Wire-Driven Robot Merging Joints to Reduce Weight
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Solution Overview
Problem
Wearable robots with multiple joints require a driving device for each joint, increasing the robot's weight and leading to wearer fatigue and reduced working efficiency due to the increased load.
Innovation Solution
A wire-driven robot system where a single driving device winds or unwinds wires connected to multiple joints, reducing the number of driving units and distributing the weight, with tension detection and control to maintain optimal tension.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a driving device is provided for each joint, then each joint can be driven independently, but the total weight of the robot increases
Solution Approach 1:
Multiple driving devices that were previously distributed at each joint are merged into a single driving device located at the upper arm. This driving device uses a wire transmission mechanism to control multiple joints (shoulder, elbow, wrist) simultaneously, reducing the total number of driving devices from three to one, thereby significantly reducing the weight of the wearable robot.
Solution Approach 2:
A wire is introduced as an intermediary transmission medium between the single driving device and the multiple joints. The wire transmits the driving force from the upper arm to the hand and fingers, enabling remote actuation of joints without placing heavy motors at each joint location.
2Ease of operation
If the number of driving devices is increased, then each joint can be controlled precisely, but the burden on the wearer increases
Solution Approach 1:
The control functions for multiple joints are merged into a single driving device with coordinated control capability. The driving device can independently control the wire tension to actuate different joints (hand closing, wrist rotation, elbow bending, shoulder movement) while maintaining precise control through feedback mechanisms.
Solution Approach 2:
A tension detecting unit is incorporated to provide feedback on the wire tension status. This feedback enables the driving device to precisely control the wire tension, ensuring accurate joint actuation while adapting to the wearer's movements and reducing unnecessary burden.
3Adaptability or versatility
If multiple driving devices are used, then each joint can be actuated independently, but the cost increases
Solution Approach 1:
Instead of manufacturing and assembling three separate driving devices, the invention merges them into a single driving device with multi-joint control capability. This reduces manufacturing complexity, assembly requirements, and overall cost while maintaining the ability to actuate multiple joints independently through coordinated control.
Solution Approach 2:
The single driving device is designed with multi-functionality to perform the roles of multiple driving devices. It can independently control different joints based on control signals, making it a universal actuator that replaces several specialized devices, thereby reducing cost and simplifying the system.
Data Source
AI summary
A wire-driven robot includes pairs of arm parts including shoulder joints, elbow joints, and wrist joints to move with a motion of a wearer; a shoulder wire connected with the pair of shoulder joints; a shoulder driving unit applying a rotational force to the shoulder joints by winding or unwinding the shoulder wire in link with the motion of the wearer; an elbow wire connected with the pair of elbow joints; an elbow driving unit applying a rotational force to the elbow joints by winding or unwinding the elbow wire in link with the motion of the wearer; a wrist wire connected to the pair of wrist joints; and a wrist driving unit applying a rotational force to the wrist joints by winding or unwinding the wrist wire in link with the motion of the wearer.