Both of our Adaptive Grippers are able to grip objects of various shapes using their innovative finger mechanism. This allows for firm grips of various objects without the need to build custom grippers for each application. In addition to this adaptability, the Gripper is able to determine when it has gripped an object. This is useful to determine if the pick-up procedure was performed correctly and if the robot can move to the next step of its program. In some cases, however, it is also useful to verify if the Gripper still has the object after a motion is executed by the robot. For example, if the object position was not initially determined accurately (for instance, if the object has moved or if the vision system had a problem), it is possible that the object could be picked up in an awkward position. In this situation, the object might slip out of the Gripper if the robot moves very rapidly to its next position. Knowing that the object was dropped is crucial for many applications. So below, I will explain the appropriate procedure to verify if the Adaptive Gripper still has the object after a robot motion.

How the object is detected during the grip

When a command is sent to close the fingers of the Gripper, the motor moves towards a target position. If the motion is stopped because the Gripper has found an object, the force applied by the fingers will increase until the current sent to the motor exceeds its limit (which is fixed using the force parameter). At that moment, the motor will stop moving and the grip force will be maintained by the Gripper's auto-locking mechanism. By reading the motor position, the Gripper is able to determine if an object was gripped or if the motion was stopped due to the fingers touching themselves. However, from that moment, the Gripper will consider that the object is gripped and will not detect an object loss unless the procedure explained in the next section is executed.