An RC filter for hydraulic switching control with a transmission line between valves and actuator

Author(s):  
Rainer Haas ◽  
Evgeny Lukachev ◽  
Rudolf Scheidl

Hydraulic switching control with fast switching valves may excite unacceptable hydraulic and mechanical oscillations. Particularly if transmission lines are used, which have many oscillation modes, the avoidance of resonances by a proper timing of the switching pulses is hardly feasible. Then, passive filters may be a good solution. A simple RC filter applied to a cylinder drive with a transmission line to the switching valves is investigated by a transfer function analysis, numerical methods, and experiments. Properties of the dynamic behaviour are elucidated by approximate relations derived from the transfer function by asymptotic methods. A simple dimensioning rule recommends sizing the filter resistance close to the hydraulic impedance of the transmission line. The capacitance’s sizing is a trade off between a potential reduction of the resonance peak due to the cylinder natural frequency and a softness of the hydraulic drive system.

2020 ◽  
Vol 10 (15) ◽  
pp. 5257
Author(s):  
Nathan Berwick ◽  
Hyunkook Lee

This study examined whether the spatial unmasking effect operates on speech reception thresholds (SRTs) in the median plane. SRTs were measured using an adaptive staircase procedure, with target speech sentences and speech-shaped noise maskers presented via loudspeakers at −30°, 0°, 30°, 60° and 90°. Results indicated a significant median plane spatial unmasking effect, with the largest SRT gain obtained for the −30° elevation of the masker. Head-related transfer function analysis suggests that the result is associated with the energy weighting of the ear-input signal of the masker at upper-mid frequencies relative to the maskee.


2011 ◽  
Vol 59 (7) ◽  
pp. 1696-1708 ◽  
Author(s):  
Huang Wang ◽  
Lingling Sun ◽  
Jun Liu ◽  
Huanhuan Zou ◽  
Zhiping Yu ◽  
...  

2015 ◽  
Vol 79 (3) ◽  
pp. 453-459 ◽  
Author(s):  
Zachary A. Vesoulis ◽  
Steve M. Liao ◽  
Shamik B. Trivedi ◽  
Nathalie El Ters ◽  
Amit M. Mathur

Author(s):  
Debao Li ◽  
Fangze Li ◽  
Peiming Xu

Abstract This paper deals with the dynamic modification simulation of the structure. The expressions of sensitivity analysis of the system with non-proportional damping and proportional damping are derived at first. As for the reanalysis of modified structure, here we deal with the system to which the modification do not cause any change of the degrees of freedom. Transfer function analysis method and the method of twice coordinate transformation are expounded. As a successful example, the modification simulation of the frame of a dump truck is explained.


Geosphere ◽  
2020 ◽  
Author(s):  
Alan R. Nelson ◽  
Andrea D. Hawkes ◽  
Yuki Sawai ◽  
Ben P. Horton ◽  
Rob C. Witter ◽  
...  

Lithology and microfossil biostratigraphy beneath the marshes of a central Oregon estuary limit geophysical models of Cascadia megathrust rupture during successive earthquakes by ruling out >0.5 m of coseismic coastal subsidence for the past 2000 yr. Although the stratigraphy in cores and outcrops includes as many as 12 peat-mud contacts, like those commonly inferred to record sub­sidence during megathrust earthquakes, mapping, qualitative diatom analysis, foraminiferal transfer function analysis, and 14C dating of the contacts failed to confirm that any contacts formed through subsidence during great earthquakes. Based on the youngest peat-mud contact’s distinctness, >400 m distribution, ∼0.6 m depth, and overlying probable tsunami deposit, we attribute it to the great 1700 CE Cascadia earthquake and(or) its accompanying tsunami. Minimal changes in diatom assemblages from below the contact to above its probable tsunami deposit suggest that the lower of several foraminiferal transfer function reconstructions of coseismic subsidence across the contact (0.1–0.5 m) is most accurate. The more limited stratigraphic extent and minimal changes in lithology, foraminifera, and(or) diatom assemblages across the other 11 peat-mud contacts are insufficient to distinguish them from contacts formed through small, gradual, or localized changes in tide levels during river floods, storm surges, and gradual sea-level rise. Although no data preclude any contacts from being synchronous with a megathrust earthquake, the evidence is equally consistent with all contacts recording relative sea-level changes below the ∼0.5 m detection threshold for distinguishing coseismic from nonseismic changes.


2004 ◽  
Vol 43 (35) ◽  
pp. 6413 ◽  
Author(s):  
Jer Wang Chan ◽  
James Paul Owain Evans ◽  
Yen San Yong ◽  
Andrew Monteith

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