Linear Drive Sensor Offset Calibration for Positioning Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Motion control systems using linear drives face variations in position feedback signals due to manufacturing and assembly tolerances, leading to positioning errors and ripple in the control signals, which affect the accuracy of mover positioning along the track.
Innovation Solution
A system that automatically calibrates gains and offsets for each position feedback signal by recording and comparing peak values against a target peak value, and periodically updates sensor gains and offsets to minimize variations between sensors, ensuring accurate position feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If position sensors are used to detect mover location, then position feedback is provided to the controller, but manufacturing and assembly tolerances cause variations in feedback signal amplitude leading to positioning errors
Solution Approach 1:
The system uses feedback from position sensors to detect mover location and automatically adjusts sensor gains based on the amplitude of feedback signals. The controller monitors the feedback signals and modifies sensor gain values to compensate for variations caused by manufacturing and assembly tolerances, thereby maintaining positioning accuracy despite component variations.
Solution Approach 2:
The system dynamically changes the parameter of sensor gain values based on the amplitude of position feedback signals. By adjusting the gain parameter in response to measured signal characteristics, the system compensates for amplitude variations and maintains consistent positioning accuracy across different sensors and operating conditions.
2Loss of information
If the controller uses amplitude of position feedback signals to determine mover location, then position information is obtained, but variations in amplitude cause variation in detected position
Solution Approach 1:
The controller continuously monitors position feedback signals and uses this feedback to automatically adjust sensor gains. This closed-loop approach ensures that amplitude variations are compensated in real-time, maintaining accurate position information without loss despite variations in signal amplitude.
Solution Approach 2:
The system changes the sensor gain parameter dynamically based on the amplitude of feedback signals. By adjusting this parameter, the system normalizes the position feedback and eliminates the relationship between signal amplitude variations and position detection errors, preserving position information accuracy.
3Measurement precision
If multiple position sensors are spaced along the track, then mover position can be detected at multiple locations, but variations between adjacent sensors introduce step changes and ripple in position feedback
Solution Approach 1:
The system uses feedback from all position sensors to detect mover location and automatically adjusts each sensor's gain based on its feedback signal amplitude. This ensures that adjacent sensors operate with normalized gain values, eliminating step changes and ripple in the position feedback while maintaining smooth and continuous position information across the entire track.
Solution Approach 2:
The system dynamically adjusts the gain parameter for each position sensor based on its measured feedback signal characteristics. By normalizing the gain values across all sensors, the system eliminates discontinuities and ensures smooth, continuous position feedback from adjacent sensors, maintaining stability in the position detection system.
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 solution reduces positioning errors and ripple in the control signals, enhancing the accuracy and reliability of mover positioning along the track by compensating for variations in sensor feedback, thereby improving the overall performance of the linear drive system.
Implementation Method 1
the controller uses the amplitude of the position feedback signal to determine a location of the mover with respect to the position sensor generating the feedback signal
Implementation Method 2
Successive activation of the coils establishes a moving electromagnetic field that interacts with the movers and causes the mover to travel along the track
Data Source
AI summary
A system automatically calibrates gains and/or offsets for each position feedback signal in order to reduce variations between position feedback signals for each sensor in a linear drive system. As a mover travels along a track segment, the segment controller records the position feedback signal output from each position sensor corresponding to a magnet on the mover passing the position sensor. The segment controller periodically monitors the position feedback values generated by one mover as it travels along the track segment and automatically updates the sensor gains as a function of a ratio of a target peak value to a measured peak value of the position feedback signal. The segment controller also records the position feedback signal from each sensor when no mover is traveling past the sensor. The segment controller periodically monitors the position feedback values received when no mover is present and automatically updates sensor offset values.