Rope-driven reducing type multi-finger grabbing mechanism

Abstract

The invention discloses a rope-driven reducing type multi-finger grabbing mechanism. The rope-driven reducing type multi-finger grabbing mechanism comprises a reducing mechanism, a grabbing unit and a servo control system, a connecting piece is arranged between the reducing mechanism and the grabbing unit; included angles are formed between the grabbing units; the reducing mechanism comprises a cross-shaped crank, a transmission connecting rod and a cross-shaped fixing frame; a sliding rail and a first servo motor are fixed to the cross-shaped fixing frame. A sliding block is arranged on the sliding rail; the grabbing unit comprises a servo motor, a servo motor fixing piece and a multi-joint grabbing actuator. A winch is mounted on an output shaft of the servo motor, and a flexible rope is wound on the winch; the multi-joint grabbing actuator comprises spherical hinge knuckles which are arranged in the length direction of the multi-joint grabbing actuator and provided with through holes, and flexible fingertips located at the tail end of the multi-joint grabbing actuator. A flexible fixing ring is arranged between every two adjacent knuckles; one end of the flexible rope penetrates through the through hole of the spherical hinge-shaped knuckle to be connected with the flexible fingertip. The robot grabbing mechanism is suitable for grabbing irregular objects, and the problem that the grabbing range of an existing robot grabbing mechanism is difficult to flexibly adjust is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of robotic grasping devices, and particularly to a cable-driven variable-diameter multi-finger grasping mechanism. Background Art

[0002] With the rapid development of robot technology, higher requirements are put forward for the flexibility, adaptability and reliability of the end grasping mechanism in the fields of industrial production, warehousing logistics, medical care and emergency rescue. Existing grippers have various forms, including rigid multi-joint manipulators, tendon-driven or cable-driven flexible hands, parallel grippers and multi-finger grippers, etc. However, there are still problems such as complex structure, high cost, difficult to flexibly adjust the grasping range, insufficient enveloping ability and compliance for irregular objects, and poor adaptability in special environments.

[0003] Although existing cable-driven or tendon-driven multi-finger grasping devices have certain compliance, they generally rely on multi-cable paths, multi-motors or multi-stage differential mechanisms to achieve multi-finger linkage control, resulting in complex overall structure, limited cable path layout, and high driving redundancy. The multi-cable system is prone to problems such as cable length drift, uneven tension, and friction loss during long-term operation, making it difficult to maintain a stable grasping posture, with high maintenance and replacement difficulty, and affecting the reliability in industrial sites or complex environments. In addition, such mechanisms generally adopt an independent driving mode, resulting in a large volume and complex control system, and are not suitable for scenarios with limited space or requiring modular replacement.

[0004] Existing mechanisms for realizing grasping range adjustment mostly adopt slide rail type, link type or electric telescopic type structures, and change the grasping diameter by frame movement or joint opening, but their adaptive ability is limited. For example, some variable-diameter grippers will significantly reduce the grasping ability while increasing the grasping range; some structures rely on multiple rigid hinges, resulting in complex assembly and maintenance, and it is difficult to balance large-range opening and closing and structural compactness. In addition, such variable-diameter mechanisms are usually integrated with the end finger part, resulting in inability to achieve rapid overall replacement under high-loss working conditions, making it difficult to be used as a low-cost consumable actuator.

[0005] For the compliant grasping of irregular objects, existing technologies have proposed various structures such as soft pneumatic hands, silicone fingers, segmented flexible fingers, etc. However, these structures still have deficiencies in manufacturing methods, material properties and service life. Pneumatic actuators require complex pipelines and air systems and are difficult to work stably in high-temperature or sharp-object environments; silicone-molded flexible fingers mostly rely on manual production, are prone to aging and tearing, and are difficult to achieve high-precision, multi-material composite preparation; segmented flexible drive structures are usually not integrally formed, and the joints are prone to damage and have inconsistent service lives. Generally speaking, the existing flexible finger mechanisms have high manufacturing costs, insufficient stability, and are difficult to achieve high-consistency mass production, which limits their engineering promotion.

[0006] In summary, existing gripping mechanisms still have significant limitations in terms of structural complexity, gripping range, compliance control, manufacturing cost, and adaptability to special environments. Especially in applications requiring wide-range diameter adjustment, compliant envelope gripping, modular maintenance, and low-cost, rapid replacement, neither traditional mechanical grippers nor common soft gripping mechanisms can simultaneously achieve the comprehensive performance of simple structure, high reliability, and engineerable deployment.

[0007] Therefore, it is necessary to propose a new type of gripping mechanism that, while ensuring sufficient degrees of freedom and gripping capacity, enables graded adjustment of the gripping range. It should also be simple in structure, easy to manufacture, low in cost, modularly replaceable and maintainable, and suitable for special environments, thereby improving the versatility and engineering application value of the robot end effector. Summary of the Invention

[0008] Purpose of the invention: In view of the technical defects existing in the prior art, the purpose of this invention is to overcome the problems of existing robot gripping mechanisms, such as difficulty in flexibly adjusting the gripping range, complex structure, high cost and unsuitability for use as consumable parts, and poor adaptability in special environments. The invention provides a cable-driven variable diameter multi-finger gripping mechanism with a compact structure, flexible adjustable gripping range, low cost and suitability for special occasions. This mechanism is suitable for stable gripping of irregular objects and applications in robotic arm end effectors.

[0009] Technical solution: To achieve the above objectives, the rope-driven variable diameter multi-finger gripping mechanism of the present invention includes a variable diameter mechanism, a gripping unit, and a servo control system; there is a connecting member between the variable diameter mechanism and the gripping unit; there is an included angle between the gripping units; the variable diameter mechanism drives the gripping unit to open or close.

[0010] The variable diameter mechanism includes a cross-shaped crank, a transmission connecting rod, and a cross-shaped fixed frame; a slide rail and a first servo motor are fixed on the cross-shaped fixed frame; a slider is on the slide rail; a slider fixing component is fixed on the slider; the output shaft of the first servo motor is connected to the cross-shaped crank; a ball bearing is connected between the cross-shaped crank and the transmission connecting rod; the other end of the transmission connecting rod is hinged to the slider fixing component; the transmission connecting rod drives the slider to reciprocate linearly along the slide rail through the slider fixing component.

[0011] The gripping unit includes a servo motor, a servo motor mounting bracket, and a multi-joint gripping actuator; a winch is mounted on the output shaft of the servo motor, and a flexible rope is wound on the winch; the slider is connected to the servo motor mounting bracket via a connector; the multi-joint gripping actuator is fixed below the servo motor mounting bracket.

[0012] The multi-joint gripper includes ball joints with through holes arranged along the length of the multi-joint gripper, and a flexible fingertip located at the end of the multi-joint gripper; there is a flexible retaining ring between adjacent joints; one of the adjacent ball joints has an annular receiving groove for engaging the flexible retaining ring; one end of a flexible rope passes through the through hole of the ball joint and is connected to the flexible fingertip.

[0013] The servo control system includes a host computer, a power module, a multi-channel servo controller, and a servo motor assembly, which drives the first servo motor and the servo motor.

[0014] The DC output of the power module is divided into a first branch and a second branch. The first branch is connected to the multi-channel servo controller after voltage regulation and filtering, and the second branch is connected to the servo motor group.

[0015] The host computer sends the target position, speed, and control mode commands of the servo motors in the servo motor group to the servo controller and receives feedback information.

[0016] One end of the flexible rope is integrally molded with the flexible fingertip.

[0017] A gripper mounting plate is installed below the servo motor mounting bracket, and the multi-joint gripper is connected to the gripper mounting plate.

[0018] The connector is a flat plate, which is an integral rigid plate used to structurally connect the variable diameter mechanism and multiple gripping units.

[0019] The flexible fingertip uses elastic materials or a coated structure and is an end effector that comes into direct contact with the object being grasped.

[0020] Multiple columns are set on the cross-shaped fixing frame, and the columns are connected to the robot's end effector.

[0021] The ball-joint shaped fingers are arranged along the length of the multi-joint gripper and are integrally formed from a rigid material.

[0022] Working principle: The variable diameter mechanism in this invention is located above the connector to achieve graded adjustment of the gripping range; each gripping unit is arranged below the flat connector and achieves envelope gripping of the target object through a rope-driven winch system.

[0023] The variable diameter mechanism is preferably a crank-slider type structure, including a driving component located at the center and several linkage components arranged in a cross shape. Each linkage component is connected to a slider that can slide along the slide rail. When the driving component is working, the rotational or oscillating motion of the driving component is converted into the sliding motion of each slider along the slide rail through the transmission of the crank, connecting rod and slider. This manifests as the synchronous opening or closing motion of the gripping units, thereby driving the gripping units connected below to perform symmetrical extension and retraction, changing the gripping range of the gripping actuator.

[0024] The connector is provided with a mounting surface for fixing the diameter changing mechanism and a connection hole for detachable installation of each gripping unit, so that the gripping unit can be assembled and replaced as an independent module, while ensuring the rigidity and positioning accuracy of the overall structure.

[0025] The servo motor mounting bracket in the gripping unit is installed below the flat connector to support and secure the servo motor and the flexible rope winch. One end of the gripping actuator mounting plate is connected to the servo motor mounting bracket, and the other end extends downward to securely mount the integrated rope-driven multi-joint gripping actuator. The servo motor is mounted on the servo motor mounting bracket, and its output shaft is connected to the flexible rope winch, driving the winch to rotate around its own axis to achieve the winding and unwinding of the flexible rope. One end of the flexible rope is wound and fixed to the winch, and the other end is connected to the integrated rope-driven multi-joint gripping actuator. Under the forward and reverse drive of the servo motor, the flexible rope applies tension in the corresponding direction to the multi-joint gripping actuator, thereby controlling the bending and straightening of the actuator to achieve the enveloping gripping and release of the target object.

[0026] The multi-joint gripper includes a flexible rope arranged around the periphery of the joints and running through the entire joint chain, several ball-joint joints, a flexible retaining ring positioned between adjacent joints and partially embedded in the next joint, and a flexible fingertip at the end. The flexible rope passes through each ball-joint joint along a predetermined path, applying tension to each joint during retraction and extension, and is the main force-transmitting element driving the bending and straightening of the joint chain. Several ball-joint joints are geometrically arranged continuously along the length of the actuator, forming an integral joint chain and providing rotational freedom between adjacent joints. The flexible retaining ring is positioned between adjacent joints, with both ends fixed to the fixed end point of the previous joint, and its lower part nearly annular and partially embedded in the annular receiving groove of the next joint, forming an elastic connection between adjacent joints and limiting relative rotation angles. The flexible fingertip, located at the end of the joint chain, is the end effector that directly contacts the object being gripped, employing a high-friction coefficient elastic material or a coated structure to increase the contact area and friction, thereby improving gripping stability.

[0027] This actuator is integrally printed using additive manufacturing with multi-material fused deposition modeling. The flexible fingertips, flexible retaining rings, and flexible cords are made of flexible materials (such as thermoplastic polyurethane elastomers), while the ball-joint phalanges are made of rigid materials (such as polylactic acid). By constraining adjacent ball-joint phalanges with the flexible retaining rings, an axially inseparable, restricted rotational relationship is formed between adjacent phalanges, resulting in a continuous finger-like structure with multi-degree-of-freedom bending capabilities. Thus, the multi-joint gripper actuator, driven by a single flexible cord, can achieve coordinated bending of each phalanx, maintaining sufficient compliance while controlling the motion trajectory and stiffness distribution of each phalanx, avoiding excessive twisting or instability, thereby achieving a compliant envelope gripping of the target object.

[0028] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0029] (1) The present invention adopts a transmission method of rope drive combined with winch, which reduces high-cost components such as multi-degree-of-freedom servo motors and precision reducers. The support structure and finger joints are made of plastic parts and lightweight metal parts. The whole machine is easy to assemble, has few parts, and low unit cost. Moreover, the multi-joint gripping actuator is made of one piece and can be replaced as a whole as a vulnerable module, which is suitable for long-term use as a batch consumable item in harsh working conditions.

[0030] (2) The variable diameter mechanism provided on the connector of the present invention can drive multiple gripping units to open or close relative to each other, thereby changing the spacing between the actuators and the overall opening angle, realizing the graded adjustment of the gripping range, which can be quickly adjusted according to the target size without the need to replace different specifications of clamps, and the adaptability is significantly improved.

[0031] (3) By connecting the opposite ropes to both ends of the same winch, the present invention drives the multi-joint unit to bend in a coordinated manner, thereby achieving a high equivalent degree of freedom with reduced driving source action. At the same time, it can achieve enveloping compliant grasping of target objects of different shapes and postures, reducing the impact and local pressure on the grasped object. It has a high degree of freedom and good grasping compliance.

[0032] (4) The rope-driven variable-diameter multi-finger gripping mechanism adopted in this invention has a compact overall structure and light weight. The drive source can be centrally located away from dangerous or polluted areas. The claw part is mainly composed of passive rope drive and mechanical joints, with fewer electrical components, reducing the risk of failure in special environments such as high dust, high pollution, high corrosion, flammable and explosive, and confined spaces. In the event of pollution or damage, the end gripping unit or claw module can be quickly replaced as a whole, significantly improving system reliability and on-site maintenance efficiency. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of an embodiment of the rope-driven variable diameter multi-finger gripping mechanism of the present invention;

[0034] Figure 2 for Figure 1 A schematic diagram of the diameter-changing mechanism in a rope-driven variable-diameter multi-finger gripping mechanism.

[0035] Figure 3 for Figure 1 A schematic diagram of the gripping unit in a rope-driven variable-diameter multi-finger gripping mechanism;

[0036] Figure 4 for Figure 3 A schematic diagram of the structure of the multi-joint gripping actuator in the diagram;

[0037] Figure 5 for Figure 1 Schematic diagram of the control system of the mid-rope driven variable diameter multi-finger gripping mechanism;

[0038] Figure 6 for Figure 4 A schematic diagram of the software generation of a microscopic interlocking beam structure. Detailed Implementation

[0039] Figures 1 to 6 In the diagram, 1 is a flat connector; 2 is a variable diameter mechanism; 3 is a gripping unit; 2-1 is a cross-shaped crank; 2-2 is a ball bearing; 2-3 is a transmission connecting rod; 2-4 is a slider fixing part; 2-5 is a slider; 2-6 is a slide rail; 2-7 is a cross-shaped fixing frame; 2-8 is the first servo motor; 3-1 is a flexible rope winch; 3-2 is a servo motor; 3-3 is a servo motor fixing part; 3-4 is a gripping actuator fixing plate; 3-5 is a multi-joint gripping actuator; 3-1-1 is a flexible rope; 3-1-2 is a ball joint finger; 3-1-3 is a flexible fixing ring; 3-1-4 is a flexible fingertip; 4-1 is a host computer; 4-2 is a power module; 4-3 is a multi-channel servo controller; and 4-4 is a servo motor assembly.

[0040] like Figures 1 to 6 As shown, the rope-driven variable-diameter multi-finger gripping mechanism of the present invention comprises two parts: a mechanical body and a servo control system. The mechanical body includes a connector 1 located in the middle, a variable-diameter mechanism 2 disposed above the connector 1, and a plurality of gripping units 3 arranged below the connector 1. In this embodiment, the connector 1 is a flat plate connector.

[0041] The servo control system includes a host computer 4-1, a power supply module 4-2, a multi-channel servo controller 4-3, and a servo motor assembly 4-4.

[0042] The variable diameter mechanism 2 is used to drive each gripping unit 3 to open or close synchronously in the radial direction, so as to realize the graded adjustment of the gripping range; the gripping unit 3 realizes the compliant envelope gripping of the target object; the servo control system is used to uniformly control the first servo motor and the servo motors of each gripping unit.

[0043] like Figure 2 As shown, the diameter changing mechanism 2 is fixedly installed above the flat plate connector 1. The diameter changing mechanism 2 consists of a cross-shaped crank 2-1, a ball bearing 2-2, a transmission connecting rod 2-3, a slider fixing part 2-4, a slider 2-5, a slide rail 2-6, a cross-shaped fixing frame 2-7, and a first servo motor 2-8.

[0044] A cross-shaped crank 2-1 is connected to a transmission connecting rod 2-3 via a ball bearing 2-2. The transmission connecting rod 2-3 and the ball bearing 2-2 are interference-fitted. The other end of the transmission connecting rod 2-3 is hinged to each slider fixing component 2-4. The slider fixing component 2-4 is fixed to the slider 2-5, and the slider 2-5 can reciprocate linearly along the slide rail 2-6 set on the cross-shaped fixing frame 2-7. The lower end of the slider 2-5 is connected to the servo motor fixing component 3-3 in the gripping unit 3 via a flat plate connector 1.

[0045] The cross-shaped mounting bracket 2-7 is equipped with four columns for reliable connection to the robot's end effector flange. Threaded holes are provided on the cross-shaped mounting bracket 2-7 for reliable connection to the slide rail 2-6 and the first servo motor 2-8. The first servo motor 2-8 is mounted on the cross-shaped mounting bracket 2-7, and its output shaft is fixedly connected to the cross-shaped crank 2-1.

[0046] When the first servo motor 2-8 drives the cross-shaped crank 2-1 to rotate, through the geometric constraints of the transmission link 2-3 and the slider fixing part 2-4, it drives several sliders 2-5 to make synchronous and symmetrical linear movements in their respective slide rails 2-6: when the sliders 2-5 move outward, each gripping unit 3 opens outward accordingly, and the gripping range increases accordingly; when the sliders 2-5 move inward, each gripping unit 3 closes synchronously, and the gripping range decreases accordingly, thereby realizing the graded adjustment of the gripping range.

[0047] The flat plate connector 1 is an integral rigid plate used to structurally connect the variable diameter mechanism 2 and multiple gripping units 3.

[0048] like Figure 3 As shown, the gripping unit 3 includes a winch 3-1, a servo motor 3-2, a servo motor mounting bracket 3-3, a gripping actuator mounting plate 3-4, and a multi-joint gripping actuator 3-5.

[0049] The servo motor mounting bracket 3-3 is fixedly mounted on the lower surface of the flat plate connector 1-2 via a threaded connector, serving to support and fix the servo motor 3-2 and the winch 3-1. The servo motor 3-2 is mounted on the servo motor mounting bracket 3-3, with its output shaft extending out of the servo motor mounting bracket 3-3 and fixedly connected to the winch 3-1. The winch 3-1 is mounted on the output shaft of the servo motor 3-2 and rotates accordingly. The gripping actuator mounting plate 3-4 is fixed to the servo motor mounting bracket 3-3 via a threaded connector. Its upper end is arranged adjacent to the flat plate connector 1-2, and its lower end extends downward for mounting the multi-joint gripping actuator 3-5, thereby achieving a reliable connection between the multi-joint gripping actuator 3-5 and the flat plate connector 1-2 through the servo motor mounting bracket 3-3 and the gripping actuator mounting plate 3-4.

[0050] One end of the flexible rope is wound and fixed to the winch 3-1, and the other end is connected to the multi-joint gripper 3-5 via a predetermined path, which is used to apply tension to the multi-joint gripper 3-5 when the rope winch rotates. After the servo motor 3-2 is powered on, it drives the winch 3-1 to rotate around its own axis, thereby realizing the winding and unwinding of the flexible rope 3-1.

[0051] Servo motor 3-2 drives winch 3-1 to rotate in both directions, and transmits tension to multi-joint gripper 3-5 through the winding and unwinding of flexible rope 3-1-1, enabling it to bend and open, and achieve omnidirectional bending envelope gripping when multiple flexible ropes work together.

[0052] like Figure 4As shown, the multi-joint gripper 3-5 includes a flexible rope 3-1-1 arranged around the periphery of the phalanges and running through the entire phalanx chain, several ball-joint phalanges 3-1-2, a flexible retaining ring 3-1-3 positioned between adjacent phalanges and partially embedded in the next phalange, and a flexible fingertip 3-1-4 located at the end. The multi-joint gripper 3-5 is integrally printed using additive manufacturing with multi-material fused deposition modeling, wherein rigid and flexible materials are connected by an interlocking beam microstructure. The flexible rope 3-1-1 passes through the through holes on each ball joint 3-1-2 along a predetermined path, and is used to apply or release tension to each joint during retraction and extension. It is the main force transmission element that drives the bending and straightening of the joint chain. Multiple ball joints 3-1-2 are continuously arranged along the length of the actuator and are integrally formed from rigid material. They are used to form the overall joint chain and provide rotational freedom between each joint. The flexible fixing ring 3-1-3 is arranged between two adjacent joints 3-1-2 and is partially embedded in the annular receiving groove of the next joint. The two ends of the flexible fixing ring 3-1-3 are fixed to the two fixed ends corresponding to the previous joint through an additively manufactured interlocking beam microstructure, thereby realizing the elastic connection between the joints. The flexible fixing ring 3-1-3 is a circular ring with an open end. It can rotate within the annular groove when subjected to force. When it reaches the limit position of the ring, it restricts the relative rotation angle of adjacent ball joint finger 3-1-2. At the same time, it restricts the rotation of each ball joint finger 3-1-2 around the flexible rope 3-1-1, so that the finger joints can rotate within a predetermined range. The flexible fingertip 3-1-4 is located at the end of the finger chain and is the end actuator that directly contacts the object being grasped. In this embodiment, a high coefficient of friction elastic material or a coating structure is used to increase the contact area and friction, thereby improving the grasping stability.

[0053] In this embodiment, one end of the flexible rope 3-1-1 is integrally formed and fixed with the flexible fingertip 3-1-4, and the other end is connected to one or more winches 3-1 through a rope drive system. When the corresponding winch 3-1 rotates in one direction to retract the rope, the flexible rope 3-1-1 is tightened, and a tension force is applied to each ball joint 3-1-2 arranged along the line in sequence to make it bend in that direction, so that the ball joint 3-1-2 bends in sequence, thereby driving the finger chain to gradually bend to form an envelope gripping of the target object; when the winch 3-1 rotates in the opposite direction, the flexible rope 3-1-1 is pulled in the opposite direction, and a tension force opposite to the aforementioned bending direction is applied to each ball joint 3-1-2, so that each ball joint 3-1-2 gradually straightens towards the initial position, or bends in the opposite direction according to control requirements, thereby enabling the multi-joint gripping actuator 3-5 to achieve envelope gripping. Furthermore, when the rotation angles of the winches 3-1 corresponding to the two or more flexible ropes 3-1-1 arranged in different circumferential directions are different, the magnitude and direction of the tension generated by the flexible ropes 3-1-1 in different circumferential directions are different, so that the finger chain forms a resultant force in the circumferential direction, thereby enabling the multi-joint gripper 3-5 to bend in all directions and achieve omnidirectional compliant envelope gripping.

[0054] like Figure 5 As shown, the servo control system in this embodiment includes a host computer 4-1, a power supply module 4-2, a multi-channel servo controller 4-3, and a servo motor assembly 4-4.

[0055] The host computer 4-1 is connected to the multi-channel servo controller 4-3 via a wired communication interface (such as a serial port, USB to serial port, or Ethernet interface) to send instructions such as the target position, speed, and control mode of each servo motor to the servo controller 4-3, and to receive feedback status information.

[0056] The multi-channel PWM signal output terminals of the multi-channel servo controller 4-3 are connected to each servo motor in the servo motor group 4-4. The servo motor group 4-4 includes servo motor 1, servo motor 2, servo motor 3... servo motor n, which are used to drive the first servo motor 2-8 and the servo motor 3-2 in each gripping unit, respectively.

[0057] Power module 4-2 provides DC power to the multi-channel servo controller 4-3 and the servo motor assembly 4-4. The DC output of power module 4-2 is branched into two independent branches. One branch, after voltage regulation and filtering, connects to the multi-channel servo controller 4-3 to provide DC power to the control circuit. The other branch connects to the servo motor assembly 4-4 to provide DC power to each servo motor. By separating the control circuit branch and the power circuit branch on the same DC power supply and using filtering, voltage fluctuations and electromagnetic interference to the controller during high-current operation of the servo motors can be reduced, improving the control stability and reliability of the entire gripping mechanism during operation.

[0058] like Figure 6 As shown, the white portion is a rigid material, which in this embodiment uses polylactic acid (PLA); the black portion is a flexible material, which in this embodiment uses PLA thermoplastic polyurethane (PPP). Utilizing the layer-by-layer molding characteristic of additive manufacturing via multi-material fused deposition modeling, the rigid material and the flexible material are interlocked layer by layer until the two immiscible materials are tightly bonded together.

Claims

1. A rope-driven variable-diameter multi-finger gripping mechanism, characterized in that: It includes a diameter-changing mechanism (2), a gripping unit (3), and a servo control system; there is a connecting piece (1) between the diameter-changing mechanism (2) and the gripping unit (3); there is an included angle between the gripping units (3); the diameter-changing mechanism (2) drives the gripping unit (3) to open or close; The variable diameter mechanism (2) includes a cross-shaped crank (2-1), a transmission connecting rod (2-3), and a cross-shaped fixing frame (2-7); a slide rail (2-6) and a first servo motor (2-8) are fixed on the cross-shaped fixing frame (2-7); a slider (2-5) is on the slide rail (2-6); a slider fixing member (2-4) is fixed on the slider (2-5); the output shaft of the first servo motor (2-8) is connected to the cross-shaped crank (2-1); a ball bearing (2-2) is connected between the cross-shaped crank (2-1) and the transmission connecting rod (2-3); the other end of the transmission connecting rod (2-3) is hinged to the slider fixing member (2-4); the transmission connecting rod (2-3) drives the slider (2-5) to reciprocate linearly along the slide rail (2-6) through the slider fixing member (2-4); The gripping unit (3) includes a servo motor (3-2), a servo motor mounting bracket (3-3), and a multi-joint gripping actuator (3-5); a winch (3-1) is mounted on the output shaft of the servo motor (3-2), and a flexible rope (3-1-1) is wound on the winch (3-1); the slider (2-5) is connected to the servo motor mounting bracket (3-3) through the connector (1); the multi-joint gripping actuator (3-5) is fixed below the servo motor mounting bracket (3-3); The multi-joint gripper (3-5) includes ball joint-shaped fingers (3-1-2) with through holes arranged along the length of the multi-joint gripper (3-5), and a flexible fingertip (3-1-4) located at the end of the multi-joint gripper (3-5); there is a flexible fixing ring (3-1-3) between the adjacent fingers; one of the adjacent ball joint-shaped fingers has an annular receiving groove for engaging the flexible fixing ring (3-1-3); one end of the flexible rope (3-1-1) passes through the through hole of the ball joint-shaped finger (3-1-2) and is connected to the flexible fingertip (3-1-4).

2. The rope-driven variable-diameter multi-finger gripping mechanism according to claim 1, characterized in that: The servo control system includes a host computer (4-1), a power supply module (4-2), a multi-channel servo controller (4-3), and a servo motor group (4-4), which drives a first servo motor (2-8) and a servo motor (3-2).

3. The rope-driven variable-diameter multi-finger gripping mechanism according to claim 2, characterized in that: The DC output of the power module (4-2) is divided into a first branch and a second branch. The first branch is connected to the multi-channel servo controller (4-3) after voltage regulation and filtering, and the second branch is connected to the servo motor group (4-4).

4. The rope-driven variable diameter multi-finger gripping mechanism according to claim 2, characterized in that: The host computer (4-1) sends the target position, speed and control mode instructions of the servo motor in the servo motor group (4-4) to the servo controller (4-3) and receives feedback information.

5. The rope-driven variable diameter multi-finger gripping mechanism according to claim 1, characterized in that: One end of the flexible rope (3-1-1) is integrally formed with the flexible fingertip (3-1-4).

6. The rope-driven variable diameter multi-finger gripping mechanism according to claim 1, characterized in that: A gripper mounting plate (3-4) is installed below the servo motor mounting component (3-3), and the multi-joint gripper (3-5) is connected to the gripper mounting plate (3-4).

7. The rope-driven variable-diameter multi-finger gripping mechanism according to claim 1, characterized in that: The flexible fixing ring (3-1-3) is a circular ring with its end open.

8. The rope-driven variable-diameter multi-finger gripping mechanism according to claim 1, characterized in that: The flexible fingertip (3-1-4) is made of elastic material or has a coating structure.

9. The rope-driven variable diameter multi-finger gripping mechanism according to claim 1, characterized in that: Multiple columns are provided on the cross-shaped fixing frame (2-7), and the columns are connected to the robot end effector.

10. The rope-driven variable-diameter multi-finger gripping mechanism according to claim 1, characterized in that: The ball-joint phalanges (3-1-2) are arranged along the length of the multi-joint gripper and are integrally formed from a rigid material.

Images