Tracking the resonance frequency of a series RLC circuit using a phase locked loop

Author(s):  
C. Gokcek
Author(s):  
Matthew Clark ◽  
Z. C. Feng

This paper explores dynamically deriving the mechanical properties of a substrate. A method is presented in which a phase locked loop (PLL) is used to find the resonance frequency of a mechanical model consisting of an oscillating probe and a material substrate. This is done by first presenting an accurate PLL which is stable for nonlinear systems. The relationship between the system frequency and the stiffness of the material substrate is derived theoretically. The stiffness of the substrate is obtained by combining the theoretical result and the converging resonance frequency from PLL.


2014 ◽  
Vol 5 ◽  
pp. 278-288 ◽  
Author(s):  
Gheorghe Stan ◽  
Santiago D Solares

The resonance frequency, amplitude, and phase response of the first two eigenmodes of two contact-resonance atomic force microscopy (CR-AFM) configurations, which differ in the method used to excite the system (cantilever base vs sample excitation), are analyzed in this work. Similarities and differences in the observables of the cantilever dynamics, as well as the different effect of the tip–sample contact properties on those observables in each configuration are discussed. Finally, the expected accuracy of CR-AFM using phase-locked loop detection is investigated and quantification of the typical errors incurred during measurements is provided.


2020 ◽  
Vol 14 (4) ◽  
pp. 7396-7404
Author(s):  
Abdul Malek Abdul Wahab ◽  
Emiliano Rustighi ◽  
Zainudin A.

Various complex shapes of dielectric electro-active polymer (DEAP) actuator have been promoted for several types of applications. In this study, the actuation and mechanical dynamics characteristics of a new core free flat DEAP soft actuator were investigated. This actuator was developed by Danfoss PolyPower. DC voltage of up to 2000 V was supplied for identifying the actuation characteristics of the actuator and compare with the existing formula. The operational frequency of the actuator was determined by dynamic testing. Then, the soft actuator has been modelled as a uniform bar rigidly fixed at one end and attached to mass at another end. Results from the theoretical model were compared with the experimental results. It was found that the deformation of the current actuator was quadratic proportional to the voltage supplied. It was found that experimental results and theory were not in good agreement for low and high voltage with average percentage error are 104% and 20.7%, respectively. The resonance frequency of the actuator was near 14 Hz. Mass of load added, inhomogeneity and initial tension significantly affected the resonance frequency of the soft actuator. The experimental results were consistent with the theoretical model at zero load. However, due to inhomogeneity, the frequency response function’s plot underlines a poor prediction where the theoretical calculation was far from experimental results as values of load increasing with the average percentage error 15.7%. Hence, it shows the proposed analytical procedure not suitable to provide accurate natural frequency for the DEAP soft actuator.


2013 ◽  
Vol 133 (4) ◽  
pp. 388-394 ◽  
Author(s):  
Akihiro Ohori ◽  
Nobuyuki Hattori ◽  
Tsuyoshi Funaki

Sign in / Sign up

Export Citation Format

Share Document