field capacity, fuel consumption and drive wheel slippage in massey ferguson (mf399) tractor with standard and liquid ballasted (630 kg) axle load and at 4wd mode was evaluated and compared. the tests were conducted at the experimental station, college of agriculture, shiraz university, in a field with clay loam soil at average moisture content of 18% d.b. the experiment was of a randomized com...

On-Line Optical Flow Feedback for Mobile Robot Localization/Navigation. (May 2003) David Kristin Sorensen, B.S., Texas A&M University Chair of Advisory Committee: Dr. Sooyong Lee Open-loop position estimation methods are commonly used in mobile robot applications. Their strength lies in the speed and simplicity with which an estimated position is determined. However, these methods can lead to i...

We describe in detail a novel kinematic simulation of a three-wheeled mobile robot moving on extremely uneven terrain. The purpose of this simulation is to test a new concept, called Passive Variable Camber (PVC), for reducing undesirable wheel slip. PVC adds an extra degree of freedom at each wheel/platform joint, thereby allowing the wheel to tilt laterally. This extra motion allows the vehic...

A challenging problem faced by wheeled mobile robots (WMRs) such as planetary rovers traversing loose sloped terrain is the inevitable longitudinal slip suffered by the wheels, which often leads to their deviation from the predetermined trajectory, reduced drive efficiency, and possible failures. This study investigates this problem using terramechanics analysis of the wheel-soil interaction. F...

In this paper, a robust wheel slip control system based on a sliding mode controller is proposed for improving traction-ability and reducing energy consumption during sudden acceleration for a personal electric vehicle. Sliding mode control techniques have been employed widely in the development of a robust wheel slip controller of conventional internal combustion engine vehicles due to their a...

This paper discusses the development of an optimal wheel torque controller for a compliant modular robot. The wheel actuators are the only actively controllable elements in this robot. For this type of robots, wheel-slip could offer a lot of hindrance while traversing on uneven terrains. Therefore, an effective wheel-torque controller is desired that will also improve the wheel-odometry and min...

Much research on two-wheeled robots has been completed in the past decade, but robot stability in low-traction environments has not yet been considered. A model for the two-wheeled robot including wheel slip effects is derived. A wheel slip dependent friction model is used to simulate two low-traction surfaces: the first has characteristics similar to ice and the second is frictionless, in addi...

A method for kinematics modeling of a six-wheel Rocker-Bogie mobile robot is described in detail. The forward kinematics is derived by using wheel Jacobian matrices in conjunction with wheel-ground contact angle estimation. Te inverse kinematics is to obtain the wheel velocities and steering angles from the desired forward velocity and turning rate of the robot. Traction Control also developed ...

A method for kinematics modeling of a six-wheel Rocker-Bogie mobile robot is described in detail. The forward kinematics is derived by using wheel Jacobian matrices in conjunction with wheel-ground contact angle estimation. The inverse kinematics is to obtain the wheel velocities and steering angles from the desired forward velocity and turning rate of the robot. Traction Control is also develo...