Time-delays are important components of many dynamical systems that describe coupling or interconnection between dynamics, propagation or transport phenomena, and heredity and competition in population dynamics. The stabilization with time delay in observation or control represents difficult mathematical challenges in the control of distributed parameter systems. It is well-known that the stabi...

Hierarchical inverse dynamics based on cascades of quadratic programs have been proposed for the control of legged robots. They have important benefits but to the best of our knowledge have never been implemented on a torque controlled humanoid where model inaccuracies, sensor noise and real-time computation requirements can be problematic. Using a reformulation of existing algorithms, we propo...

The Jacobian matrix of a robot manipulator is central to the analysis, kinematics, dynamics, and control of robot manipulators. In many instances, the Jacobian and its inverse or pseudo-inverse are needed and utilized in the control equations of robot manipulators. In robotics, translations and rotations, transforms whose variables of motion, distance for translations, angles for rotations, com...

This paper describes a three-dimensional parallel solution scheme for inverse dynamics of link mechanisms, which has already been proposed for the two-dimensional case and applied in several inplane motions. In this theory, the entire system is subdivided into finite elements and evaluated as a continuum. A single-link structure of a pin joint and a rigid bar is expressed using the Shifted Inte...

Linearized dynamics models for manipulators are useful in robot analysis, motion planning, and control applications. In this paper we use techniques from the spatial operator algebra to obtain closed form operator expressions for two types of linearized dynamics models, the Linearized Inverse and Forward Dynamics Models. We rst develop spatially recursive algorithms of O(n) and O(n) complexity ...

The paper presents the semi-active vibration control based on the Skyhook algorithm which benefits from the adaptively tuned inverse magnetorheological (MR) damper model. The structure of the inverse model consists of the atan function and a linear viscous damping component. The proposed algorithm was tested by simulation of the quarter-car suspension model subjected to multiple bump road excit...

− In this paper, we describe a parallel solution scheme for inverse dynamics, and its application to feed-forward control of link mechanisms under various boundary conditions. The conditions include such cases as openand closed-loops, and even one that continuously changes its form from an opento a closed-loop. The dynamic equations conducted by generally used schemes such as the Newton-Euler m...

This study compared adaptation in novel force fields where trajectories were initially either stable or unstable to elucidate the processes of learning novel skills and adapting to new environments. Subjects learned to move in a null force field (NF), which was unexpectedly changed either to a velocity-dependent force field (VF), which resulted in perturbed but stable hand trajectories, or a po...

In addition to well-thought mechanical designs, there is a need for advanced control algorithms that can provide the versatility needed to locomote on difficult, potentially extreme terrains. Such a controller should offer two important features: high tracking performance to guarantee precise feet and hand placements when needed and control of contact forces created by the robot on its environm...