scholarly journals On a CPG-Based Hexapod Robot: AmphiHex-II With Variable Stiffness Legs

2018 ◽  
Vol 23 (2) ◽  
pp. 542-551 ◽  
Author(s):  
Bin Zhong ◽  
Shiwu Zhang ◽  
Min Xu ◽  
Youcheng Zhou ◽  
Tao Fang ◽  
...  
Keyword(s):  
Variable Stiffness ◽  
Hexapod Robot

scholarly journals A novel stiffness model for a wall-climbing hexapod robot based on nonlinear variable stiffness

2018 ◽  
Vol 10 (1) ◽  
pp. 168781401775248 ◽  
Author(s):  
Bin He ◽  
Shoulin Xu ◽  
Zhipeng Wang
Keyword(s):  
Structural Parameters ◽  
Variable Stiffness ◽  
Load Force ◽  
Nonlinear Stiffness ◽  
Hexapod Robot ◽  
Maximum Stiffness ◽  
Stiffness Model ◽  
Linear And Nonlinear ◽  
Serial Mechanism ◽  
Selection Of

In this article, the most contribution is to propose a novel general stiffness model to analyze the stiffness of a wall-climbing hexapod robot. First, we propose a new general stiffness model of serial mechanism, which includes the linear and nonlinear stiffness models. By comparison, the nonlinear stiffness model is a variable stiffness model which introduces the external load force as a variable, obtaining that the nonlinear stiffness model can greatly improve the accuracy of stiffness model than linear stiffness model. Then, the stiffness model of one leg of the robot and the overall stiffness model of the robot are derived based on the general stiffness model. Next, to improve the stiffness of the robot, a new minimum and maximum stiffness are introduced, which provide with effective reference for the selection and optimization of the structural parameters of the robot. Finally, we develop a new wall-climbing hexapod robot based on selection and optimization of the structural parameters, then the experiments are used to show that the selection of structure parameters of the robot effectively improve the stiffness of the robot.

Modeling the Compliance of a Variable Stiffness C-Shaped Leg Using Castigliano’s Theorem

2010 ◽  
Author(s):  
Yasemin O¨. Aydın ◽  
Kevin C. Galloway ◽  
Yigit Yazicioglu ◽  
Daniel E. Koditschek
Keyword(s):  
Rigid Body ◽  
Closed Form ◽  
Variable Stiffness ◽  
Dynamic Equations ◽  
Hexapod Robot ◽  
Static Loads ◽  
Compliant Robot ◽  
Circular Beam ◽  
Robot Leg ◽  
Castigliano’S Theorem

This paper discusses the application of Castigliano’s Theorem to a half circular beam intended for use as a shaped, tunable, passively compliant robot leg. We present closed-form equations characterizing the deflection behavior of the beam (whose compliance properties vary along the leg) under appropriate loads. We compare the accuracy of this analytical representation to that of a Pseudo Rigid Body (PRB) approximation in predicting the data obtained by measuring the deflection of a physical half-circular beam under the application of known static loads. We briefly discuss the further application of the new model for solving the dynamic equations of a hexapod robot with a C-shaped leg.

Design of Variable Stiffness Cylinder with Holes Under Bending for Maximum Buckling Load Using Lamination Parameters

2019 ◽  
Author(s):  
Mazen Albazzan ◽  
Brian Tatting ◽  
Ramy Harik ◽  
Zafer Gürdal ◽  
Adriana Blom-Schieber ◽  
...  
Keyword(s):  
Variable Stiffness ◽  
Buckling Load ◽  
Lamination Parameters

A Cockroach-Like Hexapod Robot for Natural Terrain Locomotion

1997 ◽  
Author(s):  
Randall D. Beer ◽  
Roger Quinn ◽  
Roy Ritzmann ◽  
Hillel Chiel
Keyword(s):  
Hexapod Robot ◽  
Natural Terrain

Design of a Variable Stiffness Spar

1997 ◽  
Author(s):  
Sridhar Kota ◽  
Joel Hetrick ◽  
Laxman Saggere
Keyword(s):  
Variable Stiffness

scholarly journals Getting grip in changing environments: the effect of friction anisotropy inversion on robot locomotion

2021 ◽  
Vol 127 (5) ◽  
Author(s):  
Halvor T. Tramsen ◽  
Lars Heepe ◽  
Jettanan Homchanthanakul ◽  
Florentin Wörgötter ◽  
Stanislav N. Gorb ◽  
...  
Keyword(s):  
Energy Efficient ◽  
Legged Locomotion ◽  
Hexapod Robot ◽  
Friction Anisotropy ◽  
Anisotropic Friction ◽  
Walking Behavior ◽  
Robot Locomotion ◽  
Computational Morphology ◽  
Anisotropic Structures ◽  
Walking Environment

AbstractLegged locomotion of robots can be greatly improved by bioinspired tribological structures and by applying the principles of computational morphology to achieve fast and energy-efficient walking. In a previous research, we mounted shark skin on the belly of a hexapod robot to show that the passive anisotropic friction properties of this structure enhance locomotion efficiency, resulting in a stronger grip on varying walking surfaces. This study builds upon these results by using a previously investigated sawtooth structure as a model surface on a legged robot to systematically examine the influences of different material and surface properties on the resulting friction coefficients and the walking behavior of the robot. By employing different surfaces and by varying the stiffness and orientation of the anisotropic structures, we conclude that with having prior knowledge about the walking environment in combination with the tribological properties of these structures, we can greatly improve the robot’s locomotion efficiency.

scholarly journals A Variable Parameter Ambient Vibration Control Method Based on Quasi-Zero Stiffness in Robotic Drilling Systems

Machines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 67
Author(s):  
Laixi Zhang ◽  
Chenming Zhao ◽  
Feng Qian ◽  
Jaspreet Singh Dhupia ◽  
Mingliang Wu
Keyword(s):  
Vibration Control ◽  
Vibration Isolation ◽  
Control Method ◽  
Control Strategies ◽  
Equations Of Motion ◽  
Variable Parameter ◽  
Harmonic Balance Method ◽  
Variable Stiffness ◽  
Ambient Vibration ◽  
Robotic Drilling

Vibrations in the aircraft assembly building will affect the precision of the robotic drilling system. A variable stiffness and damping semiactive vibration control mechanism with quasi-zero stiffness characteristics is developed. The quasi-zero stiffness of the mechanism is realized by the parallel connection of four vertically arranged bearing springs and two symmetrical horizontally arranged negative stiffness elements. Firstly, the quasi-zero stiffness parameters of the mechanism at the static equilibrium position are obtained through analysis. Secondly, the harmonic balance method is used to deal with the differential equations of motion. The effects of every parameter on the displacement transmissibility are analyzed, and the variable parameter control strategies are proposed. Finally, the system responses of the passive and semiactive vibration isolation mechanisms to the segmental variable frequency excitations are compared through virtual prototype experiments. The results show that the frequency range of vibration isolation is widened, and the stability of the vibration control system is effectively improved without resonance through the semiactive vibration control method. It is of innovative significance for ambient vibration control in robotic drilling systems.

scholarly journals Design of a Variable-Stiffness Compliant Skin for a Morphing Leading Edge

2021 ◽  
Vol 11 (7) ◽  
pp. 3165
Author(s):  
Zhigang Wang ◽  
Yu Yang
Keyword(s):  
Composite Laminate ◽  
Large Scale ◽  
Design Method ◽  
Leading Edge ◽  
Variable Stiffness ◽  
Manufacturing Constraints ◽  
Aircraft Wing ◽  
Noise Abatement ◽  
Civil Aircraft ◽  
Final Profile

A seamless and smooth morphing leading edge has remarkable potential for noise abatement and drag reduction of civil aircraft. Variable-stiffness compliant skin based on tailored composite laminate is a concept with great potential for morphing leading edge, but the currently proposed methods have difficulty in taking the manufacturing constraints or layup sequence into account during the optimization process. This paper proposes an innovative two-step design method for a variable-stiffness compliant skin of a morphing leading edge, which includes layup optimization and layup adjustment. The combination of these two steps can not only improve the deformation accuracy of the final profile of the compliant skin but also easily and effectively determine the layup sequence of the composite layup. With the design framework, an optimization model is created for a variable-stiffness compliant skin, and an adjustment method for its layups is presented. Finally, the deformed profiles between the directly optimized layups and the adjusted ones are compared to verify its morphing ability and accuracy. The final results demonstrate that the obtained deforming ability and accuracy are suitable for a large-scale aircraft wing.

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