Robot Torque Measurement Device with Dual Redundant Strain Gauge Systems
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Solution Overview
Problem
Existing torque measurement technologies in robots are not sufficiently reliable and efficient, particularly in terms of space usage and component complexity, which affects the accuracy and reliability of torque detection in multi-axis robotic systems.
Innovation Solution
A measuring device with two separate torque measurement systems, each using strain gauges connected in bridge circuits, coupled with analog-to-digital and digital-to-analog converters, and Field Programmable Gate Arrays (FPGAs) for evaluation, which reduces wiring complexity and enhances reliability through redundant measurements and independent digital evaluation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two separate torque measurement systems are implemented for redundancy, then reliability is improved, but device complexity and space requirements increase
Solution Approach 1:
The patent combines two separate torque measurement systems into a single integrated device where both measurement paths share common components including the axle, evaluation unit, and power supply. This merging approach maintains the reliability benefits of redundant measurement while reducing overall device complexity and space requirements compared to completely separate systems.
Solution Approach 2:
The evaluation unit serves multiple functions by processing signals from both measurement paths and performing self-tests on all components. The single evaluation unit handles torque measurement, redundancy verification, and diagnostic functions, eliminating the need for separate evaluation devices for each measurement path.
2Reliability
If two separate torque measurement systems are implemented for redundancy, then reliability is improved, but the space required for installation increases
Solution Approach 1:
The patent integrates both measurement paths within the same physical space by sharing common components. The two measurement paths are combined in the evaluation unit which processes both signals, and both paths use the same power supply and mounting structure on the axle, significantly reducing the installation space compared to separate systems.
3Measurement precision
If strain gauges are used for torque detection, then measurement precision is improved, but the system becomes sensitive to temperature changes and requires additional compensation
Solution Approach 1:
The evaluation unit performs self-tests by switching between the two measurement paths and comparing their outputs. This feedback mechanism detects temperature-induced drift and other errors, allowing the system to compensate for environmental factors and maintain measurement precision without requiring separate temperature compensation circuits.
Solution Approach 2:
The system performs self-tests before actual torque measurement to establish baseline values and detect any temperature-induced offsets. By conducting preliminary diagnostics and comparing the two measurement paths under no-load conditions, the system compensates for temperature effects before taking measurements.
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 provides accurate and reliable torque measurement with reduced space requirements and minimal component complexity, enabling efficient and precise torque detection in robotic systems, particularly in multi-axis configurations.
Implementation Method 1
strain gauges, for example, whose ohmic resistances change when the strain gauge is stretched or compressed
Implementation Method 2
when the strain gauge is stretched or compressed
Implementation Method 3
a measuring device for determining a torque acting on an axle, which comprises a Wheatson bridge
Data Source
Figure 1~2
Figure 3
AI summary
The measuring device (20) has a unit (27) for producing analog electrical signal arranged to a torque. An analog to digital converter (29) is equipped for producing digitized signal at the unit. A digital evaluation unit (22) is equipped downstream to the analog to digital converter. An independent claim is also included for a robot with a control device.