Humanoid Robot Differential Linear Actuation Within the Human Envelope
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Solution Overview
Problem
Humanoid robots face a tradeoff between shape and performance due to limited space for actuators within the human envelope, with larger actuators providing better performance but requiring a larger volume.
Innovation Solution
The use of joint linear actuators configured for differential linear actuation in two degrees of freedom, including quasi-direct drive (QDD) linear actuators with low gear ratios, to adjust body joints, allowing for a more human-like shape and improved performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If larger actuators are used to improve robot performance, then the robot's performance is improved, but the robot cannot fit within the human envelope
Solution Approach 1:
The patent combines two linear actuators into a single integrated unit that provides both flexion-extension and abduction-adduction movements. This merging allows the robot to achieve the performance of two separate actuators while occupying the volume of one, resolving the contradiction between performance and size constraints within the human envelope.
Solution Approach 2:
The joint linear actuator is designed to perform multiple functions simultaneously - it can produce both flexion-extension and abduction-adduction movements at the shoulder joint. This multi-functionality allows the robot to maintain high performance across multiple degrees of freedom while using fewer, more compact actuator units that fit within the human envelope volume constraints.
2Adaptability or versatility
If more actuators are added to increase degrees of freedom, then the robot's mobility is improved, but the device complexity increases
Solution Approach 1:
The patent merges multiple actuator functions into a single joint linear actuator unit. Instead of using separate actuators for flexion-extension and abduction-adduction, the invention integrates both functions into one actuator, thereby reducing the total number of actuators and simplifying the overall system while maintaining full degrees of freedom mobility.
Solution Approach 2:
The joint linear actuator is designed as a universal component that can provide multiple degrees of freedom through differential linear actuation. This multi-functional design reduces device complexity by eliminating the need for multiple specialized actuators, while still achieving the desired mobility and adaptability across different joint movements.
Data Source
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AI summary
A robot includes a body assembly that includes a frame formed of at least one body joint assembly; and at least one pair of joint linear actuators that form the at least one body joint, the at least one pair of joint linear actuators configured to operate in combination to adjust the at least one body joint assembly in two degrees of freedom through differential linear actuation.