Stable running of a planar underactuated biped robot

Hu, Yong; Yan, Gangfeng; Lin, Zhiyun

doi:10.1017/s0263574710000512

Cited by 19 publications

(24 citation statements)

References 31 publications

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“…Qualitatively speaking, its overall shape appears to be in agreement with the results in [23] for a simple biped model with only three point masses.…”

Section: Results: Straight Leg Bipedsupporting

confidence: 83%

“…Figure 8 and 10 show convergence with the limit cycles using control law (30), and Figure 9 and 11 show their control efforts, which approach the fixed point values of the gait and reach a steady state after about 15 steps. The shape of the passive limit cycle for running on horizontal terrain in Figure 8 is similar to the limit cycle of a biped model with three point masses and without legs inertias in [23], because both of the models have massless springy feet. Moreover, for both models the closed-loop control effort converges on zero as the system converges on a passive gait ( Figure 9).…”

Section: Results: Straight Leg Bipedmentioning

confidence: 76%

“…Hyon et al [22] proposed a controller based upon an energy preservation strategy for a one legged hopping robot and then applied it to a planar biped robot with springy legs and a torso. Hu et al [23] investigated unstable passive running gaits for a telescoping springy biped model with massless point feet, and stabilized them using event-based LQR control similar to McGeer [19]. These works were confined to biped models with massless springy legs on horizontal terrain that have passive running gaits, and could not be applied to real biped robot models that do not have a passive limit cycle.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Compliant Leg Architectures and a Linear Control Strategy for the Stable Running of Planar Biped Robots

Dadashzadeh

Mahjoob

Bahrami

et al. 2013

International Journal of Advanced Robotic Systems

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This paper investigates two fundamental structures for biped robots and a control strategy to achieve stable biped running. The first biped structure contains straight legs with telescopic springs, and the second one contains knees with compliant elements in parallel with the motors. With both configurations we can use a standard linear discrete-time state-feedback control strategy to achieve an active periodic stable biped running gait, using the Poincare map of one complete step to produce the discrete-time model. In this case, the Poincare map describes an open-loop system with an unstable equilibrium, requiring a closedloop control for stabilization. The discretization contains a stance phase, a flight phase and a touch-down. In the first approach, the control signals remain constant during each phase, while in the second approach both phases are discretized into a number of constant-torque intervals, so that its formulation can be applied easily to stabilize any active biped running gait. Simulation results with both the straight-legged and the kneed biped model demonstrate stable gaits on both horizontal and inclined surfaces.

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“…Qualitatively speaking, its overall shape appears to be in agreement with the results in [23] for a simple biped model with only three point masses.…”

Section: Results: Straight Leg Bipedsupporting

confidence: 83%

Section: Results: Straight Leg Bipedmentioning

confidence: 76%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Compliant Leg Architectures and a Linear Control Strategy for the Stable Running of Planar Biped Robots

Dadashzadeh

Mahjoob

Bahrami

et al. 2013

International Journal of Advanced Robotic Systems

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“…The evolutions of the absolute angles and angular velocities are different from the biped running robot without knees, see [6]. The values of angular velocities have a great change in stance phase, however, almost keep the same in the flight phase.…”

Section: Limit Cycle Analysismentioning

confidence: 93%

“…Compass-like biped has demonstrated this property by stabilizing a passive limit cycle in [6], while a biped with knees has not been investigated. Based on the effect of leg compliance originating from joint level on running stability [18], we designed our robot with only torque springs acting on the knee joints, and then incorporating compliance to the running dynamic.…”

Section: Introductionmentioning

confidence: 99%

Stable running on a kneed biped robot with only hip-joint actuation

Yang

Lin

Yan

2012

Proceedings of the 10th World Congress on Intelligent Control and Automation

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Passive dynamic locomotion is well-known for its fabulous advantages in energy efficiency. In this paper we focus on the level passive running problem of a kneed biped. The knee joints of our robot model are elastic with torque springs. So energy dissipation is avoided at landing. Passive gaits have been firstly demonstrated on this kneed biped in this paper, yet they are not stable. Note that there is only one actuation at the hip joint. The robot thus has three degrees of under actuation, which increases the difficulty of control design. We derive an event-based control law to stabilize the system, and add energy shaping part to enlarge the basin of attraction as well as provide additional robustness. The effectiveness of our approach has been verified by numerical simulations.

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Finite-time control strategy for the running of a telescopic leg biped robot

Doosti

Mahjoob

Dadashzadeh

2019

J Braz. Soc. Mech. Sci. Eng.

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Designing stable and efficient control methods for walking and running of biped robots has been a challenge over the past years. The goal of this paper is to design a finite-time controller to stabilize the running gait of a compliant leg biped robot. The biped model consists of two springy telescopic legs with flat feet. The robot model has five actuators including a torque actuator at the hip joint, two torque actuators at the ankle joints and two force actuators at the legs prismatic joints parallel to the springs. Dynamic equations of stance phase, flight phase and touchdown event are derived to build the dynamic model of a complete step of running. This robot model has passive periodic running gaits which are unstable. The controller aims to stabilize the gaits around the desired limit cycles and reject disturbances. Finite-time sliding mode control is used to design controller for the stance phase; the flight phase remains passive. Starting from various deviated initial conditions, the state space trajectory of the system with the designed control law is derived and its convergence to the desired trajectory is shown. The result of the controller is also compared with an event-based linear controller from previous references.

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Stable running of a planar underactuated biped robot

Cited by 19 publications

References 31 publications

Compliant Leg Architectures and a Linear Control Strategy for the Stable Running of Planar Biped Robots

Compliant Leg Architectures and a Linear Control Strategy for the Stable Running of Planar Biped Robots

Stable running on a kneed biped robot with only hip-joint actuation

Finite-time control strategy for the running of a telescopic leg biped robot

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