This paper presents a modular control architecture that enables a mobile manipulator to compliantly perform manipulation tasks in partially-known everyday human environments. An impedance velocity/force controller that allows the execution of a great variety of tasks under the Task Frame Formalism (TFF) is implemented. Tasks are represented as a net of basic abilities which are performed by the...

Force control of parallel robots with rotational degrees of freedom through impedance algorithms is considerably influenced by the representation method of the end-effector orientation. Using the natural invariants of the rotation matrix and the angular velocity vector in the impedance control law has some theoretical advantages, which derive from the Euclidean-geometric meaning of these entiti...

This article presents the results of two in-vivo studies providing measurements of human static ankle mechanical impedance. Accurate measurements of ankle impedance when muscles were voluntarily activated were obtained using a therapeutic robot, Anklebot, and an electromyographic recording system. Important features of ankle impedance, and their variation with muscle activity, are discussed, in...

Manipulator compliance is well known to be important to robot manipulation and assembly. Recently, this has been highlighted by the development of new higly-compliant robot manipulators such as the Barrett arm or the DLR lightweight manipulator [1], [2]. It is also clear that dexterous manipulation involves touching the environment at different locations simultaneously (perhaps at different poi...

OBJECTIVE To investigate the effectiveness of an upper limb rehabilitation robot therapy on hemispatial neglect in stroke patients. METHODS Patients were randomly divided into an upper limb rehabilitation robot treatment group (robot group) and a control group. The patients in the robot group received left upper limb training using an upper limb rehabilitation robot. The patients sat on the r...

In this paper we present a method of whole-body manipulation of large objects by a humanoid robot using a pivoting motion. Pivoting manipulation can be an alternative to pushing or lifting for more dexterous and stable operation, which is often used by humans to move large and bulky furniture. This paper describes a method and control techniques for a humanoid robot to perform the manipulation ...

A human performs a variety of skillful movements by adjusting dynamic characteristics of his or her musculoskeletal system according to a task involved. Such characteristics of human movements can be described by mechanical impedance parameters. If the regulation mechanism of human impedance properties during the task can be clarified and modeled, there is a possibility that human skillful stra...

The paper presents a new torque-controlled lightweight robot for medical procedures developed at the Institute of Robotics and Mechatronics of the German Aerospace Center. Based on the experiences in lightweight robotics and anthropomorphic robotic hands, a small robot arm with 7 axis and torque-controlled joints tailored to surgical procedures has been designed. With an optimized anthropomorph...

In this paper, the issue of control of impact forces generated during the interaction between the hopping robot toe and the ground during landing has been considered. The force thus generated can damage the robot altogether. With the objective to control these impact forces impedance control strategy has been applied to the hopping robot system. The dynamics pertaining to the impact between rob...

In impedance control for contact force tracking, it is well known that the reference trajectory of the robot is calculated from known environment stiiness 1]. Here we present a simple technique for determining the reference trajectory under the condition that the environment stiiness is unknown. The technique is developed based on the replacement of the unknown stiiness with a function of the m...