Robot Torque Sensor Miniaturization via Integrated Encoder
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Solution Overview
Problem
Existing torque sensors for robots, which require high rigidity and resolution, often increase in size due to the need for two encoders (incremental and absolute) to oppose each other without obstacles, leading to displacement measurement issues, especially when objects hit the robot.
Innovation Solution
A torque sensor design featuring a first and second support portion that are relatively displaceable, incorporating an incremental encoder and a magnetoelectric transducer to measure relative displacement, allowing for miniaturization by using a magnetic-flux generating source and magnetoelectric transducer to compensate for displacement, reducing the size and improving measurement precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If two encoders (incremental and absolute) are used to measure displacement, then measurement precision and reliability are improved, but the sensor size increases due to placement restrictions
Solution Approach 1:
The patent combines the absolute encoder and incremental encoder into a single integrated encoder unit. The absolute scale and incremental scale are disposed on the same support portion, allowing both encoding functions to be performed in one compact structure rather than requiring separate encoder assemblies, thus reducing overall sensor size while maintaining dual-encoder measurement precision
Solution Approach 2:
The single support portion serves multiple functions by supporting both the absolute scale and incremental scale, as well as the magnetic-flux generating source and magnetoelectric transducer. This multi-functional design eliminates the need for separate support structures for each encoder type, contributing to sensor miniaturization
2Reliability
If two encoders are used to compensate for displacement loss, then reliability under sudden force is improved, but device complexity increases
Solution Approach 1:
By merging the absolute and incremental encoding functions into a single integrated encoder unit with scales on the same support portion, the patent reduces the complexity of having two separate encoder systems while maintaining the reliability benefits of dual-encoder displacement compensation
Solution Approach 2:
The integrated encoder unit performs self-compensation for displacement loss by combining absolute position data with incremental displacement data within the same measurement system, eliminating the need for complex external compensation mechanisms
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
The solution enables precise and stable torque measurement with high resolution, even under sudden force applications, such as when objects hit the robot, while minimizing the sensor's size by eliminating the need for separate absolute encoder placement.
Implementation Method 1
a magnetoelectric transducer supported by another of the first support portion and the second support portion
Data Source
AI summary
A sensor includes a first support portion, a second support portion, an incremental encoder, a magnetic-flux generating source, and a magnetoelectric transducer. The incremental encoder includes a scale supported by the first support portion and a head supported by the second support portion. The magnetic-flux generating source is supported by one of the first support portion and the second support portion. The magnetoelectric transducer is supported by another of the first support portion and the second support portion.