212) with opposite suspension directions are rigidly connected to the two clamping blocks (211) by screws. The two screw nuts (212) with opposite suspension directions include screw nut 212a and screw nut 212b. The guide mechanism (213) adopts a linear guide rail slider pair. The guide rail (213b) is fixedly installed on the inner side of the female head mounting plate (202), and the slider (213a) is connected to the clamping blocks (211).

[0037] The forward and reverse screw (214) has a left-hand thread at one end and a right-hand thread at the other end. The forward and reverse screw (214) (accuracy grade C7) is passed through two screw nuts.

[0038] The lead screw limiting block (215) is installed at the bottom of the forward and reverse turn lead screw (214) by screws to achieve axial limiting of the lead screw (214).

[0039] The drive unit (220) includes a servo / stepper motor (221) and a reducer (222) (preferably a planetary gear reducer with a speed ratio of 10-100) connected to the motor output shaft. The reducer (222) is fixed to a U-shaped reducer mounting plate (223) via its mounting flange, and the two wings of the reducer mounting plate (223) are connected to the upper ends of two female head mounting plates (202). The output shaft of the reducer (222) is connected to one end of a forward and reverse rotary lead screw (214) via a coupling (224).

[0040] The limiting detection unit includes a female head limiting block (203), two bottom limiting plates (204), two second position sensors (205), and a sensor sensing plate (207). The end of the female head limiting block (203) is a buffer block made of rubber or polyurethane material, which is bolted to a set position inside the female head mounting plate (202) to limit the excessive movement of the first ball head (101) after it is clamped, and at the same time play a role in buffering and shock absorption. The two bottom limiting plates (204) are respectively installed on the bottom of the female head mounting plate (202) to realize the bottom limiting of the clamping assembly. The two second position sensors (205) are installed on the sensor mounting plate (206), which is installed on the female head limiting block (203) to realize the positioning signal feedback function. The sensor sensing plate (207) is installed on the female head mounting guide seat (201) and corresponds to the position of the male head end position sensor (108) to realize the position signal feedback function during docking.

[0041] In a further embodiment, the clamping blocks (211) are made of a wear-resistant material (such as a copper-based alloy), and each clamping block has a hemispherical groove precisely machined on its inner side, with a radius of curvature slightly larger than that of the male ball head to ensure surface contact rather than line contact. A self-lubricating pad can be embedded in the surface of the groove.

[0042] In a further embodiment, the guide mechanism (213) can also be replaced by a “guide sleeve + guide shaft”, with the guide shaft fixed on the mounting plate and the guide sleeve set on the clamping block.

[0043] The omnidirectional docking mechanism, as a floating end, provides multi-dimensional swing freedom to compensate for residual deviations. It includes an omnidirectional male connector (300) and a second female connector (200'). The omnidirectional male connector (300) includes a second ball joint (301), a second ball joint seat (302), a straight rod swing arm (303), a second force sensor (304), a second position sensor (305), a second bottom reset assembly (320), a fisheye bearing assembly, and two side reset assemblies (310). The second ball joint (301) is disposed on the second ball joint seat (302). One end of the straight rod swing arm (303) is connected to the second ball joint seat (302). The second force sensor (304) is disposed at the connection between the straight rod swing arm (303) and the second ball joint seat (302).

[0044] The fisheye bearing assembly is the core component for achieving multi-directional oscillation. Specifically, it includes a fisheye bearing (309) (i.e., a rod end joint bearing), a bearing pin (306), and a U-shaped fisheye bearing housing (308). The fisheye bearing (309) is threaded to the other end of the straight rod swing arm (303). The bearing pin (306) passes through the side plate holes of the U-shaped bearing housing (308) and the inner ring of the fisheye bearing (309), and is secured at its end with a lock nut (307). The U-shaped bearing housing (308) is rigidly mounted on the right AGV body. The use of the fisheye bearing (309) allows the omnidirectional male connector (300) to achieve multi-directional oscillation around its center point within a conical space (typically with a cone angle ≥ ±5°), effectively compensating for the relative yaw angle, roll angle, and small-range lateral (Y-axis) and longitudinal (X-axis) displacements between the two AGVs in the horizontal plane.

[0045] Two side reset assemblies (310) provide lateral adaptive reset capability. Specifically, they include a linear motion element (311) mounted via a flange to a mounting base (315), the linear motion element (311) employing a linear bearing, the mounting base (315) mounted on the AGV body, a guide shaft (312) passing through it, and a compression spring (313) fitted onto the guide shaft, positioned between the straight arm (303) and the flange face of the linear motion element (311). The top of the guide shaft (312) contacts the arm rod, and the end is limited by a double nut (314). When the male end is subjected to lateral force, the compressible spring moves left and right; after the external force disappears, it resets under the spring force, effectively absorbing lateral impact and displacement.

[0046] The innovation of this invention lies in:

[0047] (1) Design of Heterogeneous Collaborative Floating Hinge System: The system innovatively adopts an asymmetric combination of "vertical one-dimensional swing + omnidirectional multi-dimensional swing" instead of two identical omnidirectional mechanisms. The vertical male connector has a simple and robust structure and is dedicated to bearing the main load and compensating for the main deviations (pitch / vertical); the omnidirectional male connector serves as the omnidirectional floating end, compensating for the remaining degrees of freedom. This design achieves the same full degree of freedom compensation effect as the omnidirectional double-joint system with better cost and reliability.

[0048] (2) A three-tiered intelligent docking strategy of "coarse guidance - fine grasp - force sensing":

[0049] Coarse guidance: By utilizing the tapered hole of the female guide seat (201), initial guidance and correction with large tolerance (centimeter level) are achieved at the mechanical level, reducing the dependence on the absolute stopping accuracy of the AGV.

[0050] Precision gripping: The clamping block (211) driven by the servo motor actively grips the male ball joint to form a precise surface contact ball joint pair with good connection rigidity and strong load-bearing capacity.

[0051] (3) Multi-dimensional force monitoring design: The optional integrated force sensors (104, 304) enable real-time force monitoring of the docking process and operating status, providing feedback to the control system, realizing smooth docking, overload protection and preventive maintenance, and improving the level of intelligence and safety.

[0052] (4) Highly modular and interchangeable design: The female connectors (200 and 200') used on the left and right sides have completely identical structures, and the male connector parts are also completely identical. This design greatly simplifies the manufacturing, spare parts management and field maintenance process, and reduces the total life cycle cost.

[0053] Example

[0054] This embodiment uses the docking of two 5-ton AGVs in a warehouse environment as an example for illustration, wherein the diameter of the male ball joint (101, 301) is Φ80mm.

[0055] 1. Specific implementation and assembly of key components

[0056] (1) Machining and assembly of the vertical male connector (100):

[0057] The first ball head (101) is made of 40Cr material. After being turned and ground, it is subjected to heat treatment and surface hard chrome plating.

[0058] The T-shaped swing arm (103) is made of a material with a strength not lower than Q235B. The two shafts used to mount the bearing (111) have a tolerance of js7 to ensure coaxiality. After completion, a heat treatment is performed to obtain good overall mechanical properties.

[0059] A pair of tapered roller bearings (111, model: 32220) are pressed into the shaft of the T-shaped swing arm (103). The inner ring of the bearing is secured by a shaft lock nut (114) and a locking washer. The assembled swing arm assembly is placed into the bearing housing (112), and the outer ring of the bearing is pressed and fixed by the bearing end cap (113). The bearing housing (112) is bolted to the pre-set reinforcing plate of the first AGV body. During installation, it must be ensured that the swing axis (X-axis) is perpendicular to the AGV's forward direction (Y-axis).

[0060] The force sensor (104) (optional, a three-dimensional force sensor is used in this embodiment) is connected between the bottom of the first ball head seat (102) and the top of the vertical rod of the T-shaped swing arm (103) by a high-strength bolt.

[0061] The linear motion element (121) of the first bottom reset assembly (120) is an oil-free bushing with its flange fixed to the vehicle body. The guide shaft (122) passes through the bearing and its top contacts the lower surface of the T-shaped swing arm crossbar. The stiffness of the compression spring (123) is selected based on the load and the expected maximum road surface undulation (e.g., ±20mm) to ensure sufficient reset force without excessive stiffness.

[0062] (2) Assembly of the omnidirectional male connector (300):

[0063] The fisheye bearing (304) is a rod end spherical bearing (e.g., SA type), whose threaded rod end is screwed tightly to one end of the straight rod swing arm (303) and prevented from loosening.

[0064] Place the fisheye bearing (304) into the U-shaped fisheye bearing housing (308), insert the bearing pin (306), and tighten the end with a lock nut (307). The U-shaped bearing housing (308) is rigidly connected to the right AGV body by bolts.

[0065] (3) Assembly of the female connector (200 / 200'):

[0066] The slide rails of the two linear guide rails (213) are precisely installed on the inner sides of the two female mounting plates (202) with hexagon socket bolts to ensure their parallelism.

[0067] Connect the two clamping blocks (211) to the corresponding sliders respectively, and then fix the screw nuts (212a, 212b) with positive and negative threads to the back of the clamping blocks with screws.

[0068] The forward and reverse screws (214) (accuracy grade C7) are passed through two screw nuts, and their bottoms are axially limited by screw limit blocks (215).

[0069] Align the assembled side mounting plates (202) with the female head mounting guide (201) and fasten them with high-strength bolts to form a sturdy overall frame.

[0070] The reducer (222) (in this embodiment, a planetary gear reducer with a speed ratio of 50:1) is fixed to the U-shaped reducer mounting plate (223) via its mounting flange, and then the reducer mounting plate (223) is connected to the top of the two female head mounting plates (202). The servo motor (221) is connected to the input hole of the reducer (222) via a flange, and is connected to the top of the lead screw (214) via a diaphragm coupling (224).

[0071] Manually rotate the lead screw to check whether the two clamping blocks (211) can move smoothly and synchronously towards and away from each other. Adjust the position of the female head limit block (203) so that when the clamping blocks are fully closed, there is a gap of about 1-2mm between it and the male head swing arm that is in the ideal center, which can prevent hard collisions and limit excessive movement.

[0072] 2. Control system integration:

[0073] Each AGV's controller (such as a PLC or dedicated motion controller) is responsible for controlling one female drive motor and one male drive motor (the female drive motor of the opposing AGV) on its own vehicle. The controller receives a "docking ready" command from the AGV's main navigation system and receives feedback signals from position sensors (105, 305) and force sensors (104, 304).

[0074] The control logic flow is as follows:

[0075] Preparation phase: The two AGVs travel to their relative positions according to the instructions. The controller sends an instruction to drive the servo motors (221) on both sides of the female head to rotate at low speed. Combined with the signal feedback from the position sensor 205, the clamping block (211) is opened to the maximum preset opening position.

[0076] Approach and Coarse Guidance Stage: The AGVs travel towards each other at a low speed (e.g., 0.1 m / s). The male ball head gradually enters the tapered guide hole (201) of the opposing female head and automatically centers under the guidance of the tapered surface.

[0077] Contact detection and precision gripping stage: When the male ball head reaches the predetermined depth, its position sensor (105 / 305) aligns with the sensing plate (207) on the female head, sending a positioning signal. Alternatively, the force sensor (104 / 304) detects that the contact force exceeds the threshold. The controller then commands the female head drive motor (221) to reverse, driving the clamping block to close in constant torque mode. The clamping block grips the ball head with appropriate force until the second position sensor (205) reports that the predetermined position has been reached.

[0078] Locking and Confirmation Phase: The motor stops and the brake is energized to maintain the locking force. The controller detects the clamping status signals of both female terminals. Once both confirm "clamping complete," the controller sends a "mechanical docking complete" signal to the AGV main control system. At this point, the two AGVs have mechanically become a single, interconnected platform.

[0079] Operation and monitoring phase: During coordinated movement, force sensors continuously monitor the force at the connection points. If an abnormal impact force is detected (such as exceeding a safety threshold), an alarm can be sent to the AGV main control system, triggering deceleration or emergency stop to ensure safety.

[0080] 3. Detailed description of the work process:

[0081] Typical compensation process: Assuming the left AGV is horizontally stationary, the right drive wheel of the right AGV stops after passing over a pipe or protrusion about 15mm high, resulting in a relative pitch angle (right higher than left) and slight yaw between the two AGVs.

[0082] Docking Phase: The two AGVs slowly approach each other. The ball head of the vertical male connector (100) on the right AGV first inserts into the conical hole of the female connector (200) on the left AGV. Due to the pitch angle, the ball head will abut against the inclined surface of the conical hole. Under the slight thrust of the AGV continuing to slowly approach, the ball head slides along the inclined surface into the bottom of the hole, forcing the T-shaped swing arm (103) of the vertical male connector (100) of the right AGV to swing slightly downward around its bearing axis (X-axis). This process automatically absorbs the initial pitch deviation. At the same time, the ball head of the omnidirectional male connector (300) on the left AGV also enters the conical hole of the female connector (200) on the right AGV. Subsequently, the clamping components of both female connectors act simultaneously, firmly clamping their respective ball heads to form two rigid ball joint connections.

[0083] Coordinated Motion and Floating Compensation Phase: After docking, the two AGVs begin to move forward collaboratively. When the right wheel of the right AGV moves off the protrusion, its body posture returns from tilted to horizontal. During this dynamic process:

[0084] At the right connection point (vertical male head 100 - female head 200): when the right AGV body returns to horizontal, the T-shaped swing arm (103) of its vertical male head (100) swings back to the center position around the X-axis with the assistance of the reset spring (123), compensating for this relative movement.

[0085] At the left connection point (omnidirectional male 300 - female 200'): the omnidirectional male (300) on the right AGV adapts to small changes in the spatial position of the connection point by deflection of its fisheye bearing (304).

[0086] Throughout the process, the floating degrees of freedom of the two connection points work together, allowing the two AGV bodies to move relatively slightly without generating internal constraints within the connection mechanism. The force values ​​monitored by the force sensors are stable, without abrupt peaks, verifying the effectiveness of the stress-free connection.

[0087] 4. Optional and alternative solutions:

[0088] This invention is not limited to the specific embodiments described above. Those skilled in the art can make various modifications without departing from the core design concept of this invention.

[0089] Guide mechanism replacement: In low-cost or heavy-load, low-speed applications, the linear guide (213) of the female head (200) can be replaced by a sliding guide pair consisting of a guide shaft and a graphite copper sleeve.

[0090] Drive method alternative: In scenarios where the clamping force control accuracy is not high, the servo / stepper motor (221) of the female head can be replaced by a DC motor or pneumatic motor with mechanical limit switch and a clutch and brake.

[0091] Sensor simplification: Force sensors (104, 304) are the preferred intelligent configuration, but not essential. For basic functionality, the force sensor can be omitted, relying solely on motor encoder position and current loop feedback for simple clamping control.

[0092] Application Expansion: This docking mechanism is not only suitable for dynamic docking between AGVs, but also for automatic docking and locking of AGVs with fixed charging piles, assembly workstations, and lifting platforms, as well as for rapid rigid connection scenarios between mobile robots and other mobile devices.

[0093] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-precision automatic docking mechanism for use in complex scenarios, characterized in that, include: A vertical docking mechanism and an omnidirectional docking mechanism are provided. The vertical docking mechanism includes a vertical male connector (100) and a first female connector (200). The omnidirectional docking mechanism includes an omnidirectional male connector (300) and a second female connector (200'). The vertical male connector (100) and the omnidirectional male connector (300) are installed on the right AGV, and the first female connector (200) and the second female connector (200') are installed on the left AGV. When docking, they form a cross pairing: the vertical male connector (100) of the right AGV is inserted into the first female connector (200) of the left AGV; the omnidirectional male connector (300) of the right AGV is inserted into the second female connector (200') of the left AGV. The vertical male connector (100) provides a one-dimensional swing degree of freedom around the X-axis and an elastic floating degree of freedom in the Z-axis, bears the vertical load, and compensates for the relative pitch and vertical displacement between the two AGVs caused by ground undulations. The omnidirectional male connector (300) compensates for relative yaw, roll, and the horizontal displacement coupled therefrom by providing multi-directional swing degrees of freedom.

2. The high-precision automatic docking mechanism for complex scenarios according to claim 1, characterized in that, The vertical male connector (100) includes a first ball head (101), a first ball head seat (102), a T-shaped swing arm (103), a first position sensor (105), a bearing assembly (110), and a first bottom reset assembly (120). The first ball head (101) includes a screw and a ball head disposed at one end of the screw. The first ball head seat (102) has a threaded hole in the center, which is fastened to the other end of the screw of the first ball head (101). The main body of the T-shaped swing arm (103) is T-shaped, and the vertical rod of the T-shaped swing arm (103) is connected to the first ball head. The headstock (102) is connected, and the two ends of the horizontal rod are connected to the left AGV body via the bearing assembly (110). The two ends of the horizontal rod are connected to the left AGV body via the bearing assembly (110), so that the entire vertical male head swings ±15° to ±20° in the vertical plane around the horizontal axis to compensate for the pitch angle and vertical displacement. The first position sensor (105) is set on the side of the first ball head (102) close to the first female head (200) to detect the proximity state with the female head and provide a positioning trigger signal. The first bottom reset assembly (120) is used to provide vertical adaptive reset capability.

3. The high-precision automatic docking mechanism for complex scenarios according to claim 2, characterized in that, The bearing assembly (110) includes two bearings (111), which are angular contact ball bearings or tapered roller bearings. The two bearings (111) are pressed into the shafts at both ends of the crossbar of the T-shaped swing arm (103). The inner ring of the bearing is axially fixed by a lock nut (114), and the outer ring of the bearing is fixed to the left AGV body by a bearing seat (112). The bearing end cover (113) is installed on the bearing seat (112). An O-ring (115) is installed between the bearing end cover (113) and the bearing seat (112), and together with the skeleton oil seal (116) on the other side of the bearing seat (112), they achieve the grease sealing function. This design allows the entire vertical male head (100) to swing ±15° to ±20° around the crossbar axis (defined as the X-axis) in the vertical plane (i.e., the YZ plane), mainly to compensate for the relative pitch angle and vertical displacement between the two AGVs.

4. The high-precision automatic docking mechanism for complex scenarios according to claim 2, characterized in that, The first bottom reset assembly (120) includes a linear motion element (121) mounted on the AGV body via a flange. The linear motion element (121) is a linear bearing, a guide shaft (122) passing through the interior of the linear motion element (121), and a compression spring (123) sleeved on the guide shaft (122) and located between the T-shaped swing arm rod (103) and the flange face of the linear motion element (121). The top end of the guide shaft (122) contacts the swing arm rod, and the bottom is limited by a double nut (124).

5. The high-precision automatic docking mechanism for complex scenarios according to claim 1, characterized in that, The first female head (200) includes a female head mounting guide seat (201), a mounting frame, a clamping assembly (210), a drive unit (220), and a limit detection unit; The mounting frame is composed of two parallel thick steel plates as female mounting plates (202), which are firmly connected to both sides of the guide seat (201) by bolts to form the main load-bearing frame; The clamping assembly (210) is an actuating component that achieves "precise gripping" and rigid locking, specifically including: two clamping blocks (211), two screw nuts (212) with opposite suspension directions, a guide mechanism (213), a forward and reverse rotating screw (214), and a screw limit block (215). Two clamping blocks (211) are symmetrically arranged in the vertical direction. The clamping blocks (211) are connected to the slider (213a) of the guide mechanism (213). Two screw nuts (212) with opposite suspension directions are rigidly connected to the two clamping blocks (211) by screws. The two screw nuts (212) with opposite suspension directions include screw nut 212a and screw nut 212b. The guide mechanism (213) adopts a linear guide rail slider pair. The guide rail (213b) is fixedly installed on the inner side of the female head mounting plate (202), and the slider (213a) is connected to the clamping blocks (211). The positive and negative screw (214) has a left-hand thread at one end and a right-hand thread at the other end. The positive and negative screw (214) (accuracy grade C7) is passed through two screw nuts. The lead screw limiting block (215) is installed at the bottom of the forward and reverse rotary lead screw (214) by screws to achieve axial limiting of the forward and reverse rotary lead screw (214); The output shaft of the drive unit (220) is connected to the positive and negative rotary lead screw (214); The limiting detection unit includes a female head limiting block (203), two bottom limiting plates (204), two second position sensors (205), and a sensor sensing plate (207). The end of the female head limiting block (203) is bolted to a set position inside the female head mounting plate (202) to limit the excessive movement of the first ball head (101) after it is clamped, and at the same time to buffer and dampen the shock. The two bottom limiting plates (204) are respectively installed on the bottom of the female head mounting plate (202) to realize the bottom limiting of the clamping assembly. The two second position sensors (205) are installed on the sensor mounting plate (206), which is installed on the female head limiting block (203) to realize the positioning signal feedback function. The sensor sensing plate (207) is installed on the female head mounting guide seat (201) and corresponds to the position of the male head end position sensor (108) to realize the positioning signal feedback function during docking.

6. The high-precision automatic docking mechanism for complex scenarios according to claim 5, characterized in that, The drive unit (220) includes a servo / stepper motor (221) and a reducer (222) connected to the output shaft of the motor. The reducer (222) is fixed on a U-shaped reducer mounting plate (223). The two wings of the reducer mounting plate (223) are connected to the upper ends of two female head mounting plates (202). The output shaft of the reducer (222) is connected to one end of a forward and reverse screw (214) through a coupling (224).

7. The high-precision automatic docking mechanism for complex scenarios according to claim 1, characterized in that, The omnidirectional male connector (300) includes a second ball joint (301), a second ball joint seat (302), a straight rod swing arm (303), a second bottom reset assembly (320), a fisheye bearing assembly, and two side reset assemblies (310). The second ball joint (301) is disposed on the second ball joint seat (302). One end of the straight rod swing arm (303) is connected to the second ball joint seat (302). The fisheye bearing (309) is disposed on the right AGV body and connected to the straight rod swing arm (303). The two side reset assemblies (310) are used to provide lateral adaptive reset capability, and the second bottom reset assembly (320) is used to provide vertical adaptive reset capability.

8. The high-precision automatic docking mechanism for complex scenarios according to claim 7, characterized in that, The two-sided reset assembly (310) includes a linear motion element (311) mounted on the mounting base (315) via a flange. The linear motion element (311) uses a linear bearing. The mounting base (315) is mounted on the AGV body. A guide shaft (312) passes through it. A compression spring (313) is sleeved on the guide shaft and located between the straight arm (303) and the flange face of the linear motion element (311). The top end of the guide shaft (312) contacts the arm rod, and the end is limited by a double nut (314).

9. The high-precision automatic docking mechanism for complex scenarios according to claim 1, characterized in that, The structure of the second female head (200') is the same as that of the first female head (200).

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