(Georgia Institute of Technology, 2004-02)
Love, Lonnie J.; Book, Wayne J.
Experimentation and a survey of the literature clearly show that contact stability in a force reflecting teleoperation system requires high levels of damping on the master robot. However, excessive damping increases the energy required by an operator for commanding motion. The objective of this paper is to describe a new force reflecting teleoperation methodology that reduces operator energy requirements without sacrificing stability. We begin by describing a new approach to modeling and identifying the remote environment bf the teleoperation system. We combine a conventional Multi-Input, Multi-Output Recursive Least Squares (MIMO-RLS) system identification, identifying in real-time the remote environment impedance, with a discretized representation 'of the remote environment. This methodology generates a time-varying, position dependent representation of the remote environment dynamics. Next, we adapt the target impedance of the master robot with respect to the dynamic model of the remote environment. The environment estimation and impedance adaptation are execute simultaneously and in real time. We demonstrate, through experimentation, that this approach significantly reduces the energy required by an operator to execute remote tasks while simultaneously providing sufficient damping to ensure contact stability.
(Georgia Institute of Technology, 2003-06)
Munir, Saghir; Book, Wayne J.
This article focuses on Internet-based real time control, such as remote bilateral teleoperation. In such applications it is required that the control loop be closed around a time delayed network. Although various researchers have worked on this problem, this paper focuses on two control strategies (based on wave variables and a time forward observer), bandwidth issues, and some related programming details. Experimental results of bilateral teleoperation via the Ethernet between Atlanta and Tokyo are given. The system used was a two degree of freedom haptic interface, bilaterally coupled to simulation (implemented on a windows NT based computer) of a similar system.
(Georgia Institute of Technology, 2000-10)
Watson, Cody; Book, Wayne J.
By converting from frequency domain models to time domain models, nonlinear behavior and linear distributed behavior can both be effectively represented. Three methods are presented to convert fluid line models from the frequency domain to the time domain. Comparison shows that combining components in the frequency domain has advantages in accuracy and efficiency in many practical cases. Methods of finding model poles and residues and ways to avoid numerical difficulties with poles at the origin are discussed.