Swedish wheeled mobile robots have remarkable mobility properties allowing them to rotate and translate at the same time. Being holonomic systems, their kinematics model results in the possibility of designing separate and independent position and heading trajectory tracking control laws. Nevertheless, if these control laws should be implemented in the presence of unaccounted actuator saturatio...

Among control problems for mobile robots, point-to-point stabilization is the most challenging since it does not admit designs with smooth static state feedback laws. Stabilization strategies for mobile robots, and nonholonomic systems generally, are smooth, time-varying or nonsmooth, time-invariant. Time-varying control strategies are designed with umdamped linear oscillators but their fixed s...

Mobile manipulators have been given extensive attention in recent years since they have many applications such as materials transport and service for disabled persons. A mobile modular manipulator is normally composed of an m-wheeled mobile platform and an n-degree-of-freedom (DOF) onboard modular manipulator. This combination extends the workspace of the entire robot dramatically. Building up ...

In this work, we consider a group of differential-wheeled robots endowed with noisy relative positioning capabilities. We develop a decentralized approach based on a receding horizon controller to generate, in real-time, trajectories that guarantee the convergence of our robots to a common location (i.e. rendezvous). Our receding horizon controller is tailored around two numerical optimization ...

Omni-directional mobile robots have been popularly employed in several application areas. However, the kinematics for these systems have not been clearly identified, specially for redundantly actuated case which is common in omni-directional mobile robot such as Nomadic model. For such mobile robot systems, exploitation of redundant actuation as well as singularity analysis has not been extensi...

The UMASS uBot-4 is a two wheeled, dynamically stable, bimanual mobile manipulator. It is a compact, safe, and cost effective platform with many features such as whole body postural control, force sensing actuators, two 4-DOF arms, and a small footprint. It is the latest in a series of small mobile robots that originated with the uBot-0.5 (ca. 1997). This paper presents the motivations for the ...

Obstacle avoidance is an essential function for the navigation of mobile robots. Noise filtering improves the measurement accuracy of senors and plays an important role for obstacle avoidance in the applications of mobile robots. This study evaluates the performance of the extended Kalman filtering (EKF) and Kalman filtering (KF) for obstacle avoidance of a two-wheeled mobile robot. EKF is an a...

We report here the holonomy analysis of three wheeled mobile robots. Two of these, Vuton II and Nomad, have full mobility and are claimed by their inventors to be holonomic. We show that, in fact, they are nonholonomic. Nevertheless, conditions are given under which these robots can be designed for quasiholonomy, a concept introduced elsewhere and recalled here. The third robot, Quasimoro, has ...