|A nonholonomic motion planner for mobile manipulators moving in cluttered environments is presented. The approach is based on a discontinous feedback law under the infuence of a special potential eld. Convergence is shown via Lyapunov's direct method. Utilizing redundancy, the methodology allows the system to perform secondary, connguration dependent, objectives such as singularity avoidance. ...

This work is devoted to planning and execution of complex missions in Robotics. Robotics has evolved from an industrial, repetitive framework to application domains with much more variability of tasks, with increasing complexity in uncertain environment. This is clearly the case for Service Robotics e.g. but even industrial robots have now to work in environment not totally calibrated for the t...

We consider the kinematics of a mobile manipulator that consists of a non-holonomic (or holonomic) mobile platform and a holonomic manipulator mounted atop of the platform. At any fixed time instant and with fixed initial state of the platform these kinematics are viewed as a map from a Hilbert space of controls and manipulator’s joint positions into a taskspace of the mobile manipulator, and c...

Dynamic stability is an important issue for vehicles which move heavy loads, turn at speed, or operate on sloped terrain. In many cases, vehicles face more than one of these challenges simultaneously. This paper presents a methodology for deriving and reacting to proximity to tipover for autononmous field robots which must be productive, effective, and self reliant under such challenging circum...

Mobile manipulators operating in eld environments are susceptible to dangerous and costly rollover or tipover instabilities, particularly when operating over uneven terrain or when exerting large forces or moments. By monitoring the static and dynamic tipover stability margins of a mobile manipulator it is possible to predict such tipovers and take appropriate actions to prevent the tipover fro...