Reconfigurable two-translation and two-rotation series-parallel mechanism

Abstract

The invention discloses a reconfigurable two-translation and two-rotation series-parallel hybrid mechanism which comprises a hollow rotating platform, a fixed base, a rack, a branch mechanism and a movable platform. The fixed base is installed on the hollow rotating platform and fixedly connected with the rack; three parallel rack guide rails with unequal axis distances are vertically arranged on the front face and the two side faces of the rack, a branch mechanism is correspondingly arranged at each rack guide rail, and a rigid rod in each branch mechanism is connected with a sliding block and a movable platform through a hinge. The rotating pair of the hollow rotating platform of the series-parallel mechanism and the moving pairs in the three branch mechanisms are all actively driven, and the freedom degree of two-translation and two-rotation of the mechanism is achieved. Within the circumferential range, the mechanism drives the series-parallel hybrid mechanism to rotate to the designated direction through the hollow rotating platform, and under the condition that the working range in the vertical direction is large, the mechanism can splice the rack, the branch mechanism and the movable platform which are of the same structure in the direction of the guide rail, so that the working space extends in the vertical direction or multiple sets of series-parallel hybrid mechanisms work at the same time. On the premise of gathering the advantages of narrow transverse width, small dead weight, good stability and the like, the mechanism is ensured to rotate in the circumferential range of a working space and work in a large range in the height direction, so that the mechanism has a good working effect.

Description

Technical Field

[0001] The present invention relates to the technical field of facility agriculture, and in particular to a reconfigurable two-translation and two-rotation serial-parallel hybrid mechanism. The present invention relates to a facility agriculture operation device, and in particular to an R-3PRR serial-parallel hybrid mechanism facility agriculture operation device with an adjustable motion range. Background Art

[0002] In the current field of facility agriculture, robotic arm technology has been widely used, especially in the pruning of fruit trees and seedlings, pesticide spraying, grafting and picking. However, in the actual agricultural production process, the facility agriculture environment has higher requirements for the positioning accuracy and rigidity of the robotic arm. Most of the commonly used serial robotic arms in China are composed of multiple revolute pairs in series, and each joint is equipped with an independent motor, so that the robotic arm can achieve flexible movement in a fixed workspace. However, this design also has obvious limitations. If it is necessary to increase the horizontal and vertical range of motion in the existing workspace, it is necessary to add additional actuators and power devices, which will not only increase the weight and inertia of the entire device, but also may affect its dynamic stability. At the same time, the newly added power device requires reconfiguration of torque and power, which undoubtedly increases the complexity of use. In contrast, the parallel mechanism has an independent control system for each branch, which shows superior performance in dynamic stability. However, the particularity of the facility agriculture environment makes the vine postures and the heights of mature fruits different at different growth stages, which makes it difficult for a single serial or parallel mechanism to adapt to such changes and to efficiently complete operations such as grafting, pruning, spraying pesticides and picking. Therefore, the traditional fixed structure robotic arm has certain limitations in practical applications and needs further innovation and improvement. Summary of the invention

[0003] The purpose of the present invention is to provide a reconfigurable two-translational and two-rotational series-parallel hybrid mechanism to solve the problems existing in the above-mentioned prior art. It is an R-3PRR series-parallel hybrid mechanism based on a parallel mechanism, and its three rack guide rails are distributed on the front and two sides of the frame, so that the overall volume and moment of inertia of the mechanism are small, and the working stroke in the height direction can be adjusted with environmental changes, so that the working range can be extended along the guide rail direction or multiple groups of parallel mechanisms can work simultaneously, which has important practical significance for the automation operation of facility agriculture.

[0004] To achieve the above object, the present invention provides the following solution: The present invention provides a reconfigurable two-translation two-rotation series-parallel hybrid mechanism, comprising

[0005] A hollow rotating platform, on which a fixed base is installed; and

[0006] A fixed base, the fixed base is fixedly connected to the frame;

[0007] A frame, wherein three parallel rack guide rails with unequal axis spacings are vertically provided on the front and two side surfaces of the frame, and the lateral spacing between the right rack guide rail of the frame and the front rack guide rail is twice the lateral spacing between the left rack guide rail and the front rack guide rail; and

[0008] A branch mechanism, each of the rack guide rails is provided with a branch mechanism, the branch mechanism comprising a gear, a motor, a slider, a hinge 1, a rigid rod and a hinge 2; and

[0009] A moving platform, wherein three hinge points are arranged on the moving platform, and the three hinges are respectively connected to the three hinge points on the bottom surface of the moving platform, and the bottom surface of the moving platform is used to install the end working tool; and

[0010] The frame, the branch mechanism and the moving platform form a spatial parallel closed-loop structure, the fixed base and the parallel mechanism form a series-parallel hybrid mechanism, the rotating pair of the hollow rotating platform of the series-parallel hybrid mechanism and the moving pairs in the three branch mechanisms are all actively driven, realizing two translational and two rotational degrees of freedom of the series-parallel hybrid mechanism.

[0011] For working environments at different heights, two or more racks can be spliced ​​along the guide rail direction, or racks, branches and moving platforms with the same structure can be spliced ​​along the guide rail direction to extend the working range along the height direction or allow multiple sets of parallel mechanisms to work simultaneously.

[0012] Preferably, the device can not only realize the independent operation of a serial-parallel hybrid mechanism, but also can be modularly spliced ​​according to the working environment at different heights. When two or more serial-parallel hybrid mechanisms are spliced ​​along the guide rail direction, the T-slots of the rack guide rails are sequentially butted, and the racks are connected by screws, thereby realizing the extension of the working range of the moving platform in the vertical direction.

[0013] Preferably, the rigid rods in the three branch mechanisms from left to right are rigid rod one, rigid rod two and rigid rod three, and rigid rod one and rigid rod two are short connecting rods of the same length, the length of rigid rod three is 1.5 times that of rigid rod one, and the axes of hinge one and hinge three of the three rigid rods are parallel.

[0014] Preferably, the connecting lines of the three hinge points on the moving platform are arranged in a triangle, and hinge point one and hinge point three axes are coaxial, hinge point one is located on the lower left side of the moving platform, hinge point two is located on the upper middle side of the moving platform, and hinge point three is located on the lower right side of the moving platform, thereby increasing the stability of the moving platform during movement.

[0015] Preferably, hinge 2 of the rigid rod 1 is connected to hinge point 1 on the bottom surface of the moving platform, hinge 2 of the rigid rod 2 is connected to hinge point 2 on the bottom surface of the moving platform, and hinge 2 of the rigid rod 3 is connected to hinge point 3 of the moving platform.

[0016] Compared with the prior art, the present invention has achieved the following beneficial technical effects:

[0017] A reconfigurable two-translational and two-rotational series-parallel hybrid mechanism of the present invention comprises a fixed base, a hollow rotating platform, a frame, a branch mechanism and a moving platform, wherein a fixed base is installed on the hollow rotating platform, the fixed base is fixedly connected to the frame, three rack guides are respectively arranged on the front and two side surfaces of the frame, each rack guide is respectively provided with a branch mechanism, a rigid rod in the branch mechanism connects a slider and a moving platform through a hinge, an end working tool is installed on the bottom surface of the moving platform, the rotating pair of the hollow rotating platform of the series-parallel hybrid mechanism and the moving pairs in the three branch mechanisms are all actively driven, so as to realize the two translational and two rotational degrees of freedom of the mechanism. The present invention is based on the characteristics of high rigidity and multi-degree-of-freedom coupled motion of the parallel mechanism, and uses the R-3PRR series-parallel hybrid mechanism to realize facility agriculture environment operations. The three rack guides are distributed on the front and two sides of the frame, which reduces the volume and moment of inertia of the robot arm. By splicing frames with the same structure along the guide rail direction, the height direction of the mechanism can be extended. Or, by splicing frames, branch mechanisms and moving platforms with the same structure along the guide rail direction, multiple groups of parallel mechanisms can be realized to work simultaneously. In addition, the three hinge points on the moving platform are arranged in a triangle, which can improve the dynamic stability of the moving platform during movement. At the same time, it also increases the mechanical coordination of the device, avoids motion interference, and drives the end operation tool to complete precise operations on the target object. The present invention adopts the R-3PRR series-parallel hybrid mechanism to design an operating device for a facility agriculture environment, and adopts an arrangement mode in which three rack guide rails which are parallel to each other and have unequal axis spacings are distributed on different planes of a frame; the mechanism is driven to rotate to a specified position by a rotating pair of a hollow rotating platform; for an operating environment with a large vertical height, frames, branch mechanisms and moving platforms with the same structure are spliced ​​along the guide rail direction to realize simultaneous operation of multiple groups of parallel mechanisms, which not only realizes the rotation of the robotic arm in the circumferential direction and the extension of the working space range in the height direction, but also enhances the rigidity and dynamic stability of the device, thereby obtaining efficient operation in a facility agriculture environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is the three-dimensional structure diagram of the series-parallel hybrid mechanism;

[0020] Figure 2 It is a side view of the series-parallel hybrid mechanism;

[0021] Figure 3 It is a three-dimensional structural diagram of two spliced ​​series-parallel hybrid mechanisms;

[0022] Figure 4 A partial enlarged view of two spliced ​​rack guides

[0023] In the figure: 1, frame, 2, rack guide, 3, gear, 4, motor, 5, fixed base, 6, threaded hole, 7, slider, 8, hinge one, 9, moving platform, 10, hinge point two, 11, hinge point three, 12, hinge point one, 13, hollow rotating platform, 14, rigid rod one, 15, rigid rod two, 16, rigid rod three, 17, hinge two. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] The purpose of the present invention is to provide a reconfigurable two-translational and two-rotational series-parallel hybrid mechanism to solve the problems existing in the above-mentioned prior art. It is an R-3PRR series-parallel hybrid mechanism based on a parallel mechanism, which can rotate in the circumferential direction according to the position of the target object, and the working stroke in the height direction can be adjusted with environmental changes. It can also realize the simultaneous operation of multiple groups of parallel mechanisms, and the control accuracy and rigidity are significantly improved, which has important practical significance for the automated operation of facility agriculture.

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] like Figure 1-Figure 4As shown, the present invention provides a reconfigurable two-translational and two-rotating series-parallel hybrid mechanism, including a hollow rotating platform 13, a fixed base 5, a frame 1, a branch mechanism and a moving platform 9, wherein the fixed base 5 is installed on the hollow rotating platform 13, the fixed base 5 is fixedly connected to the frame 1, and three rack guides 2 are respectively arranged on the front and two side surfaces of the frame 1, each branch mechanism comprises a gear 3, a motor 4, a slider 7 and three rigid rods, the motor 4 is fixed on one side of the slider 7, the gear 3 is installed at the lower end of the motor 4, the gear 3 is meshed with the rack guide 2, the slider 7 is connected to the rigid rod through a hinge 1 8, and the rigid rod in the branch mechanism is respectively connected to the slider 7 and the moving platform 9 through a hinge 1 8 and a hinge 2 17. When the working range in the height direction is large, a frame 1 and rack guide 2 with the same structure can be used to be spliced ​​with the initial frame along the guide direction. The three rack guides 2 are spliced ​​through T-slots so that the working stroke of the mechanism in the height direction can be adjusted as the environment changes. Alternatively, a frame 1, branch mechanism and moving platform 9 with the same structure can be spliced ​​along the guide direction, and multiple sets of parallel mechanisms can work simultaneously.

[0028] From left to right, the rigid rods in the three branch mechanisms are respectively rigid rod 14, rigid rod 2 15 and rigid rod 3 16, and rigid rod 14 and rigid rod 2 15 are short connecting rods of the same length, and rigid rod 3 16 is 1.5 times longer than rigid rod 14, and the axes of hinge 1 8 and hinge 2 17 of the three rigid rods are parallel. The three hinge points on the moving platform are arranged in a triangle, and the axes of hinge point 12 and hinge point 3 11 are coaxial, hinge point 12 is located at the lower left side of the moving platform, hinge point 2 10 is located at the upper middle side of the moving platform, and hinge point 3 11 is located at the lower right side of the moving platform, which increases the stability of the moving platform during movement. The hinge 2 17 of the rigid rod 14 is connected to the hinge point 12 on the bottom surface of the moving platform 9, the hinge 2 17 of the rigid rod 15 is connected to the hinge point 2 10 on the bottom surface of the moving platform 9, and the hinge 2 17 of the rigid rod 3 16 is connected to the hinge point 3 11 on the bottom surface of the moving platform 9.

[0029] During use, the transport and mobile device loads the serial-parallel hybrid mechanism and moves it to the target operating position. The rotating pair of the hollow rotating platform 13 of the serial-parallel hybrid mechanism and the moving pairs of the three branch mechanisms are all actively driven. Combined with the height and posture of the target object, the direction of the serial-parallel hybrid mechanism is rotated by the hollow rotating platform 5. According to the specific posture of the target object, the moving pair in the branch mechanism adjusts the horizontal and height displacement of the moving platform 9 and the rotation along the axis direction of the hinge 2 17. The end operation tool is installed under the moving platform 9 to achieve the end operation tool to achieve the operation of the target object at a precise position. At the same time, the three rack guides 2 are located on the front and two sides of the frame 1, parallel to each other and with unequal axis spacing. The lateral spacing between the right rack guide and the front rack guide is twice the lateral spacing between the left rack guide and the front rack guide. This mechanism configuration reduces the volume and moment of inertia of the robot arm, and can better achieve the precise operation of the end execution tool on the target object. The three hinge points on the moving platform are arranged in a triangle, and the axes of the hinge point 12 and the hinge point 3 11 are coaxial. When the working range in the height direction is large, a frame 1 and rack guide 2 with the same structure are used to be spliced ​​with the initial frame along the guide direction, and three rack guides 2 are spliced ​​through T-slots so that the working stroke of the mechanism in the height direction can be adjusted as the environment changes, or a frame 1, rack guide 2, branch mechanism and moving platform 9 with the same structure are spliced ​​along the guide direction to realize multiple sets of parallel mechanisms working simultaneously.

[0030] It should be noted that it is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any figure mark in the claims should not be regarded as limiting the claims involved.

[0031] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A reconfigurable two-translation and two-rotation series-parallel hybrid mechanism, characterized in that: include A hollow rotating platform, on which a fixed base is installed; as well as A fixed base, the fixed base is fixedly connected to the frame; as well as A frame, wherein three parallel rack guide rails with unequal axis spacings are vertically provided on the front and two side surfaces of the frame, and the lateral spacing between the right rack guide rail of the frame and the front rack guide rail is twice the lateral spacing between the left rack guide rail and the front rack guide rail; and A branch mechanism, each of the rack guide rails is provided with a branch mechanism, the branch mechanism comprising a gear, a motor, a slider, a hinge 1, a rigid rod and a hinge 2; and A moving platform, wherein three hinge points are arranged on the moving platform, and the three hinges are respectively connected to the three hinge points on the bottom surface of the moving platform, and the bottom surface of the moving platform is used to install the end working tool; as well as The frame, the branch mechanism and the moving platform form a spatial parallel closed loop structure, the fixed base and the parallel mechanism form a serial-parallel hybrid mechanism, the rotating pair of the hollow rotating platform of the serial-parallel hybrid mechanism and the moving pairs in the three branch mechanisms are actively driven, so as to realize two translational and two rotational degrees of freedom of the serial-parallel hybrid mechanism; and For working environments at different heights, two or more racks can be spliced ​​along the guide rail direction, or racks, branches and moving platforms with the same structure can be spliced ​​along the guide rail direction to extend the working range along the height direction or allow multiple sets of parallel mechanisms to work simultaneously.

2. The series-parallel hybrid mechanism according to claim 1, characterized in that: The device can not only realize the independent operation of a serial-parallel hybrid mechanism, but also can be modularly spliced ​​according to the working environment at different heights. When two or more serial-parallel hybrid mechanisms are spliced ​​along the guide rail direction, the T-slots of the rack guide rails are sequentially butted, and the racks are connected by screws, thereby realizing the extension of the working range of the moving platform in the vertical direction.

3. From left to right, the rigid rods in the three branch mechanisms are rigid rod 1, rigid rod 2 and rigid rod 3, and rigid rod 1 and rigid rod 2 are short connecting rods of the same length, the length of rigid rod 3 is 1.5 times that of rigid rod 1, and the axes of hinge 1 and hinge 3 of the three rigid rods are parallel.

4. The moving platform of the series-parallel hybrid mechanism according to claim 1, characterized in that: The connecting lines of the three hinge points on the moving platform are arranged in a triangle, and hinge point one and hinge point three axes are coaxial. Hinge point one is located on the lower left side of the moving platform, hinge point two is located on the upper middle side of the moving platform, and hinge point three is located on the lower right side of the moving platform, which increases the stability of the moving platform during movement.

5. The orchard operation device of the serial-parallel hybrid mechanism according to claim 1 is characterized in that: Hinge 2 of the rigid rod 1 is connected to hinge point 1 on the bottom surface of the moving platform; hinge 2 of the rigid rod 2 is connected to hinge point 2 on the bottom surface of the moving platform; hinge 2 of the rigid rod 3 is connected to hinge point 3 of the moving platform.

Images