Multi-Plane Calibration Jig for Single-Session Robot Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for calibrating robot systems using a cubic jig require multiple posture changes and imaging sessions, leading to inefficient parameter calibration due to the limited number of planes that can be accurately imaged in a single session.
Innovation Solution
A jig with N planes, where N is 4 or more, is designed with unique angles relative to a reference plane, allowing multiple planes to be imaged simultaneously by a stereo camera, enabling efficient calibration of parameters for associating image-derived positions with three-dimensional space coordinates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a cubic jig with three planes is used for calibration, then the structure is simple and easy to manufacture, but multiple posture changes and repeated imaging are required, increasing calibration time
Solution Approach 1:
The calibration jig is divided into multiple independent planes (N≥4), each with distinct normal vectors. This segmentation allows each plane to contribute independent calibration information, enabling accurate parameter determination from a single imaging session without requiring multiple posture changes.
Solution Approach 2:
The invention transitions from a three-plane cubic structure to an N-plane structure (N≥4) with normal vectors distributed in three-dimensional space. This dimensional expansion provides sufficient geometric constraints for accurate calibration parameters to be calculated from a single two-dimensional image, eliminating the need for repeated imaging.
2Ease of operation
If only three planes are imaged in one session, then the imaging process is simple, but calibration parameters cannot be accurately decided, requiring repeated imaging
Solution Approach 1:
Each plane in the N-plane jig has a unique normal vector that is not symmetrical with respect to other planes. This asymmetry ensures that each plane provides independent and non-redundant calibration information, allowing accurate determination of all calibration parameters from a single imaging session.
Solution Approach 2:
The N planes with unique normal vectors serve as intermediaries that bridge the two-dimensional image plane and the three-dimensional calibration space. By capturing images of these planes, the system can accurately compute calibration parameters without requiring multiple imaging sessions.
3Loss of information
If multiple posture changes are performed for imaging, then more calibration information can be obtained, but the calibration process becomes time-consuming
Solution Approach 1:
The N planes are pre-configured with unique normal vectors before the calibration process begins. This preliminary arrangement ensures that all necessary calibration information is contained within a single jig configuration, allowing complete calibration to be achieved from one imaging session without requiring subsequent posture changes.
Solution Approach 2:
The N-plane jig serves multiple functions simultaneously: each plane provides independent calibration data, and collectively they provide sufficient constraints for determining all calibration parameters. This multi-functionality eliminates the need for multiple specialized imaging sessions, significantly improving calibration efficiency.
Data Source
AI summary
A jig according to the present disclosure includes N planes (N is an integer equal to or larger than 4) respectively attached with patterns, in which−90°<θ<90° (1)0≠0 (2)where θ is an angle formed by, with respect to a reference normal vector perpendicular to a jig reference plane, the jig reference plane being one plane among the N planes, and having a direction from the jig reference plane toward a space in which the stereo camera is disposed, a non-reference normal vector perpendicular to a non-reference plane different from the jig reference plane among the N planes and having a direction from the non-reference plane toward the space in which the stereo camera is disposed. Non-reference normal vectors corresponding to N−1 non-reference planes among the N planes have directions different from one another with respect to the reference normal vector and do not have directions symmetrical with respect to the reference normal vector.