Serial-parallel six-degree-of-freedom pose adjustment mechanism and target pose adjustment method thereof

Abstract

The present application relates to a kind of mixed six degrees of freedom pose adjustment mechanism, including base, horizontal shift drive mechanism, horizontal shift platform, longitudinal shift drive mechanism, rotary support platform, rotating mechanism, rotating platform, three groups of kinematic branch and end load platform;Horizontal shift platform is installed on base by horizontal shift drive mechanism, to move laterally under its drive, rotary support platform is installed on horizontal shift platform by longitudinal shift drive mechanism, to move longitudinally under its drive, rotating platform is installed on rotary support platform by rotating mechanism, to rotate around vertical direction under its drive, three groups of symmetrical arrangement kinematic branch one end is rotatably connected with rotating platform, the other end is connected with end load platform by spherical hinge;Through the coordinated movement of horizontal shift platform, rotary support platform, rotating platform and three groups of kinematic branch, six degrees of freedom pose adjustment to end load is realized in certain workspace.The mechanism can be full degree of freedom pose adjustment to end load.

Description

Technical Field

[0001] This invention relates to the field of mechanical manufacturing technology, specifically to a hybrid six-degree-of-freedom pose adjustment mechanism and its target pose adjustment method. Background Technology

[0002] In military and chemical industries, it is often necessary to load and unload heavy hazardous materials. After moving the hazardous materials to the target location, their attitude needs to be adjusted, including lifting, lowering, longitudinal movement, lateral movement, rotation, pitching, and rolling, so that the lifting lugs can accurately dock with the target attachment point. Manual operation is inefficient, requires high levels of professional skills and physical fitness from operators, and often requires multiple people to work together. Furthermore, manual operation is time-consuming and labor-intensive when working in low-ceilinged attachment points. Another method, hydraulic drive, can meet the requirements of heavy load operations, but the platform is heavy and usually requires manual remote control in an open-loop control manner for loading and unloading hazardous materials. Automation control accuracy is low, and operator cooperation is required during loading operations, demanding high operator skills. Moreover, the complexity of this drive system makes troubleshooting difficult. How to quickly adjust the projectile's attitude based on the attachment point's position information to complete the loading and docking is a pressing problem that needs to be solved. Summary of the Invention

[0003] The purpose of this invention is to provide a hybrid six-degree-of-freedom pose adjustment mechanism and its target pose adjustment method, which can perform full-degree-of-freedom pose adjustment on the end-effector load.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is: a hybrid six-degree-of-freedom pose adjustment mechanism, comprising a base, a lateral movement drive mechanism, a lateral movement platform, a longitudinal movement drive mechanism, a rotation support platform, a rotation mechanism, a rotation platform, three sets of motion chains, and an end-load platform; the lateral movement platform is mounted on the base via the lateral movement drive mechanism to move laterally under its drive; the rotation support platform is mounted on the lateral movement platform via the longitudinal movement drive mechanism to move longitudinally under its drive; the rotation platform is mounted on the rotation support platform via the rotation mechanism to rotate around the vertical direction under its drive; one end of the three symmetrically arranged motion chains is rotatably connected to the rotation platform, and the other end is connected to the end-load platform via a ball joint; through the coordinated movement of the lateral movement platform, the rotation support platform, the rotation platform, and the three sets of motion chains, six-degree-of-freedom pose adjustment of the end-load is achieved within a certain workspace.

[0005] Furthermore, the posture adjustment mechanism has six drive joints, of which the lateral, longitudinal, and vertical rotation joints are connected in series and connected in series with the other three joints that are connected in parallel. Each joint has a certain range of motion. When the joints move in coordination, the end load moves to the predetermined position and locks.

[0006] Furthermore, both the transverse drive mechanism and the longitudinal drive mechanism are screw and nut mechanisms driven by motors.

[0007] Furthermore, the rotating mechanism includes a slewing support bearing, a pair of spur gears, a slewing drive motor, a pair of bevel gears, and a transmission rod. The first spur gear and the outer ring of the slewing support bearing are concentrically and fixedly connected to the rotating support platform. The inner ring of the slewing support bearing is concentrically and fixedly connected to the rotating platform. The slewing drive motor is mounted on the rotating platform, and its output end is fixedly connected to the first bevel gear. The second bevel gear, which cooperates with the first bevel gear, and the second spur gear, which cooperates with the first spur gear, are respectively located at both ends of the transmission rod, thereby driving the rotating platform to rotate relative to the rotating support platform through the slewing drive motor.

[0008] Furthermore, the motion chain mainly consists of a chain drive motor, a drive base, a worm gear, a moving rod, a connecting sleeve, a revolute joint, and an encoder. The connecting sleeve is connected to the rotating platform via a revolute joint. The chain drive motor is fixed to the connecting sleeve via the drive base. The moving rod and the worm gear are coaxial and connected to the worm gear via a threaded joint. The bottom of the moving rod has a keyway, and the circumferential rotation of the moving rod is restricted by a flat key. The power output by the chain drive motor drives the worm gear to rotate through the worm, and the worm gear drives the moving rod to move axially through the threaded joint.

[0009] This invention also provides a target pose adjustment method for the above-mentioned hybrid six-DOF pose adjustment mechanism, firstly by constructing a mathematical motion model of the pose adjustment mechanism:

[0010] The posture adjustment mechanism is divided into a series part and a parallel part according to the connection method of each joint;

[0011] Take the driving quantity q of each joint in the series connection. i Let i = 1, 2, 3 be the input variables, and the output be the pose T1 of the end effector. The mapping relationship is expressed as follows:

[0012] T1=f(q i )

[0013] Where T1 represents the output pose of the serial part;

[0014] The output pose of the parallel end platform is represented by a certain sequence of rotations and movements of the coordinate system fixed to the end platform around the coordinate system fixed to the stationary platform, specifically:

[0015] R=Rot(x,α)Rot(y,β)Rot(z,γ)

[0016] P = Trans(x)Trans(y)Trans(z)

[0017] Where R represents the pose of the parallel end platform relative to the static platform, Rot(x, α) represents the rotation of the static platform coordinate system around the x-axis by α degrees, and Rot(y, β) and Rot(z, γ) are similar, P represents the position coordinates of the origin of the end platform coordinate system in the static platform coordinate system, Trans(x) represents the movement of the static platform coordinate system along the x-axis, and Trans(y) and Trans(z) are similar;

[0018] The output of the series section of the pose adjustment mechanism is the input of the parallel section. Therefore, the mathematical motion model of the pose adjustment mechanism can be further expressed as:

[0019]

[0020] Where T represents the output pose of the entire pose adjustment mechanism;

[0021] Then, based on the constructed mathematical motion model, the load target pose adjustment mechanism is implemented:

[0022] Based on the constructed mathematical motion model, the motion parameters of each driving joint can be decoupled, and the target pose T with known end-effector load can be achieved. E At that time, combining the mathematical motion model of the pose adjustment mechanism and the values ​​of each element of the target pose matrix, the driving amount of each drive joint is calculated, specifically expressed as follows:

[0023]

[0024] Where F() represents the mapping relationship between the mechanism's pose and the motion of each joint. T represents the target pose matrix. E The elements in;

[0025] The obtained drive joint drive amount is used as the input to the drive system of the posture adjustment mechanism, which can drive the end load to the set posture.

[0026] Compared with the prior art, the present invention has the following beneficial effects: The present invention constructs a hybrid six-degree-of-freedom pose adjustment mechanism composed of three serial joints and three parallel joints. By controlling the transverse drive mechanism, the longitudinal drive mechanism, the rotation mechanism, and the three sets of motion chains, the coordinated movement of the transverse platform, the rotation support platform, the rotation platform, and the three sets of motion chains can be realized. Thus, the six-degree-of-freedom pose adjustment of the end load can be realized within a certain workspace. The mechanism has a wide range of motion, high stiffness and driving force, flexible pose control, and high precision. It can adapt to a variety of complex working conditions and has strong practicality and broad application prospects. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the hybrid six-degree-of-freedom pose adjustment mechanism according to an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the kinematic branch structure in an embodiment of the present invention;

[0029] Figure 3 yes Figure 2 AA section view;

[0030] Figure 4 yes Figure 2 BB cross-sectional view;

[0031] Figure 5 This is a flowchart illustrating the target pose implementation in an embodiment of the present invention. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0033] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0034] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0035] like Figure 1As shown, this embodiment provides a hybrid six-DOF pose adjustment mechanism, including a base 1, a transverse drive mechanism 2, a transverse platform 3, a longitudinal drive mechanism 4, a rotational support platform 5, a rotational mechanism 6, a rotational platform 7, three sets of motion chains 8, and an end-load platform 9. The transverse platform 3 is mounted on the base 1 via the transverse drive mechanism 2 for transverse movement under its drive. The rotational support platform 5 is mounted on the transverse platform 3 via the longitudinal drive mechanism 4 for longitudinal movement under its drive. The rotational platform 7 is mounted on the rotational support platform 5 via the rotational mechanism 6 for rotation around the vertical direction under its drive. One end of the three symmetrically arranged motion chains 8 is rotatably connected to the rotational platform 7, and the other end is connected to the end-load platform 9 via a ball joint. Through the coordinated movement of the transverse platform 3, the rotational support platform 5, the rotational platform 7, and the three sets of motion chains 8, six-DOF pose adjustment of the end-load is achieved within a certain workspace.

[0036] The posture adjustment mechanism has six drive joints, of which the lateral, longitudinal, and vertical rotation joints are connected in series and connected in series with the other three joints that are connected in parallel. Each joint has a certain range of motion. When the joints move in coordination, the end load moves to the predetermined position and locks.

[0037] In this embodiment, both the transverse drive mechanism and the longitudinal drive mechanism are screw and nut mechanisms driven by a motor.

[0038] In this embodiment, the rotating mechanism 6 includes a slewing support bearing, a pair of spur gears 61, a slewing drive motor 62, a pair of bevel gears 63, and a transmission rod 64. The first spur gear and the outer ring of the slewing support bearing are concentrically and fixedly connected to the rotating support platform. The inner ring of the slewing support bearing is concentrically and fixedly connected to the rotating platform. The slewing drive motor is mounted on the rotating platform, and its output end is fixedly connected to the first bevel gear. The second bevel gear that cooperates with the first bevel gear and the second spur gear that cooperates with the first spur gear are respectively disposed at both ends of the transmission rod, thereby driving the rotating platform to rotate relative to the rotating support platform through the slewing drive motor.

[0039] like Figure 2-4 As shown, in this embodiment, the motion chain 8 mainly consists of a chain drive motor 81, a drive base 82, a worm gear 83, a worm 84, a moving rod 85, a connecting sleeve 86, a rotary joint 87, and an encoder 88. The connecting sleeve is connected to the rotating platform via a rotary joint. The chain drive motor is fixed to the connecting sleeve via the drive base. The moving rod and the worm gear are coaxial and connected to the worm gear via a threaded joint. The bottom of the moving rod has a keyway, and the circumferential rotation of the moving rod is restricted by a flat key. The power output by the chain drive motor drives the worm gear to rotate via the worm. The worm gear drives the moving rod to move axially via the threaded joint.

[0040] This embodiment also provides a target pose adjustment method for the above-mentioned hybrid six-DOF pose adjustment mechanism, specifically including:

[0041] 1. Construct a mathematical motion model for the posture adjustment mechanism.

[0042] The posture adjustment mechanism is divided into series and parallel parts according to the connection method of each joint.

[0043] Take the driving quantity q of each joint in the series connection. i Let i = 1, 2, 3 be the input variables, and the output be the pose T1 of the end effector. The mapping relationship is expressed as follows:

[0044] T1=f(q i )

[0045] Where T1 represents the output pose of the serial part.

[0046] The output pose of the parallel end-effector platform is represented by a certain sequence of rotations and movements of the end-effector platform around the stationary platform, specifically:

[0047] R = Rot(x)Rot(y)Rot(z)

[0048] P = Trans(x, y, z)

[0049] Where R represents the pose of the parallel end platform relative to the stationary platform, Rot(x, α) represents the rotation of the stationary platform coordinate system around the x-axis by α degrees, and Rot(y, β) and Rot(z, γ) are similar. P represents the position coordinates of the origin of the end platform coordinate system in the stationary platform coordinate system, Trans(x) represents the movement of the stationary platform coordinate system along the x-axis, and Trans(y) and Trans(z) are similar.

[0050] The output of the series section of the pose adjustment mechanism is the input of the parallel section. Therefore, the mathematical motion model of the pose adjustment mechanism can be further expressed as:

[0051]

[0052] Where T represents the output pose of the pose adjustment mechanism.

[0053] 2. The load target pose adjustment of the pose adjustment mechanism is realized based on the constructed mathematical motion model.

[0054] Based on the constructed mathematical motion model, the motion parameters of each driving joint can be decoupled, and the target pose T with known end-effector load can be achieved. EAt that time, combining the mathematical motion model of the pose adjustment mechanism and the values ​​of each element of the target pose matrix, the driving amount of each drive joint is calculated, specifically expressed as follows:

[0055]

[0056] Where F() represents the mapping relationship between the mechanism's pose and the motion of each joint. T represents the target pose matrix. E The various elements in it.

[0057] The obtained drive joint drive amount is used as the input to the drive system of the posture adjustment mechanism, which can drive the end load to the set posture.

[0058] The target pose realization process in this embodiment is as follows: Figure 5 As shown. First, based on the established mathematical motion model, i.e., the mechanism kinematic model, and utilizing the equivalence principle between the mechanism kinematic model and the target pose, according to the analytical relationship between each element of the pose matrix in the mechanism kinematic model and each joint of the mechanism, the corresponding target pose matrix elements are substituted to obtain the driving amount of each joint. The boundary conditions of each joint driving amount are used to determine whether the target pose is achievable. If so, the obtained driving amount is used as the input command for the mechanism drive system. After the command is executed, the end effector load reaches the predetermined target pose. Otherwise, the motion platform where the pose adjustment mechanism is located is output as an adjustment command. After the adjustment is completed, the boundary condition judgment continues until it is satisfied.

[0059] The hybrid six-DOF pose adjustment mechanism provided by this invention can achieve full-DOF pose adjustment of a load placed on its end-effector within a certain workspace. Simultaneously, it can be fixed as an independent module to any mobile platform to achieve load pose adjustment over a larger workspace and application area, exhibiting a certain degree of scalability. This invention breaks down the hybrid six-DOF pose adjustment mechanism into series and parallel parts according to the joint connection method, establishing kinematic models for each. Then, based on the relationship between the output of the series system and the input of the parallel system, an overall mathematical kinematic model of the pose adjustment mechanism is established. Furthermore, the kinematic parameters of each driving joint can be decoupled, laying the foundation for the subsequent realization of the target pose. Using the mathematical kinematic model of the pose adjustment mechanism, after knowing the target pose of the end-effector load, the target pose parameters are used as input. Based on the parameter-decoupled kinematic model, the driving quantities of each driving joint can be solved. If the driving quantity of any joint satisfies the boundary conditions of the joint driving quantity, the pose is achievable; otherwise, the mobile platform connected to the pose adjustment mechanism is adjusted. This invention fully utilizes the advantages of serial and parallel mechanisms, offering a wide range of motion, high stiffness, and high precision. When this mechanism is connected as a module to other motion platforms, it reduces the difficulty of kinematic control and planning for the entire system, thereby improving planning efficiency.

[0060] The design process of the hybrid six-DOF pose adjustment mechanism proposed in this invention is as follows:

[0061] 1. Using 3D software, establish 3D models of each component of the hybrid six-DOF pose adjustment mechanism, rationally set the constraints and coordination relationships between the components, and complete the establishment of the overall 3D model. Then, perform motion simulation on the designed hybrid six-DOF pose adjustment mechanism to obtain the motion simulation results, thus completing the model design of the hybrid six-DOF pose adjustment mechanism.

[0062] 2. Establish the kinematic model of the pose adjustment mechanism, including the kinematic model of the serial mechanism after splitting, the kinematic model of the parallel mechanism, the mathematical relationship between the input of the serial mechanism and the input of the parallel mechanism, and the overall mathematical kinematic model of the hybrid six-degree-of-freedom pose adjustment mechanism.

[0063] 3. Based on the constructed mathematical motion model, the target pose is used as the input for pose realization. According to the equivalence principle between the target pose and the mathematical motion model, each input condition is substituted into the mathematical motion model to calculate the driving quantity of each joint of the mechanism. Then, the boundary conditions of each joint driving quantity are used to determine whether the target pose is achievable. If the boundary conditions are met, each driving quantity is used as the input command of the mechanism's drive system. After the command is executed, the end load reaches the target pose. Otherwise, the adjustment command of the motion platform where the pose adjustment mechanism is located is output. After the adjustment is completed, the boundary condition judgment is continued until the boundary conditions are met.

[0064] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0065] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0066] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0067] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0068] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A hybrid six-degree-of-freedom pose adjustment mechanism, characterized in that, The system includes a base, a lateral drive mechanism, a lateral platform, a longitudinal drive mechanism, a rotating support platform, a rotating mechanism, a rotating platform, three sets of motion chains, and an end-load platform. The lateral platform is mounted on the base via the lateral drive mechanism for lateral movement. The rotating support platform is mounted on the lateral platform via the longitudinal drive mechanism for longitudinal movement. The rotating platform is mounted on the rotating support platform via the rotating mechanism for rotation about the vertical direction. One end of each of the three symmetrically arranged motion chains is rotatably connected to the rotating platform, and the other end is connected to the end-load platform via a ball joint. Through the coordinated movement of the lateral platform, rotating support platform, rotating platform, and the three sets of motion chains, six-degree-of-freedom pose adjustment of the end-load is achieved within a certain workspace.

2. The hybrid six-degree-of-freedom pose adjustment mechanism according to claim 1, characterized in that, The posture adjustment mechanism has six drive joints, of which the lateral, longitudinal, and vertical rotation joints are connected in series and connected in series with the other three joints that are connected in parallel. Each joint has a certain range of motion. When the joints move in coordination, the end load moves to the predetermined position and locks.

3. The hybrid six-degree-of-freedom pose adjustment mechanism according to claim 1, characterized in that, Both the transverse and longitudinal drive mechanisms are screw and nut mechanisms driven by motors.

4. The hybrid six-degree-of-freedom pose adjustment mechanism according to claim 1, characterized in that, The rotating mechanism includes a slewing support bearing, a pair of spur gears, a slewing drive motor, a pair of bevel gears, and a transmission rod. The first spur gear and the outer ring of the slewing support bearing are concentric and fixedly connected to the rotating support platform. The inner ring of the slewing support bearing is concentric and fixedly connected to the rotating platform. The slewing drive motor is mounted on the rotating platform, and its output end is fixedly connected to the first bevel gear. The second bevel gear, which cooperates with the first bevel gear, and the second spur gear, which cooperates with the first spur gear, are respectively located at both ends of the transmission rod, thereby driving the rotating platform to rotate relative to the rotating support platform through the slewing drive motor.

5. The hybrid six-degree-of-freedom pose adjustment mechanism according to claim 1, characterized in that, The motion chain mainly consists of a chain drive motor, a drive base, a worm gear, a moving rod, a connecting sleeve, a revolute joint, and an encoder. The connecting sleeve is connected to the rotating platform via a revolute joint. The chain drive motor is fixed to the connecting sleeve via the drive base. The moving rod and the worm gear are coaxial and connected to the worm gear via a threaded joint. The bottom of the moving rod has a keyway, and the circumferential rotation of the moving rod is restricted by a flat key. The power output by the chain drive motor drives the worm gear to rotate through the worm, and the worm gear drives the moving rod to move axially through the threaded joint.

6. A target pose adjustment method for a hybrid six-DOF pose adjustment mechanism according to any one of claims 1-5, characterized in that, First, construct the mathematical motion model of the pose adjustment mechanism: The posture adjustment mechanism is divided into a series part and a parallel part according to the connection method of each joint; Take the driving quantity q of each joint in the series connection. i Let i = 1, 2, 3 be the input variables, and the output be the pose T1 of the end effector. The mapping relationship is expressed as follows: T1=f(q i ) Where T1 represents the output pose of the serial part; The output pose of the parallel end platform is represented by a certain sequence of rotations and movements of the coordinate system fixed to the end platform around the coordinate system fixed to the stationary platform, specifically: R=Rot(x,α)Rot(y,β)Rot(z,γ) P = Trans(x)Trans(y)Trans(z) Where R represents the pose of the parallel end platform relative to the stationary platform, Rot(x, α) represents the rotation of the stationary platform coordinate system around the x-axis by α degrees, and Rot(y, β) and Rot(z, γ) are similar, P represents the position coordinates of the origin of the end platform coordinate system in the stationary platform coordinate system, Trans(x) represents the movement of the stationary platform coordinate system along the x-axis, and Trans(y) and Trans(z) are similar; The output of the series section of the pose adjustment mechanism is the input of the parallel section. Therefore, the mathematical motion model of the pose adjustment mechanism can be further expressed as: Where T represents the output pose of the entire pose adjustment mechanism; Then, based on the constructed mathematical motion model, the load target pose adjustment mechanism is implemented: Based on the constructed mathematical motion model, the motion parameters of each driving joint can be decoupled, and the target pose T with known end-effector load can be achieved. E At that time, combining the mathematical motion model of the pose adjustment mechanism and the values ​​of each element of the target pose matrix, the driving amount of each drive joint is calculated, specifically expressed as follows: Where F() represents the mapping relationship between the mechanism's pose and the motion of each joint. Represents the target pose matrix T E The elements in; The obtained drive joint drive amount is used as the input to the drive system of the posture adjustment mechanism, which can drive the end load to the set posture.

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