Real-Time Analog-Digital Computation

SIMULATION ◽  
1963 ◽  
Vol 1 (1) ◽  
pp. R-29-R-39
Author(s):  
Mark E. Connelly
Keyword(s):  
Real Time ◽  
Digital Computer ◽  
High Speed ◽  
Dynamic Range ◽  
Digital Computation ◽  
Function Generation ◽  
Hybrid Computer ◽  
Complex Nonlinear Systems ◽  
Hybrid Configuration ◽  
Computing Speed

The relative advantages of analog and digital tech niques in simulating complex, nonlinear systems in real-time are discussed. A hybrid configuration is suggested consisting of a basic digital computer and peripheral, high-speed analog elements used on a time-shared basis under the control of the digital program. Programs for function generation and for the solution of the aircraft roll equation are presented to illustrate the operation of the hybrid computer and the significant increase in the effective computing speed of the digital computer that results from the incorporation of peripheral analog elements. Further gains can be made by tailoring the order code and logic of the digital computer to the specific prob lem class of interest. The hypothesis is presented that a hybrid computer is technically feasible today that would be competitive with analog techniques on the basis of both cost and the ability to simulate natural aircraft frequencies in real-time. Moreover, such a computer would offer substantial advantages with respect to accuracy, dynamic range, flexibility, size, power consumption, and reliability.

scholarly journals Compressed Sensing of Scanning Transmission Electron Microscopy (STEM) With Nonrectangular Scans

2018 ◽  
Vol 24 (6) ◽  
pp. 623-633 ◽  
Author(s):  
Xin Li ◽  
Ondrej Dyck ◽  
Sergei V. Kalinin ◽  
Stephen Jesse
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Real Time ◽  
Scanning Transmission Electron Microscopy ◽  
High Speed ◽  
Dynamic Range ◽  
Extended Defects ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission

AbstractScanning transmission electron microscopy (STEM) has become the main stay for materials characterization on atomic level, with applications ranging from visualization of localized and extended defects to mapping order parameter fields. In recent years, attention has focused on the potential of STEM to explore beam induced chemical processes and especially manipulating atomic motion, enabling atom-by-atom fabrication. These applications, as well as traditional imaging of beam sensitive materials, necessitate increasing the dynamic range of STEM in imaging and manipulation modes, and increasing the absolute scanning speed which can be achieved by combining sparse sensing methods with nonrectangular scanning trajectories. Here we have developed a general method for real-time reconstruction of sparsely sampled images from high-speed, noninvasive and diverse scanning pathways, including spiral scan and Lissajous scan. This approach is demonstrated on both the synthetic data and experimental STEM data on the beam sensitive material graphene. This work opens the door for comprehensive investigation and optimal design of dose efficient scanning strategies and real-time adaptive inference and control of e-beam induced atomic fabrication.

A demonstration hybrid computer for real-time flight simulation

SIMULATION ◽  
1965 ◽  
Vol 5 (3) ◽  
pp. 191-200 ◽  
Author(s):  
Mark E. Connelly
Keyword(s):  
Real Time ◽  
Digital Computer ◽  
High Performance ◽  
Nonlinear Effects ◽  
Flight Simulation ◽  
Solution Rate ◽  
Engine Simulation ◽  
Digital Reference ◽  
Complex Simulation ◽  
Hybrid Configuration

A hybrid, real-time simulation facility has been de signed, constructed, and demonstrated, using as a test vehicle the complete aerodynamic and engine equations for a high-performance military aircraft. The analog-digital configuration employs peripheral analog equipment to represent a linear, skeleton version of the aircraft and the PDP-1 digital com puter to carry out engine simulation, decision man agement, and corrections for nonlinear effects. To provide an all-digital reference against which the hybrid simulation could be compared, the air craft model was also simulated in real-time on the PDP-1 alone. It was found that the solution rate of 20 per second employed in the all-digital study could be reduced substantially without deleterious effects when the hybrid configuration was used. Such a re duction demonstrates that supplementing a digital computer by relatively inexpensive analog peripheral equipment greatly increases the real-time capacity of the digital computer in complex simulation appli cations. Moreover, because a number of key variables are computed continuously in the analog domain, the introduction of analog equipment results in a net decrease in the complexity of the interface.

Application Research on Precision Detection of Small Gear with Composite Edge Detection Method

2013 ◽  
Vol 333-335 ◽  
pp. 1123-1128
Author(s):  
Xin Luo ◽  
Li Ming Wu ◽  
De Zhi Zeng
Keyword(s):  
Edge Detection ◽  
Real Time ◽  
High Speed ◽  
Dynamic Range ◽  
Detection Method ◽  
Detection System ◽  
Structural Characteristics ◽  
Low Cost ◽  
Edge Image ◽  
Edge Detection Method

Vision-based measurement method can be widely used for a variety of real-time and online precision measurements, and particularly well suited for dynamic real-time precision measurement of geometry parameters of the part, which has advantages of non-contact, high-speed, big dynamic range, rich amount of information, and relatively low cost. After the study of vision-based online detection system of small gear, we propose a composite subpixel edge detection method, which combines the four-way weighted differential algorithm based on the classic Sobel operator and OFMM (Orthogonal Fourier-Mellin Moment), aiming at achieving the precision location of the subpixel edge firstly. And then detect tooth profile defects rapidly through scanning circularly the edge image, according to the structural characteristics of gears. The theoretical analysis and experimental results show that the detection method has so high accuracy and speed that it can meet the industrial online tests requirements.

Real-time simulation of a helicopter rotor on an analog computer

SIMULATION ◽  
1970 ◽  
Vol 14 (5) ◽  
pp. 231-237
Author(s):  
Milton Schramm
Keyword(s):  
Real Time ◽  
Hybrid Systems ◽  
High Speed ◽  
Initial Conditions ◽  
Analog Computer ◽  
Helicopter Rotor ◽  
Real Time Simulation ◽  
Time Simulation ◽  
Hybrid Computer ◽  
Lift And Drag

An accurate real-time simulation of a helicopter rotor can be achieved on a high-speed analog computer. By using repetitive operation and integrating along each blade every 2.5 milliseconds, the double integration required to determine rotor torque, thrust, moment, and rearward and sideward rotor forces is accomplished. The lift and drag coefficients are continuously calculated at all points along the blade. The same analog equipment used to calculate quantities for one blade is used for other blades by chang ing appropriate initial conditions. This analysis provides a transient rotor solution in which integration out the blade is accomplished every five rotor azimuth degrees. One console of a Hybrid Systems, Inc., SS-100 Analog/Hybrid Computer is used for the rotor solution.

A High-Speed Vision System with Multithread Automatic Exposure Control for High-Dynamic-Range Imaging

2018 ◽  
Vol 30 (1) ◽  
pp. 117-127
Author(s):  
Xianwu Jiang ◽  
Qingyi Gu ◽  
Tadayoshi Aoyama ◽  
Takeshi Takaki ◽  
Idaku Ishii ◽  
...  
Keyword(s):  
Real Time ◽  
High Speed ◽  
Dynamic Range ◽  
Vision System ◽  
Dynamic Change ◽  
Large Change ◽  
High Dynamic Range ◽  
Frame Rate ◽  
Processing Unit ◽  
High Dynamic

In this study, we develop a real-time high-frame-rate vision system with frame-by-frame automatic exposure (AE) control that can simultaneously synthesize multiple images with different exposure times into a high-dynamic-range (HDR) image for scenarios with dynamic change in illumination. By accelerating the video capture and processing for time-division multithread AE control at the millisecond level, the proposed system can virtually function as multiple AE cameras with different exposure times. This system can capture color HDR images of 512 × 512 pixels in real time at 500 fps by synthesizing four 8-bit color images with different exposure times at consecutive frames, captured at an interval of 2 ms, with pixel-level parallel processing accelerated by a GPU (Graphic Processing Unit) board. Several experimental results for scenarios with a large change in illumination are demonstrated to confirm the performance of the proposed system for real-time HDR imaging.

High speed interferometric device for real-time correction of aero-optic effects

1995 ◽  
Author(s):  
Rod Clark ◽  
John Karpinsky ◽  
Gregg Borek ◽  
Eric Johnson
Keyword(s):  
Real Time ◽  
High Speed ◽  
Time Correction

Electrical Probing and Surface Imaging of Deep Sub-Micron Integrated Circuits

1999 ◽  
Author(s):  
Kenneth Krieg ◽  
Richard Qi ◽  
Douglas Thomson ◽  
Greg Bridges
Keyword(s):  
High Resolution ◽  
Integrated Circuits ◽  
Real Time ◽  
High Speed ◽  
Time Signal ◽  
Surface Imaging ◽  
Atomic Force ◽  
Submicron Structures ◽  
High Resolution Images ◽  
Capacitive Loading

Abstract A contact probing system for surface imaging and real-time signal measurement of deep sub-micron integrated circuits is discussed. The probe fits on a standard probe-station and utilizes a conductive atomic force microscope tip to rapidly measure the surface topography and acquire real-time highfrequency signals from features as small as 0.18 micron. The micromachined probe structure minimizes parasitic coupling and the probe achieves a bandwidth greater than 3 GHz, with a capacitive loading of less than 120 fF. High-resolution images of submicron structures and waveforms acquired from high-speed devices are presented.

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