The Hand CLASH (Compliant Low-cost Antagonistic Servo Hand) was designed during the EU Project Soma to grasp safely and reliably fruits and vegetables. It is a compliant, yet low-cost hand.
Technical data
System description
A main feature of this hand is that it can adapt the compliance of the fingers passively by changing the pretension of the tendons. Furthermore the compliance can be actively controlled similar to the DLR Hand II. For example if the hand grasps a mango, in the contact phase of the grasp the hand is very soft to reduce the contact forces and increase the area of contact. In the lift phase the hand increases the stiffness to get a stable grasp. This mechanism is inspired by humans hands, where contraction of the muscle leads to an increased hand stiffness.
The hand was developed especially for grasping fruits and vegetables, as can be seen here on a lime. The Use Case is the online supermarket, where robots will be able to do these jobs in the future.
Credit: DLR (CC-BY3.0).
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A major focus of the EU project SOMA was to use the environment as a tool to grasp objects better. The CLASH wrist now allows the wall grip to be carried out in the box without restricting the range of movement of the robotrarm.
The two degree of freedom wrist allowed to grasp objects out of a shelf. The object can also be behind another object, because the wrist increases the workspace of the robot arm.
Credit: DLR (CC BY-NC-ND 3.0).
The hand can be used on a robot, but also in hand in hand experiments, whre humans carry the hand. For this a battery and a force feedback handle can be mounted.
Credit: DLR CC-BY 3.0.
The hand can also grasp solid objects like cans and other industrial products.
In the future the hand should be benchmarked by the YCB benchmark.