Hydraulic joint driven multi-degree-of-freedom manipulator and control method thereof

Abstract

The invention relates to a multi-degree-of-freedom manipulator driven by hydraulic joints and a control method thereof. The manipulator is composed of n manipulator units, and each manipulator unit comprises a wrist joint and a finger joint. Wrist joints and finger joints; the wrist joint comprises a far finger end swinging oil cylinder, a far finger end swinging oil cylinder shaft, a near finger end swinging oil cylinder, a near finger end swinging oil cylinder shaft, a finger joint torsion bevel gear, a finger joint swinging bevel gear, a finger joint torsion base and a finger joint swinging bevel gear shaft; each knuckle comprises a lower knuckle, an upper knuckle and an adjustable pin shaft. The clamping angle of each finger joint is adjusted by controlling the far finger end swing oil cylinder; and the magnitude of the clamping force of the finger joints is adjusted by controlling the near finger tip swing oil cylinder. Compared with the prior art, the invention has the advantages of high flexibility, large torque range, good stability, modular design, compact structure and the like.

Description

Technical Field

[0001] The invention relates to the technical field of robots, and in particular to a multi-degree-of-freedom manipulator driven by hydraulic joints and a control method thereof. Background Art

[0002] The robot can imitate certain movements of human hands and arms, and grasp, carry objects or operate tools according to the program. It has the advantages of both humans and machines, not only reducing the burden on people, but also better protecting personal safety in harmful and dangerous environments. At present, the robot is widely used in machinery manufacturing, metallurgy, electronics, light industry and atomic energy industries.

[0003] As the execution end of the robot's interaction with the environment, the manipulator's working performance has a great impact on the robot's overall performance. Therefore, it is necessary to provide a manipulator with high flexibility, wide applicability, large torque range and high reliability.

[0004] There are many studies on manipulators. For example, the invention patent with publication number CN107053243A discloses an articulated robot gripper, which is driven by a DC motor and uses wire rope traction and springs to grasp and release parts. The three fingers move synchronously, but it cannot achieve completely autonomous independent control, and the multi-position slots embedded in the fingers can only select three angles, so its applicability is low.

[0005] In addition, the torque that the motor can provide through the wire rope is small, the structure is complex, and the transmission reliability is low. For example, a hydraulic manipulator disclosed in the utility model with publication number CN212241111U uses hydraulic pressure as the driving force, but its mechanical grip angle is not adjustable, and the two mechanical grips are in a linkage state, which makes it difficult to clamp and release spherical objects and irregular objects, and has poor applicability. Summary of the invention

[0006] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a multi-degree-of-freedom manipulator driven by a hydraulic joint and a control method thereof.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] According to one aspect of the present invention, a hydraulic joint multi-degree-of-freedom manipulator is provided, which consists of n manipulator units, n is a positive integer, each manipulator unit is assembled in a sleeve 3, and is fixedly connected to the inner bottom surface of the sleeve 3 via a base 4, and a single manipulator unit includes a wrist joint 1 and a finger joint 2; the wrist joint 1 includes a distal finger end swing cylinder 5, a distal finger end swing cylinder shaft 6, a proximal finger end swing cylinder 8, a proximal finger end swing cylinder shaft 9, a finger joint torsion bevel gear 10, a finger joint swing bevel gear 11, a finger joint torsion base 12 and a finger joint swing bevel gear shaft 13; the finger joint 2 includes a lower finger joint 14, an upper finger joint 15 and an adjustable pin shaft 16.

[0009] As a preferred technical solution, the distal finger end swing cylinder 5 and the proximal finger end swing cylinder 8 are both hydraulic swing cylinders.

[0010] As a preferred technical solution, in the wrist joint 1, the distal finger end swing cylinder 5 is fixedly connected to the base 4, and its output shaft is the distal finger end swing cylinder shaft 6, which is fixedly connected to the finger joint torsion base 12, and outputs torque under the push of hydraulic pressure to adjust the torsion angle of the finger joint 2; the proximal finger end swing cylinder 8 is connected to the top of the distal finger end swing cylinder 5 via the flange 7, and its output shaft is the proximal finger end swing cylinder shaft 9, which is fixedly connected to the finger joint torsion bevel gear 10, and outputs torque under the push of hydraulic pressure to adjust the swing angle of the finger joint 2.

[0011] As a preferred technical solution, the rotation direction of the knuckle torsion bevel gear 10 is consistent with the torsion direction of the knuckle 2; the knuckle swing bevel gear 11 is fixedly connected to the knuckle swing bevel gear shaft 13, and its rotation direction is consistent with the swing direction of the knuckle 2;

[0012] As a preferred technical solution, the finger joint torsion bevel gear 10 and the finger joint swing bevel gear 11 are meshed with each other to control the swing angle and speed of the finger joint.

[0013] As a preferred technical solution, the proximal finger end swing cylinder shaft 9 is a hollow output shaft, and the inner diameter of the hollow shaft is larger than the outer diameter of the distal finger end swing cylinder shaft 6 .

[0014] As a preferred technical solution, a ball double-helix hydraulic swing joint is used in the wrist joint 1.

[0015] As a preferred technical solution, the lower knuckle 14 and the upper knuckle 15 in the knuckle 2 are hinged by an adjustable pin 16, the lower knuckle 14 is fixedly connected to the knuckle swing bevel gear shaft 13, and the adjustable pin 16 is used to adjust the angle between the lower knuckle 14 and the upper knuckle 15.

[0016] As a preferred technical solution, the upper knuckle 15 and the lower knuckle 14 are each provided with an anti-slip pad 17 on the clamping side thereof to increase the friction coefficient.

[0017] According to another aspect of the present invention, a control method for a hydraulic joint multi-degree-of-freedom manipulator is provided, and the method is applied to a hydraulic joint multi-degree-of-freedom manipulator as described above. In the method, the distal finger end swing cylinder 5 is first controlled to make the distal finger end swing cylinder shaft 6 drive the finger joint twisting base 12 to twist, and then adjust the twisting angle, that is, the clamping angle, of each finger joint 2 to adapt to different part shapes and sizes; then the proximal finger end swing cylinder 8 is controlled to make the proximal finger end swing cylinder shaft 9 drive the finger joint twisting bevel gear 10 to rotate, at this time, the finger joint swing bevel gear 11 makes a fixed-axis rotation because the finger joint twisting base 12 is stationary, and then drives the finger joint swing bevel gear shaft 13 and the finger joint 2 to swing, so as to adjust the swing angle and speed of each finger joint 2, that is, adjust the clamping force of each finger joint 2.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The manipulator in the present invention includes n manipulator units, n is a positive integer, each manipulator unit is assembled in a sleeve and fixedly connected to the inner bottom surface of the sleeve via a base, and a single manipulator unit includes a wrist joint and a finger joint; the wrist joint includes a distal finger end swing cylinder, a distal finger end swing cylinder shaft, a proximal finger end swing cylinder shaft, a finger joint torsion bevel gear, a finger joint swing bevel gear, a finger joint torsion base and a finger joint swing bevel gear shaft, providing driving and control capabilities; the finger joint includes a lower finger joint, an upper finger joint and an adjustable pin shaft, providing clamping capabilities, and through the driving of the distal finger end swing cylinder and the proximal finger end swing cylinder and their control of the gear, i.e., the base, the control of the torsion and swing angle of the finger joint is achieved to complete the stable clamping process, and the combined action of the various components in the wrist joint enhances the stability of the manipulator.

[0020] 2. In the present invention, the distal finger end swing cylinder is first controlled to make the distal finger end swing cylinder shaft drive the finger joint twisting base to twist, and then adjust the twisting angle of each finger joint, i.e. the clamping angle, to adapt to different parts shapes and sizes; then the proximal finger end swing cylinder is controlled to make the proximal finger end swing cylinder shaft drive the finger joint twisting bevel gear to rotate, at this time, the finger joint swing bevel gear rotates along a fixed axis because the finger joint twisting base does not move, and then drives the finger joint swing bevel gear shaft and the finger joint to swing, so as to adjust the swinging angle and speed of each finger joint, i.e. adjust the clamping force of each finger joint. This makes the control method of the present invention simple and highly flexible.

[0021] 3. In the present invention, both the distal finger end swing cylinder and the proximal finger end swing cylinder are hydraulic swing cylinders. Since the torsion and swing of the finger joints are driven by the hydraulic swing cylinders and transmitted through the gear pairs and gear shafts, the torque range is large and the high stability of the hydraulic system can be fully utilized. The torque range is large and the stability is good.

[0022] 4. The number of manipulator units, the angle of the knuckles and the material of the anti-skid pads on the knuckles in the present invention can be replaced and adjusted according to the material, size and shape of the clamped object. The knuckles can be replaced according to the size, shape, material, etc. of the parts to better adapt to the clamped object; the anti-skid pads on the knuckles can be replaced according to the material of the clamped object; the manipulator claws are independent of each other, and their number can be adjusted according to user needs, such as two-hand claws, three-hand claws, four-hand claws and six-hand claws, etc. The angle and distance between the claws can be adjusted arbitrarily, just by replacing the wrist joint sleeve and the base of the fixed claws. Its components have good independence and can achieve modular design.

[0023] 5. In the present invention, the swing cylinder shaft at the proximal finger end is a hollow output shaft, and the inner diameter of the hollow shaft is larger than the outer diameter of the swing cylinder shaft at the distal finger end, thereby realizing the control of the torsion and swing of the finger joints on one axis, and adopting a ball double-helix hydraulic swing joint in the wrist joint, which further saves materials and space, making the structure compact and light. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of a three-claw manipulator in the embodiment;

[0025] Figure 2 A schematic diagram of a single gripper in the embodiment;

[0026] Figure 3 It is a left view of a single gripper in the present invention;

[0027] Figure 4 It is a cross-sectional view of a single gripper in the present invention along the AA direction;

[0028] Figure 5 Schematic diagram of a four-claw manipulator in an embodiment of the present invention;

[0029] Figure 6 Schematic diagram of a two-handed claw manipulator in an embodiment of the present invention;

[0030] Figure 7 This is a schematic diagram of a three-claw robot gripping a column;

[0031] Figure 8 It is a top view schematic diagram of a three-claw manipulator gripping a column;

[0032] Fig. 9 This is a schematic diagram of a three-claw manipulator holding a spherical object;

[0033] Fig.10 It is a top view schematic diagram of a three-claw manipulator holding a spherical object;

[0034] In the figure, 1 is the wrist joint; 2 is the finger joint; 3 is the sleeve; 4 is the base; 5 is the distal finger end swing cylinder; 6 is the distal finger end swing cylinder shaft; 7 is the flange; 8 is the proximal finger end swing cylinder; 9 is the proximal finger end swing cylinder shaft; 10 is the finger joint torsion bevel gear; 11 is the finger joint swing bevel gear; 12 is the finger joint torsion base; 13 is the finger joint swing bevel gear shaft; 14 is the lower finger joint; 15 is the upper finger joint; 16 is the adjustable pin shaft; 17 is the anti-slip pad. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0036] Example 1

[0037] In this embodiment, a hydraulic joint multi-degree-of-freedom manipulator is used. The manipulator consists of n manipulator units, where n is a positive integer. The number of manipulator claws can be determined before work based on the shape, size, weight, etc. of the clamped object and the working conditions.

[0038] In this embodiment, each manipulator unit is assembled in the sleeve 3 and fixedly connected to the inner bottom surface of the sleeve 3 via the base 4, and assembled to the end of the industrial robot through bolts and the like to serve as its actuator.

[0039] In this embodiment, a single manipulator unit includes a wrist joint 1 and a finger joint 2; the wrist joint 1 includes a distal finger end swing cylinder 5, a distal finger end swing cylinder shaft 6, a proximal finger end swing cylinder 8, a proximal finger end swing cylinder shaft 9, a finger joint torsion bevel gear 10, a finger joint swing bevel gear 11, a finger joint torsion base 12 and a finger joint swing bevel gear shaft 13; the finger joint includes a lower finger joint 14, an upper finger joint 15 and an adjustable pin shaft 16.

[0040] In this embodiment, both the distal finger end swing cylinder 5 and the proximal finger end swing cylinder 8 are hydraulic swing cylinders. The use of hydraulic swing cylinders has a larger torque range and is easier to maintain a constant angle after adjustment.

[0041] In this embodiment, the distal finger end swing cylinder 5 is fixed to the bottom of the wrist joint 1 sleeve 3 through the base 4, and its output shaft, i.e., the distal finger end swing cylinder shaft 6, passes through the flange 7 and the proximal finger end swing cylinder 8 and the proximal finger end swing cylinder shaft 9 to be fixed to the finger joint twisting base 12. Under the impetus of hydraulic pressure, it outputs a widely adjustable torque, stably and accurately drives the finger joint twisting base 12 to rotate, thereby playing a role in adjusting the swing angle of the entire finger joint 2.

[0042] In this embodiment, the proximal finger end swing cylinder 8 is fixed together with the distal finger end swing cylinder 5 through the flange 7, and its hollow output shaft, that is, the proximal finger end swing cylinder shaft 9 is fixed together with the finger joint torsion bevel gear 10, and outputs a wide range of adjustable torque under the impetus of hydraulic pressure, stably and accurately driving the finger joint 2 torsion bevel gear 10 to rotate; because the finger joint swing bevel gear 11 and the finger joint torsion bevel gear 10 are meshed with each other, the finger joint torsion bevel gear 10 and the finger joint torsion base 12 are separated from each other, and the finger joint The knuckle torsion base 12 remains stationary under the consolidation of the distal finger end swing cylinder shaft 6, so the knuckle swing bevel gear 11 rotates around a fixed axis driven by the knuckle torsion bevel gear; and because one end of the knuckle swing bevel gear shaft 13 is fixed to the knuckle swing bevel gear 11, and the other end passes through the knuckle torsion base 12 and is fixed to the lower knuckle 14 of the knuckle, the knuckle swing bevel gear 11 ultimately drives the entire knuckle 2 to swing, and the swing angle of each knuckle 2 can be adjusted separately to achieve the clamping and loosening of the clamped object.

[0043] In this embodiment, multiple grippers can cooperate with each other by adjusting the swing angles of their own finger joints 2, so as to more conveniently clamp parts of different shapes. Figure 6 Schematic diagram of a three-claw robot gripping a column. Figure 7 This is a schematic diagram of a three-claw manipulator holding a spherical object. These two shapes of objects are the most common. The present invention can easily achieve this by adjusting the swing angle of each claw, and can also make each claw swing to any angle. In addition, a hydraulic swing cylinder is used, which has a larger torque range and is easier to maintain a constant angle after adjustment.

[0044] In this embodiment, the rotation direction of the knuckle torsion bevel gear 10 is consistent with the torsion direction of the knuckle 2; the knuckle swing bevel gear 11 is fixedly connected to the knuckle swing bevel gear shaft 13, and its rotation direction is consistent with the swing direction of the knuckle 2; the knuckle torsion bevel gear 10 and the knuckle swing bevel gear 11 are meshed with each other to control the swing angle and speed of the knuckle 2. The near finger end swing cylinder shaft 9 is a hollow output shaft, and the inner diameter of the hollow shaft is larger than the outer diameter of the far finger end swing cylinder shaft 6.

[0045] In this embodiment, the lower knuckle 14 and the upper knuckle 15 of the finger joint 2 are hinged by an adjustable pin 16, and the lower knuckle 14 is fixedly connected to the knuckle swing bevel gear shaft 13. The adjustable pin 16 is used to adjust the angle between the lower knuckle 14 and the upper knuckle 15. The angle between the two knuckles can be adjusted and fixed according to the shape and size of the clamped object. The length, shape, material, etc. of the lower knuckle 14 and the upper knuckle 15 of the mechanical finger joint 2 can be customized.

[0046] In this embodiment, the upper knuckle 15 and the lower knuckle 14 are each provided with an anti-skid pad 17 on their clamping side to increase the friction coefficient. The number of manipulator units, the angle of the knuckle 2 and the material of the anti-skid pad 17 on the knuckle 2 are replaced and adjusted according to the material, size and shape of the clamped object.

[0047] In this embodiment, the output shaft of the distal finger end swing cylinder 5 drives the finger joint twisting base 12 to twist, thereby adjusting the clamping angle of each finger joint 2 to adapt to different parts shapes and sizes. During this process, the finger joint swing bevel gear 11 can only roll on the circumference of the finger joint twisting bevel gear 10 driven by the finger joint twisting base 12 because the finger joint twisting bevel gear 10 is fixed, thereby affecting the swinging angle, but the angle can be adjusted separately afterwards; the output shaft of the proximal finger end swing cylinder 8 drives the finger joint twisting bevel gear 10 to rotate, and the finger joint swing bevel gear 11 can only rotate around a fixed axis because the finger joint twisting base 12 is stationary, thereby driving the finger joint swing bevel gear shaft 13 and the finger joint 2 to swing, so as to adjust the clamping force of each finger joint 2.

[0048] In summary, the hydraulic joint multi-degree-of-freedom manipulator in this scheme has high flexibility, large torque range, compact and light structure, and many of its components have good independence, which can realize modular design.

[0049] Example 2

[0050] In this embodiment, a control method for a hydraulic joint multi-degree-of-freedom manipulator is applied. In this method, first, the distal finger end swing cylinder 5 is controlled to make the distal finger end swing cylinder shaft 6 drive the finger joint twisting base 12 to twist, and then adjust the twisting angle, that is, the clamping angle, of each finger joint 2 to adapt to different parts shapes and sizes; then the proximal finger end swing cylinder 8 is controlled to make the proximal finger end swing cylinder shaft 9 drive the finger joint twisting bevel gear 10 to rotate. At this time, the finger joint swing bevel gear 11 rotates around a fixed axis because the finger joint twisting base 12 is stationary, and then drives the finger joint swing bevel gear shaft 13 and the finger joint to swing, so as to adjust the swinging angle and speed of each finger joint 2, that is, to adjust the clamping force of each finger joint 2.

[0051] In this embodiment, the number of grippers can be determined according to the shape, size, weight, etc. of the clamped object and the working conditions before working, and can be connected by bolts at the bottom of the sleeve 33 of the wrist joint 1. The grippers can be 2, 3, 4, 6, etc. For example: 2 grippers are suitable for square clamped objects, 3 grippers are suitable for spherical clamped objects, 4 grippers are suitable for rod-shaped and stick-shaped clamped objects, etc., and 6 grippers are suitable for heavy clamped objects.

[0052] In this embodiment, the finger joints 2 of the manipulator can also be replaced according to the work object to be clamped. The length, shape, material, etc. of the lower finger joints 14 and the upper finger joints 15 can be customized. The angle between the lower finger joints 14 and the upper finger joints 15 can be adjusted arbitrarily through the adjustable pin shaft 16, and the anti-slip pad 17 can be replaced to better adapt to the shape, size, material, etc. of the clamped object.

[0053] In this embodiment, when the clamped object is large, the length of the upper and lower knuckles 14 can be increased, otherwise reduced; when the clamped object is fragile or valuable, the upper and lower knuckles 14 and anti-skid pads 17 are replaced with flexible materials; when the clamped object is very smooth, the anti-skid pads 17 with a higher friction coefficient are replaced.

[0054] In this embodiment, after adjusting the number of claws and the specifications of the finger joints 2 according to the needs, the entire manipulator is installed at the end of the mechanical arm, and first, the distal finger end swing cylinder 5 of each claw is driven to drive the distal finger end swing cylinder shaft 6 and the finger joint twisting base 12 to twist clockwise / counterclockwise, so that each claw is twisted to the required angle. During this period, the finger joint twisting bevel gear 10 is stationary, and the finger joint swing bevel gear 11 rolls on the circumference of the finger joint twisting bevel gear 10 due to the twisting of the finger joint twisting base 12, thereby causing the finger joint swing bevel gear shaft 13 and the lower finger joint 14 and upper finger joint 15 of the entire finger joint 2 to swing, so it is necessary to pay attention to the position of the finger joint 2. When it is in a more dangerous position, it is adjusted by driving the proximal finger end swing cylinder 8.

[0055] In this embodiment, after the torsion angle of each gripper is determined, the hydraulic pressure of the distal finger end swing cylinder 5 is used to maintain the torsion angle of the gripper constant, and then the proximal finger end swing cylinder 8 of each gripper is driven to drive the proximal finger end swing cylinder shaft 9 and the finger joint torsion bevel gear 10 to twist counterclockwise / clockwise. Because the knuckle swing bevel gear 11 and the knuckle torsion bevel gear 10 are meshed with each other, the knuckle torsion bevel gear 10 and the knuckle torsion base 12 are separated from each other, and the knuckle torsion base 12 remains stationary under the consolidation of the distal finger end swing cylinder shaft 6, the knuckle swing bevel gear 11 rotates around a fixed axis driven by the joint torsion bevel gear; and because one end of the knuckle swing bevel gear shaft 13 is fixed to the knuckle swing bevel gear 11, and the other end passes through the knuckle torsion base 12 and is fixed to the lower knuckle 14 of the knuckle, the knuckle swing bevel gear 11 eventually drives the entire knuckle 2 to swing outward / inward, and the swing angle and speed of each knuckle 2 can be adjusted separately to achieve clamping / loosening of the clamped object.

[0056] In summary, the control method of a hydraulic joint multi-degree-of-freedom manipulator in this scheme is simple to control and has high flexibility.

[0057] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A hydraulic joint multi-degree-of-freedom manipulator, characterized in that: The manipulator is composed of n manipulator units, where n is a positive integer. Each manipulator unit is assembled in a sleeve (3) and fixedly connected to the inner bottom surface of the sleeve (3) via a base (4). A single manipulator unit comprises a wrist joint (1) and a finger joint (2); the wrist joint (1) comprises a distal finger end swing cylinder (5), a distal finger end swing cylinder shaft (6), a proximal finger end swing cylinder (8), a proximal finger end swing cylinder shaft (9), a finger joint torsion bevel gear (10), a finger joint swing bevel gear (11), a finger joint torsion base (12) and a finger joint swing bevel gear shaft (13), providing driving and control capabilities; the finger joint comprises a lower finger joint (14), an upper finger joint (15) and an adjustable pin shaft (16), providing clamping capabilities.

2. A hydraulic joint multi-degree-of-freedom manipulator according to claim 1, characterized in that: The distal finger end swing cylinder (5) and the proximal finger end swing cylinder (8) are both hydraulic swing cylinders.

3. A hydraulic joint multi-degree-of-freedom manipulator according to claim 1, characterized in that: In the wrist joint (1), the distal finger end swing cylinder (5) is fixedly connected to the base (4), and its output shaft is the distal finger end swing cylinder shaft (6), which is fixedly connected to the finger joint twisting base (12) and outputs torque under the impetus of hydraulic pressure to adjust the twisting angle of the finger joint (2); The proximal finger end swing cylinder (8) is connected to the upper part of the distal finger end swing cylinder (5) via a flange (7), and its output shaft is the proximal finger end swing cylinder shaft (9), which is fixedly connected to the finger joint torsion bevel gear (10) and outputs torque under the impetus of hydraulic pressure to adjust the swing angle of the finger joint (2).

4. The hydraulic joint multi-degree-of-freedom manipulator according to claim 1, characterized in that: The rotation direction of the knuckle torsion bevel gear (10) is consistent with the torsion direction of the knuckle (2); the knuckle swing bevel gear (11) is fixedly connected to the knuckle swing bevel gear shaft (13), and its rotation direction is consistent with the swing direction of the knuckle (2).

5. The hydraulic joint multi-degree-of-freedom manipulator according to claim 1, characterized in that: The finger joint torsion bevel gear (10) and the finger joint swing bevel gear (11) are meshed with each other and are used to control the swing angle and speed of the finger joint (2).

6. The hydraulic joint multi-degree-of-freedom manipulator according to claim 1, characterized in that: The proximal finger end swing cylinder shaft (9) is a hollow output shaft, and the inner diameter of the hollow shaft is larger than the outer diameter of the distal finger end swing cylinder shaft (6).

7. The hydraulic joint multi-degree-of-freedom manipulator according to claim 1, characterized in that: The wrist joint (1) adopts a ball double-helix hydraulic swing joint.

8. The hydraulic joint multi-degree-of-freedom manipulator according to claim 1, characterized in that: The lower knuckle (14) and the upper knuckle (15) of the knuckle (2) are hingedly connected via an adjustable pin shaft (16), the lower knuckle (14) is fixedly connected to the knuckle swing bevel gear shaft (13), and the adjustable pin shaft (16) is used to adjust the angle between the lower knuckle (14) and the upper knuckle (15).

9. The hydraulic joint multi-degree-of-freedom manipulator according to claim 1, characterized in that: The upper knuckle (15) and the lower knuckle (14) are each provided with an anti-skid pad (17) on the clamping side thereof, so as to increase the friction coefficient.

10. A control method for a hydraulic joint multi-degree-of-freedom manipulator, characterized in that: The method is applied in a hydraulic joint multi-degree-of-freedom manipulator as described in any one of claims 1 to 9. In the method, the distal finger end swing cylinder (5) is first controlled so that the distal finger end swing cylinder shaft (6) drives the finger joint twisting base (12) to twist, thereby adjusting the twisting angle, i.e., the clamping angle, of each finger joint (2) to adapt to different parts shapes and sizes; then the proximal finger end swing cylinder (8) is controlled so that the proximal finger end swing cylinder shaft (9) drives the finger joint twisting bevel gear (10) to rotate. At this time, the finger joint swing bevel gear (11) rotates along a fixed axis because the finger joint twisting base (12) is stationary, thereby driving the finger joint swing bevel gear shaft (13) and the finger joint (2) to swing, thereby adjusting the swinging angle and speed of each finger joint (2), i.e., adjusting the clamping force of each finger joint (2).

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