An improved kinematic model for skid-steered wheeled platforms

Dead reckoning in wheeled mobile platforms is a method that uses the kinematic model of the platforms to estimate their pose from the integration of the wheels’ motion. Due to its integrative principle, this method is very sensitive to modeling and measurement errors. Skid-steering platforms are no exception to this and although linear motions can be very well modeled, skid-based rotations depend on a number of factors, including the type of terrain and the location of the center of mass of the platforms, which are disregarded in conventional kinematic models. This article describes an improved kinematic model that takes these factors into account and verifies the model in a variety of working conditions, including different terrains and asymmetric loads, for two different wheeled skid-steered platforms. The obtained results show significant improvements in odometry performance using the proposed model in comparison to conventional approaches.