Much work has also been done in controlling the remote
robots with delays using bilateral control [6]–[8], including
both the contact force and position (velocity) of the robot. In
bilateral control, force is the input and velocity is the output in
the teleoperator side, whereas velocity is the input and force
is the output for the robot. There have been some new ideas
presented so far in controlling such kind of systems. In [6],
passivity and scattering theory were used to analyze system
stability and derive a compensation scheme for constant time
delay. Mitra and Niemeyer [7] further extended this result via
introducing wave variables to define a new configuration for
force-reflecting teleoperators