Comparison of Collaboration Methods between Users in Remote Robot Systems with Force Feedback

In this paper, we deal with cooperative work between two remote robot systems with force feedback and make a comparison of collaboration methods between two users by experiment. In the cooperative work, a user of each system operates a robot arm having a force sensor to carry an object together with the other user by using a haptic interface device. For collaboration between the users, the reaction force is calculated from position information of the haptic interface devices and presented to each user to transmit the force information to the other user. Then, the user can feel the force which is sensed by the force sensor as well as the calculated reaction force. We change the ratio of the two kinds of force presented to each user as collaboration methods in the following two relationships between the users: Equal and master-slave relationships. Experimental results demonstrate that the preferable ratios are dependent on the type of relationship.

I. Introduction

By using remote robot systems with force feedback, we can conduct various types of cooperative work [1]–[6]. This is because a user of the system can feel the shape, softness, surface smoothness, and weight of a remote object touched/hit by a robot arm having a force sensor by using a haptic interface device while watching video. Therefore, we can expect to improve the efficiency and accuracy of the cooperative work largely. However, when force information is transmitted over a network such as the Internet, which does not guarantee the quality of service (QoS), the quality of experience (QoE) may seriously be degraded and the system may become unstable owing to the network delay, delay jitter, and packet loss. To solve the problems, we need to exert QoS control [3] and stabilization control [4] together.