Simulation model of mobile robot movement on complex ground

BACKGROUND: Typically, mobile robots shall have high maneuverability, requiring additional drives that allow for changing the propulsion unit geometry and complex motion control systems. Existing software used to simulate the movement of rigid body systems do not always allow for the accurate description of the propulsion unit (wheels) interaction with the complex ground, challenging the development of advanced control algorithms. AIM: To develop a movement simulation for mobile robots, combining the advanced software for mathematical modeling of rigid body system movement and an algorithm to detect the contact of wheels with the ground relief based on a modified GJK algorithm. METHODS: The approach proposed to solve the problem of propulsion unit contact with track irregularities is based on the GJK algorithm used to search for wheel intersections with the ground relief. The output of the algorithm allowed to determine contact forces and moments that describe the tire–ground interaction based on its elastic damping and traction properties. RESULTS: The authors propose a mathematical model of the wheel interaction with uneven ground for multiple contact points. The model is based on a modified GJK algorithm and allows to determine contact points and interaction forces when simulating the mobile robot movement at a speed close to real time. The paper presents an assessment of the model’s effectiveness and its suitability for developing automatic movement control algorithms for mobile robots. CONCLUSION: The developed model allows to study efficiently the mobile robot movement when negotiating large obstacles and uneven grounds with multiple contact points of the propulsion unit with the ground. The study confirms that the model is suitable for and may be used in mathematical simulation models to design motion control laws for a mobile robot.