Multi-degree-of-freedom rope-driven discrete type robot arm

Abstract

The application discloses a multi-degree-of-freedom rope-driven discrete mechanical arm which is composed of a rope-driven mechanical arm, a rack and a rear sliding table; the rope-driven mechanical arm is composed of an end manipulator, an end guide rod, a middle guide rod, a tensile reset spring, an angular contact bearing, a bearing cover, a universal joint, a shifting block, a sliding rod, a guide flat key, a compression reset spring and a guide rod seat assembly; and the rack is composed of a frame body, a cradle mechanism, an electric slip ring, a transfer gear and a worm and gear mechanism. The circumferential rotation freedom of the cradle mechanism, the electric slip ring and the rope-driven mechanical arm around the main shaft is realized by controlling the stepping motor on the rack and transmitting through the worm and gear mechanism; the tension of two driving ropes is adjusted by the transfer gear through the stepping motor installed on the cradle mechanism, and the two shifting blocks are controlled to move on the sliding rod; the reset compression spring and the tensile reset spring jointly act, the sliding groove on the shifting block is matched with the sliding grooves on the front and rear parts of the middle guide rod, and the second to fifth rotation freedoms are provided.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of robots, more particularly, to a multi-freedom rope-driven discrete mechanical arm for complex space exploration and object retrieval, which provides a solution for realizing multi-freedom complex control using fewer motors and can be matched with different components to realize light-load grabbing, space exploration and other work tasks, and can be widely applied to industries such as pipeline operation and post-disaster rescue equipment. BACKGROUND

[0002] Emergency rescue after accidents and disasters is of great significance to reduce the loss of emergencies [2] A major cause of most losses is that the situation in the complex cavity caused by the earthquake cannot be timely explored, but the professional exploration equipment is expensive and complex to operate, and it is urgent to develop an exploration equipment based on advanced robot technology and relatively inexpensive and easy to use. Therefore, the present application proposes a multi-freedom wire-controlled discrete catheter mechanical arm controlled by a few motors, which can greatly reduce the high cost and complex control caused by multiple motors, and the wire-controlled system greatly improves the reliability and maintainability of the equipment. The present application can reduce the cost in hardware, software and operator training, thereby assisting post-disaster rescue and engineering projects carried out in complex space such as pipeline operation.

[0003] In the field of bionic robot design, according to the actuation principle of wire driving, combined with the design of slider and slot, the flexibility of the mechanical arm is greatly improved, and the number of required motors is reduced, meeting the work needs while reducing the manufacturing difficulty and cost. In the existing Chinese patent CN118061159A, a inflatable flexible manipulator is adopted, which uses rotary joints and flexible joints to improve the flexibility of the manipulator, and part of the structure uses winch and fine wire to improve the stiffness of the structure and realize reset operation. However, the structure design is complex, and the flexibility is limited, which cannot work in a small space. In Chinese patent CN117644501A, a foldable rope-pulling parallel robot for narrow space dexterous operation is disclosed, in which the wire-driven mechanical arm at the end has high flexibility and flexibility, but the joints are connected by compression springs, the precision is difficult to guarantee, and it is difficult to work under load. Chinese patent CN117415855A discloses a tendon type rope-driven mechanical arm, which uses a cross-shaped structure to improve the structural stiffness of the rope-driven mechanical arm, but its flexibility is low and the cost of four-motor control is high. SUMMARY

[0004] In order to solve the problems mentioned in the technical background, the purpose of the present application is to provide a mechanical arm with low cost, high flexibility and good rigidity, which can be widely applied to fields such as post-disaster rescue and pipeline operation.

[0005] The technical scheme of the present application is as follows: the mechanical arm is composed of a front conduit system, a rack system and a rear sliding table system, which are connected by driving ropes and serve as power transmission carriers.

[0006] The front mechanical arm is composed of a terminal guide rod, a middle guide rod, a push block, a universal joint and a base guide rod, etc., and when moving, the push block is driven by the rope to move backward, is clamped into the rear sliding groove in the guide rod, is limited in rotation by the universal joint to push the guide rod to rotate, and then moves the mechanical arm through the inclined plane at both ends of the guide rod. Similarly, when the tension of the thin rope decreases, the push block is reset by the compression spring, enters the front sliding groove, and makes the guide rod rotate further, so that the mechanical arm can work continuously. The middle guide rod and the terminal guide rod can both realize two rotational degrees of freedom around the center point of the universal joint, which can be controlled by the differential gear respectively.

[0007] Further, the base guide rod is rotated by the worm gear mechanism to realize the rotational degree of freedom of the mechanical arm around the main shaft, so that the five degrees of freedom of the mechanical arm are intermittently controlled by two motors.

[0008] Further, on the basis of the front mechanical arm, a rope-driven manipulator is integrated and installed on the terminal guide rod to realize the grabbing operation, and the matching rear sliding table system provides power for the driving rope of the manipulator through the sliding table to realize the gripping action.

[0009] The advantage effects of the present application are as follows:

[0010] 1. The present application provides a multi-degree-of-freedom rope-driven discrete mechanical arm, which has the advantages of low cost, high flexibility and good rigidity. The whole adopts rope-driven transmission, two motors are used to complete the five-degree-of-freedom control of the mechanical arm, and a sliding table realizes the grabbing of the manipulator, so that the cost and control cost are low.

[0011] 2. The present application has good adaptability, which is not limited to a single manipulator end effector, but can also be adapted to other modules such as a camera, and only needs to replace the end effector and the rear sliding table.

[0012] 3. The present application has excellent flexibility, and the five-degree-of-freedom mechanical arm can realize an approximately hemispherical reachable space, and the middle guide rod can further improve the flexibility by increasing the number of units, and can be applied to complex working environments. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a schematic view of a multi-degree-of-freedom rope-driven discrete mechanical arm of the present application.

[0014] Figure 2 is a cross-sectional view of a middle guide rod of a front mechanical arm of a multi-degree-of-freedom rope-driven discrete mechanical arm of the present application.

[0015] Figure 3 is a rear slider working schematic view of a multi-degree-of-freedom rope-driven discrete type mechanical arm of the present application.

[0016] Figure 4 is a front slider working schematic view of a multi-degree-of-freedom rope-driven discrete type mechanical arm of the present application.

[0017] Figure 5 is a top view sectional view of a multi-degree-of-freedom rope-driven discrete type mechanical arm of the present application.

[0018] Figure 6 is an end manipulator schematic view of a multi-degree-of-freedom rope-driven discrete type mechanical arm of the present application.

[0019] Figure 7 is a kinematic model of a multi-degree-of-freedom rope-driven discrete type mechanical arm of the present application.

[0020] Figure 8 is a reachable space schematic view of the present application in the case of a single middle guide rod and three middle guide rods.

[0021] Figure 9 is a motion state schematic view of a multi-degree-of-freedom rope-driven discrete type mechanical arm of the present application. DETAILED DESCRIPTION

[0022] The present application relates to the field of robots, in order to make the purpose, technical scheme and advantages of the present application more clear and explicit, the specific embodiments of the present application are described in detail below with reference to the drawings. It should be pointed out that, for those skilled in the art, without departing from the concept of the present application, a number of changes and improvements can be made. These all belong to the protection scope of the present application.

[0023] The technical scheme adopted by the present application is as follows: a multi-degree-of-freedom rope-driven discrete type mechanical arm is composed of a front mechanical arm, a rack and a rear slider (attached Figure 1 ), the three are connected by driving ropes and serve as the carrier of power transmission.

[0024] The front mechanical arm is composed of an end guide rod, a middle guide rod, a push block, a universal joint, a base guide rod, etc. (attached Figure 2 ), which is driven by the driving rope (attached Figure 5 ) to drive the push block to move backward, clamped into the rear sliding groove in the guide rod, and the rotation of the push block is limited by the universal joint to drive the guide rod to rotate (attached Figure 3 ), and the mechanical arm moves through the inclined plane at both ends of the guide rod. Similarly, when the driving rope tension decreases, the push block is reset by the compression spring, and enters the front sliding groove (attached Figure 4), so that the guide rod is further rotated, so that the mechanical arm can work continuously. The intermediate guide rod and the end guide rod can realize two rotation degrees of freedom θ2, θ3 and θ4, θ5 around the center point of the universal joint, which can be controlled by the transfer gear respectively.

[0025] Meanwhile, the base guide rod is rotated by the worm and gear mechanism on the frame to realize the rotation degree of freedom θ1 of the mechanical arm around the main shaft, so that the five degrees of freedom of the mechanical arm are intermittently controlled by two motors (appendix Figure 7 ). On the basis of the front mechanical arm, a rope-driven manipulator (appendix Figure 6 ) is integrated and installed on the end guide rod, so as to realize the grabbing operation. Meanwhile, the matched rear slide system provides power for the driving rope of the manipulator through the slide to realize the gripping action. Embodiment

[0026] The multi-degree-of-freedom rope-driven discrete mechanical arm is composed of a rope-driven manipulator, a frame and a rear slide, and the three are connected through a driving rope and serve as a power transmission carrier.

[0027] The specific implementation process of the present application is as follows:

[0028] When the system needs to be operated in a complex pipeline space, the first rotational degree of freedom of the front mechanical arm (I) and the cradle structure 2-14 is determined by the worm gear mechanism 2-16 through the stepping motor 1-1. Then the stepping motor 1-2 on the cradle structure 2-14 is controlled to rotate by a certain angle, the torque is increased through the gear set 5-4, the tension of the two driving ropes 5-2 is controlled by the transfer gear 5-5, one end of the driving rope is fixed on the marker block 2-8 by the clip 5-1, and the other end is fixed on the transfer gear 5-4. When the tension of the driving rope 5-2 increases, the two blocks 2-8 in the mechanical arm (I) move backward along the slide rod 2-9. When the block 2-8 moves backward by a certain stroke, it will be clamped into the rear sliding groove 3-1 of the middle guide pipe, and under the constraint of the sliding groove, the middle guide rod 2-3 is rotated and the mechanical arm (I) is moved. In this process, the asymmetrically distributed tension springs 2-4 around the guide pipe always contact the adjacent joints to maintain the normal operation of the mechanical arm. When the tension of the driving rope 5-2 decreases, the block 2-8 moves forward along the slide rod 2-9 under the pushing action of the compression spring 2-11. When the block 2-8 moves forward by a certain stroke, it will be clamped into the front sliding groove 4-1 of the middle guide pipe. Similarly, under the constraint of the sliding groove, the middle guide rod 2-3 is rotated and the mechanical arm (I) is moved to complete a rotation operation. When the end manipulator 2-1 of the mechanical arm reaches the specified working position, the stepping motor 1-3 is operated to move the sliding block 2-18 backward through the force amplification of the sliding table 2-17. The sliding block 2-18 is fixed with three manipulator driving ropes 5-3, and the other end of the driving rope is fixed on the finger 6-3 on the end manipulator through the clip 6-2. When the tension of the manipulator driving rope 5-3 increases, the finger 6-3 will be folded to the center under the constraint of the wrist 6-4, and the end of the finger 6-3 is provided with a friction pad 6-1 to increase the friction force during grabbing, thereby realizing the grabbing function. When the grabbed object needs to be placed, the sliding block 2-18 is moved forward to reduce the tension on the manipulator driving rope 5-3, and the reset torsional spring 6-5 resets the finger 6-3 to release the grabbed object.

[0029] The angle between the two end inclined planes of the middle guide rod 2-3 and the axis is 25 degrees, and the two inclined planes of each joint are closely fitted to realize a 50-degree deflection from the axis.

[0030] θ1∈[-180°, 180°]

[0031] θ2∈[-50°, 50°]

[0032] θ3∈[-50°, 50°]

[0033] θ4∈[-50°, 50°]

[0034] θ5∈[-50°, 50°]

[0035] and the mechanical arm link length is a=67.5mm, combined with the above data and the kinematics model, the reachable space of the two-joint five-degree-of-freedom and four-joint nine-degree-of-freedom mechanical arm can be solved (appendix Figure 8 ). The reachable space of the two-joint five-degree-of-freedom mechanical arm is approximately a hemisphere, and the reachable space of the four-joint nine-degree-of-freedom mechanical arm is approximately a sphere, both of which have excellent flexibility (appendix Figure 9 )

[0036] The specific embodiments of the present application are described above. It should be understood that the present application is not limited to the specific embodiments described above, and various changes or modifications can be made by those skilled in the art within the scope of the claims, which does not affect the essential content of the present application. In the case of no conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A multi-degree-of-freedom rope-driven discrete robotic arm, characterized by: The rope-driven mechanical arm, the frame and the rear slide table are composed; the rope-driven mechanical arm is located at the front of the frame, the end of the mechanical arm is fixed on the frame, and the rear slide table is fixed above the tail of the frame; The rope-driven mechanical arm is composed of an end manipulator, an end guide rod, a middle guide rod, a tensile reset spring, an angular contact bearing, a bearing cover, a universal joint, a block, a sliding rod, a guide key, a compression reset spring and a guide rod seat assembly; the guide rod seat is fixed on the frame, a middle guide rod penetrates through the middle of the guide rod seat, the middle guide rod is connected with the sliding rod through the universal joint, the middle guide rod is provided with the guide key, the block and the compression reset spring; the sliding rod is sleeved with the middle guide rod or the end guide rod outside, the middle guide rod is provided with the angular contact bearing and the bearing cover outside, the tensile reset spring is asymmetrically arranged on the bearing cover in the circumferential direction, and is connected with other guide rods; the end guide rod is provided with the end manipulator as an executing mechanism, and is used for realizing the grabbing function; The frame is composed of a frame body, a cradle mechanism, an electric slip ring, a transfer wheel and a worm and gear mechanism; the cradle mechanism is installed on the frame body, and is coaxially installed with the electric slip ring, so that signal transmission is facilitated; the cradle mechanism is driven by a stepping motor installed on the frame through the worm and gear mechanism, and realizes 360-degree rotation relative to the frame body; the cradle mechanism is further provided with a stepping motor, and the motor is provided with the transfer wheel, so that the tension of two driving ropes is independently adjusted; The rear slide table is composed of a slide table and a sliding block; the sliding block is fixedly installed on the slide table, and moves along the slide table relative to the frame under the drive of the slide table; the sliding block is concentrically installed with the guide rod seat, the cradle mechanism and the electric slip ring; Through control of the stepping motor on the frame, the worm and gear mechanism is driven to realize the circumferential rotation freedom of the cradle mechanism, the electric slip ring and the rope-driven mechanical arm around the main shaft, and has precise control capability; through the stepping motor installed on the cradle mechanism, the tension of the two driving ropes is adjusted by the transfer wheel, so that the movement of the two blocks on the sliding rod is respectively controlled; the reset compression spring and the tensile reset spring jointly realize the reset function; the sliding groove on the block cooperates with the sliding grooves on the front and rear of the middle guide rod, and provides the second to fifth rotation freedoms; finally, the tension of the manipulator driving rope fixed on the end guide rod is adjusted by the forward and backward movement of the sliding block on the slide table, so that the grabbing control of the end manipulator is realized.

2. The multi-DOF rope-driven discrete manipulator of claim 1, wherein, The rope-driven mechanical arm is driven by the driving rope to move the block, the block is clamped into the sliding grooves on the front and rear of the middle guide rod, so that the rope-driven mechanical arm and the end structure move; the sliding rod and the reset compression spring are arranged on the guide rod axis, the tensile reset spring is asymmetrically distributed outside the guide rod, and the driving rope penetrates through the sliding rod inside; the guide rod seat is fixedly installed on the frame, the middle guide rod penetrates through the center of the guide rod seat, and the middle guide rod is connected with the sliding rod through the universal joint; the guide key, the block and the compression reset spring are installed on the middle guide rod; the sliding rod can be sleeved with the middle guide rod or the end guide rod outside, the angular contact bearing and the bearing cover are installed on the middle guide rod outside, the tensile reset spring is asymmetrically arranged on the bearing cover in the circumferential direction, and is connected with other guide rods; the end guide rod is provided with the end manipulator as an executing mechanism, and realizes the grabbing function.

3. The multi-DOF rope-driven discrete manipulator of claim 1, wherein, The guide rod seat, the cradle mechanism, the electric slip ring, the worm gear and the sliding block are coaxially arranged on the frame to provide positioning and support, and the stepping motor controller is integrated; the frame is provided with a dovetail groove; the cradle mechanism and the electric slip ring are coaxially arranged on the frame body, facilitating signal transmission; the cradle mechanism is driven by the stepping motor through the worm gear and the worm mechanism to realize 360-degree rotation relative to the frame body; a stepping motor is further installed on the cradle mechanism and is provided with a differential gear to independently adjust the tension of the two driving ropes.

4. The multi-DOF rope-driven discrete manipulator of claim 1, wherein, The sliding table is powered and controlled by the stepping motor, the sliding table amplifies the force output, the sliding block can move forward and backward along the sliding table, thereby affecting the tension of the driving rope of the mechanical hand, and the end mechanical hand is controlled to be gripped.

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