Identification marks (or the fiducial markers) recognition is an important problem in image processing. This technique is used in robotics and industry to perform loading and unloading operations. Usually, algorithms using the neural networks to solve this problem show their low efficiency in devices with low computing resources. The proposed method is based on comparing the mark contour with an ellipse and converting the camera coordinates and contour parameters into the physical ones. So, it becomes possible to recognize the circular identification marks in space and to to perform the robot positioning without using large computing resources. The algorithm based on the proposed method was implemented on the Raspberry PI 3B quad core ARM Cortex-A53 in the 1.2 GHz single-board computer and an OV5647 camera. The algorithm showed acceptable positioning accuracy for solving tasks related to loading and unloading packaging units by autonomous robots without human intervention.