A rigid-flexible hybrid parallel docking mechanism

Abstract

The present application belongs to the technical field of shore-to-ship docking mechanism, and particularly relates to a rigid-flexible hybrid parallel docking mechanism, which comprises a fixed platform, a movable platform, three passive elastic branch chains and three driving devices connecting the fixed platform and the movable platform. The three passive elastic branch chains form a 3-RPS parallel structure to constrain the movement of the movable platform along the x-axis and the y-axis and the rotation of the movable platform around the z-axis. The three driving devices are arranged to enable the movable platform to rotate around the x-axis and the y-axis and move along the z-axis under the action of the three driving steel ropes, thereby meeting the actual scene requirements of docking operation. The movable first slider and the pulley assembly are arranged on the movable platform and the fixed platform respectively, so that the values of r and R can be adjusted, the positions of the three driving steel ropes can be changed, and the rigidity of the mechanism can be adjusted to adapt to different load conditions and improve the flexibility and adaptability of the system.

Description

Technical Field

[0001] This invention belongs to the technical field of shore-to-ship docking mechanisms, specifically relating to a rigid-flexible hybrid parallel docking mechanism. Background Technology

[0002] Ports are global trade and transportation hubs, providing crucial infrastructure support for international shipping and logistics systems. Among these, port energy replenishment and liquid cargo loading / unloading are two vital port operational functions, directly impacting port operational efficiency and the smooth operation of ships. Due to the effects of wind, waves, and currents, vessels berthed at port inevitably experience irregular movements in six degrees of freedom: roll, pitch, bow, sway, heave, and so on. While anchoring or the ship's propulsion system can compensate for the ship's sway, pitch, and bow movements, the roll, pitch, and heave require shore-to-ship docking systems for attitude control and motion compensation to ensure the proper functioning of shore-to-ship docking operations for port energy replenishment or liquid cargo loading / unloading.

[0003] Traditional port energy replenishment and liquid cargo loading / unloading shore-to-ship docking typically uses a rigid connection between the loading arm's end flange and the ship's hull flange. This method has the following main problems:

[0004] (1) Since the connection between the loading arm and the hull is rigid, when the hull is affected by external forces such as waves and wind and its position changes, it is difficult to make real-time automatic adjustments to the loading arm to maintain a good docking state. Real-time attitude adjustment is difficult, which increases the difficulty of the operator's work and safety hazards. Moreover, rigid docking will subject the loading arm and the hull to large impact loads. Under long-term use, the docking flange is prone to wear and damage, requiring frequent maintenance and replacement, which increases operating costs.

[0005] (2) Due to the lack of automated adjustment capabilities, loading and unloading operations rely on manual operation of the docking arm and the hull for frequent fine-tuning, which greatly reduces loading and unloading efficiency, increases operation time, and results in low docking efficiency. Summary of the Invention

[0006] In view of this, in order to solve the problems existing in the prior art, the purpose of the present invention is to provide a rigid-flexible hybrid parallel docking mechanism, which has the ability to adjust posture, improve load-bearing capacity and docking efficiency.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A rigid-flexible hybrid parallel docking mechanism, characterized in that it comprises: a fixed platform, a moving platform, and three passive elastic branches connecting the fixed platform and the moving platform. The moving platform is used to dock with an external target platform. Each of the passive elastic branches includes a piston rod and a piston cylinder connected to each other. The upper end of the piston rod is connected to the moving platform through a ball joint, and the lower end of the piston cylinder is rotatably connected to the fixed platform through a rotating joint.

[0009] Three driving devices are arranged alternately with the passive elastic chain. Each driving device includes a first slider, a first slide rail base, a driving cable, a pulley assembly, a second slide rail base, and a motor assembly. The first slide rail base is arranged around the central spokes of the moving platform, and the second slide rail base is arranged around the central spokes of the fixed platform. The first slide rail base is disposed on the lower end surface of the moving platform. The first slider is slidably connected to the first slide rail base. The upper end of the driving cable is connected to the first slider, and the lower end of the driving cable passes through the pulley assembly and is connected to the motor assembly. The second slide rail base is disposed on the fixed platform, and the pulley assembly is slidably connected to the second slide rail base.

[0010] The specific technical effect is as follows: by adopting three passive elastic branches to form a parallel structure of 3-RPS, the movement of the moving platform along the x-axis and y-axis and its rotation around the z-axis are constrained. By setting three drive devices, under the action of three drive cables, the moving platform can realize rotation around the x-axis and y-axis and movement along the z-axis, forming a motion output based on 3-RPS with two rotational and one translational degrees of freedom, to compensate for the ship's own roll, pitch and heave motion under the influence of environmental factors, and meet the actual needs of docking operations.

[0011] Furthermore, the three first sliders have identical structures and are symmetrical about the center of the moving platform, the first slide rail base has identical structures and is symmetrical about the center of the moving platform, and a cable anchor point B is formed at the connection between the driving cable and the first slider. The three cable anchor points B are connected in sequence to form a second triangle, the circumcircle of the second triangle is S2, and the radius of S2 is r. The first slider can move towards or away from the center of the moving platform to change the parameter r, and the range of r is 60mm to 120mm.

[0012] Furthermore, a cable anchor point A is formed at the contact point between the drive cable and the pulley assembly. Three cable anchor points A are connected in sequence to form a first triangle. The circumcircle of the first triangle is S1, and the radius of S1 is R. The pulley end can move towards or away from the center of the fixed platform to change the parameter R. The range of R is 60mm to 120mm. The ratio of r to R is set to a, where a = r / R. The stiffness performance of the rigid-flexible hybrid parallel docking mechanism increases with the increase of a. When a = r / R = 1, the stiffness performance of the rigid-flexible hybrid parallel docking mechanism increases with the increase of the values ​​of r and R.

[0013] The specific technical effect is as follows: by setting a first slider, a first slide rail base, a pulley assembly, and a second slide rail base on a fixed platform and a moving platform respectively, the positions of the first slider and the pulley assembly can be adjusted. By changing the positions of the first slider and the pulley assembly, the values ​​of r and R can be adjusted, thereby changing the positions of the three drive cables, thus realizing the adjustable stiffness of the mechanism to adapt to different load conditions and improve the flexibility and adaptability of the system.

[0014] Furthermore, it also includes: three claw assemblies, all three claw assemblies are disposed on the moving platform, one end of each claw assembly is rotatably connected to the moving platform, and the other end of each claw assembly extends toward the center of the moving platform to clamp the external target platform.

[0015] Furthermore, the three gripper assemblies have identical structures and are symmetrical about the center of the fixed platform. Each gripper assembly includes a clamping gripper, a hydraulic rod, and a hydraulic cylinder. The upper end of the clamping gripper extends toward the center of the moving platform to clamp the external target platform. The middle part of the clamping gripper is rotatably connected to the moving platform. One end of the hydraulic rod is connected to the lower end of the clamping gripper through a cylindrical joint. The hydraulic cylinder is mounted on the lower end face of the moving platform through a third mounting bolt. The other end of the hydraulic rod is connected to the hydraulic cylinder.

[0016] The specific technical effect is as follows: the three gripper components have the same performance and parameters. The hydraulic cylinder pushes the hydraulic rod to move, which in turn pushes the clamping gripper to rotate, so as to clamp the moving platform with the external target platform. One end of the hydraulic rod is connected to the lower end of the clamping gripper through a cylindrical pair. The cylindrical pair maintains a certain space to meet the movement stroke of the hydraulic rod when driving the docking gripper to clamp during the extension and retraction process.

[0017] Furthermore, the three pulley assemblies have the same structure and are symmetrical about the center of the fixed platform. Each pulley assembly includes a pulley device and a second slider. The pulley device is rotatably mounted on the second slider, and the second slider is slidably connected to the second slide rail base. The drive cable passes through the pulley device and is connected to the motor assembly.

[0018] The specific technical effect is that the three pulley assemblies have the same performance and parameters. The second slider slides along the second slide rail base to change the position of the pulley device, thereby changing the value of R. The pulley device is rotatably set on the second slider to adjust the guide orientation so that it is always parallel to the plane where the drive cable is located.

[0019] Furthermore, the three motor assemblies have the same structure and are symmetrical about the center of the fixed platform. Each motor assembly includes an interconnected drive motor and a reducer. The drive motor and the reducer are both mounted on the fixed platform. The lower end of the drive cable passes through the pulley assembly and is connected to the rotating winch of the reducer.

[0020] The specific technical effect is as follows: the three motor components have the same performance and parameters. The drive motor rotates, thereby controlling the rotation of the geared motor and the winch. The lower end of the drive cable is wound on the rotating winch. The rotation of the winch controls the extension and shortening of the drive cable.

[0021] Furthermore, the three ball joints are identical in structure and symmetrical about the center of the fixed platform. Each ball joint includes a ball joint base and a ball head. The ball joint base is disposed on the lower end surface of the moving platform, and the ball head is rotatably connected to the ball joint base. One end of the piston rod is connected to the ball head.

[0022] Furthermore, the passive elastic branch also includes a fixed base and a spring. The fixed base is disposed on the fixed platform, and the spring is fitted onto the outside of the piston rod. The lower end of the spring abuts against the piston cylinder. The rotating pair includes a rotating pair shaft, a rolling bearing, a round nut, and a washer. The rotating pair shaft is disposed at the lower end of the piston cylinder. The rolling bearing, the washer, and the round nut are sequentially fitted onto the rotating pair shaft. The rolling bearing is disposed on the fixed base.

[0023] The specific technical effect is that the three passive elastic branches have the same performance and parameters. They constrain the movement of the moving platform along the x and y axes and the rotation around the z axis through the rotatable connection between the ball head and the ball joint base, the telescopic connection between the piston rod and the piston cylinder, and the rotatable connection between the rotating joint and the fixed base. During the docking process, the spring is always in a compressed state, ensuring that the drive cable is always kept taut.

[0024] Furthermore, a buffer sealing ring is provided on the moving platform.

[0025] The specific technical effect is that the buffer sealing ring plays a role in sealing and buffering the pipeline during docking operations.

[0026] The beneficial effects of this invention are:

[0027] (1) By adopting three passive elastic branches to form a 3-RPS parallel structure, the moving platform is constrained to move along the x-axis and y-axis and rotate around the z-axis. By setting three drive devices, under the action of three drive cables, the moving platform can rotate around the x-axis and y-axis and move along the z-axis, which meets the actual needs of docking operations. The rigid-flexible hybrid design has a greater advantage in ensuring the safety of attitude adjustment during docking.

[0028] (2) By setting movable first slider and pulley assembly on the moving platform and fixed platform respectively, the values ​​of r and R can be adjusted to change the position of the three drive steel cables, thereby realizing the adjustable stiffness of the mechanism to adapt to different load conditions, improve the flexibility and adaptability of the system. This variable mechanism configuration has variable stiffness characteristics, which can optimize the energy absorption and dispersion of the load, reduce the damage to the docking mechanism, and extend the service life of the equipment.

[0029] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0030] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the structure of the present invention;

[0032] Figure 2 yes Figure 1 The main view;

[0033] Figure 3 yes Figure 2 The left view;

[0034] Figure 4 This is a schematic diagram of the passive elastic branch structure of the present invention;

[0035] Figure 5 This is a schematic diagram of the structure of the first slider and the first slide rail base of the present invention;

[0036] Figure 6 This is a schematic diagram of the drive device of the present invention;

[0037] Figure 7 This is a schematic diagram of the fixed platform of the present invention;

[0038] Figure 8 This is a schematic diagram of the structure of the moving platform of the present invention;

[0039] Figure 9 This is a simplified diagram of the mechanism configuration of Embodiment 1 of the present invention;

[0040] Figure 10 This is the stiffness performance diagram of Embodiment 1 of the present invention;

[0041] Figure 11 This is a simplified diagram of the mechanism configuration of Embodiment 2 of the present invention;

[0042] Figure 12 This is the stiffness performance diagram of Embodiment 2 of the present invention;

[0043] Figure 13 This is a simplified diagram of the mechanism configuration of Embodiment 3 of the present invention;

[0044] Figure 14 This is the stiffness performance diagram of Embodiment 3 of the present invention;

[0045] Figure 15 This is a simplified diagram of the mechanism configuration of Embodiment 4 of the present invention;

[0046] Figure 16 This is the stiffness performance diagram of Embodiment 4 of the present invention;

[0047] Figure 17 This is a graph showing the change of the stiffness performance index of the present invention with the r / R value;

[0048] Figure 18 This is a simplified diagram of the mechanism configuration of Embodiment 5 of the present invention;

[0049] Figure 19 This is the stiffness performance diagram of Embodiment 5 of the present invention;

[0050] Figure 20 This is a simplified diagram of the mechanism configuration of Embodiment 6 of the present invention;

[0051] Figure 21 This is the stiffness performance diagram of Embodiment 6 of the present invention;

[0052] Figure 22 This is a simplified diagram of the mechanism configuration of Embodiment 7 of the present invention;

[0053] Figure 23 This is the stiffness performance diagram of Embodiment 7 of the present invention;

[0054] Figure 24 This is a simplified diagram of the mechanism configuration of Embodiment 8 of the present invention;

[0055] Figure 25 This is the stiffness performance diagram of Embodiment 8 of the present invention;

[0056] Figure 26 This is a graph showing the change of the stiffness performance index of the present invention with the value of r = R.

[0057] In the picture:

[0058] 1. Moving platform; 2. Buffer sealing ring; 3. Drive device; 31. Drive cable; 32. Motor assembly; 33. Reducer; 34. Drive motor; 4. First mounting bolt; 5. Second mounting bolt; 6. Pulley assembly; 61. Second slide rail base; 62. Pulley device; 63. Second slider; 7. Fixed platform; 8. Third mounting bolt; 9. Passive elastic support chain; 91. Ball joint base; 92. Ball head; 93. Piston rod; 94. Piston cylinder; 95. Rotary joint; 951. Rotary joint shaft; 952. Rolling bearing; 953. Round nut; 954. Washer; 96. Fixed base; 97. Spring; 101. First slider; 102. First slide rail base; 11. Claw assembly; 111. Clamping gripper; 112. Hydraulic cylinder; 113. Hydraulic rod; 12. First mounting hole; 13. Second mounting hole. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0060] like Figures 1 to 8 As shown, a rigid-flexible hybrid parallel docking mechanism includes: a fixed platform 7, a moving platform 1, and three passive elastic branches 9 connecting the fixed platform 7 and the moving platform 1. The moving platform 1 is used to dock with an external target platform. Each passive elastic branch 9 includes a piston rod 93 and a piston cylinder 94 connected to each other. The upper end of the piston rod 93 is connected to the moving platform 1 through a ball joint, and the lower end of the piston cylinder 94 is rotatably connected to the fixed platform 7 through a rotating joint.

[0061] Three driving devices 3 are arranged alternately with the passive elastic support chain 9. Each driving device 3 includes a first slider 101, a first slide rail base 102, a driving steel cable 31, a pulley assembly 6, a second slide rail base 61, and a motor assembly 32. The first slide rail base 102 is arranged around the central spokes of the moving platform 1, and the second slide rail base 61 is arranged around the central spokes of the fixed platform 7. The first slide rail base 102 is located on the lower end surface of the moving platform 1. The first slider 101 is slidably connected to the first slide rail base 102. The upper end of the driving steel cable 31 is connected to the first slider 101, and the lower end of the driving steel cable 31 passes through the pulley assembly 6 and is connected to the motor assembly 32. The second slide rail base 61 is located on the fixed platform 7, and the pulley assembly 6 is slidably connected to the second slide rail base 61.

[0062] It should be noted that by using three passive elastic branches 9 to form a parallel structure of 3-R (revolute joint), P (prismatic joint), and S (spherical joint), the movement of the moving platform 1 along the x-axis and y-axis, as well as its rotation around the z-axis, is constrained. By setting three drive devices 3, under the action of three drive cables 31, the moving platform 1 can realize rotation around the x-axis and y-axis and movement along the z-axis, forming a motion output based on 3-RPS with two rotational and one translational degrees of freedom. This compensates for the ship's own roll, pitch, and heave motion under the influence of environmental factors, meeting the actual needs of docking operations.

[0063] In this system, the normal direction of the fixed platform 7 is defined as the Z direction, the center of the fixed platform 7 is the origin O of the coordinate system, the center points of the axes of the three revolute joints are connected in sequence to form an equilateral triangle, the plane in which the equilateral triangle is located is the XOY plane, and the XYZ coordinate system is established.

[0064] Three first sliding grooves are provided on the lower end surface of the moving platform 1. The three first sliding grooves have the same structure and are symmetrical about the center of the fixed platform 7. The first slide rail base 102 is installed in the first sliding groove by the first mounting bolt 4.

[0065] The three first sliders 101 have the same structure and are symmetrical about the center of the moving platform 1. The first slide rail base 102 has the same structure and is symmetrical about the center of the moving platform 1. The connection between the driving cable 31 and the first slider 101 forms a cable anchor point B. The three cable anchor points B are connected in sequence to form a second triangle. The circumcircle of the second triangle is S2, and the radius of S2 is r. The first slider 101 can move towards or away from the center of the moving platform 1 to change the parameter r. The range of r is 60mm to 120mm.

[0066] At the contact point between the drive cable 31 and the pulley assembly 6, a cable anchor point A is formed. Three cable anchor points A are connected in sequence to form a first triangle. The circumcircle of the first triangle is S1, and the radius of S1 is R. The pulley end can move towards or away from the center of the fixed platform 7 to change the parameter R. The range of R is 60mm to 120mm. The ratio of r to R is set to a, where a = r / R. The stiffness performance of a rigid-flexible hybrid parallel docking mechanism increases with the increase of a. When a = r / R = 1, the stiffness performance of a rigid-flexible hybrid parallel docking mechanism increases with the increase of the values ​​of r and R.

[0067] It should be noted that by setting the first slider 101, the first slide rail base 102, the pulley assembly 6, and the second slide rail base 61 on the fixed platform 7 and the moving platform 1 respectively, the positions of the first slider 101 and the pulley assembly 6 can be adjusted. By changing the positions of the first slider 101 and the pulley assembly 6, the values ​​of r and R can be adjusted, thereby changing the positions of the three drive cables 31, thus realizing the adjustable stiffness of the mechanism to adapt to different load conditions and improve the flexibility and adaptability of the system. Before docking, the positions of the first slider 101 and the pulley assembly 6 are adjusted so that the first slider 101 is locked relative to the first slide rail base 102 and the pulley assembly 6 is locked relative to the second slide rail base 61. That is, the values ​​of r and R are determined, and the configuration of the rigid-flexible hybrid parallel docking mechanism is determined at this time.

[0068] It also includes: three jaw assemblies 11, all of which are mounted on the moving platform 1. One end of each jaw assembly 11 is rotatably connected to the moving platform 1, and the other end of each jaw assembly 11 extends toward the center of the moving platform 1 to clamp the external target platform.

[0069] The three gripper assemblies 11 have the same structure and are symmetrical about the center of the fixed platform 7. Each gripper assembly 11 includes: a clamping gripper 111, a hydraulic rod 113 and a hydraulic cylinder 112. The upper end of the clamping gripper 111 extends toward the center of the moving platform 1 to clamp the external target platform. The middle part of the clamping gripper is rotatably connected to the moving platform 1. One end of the hydraulic rod 113 is connected to the lower end of the clamping gripper 111 through a cylindrical joint. The hydraulic cylinder 112 is mounted on the lower end face of the moving platform 1 through a third mounting bolt 8. The other end of the hydraulic rod 113 is connected to the hydraulic cylinder 112.

[0070] It should be noted that the three gripper assemblies 11 have identical performance and parameters. The hydraulic cylinder 112 pushes the hydraulic rod 113 to move, thereby pushing the clamping gripper 111 to rotate, so as to clamp the moving platform 1 with the external target platform. One end of the hydraulic rod 113 is connected to the lower end of the clamping gripper 111 through a cylindrical pair. The cylindrical pair maintains a certain space to meet the movement stroke of the hydraulic rod 113 when driving the docking gripper to clamp during the extension and retraction process.

[0071] The gripper assembly 11 is connected to an external signal control device. When the target platform approaches the moving platform 1, the gripper assembly 11 receives a signal from the external signal control device and controls the hydraulic cylinder 112 to start. The hydraulic cylinder 112 pushes the hydraulic rod 113 to move, thereby pushing the clamping gripper 111 to rotate, so as to clamp the moving platform 1 and the target platform. At this time, the docking operation is completed.

[0072] The three pulley assemblies 6 have the same structure and are symmetrical about the center of the fixed platform 7. Each pulley assembly 6 includes a pulley device 62 and a second slider 63. The pulley device 62 is rotatably mounted on the second slider 63. The second slider 63 is slidably connected to the second slide rail base 61. The drive cable 31 passes through the pulley device 62 and is connected to the motor assembly 32.

[0073] It should be noted that the performance and parameters of the three pulley assemblies 6 are exactly the same. The second slider 63 slides along the second slide rail base 61 to change the position of the pulley device 62, thereby changing the value of R. The pulley device 62 is rotatably mounted on the second slider 63 to adjust the guide orientation so that it is always parallel to the plane where the drive cable 31 is located.

[0074] The fixed platform 7 has three second slide grooves. The three second slide grooves have the same structure and are symmetrical about the center of the fixed platform 7. The second slide grooves have several second mounting holes 13. The second slide rail base 61 is installed in the second slide groove through the several second mounting holes 13.

[0075] The three motor assemblies 32 have the same structure and are symmetrical about the center of the fixed platform 7. Each motor assembly 32 includes a drive motor 34 and a reducer 33 connected to each other. The drive motor 34 and the reducer 33 are both set on the fixed platform 7. The lower end of the drive cable 31 passes through the pulley assembly 6 and is connected to the rotating winch of the reducer 33.

[0076] It should be noted that the three motor components 32 have identical performance and parameters. The external microcontroller control system controls the drive motor 34 to rotate, which in turn drives the rotating winch of the reducer 33 to rotate. The lower end of the drive cable 31 is wound around the rotating winch, and the rotation of the winch controls the extension and shortening of the drive cable 31.

[0077] The drive motor 34 and the reducer 33 are mounted on the fixed platform 7 by bolts.

[0078] The three ball joints have the same structure and are symmetrical about the center of the fixed platform 7. Each ball joint includes a ball joint base 91 and a ball head 92. The ball joint base 91 is disposed on the lower end surface of the moving platform 1. The ball head 92 is rotatably connected to the ball joint base 91. One end of the piston rod 93 is connected to the ball head 92.

[0079] The passive elastic support chain 9 also includes a fixed base 96 and a spring 97. The fixed base 96 is set on the fixed platform 7. The spring 97 is fitted on the outside of the piston rod 93. The lower end of the spring 97 abuts against the piston cylinder 94. The rotating pair 95 includes a rotating pair shaft 951, a rolling bearing 952, a round nut 953 and a washer 954. The rotating pair shaft 951 is set at the lower end of the piston cylinder 94. The rolling bearing 952, the washer 954 and the round nut 953 are sequentially fitted on the rotating pair shaft 951. The rolling bearing 952 is set on the fixed base 96.

[0080] It should be noted that the three passive elastic branches 9 have identical performance and parameters. They constrain the movement of the moving platform 1 along the x-axis and y-axis and the rotation around the z-axis through the rotatable connection between the ball head 92 and the ball joint base 91, the telescopic connection between the piston rod 93 and the piston cylinder 94, and the rotatable connection between the rotating joint 95 and the fixed base 96. During the docking process, the spring 97 is always in a compressed state to ensure that the drive cable 31 is always kept taut.

[0081] The ball-type base 91 is mounted on the lower end face of the moving platform 1 by the second mounting bolt 5.

[0082] The fixed platform 7 has three base mounting slots, and each base mounting slot is provided with several first mounting holes 12. The fixed base 96 is installed in the base mounting slot through several first mounting holes 12.

[0083] The rotating pair 95 includes: a rotating pair shaft 951, a rolling bearing 952, a round nut 953, and a washer 954. The rotating pair shaft 951 is located at the lower end of the piston cylinder 94. The rolling bearing 952, the washer 954, and the round nut 953 are sequentially sleeved on the rotating pair shaft 951. The rolling bearing 952 is located on the fixed base 96.

[0084] A buffer sealing ring 2 is installed on the moving platform 1.

[0085] It should be noted that during the docking operation, the buffer sealing ring 2 serves to seal and buffer the pipeline.

[0086] Based on the parallel structure of three drive cables 31 and 3-RPS, a simplified configuration diagram of the rigid-flexible hybrid parallel docking mechanism is drawn. Variable stiffness analysis is performed on this mechanism configuration to measure its stiffness performance at a fixed position. The Euclidean norm 2 of the stiffness matrix in Cartesian space is defined to measure the overall stiffness of the mechanism. Its calculation method is achieved by the following formula:

[0087] Formula (1): The overall stiffness matrix of the rigid-flexible hybrid parallel docking mechanism is:

[0088] K = K1 + K2 + K3 + K4

[0089] in:

[0090] K1 is the structural stiffness matrix related to the driving steel cable 31;

[0091] K2 is the force stiffness matrix related to the driving steel cable 31;

[0092] K3 is the structural stiffness matrix related to the passive elastic branch 9;

[0093] K4 is the force stiffness matrix related to the passive elastic branch 9.

[0094] Formula (2):

[0095]

[0096] A larger D(K) value indicates a greater overall stiffness of the mechanism.

[0097] The second slider 63 on the fixed platform 7 can slide on the second slide rail base 61 to change the position of the pulley device 62. The guide position of the drive cable 31 as it passes over the pulley device 62 also changes accordingly, thereby adjusting the position of the cable anchor point A and thus changing the value of r. The first slider 101 on the moving platform 1 can slide on the first slide rail base 102, and the position of the drive cable 31 at the cable anchor point B on the moving platform 1 also changes accordingly, thus changing the value of r. Overall, by adjusting the positions of the cable anchor points A and B, the configuration of the rigid-flexible hybrid parallel connection mechanism is changed.

[0098] Adjust the positions of steel cable anchor points A and B to obtain the parameters of R and r for Examples 1 to 4. Then, combine formula (1) and formula (2) to draw the stiffness performance spectrum of the rigid-flexible hybrid parallel docking mechanism.

[0099] Example 1:

[0100] When R = 120mm and r = 120mm, see the simplified configuration diagram of the rigid-flexible hybrid parallel docking mechanism. Figure 9 As shown, see the stiffness performance diagram. Figure 10 As shown.

[0101] Example 2:

[0102] When R = 120 mm and r = 100 mm, see the simplified configuration diagram of the rigid-flexible hybrid parallel docking mechanism. Figure 11 As shown, see the stiffness performance diagram. Figure 12 As shown.

[0103] Example 3:

[0104] When R = 120mm and r = 80mm, see the simplified configuration diagram of the rigid-flexible hybrid parallel docking mechanism. Figure 13As shown, see the stiffness performance diagram. Figure 14 As shown.

[0105] Example 4:

[0106] When R = 120mm and r = 60mm, see the simplified configuration diagram of the rigid-flexible hybrid parallel docking mechanism. Figure 15 As shown, see the stiffness performance diagram. Figure 16 As shown.

[0107] In summary, setting the ratio of r / R to 'a', the stiffness performance of the rigid-flexible hybrid parallel docking mechanism increases with the increase of 'a'. A graph showing the change of stiffness performance indices with the r / R value within the range of 0.5 to 1 for 'a' is provided. Figure 17 As shown, the closer the value of a = r / R is to 1, the greater the overall stiffness of the mechanism.

[0108] When a = r / R = 1, adjust the positions of steel cable anchor point A and steel cable anchor point B to obtain the parameters of R and r in Examples 5 to 8, and then draw the stiffness performance spectrum of the rigid-flexible hybrid parallel docking mechanism by combining formula (1) and formula (2).

[0109] Example 5:

[0110] When R = 60mm and r = 60mm, see the simplified configuration diagram of the rigid-flexible hybrid parallel docking mechanism. Figure 18 As shown, see the stiffness performance diagram. Figure 19 As shown.

[0111] Example 6:

[0112] When R = 80mm and r = 80mm, see the simplified configuration diagram of the rigid-flexible hybrid parallel docking mechanism. Figure 20 As shown, see the stiffness performance diagram. Figure 21 As shown.

[0113] Example 7:

[0114] When R = 100mm and r = 100mm, see the simplified configuration diagram of the rigid-flexible hybrid parallel docking mechanism. Figure 22 As shown, see the stiffness performance diagram. Figure 23 As shown.

[0115] Example 8:

[0116] When R = 120mm and r = 120mm, see the simplified configuration diagram of the rigid-flexible hybrid parallel docking mechanism. Figure 24 As shown, see the stiffness performance diagram. Figure 25 As shown.

[0117] In summary, when a = r / R = 1, the stiffness of the mechanism increases with the increase of the values ​​of R and r. A graph showing the change of stiffness performance indices with the value of r = R within the range of 60mm to 120mm is provided. Figure 26 As shown, keeping a = r / R = 1, the larger the values ​​of R and r, the greater the overall stiffness of the mechanism.

[0118] Therefore, to further optimize the mechanism design and improve the overall stiffness performance, both R and r can be set to 120mm. Alternatively, by adjusting the parameters of R and r, a corresponding mechanism configuration can be obtained, achieving suitable mechanism stiffness performance to adapt to different load conditions and improve the system's flexibility and adaptability.

[0119] The specific docking principle of this invention is as follows:

[0120] The rigid-flexible hybrid parallel docking mechanism of the present invention is installed on the gantry crane equipment at the port terminal. Before docking, the positions of the first slider 101 and the pulley assembly 6 are adjusted so that the first slider 101 is locked relative to the first slide rail base 102 and the pulley assembly 6 is locked relative to the second slide rail base 61. That is, the values ​​of r and R are determined. At this time, the configuration of the rigid-flexible hybrid parallel docking mechanism is determined. Under the operation of the operator, the present invention moves closer to the docking target platform on the berthed ship. When the moving platform 1 is close to the target platform, the claw assembly 11 receives the signal from the external signal control device and controls the hydraulic cylinder 112 to start. The hydraulic cylinder 112 pushes the hydraulic rod 113 to move and then pushes the clamping gripper 111 to rotate, realizing the clamping between the moving platform 1 and the target platform. At this time, the docking operation is completed.

[0121] Due to the influence of the water surface environment at the port shore, berthed vessels experience rolling, pitching, and heaving movements. These movements are transmitted to an external microcontroller control system via sensors in the form of electrical signals. The external microcontroller control system controls the drive motor 34 to rotate, which in turn drives the winch of the reducer 33 to rotate. The rotation of the winch controls the extension and shortening of the drive cable 31, adjusting the length of the drive cable in real time. The above process constitutes the motion input. In conjunction with the rotation of the pulley device 62 relative to the second slider 63, the rotation between the ball head 92 and the ball joint base 91, the movement between the piston rod 93 and the piston cylinder 94, and the rotation between the rotating joint 95 and the fixed base 96, the spring 97 remains in a compressed state, ensuring that the drive cable 31 is always taut. This controls the moving platform 1 to generate corresponding motion outputs, thereby compensating for the rolling, pitching, and heaving movements caused by the environmental influences on berthed vessels.

[0122] Once the port's energy replenishment or liquid cargo loading and unloading operations are completed, the hydraulic rod 113 in the control claw assembly 11 is retracted first, the gripper 111 is released, and under the operation of the staff, the gantry crane will detach the moving platform 1 from the target platform, thus completing the entire docking operation.

[0123] In summary, the beneficial effects of this invention are:

[0124] (1) By adopting three passive elastic branches 9 to form a 3-RPS parallel structure, the moving platform 1 is constrained to move along the x-axis and y-axis and rotate around the z-axis. By setting three driving devices 3, under the action of three driving steel cables 31, the moving platform 1 can realize rotation around the x-axis and y-axis and movement along the z-axis, which meets the actual needs of docking operation. The rigid-flexible hybrid design has a greater advantage in ensuring the safety of attitude adjustment during docking.

[0125] (2) By setting movable first slider 101 and pulley assembly 6 on moving platform 1 and fixed platform 7 respectively, the values ​​of r and R can be adjusted, the positions of the three drive steel cables 31 can be changed, and the stiffness of the mechanism can be adjusted to adapt to different load conditions, improve the flexibility and adaptability of the system. This variable mechanism configuration has variable stiffness characteristics, which can optimize the energy absorption and dispersion of the load, reduce the damage to the docking mechanism, and extend the service life of the equipment.

[0126] All the devices selected in this application are general standard parts or components known to those skilled in the art. Their structures and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0127] In the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0128] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0129] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A rigid-flexible hybrid parallel docking mechanism, characterized in that, include: The fixed platform (7), the moving platform (1), and three passive elastic branches (9) connecting the fixed platform (7) and the moving platform (1) are provided. The moving platform is used to dock with an external target platform. Each of the passive elastic branches (9) includes a piston rod (93) and a piston cylinder (94) connected to each other. The upper end of the piston rod (93) is connected to the moving platform (1) through a ball joint, and the lower end of the piston cylinder (94) is rotatably connected to the fixed platform (7) through a rotating joint. Three driving devices (3) are arranged alternately with the passive elastic branch (9). Each driving device (3) includes a first slider (101), a first slide rail base (102), a driving cable (31), a pulley assembly (6), a second slide rail base (61), and a motor assembly (32). The first slide rail base (102) is arranged around the central spokes of the moving platform (1), and the second slide rail base (61) is arranged around the central spokes of the fixed platform (7). The first slide rail base (102) is disposed on the lower end surface of the moving platform (1). The first slider (101) is slidably connected to the first slide rail base (102). The upper end of the driving cable (31) is connected to the first slider (101). The lower end of the driving cable (31) passes through the pulley assembly (6) and is connected to the motor assembly (32). The second slide rail base (61) is disposed on the fixed platform (7). The pulley assembly (6) is slidably connected to the second slide rail base (61).

2. The rigid-flexible hybrid parallel docking mechanism as described in claim 1, characterized in that, The three first sliders (101) have the same structure and are symmetrical about the center of the moving platform (1). The first slide rail base (102) has the same structure and is symmetrical about the center of the moving platform (1). A cable anchor point B is formed at the connection between the driving cable (31) and the first slider (101). The three cable anchor points B are connected in sequence to form a second triangle. The circumcircle of the second triangle is S2, and the radius of S2 is r. The first slider (101) can move towards or away from the center of the moving platform (1) to change the parameter r. The range of r is 60mm to 120mm.

3. The rigid-flexible hybrid parallel docking mechanism as described in claim 2, characterized in that, A cable anchor point A is formed at the contact point between the drive cable (31) and the pulley assembly (6). The three cable anchor points A are connected in sequence to form a first triangle. The circumcircle of the first triangle is S1, and the radius of S1 is R. The pulley end can move towards or away from the center of the fixed platform (7) to change the parameter of R. The range of R is 60mm to 120mm. The ratio of r to R is set to a, where a = r / R. The stiffness performance of the rigid-flexible hybrid parallel docking mechanism increases with the increase of a. When a = r / R = 1, the stiffness performance of the rigid-flexible hybrid parallel docking mechanism increases with the increase of the values ​​of r and R.

4. The rigid-flexible hybrid parallel docking mechanism as described in claim 1, characterized in that, Also includes: Three gripper assemblies (11) are provided on the moving platform (1). One end of each gripper assembly (11) is rotatably connected to the moving platform (1), and the other end of each gripper assembly (11) extends toward the center of the moving platform (1) to clamp the external target platform.

5. A rigid-flexible hybrid parallel docking mechanism as described in claim 4, characterized in that, The three jaw assemblies (11) have the same structure and are symmetrical about the center of the fixed platform (7). Each jaw assembly (11) includes: a clamping gripper (111), a hydraulic rod (113), and a hydraulic cylinder (112). The upper end of the clamping gripper (111) extends toward the center of the moving platform (1) to clamp the external target platform. The middle part of the clamping gripper is rotatably connected to the moving platform (1). One end of the hydraulic rod (113) is connected to the lower end of the clamping gripper (111) through a cylindrical joint. The hydraulic cylinder (112) is mounted on the lower end face of the moving platform (1) through a third mounting bolt (8). The other end of the hydraulic rod (113) is connected to the hydraulic cylinder (112).

6. The rigid-flexible hybrid parallel docking mechanism as described in claim 1, characterized in that, The three pulley assemblies (6) have the same structure and are symmetrical about the center of the fixed platform (7). Each pulley assembly (6) includes a pulley device (62) and a second slider (63). The pulley device (62) is rotatably mounted on the second slider (63). The second slider (63) is slidably connected to the second slide rail base (61). The drive cable (31) passes through the pulley device (62) and is connected to the motor assembly (32).

7. The rigid-flexible hybrid parallel docking mechanism as described in claim 1, characterized in that, The three motor assemblies (32) have the same structure and are symmetrical about the center of the fixed platform (7). Each motor assembly (32) includes a drive motor (34) and a reducer (33) connected to each other. The drive motor (34) and the reducer (33) are both mounted on the fixed platform (7). The lower end of the drive cable (31) passes through the pulley assembly (6) and is connected to the rotating winch of the reducer (33).

8. The rigid-flexible hybrid parallel docking mechanism as described in claim 1, characterized in that, The three ball joints are identical in structure and symmetrical about the center of the fixed platform (7). Each ball joint includes a ball joint base (91) and a ball head (92). The ball joint base (91) is disposed on the lower end surface of the moving platform (1). The ball head (92) is rotatably connected to the ball joint base (91). One end of the piston rod (93) is connected to the ball head (92).

9. A rigid-flexible hybrid parallel docking mechanism as described in claim 8, characterized in that, The passive elastic branch (9) also includes a fixed base (96) and a spring (97). The fixed base (96) is disposed on the fixed platform (7). The spring (97) is fitted on the outside of the piston rod (93). The lower end of the spring (97) abuts against the piston cylinder (94). The rotating pair (95) includes a rotating pair shaft (951), a rolling bearing (952), a round nut (953), and a washer (954). The rotating pair shaft (951) is disposed at the lower end of the piston cylinder (94). The rolling bearing (952), the washer (954), and the round nut (953) are sequentially fitted on the rotating pair shaft (951). The rolling bearing (952) is disposed on the fixed base (96).

10. A rigid-flexible hybrid parallel docking mechanism as described in claim 8, characterized in that, The moving platform (1) is provided with a buffer sealing ring (2).

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