Parallel robotic arm, parallel robot and plant topping equipment

Abstract

The present application provides a parallel robot arm, a robot and a plant topping device, which belongs to the technical field of industrial robots, and includes a frame, two articulated rod groups and an end effector; the two articulated rod groups are arranged in parallel and the motion ranges of the two articulated rod groups are in the same plane, one end of the two articulated rod groups is connected to the driving end of the corresponding driving motor, and the other end is hinged to the top of the end effector; the hinge point of the other end of the two articulated rod groups and the top of the end effector is the same hinge point. The parallel arrangement of the two articulated rod groups in the same motion plane can effectively reduce the structural volume, so that multiple groups are arranged in multiple parallel planes, and more parallel robot arms are arranged within a certain working range, which greatly improves the working efficiency. At the same time, the hinge points of the two articulated rod groups and the end effector are the same hinge point, so that when the articulated rod group moves with the end effector, the end effector naturally droops under the action of gravity to maintain the working state.

Description

Technical Field

[0001] The present application relates to the technical field of industrial robots, and in particular to a parallel robotic arm, a robot and a plant topping device. Background Art

[0002] Delta robot, also known as triangular robot, is a parallel robot among industrial robots. It is generally composed of three mechanical arms, universal joints and end effectors. The universal joints are located at the top, and the end effectors are located at the bottom of the robot. The three mechanical arms are connected in parallel between the universal joints and the end effectors. The main feature of the Delta robot is the use of a parallelogram structure on the mechanical arm, which can maintain the direction of the end effector. It has the advantages of strong load-bearing capacity, high rigidity, small deadweight-to-load ratio, and good dynamic performance.

[0003] Delta parallel robots can be used in many fields such as cargo sorting, high-speed handling operations and plant topping. However, the use of Delta parallel robots is limited due to their large structure and size, especially in the field of topping dense plants, such as cotton topping. Only a small number of Delta parallel robots can be arranged within a certain working range, resulting in low efficiency. In addition, Delta parallel robots have a complex structure and are expensive, making them unsuitable for popularization.

[0004] Chinese patent document CN103112000A discloses a two-degree-of-freedom translational parallel robot mechanism for high-speed handling operations, which consists of a frame, a moving platform and three branch chains. The first and second branch chains are exactly the same and consist of three rotating pairs with parallel axes. Among them, the two rotating pairs directly connected to the frame are set as active pairs, and a driving motor is installed. The third branch chain is a driven branch chain. The parallelogram mechanism constrains the moving platform to move in a translational manner. The first and second branch chains are driven branches, which constrain the rotational freedom of the moving platform. The prior art provides a parallel robot mechanism suitable for high-speed handling operations that only require two degrees of freedom translation, but the prior art is found to have the following defects in actual use: 1) First, the prior art adopts a double hinge point configuration. When the intermediate auxiliary component is removed, the mechanism will be uncontrollable and cannot be used. The intermediate auxiliary component used is a rigid part, which can only play a role in assisting the fixed end direction during the movement process. It does not provide any help to the load capacity of the mechanism, but becomes a part of the load; 2) Secondly, in order to control the output direction of the terminal moving platform, the intermediate auxiliary component adopts an active cylinder or a slide rail to assist the work. On the one hand, the working length of the active cylinder and the slide rail limits the movement range of the robot moving platform in the vertical direction (Z-axis direction). On the other hand, the active cylinder or the slide rail will greatly increase the control difficulty of the whole machine structure, reduce the structural stability, slow down the running speed, and increase the structural cost. The same is true for CN117001645A, which will not be introduced in detail here. Summary of the invention

[0005] The purpose of the present application is to provide a parallel robotic arm, a robot and a plant topping device, aiming to solve the problem that the Delta parallel robot in the related technology is limited in use due to its large structural volume. For example, in the field of cotton topping, only a small number of Delta parallel robots can be arranged within a certain working range, resulting in low efficiency. In addition, the Delta parallel robot has a complex structure, is expensive, and is not suitable for popularization.

[0006] Additional aspects and advantages of the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present application.

[0007] According to a first aspect of the present application, a parallel robot arm is provided, comprising a frame, two articulated rod groups and an end effector; wherein,

[0008] The frame is provided with two driving motors;

[0009] Two articulated rod groups are arranged in parallel and the motion ranges of the two articulated rod groups are in the same plane. One end of the two articulated rod groups is connected to the driving end of the corresponding driving motor, and the other end is hinged to the top of the end effector; the hinge point of the other end of the two articulated rod groups and the top of the end effector is the same hinge point;

[0010] An intermediate auxiliary component is located between the two articulated rod groups, one end of the intermediate auxiliary component is fixedly arranged relative to the frame, and the other end is connected to the top of the end effector, the connection point between the intermediate auxiliary component and the top of the end effector and the same hinge point are located in the same vertical direction, and the position of the connection point is higher than the position of the same hinge point; the intermediate auxiliary component is configured to apply a continuous upward pulling force along the axis direction of the intermediate auxiliary component to the end effector when the two articulated rod groups drive the end effector to move.

[0011] In an exemplary embodiment of the present application, the two articulated rod groups each include a first arm and a second arm, one end of the first arm is connected to the driving end of the corresponding driving motor, the other end of the first arm is hinged to one end of the second arm, and the other end of the second arm is hinged to the top of the end effector.

[0012] In an exemplary embodiment of the present application, the same hinge point is located at the center of the top of the end effector.

[0013] In an exemplary embodiment of the present application, the intermediate auxiliary component is an elastic member.

[0014] In an exemplary embodiment of the present application, the elastic member is a tension spring.

[0015] In an exemplary embodiment of the present application, the intermediate auxiliary component is an automatic wire pulling device, which includes a wire pulling device and an automatic wire winding structure. The automatic wire pulling device is fixed relative to the frame, and the free end of the wire pulling device is connected to the top of the end effector. The automatic wire winding structure applies continuous pulling force to the wire pulling device extending from the automatic wire pulling device.

[0016] In an exemplary embodiment of the present application, the automatic wire-winding structure includes a wire box, an intermediate gear, two synchronous gears and a spring structure, wherein the intermediate gear is located in the middle of the wire box, the two synchronous gears are horizontally symmetrically arranged on both sides of the intermediate gear and mesh with the intermediate gear, and the spring structure is applied to the intermediate gear or simultaneously applied to the two synchronous gears;

[0017] The pull wires are provided in two pieces, and both are steel wires, and the two steel wires are respectively retractably provided on the two synchronous gears;

[0018] The free ends of the two steel wires are respectively fixed to the two ends of a connecting rod in a horizontal direction, and the middle position of the connecting rod is fixedly connected to the top of the end effector;

[0019] The connecting rod is parallel to a center line connecting the two synchronous gears and a center line connecting the two driving motors.

[0020] In an exemplary embodiment of the present application, the fixing position of the one end of the intermediate auxiliary component is higher than the installation position of the driving motor on the frame.

[0021] According to a second aspect of the present application, there is provided a parallel robot, comprising the above-mentioned parallel robotic arm, wherein the frame is fixedly mounted on the mobile platform.

[0022] According to the third aspect of the present application, there is provided a plant topping device, comprising a mobile platform and a plurality of the above-mentioned parallel robotic arms, wherein the frames of the plurality of parallel robotic arms are fixedly mounted on the mobile platform and arranged side by side along the mobile platform; and the end effector is a cutter head module.

[0023] The exemplary embodiments of the present application may have some or all of the following beneficial effects:

[0024] In the parallel robot arm provided in the example implementation of the present application, it includes a frame, two articulated rod groups and an end effector, wherein two driving motors are provided on the frame, the two articulated rod groups are arranged in parallel and the motion ranges of the two articulated rod groups are in the same plane, one end of the two articulated rod groups is connected to the driving end of the corresponding driving motor, and the other end is hinged to the top of the end effector, and the hinge points of the two articulated rod groups and the end effector are the same hinge point. Firstly, the parallel arrangement of the two articulated rod groups in the same motion plane can effectively reduce the structural volume, so that multiple groups can be arranged in multiple parallel planes, and more parallel robot arms can be arranged within a certain working range, which greatly improves the working efficiency. At the same time, the hinge points of the two articulated rod groups and the end effector are the same hinge point, so that when the articulated rod groups move with the end effector, the end effector naturally droops under the action of gravity to maintain the working state.

[0025] Furthermore, in the parallel robotic arm provided in the example embodiment of the present application, an intermediate auxiliary part is arranged between the two articulated rod groups, and the intermediate auxiliary part is arranged to apply a continuous upward pulling force along the axis direction of the intermediate auxiliary part to the end effector when the two articulated rod groups drive the end effector to move. On the one hand, the setting of the intermediate auxiliary part greatly reduces the shaking of the end effector during the movement of the end effector. On the other hand, since the intermediate auxiliary part applies a continuous upward pulling force along the axis direction of the intermediate auxiliary part to the end effector, it itself will not become a load, but will increase the load capacity of the entire mechanism during high-speed operation.

[0026] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 A first structural schematic diagram of the parallel robotic arm in Example 1 of the present application is shown;

[0029] Figure 2 A second structural schematic diagram of the parallel robotic arm in Example 1 of the present application is shown;

[0030] Figure 3 The structure diagram of the automatic wire taking-up device in Example 1 of the present application is shown;

[0031] Figure 4 A plan view of the linkage mechanism formed by the parallel robotic arms in Example 1 of the present application is shown.

[0032] Description of reference numerals:

[0033] 1. Frame; 2. Driving motor; 3. First arm; 4. Second arm; 5. End effector; 6. Elastic member; 7. Hinge point; 8. Connection point; 9. Automatic wire-reeling device; 10. Pull wire; 11. Connecting rod; 12. Intermediate gear; 13. Synchronous gear; 14. Spring structure. DETAILED DESCRIPTION

[0034] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present application will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed descriptions will be omitted. In addition, the drawings are only schematic illustrations of the present application and are not necessarily drawn to scale.

[0035] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of the illustration to another component, these terms are used in this specification only for convenience, such as according to the direction of the examples in the drawings. It is understood that if the device of the illustration is turned upside down, the component described as "upper" will become the component "lower". When a structure is "on" other structures, it may mean that the structure is formed integrally on the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure through another structure.

[0036] The terms "a", "an", "the" and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express an open-ended inclusive meaning and mean that additional elements / components / etc. may exist in addition to the listed elements / components / etc.; the terms "first" and "second" are used merely as labels and are not intended to limit the quantity of their objects.

[0037] Delta robot, also known as triangular robot, is a parallel robot among industrial robots. It is generally composed of three mechanical arms, universal joints and end effectors. The universal joints are located at the top, and the end effectors are located at the bottom of the robot. The three mechanical arms are connected in parallel between the universal joints and the end effectors. The main feature of the Delta robot is the use of a parallelogram structure on the mechanical arm, which can maintain the direction of the end effector. It has the advantages of strong load-bearing capacity, high rigidity, small deadweight-to-load ratio, and good dynamic performance.

[0038] Delta parallel robots can be used in many fields such as cargo sorting, high-speed handling operations and plant topping. However, the use of Delta parallel robots is limited due to their large structure and size, especially in the field of topping dense plants, such as cotton topping. Only a small number of Delta parallel robots can be arranged within a certain working range, resulting in low efficiency. In addition, Delta parallel robots have a complex structure and are expensive, making them unsuitable for popularization.

[0039] The tandem SCARA (Selective Compliance Assembly Robot Arm) robot arm is a robot arm used for assembly operations. It has three rotating joints and is best suited for plane positioning. The SCARA system has compliance in the x and y directions and good rigidity in the Z axis direction. This feature is particularly suitable for assembly work. Common production line operations require additional Z-axis degrees of freedom at the end. The SCARA robot arm is characterized by a large workspace and high repeatability.

[0040] However, a single tandem SCARA robot arm cannot be used in many fields such as cargo sorting, high-speed handling operations and plant topping.

[0041] To this end, the present application proposes a parallel robotic arm and a parallel robot that are suitable for fields such as cargo sorting, high-speed handling operations and plant topping, and that occupy a small volume, have a simple structure, and are suitable for popularization.

[0042] Below, this article will introduce the parallel robotic arm, parallel robot and plant topping equipment of the present application by listing embodiments.

[0043] Example 1

[0044] This embodiment provides a specific implementation of the parallel robot arm. Figure 1 As shown, the parallel robot arm includes a frame 1, two articulated rod groups and an end effector 5. Two drive motors 2 are provided on the frame 1, and the drive motors 2 are used to drive the articulated rod groups for transmission; the two articulated rod groups are arranged in parallel and the motion ranges of the two articulated rod groups are in the same plane, that is, the motion direction of the articulated rod groups is a two-dimensional direction, one end of the two articulated rod groups is connected to the driving end of the corresponding drive motor 2, and the other end is hinged to the top of the end effector 5, and the hinge point 7 of the two articulated rod groups and the top of the end effector 5 is the same hinge point 7.

[0045] On the one hand, by arranging two articulated rod groups in parallel and setting the motion ranges of the two articulated rod groups to be in the same plane, the two articulated rod groups can be driven by two driving motors 2 respectively in the same plane (for example Figure 1 In the same vertical plane in the Cartesian coordinate system, the vertical plane is the xz plane) to move, thereby driving the other end of the two hinged rod groups ( Figure 1On the other hand, since the two articulated rod groups are arranged in parallel and the range of motion is in the same plane, the parallel robot arm of this embodiment occupies very little space in the direction perpendicular to the plane (y direction), especially compared with the Delta robot, it reduces the space occupation of one dimension, which is suitable for the scene of plane operation. Because the parallel robot arm of this embodiment occupies very little space in the y direction, multiple groups of the robot arms of this embodiment can be arranged in the y direction according to the actual application needs. When multiple groups of parallel robot arms are arranged side by side, their motion planes are parallel, and their respective work does not affect each other, which greatly improves the work efficiency.

[0046] In addition, it should be noted that the articulated rod group in this embodiment is similar to the serial SCARA robotic arm in the related art, and its structure retains the large working space and good rigidity in the y direction of the serial SCARA robotic arm. Compared with the serial SCARA robotic arm, the articulated rod group does not need to be equipped with an independent driving source on each arm body, and has a simple structure.

[0047] Therefore, the parallel robot arm of this embodiment, which combines the advantages of the Delta parallel robot and the serial SCARA robot arm, has the advantages of a large working space, high precision, strong load capacity and high speed.

[0048] In this embodiment, the two drive motors 2 are arranged side by side at the same horizontal position, that is, the two drive motors 2 have the same height. The advantage of such an arrangement is that the two articulated rod groups can be controlled more accurately and conveniently, and the kinematic algorithm of the parallel robot arm of this embodiment can be applied. Of course, it should be noted that this application does not limit the two drive motors 2 to be arranged at the same horizontal position. In other embodiments, the two drive motors 2 can also be arranged at different heights according to actual needs.

[0049] Furthermore, in this embodiment, the two articulated rod groups each include a first arm 3 and a second arm 4, one end of the first arm 3 is connected to the driving end of the corresponding drive motor 2, and the other end is hinged to one end of the second arm 4, and the other end of the second arm 4 is hinged to the top of the end effector 5. Among them, the most preferred articulated rod group is to use two arms. Under the drive of the drive motor 2, the first arm 3 rotates, and at the same time drives the second arm 4 to rotate, which is convenient for controlling the direction and position of the end of the second arm 4. If three or more arms are used, there are too many intermediate linkage links, and the end position of the articulated rod group is not easy to control.

[0050] In this embodiment, the hinge position between the two articulated rod groups and the top of the end effector 5 is located at the center of the top of the end effector 5. This arrangement allows the end effector 5 to naturally sag under its own gravity after the movement is completed, so that the end effector 5 can work at a better angle. Of course, in some other embodiments, the hinge position between the two articulated rod groups and the top of the end effector 5 may not be set at the center of the top of the end effector 5, but may be set on one side of the top center, leaving some deflection. At this time, after the end effector 5 is driven to move by the articulated rod group, the end effector 5 naturally sags under its own gravity. Since the hinge point 7 is located on the side of the top of the end effector 5, the end effector 5 will not sag to a vertical state, but will tilt at a certain angle. Through this arrangement, the end effector 5 can be suitable for some fixed scenes, such as the end effector 5 needs to maintain a certain angle to work normally. By adjusting the end fixing point of the elastic member 6, the swing amplitude of the end effector 5 during the entire movement process can be greatly adjusted.

[0051] For further lightweight design, the arm of the present embodiment may be hollowed out. The hollowed-out arm can not only further reduce the cost, but also facilitate the precise control of the end effector 5 and the improvement of the movement speed.

[0052] In this embodiment, an intermediate auxiliary component is arranged between the two articulated rod groups, one end of the intermediate auxiliary component is fixedly arranged relative to the frame 1, and the other end is connected to the top of the end effector 5, and the connection point 8 between the intermediate auxiliary component and the top of the end effector 5 and the same hinge point 7 of the articulated rod group are located in the same vertical direction, and the position of the connection point 8 is higher than the position of the hinge point 7. The intermediate auxiliary component is arranged to apply a continuous upward pulling force along the axis direction of the intermediate auxiliary component to the end effector 5 when the two articulated rod groups drive the end effector 5 to move. By setting the intermediate auxiliary parts, the shaking of the end effector 5 during the movement is greatly reduced, so that the end effector 5 can move to the working position in a smooth state, avoiding the need to wait for a long time for the end effector 5 to restore its own stability after the end effector 5 moves to the working position. For example, when the intermediate auxiliary parts are not added, the end effector 5 swings during the movement. After moving to the working position, the end effector 5 will swing along the hinge point 7 until the inertial force on the end effector 5 disappears after a period of time, the swinging ends, and the end effector 5 is in a natural drooping state before it can work. After the intermediate auxiliary parts are set, the shaking of the end effector 5 during the movement is slowed down due to the pulling of the intermediate auxiliary parts, so that the end effector 5 can move to the working position in a relatively smooth state. At this time, the time for waiting for the end effector 5 to recover is greatly shortened, so that the end effector 5 can enter the working state faster.

[0053] Furthermore, the intermediate auxiliary part and the frame 1 are relatively fixed, that is, one end of the intermediate accessory can be fixed on the frame 1, or extended to the top of the frame 1. At this time, the middle part of the intermediate auxiliary part is movably arranged with the bottom of the frame 1. The longer the length of the intermediate auxiliary part is, the smaller the amplitude of the shaking of the end effector 5 during the movement.

[0054] In this embodiment, Figure 1 As shown, the middle auxiliary part is an elastic member 6, which can apply elastic tension to the top of the end effector 5 during the movement of the end effector 5, so that the end effector 5 can remain as stable as possible during the movement. Furthermore, the elastic member 6 is configured as a tension spring, which provides tension to the end effector 5 when stretched by the end effector 5, so that the end effector 5 remains stable during the movement. The use of a tension spring to stabilize the direction of the end effector 5 greatly reduces the complexity of the overall structure. At the same time, the tension spring can provide tension during the movement of the parallel robot arm from bottom to top, thereby improving the load capacity of the parallel robot arm.

[0055] In some other embodiments, the elastic member 6 may also be a component with elastic force such as a spring or a bellows, as long as it has elastic tension when stretched and can provide tension for the end effector 5 .

[0056] In this embodiment, Figure 2 As shown, the intermediate auxiliary part can also be an automatic wire pulling device 10, which includes a wire pulling device 10 and an automatic wire taking-up structure, wherein the automatic wire pulling device 10 is relatively fixedly arranged with respect to the frame 1, the free end of the wire pulling device 10 is connected to the top of the end effector 5, and the automatic wire taking-up structure applies a continuous pulling force to the wire pulling device 10 extending from the automatic wire pulling device 10, and the pulling force applied by the automatic wire taking-up mechanism to the wire pulling device 10 can be transferred to the pulling force on the end effector 5, and the automatic wire taking-up device 9 can be arranged on the frame 1 or at other positions, but needs to pass through the frame 1, and the wire pulling device 10 needs to be located between two articulated rod groups. During the movement of the end effector 5, the end effector 5 can drive the wire pulling device 10 to extend, and after the wire pulling device 10 extends, the automatic wire taking-up structure begins to have a pulling force on the wire pulling device 10, and when the end effector 5 moves close to the frame 1, the automatic wire taking-up structure can retract the wire pulling device 10 into the automatic wire pulling device 10. The automatic wire-reeling device 9 is used to provide the pulling force for the end effector 5, which is not limited by the length of the spring and can adjust the extension length of the wire 10 at will according to the moving distance of the hinged rod group. The structure is simple and the use is convenient.

[0057] Furthermore, if Figure 3As shown, the automatic wire-winding structure includes a wire box, an intermediate gear 12, two synchronous gears 13 and a spring structure 14. The intermediate gear 12 is located in the middle of the wire box. The two synchronous gears 13 are horizontally symmetrically arranged on both sides of the intermediate gear 12 and mesh with the intermediate gear 12. The spring structure 14 is applied to the intermediate gear 12 or to the two synchronous gears 13 at the same time. The pull wire 10 is set as two steel wires, and the two steel wires are retractably arranged on the two synchronous gears 13, wherein, in the process of the pull wire 10 extending outward and retracting inward, the rotation angles of the two synchronous gears 13 are the same, that is, the two pull wires 10 extend to the same length, which can make the end effector 5 at the end of the pull wire 10 move more smoothly. Specifically, the two synchronous gears 13 are connected through the intermediate gear 12, and the two synchronous gears 13 rotate by meshing with the intermediate gear 12 to achieve the synchronous rotation of the two synchronous gears 13.

[0058] In this embodiment, the spring structure 14 is disposed on the two synchronous gears 13, and the spring structure 14 is applied to the synchronous gears 13 to achieve the same length of the two pull wires 10 extending outward and retracting inward. In some other embodiments, the spring structure 14 can also be applied to the middle gear 12, and the two synchronous gears 13 are retracted synchronously through the transmission of the middle gear 12.

[0059] The free ends of the two steel wires are respectively fixed to the two ends of a connecting rod 11 in the horizontal direction, the middle position of the connecting rod 11 is fixedly connected to the top of the end effector 5, and the connecting rod 11 is parallel to the center line of the two synchronous gears 13 and the center line of the two driving motors 2. When the pull wire 10 extends outward, the two pull wires 10, the center line of the two synchronous gears 13 and the connecting rod 11 form a parallelogram. No matter which direction the end effector 5 moves, the distance between the two synchronous gears 13 remains unchanged, the distance of the two pull wires 10 extending is the same, and the length of the connecting rod 11 remains unchanged. The parallelogram formed by them always maintains the same shape, and the connecting rod 11 always remains parallel to the line connecting the two synchronous gears 13, so that the end effector 5 keeps moving smoothly. The steel wire has a certain rigidity, which can ensure that the parallelogram does not deform, thereby ensuring the direction of the end effector 5.

[0060] In some other embodiments, one steel wire may be provided, one synchronous gear 13 is provided, and a clockwork structure 14 is provided on the synchronous gear 13. The provision of one steel wire is similar to that of the elastic component 6, but has the advantage of not being limited by the length of the elastic component 6.

[0061] In this embodiment, the fixed position of one end of the intermediate auxiliary part is higher than the installation position of the drive motor 2 on the frame 1, so that the length of the intermediate auxiliary part is longer. The longer intermediate auxiliary part can better slow down the swing amplitude of the end effector 5. When the swing angle of the end effector 5 is constant, the longer the length of the intermediate auxiliary part, the smaller the angle between the end effector 5 and the intermediate auxiliary part, that is, the swing amplitude of the end effector 5 is smaller.

[0062] In this embodiment, the main structure of the parallel robot arm is made of carbon fiber material, which reduces the overall structural mass as much as possible while ensuring strength, effectively reduces the moment of inertia of the overall movement; and increases the load capacity and operating speed. The parallel robot arm provided in this embodiment occupies less space in parallel compared to the serial robot arm. With the same working range and the same equipment space, several parallel robot arms can be arranged, which can not only greatly reduce the size of the topping robot, but also improve the topping efficiency by adding parallel robot arms.

[0063] In this embodiment, a kinematic analysis method of a parallel robot arm is also used to control and adjust the position of the end effector 5 by controlling the rotation angle of the drive motor 2 .

[0064] The algorithm for calculating the position of the end effector 5 based on the driving angle of the driving motor 2 is as follows: Figure 4 As shown in the figure, the parallel manipulator forms a five-bar linkage, where the bars AE, AB, BC, CD, and DE are named L 12 , L 23 , L 34 , L 45 , L 51 , the lengths of the rods are all known. In this embodiment, the lengths are respectively 0.3m, 0.4m, 0.4m, 0.3m, and 0.14m for illustration; ∠BAE, ∠CBF, ∠CDG, and ∠DEX are θ1, θ2, θ3, θ4, and θ5, A and E are the positions of the two drive motors 2, and C is the position of the end effector 5. A coordinate system is established with A as the origin and AE direction as the X-coordinate axis, as shown in FIG. Figure 4 As shown, the coordinates of point C are written through the left and right parts of the five-link, and the coordinates of point B are (X B , Y B ), the coordinates of point D are (X D , Y D ) to obtain the following equation:

[0065]

[0066] By calculation, we can get

[0067]

[0068] in,

[0069] A0=2L 23 (X D -X B )

[0070] B0=2L 23 (Y D -Y B )

[0071]

[0072] L BD =(X D -X B ) 2 +(Y D -Y B ) 2

[0073] By solving the equations, we can get the rectangular coordinates of point c (X C , Y C ):

[0074]

[0075] That is, the position coordinates of the end effector 5.

[0076] This embodiment also uses another kinematic analysis method of the parallel manipulator, which can obtain the rotation angle of the drive motor 2 through the position of the end effector 5. Figure 4 For example, when the coordinates of point C are known, θ = θ2-θ1, we can get:

[0077]

[0078] Square the above equation to get:

[0079]

[0080] Solving the above equation, we can get

[0081]

[0082] From this, the rotation angle θ1 of the drive motor 2 at point A can be obtained;

[0083] The same is true for the drive motor at point E, but it should be noted that when the coordinates of point C are obtained in the right half, the X coordinate needs to be subtracted from L. 51 ;

[0084] Assuming α = θ4-θ3, the solution of the equation of the drive motor at point E is:

[0085]

[0086] The above formula can be used to obtain the rotation angles θ1 and θ4 of the two drive motors 2. Through this analytical method, the rotation angles of the two drive motors 2 can be determined according to the position of the end effector 5. In actual use, taking cotton topping as an example, the position and angle of the end effector 5 are usually determined based on information such as the height and angle of the cotton top. The rotation angles of the two drive motors 2 are analyzed based on the position and angle of the end effector 5. In this way, it is only necessary to control the rotation angles of the two drive motors 2 to make the end effector 5 reach the cutting position corresponding to the cotton top.

[0087] Example 2

[0088] The embodiment of the present application provides a specific implementation of a parallel robot, including a mobile platform and the parallel robotic arm in Example 1. The frame 1 is fixedly mounted on the mobile platform, and the movement of the mobile platform drives the parallel robotic arm to move and work together.

[0089] Example 3

[0090] The embodiment of the present application provides a specific implementation of a plant topping device, including a mobile platform and multiple parallel robotic arms in Example 1, wherein the frames 1 of the multiple parallel robotic arms are fixedly mounted on the mobile platform and arranged side by side along the mobile platform, wherein the end effector 5 is a cutter head module.

[0091] In this embodiment, the plant topping equipment takes cotton topping as an example. Cotton is planted in multiple ridges during the planting process. During the growth of cotton, its top needs to be removed to achieve the purpose of promoting branch growth, controlling height and shape, etc. A plurality of parallel mechanical arms are arranged side by side on the mobile platform, and the motion planes of the articulated rod groups in the plurality of parallel mechanical arms are arranged in parallel. The mobile platform is erected on the cotton, and the parallel mechanical arms are hung downward, so that the cutter head module can move downward to the position of the cotton that needs to be toppled, and the top of the cotton is cut off. The parallel mechanical arms arranged side by side can top multiple cottons in a row at the same time. The mobile platform moves along the cotton ridge, and during the movement, the cutter head module tops the cotton.

[0092] Those skilled in the art will easily think of other embodiments of the present application after considering the specification and practicing the embodiments of the present application. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that the present application does not apply for. The specification and embodiments are only regarded as exemplary, and the true scope and spirit of the present application are pointed out by the appended claims.

Claims

1. A parallel robot arm, characterized in that: It includes a frame, two articulated rod groups and an end effector; wherein, The frame is provided with two driving motors; Two articulated rod groups are arranged in parallel and the motion ranges of the two articulated rod groups are in the same plane. One end of the two articulated rod groups is connected to the driving end of the corresponding driving motor, and the other end is hinged to the top of the end effector; the hinge point of the other end of the two articulated rod groups and the top of the end effector is the same hinge point; An intermediate auxiliary member is located between the two articulated rod groups, one end of the intermediate auxiliary member is fixedly arranged relative to the frame, and the other end is connected to the top of the end effector, and the connection point between the intermediate auxiliary member and the top of the end effector and the same hinge point are located in the same vertical direction, and the position of the connection point is higher than the position of the same hinge point; the intermediate auxiliary member is configured to apply a continuous upward pulling force along the axis direction of the intermediate auxiliary member to the end effector when the two articulated rod groups drive the end effector to move; The intermediate auxiliary component is an automatic wire pulling device, which includes a wire pulling device and an automatic wire taking-up structure. The automatic wire pulling device is fixedly arranged relative to the frame, the free end of the wire pulling device is connected to the top of the end effector, and the automatic wire taking-up structure applies a continuous pulling force to the wire pulling device extending from the automatic wire pulling device. The automatic wire-winding structure comprises a wire box, an intermediate gear, two synchronous gears and a spring structure, wherein the intermediate gear is located in the middle of the wire box, the two synchronous gears are horizontally symmetrically arranged on both sides of the intermediate gear and mesh with the intermediate gear, and the spring structure is applied to the intermediate gear or to the two synchronous gears at the same time; The pull wires are provided in two numbers, and the two pull wires are respectively retractably arranged on two synchronous gears; The free ends of the two pulling wires are respectively fixed to the two ends of a connecting rod in the horizontal direction, and the middle position of the connecting rod is fixedly connected to the top of the end effector; The connecting rod is parallel to a center line connecting the two synchronous gears and a center line connecting the two driving motors.

2. The parallel robot arm according to claim 1, characterized in that: The two articulated rod groups each include a first arm and a second arm, one end of the first arm is connected to the driving end of the corresponding driving motor, the other end of the first arm is hinged to one end of the second arm, and the other end of the second arm is hinged to the top of the end effector.

3. The parallel robot arm according to claim 1, characterized in that: The same hinge point is located at the center of the top of the end effector.

4. The parallel robot arm according to claim 1, characterized in that: The intermediate auxiliary member is an elastic member.

5. The parallel robot arm according to claim 4, characterized in that: The elastic component is a tension spring.

6. The parallel robot arm according to claim 1, characterized in that: The pull wires are all steel wires.

7. The parallel robot arm according to claim 1, characterized in that: The fixing position of the one end of the intermediate auxiliary member is higher than the mounting position of the driving motor on the frame.

8. A parallel robot, characterized in that: It comprises a mobile platform and the parallel robot arm described in any one of claims 1 to 7, wherein the frame is fixedly mounted on the mobile platform.

9. A plant topping device, characterized in that: It comprises a mobile platform and a plurality of parallel robotic arms according to any one of claims 1 to 7, wherein the frames of the plurality of parallel robotic arms are fixedly mounted on the mobile platform and arranged side by side along the mobile platform; and the end effector is a tool head module.

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