Dead-time free pixel readout architecture for ATLAS front-end IC

1999 ◽  
Vol 46 (3) ◽  
pp. 166-170 ◽  
Author(s):  
K. Einsweiler ◽  
A. Joshi ◽  
S. Kleinfelder ◽  
L. Luo ◽  
R. Marchesini ◽  
...  
Keyword(s):  
2017 ◽  
Vol 33 (6) ◽  
pp. 757-767 ◽  
Author(s):  
Chang-Joo Lee ◽  
Hak-Jin Kim ◽  
Jong-Woo Ha ◽  
Bong-Jin Cho ◽  
Duk-Soo Choi

Abstract. There has been a growing trend toward electronic control of hydraulic systems in agricultural machinery to improve operator comfort. Rapid advances in information and communications technology and the expansion of agricultural attachments have led to the introduction of control systems following the ISOBUS standard. Feedback control of a front-end loader (FEL) using electro-hydraulic proportional valves and sensors allows automatic activation of the boom and bucket cylinders and repetitive operational sequences of FEL functions. The mechanical self-leveling systems commonly used to prevent rollback have a limited range of operation and provide overcompensation beyond that range, therefore requiring considerable driver attention when operating the FEL. This article describes the development and evaluation of an ISOBUS-networked electronic self-leveling system that uses three electronic control units (ECUs), i.e., loader, joystick, and virtual terminal ECUs, to automatically adjust the orientation of the loader bucket with respect to the ground based on real-time measurements of bucket angle and angular velocity. Key improvements to the system, compared to a previous study that developed a proportional and integral (PI)–based self-leveling controller include the addition of a velocity feedback element and a dead-time effect computation to the control loop. An embedded electronic controller was implemented on agricultural tractors to test its ability to maintain the desired bucket angle regardless of varying ground slopes or the lifting or lowering motion of the boom. In laboratory testing with a FEL simulator, the use of the velocity feedback loop enabled the bucket angles to reach reference angles of +20°, showing reductions in rise times from 0.75 to 0.51 s and from 0.84 to 0.39 s on ascending and descending slopes, respectively, compared to the PI-based self-leveling algorithm. At a traveling velocity of 2.5 km/h, there was little change in bucket angle, with an almost constant level of <1°. However, at a velocity of 7.5 km/h, inflection points on the paved road caused relatively large deviations from the reference angle ranging from 3° to 5°, thus requiring the use of a look-ahead method to predict sudden changes in slope using a LIDAR sensor that can characterize the ground surface. In an outdoor bench test using a joystick to raise and lower the boom of a FEL, the self-leveling algorithm allowed the bucket angle to be maintained at the desired level, with RMSEs of 2.1±0.65° and 3.4±0.81° in the raising and lowering modes, respectively; thus, it could be implemented in an electronic self-leveling system for a FEL, which could then be employed in an ISOBUS-networked tractor offering the potential to eliminate the possibility of load rollback. Keywords: Dead-time computation, Electro-hydraulic proportional valve, Electronic control unit, Front-end loader, ISOBUS, Self-leveling, Velocity feedback.


2016 ◽  
Vol 11 (04) ◽  
pp. P04010-P04010
Author(s):  
L. Anderlini ◽  
M. Anelli ◽  
F. Archilli ◽  
G. Auriemma ◽  
W. Baldini ◽  
...  

2018 ◽  
Author(s):  
Davide Braga ◽  
Luigi Gaioni ◽  
David Charles Christian ◽  
Grzegorz Deptuch ◽  
Farah Fahim ◽  
...  

Author(s):  
JR Fryer ◽  
Z Huang ◽  
D Stirling ◽  
G. Webb

Platinum dispersed on γ-alumina is used as a reforming catalyst to convert linear hydrocarbons to cyclic aromatic products. To improve selectivity and lifetime of the catalyst, other elements are included, and we have studied the distributions of Pt/Re, and Pt/Sn, bimetallic systems on the support both before and after use in octane reforming. Often, one or both of the components are not resolvable by HREM or microanalysis as individual particles because of small size and lack of contrast on the alumina, and divergent beam microanalysis has been used to establish the presence and relationship between the two elements.In the majority of catalysts the platinum is in the form of small panicles, some of which are large enough to be resolvable in the microscope. The ABT002B microscope with Link windowless Pentafet detector, used in this work, was able to obtain a resolvable signal from particles of 2nm diameter upwards. When the beam was concentrated on to such a particle the signal was at a maximum, and as the beam diameter was diverged - at the same total beam intensity and dead time - the signal decreased as shown in Figure 1.


Author(s):  
John J. Friel

Committee E-04 on Metallography of the American Society for Testing and Materials (ASTM) conducted an interlaboratory round robin test program on quantitative energy dispersive spectroscopy (EDS). The test program was designed to produce data on which to base a precision and bias statement for quantitative analysis by EDS. Nine laboratories were sent specimens of two well characterized materials, a type 308 stainless steel, and a complex mechanical alloy from Inco Alloys International, Inconel® MA 6000. The stainless steel was chosen as an example of a straightforward analysis with no special problems. The mechanical alloy was selected because elements were present in a wide range of concentrations; K, L, and M lines were involved; and Ta was severely overlapped with W. The test aimed to establish limits of precision that could be routinely achieved by capable laboratories operating under real world conditions. The participants were first allowed to use their own best procedures, but later were instructed to repeat the analysis using specified conditions: 20 kV accelerating voltage, 200s live time, ∼25% dead time and ∼40° takeoff angle. They were also asked to run a standardless analysis.


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