Design and experiment of distance measuring system with single camera for picking robot

The task of vision system is to discern and position the target from growing environment for vegetables picking robot and provide kinematical parameter for the manipulator. Distance measuring is not only an important factor in influencing the positioning accuracy of picking target but also a difficulty for in the research of picking robot. For this reason, a new method of measuring distance by means of single camera for picking robot is suggested. The dual threshold is adopted to segment the G-B gray images of the target. The object´s characters, such as outline, area, center of gravity, enclosing rectangle and the point to cut off, are distilled through contour tracing. The width d of eggplant image at two location and the motion distance of the manipulator along optical axis are obtained separately, and then the distance z between the camera and the eggplant. Testing soft is programmed based on Visual C++ 6.0 according to the measuring distance theory. Experiments explain that the measure error is within ±18mm when the measure distance ranges from 275mm to 575mm.