On the dynamics of a quadruped robot model with impedance control: Self-stabilizing high speed trot-running and period-doubling bifurcations

Lee, Jongwoo; Hyun, Dong Jin; Ahn, Jooeun; Kim, Sangbae; Hogan, Neville

doi:10.1109/iros.2014.6943260

Cited by 18 publications

(14 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The dynamic stability criteria of legged robots are still in question. Because the locomotion of a legged robot is typical periodic motion, Poincarè return map analysis has been widely adopted to evaluate locomotion stability [22,[112][113][114], from the relatively simple SLIP control model [97] to more complicated models involving specific configuration such as hybrid leg mechanisms [6]. SLIP model.…”

Section: Dynamics-based Controlmentioning

confidence: 99%

See 1 more Smart Citation

Mechanism, Actuation, Perception, and Control of Highly Dynamic Multilegged Robots: A Review

Gao

2020

Chin. J. Mech. Eng.

View full text Add to dashboard Cite

Multilegged robots have the potential to serve as assistants for humans, replacing them in performing dangerous, dull, or unclean tasks. However, they are still far from being sufficiently versatile and robust for many applications. This paper addresses key points that might yield breakthroughs for highly dynamic multilegged robots with the abilities of running (or jumping and hopping) and self-balancing. First, 21 typical multilegged robots from the last five years are surveyed, and the most impressive performances of these robots are presented. Second, current developments regarding key technologies of highly dynamic multilegged robots are reviewed in detail. The latest leg mechanisms with serial-parallel hybrid topologies and rigid–flexible coupling configurations are analyzed. Then, the development trends of three typical actuators, namely hydraulic, quasi-direct drive, and serial elastic actuators, are discussed. After that, the sensors and modeling methods used for perception are surveyed. Furthermore, this paper pays special attention to the review of control approaches since control is a great challenge for highly dynamic multilegged robots. Four dynamics-based control methods and two model-free control methods are described in detail. Third, key open topics of future research concerning the mechanism, actuation, perception, and control of highly dynamic multilegged robots are proposed. This paper reviews the state of the art development for multilegged robots, and discusses the future trend of multilegged robots.

show abstract

Section: Dynamics-based Controlmentioning

confidence: 99%

“…Furthermore, all control parameters except the virtual ground-penetration depth can be predetermined by preliminary experiments. The Cheetah 1 robot using this kind of control model with fixed control parameters can yield self-stabilizing trot-running at speeds up to 6 m/s [113].…”

Section: Software Architecturementioning

confidence: 99%

Mechanism, Actuation, Perception, and Control of Highly Dynamic Multilegged Robots: A Review

Gao

2020

Chin. J. Mech. Eng.

View full text Add to dashboard Cite

show abstract

“…Our “throw-and-catch” gait transition strategy may instantly destabilize the locomotion dynamics, and thus the performance depends on the stability and basin of attraction of each gait pattern. The stability of the trot gait with the proposed controller was already analyzed in our previous work (Lee et al., 2014). In the simulation, therefore, we present two important results to evaluate stability of the gallop gait: (1) the eigenvalues of the linearized Poincaré map of the galloping limit cycle to discuss local orbital stability; and (2) the response of the gallop gait to wide-range perturbations.…”

Section: Simulation Verification On the Performance Of The Developmentioning

confidence: 99%

“…In our previous work (Hyun et al, 2014), we demonstrated the 6 m/s trot running of the MIT Cheetah I, using the “proprioceptive impedance control”. 2 The detailed analysis of the dynamic characteristics is in Lee et al (2014).…”

Section: Introductionmentioning

confidence: 99%

Implementation of trot-to-gallop transition and subsequent gallop on the MIT Cheetah I

Hyun

Lee

Park

et al. 2016

The International Journal of Robotics Research

Self Cite

View full text Add to dashboard Cite

This paper presents a demonstration of the trot-to-gallop transition and subsequent stable gallop in a robotic quadruped. The MIT Cheetah I, a planar quadruped platform for high-speed running, achieves these tasks with a speed of 3.2 m/s (Froude number of 2.1) on a treadmill. The controller benefits from clues from biological findings and it incorporates (1) a gait pattern modulation that imposes predefined gait patterns with a proprioceptive touchdown feedback, (2) tunable equilibrium-point foot-end trajectories for four limbs that intentionally modulate ground reaction forces, and (3) programmable leg compliance that provides instantaneous reflexes to leg–ground interaction. An inertial measurement unit sensor is integrated with the controller in order to regulate leg angles of attack at touchdown. We reduce the dimension of the control parameters which describe temporal/spatial characteristics of quadruped locomotion, and the values are tuned via dynamic simulation and then experiment. Given a pre-defined virtual leg compliance and a desired angle of attack of legs, the equilibrium-point foot-end trajectories and phase relationships between four legs for stable trot and gallop gaits are found independently. We propose a simple throw-and-catch gait transition strategy which connects two stable limit cycles, the trot and the gallop, by linearly varying control parameters during the transition period. Successful gait transition is achieved in both simulation and experiment. Comprehensive analysis on the characteristics of the MIT Cheetah I experimental trot-to-gallop transition is provided. The phase portraits imply that stable limit cycles are achieved with the proposed controller in both trot and gallop, which enables the trot-to-gallop gait transition at high speed.

show abstract

“…Legged robots' high-speed locomotion is one of the challenging issues in robotic research. [11][12][13][14] However, few studies covered the qualitative change of leg stiffness with the running speed increasing.…”

Section: Introductionmentioning

confidence: 99%

Estimation of leg stiffness using an approximation to the planar spring–mass system in high-speed running

Guo

Cai

et al. 2020

International Journal of Advanced Robotic Systems

View full text Add to dashboard Cite

Leg stiffness plays a critical role in legged robots’ speed regulation. However, the analytic solutions to the differential equations of the stance phase do not exist, of course not for the exact analytical solution of stiffness. In view of the challenge in dealing with every circumstance by numerical methods, which have been adopted to tabulate approximate answers, the “harmonic motion model” was used as approximation of the stance phase. However, the wide range leg sweep angles and small fluctuations of the “center of mass” in fast movement were overlooked. In this article, we raise a “triangle motion model” with uniform forward speed, symmetric movement, and straight-line center of mass trajectory. The characters are then shifted to a quadratic equation by Taylor expansion and obtain an approximate analytical solution. Both the numerical simulation and ADAMS-Matlab co-simulation of the control system show the accuracy of the triangle motion model method in predicting leg stiffness even in the ultra-high-speed case, and it is also adaptable to low-speed cases. The study illuminates the relationship between leg stiffness and speed, and the approximation model of the planar spring–mass system may serve as an analytical tool for leg stiffness estimation in high-speed locomotion.

show abstract

On the dynamics of a quadruped robot model with impedance control: Self-stabilizing high speed trot-running and period-doubling bifurcations

Cited by 18 publications

References 29 publications

Mechanism, Actuation, Perception, and Control of Highly Dynamic Multilegged Robots: A Review

Mechanism, Actuation, Perception, and Control of Highly Dynamic Multilegged Robots: A Review

Implementation of trot-to-gallop transition and subsequent gallop on the MIT Cheetah I

Estimation of leg stiffness using an approximation to the planar spring–mass system in high-speed running

Contact Info

Product

Resources

About