A flexible adjusting robot arm flexible joint structure

Abstract

The utility model relates to flexible joint technical field, and disclose a kind of robot arm flexible joint structure of flexible adjustment, including end moving part and connecting rod moving part, both are connected by spherical movable roll and spherical movable groove gap cooperation, the adjusting column of connecting rod moving part right end is connected with magnetorheological elastomer ring, there is solenoid on ring, there is circumferential array's nickel-titanium alloy spring between end moving part and connecting rod moving part, close solenoid, magnetorheological elastomer ring stiffness is low, joint full flexibility, activate nickel-titanium alloy spring, joint can small amplitude rotation adjustment, combine tactile sensor feedback, can realize the light and soft action of dynamic following, when needing big support force, solenoid is energized, magnetorheological elastomer ring stiffness is promoted, constrain end moving part and connecting rod moving part, lock joint form, nickel-titanium alloy spring increases contraction amplitude, output high degree, applicable to deep massage etc. Operation, can accurately transmit massage degree, improve physiotherapy effect.

Description

Technical Field

[0001] This utility model relates to the field of flexible joint technology, specifically to a flexible joint structure for a flexibly adjustable robotic arm. Background Technology

[0002] Stiffness adjustment of magnetorheological elastomers (MREs) is achieved by utilizing their properties. MREs are composed of iron particles doped with a silicone matrix. They have low stiffness in the absence of a magnetic field. When a magnetic field is applied, the iron particles rearrange themselves within the silicone matrix, and the stiffness of the MRE changes with the strength of the magnetic field. By adjusting the current in the electromagnetic coil to control the magnetic field strength, the stiffness can be dynamically adjusted. This method is applicable to various mechanical structures that require variable stiffness. Flexible joints are mechanical components that differ from traditional rigid joints. With the help of variable stiffness materials and intelligent drives, they can achieve flexible movement and stiffness adjustment. For example, using magnetorheological elastomers and shape memory alloys, they can perform gentle, adaptive movements at low stiffness and provide stable support at high stiffness. They are widely used in fields such as robotic massage and rehabilitation medicine to improve the comfort and effectiveness of operation.

[0003] Traditional joint structures have significant shortcomings in terms of flexibility and stiffness adjustment. When performing gentle movements, traditional joints cannot flexibly adapt to the complex contours of the human body, are prone to causing discomfort due to rigid contact, and cannot accurately simulate human hand movements. They also cannot accurately control movements according to different pressure changes, resulting in a poor massage experience. When greater support and stability are required, traditional joints cannot quickly adjust stiffness, resulting in poor joint stability, easy dispersion of massage force, inability to effectively transmit force to human tissues, difficulty in penetrating deep into the muscle layer, low precision in stimulating acupoints and muscle groups, and poor therapeutic effects. To address these issues, we propose a flexible joint structure for a robotic arm with flexible adjustment. Summary of the Invention

[0004] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a flexible joint structure for a flexibly adjustable robotic arm, thus solving the aforementioned problems.

[0005] (II) Technical Solution To achieve the above-mentioned objectives, this utility model provides the following technical solution: a flexible joint structure for a flexibly adjustable robot arm, comprising an end effector and a connecting rod. A spherical movable roller is fixed to the right side of the end effector. A spherical movable groove is provided inside the connecting rod, and the spherical movable roller is disposed inside the spherical movable groove with a clearance fit. Multiple adjusting posts are fixed to the right end of the connecting rod, and magnetorheological elastomer rings are sleeved on the multiple adjusting posts. Electromagnetic coils are provided on the annulus of the magnetorheological elastomer rings. Multiple nickel-titanium alloy springs arranged in a circumferential array are provided between the end effector and the connecting rod. The end face of the end effector and the connecting rod is provided with an end effector connecting ring and a connecting rod connecting ring.

[0006] Preferably, the connecting rod movable component has a spherical movable groove inside, and a spherical movable roller is fixed to the left end of the end movable component. A connecting end is fixed to the left end of the spherical movable roller, and a flexible inner ring is formed inside the spherical movable roller and the connecting end.

[0007] Preferably, the right end face of the connecting rod is fixed with a plurality of adjusting columns arranged in a circular array, the magnetorheological elastomer rings are distributed in a circular shape, the magnetorheological elastomer rings are provided with a plurality of sleeve holes, the plurality of magnetorheological elastomer rings are sleeved on the adjusting columns through the sleeve holes, and a plurality of electromagnetic coils are provided on the circular magnetorheological elastomer rings.

[0008] Preferably, the end movable component has a plurality of circumferentially arrayed fixing holes, and a plurality of adjusting posts on the right end face of the connecting rod movable component are inserted into the fixing holes, wherein a plurality of magnetorheological elastomer rings are disposed between the left end of the end movable component and the right end face of the connecting rod movable component.

[0009] Preferably, the inner ring of the connecting rod movable part is fixed with six sets of connecting posts arranged in a circumferential array, and the inner ring of the end movable part is fixed with six sets of connecting posts arranged in a circumferential array. The connecting posts two correspond to the connecting posts one, and the two sides of the nickel-titanium alloy spring are respectively connected to the connecting posts one and the connecting posts two.

[0010] Preferably, the left end face of the connecting rod movable part is provided with a circular connecting rod connecting ring, and the right end face of the end movable part is provided with a circular end actuator connecting ring, wherein the end actuator connecting ring and the connecting rod connecting ring are provided with a plurality of circumferentially arrayed connecting holes.

[0011] Compared with the prior art, this utility model provides a flexible joint structure for a flexibly adjustable robotic arm, which has the following advantages: 1. This flexible joint structure with adjustable stiffness using a magnetorheological elastomer, when requiring gentle movements, shuts off the electromagnetic coil. The magnetorheological elastomer ring's magnetic field strength is zero, resulting in low stiffness and a fully flexible joint. The end effector and connecting rod are loosely connected, allowing for easy, minute rotations and adjustments. In massage scenarios, it flexibly adapts to complex human contours. For example, during facial massage, it gently conforms to areas such as around the eyes and nose, avoiding discomfort caused by rigid contact. It precisely simulates human hand movements by selectively activating circumferentially arrayed nickel-titanium alloy springs and adjusting the current and energizing combination in real time using tactile sensor feedback. This accurately simulates the "kneading" motion of a human hand. During the simulated kneading motion, the springs alternately contract according to a sine wave sequence, precisely controlling the degree of contraction in conjunction with different pressure changes, providing users with a natural and comfortable massage experience and significantly enhancing the massage experience.

[0012] 2. This flexible joint structure with adjustable magnetorheological elastomer stiffness provides stable rigid support. When the massage robot needs to perform deep massage or fix the body position, the system switches to rigid support mode. Current is supplied to the electromagnetic coil, and the stiffness of the magnetorheological elastomer ring rapidly increases, tightly constraining the end effector and connecting rod, locking the joint shape. During deep muscle massage, it ensures joint stability, allowing the massage force to be accurately transmitted to the human tissue, avoiding force dispersion due to joint wobbling, and improving the massage effect. With increased joint stiffness, the nickel-titanium alloy spring has a larger contraction amplitude, combined with high-intensity output. This high-intensity, stable massage method can penetrate deep into the human muscle layer, effectively relieving muscle fatigue and promoting blood circulation. Compared with traditional massage methods, it can more accurately stimulate acupoints and muscle groups, achieving better therapeutic effects and meeting users' needs for deep therapy. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the structure of this utility model; Figure 3 This is a cross-sectional view of the structure of this utility model; Figure 4 This is a schematic diagram showing the structural breakdown of this utility model; Figure 5 This is a schematic diagram of the connecting rod movable component of this utility model; Figure 6 This is a schematic diagram of the end-effector structure of this utility model; Figure 7 This is a schematic diagram of the connection structure between the magnetorheological elastomer ring and the electromagnetic coil of this utility model.

[0014] In the diagram: 1. End effector connecting ring; 2. End effector moving part; 3. Magnetorheological elastomer ring; 4. Electromagnetic coil; 5. Adjusting column; 6. Linkage moving part; 7. Nickel-titanium alloy spring; 8. Linkage connecting ring; 9. Connecting end; 10. Spherical moving groove; 11. Connecting column one; 12. Flexible inner ring; 13. Connecting column two; 14. Spherical moving roller; 15. Sleeve hole. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0016] Please see Figure 1-7 A flexible joint structure for a flexibly adjustable robotic arm includes an end effector 2 and a connecting rod 6. A spherical movable roller 14 is fixed to the right side of the end effector 2. A spherical movable groove 10 is opened inside the connecting rod 6. The spherical movable roller 14 is disposed inside the spherical movable groove 10 and is connected with clearance. Multiple adjusting posts 5 are fixed to the right end of the connecting rod 6. A magnetorheological elastomer ring 3 is sleeved on the multiple adjusting posts 5. An electromagnetic coil 4 is arranged on the ring of the magnetorheological elastomer ring 3. Multiple nickel-titanium alloy springs 7 arranged in a circumferential array are arranged between the end effector 2 and the connecting rod 6. An end effector connecting ring 1 and a connecting rod connecting ring 8 are provided on the end face of the end effector 2 and the connecting rod 6.

[0017] Furthermore, the connecting rod movable part 6 has a spherical movable groove 10 inside, and a spherical movable roller 14 is fixed to the left end of the end movable part 2. A connecting end 9 is fixed to the left end of the spherical movable roller 14. A flexible inner ring 12 is provided inside the spherical movable roller 14 and the connecting end 9, so as to realize the flexible movement and stiffness adjustment of the joint in different modes, and can accurately simulate the human hand movement.

[0018] Furthermore, multiple adjusting columns 5 arranged in a circular array are fixed on the right end face of the connecting rod movable part 6. The magnetorheological elastomer rings 3 are distributed in a circular shape, and multiple sleeve holes 15 are opened on the magnetorheological elastomer rings 3. The multiple magnetorheological elastomer rings 3 are sleeved on the adjusting columns 5 through the sleeve holes 15. Multiple electromagnetic coils 4 are arranged on the circular magnetorheological elastomer rings 3, which can achieve flexible bending of ±30° in a flexible state and accurately simulate human hand movements, and provide stable support in a rigid state to meet the different force operation requirements of massage robots.

[0019] Furthermore, the end movable part 2 is provided with a plurality of circumferentially arrayed fixing holes, and the plurality of adjusting posts 5 on the right end face of the connecting rod movable part 6 are inserted into the fixing holes. Among them, a plurality of magnetorheological elastomer rings 3 are arranged between the left end of the end movable part 2 and the right end face of the connecting rod movable part 6.

[0020] Furthermore, six sets of connecting posts 11 arranged in a circular array are fixed inside the ring of the connecting rod movable part 6, and six sets of connecting posts 23 arranged in a circular array are fixed inside the ring of the end movable part 2. The connecting posts 23 correspond to the connecting posts 11, and the two sides of the nickel-titanium alloy spring 7 are connected to the connecting posts 11 and the connecting posts 23 respectively. Through the connection of the nickel-titanium alloy spring 7, the joint can rotate flexibly by ±30°.

[0021] Furthermore, the left end face of the connecting rod movable part 6 is provided with a circular connecting rod connecting ring 8, and the right end face of the end movable part 2 is provided with a circular end effector connecting ring 1. The end effector connecting ring 1 and the connecting rod connecting ring 8 are provided with multiple circumferential array connecting holes. Through the multiple circumferential array connecting holes, they can be quickly and stably connected to other mechanical parts, so that the entire flexible joint structure can be efficiently integrated and applied in devices such as massage robots.

[0022] Structural Description: End effector connecting ring 1: The end effector connecting ring 1 is located on the right end face of the end movable part 2. It is circular in shape, and the connecting holes in the circumferential array on it are used to connect the end effector. It is the key interface for realizing the function. End component 2: End component 2 serves as one end of the joint movement. The right side is fixed with a spherical movable roller 14, which cooperates with the connecting rod movable component 6 to realize the joint movement. It is also provided with a fixing hole for insertion into the adjusting column 5. Magnetorheological elastomer ring 3: The magnetorheological elastomer ring 3 is sleeved on the adjusting column 5 and is in the shape of a ring. Its stiffness is changed by the electromagnetic coil 4 to adjust the overall rigidity of the joint and meet different operating requirements. Electromagnetic coil 4: Electromagnetic coil 4 is equidistantly distributed on the magnetorheological elastomer ring 3. By passing an electric current through it, a magnetic field is generated, which changes the stiffness of the magnetorheological elastomer ring 3, thereby realizing dynamic adjustment of joint stiffness. Adjustment column 5: Adjustment column 5 is fixed to the right end of the connecting rod movable part 6. Multiple columns are arranged in a circumferential array to support and fix the magnetorheological elastomer ring 3, and work together to realize the multiple functions of the joint. Linkage movable component 6: The link movable component 6 has a spherical movable groove 10 inside, an adjusting column 5 at the right end, a connecting column 11 inside the ring, and a link connecting ring 8 on the left end face. It is an important supporting structure of the joint. Nickel-titanium alloy spring 7: Nickel-titanium alloy spring 7 is distributed in a circular array between the end movable part 2 and the connecting rod movable part 6, connecting the first connecting post 11 and the second connecting post 13, driving the joint bending movement; Linkage connecting ring 8: The linkage connecting ring 8 is located on the left end face of the linkage moving part 6. It is circular in shape and has a circumferential array of connecting holes for connecting with other mechanical parts to realize joint integration applications. Connecting end 9: Connecting end 9 is fixed to the left end of the spherical movable roller 14 and has a flexible inner ring 12 inside, which plays a role in buffering and auxiliary connection during joint movement, and enhances joint flexibility; Spherical movable groove 10: The spherical movable groove 10 is opened inside the connecting rod movable part 6 and is in clearance fit with the spherical movable roller 14, providing flexible rotation space for the joint and ensuring the joint movement accuracy; Connecting column 11: There are six sets of connecting columns 11, which are fixed in a circular array inside the ring of the connecting rod movable part 6 and connected to one end of the nickel-titanium alloy spring 7 to transmit the spring force and realize the joint movement. Flexible inner ring 12: The flexible inner ring 12 is located inside the spherical movable roller 14 and the connecting end 9. It provides cushioning during joint movement, reduces component wear, and improves the smoothness of joint movement. Connecting post 2 13: There are six sets of connecting posts 2 13, which are fixed in a circular array inside the ring of the end movable part 2 and connected to the other end of the nickel-titanium alloy spring 7. They work together with connecting post 1 11 to realize joint movement. Spherical movable roller 14: The spherical movable roller 14 is fixed on both sides of the end movable part 2 and is in clearance fit with the spherical movable groove 10. It is a key component to realize the flexible rotation of the joint and ensure smooth movement. Sleeve hole 15: Sleeve holes 15 are formed on the magnetorheological elastomer ring 3, and multiple holes are evenly distributed. They are used to fit onto the adjusting column 5 to ensure the stable installation and functional realization of the magnetorheological elastomer ring 3.

[0023] Working Principle: When the system is in its initial state and requires gentle movement, the electromagnetic coil 4 is first turned off. At this time, the magnetic field strength of the magnetorheological elastomer ring 3 is zero, its stiffness remains low, and the entire joint is in a fully flexible state. In this state, the connection between the end effector 2 and the connecting rod 6 is relatively loose, and the joint can easily rotate and adjust to a small amplitude. Through the control circuit, the nickel-titanium alloy spring 7 is selectively activated. Since the nickel-titanium alloy spring 7 is distributed in a circumferential array between the end effector 2 and the connecting rod 6, the nickel-titanium alloy spring 7 on the left side of the connecting rod 6 contracts, pulling the end effector 2 to bend to the left around the mating point of the spherical movable roller 14 and the spherical movable groove 10, realizing the initial bending of the joint in the target direction. During the bending process, the tactile sensor collects the pressure data in contact with the human body in real time and feeds this data back to the control system. The control system adjusts the current magnitude and energizing combination of the nickel-titanium alloy spring 7 in real time according to the feedback signal, for example, in simulation When the massage robot performs hand kneading movements, it precisely controls the contraction of each spring according to different pressure changes, achieving dynamic following and providing users with a more natural and comfortable massage experience. When the massage robot needs to perform deep massage or fix the body position, which requires greater support and stability, the system switches to rigid support mode. The control system supplies current to the electromagnetic coil 4 to generate a magnetic field. Under the action of the magnetic field, the iron particles in the magnetorheological elastomer ring 3 rearrange in the silicone matrix, causing the stiffness of the magnetorheological elastomer ring 3 to increase rapidly. At this time, the magnetorheological elastomer ring 3 tightly binds the end moving part 2 and the connecting rod moving part 6 together, locking the joint shape. After being energized, the nickel-titanium alloy spring 7 further increases the contraction amplitude. Since the joint stiffness has been greatly improved, it can better resist the reaction force, thereby cooperating with the output of high force to achieve deep massage and other operations. When performing deep muscle massage, the stable joint structure can ensure that the massage force is accurately transmitted to the human tissue, achieving better physiotherapy results.

[0024] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A flexible joint structure for a flexibly adjustable robotic arm, comprising an end effector (2) and a linkage (6), characterized in that: A spherical movable roller (14) is fixed on the right side of the end movable part (2). A spherical movable groove (10) is opened inside the connecting rod movable part (6). The spherical movable roller (14) is set in the spherical movable groove (10) with a clearance fit. A plurality of adjusting columns (5) are fixed on the right end of the connecting rod movable part (6). A magnetorheological elastomer ring (3) is sleeved on the plurality of adjusting columns (5). An electromagnetic coil (4) is set on the ring of the magnetorheological elastomer ring (3). A plurality of nickel-titanium alloy springs (7) arranged in a circumferential array are set between the end movable part (2) and the connecting rod movable part (6). The end actuator connecting ring (1) and the connecting rod connecting ring (8) are provided on the end movable part (2) and the connecting rod movable part (6).

2. The flexible joint structure of a robot arm according to claim 1, characterized in that: The connecting rod movable part (6) has a spherical movable groove (10) in the shape of a ball inside. The left end of the end movable part (2) is fixed with a spherical movable roller (14) in the shape of a ball. The left end of the spherical movable roller (14) is fixed with a connecting end (9). The spherical movable roller (14) and the connecting end (9) have a flexible inner ring (12) inside.

3. The flexible joint structure of a flexibly adjustable robotic arm according to claim 2, characterized in that: The right end face of the connecting rod movable part (6) is fixed with a plurality of adjusting columns (5) arranged in a circular array. The magnetorheological elastomer ring (3) is distributed in a circular shape. The magnetorheological elastomer ring (3) is provided with a plurality of sleeve holes (15). The plurality of magnetorheological elastomer rings (3) are sleeved on the adjusting columns (5) through the sleeve holes (15). The magnetorheological elastomer ring (3) is provided with a plurality of electromagnetic coils (4) arranged at equal intervals.

4. The flexible joint structure of a flexibly adjustable robotic arm according to claim 1, characterized in that: The end movable part (2) is provided with a plurality of circumferential array of fixing holes, and the plurality of adjusting posts (5) on the right end face of the connecting rod movable part (6) are inserted into the fixing holes. The plurality of magnetorheological elastomer rings (3) are arranged between the left end of the end movable part (2) and the right end face of the connecting rod movable part (6).

5. The flexible joint structure of a flexibly adjustable robotic arm according to claim 4, characterized in that: The ring of the connecting rod movable part (6) has six sets of connecting posts (11) arranged in a circular array, and the ring of the end movable part (2) has six sets of connecting posts (13) arranged in a circular array. The connecting posts (13) correspond to the connecting posts (11), and the two sides of the nickel-titanium alloy spring (7) are connected to the connecting posts (11) and the connecting posts (13) respectively.

6. The flexible joint structure of a flexibly adjustable robotic arm according to claim 1, characterized in that: The left end face of the connecting rod movable part (6) is provided with a circular connecting rod connecting ring (8), and the right end face of the end movable part (2) is provided with a circular end actuator connecting ring (1). Multiple circular array connecting holes are provided on the end actuator connecting ring (1) and the connecting rod connecting ring (8).

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