Bilal Ur Rehman was born in Faisalabad, Pakistan. He earned a Bachelor's degree in Electronics Engineering at the Comsats Institute of Information and Technology Pakistan in 2009. He acquired a Master’s in Robotics and Control at Umea University, Sweden.
During his master studies, he worked with development of simulation model and parameter identification techniques for electro-hydraulically actuated manipulators and System Identification techniques to derive data-driven models for the mineral froth flotation process.
Since the beginning of 2013 he is a member of the Advance Robotics Department at the Istituto Italiano di Tecnologia (IIT). He started his PhD research project to "Design and control of a dual arm system for the HyQ robot" under the supervision of Claudio Semini and Darwin Caldwell.
Deisgn and Control of a Dual Arm system for a Quadruped Robot (2013-present).
1. The Hydraulically Actuated Arm:
The Hydraullically actuated arm is designed, build and controlled by Bilal Ur Rehman as his on going PhD work. The designed arm is a compact and light-weight hydraulic robotic arm that is full torque controlled and without an external control unit. Perfectly suitable to be mounted on quadruped robots which are meant to perform sophisticated dynamic tasks. The designed arm is equipped with position encoder, torque and force sensors to achieve torque control. The video presents preliminary experimental results, demonstrating torque controlled capability to change joint impedance and user and robot interaction while performing a continuous motion with different speeds.
The following table lists the key specifications of the robotic arm.
|Arm extension||0.743m||Shoulder Adduction/Abduction (SAA)||-3.14/0.52 [rad]||126[Nm]|
|Weight||12.5kg||Shoulder Flexion/Extension (SFE)||-0.74/0.83 [rad]||120[Nm]|
|Maximum payload (fully extended)||10kg||Humerus Rotation (HR)||-1.57/0.068 [rad]||120[Nm]|
|Actuation system||Hydraulics||Elbow Flexion /Extension (EFE)||0/2.21 [rad]||225[Nm]|
|Control mode||Torque controlled||Wrist Rotation (WR)||-2.01/1.57 [rad]||60[Nm]|
|Degree of freedom||6Dof (3+1+2)||Wrist Flexion/Extension (WFE)||-1.57/0.52 [rad]||100[Nm]|
The HyQ-Centaur is part of privately funded European project called “AGILITY” with IIT, ETH and MPI
Legged robots with arms can potentially replace humans in dangerous and dirty tasks, where vehicles with wheels and tracks cannot go. Possible application domains are; disaster recovery (such as cleaning-up the Fukushima nuclear power plant), search and rescue, forestry and construction. Traditionally quadrupeds have been limited to load carrying or observation tasks as they have no manipulation ability. To remove this limitation, arms can be added to the body of the robot, enabling manipulation and providing assistance to the robot during body stabilization. The arm system will add a new dexterous manipulation capability to the already wide range of abilities of the HyQ, e.g., trotting, running, jumping, stabilization, external disturbance rejection, quick reflex action, and careful foot hold planning during navigation through unstructured terrain. This enables HyQ to perform new tasks, including: removing obstacles, grasping and manipulating objects, opening doors, or assisting the robot's balance (see Fig. 1 and 2).
Figure 1: Conceptual tasks performed by the centaur robot: (left) opening a door (right) carrying an object.
Figure 2: Conceptual tasks performed by the centaur robot: (left) passing through a narrow passage, (right) stabilization of the robot body.
B. Ur. Rehman, M. Focchi, M. Frigerio, J. Goldsmith, D. G. Caldwell, C. Semini, "Design of a Hydraulically Actuated Arm for a Quadruped Robot", Proceedings of the International Conference on Climbing and Walking Robots (CLAWAR), 2015
C. Semini, J. Goldsmith, B. Ur Rehman, M. Frigerio, V. Barasuol, M. Focchi, D. G. Caldwell, Design overview of the hydraulic quadruped robots HyQ2Max and HyQ2Centaur, The Fourteenth Scandinavian International Conference on Fluid Power (SICFP), 2015
P. La Hera, B. Ur Rehman, D. Ort ́ız, “Electro-hydraulically actuated forestry manipulator: Modeling and Identification,” in Proceedings of the International Conference on Intelligent Robots and Systems Celebrating 25 Years of IROS, Vilamoura, Algarve Portugal, October 7th -12th , 2012.
P. La Hera, B. Ur Rehman, A. Sanderg, “Modeling an industrial flotation process: A case study at the mining company Boliden AB,”in Proceedings of World Automation Congress - ISIAC 2012 - 9th International Symposium on Intelligent Automation and Control, Puerto Vallarta, Mexico, June 24th-28th 2012.