scholarly journals Leg design for biped locomotion with mono-articular and bi-articular linear actuation

2021 ◽  
Vol 156 ◽  
pp. 104138
Author(s):  
Christine Chevallereau ◽  
Philippe Wenger ◽  
Yannick Aoustin ◽  
Franck Mercier ◽  
Nicolas Delanoue ◽  
...  
Keyword(s):  
2021 ◽  
Vol 3 (9) ◽  
Author(s):  
Mohammadreza Kasaei ◽  
Ali Ahmadi ◽  
Nuno Lau ◽  
Artur Pereira

AbstractBiped robots are inherently unstable because of their complex kinematics as well as dynamics. Despite many research efforts in developing biped locomotion, the performance of biped locomotion is still far from the expectations. This paper proposes a model-based framework to generate stable biped locomotion. The core of this framework is an abstract dynamics model which is composed of three masses to consider the dynamics of stance leg, torso, and swing leg for minimizing the tracking problems. According to this dynamics model, we propose a modular walking reference trajectories planner which takes into account obstacles to plan all the references. Moreover, this dynamics model is used to formulate the controller as a Model Predictive Control (MPC) scheme which can consider some constraints in the states of the system, inputs, outputs, and also mixed input-output. The performance and the robustness of the proposed framework are validated by performing several numerical simulations using MATLAB. Moreover, the framework is deployed on a simulated torque-controlled humanoid to verify its performance and robustness. The simulation results show that the proposed framework is capable of generating biped locomotion robustly.


Author(s):  
E. F. Fichter ◽  
D. R. Kerr

Abstract A walking machine design originating from observations of insects is presented. The primary concept derived from insects is a leg used to apply force to the body without applying significant moments about the point of body attachment. This is accomplished with legs which have kinematic equivalents to ball-and-socket joints at body attachment and ground contact, with joints in the middle which only change distance between body and ground. Standing and walking with 6 legs of this design requires careful attention to static equilibrium equations but does not necessitate a control system which actively distributes forces to the legs. This paper considers necessary observational data, assumptions on which control is based, mathematical development for control and problems such as foot slip.


Author(s):  
Ning-Xin Chen ◽  
Shin-Ming Song

Abstract The leg mechanism of a walking machine has a strong influence on the performance of the machine. A successful leg mechanism should be energy efficient, compact in size, strong and simple. In order to achieve good energy efficiency, a walking machine leg should be able to generate an exact or approximate straight line at the foot with only one driving actuator. This paper deals with the synthesis and analysis of a new leg mechanism — the planetary gear leg mechanism. Four types of planetary gear legs are studied. By the SUMT optimization method, a 20 inch tall leg is able to generate an approximate straight line trajectory with a maximum deviation of 0.12805 inches in a 20 inch stroke. The direct and inverse kinematics and velocities of the legs are analyzed. Also, the distribution of actuator force/moment during walking are studied. The results show that this leg design has great potential to be used as a practical walking machine leg.


2013 ◽  
Author(s):  
C. Teixeira ◽  
L. Costa ◽  
C. Santos
Keyword(s):  

Author(s):  
Sayat Ibrayev ◽  
Nutpulla Jamalov ◽  
Amandyk Tuleshov ◽  
Assylbek Jomartov ◽  
Aidos Ibrayev ◽  
...  

Author(s):  
Kevin C. Galloway ◽  
Jonathan E. Clark ◽  
Daniel E. Koditschek

Passively compliant legs have been instrumental in the development of dynamically running legged robots. Having properly tuned leg springs is essential for stable, robust and energetically efficient running at high speeds. Recent simulation studies indicate that having variable stiffness legs, as animals do, can significantly improve the speed and stability of these robots in changing environmental conditions. However, to date, the mechanical complexities of designing usefully robust tunable passive compliance into legs has precluded their implementation on practical running robots. This paper describes a new design of a “structurally controlled variable stiffness” leg for a hexapedal running robot. This new leg improves on previous designs’ performance and enables runtime modification of leg stiffness in a small, lightweight, and rugged package. Modeling and leg test experiments are presented that characterize the improvement in stiffness range, energy storage, and dynamic coupling properties of these legs. We conclude that this variable stiffness leg design is now ready for implementation and testing on a dynamical running robot.


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