1. Introduction Palletizing robot i

1. Introduction Palletizing robot is the key equipment of automatic logistics system for cigarette products in tobacco industry. As an important part of palletizing robot, the clamp device, its execution ability, reliable performance, shape size and so on have important influence on the whole palletizing of cigarette packing cases [1-2]. The palletizing robot works by means of clamp device adsorbing the surface of cigarette packing case. Due to transportation, storage and other reasons, the surface of the case is uneven, there are dust impurities and other problems[3–5], its compressive strength and surface flatness are reduced, cases is not adsorbed firm and fall down. So the cigarette and case are damaged, causing certain economic loss. In addition, dealing with falling and broken cigarette packing case leads to increased labor intensity and reduced productivity. Therefore, in order to complete the efficient and high quality cigarette packing case recycling, reduce their drop number, and improve the production efficiency, the robot's clamp device has been proposed for higher adaptability [6]. In recent years, there have been many researches and improvements on robot's clamp device. Su Yazhong [7] had improved the negative pressure pipeline, suction cup and negative pressure solenoid valve in the absorbing device of the case. Ma Liang [8] et al. used planar sponge suction cup, set up a special palletizing procedure, adjusted precisely the position of the clamp device to catch the case,