Scaling laws for frequency domain controllers of dynamically equivalent single flexible link manipulators

2002 ◽  
Author(s):  
M. Ghanekar ◽  
D.W.L. Wang ◽  
G.R. Heppler
Keyword(s):  
Frequency Domain ◽  
Scaling Laws ◽  
Flexible Link

Application of an Advanced Frequency Domain Identification Method for Modelling of Flexible-Link Manipulators

2003 ◽  
Author(s):  
G. M. Y. Lai ◽  
K. Ziaei ◽  
D. W. L. Wang ◽  
G. R. Heppler
Keyword(s):  
System Identification ◽  
Transfer Function ◽  
Frequency Domain ◽  
Contact Force ◽  
Strain Gauges ◽  
Flexible Link ◽  
Domain Identification ◽  
Frequency Responses ◽  
System Frequency ◽  
Identification Tool

This paper investigates the Comprehensive Identification from FrEquency Responses (CIFER) technique as a system identification tool for the Single Flexible Link (SFL) manipulator system. Frequency responses are identified for both the constrained and unconstrained motions. For the constrained case, two sets of frequency responses are identified based on actual contact force and an approximated contact force obtained through strain gauges readings. Identification results from CIFER® are compared to those from the Empirical Transfer Function Estimate (ETFE).

scholarly journals A revisit of the tonal noise of small rotors

2020 ◽  
Vol 476 (2244) ◽  
pp. 20200491
Author(s):  
Siyang Zhong ◽  
Peng Zhou ◽  
Ryu Fattah ◽  
Xin Zhang
Keyword(s):  
Frequency Domain ◽  
Scaling Laws ◽  
Unsteady Motion ◽  
Flow Speed ◽  
Quadratic Functions ◽  
Design Parameters ◽  
Frequency Domain Method ◽  
Mean Flow ◽  
Tonal Noise ◽  
Blade Number

In this study, asymptotic analysis of the frequency-domain formulation to compute the tonal noise of the small rotors in the now ubiquitously multi-rotor powered drones is conducted. Simple scaling laws are proposed to evaluate the impacts of the influential parameters such as blade number, flow speed, rotation speed, unsteady motion, thrust and observer angle on the tonal noise. The rate of noise increment with thrust (or rotational speed) is determined by orders of blade passing frequency harmonics and the unsteady motion. The axial mean flow influence can be approximated by quadratic functions. At given thrust, the sound decreases rapidly with the radius and blade number as the surface pressure becomes less intensive. The higher tonal harmonics are significantly increased if unsteady motions, although of small-amplitude, are existed, as indicated by the defined sensitivity function, emphasizing that the unsteady motions should be avoided for quiet rotor designs. The scaling laws are examined by comparing with the full computations of the rotor noise using the frequency-domain method, the implementation of which has been validated by comparing with experiments. Good data collapse is obtained when the proposed scaling laws, which highlights the dominant influence of the design parameters, are incorporated.

Siphon Flows in Stratified Coronal Loops

1994 ◽  
Vol 144 ◽  
pp. 185-187
Author(s):  
S. Orlando ◽  
G. Peres ◽  
S. Serio
Keyword(s):  
Heat Flux ◽  
Scaling Laws ◽  
Flow Model ◽  
Supersonic Flows ◽  
Coronal Loops ◽  
Characteristic Parameters

AbstractWe have developed a detailed siphon flow model for coronal loops. We find scaling laws relating the characteristic parameters of the loop, explore systematically the space of solutions and show that supersonic flows are impossible for realistic values of heat flux at the base of the upflowing leg.

Correction to "The analysis of slug tests in the frequency domain" (WRR 25(11), pp. 2388-2396

1990 ◽  
Vol 26 (8) ◽  
pp. 1863-1863
Author(s):  
Paul Marschall ◽  
Baldur Barczewski
Keyword(s):  
Frequency Domain ◽  
Slug Tests
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