Hand-in-glove human-machine interface and interactive control: task process modeling using dual Petri nets

Abstract

An approach to interactive control of human-robot systems using dual Petri nets is presented. A human and robot(s) work side by side by sharing the task goal and part of the process state. The human is instrumented with a type of data glove so that the robot can monitor the human state and coordinate its action with the human. First, the class of interactive tasks performed by a human and robot is described as a dual-agent, concurrent, event-driven system, and represented by two Petri nets interacting to each other. One Petri net represents the human side task process, while the other represents the robot side. Both sides proceed with their assigned tasks concurrently through state transitions within each Petri net. They observe the partner's state and coordinate each step of task performance as specified by the conditional state transition involved in the Petri nets. A distributed control system is directly derived from the dual Petri net representation. As an exemplary case study, a cable connection task is considered. The task is first decomposed into two subtasks, which are assigned to the human and the robot. A data glove worn by the human is developed for measuring the hand location as well as the force and position of each finger tip. A decentralized controller is built and a proof-of-concept experiment is described.