This paper presents a distributed control framework for groups of wheeled mobile robots with significant (nonnegligible) vehicle dynamics driving on terrain with variable performance characteristics. A dynamic model of a high-speed robot is developed with attention to representation of wheelterrain performance characteristics. Using this model, aspects of distributed, cooperative control on unk...

Introduction: Curiosity has been traversing across the northern plains of Gale Crater since August 2012 and on 1/6/17 (Sol 1571) has traveled over ~15 km (based on wheel odometry). The rover is approaching a prominent hematite-bearing ridge, which it will ascend to make measurements, thereafter continuing south up the slopes of Mount Sharp. Curiosity has already encountered multiple mobility is...

For the six-wheel CRAB rover, this paper presents the torque control with Kriging estimation to improve the terrainability by minimizing wheel slip. In previous works, we presented a torque control approach, effectively improving terrainability by minimizing the variance of the required friction coefficient based on the static model. Using a Kalman filter to estimate the velocity information, a...

We present a hybrid systems solution to the problem of trajectory tracking for a four-wheel steered four-wheel driven mobile robot. The robot is modelled as a non-holonomic dynamic system subject to pure rolling, no-slip constraints. Under normal driving conditions, a nonlinear trajectory tracking feedback control law based on dynamic feedback linearization is sufficient to stabilize the system...

This paper describes a dynamic model and crosscoupling control of a mobile robot with four independently steered and driven wheels. The dynamic model incorporates the components of the wheel mechanisms, backlash effects of the wheel actuators and nonlinear forces produced by the tire-ground interaction. The problem of computationally efficient control of the vehicle is solved using a low-level ...

This paper investigates the path tracking problem for an electric vehicle which has four electromechanical wheel systems under normal and faulty conditions. With considering wheel slip constraints and certain actuator faults, a passive fault-tolerant controller based on variable structure control is developed to maintain the system stability and guarantee the acceptable tracking performance. Th...

An approach to estimate the tire{road friction during normal drive using only the wheel slip, that is, the relative diierence in wheel velocities, is presented. The driver can be informed about the maximal friction force and be alarmed for sudden changes. Friction related parameters are estimated using only signals from standard sensors in a modern car, and the physical relation between these p...

In this paper, two control approaches are presented for exploration rovers traversing sandy-sloped terrain. One of the proposed controls is a model-based feed-forward control using a characteristic diagram, called a Thrust-cornering characteristic diagram. It consists of various characteristic curves of wheel forces for varied wheel slip conditions. An appropriate steering maneuver for slope tr...

This paper presents analytical models to investigate the steering maneuvers of planetary exploration rovers on loose soil. The models are based on wheel-soil interaction mechanics, or terramechanics, with which the traction and disturbance forces of a wheel are evaluated for various slip conditions. These traction forces are decomposed into the longitudinal and lateral directions of the wheel. ...

This application note focuses on a design based on National Semiconductor’s patented NeuFuz based neural-fuzzy technology to arrive at a slip control scheme implemented on National Semiconductor’s low-cost COP8TM microcontroller. NeuFuz technology allows for the automated generation of a fuzzy logic control engine based on training data. In this case, the training data was taken from the well k...