Tendon-Driven Robotic Actuation with Tension Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current actuation systems for tendon-driven robotic mechanisms face challenges in achieving both strength and speed, with intrinsic actuation methods resulting in compact but limited finger motion and force production, while extrinsic actuation systems require complex cable transmission and lack efficient tension management.
Innovation Solution
The proposed actuation system incorporates a motor with an output shaft engaged to a ratchet mechanism, paired with flexor and extensor tendons, and includes a tension mechanism and strain gauge system for direct tension measurement and maintenance, along with a pulley system for parallel tendon orientation, enabling precise control and efficient tension application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If intrinsic actuation is used with motors in fingers and palm, then compact form is achieved, but finger motion and force production capabilities are limited
Solution Approach 1:
The patent introduces tendons as intermediary elements that transmit force from distal actuators to finger joints. The tendon mechanism allows compact actuator placement while maintaining force transmission capability through the tendon-cable system that spans across finger joints, resolving the contradiction between compact volume and force production.
2Power
If extrinsic actuation is used with cables from proximal actuators, then force production and speed are improved, but device complexity increases
Solution Approach 1:
The patent divides the actuation system into multiple independent distal actuators, each controlling specific finger joints. This segmentation eliminates the need for complex proximal cable transmission systems, reducing overall device complexity while maintaining force and speed capabilities through localized actuation units.
3Adaptability or versatility
If tendon-driven design is used, then flexible finger articulation is achieved, but friction and entanglement issues arise
Solution Approach 1:
The patent replaces traditional friction-prone mechanical tendon systems with a magnetic actuation system. Magnetic fields interact with ferromagnetic materials in the fingers to produce motion without physical contact, eliminating friction and entanglement losses while maintaining flexible articulation capability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enhances the articulation capabilities of robotic mechanisms by allowing for controlled and efficient tension distribution, improving both strength and speed, while minimizing friction and entanglement issues, thereby addressing the limitations of existing tendon-driven designs.
Implementation Method 1
each of the pair of tendons is in operative engagement with a strain gauge mechanism, which includes a cantilevered feature for enabling direct measurement of tension being applied to the pair of tendons through one or more strain gauges that measure the degree of deflection of the cantilevered feature
Implementation Method 2
a motor having an output shaft in operative engagement with a ratchet mechanism. The ratchet mechanism is engaged to a pair of tendons
Implementation Method 3
the pair of tendons is in operative engagement with a pulley system for redirecting the pair of tendons from a first orientation to a second orientation such that the pair of tendons is in parallel relation to each other
Data Source
AI summary
Systems and methods for an actuation system including a plurality of single actuation units for modular control of a tendon-driven robotic mechanism are disclosed.