The application of the human-robot cooperative system for construction robot manipulating and installing heavy materials

From the recent trends in the demand for buildings, the customers increasingly prefer high-rise buildings. This reinforces the fact the general contractors focus on the cut-down of costs to reduce the term of works in construction. As this effort, the ASCI (automation system for curtain-wall installation) which combined with a multi-D.O.F. manipulator to a mini-excavator was developed and applied on construction site. But, it is found that the operation by one operator with more intuitive operation is required to improve the performance of operating the ASCI which needs one person with a remote joystick and the other operating an excavator. To overcome the difficulties in operating the existing automated system from the viewpoint of construction efficiency, the human-robot cooperative (HRC) system is proposed to cope with various and untypical constructing environment through the real-time interacting with a human, robot, and constructing environment simultaneously. The physical power of a robot system helps a human to handle heavy materials with relatively scaled-down load. Also, a human can feel and response the force reflected from robot end-effector acting with working environment. To realize the proposed system, the human-robot relation is modeled with target dynamic system which describes physical behaviors with impedances. The HRC system is featured by the power-assistance and force-reflection. The effect of force-reflection is realized by the feedback of force reflected from an external force-sensor. The robot-environment relation is modeled by the compliancy of impedance control. The position-tracking performance in unconstrained condition is improved by the impedance controller including position control. This study presents the experiments and evaluations to verify the proposed human-robot cooperative system for robotic applications in construction giving the performance tests, such as force assistance, force reflection, and position-tracking in two axes - - manipulator