Modeling and analysis of responsive space launch system based on timed colored Petri NeT

Responsive space launch is currently developing rapidly and has application cases in many fields, with advantages such as fast response speed and flexible networking. Aiming at the efficiency evaluation of responsive space launch system, this article first summarizes the typical process of fast space launch, and then gives a hierarchical model of a space fast launch system based on timed colored Petri nets, including top-level model, demand model, command decision model, launch Model, measurement and control model, and finally use CPN Tools to simulate and verify the model, analyze the basic characteristics of the model and the performance of the system, and provide data support and theoretical basis for the optimization of the fast space launch system.

Download Full-text

Design and Implement of Intelligent Monitoring System Driven by Ultrasonic Motor

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.765-767.2199 ◽

2013 ◽

Vol 765-767 ◽

pp. 2199-2202

Author(s):

Hao Yin ◽

Hua Feng Li

Keyword(s):

Tracking System ◽

Response Speed ◽

Video Camera ◽

Fast Response ◽

Ultrasonic Motor ◽

Quick Response ◽

Tracking Accuracy ◽

Intelligent Monitoring ◽

Ultrasonic Motors ◽

And Control

A visual tracking system based on ultrasonic motors is designed in view of shortcoming of traditional video surveillance system, which has a large volume, complicated structure. The pan-tilt can rotate in horizontal and vertical directions by using two ultrasonic motors served as the driving units. The image from video camera is processed and the target is identified and real-time tracked by rotating the pan-tilt which is controlled by ultrasonic motor. Compared with electromagnetic motor, the ultrasonic motor has advantages of high torque at low speed, quick response, high precision and self-locked, which makes the structure simpler and control more convenient. Experimental results show that the system can be stably tracking the selected target with fast response speed and relatively high tracking accuracy.

Download Full-text

Electrochemical NOx Sensors for Automotive Diesel Exhaust

MRS Proceedings ◽

10.1557/proc-756-ee11.3 ◽

2002 ◽

Vol 756 ◽

Author(s):

Louis P. Martin ◽

Ai-Q. Pham ◽

Robert S. Glass

Keyword(s):

High Sensitivity ◽

Response Speed ◽

Fast Response ◽

Exhaust Gas ◽

Oxides Of Nitrogen ◽

Monitoring And Control ◽

Stabilized Zirconia ◽

Exact Role ◽

And Control

ABSTRACTNew emissions regulations will increase the need for compact, inexpensive sensors for monitoring and control of automotive exhaust gas pollutants. Species of interest include hydrocarbons, carbon monoxide, and oxides of nitrogen (NOx). The current work is directed towards the development of fast, high sensitivity electrochemical NOx sensors for automotive diesel applications. We have investigated potentiometric NO sensors with good sensitivity and fast response when operated in 10% O2. The sensors consist of yttria-stabilized zirconia substrates attached with NiCr2O4 sensing electrodes and Pt reference electrodes. A composite NiCr2O4:Rh sensing electrode is shown to give significantly faster response than NiCr2O4 alone. The exact role of the Rh in enhancing the response speed is not clear at present. However, the Rh appears to accumulate at the contacts between the NiCr2O4 particles and may enhance the inter-particle electronic conduction. Ongoing testing of these sensors is being performed to elucidate the sensing mechanisms and to quantify cross sensitivity to, for example, NO2.

Download Full-text