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LabsHumanoids & Human Centred MechatronicsProjects ■ Variable Impedance Robotic Arm

CompAct™ Arm


Compact Arm
Fig. 1 – The CompAct arm.

Compliance is a fundamental requisite for any robot that needs to perform human-machine interaction or more generally to directly interact with the external world. This is because the physical elasticity of the drives’ transmission system makes the robot to be able to automatically adapt itself to the environment it is interacting with still keeping the force exchange low, which is something that cannot be achieved with traditional heavy and stiff industrial manipulators.

Although compliance can effectively make the difference, from the engineering point of view it introduces also some side effects. It typically induces underdamped dynamics which deteriorate the stability margin and the accuracy of the robot (due to the induced oscillations and static deflections) and limits the bandwidth which can be set in the controlled system. These drawbacks are tackled in mammalians, which exhibit joint compliance, by the synergetic presence in their body of both compliance and physical damping. The properties of passive compliance and damping typical of biological joints explain why e.g. humans are able to safely interact and be robust during collision due to compliance while at the same time having the potential of achieving fast, smooth yet accurate motion thanks to physical damping.

The mentioned benefits introduced by damping motivated the design and development of the CompAct™ Arm, Fig. 1, i.e. a manipulator powered by actuators with intrinsic rich skills related to the synergetic combination of passive compliance and variable physical damping. To the authors knowledge this is the first robotic systems to exhibit these combined properties. We believe that such a system is step towards the achievement of functional performance of natural systems and particularly the human in terms of motion agility, safety, without compromising dynamic performance (motion speed), precision and smoothness.

Tech transfer / Entrepreneurial initiatives

Along with R&D activities, we are currently actively involved in tech transfer to turn this technology into a product. We are now doing fundraising and looking forward to enlarge the team accordingly with a business plan that the team developed. For any further info, contact Matteo Laffranchi

Related pages

CompAct™ SEA
CompAct™ Actuators with Variable Physical Damping



Last Updated on Tuesday, 24 September 2013 16:11


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