scholarly journals Research on Walking Gait of Biped Robot Based on a Modified CPG Model

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Qiang Lu ◽  
Juan Tian
Keyword(s):  
Musculoskeletal System ◽  
Biped Robot ◽  
Cerebellar Model Articulation Controller ◽  
Stable Periodic Solution ◽  
Rhythmic Movements ◽  
Credit Assignment ◽  
Modified Model ◽  
Walking Gait ◽  
Neurophysiological Studies ◽  
Stable Periodic

The neurophysiological studies of animals locomotion have verified that the fundamental rhythmic movements of animals are generated by the central pattern generator (CPG). Many CPG models have been proposed by scientific researchers. In this paper, a modified CPG model whose output function issin(x)is presented. The paper proves that the modified model has stable periodic solution and characteristics of the rhythmic movement using the Lyapunov judgement theorem and the phase diagram. A modified locomotion model is established in which the credit-assignment cerebellar model articulation controller (CA-CMAC) algorithm is used to realize the pattern mapping between the CPG output and the musculoskeletal system. And a seven-link biped robot is employed to simulate cyclic walking gait in order to test the validity of the locomotion model. The main findings include the following. (1) The modified CPG model can generate spontaneous oscillations which correspond to biological signals. (2) The analysis of the modified locomotion model reveals that the CA-CMAC algorithm can be used to realize the pattern mapping between the CPG output and the musculoskeletal system.

scholarly journals Online Biped Walking Pattern Generation with Contact Consistency

2015 ◽  
Vol 4 (1) ◽  
pp. 19
Author(s):  
Wenqi Hou ◽  
Jian Wang ◽  
Jianwen Wang ◽  
Hongxu Ma
Keyword(s):  
Biped Robot ◽  
Gait Pattern ◽  
Pattern Generation ◽  
Task Space ◽  
Biped Walking ◽  
Foot Placement ◽  
Walking Gait ◽  
Walking Pattern ◽  
Generating Method ◽  
Stable Periodic

In this paper, a novel online biped walking gait pattern generating method with contact consistency is proposed. Generally, it’s desirable that there is no foot-ground slipping during biped walking. By treating the hip of the biped robot as a linear inverted pendulum (LIP), a foot placement controller that takes the contact consistency into account is proposed to tracking the desired orbit energy. By selecting the hip’s horizontal locomotion as the parameter, the trajectories in task space for walking are planned. A task space controller without calculating the inversion of inertial matrix is presented. Simulation experiments are implemented on a virtual 5-link point foot biped robot. The results show the effectiveness of the walking pattern generating method which can realize a stable periodic gait cycle without slipping and falling even suffering a sudden disturbance.

scholarly journals Permanence and Periodic Solution of Predator-Prey System with Holling Type Functional Response and Impulses

2007 ◽  
Vol 2007 ◽  
pp. 1-15 ◽  
Author(s):  
Weibing Wang ◽  
Jianhua Shen ◽  
Juan J. Nieto
Keyword(s):  
Periodic Solution ◽  
Functional Response ◽  
Impulsive Effect ◽  
Two Dimensional ◽  
Stable Periodic Solution ◽  
Predator Prey ◽  
Prey System ◽  
Stable Periodic ◽  
Holling Type Functional Response

We considered a nonautonomous two dimensional predator-prey system with impulsive effect. Conditions for the permanence of the system and for the existence of a unique stable periodic solution are obtained.

scholarly journals Comparative stable walking gait optimization for small-sized biped robot using meta-heuristic optimization algorithms

2018 ◽  
Vol 40 (4) ◽  
pp. 407-424
Author(s):  
Tran Thien Huan ◽  
Ho Pham Huy Anh
Keyword(s):  
Humanoid Robot ◽  
Differential Evolution Algorithm ◽  
Biped Robot ◽  
The Novel ◽  
Biped Robots ◽  
Walking Gait ◽  
Gait Parameters ◽  
Lift Height ◽  
Evolution Algorithm ◽  
Gait Optimization

This paper proposes a new way to optimize the biped walking gait design for biped robots that permits stable and robust stepping with pre-set foot lifting magnitude. The new meta-heuristic CFO-Central Force Optimization algorithm is initiatively applied to optimize the biped gait parameters as to ensure to keep biped robot walking robustly and steadily. The efficiency of the proposed method is compared with the GA-Genetic Algorithm, PSO-Particle Swarm Optimization and Modified Differential Evolution algorithm (MDE). The simulated and experimental results carried on the prototype small-sized humanoid robot demonstrate that the novel meta-heuristic CFO algorithm offers an efficient and stable walking gait for biped robots with respect to a pre-set of foot-lift height value.

Stable walking control of a 3D biped robot with foot rotation

Robotica ◽  
2013 ◽  
Vol 32 (4) ◽  
pp. 551-570 ◽  
Author(s):  
Ting Wang ◽  
Christine Chevallereau ◽  
David Tlalolini
Keyword(s):  
Linear Combination ◽  
Biped Robot ◽  
Control Law ◽  
Reference Trajectory ◽  
Joint Angles ◽  
Flat Foot ◽  
Loop Control ◽  
Walking Gait ◽  
Initial Errors ◽  
Rotation Phase

SUMMARYIn order to obtain a more human-like walking and less energy consumption, ait foot rotation phaseis considered in the single support phase of a 3D biped robot, in which the stance heel lifts from the ground and the stance foot rotates about the toe. Since there is no actuation at the toe, a walking phase of the robot is composed of a fully actuated phase and an under-actuated phase. The objective of this paper is to present an asymptotically stable walking controller that integrates these two phases. To get around the under-actuation issue, a strict monotonic parameter of the robot is used to describe the reference trajectory instead of using the time parameter. The overall control law consists of a zero moment point (ZMP) controller, a swing ankle rotation controller and a partial joint angles controller. The ZMP controller guarantees that the ZMP follows the desired ZMP. The swing ankle rotation controller assures a flat-foot impact at the end of the swinging phase. Each of these controllers creates two constraints on joint accelerations. In order to determine all the desired joint accelerations from the control law, a partial joint angles controller is implemented. A word “partial” emphasizes the fact that not all the joint angles can be controlled. The outputs controlled by a partial joint angles controller are defined as a linear combination of all the joint angles. The most important question addressed in this paper is how this linear combination can be defined in order to ensure walking stability. The stability of the walking gait under closed-loop control is evaluated with the linearization of the restricted Poincaré map of the hybrid zero dynamics. Finally, simulation results validate the effectiveness of the control law even in presence of initial errors and modelling errors.

ON THE INFLUENCE OF THE RESONANT FREQUENCIES RATIO ON A STABLE PERIODIC SOLUTION OF TWO IMPACTING OSCILLATORS

2006 ◽  
Vol 16 (12) ◽  
pp. 3707-3715 ◽  
Author(s):  
KRZYSZTOF CZOLCZYNSKI ◽  
TOMASZ KAPITANIAK
Keyword(s):  
Periodic Solution ◽  
Periodic Motion ◽  
Stable Periodic Solution ◽  
Resonant Frequencies ◽  
Stable Periodic

A system that consists of two impacting oscillators with damping has been considered in this paper. The goal of the studies was to determine the relation between the values of resonant frequencies of the oscillators and the existence of their stable periodic motion. This paper indicates various origins of the periodicity of motion and offers a some advice to the designers of systems with impacts. Especially, the results of the considerations point out some potentially dangerous consequences of the improper value of the resonant frequencies ratio.

scholarly journals Global asymptotic stability in a periodic Lotka-Volterra system

1985 ◽  
Vol 27 (1) ◽  
pp. 66-72 ◽  
Author(s):  
K. Gopalsamy
Keyword(s):  
Periodic Solution ◽  
Asymptotic Stability ◽  
Global Asymptotic Stability ◽  
Sufficient Conditions ◽  
Asymptotically Stable ◽  
Stable Periodic Solution ◽  
Volterra System ◽  
Periodic Coefficients ◽  
Globally Asymptotically Stable ◽  
Stable Periodic

AbstractA set of easily verifiable sufficient conditions are obtained for the existence of a globally asymptotically stable periodic solution in a Lotka-Volterra system with periodic coefficients.

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