A New Predictive Approach for Bilateral Teleoperation With Applications to Drive-by-Wire Systems

In this paper, a new predictive approach is proposed for the impedance control of bilateral drive-by-wire teleoperation systems. The proposed control structure includes two mirror predictors/observers in both the master and slave sides. These predictors/observers are used to simultaneously estimate the master and slave internal dynamics, and thereby to avoid the use of the delayed transmitted information. As a consequence, the influence of the delay on the whole system can be minimized and the performance can be improved. Under a set of suited hypotheses, the proposed control structure is shown to be uniformly ultimate stable, even in the presence of time-varying delays. Simulation results are presented to show the effectiveness of the proposed approach. The behavior of the control structure is also experimentally demonstrated while performing remote steering of a small autonomous vehicle

I. Introduction

During the last several decades, many different teleoperation systems have been developed to allow human operators to execute tasks in remote or hazardous environments. They are widely applied in different circumstances such as in outer space, undersea, nuclear plants, surgical operations, vehicle steering, etc. However, a time delay incurs in a long-distance transmission of information. In the case of bilateral teleoperation,¹

Signals from the master and the slave systems are reciprocally transmitted in both directions.

signals (i.e., environment contact torques or forces) of the slave system are reflected back to the master side operator, providing him with a feel of what is remotely sensed. Similarly, operation commands are sent to the slave system in order to execute the desired operation. According to the used signal transmission mechanism, the delay incurring during such an operation can be of different natures. For instance, transmission delay may be constant, time-varying (slow or fast), small, or large.