Design of High-Order Type-II Delay-Locked Loops With a Fast-Settling-Zero-Overshoot Step Response and Large Jitter-Rejection Capabilities

2018 ◽  
Vol 65 (6) ◽  
pp. 1805-1818
Author(s):  
Yan Li ◽  
Gordon W. Roberts
Keyword(s):  
Order Type ◽  
High Order ◽  
Step Response ◽  
Type Ii ◽  
Delay Locked Loops ◽  
Fast Settling

Syntheses of Dimeric Securinega Alkaloids

Synlett ◽  
2017 ◽  
Vol 28 (18) ◽  
pp. 2353-2359 ◽  
Author(s):  
Sunkyu Han ◽  
Sangbin Jeon ◽  
Joonoh Park
Keyword(s):  
Natural Products ◽  
High Order ◽  
Molecular Structures ◽  
Type I ◽  
Type Ii ◽  
Type Iii ◽  
Organic Community

The isolation of flueggenines A and B by Yue and co-workers in 2006 has triggered a burst of isolation reports of dimeric and oligomeric securinega alkaloid natural products. The compelling molecular structures of these compounds with various modes of connection between monomeric securinega units have posed intriguing challenges to the synthetic organic community. Herein, we have categorized high-order securinega alkaloids based on their biosynthetic mode of dimerization or oligomerization. We then have compiled all reported syntheses of dimeric securinega alkaloids based on our classification.1 Introduction2 Categorization of High-Order Securinega Alkaloid Natural Products3 Syntheses of Type I Dimeric Securinega Alkaloids4 Syntheses of Type II Dimeric Securinega Alkaloids5 Synthesis of Type III Dimeric Securinega Alkaloid6 Conclusion

A High Order, Lumped Parameter, Jet Dynamic Model for the Frequency Response of Laminar Proportional Amplifiers

1981 ◽  
Vol 103 (4) ◽  
pp. 317-323
Author(s):  
T. M. Drzewiecki
Keyword(s):  
Frequency Response ◽  
Dynamic Model ◽  
Low Frequency ◽  
Electrical Circuit ◽  
High Order ◽  
Step Response ◽  
Average Particle ◽  
Laplace Domain ◽  
Lumped Parameter ◽  
Good Agreement

This paper presents a high-order, lumped parameter, jet-dynamic model for laminar proportional amplifiers (LPA’s). The governing equations for the lumped-parameter representation of the flow regimes found in the input of an LPA are derived in the Laplace domain, and an equivalent electrical circuit is obtained. The input governs the overall response of the LPA and may be modeled in its simplest form by five reactive components. The transmission of the signal from input to output is delayed by a transport time (determined by observation of flow visualization of a step response) equal to twice the average particle transit time. A pressure difference is then developed at the splitter that is proportional to the loading and the vent conditions. This signal is acoustically fed back to the control region of the jet, augmenting jet deflection when in phase. The vent inductance is found to have a significant influence on the low-frequency gain. Resonant regions determined by this model correspond closely to edgetone eigenfrequencies reported in the literature. Experimental data have shown good agreement with theory for the amplitude frequency response of LPA’s and excellent agreement for the phase shift. An engineering guide developed for the bandpass characteristics of LPA’s indicates that operating bandwidths of up to 14 kHz can be expected for amplifiers with a nozzle width of 0.25 mm, and ultrasonic operation appears feasible with devices having nozzle widths as large as 0.1 mm.

scholarly journals Angle Tracking Observer with Improved Accuracy for Resolver-to-Digital Conversion

Symmetry ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1347 ◽  
Author(s):  
Haoye Qin ◽  
Zhong Wu
Keyword(s):  
Phase Error ◽  
Angular Position ◽  
Position Estimation ◽  
High Order ◽  
Phase Detector ◽  
Type Ii ◽  
Digital Conversion ◽  
Estimation Errors ◽  
Angle Tracking ◽  
Acceleration Signals

A resolver is an absolute shaft sensor which outputs pair signals with ortho-symmetric amplitudes. Ideally, they are sinusoidal and cosinusoidal functions of the shaft angle. In order to demodulate angular position and velocity from resolver signals, resolver-to-digital conversion (RDC) is necessary. In software-based RDC, most algorithms mainly employ a phase-locked loop (PLL)-based angle tracking observer (ATO) to form a type-II system. PLL can track the detected angle by regulating the phase error from the phase detector which depends on the feature of orthogonal symmetry in the resolver outputs. However, a type-II system will result in either steady-state errors or cumulative errors in the estimation of angular position with constant accelerations. Although type-III ATOs can suppress these errors, they are still vulnerable to high-order acceleration signals. In this paper, an improved PLL-based ATO with a compensation model is proposed. By using dynamic compensation, the proposed ATO becomes a type-IV system and can reduce position estimation errors for high-order acceleration signals. In addition, the parameters of ATO can be tuned according to the bandwidth, noise level and capability of error suppression. Simulation and experimental results demonstrate the effectiveness of the proposed method.

The Approach for Analyzing Motion Mode of High-Order Control Systems

2014 ◽  
Vol 596 ◽  
pp. 594-597
Author(s):  
Sheng Guo Zhang ◽  
Kai Wang ◽  
Xiao Ping Dang
Keyword(s):  
Control System ◽  
Modal Analysis ◽  
Control Systems ◽  
High Order ◽  
Step Response ◽  
Space Theory ◽  
Analysis Method ◽  
Inverse Laplace Transformation ◽  
State Space Theory ◽  
Motion Mode

This paper aims at exploring the modal analysis approach of a motion control system. Based on the inverse Laplace transformation, the step response of a control system is derived. Then this response is associated with the modal analyses in state space theory. And then the motion mode of a control system is analyzed with the modal analysis method. Application example indicates that this approach can be used to analyze the high-order control system successfully. This facilitates the motion mode analyses of high-order control system very much.

scholarly journals Beetroot juice supplementation speeds O2uptake kinetics and improves exercise tolerance during severe-intensity exercise initiated from an elevated metabolic rate

2013 ◽  
Vol 305 (12) ◽  
pp. R1441-R1450 ◽  
Author(s):  
Brynmor C. Breese ◽  
Melitta A. McNarry ◽  
Simon Marwood ◽  
Jamie R. Blackwell ◽  
Stephen J. Bailey ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
Exercise Tolerance ◽  
Near Infrared ◽  
Order Type ◽  
Moderate Intensity ◽  
Type Ii ◽  
Beetroot Juice ◽  
Moderate Intensity Exercise ◽  
Double Blind ◽  
Severe Intensity

Recent research has suggested that dietary nitrate (NO3−) supplementation might alter the physiological responses to exercise via specific effects on type II muscle. Severe-intensity exercise initiated from an elevated metabolic rate would be expected to enhance the proportional activation of higher-order (type II) muscle fibers. The purpose of this study was, therefore, to test the hypothesis that, compared with placebo (PL), NO3−-rich beetroot juice (BR) supplementation would speed the phase II V̇o2kinetics (τp) and enhance exercise tolerance during severe-intensity exercise initiated from a baseline of moderate-intensity exercise. Nine healthy, physically active subjects were assigned in a randomized, double-blind, crossover design to receive BR (140 ml/day, containing ∼8 mmol of NO3−) and PL (140 ml/day, containing ∼0.003 mmol of NO3−) for 6 days. On days 4, 5, and 6 of the supplementation periods, subjects completed a double-step exercise protocol that included transitions from unloaded to moderate-intensity exercise (U→M) followed immediately by moderate to severe-intensity exercise (M→S). Compared with PL, BR elevated resting plasma nitrite concentration (PL: 65 ± 32 vs. BR: 348 ± 170 nM, P < 0.01) and reduced the V̇o2τpin M→S (PL: 46 ± 13 vs. BR: 36 ± 10 s, P < 0.05) but not U→M (PL: 25 ± 4 vs. BR: 27 ± 6 s, P > 0.05). During M→S exercise, the faster V̇o2kinetics coincided with faster near-infrared spectroscopy-derived muscle [deoxyhemoglobin] kinetics (τ; PL: 20 ± 9 vs. BR: 10 ± 3 s, P < 0.05) and a 22% greater time-to-task failure (PL: 521 ± 158 vs. BR: 635 ± 258 s, P < 0.05). Dietary supplementation with NO3−-rich BR juice speeds V̇o2kinetics and enhances exercise tolerance during severe-intensity exercise when initiated from an elevated metabolic rate.

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