Position Control Using Encoder-Image Interpolation for Fast Alignment
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Solution Overview
Problem
Existing position control methods in factory automation face challenges in achieving high-speed and highly accurate positioning due to delays in image processing, requiring complex corrections and initial value settings, which are not suitable for high-speed applications.
Innovation Solution
A control device with a position determination unit that estimates the control object's position using a combination of encoder values and image processing data, allowing for real-time corrections and interpolation to align the control object with the target position, thereby simplifying the processing and improving accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If image processing is used to measure distance, then positioning accuracy can be improved, but processing delay occurs affecting control speed
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing the relationship between encoder values and image processing results in a lookup table before actual control operations. During real-time control, the system quickly retrieves pre-computed correction values based on current encoder readings, avoiding the need for time-consuming image processing calculations during the control cycle. This allows the system to maintain high positioning accuracy while achieving fast response times suitable for high-speed control applications.
2Measurement precision
If Kalman filter is used for correction, then positioning accuracy can be improved, but system complexity and difficulty of setup increase
Solution Approach 1:
The patent replaces the complex Kalman filter with a simpler correction mechanism based on pre-computed lookup tables and basic interpolation algorithms. Instead of maintaining a complex state estimation model with multiple parameters and initial value settings, the system uses lightweight correction values derived from comparing encoder-based position estimates with image processing results. This simplified approach achieves comparable positioning accuracy without requiring expert configuration or complex computational resources.
3Speed
If encoder values only are used for positioning, then high-speed control can be achieved, but positioning accuracy is limited
Solution Approach 1:
The patent introduces an intermediary correction mechanism that bridges encoder-based fast control and image processing-based accurate measurement. The system uses encoder values for real-time position feedback and control speed, while simultaneously using image processing results as a reference to compute correction values. These correction values act as an intermediary that compensates for encoder errors without slowing down the control loop, thereby maintaining both high control speed and improved positioning accuracy.
Data Source
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AI summary
A control device, a position control system, a position control method, and a recording medium are provided. The controller includes a feedback control unit and a position determination unit. The position determination unit acquires an encoder values from a driver at a cycle. The position determination unit acquires a measurement position obtained by measuring a positional relationship between a control object position and a target position by image processing, at a time interval that is longer than the cycle. The position determination unit determines an estimation interpolation position corresponding to the control object position by using the encoder value and the measurement position. The feedback control unit outputs control data for aligning the control object position at the target position by using the estimation interpolation position determined by the position determination unit to the driver.