Object Outline and Surface-Trace Detection Using Infrared Proximity Array

In this paper, a method of detecting object outlines and creating surface traces using a low-cost distance measurement array of infrared light-emitting diode (LED)-photodiode pairs is demonstrated. For each active LED, the light level on the corresponding photodiode may be measured, generating an image of distance values whose pixel resolution is limited to the spacing between LED-photodiode pairs. Moreover, using several photodiodes to detect the reflected light from each LED, lateral resolution is enhanced, and the angle of reflection can also be detected. Experimental results demonstrate successful application of such data to detecting object outlines and surfaces, and show promising possibilities in using the array for simultaneous localization and mapping (SLAM). The developed sensor array is best suited for environments where prior information of object distance is available (e.g., production lines), or where only relative distance information is needed. In addition, the speed and low cost of the array makes it a good supplementary device to more precise, yet at the same time slower and more expensive distance measurement devices.