Hideyuki Murayama

Human-robot collaboration in precise positioning of a three-dimensional object

This paper deals with fundamental issues of human-robot cooperation in precise positioning of a flat object on a target. Based on the analysis of human-human interaction, two cooperation schemes are introduced. Several algorithms implementing these schemes are developed. A general theoretical framework for human/robot cooperation has been developed to represent these algorithms. The evaluation of the algorithms was carried out using our in-house made robot prototype and experiments by human subjects has demonstrated the effectiveness of our schemes. The main problem was the regulation of the robot-human interaction. Since the robot has no range sensors, it has to rely on the force and displacement information resulting from the interaction with human to understand human intention. The way the robot interprets these signal is crucial for smooth interaction. To be able to carry out a concrete task a simplification was made, in which robot and human do not directly hold the object but a frame to which the object and various sensors are attached.

Human-Robot Cooperation in Precise Positioning of a Flat Object

Abstract This paper deals with fundamental issues of human-robot cooperation in precise positioning of a flat object on a target. Based on the analysis of human-human interaction, two cooperation schemes are defined. An algorithm imitating one of these schemes is presented. A general mathematical framework for human/robot cooperation has been developed, based on which several algorithms are proposed. The evaluation of the algorithms was carried out using our in-house made robot prototype using a number of subjects has demonstrated the effectiveness of our ideas. The main problem was the regulation of the robot human interaction. Since the robot has no range sensors, it has to rely on the force and displacement information resulting from the interaction with human. The way the robot interprets these signal is crucial for smooth interaction. To be able to carry out a concrete task a simplification was made, in which robot and human do not directly hold the object but a frame to which the object and various sensors are attached. Based on our research results, we succeeded in installing a commercial platform.

Scissor lift with real-time self-adjustment ability based on variable gravity compensation mechanism

Most robots involved in vertical movement against gravitation require actuators large enough to support their own weight. To improve the inherent safety of such robots against the large actuators and reduce their energy consumption, numerous gravity compensation mechanisms (GCMs) have been proposed. Our previous study proposed a variable GCM (VGCM) that uses two types of springs and can adjust the compensation force. In this paper, a VGCM-based scissor lift (pantograph lift) that uses three springs and a smaller actuator is proposed. A prototype is designed and fabricated, and the performance of the prototype is evaluated experimentally. The results demonstrate that the developed scissor lift meets the design specifications. In addition, a load estimator is established based on the dynamic model of the scissor lift. A real-time self-adjustment method that automatically changes the compensation force is proposed, and its effectiveness is verified. Graphical Abstract