Wave Reducer Angle Sensing Corrected for Cam Thrust Ripple
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Solution Overview
Problem
The amplitude of the output values of the bridge circuits in an angle sensor of a wave reducer changes due to thrust forces applied to the cam, leading to errors in the detection of the rotation angle.
Innovation Solution
A wave reducer with a sensor system that includes torque, angle, and thrust sensors, utilizing multiple strain gauges and bridge circuits to detect and correct for changes in output values caused by thrust forces, ensuring accurate detection of rotation angle and torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If strain gauges are used to detect rotation angle in the angle sensor, then the angle sensor can detect rotation angle based on bridge circuit output values, but the amplitude of the output values changes due to thrust force applied to the cam, causing detection errors
Solution Approach 1:
The patent introduces a thrust sensor as an intermediary device to detect the thrust force applied to the cam. This thrust sensor measures the actual thrust force, which is then used to correct the angle sensor output values. By adding this intermediary measurement system, the patent compensates for the amplitude changes in the bridge circuit output values caused by thrust force, thereby maintaining reliable and stable angle detection despite the presence of thrust variations.
2Ease of operation
If multiple strain gauges are arranged in bridge circuits to detect rotation angle, then angle detection is enabled, but the bridge circuit output amplitude varies with thrust force, introducing measurement errors
Solution Approach 1:
The patent implements a feedback mechanism where the thrust sensor continuously monitors the thrust force applied to the cam and feeds this information back to correct the angle sensor readings. The correction process adjusts the bridge circuit output values based on the measured thrust force, compensating for the amplitude variations. This feedback loop ensures that the angle detection remains accurate even when thrust force causes changes in the bridge circuit output amplitude.
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 system effectively suppresses changes in the angle sensor output due to thrust forces, enabling precise detection of rotation angle and torque by correcting for ripple errors.
Implementation Method 1
an angle sensor configured using a plurality of strain gauges... two sets of bridge circuits are configured by the plurality of strain gauges
Data Source
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AI summary
A wave reducer (1) includes a cam (41), a flex gear (30), an internal gear (20), an angle sensor (70), a thrust sensor (80), and a circuit (52). The angle sensor (70) is a sensor disposed in the flex gear (30) and having an output value changing in accordance with a rotation angle of the cam (41). The thrust sensor (80) is a sensor disposed in the flex gear (30) and having an output value changing according to a thrust force applied to the cam (41). The circuit (52) is electrically connected with the angle sensor (70) and the thrust sensor (80). The circuit (52) corrects an output value of the angle sensor (70) based on an output value of the thrust sensor (80).