Abstract
One of the challenges in terrestrial mobile robotics is the navigation of robots over uneven terrain composed of inclined surfaces and obstacles. During this task, the robot may tip over, get stuck, or slide down when moving on inclined surfaces. In this work, a novel metric is developed to predict the total slip risk of wheeled mobile robots when overcoming obstacles formed by inclined surfaces. This metric, called the slip index, was derived by analyzing friction forces, calculating instantaneous friction coefficients, and estimating the direction angle of the friction forces on each wheel, using an innovative approach. With this model, it will be possible to evaluate the robot's propensity to slip on inclined obstacles even before the robot moves over them, as long as certain geometric and physical characteristics of the obstacles are known beforehand. In this sense, the proposed index was validated through simulations and real-world tests, demonstrating efficient slip risk prediction with high accuracy, as evidenced by a low mean absolute percentage error (MAPE). This metric is a valuable tool for predicting imminent slip conditions, designing navigation strategies in uneven environments, and improving the robot's interaction with its surroundings.