parameter identification techniques are particularly attractive to determine the inertial parameters of robot manipulators and manipulated payloads. these parameters are particularly needed in implementation of a model-based controller for robot manipulators. in this paper, the inertial parameters of a manipulated rigid-body object have been estimated. the newton-euler equations will be employe...

This paper deals with impedance control of a rotary Series Elastic Actuator designed to assist in flexion/extension of the knee joint during physical therapy. The device includes a DC motor, a worm gear and a customized torsion spring. Since the elastic element is the most important component in the actuator design, a finite element analysis is used to meet the specific requirements of knee ass...

The primary issue in defining an integration architecture is the ability to separate the concerns of each application component, while simultaneously creating an integrated system. This separation has several dimensions. Without this ability to separate the concerns, the resulting system will not only be tightly coupled and resist change and enhancement, but failures in one portion of the syste...

Policy-based management provides a means for IT systems to operate according to business needs. Unfortunately, there is often an “impedance mismatch” between the policies administrators want and the controls they are given. Consider the Apache web server. Administrators want to control CPU and memory utilizations, but this must be done indirectly by manipulating tuning parameters such as MaxCli...

The paper compares various approaches to implementing a compliant Cartesian behavior for robotic manipulators: impedance, admittance and stiffness control. A new controller structure is proposed, which consists of an impedance controller enhanced by local stiffness control. This structure consistently takes into account the two time scale property of the joint and Cartesian control loops. The D...

For complex robotic tasks (manipulation, locomotion, haptics, ...), the lack of knowledge of precise interaction models, the difficulties to precisely measure the task associated physical quantities (force, speed, ...) in real time and the non-collocation of sensors and transducers have negative effects on performance and stability of robots when using simple force or simple movement controller...

Creating a compelling haptic sense of immersion in a virtual environment is a challenging task for the control engineer. A haptic display must render both low impedance free-space motion and high impedance rigid constraints while ensuring stable interaction. This paper outlines a control design approach for the most common haptic display implementation, the impedance display. Two-port absolute ...

In this paper, the contact motion between rigid body systems floating in space is formulated and dynamic conditions are investigated in order to capture a non-cooperative satellite. As for the theoretical investigation, impedance matching is discussed for the case in which the robot hand under impedance control approaches and collides with a passive target, and a specific impedance value is def...

This paper reveals the essential equivalence of second order impedance control and proportional gain explicit force control with feedforward. This is rst done analytically by reviewing each control method and showing how they mathematically correspond. For stii environments the correspondence is exact. However, even for softer environments similar response of the system is indicated. Next, the ...

The problem to ensure safety of performant robot arms during task execution was previously investigated by authors in [1], [2]. The problem can be approached by studying an optimal control policy, the “Safe Brachistocrone”, whose solutions are joint impedance trajectories coordinated with desired joint velocities. Transmission stiffness is chosen so as to achieve minimum–time task execution for...