A WSNs-based Approach and System for Mobile Robot Navigation

Mobile Robots are expected to do some routine or danger tasks automatically for human in many situations. Among the techniques related to the Mobile Robot, localization and navigation are the core techniques for Mobile Robots to realize true intelligence and complete autonomous moving. J. J. Leonard and H. F. Durrant-Whyte summarized the problem of navigation into answering the following three questions (Leonard & Durrant-Whyte, 1991) : “where am I? ”. “where am I going?” and “how should I get there”. The first question lies to identifying the current location of the robot. The second and third questions are related to the capability of environment perceiving and path planning. The navigation methods that are frequently used in Mobile Robots mainly include inertial navigation, visual navigation, sensor-based navigation and satellite navigation. Among the satellite navigation systems that are in use, the Global Positioning System (GPS) (Bock & Leppard, 1990) gives the most accurate information. But in some cases, the satellite system cannot or should not be used. To solve this problem, Wireless Sensor Networks (WSNs) was introduced into this area. In this chapter, a new navigation approach is proposed based on the localization function of Wireless Sensor Networks as a supplement to current navigation methods. The WSN can obtain various types of information about the environment such as the temperature, the humidity and the slope of the ground, and the proposed approach then use them to help the decision-making in navigation and path planning. The chapter mainly includes 3 sections. The first section is about map building. A WSNbased method for environment modelling and map building was proposed. This method utilized the distributed environment information obtained by the WSN to establish the environment model and the grid map with multiple attributes. Simulative analysis showed that the environment model established by this method achieved good match result on the map. In section 2, the dynamic monitoring function of WSN was utilized to adapt the Mobile Robot to the requirement of navigation on the changing environment. An on-line path planning method based on WSNs was proposed. Using this planning method, the Mobile Robot could make trade-off between safety and efficiency through adjusting the parameters used in the algorithm. At last, an experimental WSN-based Mobile Robot 23