Tracker Calibration Device Aligning Independent Coordinate Systems
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Solution Overview
Problem
Calibrating multiple types of trackers simultaneously is challenging due to their use of independent coordinate systems, leading to significant errors when assuming they are at the same position, and requires troublesome advance measurements of relative positions.
Innovation Solution
A tracker calibration apparatus and method that includes data acquisition and estimation sections to convert positions from one coordinate system to another without prior measurement of relative positions, using sample data generation to estimate parameter values for alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If calibration is performed assuming multiple tracker types are at the same position, then calibration process is simplified, but calibration accuracy deteriorates significantly
Solution Approach 1:
The system performs preliminary action by having the second tracker measure the position and orientation of the first tracker before calibration. This advance measurement allows the calibration process to account for actual relative positions rather than assuming they are at the same position, thereby maintaining calibration accuracy while keeping the process simple.
Solution Approach 2:
The first tracker serves as an intermediary object that the second tracker measures. By using the first tracker as a reference target that the second tracker can observe and measure, the system establishes a relationship between the two trackers' coordinate systems without requiring complex direct measurement or assumption of coincident positions.
2Measurement precision
If advance measurements of relative positions are performed to suppress calibration errors, then calibration accuracy is improved, but operational complexity increases
Solution Approach 1:
The system implements self-service by having the trackers perform measurements autonomously during normal operation. The second tracker automatically measures the first tracker's position and orientation, and this data is automatically used for calibration parameter calculation, eliminating the need for manual advance measurements or complex external measurement equipment.
Solution Approach 2:
The system uses feedback by continuously measuring the first tracker's position and orientation with the second tracker, then using this measured data to calculate and update calibration parameters. This closed-loop approach ensures high calibration accuracy without requiring complex preliminary setup procedures.
3Adaptability or versatility
If multiple types of trackers with independent coordinate systems are used together, then tracker functionality and versatility are improved, but calibration complexity increases
Solution Approach 1:
The calibration method achieves universality by working with any combination of tracker types that have independent coordinate systems. The approach uses general measurement and transformation principles that can be applied regardless of the specific tracker technologies involved, enabling multi-functional compatibility across different tracker types.
Solution Approach 2:
The system manages coordinate system alignment by changing parameters - specifically, it calculates transformation parameters (rotation and translation) that convert coordinates from one tracker's independent coordinate system to another. This parameter-based approach simplifies the complexity of dealing with multiple coordinate systems by reducing it to mathematical transformations.
Data Source
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AI summary
Provided are a tracker calibration apparatus, a tracker calibration method, and a program that make it possible to accurately calibrate a plurality of types of trackers without measuring their relative positions in advance. A tracker data acquisition section (50) acquires a plurality of pieces of first tracker data. The first tracker data indicates the position of a first tracker that is expressed in a first coordinate system. The tracker data acquisition section (50) acquires a plurality of pieces of second tracker data. The second tracker data indicates the position of a second tracker that is expressed in a second coordinate system. Based on the plurality of pieces of the first tracker data and the plurality of pieces of the second tracker data, a parameter estimation section (58) estimates parameter values for converting the positions expressed in the second coordinate system into expressions in the first coordinate system and the relative position of the second tracker relative to the first tracker.