Numerical Investigation of Nonlinear Dynamics of a Pneumatic Artificial Muscle With Hard Excitation

2020 ◽  
Vol 15 (4) ◽  
Author(s):  
Bhaben Kalita ◽  
Santosha K. Dwivedy
Keyword(s):  
Nonlinear Dynamics ◽  
Resonance Condition ◽  
Basin Of Attraction ◽  
Artificial Muscle ◽  
Phase Portraits ◽  
System Response ◽  
Pneumatic Artificial Muscle ◽  
Superharmonic Resonance ◽  
System Parameters ◽  
Hard Excitation

Abstract In this work, a numerical analysis has been carried out to study the nonlinear dynamics of a system with pneumatic artificial muscle (PAM). The system is modeled as a single degree-of-freedom system and the governing nonlinear equation of motion has been derived to study the various responses of the system. The system is subjected to hard excitation and hence the subharmonic and superharmonic resonance conditions have been studied. The second-order method of multiple scales (MMS) has been used to find the response, stability, and bifurcations of the system. The effect of various system parameters on the system response has been studied using time response, phase portraits, and basin of attraction. In these responses, while the saddle node bifurcation is found in both super and subharmonic resonance conditions, the Hopf bifurcation is found only in superharmonic resonance condition. By changing different system parameters, it has been shown that the response with three periods leads to chaotic response for superharmonic resonance condition. This study will find applications in the design of PAM actuators.

scholarly journals Pneumatic Artificial Muscle Actuator Under Parametric and Hard Excitations

2021 ◽  
Author(s):  
BHABEN KALITA ◽  
SANTOSHA K. DWIVEDY
Keyword(s):  
Governing Equation ◽  
Multiple Scales ◽  
Method Of Multiple Scales ◽  
Basin Of Attraction ◽  
Artificial Muscle ◽  
Equation Of Motion ◽  
Phase Portraits ◽  
System Response ◽  
Pneumatic Artificial Muscle ◽  
Stability And Bifurcations

Abstract In this work, a single degree of freedom system consisting of a mass and a Pneumatic Artificial Muscle (PAM) subjected to time varying pressure inside the muscle is considered. The system is subjected to hard excitation and the governing equation of motion is found to be that of a nonlinear forced and parametrically excited system under super- and sub-harmonic resonance conditions. The solution of the nonlinear governing equation of motion is obtained using the method of multiple scales (MMS). The time and frequency response, phase portraits and basin of attraction have been plotted to study the system response along with the stability and bifurcations. Further, the different muscle parameters have been evaluated by performing experiments which are further used for numerically evaluating the system response using the theoretically obtained closed form equations. The responses obtained from the experiments are found to be in good agreement with those obtained from the method of multiple scales. With the help of examples, the procedure to obtain the safe operating range of different system parameters have been illustrated.

scholarly journals Dynamic analysis of a parametrically excited golden Muga silk embedded pneumatic artificial muscle

2018 ◽  
Vol 211 ◽  
pp. 02008 ◽  
Author(s):  
Bhaben Kalita ◽  
S. K. Dwivedy
Keyword(s):  
Dynamic Analysis ◽  
Multiple Scales ◽  
Method Of Multiple Scales ◽  
Quadratic Function ◽  
Artificial Muscle ◽  
Equation Of Motion ◽  
Time Response ◽  
Phase Portraits ◽  
Pneumatic Artificial Muscle ◽  
Pneumatic Muscle

In this work a novel pneumatic artificial muscle is fabricated using golden muga silk and silicon rubber. It is assumed that the muscle force is a quadratic function of pressure. Here a single degree of freedom system is considered where a mass is supported by a spring-damper-and pneumatically actuated muscle. While the spring-mass damper is a passive system, the addition of pneumatic muscle makes the system active. The dynamic analysis of this system is carried out by developing the equation of motion which contains multi-frequency excitations with both forced and parametric excitations. Using method of multiple scales the reduced equations are developed for simple and principal parametric resonance conditions. The time response obtained using method of multiple scales have been compared with those obtained by solving the original equation of motion numerically. Using both time response and phase portraits, variation of few systems parameters have been carried out. This work may find application in developing wearable device and robotic device for rehabilitation purpose.

Controlling Nonlinear Dynamics in a Two-Well Impact System.

1998 ◽  
Vol 08 (12) ◽  
pp. 2409-2424 ◽  
Author(s):  
Stefano Lenci ◽  
Giuseppe Rega
Keyword(s):  
Nonlinear Dynamics ◽  
High Gain ◽  
Harmonic Excitation ◽  
Phase Portraits ◽  
System Response ◽  
Control Procedure ◽  
Combined Use ◽  
Controlled Potential ◽  
And Control ◽  
Amplitude Level

To exploit all potentialities of the optimal control procedure, the analysis initiated in Part I focuses on the system response under one-side control, an excitation which furnishes high gain though, roughly, controlling only one part of the phase space. Many bifurcational and control items related to the unsymmetric and pulsed nature of the excitation are deeply investigated. A nonclassical kind of homoclinic bifurcation is identified and it is discussed how it may lead to major regularity. The system response is very rich, and the main local and global phenomena of the dynamics are analyzed in detail through combined use of bifurcation diagrams and attractor-basin phase portraits. Both the confinement of steady dynamics in the controlled potential well and their successive transition from confined to scattered are studied, and it is discussed how they are obtained through comparison with the case of harmonic excitation. It is shown that the two investigated optimal excitations permit to increase the amplitude level for confined to scattered dynamics and to regularize the steady dynamics, although in a different manner. The analysis shows the effectiveness — in "average" sense — of the proposed method for controlling nonlinear dynamics.

A Pneumatic Artificial Muscle Bionic Kangaroo Leg Suspension

2019 ◽  
Vol 12 (4) ◽  
pp. 357-366
Author(s):  
Yong Song ◽  
Shichuang Liu ◽  
Jiangxuan Che ◽  
Jinyi Lian ◽  
Zhanlong Li ◽  
...  
Keyword(s):  
Strong Shock ◽  
Artificial Muscle ◽  
Suspension System ◽  
Vehicle Body ◽  
Vehicle Suspension ◽  
Pneumatic Artificial Muscle ◽  
Advantages And Disadvantages ◽  
Road Excitation ◽  
Vehicle Suspension System ◽  
Suspension Structure

Background: Vehicles generally travel on different road conditions, and withstand strong shock and vibration. In order to reduce or isolate the strong shock and vibration, it is necessary to propose and develop a high-performance vehicle suspension system. Objective: This study aims to report a pneumatic artificial muscle bionic kangaroo leg suspension to improve the comfort performance of vehicle suspension system. Methods: In summarizing the existing vehicle suspension systems and analyzing their advantages and disadvantages, this paper introduces a new patent of vehicle suspension system based on the excellent damping and buffering performance of kangaroo leg, A Pneumatic Artificial Muscle Bionic Kangaroo Leg Suspension. According to the biomimetic principle, the pneumatic artificial muscles bionic kangaroo leg suspension with equal bone ratio is constructed on the basis of the kangaroo leg crural index, and two working modes (passive and active modes) are designed for the suspension. Moreover, the working principle of the suspension system is introduced, and the rod system equations for the suspension structure are built up. The characteristic simulation model of this bionic suspension is established in Adams, and the vertical performance is analysed. Results: It is found that the largest deformation happens in the bionic heel spring and the largest angle change occurs in the bionic ankle joint under impulse road excitation, which is similar to the dynamic characteristics of kangaroo leg. Furthermore, the dynamic displacement and the acceleration of the vehicle body are both sharply reduced. Conclusion: The simulation results show that the comfort performance of this bionic suspension is excellent under the impulse road excitation, which indicates the bionic suspension structure is feasible and reasonable to be applied to vehicle suspensions.

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