Research On Grid Map Building Method Of Indoor Environment Based On Sonar

Map building accounts for the problem of acquiring spatial models of physical environments through mobile robots. The problem of map building is generally regarded as one of the most important problems in the pursuit of building truly autonomous mobile robots. Despite significant progress in this area, it still reserves great challenges.The author has mainly studied on the related method based on grid map building of indoor environment of mobile robot. It takes the mobile robot MORCS-2 as experiment platform, which is developed by Central South University Intelligent Lab. The main contribution and work of this paper are described as follows:1 Using the sonar, speedometer equipped, mobile robot can get data of obstacle and robotic state, and there are three models to be founded in system of mobile robot, including pose model, movement model and control order model. The date from speedometer will be corrected by these three models, so we can correct the accuracy of mobile robot's pose in the process of map building.2 The author introduces the basic idea of Bayesian rule, and it takes Uniform Distribution Model as the sonar model. This paper proposes a probabilistic method of grid map building based on MORCS-2 in experiments, and in the process of the local map transforming to the global map, since the usual method belongs to Bayesian rule, what's more, the kind of methods need tremendous calculational resource. However the method that this paper brings forward only need use 0-1 probability, so planar transition apply to the data of local map more easily. It can assure the precision of grid map building, and it can reduce the affection of noise.3 Although sonar sensors are fairly accurate in measuring distance from object to robot, they have some errors on estimating the azimuth of object.In allusion to the indoor environment. The author puts forward a method for improving the accuracy of map building using mobile robot based on ATM (The Arc-Transversal Median Algorithm) method. So referencing the ATM Method, we setup the spectrum of the tangent's angles, and especially introduce the weight for it.