If an item has holes or is too small, the level of suction may be insufficient to hold the item safely aloft. Scientists at the Automatic Manipulation Section of the Division of Mechatronics of the NETME Centre at Faculty of Mechanical Engineering BUT have found a solution to this problem – a suction gripper which can change the position of its suckers.

Suction end effectors are often used for transferring flat items. They grab an item using one or more suckers using a vacuum and transfer it to the required position. Problems here may occur when the suction end effector is used in a line where holes are made or other material taken off during the technological process. At the beginning of the process the item is solid, and so it can be easily gripped using suckers. But, by drilling holes or removing material in some other way, the surface of the item is changed. Thus it may happen that the surface area of at least one sucker does not connect fully with the item’s surface. The sucker then becomes non-functional and the holding capacity of the remaining suckers of the suction end effector may not be sufficient to transfer the item. The same problem occurs when the total holding capacity would otherwise be sufficient, but functional suckers are distributed too unevenly.

Scientists from the Faculty of Mechanical Engineering of the Brno University of Technology have worked on resolving the issue and developed an adaptive intelligent end effector which enables automatic adjustment of the suckers’ positioning according to the shape of the item being transferred. The new end effector is shown in Figure No. 1.

Fig. 1: Smart end effector for flat parts

The end effector is connected to the manipulator using a cone (1) for automatic exchange with a connector for transmitting electronic signals and a connector for transmitting pneumatic energy. To the cone is connected six suckers (2) on three grippers. The suckers can be moved using four step motors (3). The structure of the end effector also contains a reference switch (4) and control electronics (5).

When the end effector connects to the robot, the effector control electronics report via a specific code for verification of accuracy. The control system sends information about the required sucker position. The control electronics of the end effector at first ensure a move to the reference sensors before setting the suckers in the required position. Examples of sucker configurations for variously shaped flat items are shown in Figure 2.

Fig. 2: Examples of sucker configurations for some shapes of handled items

The intelligent suction robotic gripper is protected by the IPO CZ as a utility model with the title: “Adaptive Suction End Effector” No. 25083.