A Static Calibration Method for Line Laser Sensor

Abstract

The invention relates to a static calibration method of a line laser sensor. The static calibration method comprises the following steps: (1) calibrating a laser plane in the vertical direction; (2) installation of a calibration tool; (3) calibrating each calibration circle on the calibration tool; (4) adjusting the position of the tail end of a robot; (5) collecting image information of the calibration tool in the moving process from the starting point to the ending point of the first scanning position; (6) collecting image information of the calibration tool in the moving process from the starting point to the ending point of the second scanning position; (7) fitting the calibration circles on the images acquired in the step (5) and the step (6); and (8) carrying out value fitting operation according to the coordinate of the calibration point on the calibration tool in an online laser sensor coordinate system and the coordinate of the calibration point in a robot coordinate system. According to the method, the problem of external parameter calibration of the linear laser sensor in the process that the linear laser sensor cannot be moved and used along with various movement mechanisms is solved, and the method is flexible, high in precision, high in speed, good in stability and small in calculated amount.

Description

technical field [0001] The invention belongs to the technical field of sensor calibration, and in particular relates to a static calibration method of a line laser sensor. Background technique [0002] With the rise of concepts such as industrial informatization and intelligent manufacturing in China, the industrial field has been undergoing continuous transformation and upgrading in recent years, and its development model is always keeping pace with the development of the times. Robots and smart sensors have been widely used in various industries, and may have become indispensable for many companies, thanks to their unique advantages and the benefits brought by their application. economic benefits. This trend will not change in the future. Robots and smart sensors will more and more replace human work, and at the same time be able to adapt to various production and manufacturing environments, and the environment is especially harsh for the foundry industry. Machine vision ...

AI Technical Summary

Problems solved by technology

[0006] The above calibration methods either require a special mechanical motion actuator to carry the calibration plate to move within the field of view of the laser camera, which requires an additional high-precision motion mechanism, or require multiple robots to work together to complete the hand-eye calibration. may not have so many bots available at the time

[0007] However, the method of non-contact calibration requires the robot to carry sensors to change multiple different poses and scan the calibration plate placed at the same position. Attitude control is difficult to control, and the calibration process is complicated. Without the help of a second robot and an additional motion actuator, it is necessary to install a tooling or workpiece with a known positional relationship at the end of the mechanical arm, and it is necessary to have multiple obvious features on the tooling or workpiece. , this method requires a lot of preparatory work in the early stage, requires additional specially designed equipment, and is difficult to operate when the robot carries the tooling and the line laser to scan the picture.

[0008] When using external tooling or workpiece for calibration, it is affected by the machining accuracy of the calibration point features, which affects the calibration accuracy

The calibration plate with fixed structure is more complicated in the image processing process. The calibration process is complicated. Due to the limitation of the field of view of the line laser, the range of motion of the movement mechanism is also limited during calibration, and the calibration accuracy is low, so this calibration method is used less.

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