Stairs are one of the main obstacles faced by indoor mobile robots. It is necessary to estimate the pose of the robot relative to the stairs during the climbing process. Most indoor positioning methods are applied to a two-dimensional space plane

and climbing stairs is a movement in three-dimensional space. Compared with the addition of height displacement in two-dimensional space

this brings great challenges to pose estimation. A pose estimation method for robots climbing stairs based on two-dimensional images and partial depth information is proposed in this paper. The method takes advantage of the characteristics of the intersection of the edge line of the horizontal staircase and the edge line where the height and width of the stair step are located

and proposes a three-line intersection method to detect the edge point of the staircase. Then combine the depth information of the edge point to get its three-dimensional coordinates in the camera coordinate system

and use the coordinates to establish the staircase coordinate system and solve the pose. At the same time

the periodic variation characteristic of the distance from the edge point to the camera is used to count the steps of walking stairs. Finally

the kinect camera is used to move on the stairs to simulate the climbing of the robot and the proposed method is tested. The results show its effectiveness and practicability.