Positioning Technology of Apple-Picking Robot Based on OpenCV

To improve the positioning accuracy of the vision system for apple-picking robot, a method characterized by a marker to recover the spatial location of the apple is proposed. Then the spatial location of the apple obtained with the stem as the matched point is accomplished to get its corresponding depth value of different working distances. Finally, the measured distance with the marker is as a reference to analyze error for stem ranging. The result shows that the average relative error with the marker is 0.63% while that with the stem is 2.97% when the working distance is in range of 300-900mm, which can meet the requirements of apple picking robot in most working circumstances.