As populations and the demand for higher crop yields grow, so to does the need for efficient agricultural wheeled mobile robots. To achieve precise navigation through a field it is desirable that the control system is designed based on an accurate dynamic model. In this paper a control affine model for a custom designed skid-steer differential drive wheeled mobile robot is found. The Terramechanic wheel terrain interaction is adopted and modified to consider wheels with a torus geometry. Varying slip ratios and slip angles are considered in the terrain reaction forces, which is curve-fitted using a nonlinear least squares approach such that the achieved model is control affine. The parameters in the proposed model is identified through an extended Kalman filter so that the state variables in the model are matched. Both simulation and experiments in a commercial farm validated the proposed model and the identification approach.
Master of Science in Aerospace Engineering (M.S.A.E.)
College of Engineering and Computer Science
Mechanical and Aerospace Engineering
Aerospace Engineering; Space System Design and Engineering
Length of Campus-only Access
Masters Thesis (Open Access)
Menendez-Aponte, Pablo, "Approximated Control Affine Dynamics Mode For an Agricultural Field Robot Considering Wheel Terrain Interaction" (2016). Electronic Theses and Dissertations. 5323.