An object grasp motion model using control signal and cylinder pressure in demolition machines for disaster response work

The purpose of this paper is to model and identify an object grasp motion, which is a requisite condition to make a demolition machine grasp an object. Grasping an object is a highly difficult task that requires safe and precise operations, so identifying a grasp or non-grasp is necessary for providing operational support, particularly in disaster response work. These types of outdoor machines lack visual and tactile sensors, so practically available lever operation and cylinder pressure sensors are adopted. The grasp motion is modeled by using sequential transitions of the on-off state of the control signal and cylinder pressure data for the grapple and the manipulator. The results of experiments conducted to transport objects using an instrumented hydraulic arm indicated that the modeled grasp motion effectively identifies a grasp or non-grasp with high accuracy, independently of operators and environments.