A new pose measurement method based on microlens arrays

In pose measurement where infrared marking point is adopted as feature identification, only point coordinate information can be provided. In order to improve the accuracy of pose measurement, it is necessary to increase the number of feature points involved in pose solving, which limits the application of pose measurement method. A new pose measurement method based on two-dimensional optical coding marking orientation is designed. In the process of measurement, not only the coordinate information of the marking point can be used, but also the orientation information of the visual sensor to shoot the marker can be obtained, which improves the accuracy of pose measurement. The optical marker in this method includes a microlens array, a back two-dimensional code pattern and a background light source. When the visual sensor shoots the optical marker from different angles, different two-dimensional coding patterns can be obtained, which provides orientation information for pose measurement. Firstly, the images captured from different viewpoints are preprocessed, including segmenting the optical marker with the surrounding environment and transforming the images into undistorted frontal views. Then, on the basis of the pixel information of the microlens array's surface pattern, every single microlens for different viewpoints is encoded to obtain a set of code strings varying with the viewpoint. Finally, the code string information of different viewpoints is processed and the orientation model of two-dimensional optical coding marker is established. In addition, the factors that may impact the pose measurement accuracy are evaluated.