Robotic grippers
With Actuation Mode Switching

A Joint-Selective Robotic Gripper
with Actuation Mode Switching

Concept Design System Requirements

High Payload Capacity –Grasping things of a weight comparable to a beer case. Grasping Force of 100N.

Differentiated Grasping Behaviour –   Moderate dexterity. Fully actuated System with many DOF.

Compact Actuation Unit for end effector design. Minimum size and number of motors.


high accuracy and dexterity

High accuracy and dexterity with a very good grasping performance , high payload capacity of 70N, compact and lightweight actuation unit allows high relevance for industry applications and other mechanical robotic systems.

Concept design – technical requirements

State of the art.

High Payload Capacity = Large & heavy Actuators
Fully Actuated System with many DOF= High # Actuators (DOA)
Compactness + Light Weight

Roboy Project Requirements:

Tendon actuation
Actuation via electrical motors
3D printing and CAD-Modelling
Standard Components

Realization – finger design

Anatomical Purpose:

Grasping oriented functional design-maximization of the force of the hand

Strength to hold things up to 10 kg

An optimized range of movement (downscaling of the actual 20 DOF in the human hand ) for grasping

Different configurations of grasping (cylindrical, spherical, lateral) → realization of different ways of grasping 

Mechatronic Functionality:

Maximization of the “outcome force of the hand” (a distinction between intrinsic hand forces and hand-wrist force), while minimizing the number of actuators

The Concept –

Electromagnetic Joint Locking

Underactuated: # DOA < # DOF
DOA = 1Motor
Joint with electromagnetic Locking
Fully Actuated: # DOA = # DOF
DOA= 1Motor + Electromagnets

Testing phase

Hardware & Software

Testing Phase – Verification
Testing Phase – Verification

Embodiment Design


Differentiated Grasping Behavior for intermediate Forces

Grasp Taxonomie developed from Taxonomies by Feix u. a. (2016), Bullock u. a. (2013) and Katō (1987)

Test Results – Validation

FFP Index: Performance Test for Prehensile Tasks from (Sureshbabu, Metta, and Parmiggiani 2018)


cad files, documentations & presentations

More info

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