Lift-button detection and recognition for service robot in buildings

Lift operation is one of critical functions for mobile service robot to move across levels in buildings. Lift operation poses the problem of lift-button detection and recognition for computer vision. This paper presents a framework for vision-based lift-button detection and recognition. This problem is challenging due to reflection and complex background. To achieve the robustness in lift operation, we adopt multiple techniques to combat the challenges. First, we propose a multiple partial models method to increase the robustness of button panel detection. Second, we do button recognition by combining structural inference, Hough transform, and multi-symbol recognition techniques. Lastly, we use ultrasonic distance measure devices to aid the vision of the robot. The experimental results show that our framework can achieve the promising results in recognizing both the internal and external buttons of lift.