CN115781640A - Parallel manipulator - Google Patents

Abstract

The invention discloses a parallel manipulator, which comprises a base used as an installation foundation and an executing piece arranged at the tail end and used for grabbing articles, wherein two groups of moving branched chains mainly consisting of connecting rods are arranged on the base in parallel and are connected with the executing piece. The invention has the advantage that the range of motion of the article in the plane of movement can be increased in a simpler manner.

Description

A parallel manipulator

This application is a divisional application of the patent "A Method for Using a Manipulator to Control Plane Motion of Objects" with application number 202111029305.1 and application date 2021-09-03.

technical field

The invention relates to the field of manipulators for production or logistics, in particular to a parallel manipulator.

Background technique

In product production lines and logistics conveying and sorting systems, it is usually necessary to use manipulators to realize the plane motion control of items, so as to realize the automation process of production control. Common planar movement control manipulators can be divided into series and parallel. Among the serial manipulators, the most common is the joint arm manipulator structure, that is, two or three arms are connected in sequence, and then a motor is installed on the rear arm to drive the front arm to achieve motion control in one direction of freedom. An executive part that can fix items is installed on the frontmost support arm. The multi-section support arm combination can realize the motion control of the end effector in three-dimensional space. When working, the object to be moved is picked up and fixed by the actuator, and then the movement of each arm is controlled by the motor to realize the movement control of the object.

This tandem manipulator has the advantages of simple and classic structure, stable and reliable control, large movement space and less singularity (cannot reach the position point) inside the working space. However, the open-loop kinematic chain of the tandem manipulator makes the structure more complex and the motion control accuracy is low; and each joint of the tandem manipulator needs to be installed with a driving device, so its own weight is relatively large, and the inertia of motion is relatively large. It is beneficial to control, and increases energy consumption and costs. Therefore, the tandem manipulator is usually suitable for use in occasions where the mass and volume of the object to be moved is large, the range of the moving space is large, and the accuracy of the moving position is low.

For the movement control of items that mainly translate on a fixed plane, and the mass and volume of the moved object is small, and the accuracy of the movement position is high, it is more likely to use parallel manipulators for plane movement control. Parallel manipulators usually use parallel linkage mechanisms to form multiple sets of kinematic branch chains, and each group of kinematic branch chains drives the end effector to achieve translation control. It uses a closed-loop kinematic chain, and the kinematic chains of each group of components are independent of each other. The errors of the kinematic chain cancel each other out. This greatly improves the movement precision of the mechanism, and at the same time increases the overall rigidity and bearing capacity of the mechanism. In addition, due to the structural characteristics of the parallel manipulator, its driving device can be installed on the frame, which can reduce the weight of the component due to the driving device, reduce the weight of the kinematic chain of the mechanism, increase the movement speed and reduce the movement inertia.

However, the shortcomings of the parallel manipulator are also obvious. Since the parallel manipulator has more kinematic branch chains, the actual working space of the parallel manipulator is very small. The range of azimuth angles that need to be moved is relatively limited. Generally speaking, in a parallel manipulator, if you want to realize the movement control of the two degrees of freedom of the object in the X-axis and Y-axis directions on the same plane, you usually need at least two sets of motion branch chains, and at least five linkages can be connected to achieve control. For example, the two-degree-of-freedom spherical motion parallel mechanism disclosed in CN202011190090.7.

If it is necessary to realize the movement control of the object in the three directions of freedom of the X-axis and Y-axis and the rotation on the same plane, usually three sets of parallel motion branch chains are required, and at least seven connecting rods are required to realize the control. For example, a three-degree-of-freedom generalized spherical parallel mechanism disclosed in CN201910868664.2; a three-degree-of-freedom parallel mechanism applied to force feedback equipment disclosed in CN201810973840.4; A parallel mechanism with degrees of freedom; and a three-degrees-of-freedom parallel robot device disclosed in CN201921321553.1, and so on.

Therefore, for those skilled in the art, in the field of parallel manipulators to control the plane motion of objects, how to use fewer kinematic branches and connecting rods to achieve more degrees of freedom control of objects, and then better improve the objects in a simpler way. The flexibility of planar motion control has been a research direction.

Contents of the invention

Aiming at the deficiencies of the above-mentioned prior art, the technical problem to be solved by the present invention is: how to provide a method for controlling the plane movement of an article by using a manipulator that can better improve the movable range of the plane movement of the article in a simpler way and a Parallel manipulator.

In order to solve the problems of the technologies described above, the present invention adopts the following technical solutions:

A method of using a manipulator to control the plane movement of an object. In this method, a fixed object is grasped by an actuator, and then two sets of motion branch chains mainly composed of connecting rods installed on the base are used to control the actuator to realize the plane movement. It is characterized in that, through the self-rotation transmission mechanism attached to the kinematic branch chain, while the two sets of kinematic branch chains control the planar movement of the actuator, it drives the actuator to rotate synchronously.

In this way, while the two sets of motion branch chains of the parallel manipulator drive the planar movement of the actuator (displacement along the X-axis and Y-axis direction), at the same time, rely on the rotation transmission mechanism attached to the motion branch to drive the actuator to rotate synchronously, so that During the process of being grasped and translated, the direction can be further adjusted, and a degree of freedom control along the Z-axis rotation is added. Therefore, the azimuth range of item plane movement control is greatly improved. At the same time, this method combines the respective advantages of series-parallel manipulators. Since this method is mainly based on two sets of series-type kinematic branch chains to realize control, it has the advantages of simple structure, high motion precision, low energy consumption and low cost of parallel manipulators. At the same time, the function of controlling the rotation of objects is added through the self-rotation transmission mechanism attached to the motion branch chain, so it has the advantages of flexible control of the tandem manipulator and a larger controllable range of motion. Therefore, the advantages of the two manipulators in series and parallel can coexist and their disadvantages can complement each other. It greatly expands the types of manipulator control methods.

Further, a set of self-rotation transmission mechanisms are respectively attached to the two sets of kinematic branch chains and drive the actuators to rotate.

In this way, an extra set of self-rotation transmission mechanisms can well realize the redundant drive mode, which can improve the singularity of the mechanism in the working space, and can better cross over and change the singular configuration during the movement process, reducing the singularity of the actuator point, improve the practicality of the application.

Further, the method is implemented by a parallel manipulator, which includes a base as the installation base and an actuator set at the end for grabbing items, and two sets of them are installed side by side on the base The motion branch chain mainly composed of connecting rods is connected with the actuator, wherein, the actuator is installed vertically on an actuator rod, and the two ends of the actuator rod are respectively connected to the front ends of two groups of motion chains rotatably, and at least one set of attachments is also included. For the rotation transmission mechanism of any motion branch chain, the rotation transmission mechanism is used to drive the executive connecting rod to perform synchronous rotation movement.

In this way, when the manipulator is in use, relying on the two sets of link-type kinematic branch chains installed in parallel, it can drive the executive link to do translational movement along the X-axis and Y-axis in the plane, so that the actuator on the executive link can move in the X-axis and Y-axis on the plane. Degree of freedom control in the Y-axis direction; at the same time, relying on the autorotation transmission mechanism can further drive the execution link to perform synchronous rotation, so that the degree of freedom control of the execution member on the execution link along the Z-axis rotation on the plane is realized by means of serial transmission. Therefore, the present invention combines the advantages of the tandem manipulator and the parallel manipulator and complements the disadvantages, and has the characteristics of small error, high precision and large range of moving space angles of the grasped objects.

Further, each group of motion branch chains includes a driving rod and a driven rod, one end of the driving rod is vertically fixedly connected to the output shaft of a motion motor fixed on the base, and the other end of the driving rod is vertically arranged The first rotating joint (that is, the rotating shaft) is rotatably connected to one end of the driven rod, and the other end of the driven rod is rotatably connected to one end of the execution link through the second rotating joint arranged in the vertical direction; the driven rods of the two sets of motion branch chains They are respectively connected to the two ends of the connecting rod; the output shaft of the motion motor, the first rotary joint and the second rotary joint are all arranged in parallel; one end of the self-rotation transmission mechanism is installed on the base, and the other end is connected to the driven rod And it can drive the driven rod to rotate around the first rotating joint.

In this way, the two sets of kinematic branch chains together with the base and the execution link constitute a closed single kinematic chain, which can realize the movement of the execution link on a plane perpendicular to each joint through two motion motors through their respective kinematic branch chains. Freedom of movement control in the X-axis and Y-axis directions. At the same time, in this process, the driven rod can be driven to rotate around the first rotary joint through the rotation transmission mechanism, thereby changing the angle between the driven rod and the executing link, so that the executing link originally moves in translation along the X-axis and Y-axis On the basis of the above, a rotation motion is added, and then the three-degree-of-freedom motion control of X-axis translation, Y-axis translation and Z-axis rotation is realized. The actuating link member provided therein makes it possible to drive the actuator on it to move in a plane through the actuating link member, and at the same time facilitate the transmission of the transmission of the rotation transmission mechanism to the end of the actuating link, and then drive the actuator to rotate, Realize the rotational degree of freedom control on the Z axis. Therefore, on the basis of the conventional five-link two-degree-of-freedom parallel manipulator, this structure only adds one link, and only uses two-movement branch chain six-links to realize the control and adjustment of three degrees of freedom. The degree of freedom adjustment parallel manipulator reduces the number of motion branches, reduces the number of connecting rods, greatly simplifies the structure, avoids the constraints on the range of motion caused by too many branch chains, and increases the working space of the device.

As an optimization method of the self-rotation transmission mechanism, the self-rotation transmission mechanism includes a self-rotation motor installed on the base, the self-rotation motor and the corresponding motion motor are coaxially arranged, and the self-rotation motor passes through the belt transmission mechanism and the corresponding first rotation The ends of the driven rod at the joint are connected and drive the driven rod to rotate around the first rotating joint.

In this way, the belt-type transmission mechanism is adopted, and the driven rod is directly driven by the motor to rotate around the first rotating joint through the belt-type transmission mechanism, which has the characteristics of simple structure, convenient installation and easy implementation. Among them, the self-rotating motor is installed on the base, which will not occupy the mass of the moving parts, so that the overall device has a light structure, flexible and fast control, and low energy consumption in operation. However, the disadvantage is that the belt transmission mechanism may lack control accuracy due to slipping. It is suitable for control places that do not require too high precision but require a large controllable range.

Further, the belt transmission mechanism is a belt transmission mechanism, including a first pulley installed on the output shaft of the self-rotating motor and a second pulley fixed on the end of the driven rod and coaxially arranged with the first rotary joint.

This structure is simple and classic, and the cost is low, which is beneficial to implementation. However, other belt-type transmission mechanisms may also be used during specific implementation, such as chain sprocket transmission mechanisms and synchronous belt transmission mechanisms.

As another optimization method of the autorotation transmission mechanism, the autorotation transmission mechanism includes an autorotation motor installed on the base, the autorotation motor and the corresponding motion motor are coaxially arranged, and the output shaft of the autorotation motor is vertically fixed with a first The other end of the first autorotation transmission link is rotatably connected to the second autorotation transmission link through a third rotation joint arranged in a vertical direction, and the other end of the second rotation transmission link is rotatably connected through a fourth rotation joint arranged in a vertical direction. The joint is rotatably connected to the middle part of the corresponding follower rod and surrounds a parallelogram.

In this way, the parallelogram four-bar linkage mechanism is adopted, and the driven rod is driven by the motor to rotate around the first rotation joint through the first rotation transmission connecting rod and the second rotation transmission connection rod, which has the advantages of simple structure, convenient setting, high precision and high transmission reliable features. Among them, the self-rotating motor is installed on the base, which will not occupy the mass of the moving parts, so that the overall device has a light structure, flexible and fast control, and low energy consumption in operation. But the disadvantage is that the structure is relatively complex, and it is easier to cause the controllable range of motion to become smaller due to interference. It is suitable for control places that require high precision but less controllable range.

As another optimization method of the autorotation transmission mechanism, the autorotation transmission mechanism includes a telescopic cylinder, one end of the telescopic cylinder is rotatably installed on the output shaft of the corresponding motion motor, and the other end passes through the rotating joint and the middle part of the corresponding driven rod. Swivel connection. Wherein the telescopic cylinder can adopt structural modes such as electric cylinder or hydraulic telescopic cylinder or air cylinder. This can also drive the driven rod to rotate around the first rotary joint. However, the telescopic cylinder has a large dead weight, which will increase the structural quality of the movable part of the mechanism, which is not conducive to reducing energy consumption.

As an optimization, the self-rotation transmission mechanism is divided into two groups and respectively corresponding to two groups of motion branch chains.

In this way, after adding a group of self-rotation transmission mechanisms, the added self-rotation motor can be used as a driving device to help the actuator and the grasped item to cross the singularity point during the movement process. The whole mechanism can be driven redundantly, and the singularity of the mechanism in the working space can be improved through the redundant driving method, and the redundant drive can be used to make the mechanism cross the singularity when encountering a singularity during the movement.

Further, the actuator is a cylinder vertically installed and fixed in the middle of the actuator connecting rod, a telescopic rod is installed on the cylinder along the axial direction and a vacuum suction cup is installed at the front end of the telescopic rod.

In this way, it is convenient to grab objects by adsorption, and the structure is simple, compact and light.

As an option, the output shafts of the rotation motor and the corresponding motion motor are arranged opposite to each other. Easy to implement.

As another option, any one of the self-rotation motor and the corresponding motion motor is a biaxial motor and the output shaft of the motor is hollow, and the other motor output shaft can be coaxially rotatably sleeved inside the output shaft, so that the two The motors form a series installation structure. In this way, it is convenient to apply to the situation where two motors need to be installed on the same side of the base.

Further, the connecting rods and the executing connecting rods in each group of kinematic branch chains are arranged alternately in a ladder shape.

In this way, it is possible to effectively avoid the interference generated when crossing the middle during the movement, and obtain a larger working space as much as possible.

Further, each connecting rod and the motion branch chain are arranged along the horizontal direction, and each motor is arranged along the vertical direction. In this way, it is possible to conveniently control the plane movement of the grasped item along the horizontal direction, which is more suitable for practical application.

Further, the driven rods on both sides of the actuating connecting rod are misplaced on the upper and lower sides of the actuating connecting rod, and the two driving rods are respectively installed under the corresponding driven rods.

In this way, the two driven rods are misplaced on the upper and lower sides of the executive connecting rod, and the driven rods are respectively located at the closest positions to the upper and lower ends of the executive connecting rod in the vertical direction and the distance is equal, so the driven rods on both sides drive the executive connecting rod. When the rod rotates, the adverse effect of the moment due to gravity can be minimized and the left and right sides are affected in a balanced manner; at the same time, the two driving rods are respectively installed below the corresponding driven rods, which can avoid interference as much as possible and make the two groups of motion support The movement motor of the chain is as close as possible in the height direction, which makes the overall structure more compact, the force is more scientific, and the adverse effect of gravity torque is lower.

Further, the motion motors of the two sets of motion branch chains are installed on corresponding separate bases, and when the driving rods in the two groups of motion branch chains rotate to the positions facing each other, the movement between the two first rotating joints The spacing is smaller than the length of the driven rod, but the distance from any first rotary joint to the other split base is longer than the length of the driven rod, and the length of the driven rod is longer than the length of the execution link.

In this way, when the two sets of motion branch chains drive the actuator link to move to a position between the two bases, the interference between the driven rod and the actuator link located below the actuator link can be relied on to make the actuator located below After the connecting rod is stopped, relying on another motion branch chain to drive the executing connecting rod to change the angle and orientation, and change the motion track, so that the executing connecting rod as a whole passes over the line position between the two split bases, realizing the left and right position of the connecting line. region crossing. And because the interference position between the executive link and the lower driven link is a fixed position, another motion branch chain drives the execution link to change the angle and orientation in the process, which is controllable, that is, the entire movement track of the executive link is still is within the controllable range. In this way, the interference is cleverly used, so that a large controllable range of motion is obtained in a small base installation space.

Therefore, the present invention can have the following beneficial effects: 1. Compared with the plane three-degree-of-freedom parallel robot, the present invention adopts a closed single kinematic chain mode, which can realize three-degree-of-freedom motion in the plane, and the overall mechanical structure is relatively simple. The total number of branch chains is reduced, and the interference between branch chains and branch chains is reduced, thereby increasing the working space of the mechanism. When a belt transmission mechanism is used for transmission, the motion performance and flexibility are improved. 2 Compared with the planar three-degree-of-freedom series robot, the present invention has a closed kinematic chain with stronger bearing capacity, reduces the motion error of each component, improves the motion accuracy of the entire mechanical arm, and the driving motor device is fixed on the base On the shelf, the motion inertia of the robot itself is reduced, and it has better dynamic performance and faster running speed. 3. The present invention is a six-bar mechanism, which adopts a parallel layout. Although there is no symmetry in the strict sense, the mechanism still has good isotropy. 4. The present invention adopts the coaxial drive mode, that is, placing the two servo motors symmetrically up and down or coaxially connected in series can reduce the occupation of the installation space. At the same time, the belt drive is used to reduce the weight of the connecting rod joint and the movement of the mechanism. Inertia improves the motion performance of the system, reduces interference and increases the working space of the overall mechanism. 5 Compared with the planar two-degree-of-freedom five-bar parallel robot, the present invention has three degrees of freedom in the plane and can realize more functions. 6. The present invention can realize the redundant driving mode, through which the singularity of the mechanism in the working space can be improved, and when a singular configuration is encountered during the movement, the redundant driving can be used to make the mechanism cross the singular configuration .

To sum up, the present invention has the advantage of being able to better improve the movable range of the plane motion of the object in a simpler manner.

Description of drawings

Fig. 1 is a schematic structural diagram of the first embodiment of the present invention.

Fig. 2 is a schematic structural diagram of the first embodiment.

Fig. 3 is a schematic diagram of the actuating link in the middle spanning position in the first embodiment.

Fig. 4 is a schematic structural diagram of the second embodiment of the present invention.

Fig. 5 is a schematic structural diagram of a third embodiment of the present invention.

Fig. 6 is a schematic structural diagram of the third embodiment.

Fig. 7 is a schematic structural diagram of a fourth embodiment of the present invention.

Detailed ways

The present invention will be further described in detail below in combination with specific embodiments.

In specific implementation: a method of using a manipulator to control the plane movement of an object. In this method, a fixed object is grasped by an actuator, and then two sets of motion branch chains mainly composed of connecting rods installed on the base are used to control the actuator. Planar motion is characterized in that, through the rotation transmission mechanism attached to the motion branch chain, while the two sets of motion branch chains control the planar movement of the actuator, it drives the actuator to rotate synchronously.

In this way, while the two sets of motion branch chains of the parallel manipulator drive the actuator to move in translation (displacement along the X-axis and Y-axis direction), at the same time, relying on the rotation transmission mechanism attached to the motion branch chain to drive the actuator to rotate synchronously, so that During the process of being grasped and translated, the direction can be further adjusted, and a degree of freedom control along the Z-axis rotation is added. Therefore, the azimuth range of item plane movement control is greatly improved. At the same time, this method combines the respective advantages of series-parallel manipulators. Since this method is mainly based on two sets of series-type kinematic branch chains to realize control, it has the advantages of simple structure, high motion precision, low energy consumption and low cost of parallel manipulators. At the same time, the function of controlling the rotation of objects is added through the self-rotation transmission mechanism attached to the motion branch chain, so it has the advantages of flexible control of the tandem manipulator and a larger controllable range of motion. Therefore, the advantages of the two manipulators in series and parallel can coexist and their disadvantages can complement each other. It greatly expands the types of manipulator control methods.

Wherein, a set of self-rotating transmission mechanisms are respectively attached to the two sets of motion branch chains and drive the actuators to rotate.

In this way, an extra set of self-rotation transmission mechanisms can well realize the redundant drive mode, which can improve the singularity of the mechanism in the working space, and can better cross over and change the singular configuration during the movement process, reducing the singularity of the actuator point, improve the practicality of the application.

Specifically, this method can be realized by the parallel manipulators in the following several specific embodiments.

For the first embodiment, see Figs. 1-3. A parallel manipulator, including a base 10 as the installation base (the base is not shown in Figure 1, the base can be a single base or a split base) and a base set at the end for grabbing The executive part 1 of the article is installed side by side on the base with two sets of kinematic branch chains mainly composed of connecting rods connected to the executive part 1, wherein the executive part 1 is vertically installed on one executive link 2, and the two The two ends are respectively rotatably connected to the front ends of two sets of kinematic branch chains, and at least one set of autorotation transmission mechanism attached to any one kinematic branch chain is included.

In this way, when the manipulator is in use, relying on the two sets of link-type kinematic branch chains installed in parallel, it can drive the executive link to do translational movement along the X-axis and Y-axis in the plane, so that the actuator on the executive link can move in the X-axis and Y-axis on the plane. Degree of freedom control in the Y-axis direction; at the same time, relying on the autorotation transmission mechanism can further drive the execution link to perform synchronous rotation, so that the degree of freedom control of the execution member on the execution link along the Z-axis rotation on the plane is realized by means of serial transmission. Therefore, the present invention combines the advantages of the tandem manipulator and the parallel manipulator and complements the disadvantages, and has the characteristics of small error, high precision and large range of moving space angles of the grasped objects.

Wherein, each group of motion branch chains includes a driving rod 3 and a driven rod 4, one end of the driving rod 3 is vertically fixedly connected to the output shaft of a motion motor 5 fixed on the base, and the other end of the driving rod 3 passes through The first rotating joint 6 (that is, the rotating shaft) arranged in the vertical direction is rotatably connected to one end of the driven rod 4, and the other end of the driven rod 4 is rotatably connected to one end of the actuator link 2 through the second rotating joint 7 arranged in the vertical direction; The driven rods of the two groups of motion branch chains are respectively connected to the two ends of the executive connecting rod 2; the output shaft of the motion motor 5, the first rotary joint 6 and the second rotary joint 7 are all arranged in parallel; one end of the rotation transmission mechanism Installed on the base, the other end is connected with the driven rod and can drive the driven rod to rotate around the first rotation joint.

In this way, the two sets of kinematic branch chains together with the base and the execution link constitute a closed single kinematic chain, which can realize the movement of the execution link on a plane perpendicular to each joint through two motion motors through their respective kinematic branch chains. Freedom of movement control in the X-axis and Y-axis directions. At the same time, in this process, the driven rod can be driven to rotate around the first rotary joint through the rotation transmission mechanism, thereby changing the angle between the driven rod and the executing link, so that the executing link originally moves in translation along the X-axis and Y-axis On the basis of the above, a rotation motion is added, and then the three-degree-of-freedom motion control of X-axis translation, Y-axis translation and Z-axis rotation is realized. The actuating link member provided therein makes it possible to drive the actuator on it to move in translation through the actuating link member, and at the same time facilitate the transmission of the transmission of the autorotation transmission mechanism to the end of the actuating link, and then drive the actuator to rotate, Realize the rotational degree of freedom control on the Z axis. Therefore, on the basis of the conventional five-link two-degree-of-freedom parallel manipulator, this structure only adds one link, and only uses two-movement branch chain six-links to realize the control and adjustment of three degrees of freedom. The degree of freedom adjustment parallel manipulator reduces the number of motion branches, reduces the number of connecting rods, greatly simplifies the structure, avoids the constraints on the range of motion caused by too many branch chains, and increases the working space of the device.

Wherein, the autorotation transmission mechanism includes an autorotation motor 8 installed on the base, the autorotation motor 8 is coaxially arranged with the corresponding motion motor, and the autorotation motor 8 passes through the belt transmission mechanism 9 and the corresponding first rotary joint 6. The ends of the driven rod are connected and drive the driven rod 4 to rotate around the first rotary joint 6 .

In this way, the belt-type transmission mechanism is adopted, and the driven rod is directly driven by the motor to rotate around the first rotating joint through the belt-type transmission mechanism, which has the characteristics of simple structure, convenient installation and easy implementation. Among them, the self-rotating motor is installed on the base, which will not occupy the mass of the moving parts, so that the overall device has a light structure, flexible and fast control, and low energy consumption in operation. However, the disadvantage is that the belt transmission mechanism may lack control accuracy due to slipping. It is suitable for control places that do not require too high precision but require a large controllable range.

Wherein, the belt transmission mechanism 9 is a belt transmission mechanism, including a first pulley installed on the output shaft of the self-rotating motor and a second pulley fixed on the end of the driven rod and coaxially arranged with the first rotary joint.

This structure is simple and classic, and the cost is low, which is beneficial to implementation. However, other belt-type transmission mechanisms may also be used during specific implementation, such as chain sprocket transmission mechanisms and synchronous belt transmission mechanisms.

Wherein, the actuator 1 is a cylinder vertically installed and fixed in the middle of the actuator connecting rod. A telescopic rod is installed on the cylinder along the axial direction and a vacuum suction cup is installed on the front end of the telescopic rod.

In this way, it is convenient to grab objects by adsorption, and the structure is simple, compact and light.

In this embodiment, the output shafts of the autorotation motor 8 and the corresponding motion motor 5 are arranged opposite to each other. Easy to implement.

Wherein, the connecting rods and the executing connecting rods in each group of motion branch chains are staggered and arranged in a ladder shape.

In this way, it is possible to effectively avoid the interference generated when crossing the middle during the movement, see Fig. 3, and obtain a larger working space as much as possible.

Wherein, each connecting rod and the motion branch chain are arranged along the horizontal direction, and each motor is arranged along the vertical direction. In this way, it is possible to conveniently control the plane movement of the grasped item along the horizontal direction, which is more suitable for practical application.

Wherein, the driven rods on both sides of the executive connecting rod are misplaced on the upper and lower sides of the executing connecting rod, and the two driving rods are respectively installed under the corresponding driven rods.

In this way, the two driven rods are misplaced on the upper and lower sides of the executive connecting rod, and the driven rods are respectively located at the closest positions to the upper and lower ends of the executive connecting rod in the vertical direction and the distance is equal, so the driven rods on both sides drive the executive connecting rod. When the rod rotates, the adverse effect of the moment due to gravity can be minimized and the left and right sides are affected in a balanced manner; at the same time, the two driving rods are respectively installed below the corresponding driven rods, which can avoid interference as much as possible and make the two groups of motion support The movement motor of the chain is as close as possible in the height direction, which makes the overall structure more compact, the force is more scientific, and the adverse effect of gravity torque is lower.

Among them, the motion motors of the two sets of motion branch chains are installed on the corresponding separated bases. When the driving rods in the two groups of motion branch chains rotate to the positions facing each other, the distance between the two first rotating joints It is less than the length of the driven rod, but the distance from any first rotary joint to the other split base is longer than the length of the driven rod, and the length of the driven rod is longer than the length of the execution link. See Figure 3.

In this way, when the two sets of motion branch chains drive the actuator link to move to a position between the two bases, the interference between the driven rod and the actuator link located below the actuator link can be relied on to make the actuator located below After the connecting rod is stopped, relying on another motion branch chain to drive the executing connecting rod to change the angle and orientation, and change the motion track, so that the executing connecting rod as a whole passes over the line position between the two split bases, realizing the left and right position of the connecting line. region crossing. And because the interference position between the executive link and the lower driven link is a fixed position, another motion branch chain drives the execution link to change the angle and orientation in the process, which is controllable, that is, the entire movement track of the executive link is still is within the controllable range. In this way, the interference is cleverly used, so that a large controllable range of motion is obtained in a small base installation space.

The second embodiment, compared with the first embodiment, the parallel manipulator of this embodiment is only different in the structure of the rotation transmission mechanism, and the rest of the structure is completely the same.

See Figure 4: In this embodiment, the autorotation transmission mechanism includes an autorotation motor installed on the base, the autorotation motor and the corresponding motion motor are arranged coaxially, and the output shaft of the autorotation motor is vertically fixed with a first autorotation transmission Connecting rod 11, the other end of the first autorotation transmission link 11 is rotatably connected to the second autorotation transmission link 13 through a third rotation joint 12 arranged in the vertical direction, and the other end of the second autorotation transmission link 13 is rotatably connected through a vertically arranged The fourth rotary joint 14 is rotatably connected to the middle part of the corresponding driven rod 4 and forms a parallelogram.

In this way, the parallelogram four-bar linkage mechanism is adopted, and the driven rod is driven by the motor to rotate around the first rotation joint through the first rotation transmission connecting rod and the second rotation transmission connection rod, which has the advantages of simple structure, convenient setting, high precision and high transmission reliable features. Among them, the self-rotating motor is installed on the base, which will not occupy the mass of the moving parts, so that the overall device has a light structure, flexible and fast control, and low energy consumption in operation. But the disadvantage is that the structure is relatively complex, and it is easier to cause the controllable range of motion to become smaller due to interference. It is suitable for control places that require high precision but less controllable range.

The third embodiment, referring to Fig. 5 and Fig. 6, compared with the second embodiment, the parallel manipulator of this embodiment is only different in that the said rotation transmission mechanism is divided into two groups and respectively corresponding to two groups of kinematic branch chains. In this way, after adding a group of self-rotation transmission mechanisms, the added self-rotation motor can be used as a driving device to help the actuator and the grasped item to cross the singularity point during the movement process. The whole mechanism can be driven redundantly, and the singularity of the mechanism in the working space can be improved through the redundant driving method, and the redundant drive can be used to make the mechanism cross the singularity when encountering a singularity during the movement.

At the same time, in this embodiment, any one of the motors in the self-rotating motor 8 and the corresponding motion motor 5 is a biaxial motor and the output shaft of the motor is hollow, and the other motor output shaft can be coaxially rotatably sleeved inside the output shaft. The two motors form a series installation structure. In this way, it is convenient to apply to the situation where two motors need to be installed on the same side of the base.

The rest of the structure of this embodiment is completely the same as that of the second embodiment, and will not be described in detail here.

The fourth embodiment, referring to Fig. 7, compared with the third embodiment, the parallel manipulator of this embodiment differs only in that the self-rotation transmission mechanism adopts the same belt transmission mechanism as the first embodiment; while the rest of the structure It is exactly the same as the third embodiment.

In addition, during implementation, the autorotation transmission mechanism can also adopt other structural methods. For example, the autorotation transmission mechanism includes a telescopic cylinder, one end of the telescopic cylinder is rotatably installed on the output shaft of the corresponding motion motor, and the other end passes through the rotating joint It is rotatably connected with the middle part of the corresponding driven rod. Wherein the telescopic cylinder can adopt structural modes such as electric cylinder or hydraulic telescopic cylinder or air cylinder. This can also drive the driven rod to rotate around the first rotary joint. However, the telescopic cylinder has a large dead weight, which will increase the structural quality of the movable part of the mechanism, which is not conducive to reducing energy consumption.

Therefore, the present invention can have the following beneficial effects: 1. Compared with the plane three-degree-of-freedom parallel robot, the present invention adopts a closed single kinematic chain mode, which can realize three-degree-of-freedom motion in the plane, and the overall mechanical structure is relatively simple. The total number of branch chains is reduced, and the interference between branch chains and branch chains is reduced, thereby increasing the working space of the mechanism. When a belt transmission mechanism is used for transmission, the motion performance and flexibility are improved. 2 Compared with the planar three-degree-of-freedom series robot, the present invention has a closed kinematic chain with stronger bearing capacity, reduces the motion error of each component, improves the motion accuracy of the entire mechanical arm, and the driving motor device is fixed on the base On the shelf, the motion inertia of the robot itself is reduced, and it has better dynamic performance and faster running speed. 3. The present invention is a six-bar mechanism, which adopts a parallel layout. Although there is no symmetry in the strict sense, the mechanism still has good isotropy. 4. The present invention adopts the coaxial drive mode, that is, placing the two servo motors symmetrically up and down or coaxially connected in series can reduce the occupation of the installation space. At the same time, the belt drive is used to reduce the weight of the connecting rod joint and the movement of the mechanism. Inertia improves the motion performance of the system, reduces interference and increases the working space of the overall mechanism. 5 Compared with the planar two-degree-of-freedom five-bar parallel robot, the present invention has three degrees of freedom in the plane and can realize more functions. 6. The present invention can realize the redundant driving mode, through which the singularity of the mechanism in the working space can be improved, and when a singular configuration is encountered during the movement, the redundant driving can be used to make the mechanism cross the singular configuration .

Claims (10)

1. A parallel manipulator, including a base as the installation base and an actuator set at the end for grabbing objects. Two sets of kinematic branch chains and actuators mainly composed of connecting rods are installed side by side on the base. It is characterized in that the actuator is installed vertically on an actuator link, and the two ends of the actuator link are rotatably connected to the front ends of two sets of motion branch chains, and at least one set of rotation transmission attached to any motion branch chain mechanism, and the rotation transmission mechanism is used to drive the executive connecting rod to perform synchronous rotation. 2. Parallel manipulator as claimed in claim 1, it is characterized in that, each group of kinematic branch chains comprises a driving rod and a driven rod, and one end of the driving rod is vertically fixedly connected to a motion motor fixed on the base. On the output shaft, the other end of the driving rod is rotatably connected to one end of the driven rod through the first rotating joint arranged in the vertical direction, and the other end of the driven rod is rotatably connected to one end of the execution link through the second rotating joint arranged in the vertical direction The driven rods of the two groups of motion branch chains are respectively connected to the two ends of the executive connecting rod; the output shaft of the motion motor, the first rotating joint and the second rotating joint are all arranged in parallel; one end of the rotation transmission mechanism is installed on the base On the seat, the other end is connected with the driven rod and can drive the driven rod to rotate around the first rotating joint. 3. Parallel manipulator as claimed in claim 2, it is characterized in that, described autorotation transmission mechanism comprises an autorotation motor that is installed on the base, and autorotation motor and corresponding movement motor coaxially arrange, and autorotation motor is driven by belt. The mechanism is connected with the end of the driven rod at the corresponding first rotating joint and drives the driven rod to rotate around the first rotating joint. 4. The parallel manipulator as claimed in claim 3, wherein the belt transmission mechanism is a belt transmission mechanism, comprising a first belt pulley installed on the output shaft of the rotation motor and a belt pulley fixed on the end of the driven rod. And the second pulley coaxially arranged with the first rotary joint. 5. The parallel manipulator as claimed in claim 2, wherein the rotation transmission mechanism comprises a rotation motor installed on the base, the rotation motor and the corresponding motion motor are arranged coaxially, and the output shaft of the rotation motor The first autorotation transmission link is vertically fixed, and the other end of the first autorotation transmission link is rotatably connected to the second autorotation transmission link through a third rotary joint arranged in a vertical direction, and the other end of the second autorotation transmission link is connected through a vertical The fourth rotary joint with direction setting is rotatably connected to the middle part of the corresponding driven rod and surrounds a parallelogram. 6. The parallel manipulator as claimed in claim 2, wherein the rotation transmission mechanism comprises a telescopic cylinder, one end of the telescopic cylinder is rotatably mounted on the output shaft of the corresponding motion motor, and the other end passes through the rotating joint and The middle part of the corresponding driven rod is rotatably connected. Wherein the telescopic cylinder can adopt structural modes such as electric cylinder or hydraulic telescopic cylinder or air cylinder. 7 . The parallel manipulator according to claim 2 , wherein the rotation transmission mechanisms are divided into two groups and respectively corresponding to two groups of kinematic branch chains. 8 . 8. The parallel manipulator according to claim 2, wherein the actuator is a cylinder vertically installed and fixed in the middle of the actuator connecting rod, a telescopic rod is installed in the axial direction on the cylinder and a vacuum suction cup is installed at the front end of the telescopic rod . 9. The parallel manipulator as claimed in claim 2, characterized in that, the output shafts of the rotation motor and the corresponding motion motor are relatively arranged; or any motor in the rotation motor and the corresponding motion motor is a biaxial motor and the output of the motor The shaft is hollow, and another motor output shaft is coaxially rotatably sleeved inside the output shaft, so that the two motors form a series installation structure. 10. The parallel manipulator as claimed in claim 4, characterized in that, each connecting rod and executing connecting rod in each group of kinematic branch chains are arranged in a stepped manner; Each connecting rod and motion branch chain are arranged along the horizontal direction, and each motor is arranged along the vertical direction; The follower rods on both sides of the executive connecting rod are misplaced on the upper and lower sides of the executive connecting rod, and the two driving rods are respectively installed under the corresponding driven rods; The motion motors of the two sets of motion branch chains are installed on the corresponding separate bases. When the prime movers in the two groups of motion branch chains rotate to the positions facing each other, the distance between the two first rotating joints is less than the distance between the two first rotation joints. The length of the driven rod is longer than the length of the driven rod, but the distance from any first rotary joint to the other split base is longer than the length of the driven rod, and the length of the driven rod is longer than the length of the execution link.

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