Multi-degree-of-freedom adaptive health assisting mechanical arm system and control method thereof

Abstract

The invention provides a low-cost customizable health assisting mechanical arm system which is provided with an extensible 3-5-degree-of-freedom joint module, and each joint adopts a unified electrical and mechanical interface; the replaceable end effector group comprises a two-finger clamping jaw, a three-finger self-adaptive hand and a four-finger flexible hand; and a self-adaptive control algorithm based on the current degree of freedom and the tail end form. Through degree-of-freedom modularization and end effector library design, full-scene coverage from basic article delivery to complex nursing operation is realized. The system can be flexibly configured according to user budget and requirements, and is suitable for daily life care of special groups such as old people, patients, disabled people and the like. The auxiliary care robot is mainly applied to the bedside of a residential family or a hotel apartment and the bedside of a nursing home and a sickroom to be used as the auxiliary care robot, can also be installed on a dining table, a sofa, a bathroom, a toilet and other occasions needing auxiliary care of people, and can be movably installed on an automobile and an outdoor camping facility after being disassembled.

Description

Technical Field

[0001] The present invention relates to the technical field of service robots, and in particular to a low-cost robotic arm system that supports 3-5 degrees of freedom joint configuration and has replaceable end gripping morphology, which is suitable for home health care scenarios. Background Art

[0002] In the prior art, health-assisting robotic arms often use fixed degrees of freedom (such as 6 degrees of freedom) and complex bionic hand designs. The advantages are beautiful appearance and high precision when the robotic arm is operated. For example, 202510271664X "A detachable multimodal AI health-assisting robotic arm system for bedside use" has 6 degrees of freedom in the robotic arm body, and a five-finger bionic hand (force control accuracy 0.1N) with up to 12 motion joints (carbon fiber material) is integrated at the end, but such a design leads to high costs and relatively difficult maintenance. If the degrees of freedom are reduced and the gripping form is simplified, the cost can be further reduced. The degrees of freedom are reduced: the number of robotic arm joints is reduced to 3-5, sacrificing flexibility to reduce costs; the gripping form is simplified: the five-finger hand is replaced by a two-finger gripper or a three-finger gripper to reduce the difficulty of manufacturing. The present invention can be regarded as a simplified version of 202510271664X "A detachable multimodal AI health-assisting robotic arm system for bedside use".

[0003] The present invention covers the above-mentioned variations through modular freedom combination and end effector quick-change design to form a simpler and much more affordable robotic arm system. Summary of the invention

[0004] The technical solution of the present invention includes a robot arm core architecture, a low-cost implementation path, and control algorithm adaptation.

[0005] The core architecture of the robotic arm is optimized and designed with scalable degrees of freedom: it supports 3-5 degrees of freedom joint configuration, and the joint module adopts a unified interface (compatible with Yushu Technology U series motors). Users can increase or decrease the number of joints as needed; the end effector library provides three replaceable forms: two-finger gripper (basic grasping), three-finger adaptive hand (wrapped grasping), and four-finger flexible hand (fine operation) ( Figure 1 ).

[0006] Low-cost implementation path: sensor simplification - the basic version only retains a monocular camera + ultrasonic sensor (instead of millimeter-wave radar); material downgrade - engineering plastics are used instead of carbon fiber in non-load-bearing parts.

[0007] Control algorithm adaptation: Adaptive degree of freedom planning - dynamically optimize the motion path based on the current number of joints (e.g. only perform in-plane actions when there are 3 degrees of freedom); Grip form recognition - automatically switch control parameters through the terminal ID chip (e.g. the force threshold of the two-finger gripper is set to 1-5N) ( Figure 2 ).

[0008] The innovation of this invention is reflected in three aspects: joint modularity, gripping form compatibility, and cost grading strategy. Joint modularity: 3-5 degrees of freedom rapid assembly is achieved through standardized interfaces, and the cost of single joint replacement is reduced by 60%; gripping form compatibility: the same robotic arm can switch between grippers / multi-fingered hands, covering the full scene requirements from object delivery to limb support; cost grading strategy: the price of the basic version (3 degrees of freedom + two-finger gripper) is half that of the 6 degrees of freedom + bionic hand version, and the price of the high-end version (5 degrees of freedom + four-finger hand) is about one-third lower than that of the 6 degrees of freedom + bionic hand version. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 : Schematic diagram of the structure of a multi-degree-of-freedom adaptable health-assisting robotic arm. In the figure: 1. Quick-release base for clip / magnetic / bolt installation; 2. Robotic arm body; 3. Voice player; 4. Telescopic and adjustable angle projection module; 5. Ring microphone matrix; 6. Binocular camera (can be changed to monocular camera); 7. Millimeter-wave radar (environmental modeling); 8. Infrared body temperature sensor; 9. Robotic arm degrees of freedom (3); 10. Mechanical gripper; 11. Robotic arm service position (bed).

[0010] Figure 2 : Adaptive planning graph with degrees of freedom.

[0011] Figure 3 : Schematic diagram of the combination of degrees of freedom and end effector.

[0012] Figure 4 : Two-finger gripper control flow chart. DETAILED DESCRIPTION

[0013] Example 1: 3 degrees of freedom + two-finger gripper (basic version) ( Figure 3 Scenario: delivering items next to a wheelchair. 1) The robotic arm is fixed to the wheelchair armrest, with the 3-DOF joint unfolded; 2) The two-finger gripper grabs the water cup (force limit 3N) and delivers it to the user's mouth; 3) The monocular camera identifies the user's head position to avoid collision.

[0014] Example 2: 3 degrees of freedom + two-finger gripper (basic version) ( Figure 3 ) Scenario: Picking up a medicine bottle. 1) Ultrasonic positioning of the bottle; 2) Adaptive adjustment of the distance between two fingers; 3) Force feedback closed-loop control; 4) Placement in the user's hand.

[0015] Example 3: 4-DOF + 3-finger adaptive hand (standard version). Scenario: Assisted eating at the table. 1) The robotic arm is installed on the edge of the table, and the 4-DOF joints achieve three-dimensional space movement; 2) The three-finger hand wraps around the spoon, and AI controls the scooping of food and maintains balance; 3) The ultrasonic sensor detects the opening and closing of the user's mouth and adjusts the feeding rhythm.

[0016] Example 4: 5-DOF + 4-finger flexible hand (high-end version). Scenario: Adjusting the bed cover. 1) The 5-DOF robotic arm extends from the bedside bracket; 2) The 4-finger hand pinches the corner of the quilt and unfolds it to cover the user's body; 3) The infrared sensor monitors the flatness of the quilt and adjusts it to the optimal state in a cycle.

Claims

1. A multi-degree-of-freedom adaptable health-assisting robotic arm system and a control method thereof, characterized in that include: Expandable 3-5 DOF joint modules, each joint adopts a unified electrical and mechanical interface; Replaceable end effector group, including two-finger gripper, three-finger adaptive hand, four-finger flexible hand; adaptive control algorithm based on the current number of degrees of freedom and end shape.

2. The system according to claim 1, characterized in that: The gripping surface of the two-finger gripper is covered with a silicone anti-slip layer and has a built-in pressure sensor (detection range 0.5-10N).

3. The system according to claim 1, characterized in that: The knuckles of the three-finger adaptive hand are provided with passive flexible joints, which can bend adaptively according to the shape of an object.

4. The system according to claim 1, characterized in that: The four-finger flexible hand integrates micro linear motors to support precise control of independent knuckles (displacement accuracy ±0.1 mm).

5. The system according to claim 1, characterized in that: The adaptive control algorithm comprises the following steps: reading the current number of joints and the end effector ID; loading the corresponding kinematic model from a pre-stored database; and adjusting the motion trajectory in real time according to the sensor input.

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