A method and controller for improving color mark detection accuracy

Abstract

The embodiment of the invention provides a method for improving the detection precision of a color mark and a controller, the method is used for accurately identifying the position of the color mark on a material and improving the detection precision of the color mark. The method in the embodiment comprises the following steps: recording a moment when a color mark signal transmitted by a color mark sensor produces the state change of a preset type if the color mark signal has the state change of the preset type within the current control period, wherein the state change of the preset type is used for indicating that the color mark on the material passes through a preset detection area; calculating a time interval t1 between a current moment T2 and the moment when the state change of the preset type occurs; calculating a distance L1 that the color mark on the material moves within the time t1; acquiring a position coordinate X2 of the material on the current moment T2; and subtracting the distance L1 from the position coordinate X2 to obtain a first calibrated position coordinate of the material after the color mark is calibrated.

Description

technical field [0001] The invention relates to the technical field of automatic detection, in particular to a method and a controller for improving the detection accuracy of color marks. Background technique [0002] In order to ensure that the packaging materials have a complete and specific pattern, corresponding color stripes, also called color dots, will be printed on the raw materials. Most of the existing packaging materials are cut according to the color mark points. With the rapid development of the packaging industry, the requirements for cutting speed, precision and efficiency are getting higher and higher, and the algorithm of color mark detection and tracking will affect the Cutting precision and efficiency. [0003] The current color mark detection is generally based on the controller periodically scanning the color mark signal received by the IO port to determine the position of the color mark, for example, the middle point within the coordinate range within ...

AI Technical Summary

Problems solved by technology

In the existing detection method, when the interval between two scans of the controller cannot be reduced, the accuracy of color mark detection is fixed

For example, the control period is 100us~2ms, and the control period of the IO port of the PLC is longer. For example, the moving speed of the color mark is 300m / min. Even if the IO port has the fastest detection speed of 100us, that is, within the detection window of 100us, the middle detection point is taken. (at 50us), if the actual color mark position deviates from the middle detection point, the detection will lead to a deviation in the detection accuracy, and the detection error is ±0.25mm. Such detection accuracy is not allowed in the application of high-speed equipment

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