As the technology of industrial automation using robot system grows the rapid advance, productivity improvement and decrease in number of maintenance, management occur in many fields. Therefore, more various and intelligent robot motions are needed without human being help. Considering this situation, the need of robot with various, fast and safe acting sensors are demanded. In these sensings, the slippage sensing gives us specific information between ripper and object while grasps the object. In this paper, we proposed new slippage sensing algorithm for various and intelligent robot motion. So, optimal grasping force control and compensation of position error is possible for an adaptive task execution using adaptive control.