Optimum Placement of Wireless Access Point for Mobile Robot Positioning in an Indoor Environment

The Wireless Positioning System (WPS) has gained increasing attention for mobile robot applications in indoor environments over conventional on-board sensors. This is mainly due to their cost effectiveness as well as adaptability for future use. Many literatures on WPS adapted existing wireless infrastructures such as WiFi for mobile robot usage, resulting in relatively impractical accuracy for mobile robot application. A systematic technique must be sought in order to place the wireless nodes where coverage could be maximized and be suitable for a mobile robot positioning system via fingerprinting technique. We propose an effective and simple means to optimize wireless access point (AP) placement. Simulation results by ITU-R P.1238 MWF signal propagation model with automatic wall crossing computation have ensured the maximum coverage for human users using a minimum number of wireless nodes as possible. The mobile robot positioning error employing the weighted k-nearest neighbor algorithm(WKNN) with the average signal strength as fingerprint database yielded significant results when the proposed placements are used over symmetrical placements.