# Topics > Projects >  Handheld Robotics, Computer Science Department, University of Bristol, Bristol, England, United Kingdom

## Airicist

Website - handheldrobotics.org

Team:

Austin Gregg-Smith

Walterio Mayol-Cuevas

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## Airicist

The Design and Evaluation of a Cooperative Handheld Robot

Published on May 15, 2015




> Abstract—This paper concerns itself with a relatively unexplored type of personal robot that operates in the tool space. Handheld robots aim to cooperate with the user to solve tasks and improve what tools can offer enhanced by actuation, sensing, and importantly, task knowledge. To this
> end, we devised a new lightweight robotic platform that has 4
> DoF and uses a cable driven continuum structure. Feedback
> from the robot to the user is provided in an intuitive, implicit
> manner by the robot end effector pointing towards the goal,
> avoiding pointing, and/or refusing to perform an action when
> it conflicts with the task specification. We evaluate two generic
> tasks involving aiming in space and picking/placing objects with
> a number of volunteers. Repeated measures ANOVA is used to
> ...

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## Airicist

Article "Bristol Researchers Create Handheld 3D Printed Robots That Assist & Correct Users"

by Bridget Butler Millsaps
May 27, 2015

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## Airicist

Inverse Kinematics and Design of a Novel 6-DoF Handheld Robot Arm

Published on May 17, 2016




> We present a novel 6-DoF cable driven manipulator for handheld robotic tasks. Based on a coupled tendon approach, the arm is optimized to maximize movement speed and configuration space
> while reducing the total mass of the arm. We propose a space carving approach to design optimal link geometry maximizing structural strength and joint limits while minimizing link mass. The design improves on similar non-handheld tendon-driven manipulators and reduces the required number of actuators to one per DoF. As the manipulator has one redundant joint, we present a 5-DoF inverse kinematics solution for the end effector pose. The inverse kinematics is solved by splitting the 6-DoF problem into two coupled 3-DoF problems and merging their results. A method
> for gracefully degrading the output of the inverse kinematics is described for cases where the desired end effector pose is outside the configuration space. This is useful for settings where the user is in the control loop and can help the robot to get closer to the desired location. The design of the handheld robot is offered as open source. While our results and tools are aimed at handheld robotics, the design and approach is useful to non-handheld applications.
> 
> From the paper:
> 
> Austin Gregg-Smith and Walterio Mayol-Cuevas, Inverse Kinematics and Design of a Novel 6-DoF Handheld Robot Arm. IEEE International Conference on Robotics and Automation (ICRA), 2016.

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