Automatic mechanical arm calibrating method and device

Abstract

The invention provides an automatic mechanical arm calibrating method and device. The automatic mechanical arm calibrating method comprises the steps of constructing a pixel coordinate system based ona camera and a geodetic coordinate system based on a base of a mechanical arm; calibrating the geodetic coordinate system and the pixel coordinate system, and obtaining scale parameters for converting the geodetic coordinate system and the pixel coordinate system and a mechanical arm moving range within which a marker can be photographed; obtaining point location information when the camera is located over the marker under at least three different rotating angles of the mechanical arm; calculating a relative location parameter of the central position of the camera and the position of an axisend; obtaining point location information of a marking point at different positions under the same rotating angle of the mechanical arm, wherein the marking point is a fixed point on the marker; and calculating coordinate calibrating parameters according to the point location information. According to the automatic mechanical arm calibrating method and the automatic mechanical arm calibrating device, the calibrating procedure is simplified, time for calibrating the geodetic coordinate system and the pixel coordinate system is greatly shortened, the calibrating precision is improved, and the operational barriers are lowered.

Description

technical field [0001] The invention relates to the field of calibration of a tool coordinate system, in particular to a method for automatic calibration of a mechanical arm and a calibration device. Background technique [0002] Industrial robot is a typical representative of mechatronics. It has been widely used in all walks of life in industry to continuously improve production efficiency. With the continuous development of robotics, computer technology and image processing technology, the application of industrial robots with vision systems is becoming more and more extensive. As the main way for industrial robots to obtain environmental information, the vision system can improve the identification and positioning capabilities of industrial robots and enhance the flexibility of industrial robots. In the application of industrial robots and vision systems, it is necessary to obtain the pixel coordinates of the marker T in the image through the vision system, and calculat...

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Problems solved by technology

[0006] 2. When obtaining the coordinates of the manipulator, if the tool carried by the robot is large or irregular, it is difficult to achieve alignment by human vision, resulting in an error in the transformation coefficient of the two coordinate systems, which affects the positioning of the marker object during operation

[0007] 3. Because this method only solves the coordinate transformation coefficient before the operation in the whole operation, and the error caused by other bad operations in the subsequent operation can only be corrected by stopping

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