Multi-Axis Kinematics Safety Compensation for Sensor Errors
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Solution Overview
Problem
Existing safety monitoring systems for multi-axis kinematics fail to adequately account for sensor errors and overtravel inaccuracies, leading to unnecessarily conservative operation and reduced availability due to pessimistic error calculations.
Innovation Solution
A method that incorporates specific error values and geometric parameters of the multi-axis kinematics system to dynamically calculate compensation values during operation, ensuring accurate safety function adjustments by considering sensor resolutions and overtravel distances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If general correction values are used without specific kinematics knowledge, then safety is ensured, but availability of the multi-axis kinematics is unnecessarily reduced
Solution Approach 1:
The patent applies local quality by transitioning from general correction values to specific correction values tailored to each individual multi-axis kinematics system. The system determines correction values based on the actual sensor characteristics, kinematic parameters, and error sources of the specific system being monitored, rather than applying blanket conservative corrections to all systems. This localized approach maintains safety while avoiding unnecessary availability reductions.
Solution Approach 2:
The patent implements parameter changes by dynamically adjusting correction values based on actual system parameters including sensor resolutions, measurement uncertainties, and kinematic chain characteristics. The system calculates specific correction values for each axis and their combinations, changing from static general corrections to dynamic parameter-specific corrections that reflect the actual system behavior and error sources.
2Reliability
If conservative safety monitoring is implemented to account for all possible errors, then safety is improved, but system performance and availability are reduced
Solution Approach 1:
The patent applies dynamics by transitioning from static conservative safety margins to dynamic correction values that adapt to actual system conditions. The system continuously determines correction values based on real-time axis positions, sensor characteristics, and kinematic parameters, allowing safety monitoring to be as restrictive as needed while permitting more liberal operation when actual errors are smaller than worst-case assumptions.
Solution Approach 2:
The patent implements feedback by using actual system measurements and sensor data to refine correction values. The system monitors actual positioning errors and uses this information to adjust correction values, creating a closed-loop approach that maintains safety while avoiding overly conservative restrictions based on outdated or generic error assumptions.
3Reliability
If dynamic safety zones are enlarged to account for sensor errors and overtravel, then safety is improved, but the workspace available for operation is reduced
Solution Approach 1:
The patent applies segmentation by breaking down the safety correction into individual axis contributions rather than applying a single large conservative margin to the entire workspace. The system calculates correction values for each axis based on its specific sensor resolution, overtravel characteristics, and kinematic role, then combines these segment-level corrections to determine the total safety margin, resulting in tighter and more accurate safety zones.
Solution Approach 2:
The patent implements another dimension by considering the dimensional contributions of each axis separately and combining them vectorially or through kinematic transformation matrices. Rather than adding safety margins in a simple scalar manner, the system accounts for how errors propagate through the kinematic chain in different spatial dimensions, resulting in more precise safety zone definitions that preserve workspace in directions where errors have minimal impact.
Data Source
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AI summary
The invention relates to a method and an associated control system for the safe operation of a multi-axis kinematic system using a safety function. This involves calculating compensation values during the runtime of the multi-axis kinematic system's control, wherein the calculation is performed depending on predefinable error values of the respective axes, geometric parameters of the multi-axis kinematic system, and current axis values of the multi-axis kinematic system, and operating the safety function based on the calculated compensation values.