Compliant Torque Sensor Element With Magnetic Motion Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing torque sensors for robotic joints are limited in their ability to accurately measure torque due to reliance on measuring overlap between flexures, which can lead to inaccuracies and require complex overlap measurement methods.
Innovation Solution
A torque sensor element with a compliant arrangement that allows for relative rotation between outer and inner frames, featuring connecting structures with movable portions that translate rotational movement into measurable movements, such as rotation or translation, without needing to measure overlap, and optionally using magnetic elements to detect these movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If overlap measurement methods are used to measure torque, then torque measurement can be achieved, but measurement precision deteriorates due to inaccuracies and complexity
Solution Approach 1:
The patent replaces complex mechanical overlap measurement systems with magnetic field-based sensing. Magnets are attached to the inner frame and detected by sensors on the outer frame, substituting mechanical measurement with magnetic field detection to achieve more accurate and simpler torque measurement
Solution Approach 2:
The patent introduces magnets as an intermediary element between the inner and outer frames. These magnets create a magnetic field that serves as a mediator to transmit rotational position information without requiring direct mechanical contact or complex overlap measurements
2Measurement precision
If compliant arrangement allows relative rotation, then sensitivity to torque improves, but structural rigidity deteriorates
Solution Approach 1:
The torque sensor is segmented into distinct functional components: the compliant compliant arrangement for rotation, the magnets for field generation, and the sensors for detection. This segmentation allows each component to be optimized independently - the compliant structure for sensitivity and the sensor assembly for rigidity
Solution Approach 2:
The patent substitutes mechanical coupling between frames with magnetic field interaction. This allows the frames to remain mechanically independent and compliant while maintaining precise measurement capability through non-contact magnetic sensing
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
Provides a reliable and accurate method to measure torque applied to robotic joints by translating relative rotation into measurable movements, enhancing sensitivity and reducing measurement errors, while maintaining structural rigidity and preventing material damage.
Implementation Method 1
a first member and a second member, each extending between and connecting the outer frame to the inner frame, and each member being resilient and deformable to permit at least some relative rotation between the outer frame and the inner frame in response to a torque applied to the joint
Implementation Method 2
optionally using magnetic elements to detect these movements
Data Source
AI summary
A torque sensor element for measuring a torque applied to a joint is described. The torque sensor element includes: an outer frame and an inner frame respectively to connect to first and second sides of a joint; and a compliant arrangement connecting the outer frame to the inner frame. The compliant arrangement includes: first and second members, each extending between and connecting the outer and inner frames, and each being resilient and deformable to permit some relative rotation between the outer and inner frames in response to an applied torque. A connecting structure extends between the first and second members and includes a first portion intermediate the first and second members which is configured responsive to a deformation of the first and/or second member to move by an amount determined by a degree of relative rotation between the outer and inner frames caused by a torque applied to the joint.