Tandem elastic damping driver for exoskeleton robot
By combining the series elastic damping driver structure of the damper and the elastic element, the problem of difficulty in achieving flexible driving in the prior art is solved, and the natural movement and stability of the robot's thighs and calf are realized, which can effectively absorb external impact force and improve the robot's thighs and calf. Movement ability in unstructured environments.
Patent Information
- Application Number
- CN202421143948.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-23
- Publication Date
- 2025-01-10
- Estimated Expiration
- 2034-05-23
AI Technical Summary
When the dynamic model of the existing series elastic driver is simplified, it is difficult to achieve flexible driving like human skeletal muscles, and cannot effectively absorb external impact forces, resulting in the robot's movements being not natural and stable enough.
Design a series elastic damping driver, which combines the damper and elastic components, uses a servo motor, screw nut, ball screw, spring and hydraulic buffer to form a new driver structure that can be impacted by external forces on the thighs and calf. At the same time, absorb impact force, weaken vibration, and achieve mechanical flexibility and stability of joints.
It realizes the naturalness and stability of the robot's thighs and calf movements, can effectively absorb external impact forces, reduce vibrations, and improve the robot's movement ability in an unstructured environment.
Smart Images
Figure CN222328190U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of drivers, in particular to a series elastic damping driver for an exoskeleton robot. Background Art
[0002] The concept of rehabilitation robots first appeared in the 20th century, but the limited technological level at that time restricted the application of robots in the field of rehabilitation. In recent years, with the continuous advancement of mechanical engineering control technology and sensor technology, rehabilitation robots have made significant progress, covering various medical fields, including neurological rehabilitation, sports rehabilitation and musculoskeletal rehabilitation. These robots can help patients walk and exercise, assist patients with joint activities, muscle exercises and balance training, which is especially important for patients with lower limb dysfunction and amputees, helping to accelerate the rehabilitation process, provide better rehabilitation experience and effects, and improve the quality of life of patients.
[0003] The key factor in the performance of lower limb exoskeleton rehabilitation robots lies in their movement ability. How the robot can show the naturalness, smoothness and adaptability of human walking during movement is very important for the practicality of the robot and human-machine interaction. There are many ways to achieve the flexibility of robot walking, such as designing a suitable gait generation algorithm, adjusting the gait parameters during the control algorithm to adapt to the changing environment and tasks, or equipping the robot with various sensors, such as inertial measurement units (IMUs), force sensors, and visual sensors, to obtain real-time environmental and robot status information. These feedbacks can be used to adjust the gait and posture to ensure the smooth movement of the robot. In addition, the use of flexible materials and structures by robots can reduce the impact when they collide and achieve more flexible movement.
[0004] Serial elastic actuator (SEA) is a drive system commonly used in robots, exoskeleton devices and other mechanical systems. Its main principle is to use elastic elements (such as springs, ropes, gas bags, etc.) to store and release energy, thereby achieving the drive and movement of the mechanical system. The characteristic of this actuator is that it can store and release energy, avoiding the impact and vibration that may be generated by traditional rigid actuators. Serial elastic actuators can enhance the movement ability of robots, improve the comfort and naturalness of exoskeleton devices, and make movement smoother and more efficient.
[0005] MIT Leg Laboratory proposed the concept and principle design of the series elastic actuator (SEA), and applied it to bipedal robots to achieve torque control. Marco Hutter and others from the Swiss Federal Institute of Technology developed a high-performance quadruped robot StarlETH, which uses a linear SEA as the driver of each joint. The joint SEA not only improves the accuracy of the torque control loop, but also ensures the energy efficiency of the robot, allowing StarlETH to have a high mobility in an unstructured environment. Venema uses a wire-pulling method to design the joint SEA, converting the force of the linear elastic element into the rotational torque of the joint, simplifying the motor into an ideal speed source model, and verifying the output force characteristics of the SEA.
[0006] Compared with rigid actuators, SEA has advantages such as structural impact resistance, low mechanical output impedance, and strong environmental adaptability. However, when simplifying the dynamic model of elastic elements, SEA is simplified to a pure stiffness link or damping link, and the dynamic model is imperfect. It is difficult to achieve flexible drive like human skeletal muscle by relying solely on elastic elements. Therefore, it is necessary to design a driver for exoskeleton robots that solves the above problems. Utility Model Content
[0007] The purpose of the utility model is to provide a series elastic damping driver for an exoskeleton robot, which can not only drive the thigh and calf of the robot to rotate, but also absorb the impact force of external load fluctuations when the thigh and calf are impacted by the outside world, weaken the vibration, and achieve mechanical flexibility and stability of the joints.
[0008] To achieve the above-mentioned purpose, the utility model provides a series elastic damping driver for an exoskeleton robot, including a servo motor, a fixed plate 1 is arranged at one end of the servo motor, the output end of the servo motor passes through the fixed plate 1 and is rotatably connected to an outer cylinder, the other end of the outer cylinder is fixedly connected to a lead screw nut, guide shafts are arranged at the four corners of the fixed plate 1, a partition plate is sleeved at the middle of the outer side of the guide shaft, a fixed plate 2 is arranged at the other end of the guide shaft, and dampers are arranged between the fixed plate 1 and the fixed plate 2 and the partition plate.
[0009] Preferably, a spring 1 is sleeved on the outer surface of the outer cylinder, and the number of the spring 1 is two.
[0010] Preferably, two ends of the outer cylinder are respectively sleeved with a bearing 1 and a bearing 2.
[0011] Preferably, a ball screw is threadedly connected to the middle of the screw nut, and a stop nut is sleeved on one end of the ball screw in the outer tube.
[0012] Preferably, the other end of the ball screw passes through the second fixing plate and is connected to a joint crank.
[0013] Preferably, a second spring is sleeved on the ball screw, and the second spring is arranged between the stop nut and the screw nut.
[0014] Preferably, the stop nut includes a stop ring, a nut body and a stop gasket, the stop ring, the nut body and the stop gasket are all fixedly mounted on the outer surface of the ball screw, the stop ring and the nut body are adjacent to each other, the stop gasket is between the nut body and the ball screw, and one side of the stop gasket is adjacent to the stop ring.
[0015] Preferably, each of the guide shafts is sleeved with a mold spring, and the number of the mold springs is eight.
[0016] Preferably, two brackets are symmetrically arranged on the outer side of the partition plate.
[0017] Preferably, the damper includes a hydraulic buffer and a damping rod, one end of the hydraulic buffer is fixedly connected to the partition plate, the other end of the hydraulic buffer is connected to the damping rod, and the other end of the damping rod is abutted against the fixed plate one or the fixed plate two.
[0018] Therefore, the utility model adopts the above structure, combines the damper with the elastic element, and forms a new type of actuator, namely, a series elastic damper actuator (SEDA), which can absorb the impact force of external load fluctuations and weaken vibration when the thigh and calf are impacted by the outside world, thereby achieving mechanical flexibility and stability of the joint.
[0019] The technical solution of the utility model is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 This is a schematic structural diagram of an embodiment of a series elastic damping driver for an exoskeleton robot according to the utility model;
[0021] Figure 2 It is a side view of an embodiment of a series elastic damping driver for an exoskeleton robot of the utility model;
[0022] Figure 3 This is a structural diagram of the interior of an outer cylinder of an embodiment of a series elastic damping driver for an exoskeleton robot of the utility model;
[0023] Figure 4It is a cross-sectional view of a locking nut and a ball screw of an embodiment of a series elastic damping driver for an exoskeleton robot of the utility model;
[0024] Figure 5 This is a structural diagram of the utility model applied to an exoskeleton robot;
[0025] Reference numerals
[0026] 1. Servo motor; 2. Fixing plate 1; 3. Outer cylinder; 4. Screw nut; 5. Guide shaft; 6. Partition plate; 7. Fixing plate 2; 8. Damper; 81. Hydraulic buffer; 82. Damping rod; 9. Spring 1; 10. Ball screw; 11. Check nut; 111. Check ring; 112. Nut body; 113. Check washer; 12. Joint crank; 13. Spring 2; 14. Mold spring; 15. Bracket; 16. Bearing 1; 17. Bearing 2. DETAILED DESCRIPTION
[0027] The technical solution of the utility model is further described below through the accompanying drawings and embodiments.
[0028] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the usual meanings understood by persons with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" and the like mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" and the like are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.
[0029] Example
[0030] like Figure 1-5 As shown, the utility model provides a series elastic damping driver for an exoskeleton robot, including a servo motor 1, one end of the servo motor 1 is provided with a fixing plate 2 by screws, the output end of the servo motor 1 passes through the fixing plate 2 and is rotatably connected to an outer cylinder 3, the outer surface of the outer cylinder 3 is sleeved with a spring 9, and the number of springs 9 is two. The two ends of the outer cylinder 3 are respectively sleeved with a bearing 16 and a bearing 2 17.
[0031] The other end of the outer cylinder 3 is fixedly connected with a screw nut 4, and guide shafts 5 are arranged at the four corners of the fixed plate 2, and the four guide shafts 5 are symmetrically arranged. The guide shafts 5 are sleeved with mold springs 14, and the number of mold springs 14 is eight. The mold springs 14 are symmetrically distributed to ensure the stable operation of the driver. A partition plate 6 is sleeved in the middle of the outer side of the guide shaft 5, and the middle of the entire driver is separated by the partition plate 6, which realizes the flexibility of the driver in both positive and negative directions. Two brackets 15 are symmetrically arranged on the outer side of the partition plate 6, and the brackets 15 can be connected to the partition plate 6 by screws. The entire driver can be installed on the exoskeleton robot through the brackets 15.
[0032] A fixing plate 2 7 is provided at the other end of the guide shaft 5, and a damper 8 is provided between the fixing plate 1 2 and the fixing plate 2 7 and the partition plate 6. The partition plate 6 separates the spring 1 9 and the mold spring 14. The damper 8 includes a hydraulic buffer 81 and a damping rod 82, one end of the hydraulic buffer 81 is fixedly connected to the partition plate 6, the other end of the hydraulic buffer 81 is connected to the damping rod 82, and the other end of the damping rod 82 abuts against the fixing plate 1 2 or the fixing plate 2 7. The damper 8 can increase the damping and can quickly attenuate the vibration caused by the impact.
[0033] The middle thread of the screw nut 4 is connected with a ball screw 10. When the screw nut 4 rotates, the ball screw 10 is driven to move inside the outer tube 3. One end of the ball screw 10 in the outer tube 3 is sleeved with a stop nut 11, and the other end of the ball screw 10 passes through the fixing plate 2 7 and is connected with a joint crank 12. The ball screw 10 is rotatably connected with the joint crank 12. The ball screw 10 is sleeved with a spring 2 13, which is arranged between the stop nut 11 and the screw nut 4. The spring 2 13 can eliminate the transmission clearance of the ball screw.
[0034] The stop nut 11 includes a stop ring 111, a nut body 112 and a stop washer 113. The stop ring 111, the nut body 112 and the stop washer 113 are all fixedly sleeved on the outer surface of the ball screw 10. The stop ring 111 and the nut body 112 are arranged adjacent to each other. The stop washer 113 is arranged between the nut body 112 and the ball screw 10, and one side of the stop washer 113 is arranged adjacent to the stop ring 111. The stop nut 11 can limit the ball screw 10 to prevent the ball screw 10 from coming out when moving in the outer cylinder 3.
[0035] Working principle: The servo motor 1 drives the outer cylinder 3 to rotate according to the control signal, the outer cylinder 3 drives the screw nut 4 to rotate, the screw nut 4 drives the ball screw 10 to move in the outer cylinder 3, the ball screw 10 drives the joint crank 12 to rotate, and the joint crank 12 then drives the thigh or calf to rotate. When the thigh and calf are impacted by the outside world, the force is transmitted to the damper 8 and the spring, so the spring and damper 8 can absorb the impact of external load fluctuations and weaken the vibration, thereby achieving a stable state and realizing the mechanical flexibility and stability of the joint.
[0036] Therefore, the utility model adopts a series elastic damping driver for an exoskeleton robot with the above structure, which can not only drive the robot's thigh and calf to rotate, but also absorb the impact force of external load fluctuations when the thigh and calf are subjected to external impact, weaken vibration, and achieve mechanical flexibility and stability of the joints.
[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in this field should understand that they can still modify or replace the technical solution of the utility model with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the utility model.
Claims
1. A series elastic damping actuator for an exoskeleton robot, characterized in that: It includes a servo motor, a fixing plate 1 is arranged at one end of the servo motor, the output end of the servo motor passes through the fixing plate 1 and is rotatably connected to an outer cylinder, the other end of the outer cylinder is fixedly connected to a lead screw nut, guide shafts are arranged at the four corners of the fixing plate 1, a partition plate is sleeved at the middle of the outer side of the guide shaft, a fixing plate 2 is arranged at the other end of the guide shaft, and dampers are arranged between the fixing plate 1 and the fixing plate 2 and the partition plate.
2. A series elastic damping actuator for an exoskeleton robot according to claim 1, characterized in that: The outer surface of the outer cylinder is sleeved with a spring 1, and the number of the spring 1 is two.
3. A series elastic damping actuator for an exoskeleton robot according to claim 1, characterized in that: The two ends of the outer cylinder are respectively sleeved with a bearing 1 and a bearing 2.
4. A series elastic damping actuator for an exoskeleton robot according to claim 1, characterized in that: The middle thread of the screw nut is connected with a ball screw, and one end of the ball screw in the outer tube is sleeved with a stop nut.
5. A series elastic damping actuator for an exoskeleton robot according to claim 4, characterized in that: The other end of the ball screw passes through the second fixing plate and is connected with a joint crank.
6. A series elastic damping actuator for an exoskeleton robot according to claim 4, characterized in that: The ball screw is sleeved with a second spring, and the second spring is arranged between the stop nut and the screw nut.
7. A series elastic damping actuator for an exoskeleton robot according to claim 4, characterized in that: The stop nut includes a stop ring, a nut body and a stop gasket. The stop ring, the nut body and the stop gasket are all fixedly mounted on the outer surface of the ball screw. The stop ring and the nut body are adjacent to each other. The stop gasket is disposed between the nut body and the ball screw, and one side of the stop gasket is adjacent to the stop ring.
8. A series elastic damping actuator for an exoskeleton robot according to claim 1, characterized in that: The guide shafts are all sleeved with mold springs, and the number of the mold springs is eight.
9. A series elastic damping actuator for an exoskeleton robot according to claim 1, characterized in that: Two brackets are symmetrically arranged on the outer side of the partition plate.
10. A series elastic damping actuator for an exoskeleton robot according to claim 1, characterized in that: The damper includes a hydraulic buffer and a damping rod, one end of the hydraulic buffer is fixedly connected to the partition plate, the other end of the hydraulic buffer is connected to the damping rod, and the other end of the damping rod is abutted against the fixed plate one or the fixed plate two.