The Yobotics-IHMC Lower Body Humanoid Robot

Pratt, Jerry; Krupp, Ben; Ragusila, Victor; Rebula, John R.; Koolen, Twan; Nieuwenhuizen, N. Van; Shake, C. L.; Craig, Travis; Taylor, John R.; Watkins, Greg; Neuhaus, Peter; Johnson, Matthew; Shooter, Steven B.; Buffinton, Keith W.; Canas, Fabian; Carff, John; Howell, William C.

doi:10.1109/iros.2009.5354430

Cited by 20 publications

(9 citation statements)

References 5 publications

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“…In 2000, Pratt (2000b) achieved lateral stability for a simulated 3D robot using the capture angle, which is the azimuth of the capture point when written in polar coordinates. Capture point-based push recovery on a physical robot was first shown in Pratt et al (2009). Walking controllers based on the instantaneous capture point have recently started to become more popular.…”

Section: Instantaneous Capture Point-based Controlmentioning

confidence: 99%

Capturability-based analysis and control of legged locomotion, Part 2: Application to M2V2, a lower-body humanoid

Pratt

Koolen

Boer

et al. 2012

The International Journal of Robotics Research

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241

189

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This two-part paper discusses the analysis and control of legged locomotion in terms of N-step capturability: the ability of a legged system to come to a stop without falling by taking N or fewer steps. We consider this ability to be crucial to legged locomotion and a useful, yet not overly restrictive criterion for stability. Part 1 introduced the N-step capturability framework and showed how to obtain capture regions and control sequences for simplified gait models. In Part 2, we describe an algorithm that uses these results as approximations to control a humanoid robot. The main contributions of this part are (1) step location adjustment using the 1-step capture region, (2) novel instantaneous capture point control strategies, and 3) an experimental evaluation of the 1-step capturability margin. The presented algorithm was tested using M2V2, a 3D force-controlled bipedal robot with 12 actuated degrees of freedom in the legs, both in simulation and in physical experiments. The physical robot was able to recover from forward and sideways pushes of up to 21 Ns while balancing on one leg and stepping to regain balance. The simulated robot was able to recover from sideways pushes of up to 15 Ns while walking, and walked across randomly placed stepping stones.

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Section: Instantaneous Capture Point-based Controlmentioning

confidence: 99%

Capturability-based analysis and control of legged locomotion, Part 2: Application to M2V2, a lower-body humanoid

Pratt

Koolen

Boer

et al. 2012

The International Journal of Robotics Research

Self Cite

241

189

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show abstract

“…Other examples such as Honda’s ASIMO Hirose and Ogawa (2006) and Samsung’s Mahru III Kwon et al (2007) have demonstrated capabilities such as quasi-static walking, running, dancing, and climbing stairs inside buildings. Or, Yobotics-IHMC lower body, humanoid biped has shown recovery from severe pushes Pratt et al (2009) .…”

Section: Introductionmentioning

confidence: 99%

Control of Thruster-Assisted, Bipedal Legged Locomotion of the Harpy Robot

2021

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Fast constraint satisfaction, frontal dynamics stabilization, and avoiding fallovers in dynamic, bipedal walkers can be pretty challenging. The challenges include underactuation, vulnerability to external perturbations, and high computational complexity that arise when accounting for the system full-dynamics and environmental interactions. In this work, we study the potential roles of thrusters in addressing some of these locomotion challenges in bipedal robotics. We will introduce a thruster-assisted bipedal robot called Harpy. We will capitalize on Harpy’s unique design to propose an optimization-free approach to satisfy gait feasibility conditions. In this thruster-assisted legged locomotion, the reference trajectories can be manipulated to fulfill constraints brought on by ground contact and those prescribed for states and inputs. Unintended changes to the trajectories, especially those optimized to produce periodic orbits, can adversely affect gait stability and hybrid invariance. We will show our approach can still guarantee stability and hybrid invariance of the gaits by employing the thrusters in Harpy. We will also show that the thrusters can be leveraged to robustify the gaits by dodging fallovers or jumping over large obstacles.

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“…Other than these successful examples, a large number of underactuated and fully actuated bipedal robots have also been introduced. Agility Robotics' Cassie [3], Honda's ASIMO [4] and Samsung's Mahru III [5] are capable of walking, running, dancing and going up and down stairs, and the Yobotics-IHMC [6] biped can recover from pushes. Despite these accomplishments, these systems are prone to falling over when navigating rough terrains.…”

Section: Introductionmentioning

confidence: 99%

Unilateral Ground Contact Force Regulations in Thruster-Assisted Legged Locomotion

Sihite¹,

Dangol²,

Ramezani³

2021

Preprint

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In this paper, we study the regulation of the Ground Contact Forces (GRF) in thruster-assisted legged locomotion. We will employ Reference Governors (RGs) for enforcing GRF constraints in Harpy model which is a bipedal robot that is being developed at Northeastern University. Optimization-based methods and whole body control are widely used for enforcing the no-slip constraints in legged locomotion which can be very computationally expensive. In contrast, RGs can enforce these constraints by manipulating joint reference trajectories using Lyapunov stability arguments which can be computed much faster. The addition of the thrusters in our model allows to manipulate the gait parameters and the GRF without sacrificing the locomotion stability.

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The Yobotics-IHMC Lower Body Humanoid Robot

Cited by 20 publications

References 5 publications

Capturability-based analysis and control of legged locomotion, Part 2: Application to M2V2, a lower-body humanoid

Capturability-based analysis and control of legged locomotion, Part 2: Application to M2V2, a lower-body humanoid

Control of Thruster-Assisted, Bipedal Legged Locomotion of the Harpy Robot

Unilateral Ground Contact Force Regulations in Thruster-Assisted Legged Locomotion

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