Passive Whole-Body Control for Quadruped Robots: Experimental Validation Over Challenging Terrain

Shamel Fahmi, Carlos Mastalli, Michele Focchi, Claudio Semini

Research output: Contribution to journalArticlepeer-review


We present experimental results using a passive whole-body control approach for quadruped robots that achieves dynamic locomotion while compliantly balancing the robot’s trunk. We formulate the motion tracking as a quadratic program that takes into account the full robot rigid body dynamics, the actuation limits, the joint limits, and the contact interaction. We analyze the controller’s robustness against inaccurate friction coefficient estimates and unstable footholds, as well as its capability to redistribute the load as a consequence of enforcing actuation limits. Additionally, we present practical implementation details gained from the experience with the real platform. Extensive experimental trials on the 90 kg hydraulically actuated quadruped robot validate the capabilities of this controller under various terrain conditions and gaits. The proposed approach is superior for accurate execution of highly dynamic motions with respect to the current state of the art.
Original languageEnglish
Pages (from-to)2553-2560
Number of pages8
JournalIEEE Robotics and Automation Letters
Issue number3
Publication statusPublished - 1 Apr 2019
Event2019 IEEE International Conference on Soft Robotics - Seoul, Korea, Republic of
Duration: 14 Apr 201918 Apr 2019
Conference number: 2


  • actuators
  • friction
  • hydraulic actuators
  • legged locomotion
  • motion control
  • quadratic programming
  • robot dynamics
  • extensive experimental trials
  • terrain conditions
  • gaits
  • highly dynamic motions
  • experimental validation
  • challenging terrain
  • experimental results
  • dynamic locomotion
  • motion tracking
  • quadratic program
  • robot rigid body dynamics
  • actuation limits
  • joint limits
  • contact interaction
  • inaccurate friction coefficient estimates
  • hydraulically actuated quadruped robots
  • passive whole-body control approach
  • robot trunk
  • mass 90.0 kg
  • Legged locomotion
  • Task analysis
  • Dynamics
  • Foot
  • Robot kinematics
  • Optimization
  • Whole-body control
  • quadrupedal locomotion
  • optimization
  • passivity
  • active impedance

Fingerprint Dive into the research topics of 'Passive Whole-Body Control for Quadruped Robots: Experimental Validation Over Challenging Terrain'. Together they form a unique fingerprint.

Cite this