Determination of Gripping Forces for Handling Surface-sensitive Objects

Even for modern robot attached gripping solutions, surface-sensitive object handling remains a challenge. A minimal gripping force is required to grip and handle a surface-sensitive object safely. At the same time, this gripping force should not exceed a certain level to avoid damaging the sensitive surface of the object. Because of this, it is necessary to determine the mostly small range of optimal gripping forces to ensure a safe handling. Therefore, this paper describes an approach to evaluate this range of gripping forces for surface-sensitive objects using by means of chocolate covered marshmallows. For this purpose, a test bench with the same characteristics as a planned gripper is developed. Throughout the project, this planned gripper will be controlled with the help of the detected range of gripping forces. In addition to these static measurements, it is planned, that the gripper will calculate the handling speeds, accomplished by a six-axis industrial robot, with its acceleration forces. The achieved results of this paper will be the starting point for the upcoming measurements with the robot. Furthermore, the influence of the temperature on the range of gripping forces was evaluated, to show the relevance of consistent environmental conditions for the handling of surface-sensitive objects.