Robot Joint Torque Path Layout for Accurate Bearing-Isolated Sensing
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Solution Overview
Problem
Conventional joint mechanisms with output links supported via multiple bearings face challenges in accurately detecting torque, leading to inadequate torque control accuracy and sensitivity, which hinders precision assembly work in robots.
Innovation Solution
The joint mechanism is designed with both bearing mechanisms positioned on the driving-portion-side torque transmission path, avoiding the output-link-side path to prevent reaction force moments from affecting the torque sensor, ensuring accurate torque detection and control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the output link is supported via multiple bearings to ensure mechanical robustness, then the mechanical stability is improved, but the torque detection accuracy deteriorates due to reaction force moments affecting the torque sensor
Solution Approach 1:
The patent segments the torque transmission path from the bearing support system by introducing a dedicated torque transmission mechanism (flexible coupling or torque transmission member) that physically separates the bearing reaction forces from the torque sensor measurement path, allowing independent optimization of both mechanical stability and measurement accuracy
Solution Approach 2:
The patent introduces an intermediary component (flexible coupling or torque transmission member) between the output link and torque sensor that transmits torque while isolating the sensor from bearing reaction forces, acting as a mediator that protects the measurement system from mechanical disturbances
2Device complexity
If the torque sensor is placed in the output-link-side torque transmission path, then the torque measurement is simplified, but the control sensitivity deteriorates due to interference from bearing reaction forces
Solution Approach 1:
The flexible coupling acts as an intermediary that transmits torque from the output link to the torque sensor while filtering out high-frequency vibration and reaction force interference, enabling accurate torque measurement without direct coupling that would transmit mechanical noise
Solution Approach 2:
The patent extracts the torque transmission function from the bearing support system by creating a separate, dedicated torque transmission path that is independent of the bearing reaction forces, allowing the torque sensor to measure only the relevant torque components
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 configuration allows for high-accuracy torque measurement and control, enhancing the responsivity of torque control in robots and enabling precise assembly work without complex control methods or pre-determination of reaction forces.
Implementation Method 1
The torque sensor includes an elastic member that deforms in accordance with the torque applied to the elastic member, and measures the output torque by detecting the amount of deformation or distortion of the elastic member
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A driving apparatus (200) is configured to displace a second link (1200) with respect to a first link (1100). The driving apparatus (200) includes a driving portion (202) including an output portion (202R) configured to output a driving force that displaces the second link (1200), a sensor (203) configured to obtain information on force, a connection member (205) configured to connect the output portion (202R) and the sensor (203), a first bearing (211), and a second bearing (212). The sensor (203) is connected between the second link (1200) and the connection member (205). The first bearing (211) and the second bearing (212) are connected to the connection member (205) for displacing the second link (1200) with respect to the first link (1100).