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Labs ■ Dynamic Legged Systems

Hydraulically Actuated Quadruped - HyQ


*** Check out the open positions for masters/internships here at the Dynamic Legged Systems Lab (November 2013) ***

 

hyq robot 2011 front  HyQ and HyQ blue  

left: HyQ robot in kneeling position; right: HyQ with HyQ-blue that has been sold to the Agile & Dexterous Robotics Lab of ETH Zurich in July 2013.

HyQ is a fully torque-controlled Hydraulically actuated Quadruped robot (pronounced [hai-kju:]) developed in the Department of Advanced Robotics at the IIT. HyQ is designed to move over rough terrain and perform highly dynamic tasks such as jumping and running with different gaits (up to 3-4m/s). To achieve the required high joint speeds and torques, hydraulic actuators are powering the robot’s 12 active joints. For more information on the robot scroll down or refer to (Semini, dissertation, 2010).

Goals of the project are the design of versatile robots, the investigation of various aspects of quadrupedal locomotion, adjustable compliance, energy efficiency, compact hydraulic actuation and onboard power systems.

Capabilities

  • Walk, trot and run up to 2m/s (video at 0:40)
  • Rear and jump up to 0.5m from squat (video at 1:05)
  • Balance under unstable ground even under disturbance (video at around 1:05)
  • Animal-like step reflex (video)
  • Torque and position-controlled joints (video)
  • Indoor and outdoor operation
  • Real-time control system with dynamics simulator

 HyQ roughTerrain1 HyQ SquatJump HyQ lateralDisturbance 

 

System Overview

The following table lists the key specifications of the robot platform.

Dimensions (fully stretched legs) 1.0m x 0.5m x 0.98m (Length x Width x Height)
Weight 80kg (external hydraulic power supply), 100kg (onboard hydraulic power supply)
Number of active DOF 12 hydraulic actuators (8 cylinders in hip and knee flexion/extension joints and 4 rotary actuators in the hip abduction/adduction joint)
Actuator Types Hydraulic cylinders (80mm stroke, 16mm bore) and rotary hydraulic actuators
Joint range of motion 120°
Maximum torque (hydraulic cylinders) 181Nm (peak torque at 200bar pressure)
Maximum torque (rotary actuator) 120Nm (constant output torque at 200bar pressure)
Onboard sensors High-resolution relative+absolute position and torque sensors on each joint, inertial measurement unit (IMU), hydraulic system pressure, stereo camera, LIDAR
Onboard computer PC104 Pentium, real-time Linux (Xenomai) with multi-I/O boards
Control frequency 1 kHz for motor control, 250Hz for motion generation

Figure 2 shows the CAD model of the robot and 2 pictures with different views of HyQ’s mechanical skeleton built in aerospace-grade aluminium alloy and stainless steel. The robot’s torso is built with a folded aluminium alloy sheet with internal walls to achieve high torsional robustness.

alt alt alt

Figure 2: CAD model of HyQ with onboard hydraulic system (left) and pictures of the mechanical skeleton of HyQ (centre and right).

 

Leg Design

Each leg features three degrees of freedom (DOF), two in the hip (abduction/adduction and flexion/extension) and one in the knee (flexion/extension). The leg is built of a light-weight aerospace-grade aluminium alloy and stainless steel. High resolution encoders and load cells in each joint allow a smooth control of both position and torque. We are currently designing and testing several foot designs with and without adjustable stiffness to soften the impacts at foot touch-down and to store energy from one step to the next.

alt alt alt alt

Figure 3: Leg Design Evolution: CAD model and picture of HyQ leg prototype (left) and the improved final leg (right)

In the beginning of 2008, we successfully reached the first milestone of the project: The design and construction of a first 2-DOF leg prototype (Fig. 3, left) with an actuated hip and knee joint in the sagittal plane (Semini et al., 2008). Since then, we have extensively used the leg to test its mechanical structure, the hydraulic actuation system and to evaluate various joint level controllers (Semini et al, 2008; Cunha et al, 2009; Focchi et al, 2010). For the experiments the leg was either mounted to a vertical slider or fixed to a work bench. We studied the behavior of the mechanical structure and hydraulics upon leg impact with varying leg weights up to 25kg. Furthermore, we tested the leg during continuous hopping with different frequencies up to 3Hz, since hopping is a simplified form of running (see video).

The experiments proofed that hydraulic actuation is very suitable for highly dynamic legged robots, due to its high power-to-weight ratio, high torque and speed and ability to cope with torque peaks (Semini, 2010).

 

Future Applications

  • Search and rescue operations
  • Operations in contaminated and dangerous areas
  • Forestry, construction and firefighting application
  • Inspection and exploration tasks
  • Experimental platform for legged robotics research (e.g. legged locomotion, biomechanics, force control, autonomous navigation)

 

peopleInvolved People

ClaudioSemini

Claudio Semini (team leader)

MicheleFocchi

Michele Focchi (post-doc)

MarcoFrigerio

Marco Frigerio (post-doc)

Victor Barasuol (post-doc)

IoannisHavoutis

Ioannis Havoutis (post-doc)

StephaneBazeille

Stephane Bazeille (post-doc)

JesusOrtiz

Jesus Ortiz (post-doc)

BilalUrRehman

Bilal-Ur Rehman (PhD student)

HamidrezaSaghir

Hamidreza Saghir (PhD student)

HamzaKhan

Hamza Khan (PhD student)

Jake Goldsmith (technician - mechanics)

and Nikos Tsagarakis, Emanuele Guglielmino, Ferdinando Cannella, and Prof. Darwin Caldwell

Recent Master Students

AlexanderWinkler

Alexander Winkler

 

Francesco Rovida

 

Anis Meguenani

systemADVR Department technicians

Marco Migliorini, Stefano Cordasco, Phil Hudson, Carlo Tacchino (electronics)

Gianluca Pane and Giuseppe Sofia (mechanics)

Alessio Margan (software)

 

Alumni

Jonas Buchli was the team leader of the HyQ project from 8/2010 to 8/2012 and considerably contributed to the following areas of the project: torque control, impedance control, rigid body inverse dynamics control, locomotion control and planning, software etc. In September 2012 he founded the Agile & Dexterous Robotics Lab at the Swiss Federal Institute of Technology (ETH) in Zurich, Switzerland. In July 2013 we delivered a copy of HyQ, called HyQ-blue, to his lab in Zurich.

Thiago Boaventura did his MSc research in the HyQ group in 2009 and stayed in the group for his PhD that he successfully defended in April 2013 with the title "Hydraulic Compliance Control of the Quadruped Robot HyQ" (see publication list below). In June 2013 he joined the Agile & Dexterous Robotics Lab at the Swiss Federal Institute of Technology (ETH) in Zurich, Switzerland as a postdoctoral researcher.
 

groupCollaborating Groups

Agile & Dexterous Robotics Lab, Swiss Federal Institute of Technology (ETH)

Legged Robotics Group of Autonomous System Lab, Swiss Federal Institute of Technology (ETH)

Autonomous Motion Department of Max Planck Institute (MPI)

Departamento de Automação e Sistemas, Universidade Federal de Santa Catarina, Florianopolis, Brazil

Computational Learning and Motor Control Lab (CLMC lab), University of Southern California, USA

Centre for Power Transmission and Motion Control, University of Bath, UK

Department of Intelligent Hydraulics and Automation, Tampere University of Technology, Finland

Institute of Machine Design and Hydraulic Drives, Johannes Kepler University of Linz, Austria

 

In the news (only 2014)

IEEE spectrum blog of 14 March 2014: "HyQ Quadruped Robot Is Back With Even More Tricks"

The Gadget Show of UK channel 5 of 24th February 2014

Discovery Channel's Daily Planet of 6 January 2014

youtube Videos

HyQ Robot - Hopping Leg Prototype (2008)

HyQ - IIT's Hydraulic Quadruped Robot - Introduction (Sept. 2011)

Hydraulic Quadruped Robot HyQ - Leg Assembly (Oct. 2011)

High-performance hydraulic force control of HyQ robotic leg @ IIT (2012)

HyQ - Balancing and First Outdoor Tests (May 2012)

HyQ Robot Step Reflex (July 2013) 

Probably The Most Versatile Quadruped Robot (March 2014)
 

softwareSoftware

We use the SL simulator and motor controller package for our robot (you can find a technical report about it at this page)
At this page, you can also download a distribution of the code generator for kinematics and dynamics that we are developing as part of our research.

More information on the hydraulic torque control can be found here.

 

paperList of Publications

Dissertations

2013

  • T. Boaventura, "Hydraulic Compliance Control of the Quadruped Robot HyQ", PhD thesis, Istituto Italiano di Tecnologia and University of Genoa, Italy, 2013
        [full thesis]
  • M. Focchi, "Strategies To Improve the Impedance Control Performance of a Quadruped Robot", PhD thesis, Istituto Italiano di Tecnologia and University of Genoa, Italy, 2013
        [full thesis]
  • M. Frigerio, "Model–Based Code Generation for the Kinematics and the Dynamics of Articulated Robots", PhD thesis, Istituto Italiano di Tecnologia and University of Genoa, Italy, 2013
        [full thesis]

2010

  • C. Semini, "HyQ – Design and Development of a Hydraulically Actuated Quadruped Robot,” Dissertation, Istituto Italiano di Tecnologia and University of Genoa, Italy, 2010.
       [full thesis]
Journal, Conference Papers and Posters


2014

  • V. Barasuol, J. Buchli, V. J. De Negri, E. R. De Pieri, D. G. Caldwell, C. Semini. On Trajectory Generation and Active Impedance for Running Trotting. Dynamic Walking 2014.
  • S. Bazeille and M. Camurri and J. Ortiz and I. Havoutis, D. G. Caldwell, C. Semini, Terrain mapping with a pan and tilt stereo camera for locomotion on a quadruped robot. ICRA14 Workshop on Modeling, Estimation, Perception and Control of All Terrain Mobile Robots (WMEPC14).
  • S. Bazeille, V. Barasuol, M. Focchi, M. Frigerio, I. Havoutis, D. G. Caldwell, C. Semini, Quadruped Robot Trotting over Irregular Terrain Assisted by Stereo-Vision, Journal of Intelligent Service Robotics, Volume 7, Issue 2, pp 67-77, 2014.
  • A. Winkler, I. Havoutis, S. Bazeille, J. Ortiz, M. Focchi, R. Dillmann, D. G. Caldwell, C. Semini, "Path Planning with Force-Based Foothold Adaptation and Virtual Model Control for Torque Controlled Quadruped Robots," IEEE International Conference on Robotics and Automation (ICRA), 2014.
         [full article]
  • E. Kostamo, M. Focchi, E. Guglielmino, J. Kostamo, C. Semini, J. Buchli, M. Pietola, D. G. Caldwell, "A Magnetorheologically Damped Compliant Foot for a Legged Robotic Application," Journal of Mechanical Design, Vol. 136, 2014.


2013

  • C. Semini, V. Barasuol, T. Boaventura, M. Frigerio, J. Buchli, "Is Active Impedance the Key to a Breakthrough for Legged Robots?" International Symposium of Robotics Research (ISRR), 2013.
         [full article]
  • T. Boaventura, G.A. Medrano-Cerda, C. Semini, J. Buchli, D. G. Caldwell, "Stability and Performance of the Compliance Controller of the Quadruped Robot HyQ," IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2013. 
         [full article]
  • I. Havoutis, J. Ortiz, S. Bazeille, V. Barasuol, C. Semini, D. G. Caldwell, "Onboard Perception-Based Trotting and Crawling with the Hydraulic Quadruped Robot (HyQ)," IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2013.
         [full article]
  • B. Ugurlu, I. Havoutis, C. Semini, D. G. Caldwell, "Dynamic Trot-Walking with the Hydraulic Quadruped Robot - HyQ: Analytical Trajectory Generation and Active Compliance Control," IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2013.
         [full article]
  • V. Barasuol, J. Buchli, C. Semini, M. Frigerio, E. R. De Pieri, D. G. Caldwell, "A Reactive Controller Framework for Quadrupedal Locomotion on Challenging Terrain", IEEE International Conference on Robotics and Automation (ICRA), 2013.
         [full article]
  • T. Boaventura, C. Semini, J. Buchli, D. G. Caldwell, "Mechanical and Control Design Issues in Hydraulic Compliance Control", ext. abstract at the workshop on Design and Control of High-Performance Hydraulic Robots: Recent Advances and Perspectives at IEEE ICRA, 2013.
         [extended abstract]
  • M. Frigerio, C. Semini, D. G. Caldwell, J. Buchli, "Challenges in the software architecture design for autonomous legged robots", ext. abstract for the 8th workshop on Software Development and Integration in Robotics (SDIR VIII) at IEEE ICRA, 2013.
         [extended abstract]
  • M Focchi, V. Barasuol, I. Havoutis, J. Buchli,  C. Semini, D. G. Caldwell, "Local Reflex Generation for Obstacle Negotiation in Quadrupedal Locomotion", Int. Conf. on Climbing and Walking Robots (CLAWAR), 2013.
         [full article]
  • H. Khan, C. Semini, V. Barasuol, D. G. Caldwell, "Actuator sizing for highly-dynamic quadruped robots based on squat jumps and running trots",  Int. Conf. on Climbing and Walking Robots (CLAWAR), 2013.
         [full article]
  • S. Zapolsky, E. Drumwright, I. Havoutis, J. Buchli, C. Semini, "Inverse Dynamics for a Quadruped Robot Locomoting Along Slippery Surfaces", Int. Conf. on Climbing and Walking Robots (CLAWAR), 2013.
         [full article]
  • M. A. Arain, I. Havoutis, C. Semini, J. Buchli, D. G. Caldwell, "A comparison of Search-based Planners for a Legged Robot. IEEE International Workshop on Robot Motion and Control (RoMoCo), 2013.
         [full article]
  • I. Havoutis, C. Semini, D. G. Caldwell, "Virtual model control for quadrupedal trunk stabilization", Dynamic Walking, 2013.
         [extended abstract]
  • S. Bazeille, V. Barasuol, M. Focchi, I. Havoutis, M. Frigerio, J. Buchli, C. Semini, D. G. Caldwell, "Vision Enhanced Reactive Locomotion Control for Trotting on Rough Terrain", IEEE International Conference on Technologies for Practical Robot Applications (TePRA), 2013.
         [full article]
  • H. Khan, C. Semini, D. G. Caldwell, "Scaling of versatile quadruped robots for running trot", Proceedings 6th International Symposium in Adaptive Motion of Animals and Machines (AMAM), 2013.
        [extended abstract]
  • I. Havoutis, C. Semini, J. Buchli, D. G. Caldwell, "Quadrupedal trotting with active compliance ", IEEE International Conference on Mechatronics (ICM), 2013.
        [full article]

2012

  • T. Boaventura, M. Focchi, M. Frigerio, J. Buchli, C. Semini, G. A. Medrano-Cerda, D. G. Caldwell, "On the role of load motion compensation in high-performance force control", IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2012.
       [full article]
  • M. Frigerio, J. Buchli and D. G. Caldwell, "Code Generation of Algebraic Quantities for Robot Controllers", IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2012.
       [full article]
  • I. Havoutis, C. Semini, J. Buchli and D.G. Caldwell, "Progress in quadrupedal trotting with active compliance", Dynamic Walking 2012, Pensacola, Florida, USA.
        [extended abstract]
  • C. Semini, H. Khan, M. Frigerio, T. Boaventura, M. Focchi, J. Buchli and D. G. Caldwell, "Design and Scaling of Versatile Quadruped Robots", Int. Conf. on Climbing and Walking Robots (CLAWAR), 2012.
        [full article]
  • T. Boaventura, C. Semini, J. Buchli, M. Frigerio, M. Focchi, D. G. Caldwell, "Dynamic Torque Control of a Hydraulic Quadruped Robot", Proceedings IEEE International Conference on Robotics and Automation (ICRA), 2012, St. Paul, USA.
         [full article]
  • M. Frigerio, J. Buchli and D. G. Caldwell, "Model based code generation for kinematics and dynamics computations in robot controllers", 7th workshop on Software Development and Integration in Robotics (ICRA SDIR VII), St Paul, Minnesota, USA, May 2012.
        [extended abstract]
  • M. Focchi, T. Boaventura, C. Semini, M. Frigerio, J. Buchli, D. G. Caldwell, "Torque-control Based Compliant Actuation of a Quadruped Robot", Proceedings of the 12th IEEE International Workshop on Advanced Motion Control (AMC), Sarajevo, Bosnia and Herzegovina, 2012.
        [full article]
  • S. Peng, D. T. Branson, E. Guglielmino, T. Boaventura, and D. G. Caldwell, "Performance Assessment of Digital Hydraulics in a Quadruped Robot Leg", Proceedings of the 11th Biennial Conference on Engineering Systems Design and Analysis ESDA11, 2012.
       [full article]

2011

  • T. Boaventura, C. Semini, J. Buchli, D. G. Caldwell, "Actively-compliant leg for dynamic locomotion", Proceedings 5th International Symposium in Adaptive Motion of Animals and Machines (AMAM), 2011, Hyogo, Japan.
        [full article]
  • M. Frigerio, J. Buchli and D. G. Caldwell, "A Domain Specific Language for kinematic models and fast implementations of robot dynamics algorithms", 2nd International Workshop on Domain-Specific Languages and models for ROBotic systems (DSLRob’11), San Francisco, September 2011.
        [full article]
  • C. Semini, N. G. Tsagarakis, E. Guglielmino, M. Focchi, F. Cannella, and D. G. Caldwell, “Design of HyQ - a hydraulically and electrically actuated quadruped robot,”  Journal of Systems and Control Engineering, vol. 225, no. 6, pp. 831–849, 2011.
        [full article]
  • C. Semini, J. Buchli, M. Frigerio, T. Boaventura, M. Focchi, E. Guglielmino, F. Cannella, N. G. Tsagarakis, and D. G. Caldwell, “HyQ – a dynamic locomotion research platform,” in Int.l Workshop on Bio-Inspired Robots, Nantes (France), 2011.
        [full article]

2010

  • M. Focchi, E. Guglielmino, C. Semini, T. Boaventura, Y. S. Yang, D. G. Caldwell, "Control of a Hydraulically-Actuated Quadruped Robot Leg," IEEE Int. Conf. on Robotics and Automation (ICRA), 2010.
       [full article]
  • C. Semini, N. Tsagarakis, E. Guglielmino and D. G. Caldwell, "Design and experimental evaluation of the hydraulically actuated prototype leg of the HyQ robot", International Conference on Intelligent Robots and Systems (IROS), 2010 IEEE/RSJ.
       [full article]
  • C. Semini, N. Tsagarakis, E. Guglielmino, D. G. Caldwell, "Design of a Hydraulic Quadruped Robot," Workshop on Human Adaptive Mechatronics (HAM), 2010.
  • T. Boaventura, C. Semini, E. Guglielmino, V. J. De Negri, Y. Yang, D. G. Caldwell, “Gain Scheduling Control for the Hydraulic Actuation of the HyQ Robot Leg”, ABCM Symposium Series in Mechatronics, vol. 4, pp. 673-682, 2010.
       [full article]
  • Y. Yang, E. Guglielmino, J. S. Dai, T. Boaventura, and D. G. Caldwell, "Modeling of a novel 3-way rotary type electro-hydraulic valve," in Proc. IEEE Int. Conf. Information and Automation (ICIA) Conf, 2010, pp. 1463-1468.
       [full article]

2009

  • Y. S. Yang, C. Semini, E. Guglielmino, N. G. Tsagarakis, D. G. Caldwell, "Water vs. Oil Hydraulic Actuation for a Robot Leg," IEEE Int. Conf. on Mechatronics and Automation (ICMA), pp. 1940-1946, 2009.
        [full article]
  • Y. S. Yang, C. Semini, N. G. Tsagarakis, E. Guglielmino, D. G. Caldwell, "Leg Mechanisms for Hydraulically Actuated Robots," IEEE/RSJ Int. Conf. on Intelligent RObots and Systems (IROS), pp. 4669-4675, 2009.
        [full article]
  • E. Guglielmino, C. Semini, Y. S. Yang, D. G. Caldwell, H. Kogler, R. Scheidl, "Energy Efficient Fluid Power in Autonomous Legged Robotics," ASME Dynamic Systems and Control Conference (DSCC), 2009.
        [full article]

2008

  • C. Semini, N. G. Tsagarakis, B. Vanderborght, Y. S. Yang and D. G. Caldwell, "HyQ - Hydraulically Actuated Quadruped Robot: Hopping Leg Prototype," IEEE/RAS-EMBS Int. Conf. on Biomedical Robotics and Biomechatronics (BioRob), pp.593-599, 2008.
        [full article]
  • C. Semini, N. G. Tsagarakis, D. G. Caldwell, "Dynamic Tasks of a Hydraulically Actuated Quadruped Robot," Poster at Dynamic Walking Conference, Delft (The Netherlands), May 2008.
        [poster]
  • C. Semini, N. G. Tsagarakis, D. G. Caldwell, "Bio-Inspired Design of a Hydraulically Actuated Quadruped Robot [HyQ]," Poster at Robotics: Science and Systems (RSS) Conference, Zurich (Switzerland), June 2008.

  • Y. S. Yang, C. Semini, N. G. Tsagarakis, D. G. Caldwell, Y. Zhu, "Water hydraulics - A novel design of spool-type valves for enhanced dynamic performance," IEEE/ASME Int. Conf. on Advanced Intelligent Mechatronics (AIM), pp. 1308-1314, 2008.
        [full article]

  contactContact:

Project leader:  Claudio Semini, claudio.semini[a]iit.it, +39 010 71781 912

Department director:  Darwin Caldwell, darwin.caldwell[a]iit.it, +39 010 71781 427/407

Last Updated on Thursday, 17 April 2014 17:47