scholarly journals Design of a Small Automated Telescope for Indian Universities

2001 ◽  
Vol 24 (3) ◽  
pp. 303-306
Author(s):  
Mandayam N. Anandaram ◽  
B.A. Kagali ◽  
S.P. Bhatnagar

AbstractWe have constructed a computer controlled telescope using a 0.36-m f/11 Celestron optical tube assembly for teaching and research applications. We have constructed a heavy duty fork-type equatorial mount fitted with precision machined 24 inch drive disks for both axes. These are friction driven by stepper motors through one inch rollers. We have used an open loop control system triggerable by an ST-4 CCD camera to acquire and track any target object. Our telescope can home in on any target within a range of two arc-minutes. We have employed a commercial stepper motor controller card for which we have written a user friendly pc based telescope control software in C. Photometry using a solid state photometer, and imaging by an ST-6 CCD camera are possible.We consider that this project is suitable for those wishing to construct some parts of a telescope and understand the principles of operation. A simpler model of this telescope could use DC motors instead of stepper motors. We shall be happy to send our design diagrams and details to those interested. This project was funded by the DST, and was assisted by IUCAA, Pune.

Author(s):  
Amro Shafik ◽  
Salah Haridy

Computer Numerical Control (CNC) is a technology that converts coded instructions and numerical data into sequential actions that describe the motion of machine axes or the behavior of an end effector. Nowadays, CNC technology has been introduced to different stages of production, such as rapid prototyping, machining and finishing processes, testing, packaging, and warehousing. The main objective of this chapter is to introduce a methodology for design and implementation of a simple and low-cost educational CNC prototype. The machine consists of three independent axes driven by stepper motors through an open-loop control system. Output pulses from the parallel port of Personal Computer (PC) are used to drive the stepper motors after processing by an interface card. A flexible, responsive, and real-time Visual C# program is developed to control the motion of the machine axes. The integrated design proposed in this chapter can provide engineers and students in academic institutions with a simple foundation to efficiently build a CNC machine based on the available resources. Moreover, the proposed prototype can be used for educational purposes, demonstrations, and future research.


2011 ◽  
Vol 418-420 ◽  
pp. 1865-1868
Author(s):  
Ming Jin Yang ◽  
Xi Wen Li ◽  
Zhi Gang Wang ◽  
Tie Lin Shi

The performance of speed regulating is very important to the mixing process with safe, efficient operation and high quality of production. Strategies and practices of responses and optimization of a PID-based speed regulating system of a planetary mixer were presented in this paper. Research results show that: by means of the signal constraint function presented by Simulink Response Optimization, optimization PID parameters of the 2-DOF-PID controller can be obtained, and the response of close-loop control system has quite good performance of overshoot, response time, and stability compared with an open-loop control system.


2016 ◽  
Vol 28 (04) ◽  
pp. 1650026
Author(s):  
K. Rouhollahi ◽  
M. Emadi Andani ◽  
S. M. Karbassi ◽  
M. Mojiri

Deep brain stimulation (DBS) is one of the most effective neurosurgical procedures to reduce Parkinsons tremor. The conventional method of DBS is open loop stimulation of one area of basal ganglia (BG). On the other hand, existing feedback causes the reduction of additional stimulatory signal delivered to the brain which results in the reduction of the side effects caused by the excessive stimulation intensity. Actually, the stimulatory intensity of the controllers is reduced proportionally by the reduction of hands tremor, which is in fact the intended rehabilitation of the disease. The meaningful objective of this study is to design an architecture of controllers to decrease three criteria. The first one is the hand’s tremor, the second one is the level of delivered stimulation signal to brain in disease condition and the third one is the ratio of the level of delivered stimulation signal in health condition to disease condition. In order to achieve these objectives, a new architecture of a closed loop control system to stimulate two areas of BG at the same time is presented. One area (STN: subthalamic nucleus) is stimulated with a state feedback (SF) controller (pole placement method) and the other area (GPi: globus pallidus internal) is stimulated with a partial state feedback controller (PSFC). Considering these criteria, the results illustrate that stimulating two areas leads to a suitable performance. Simulation results show that the PSF and SF controllers are robust enough to the variations of the system parameters. Moreover, we are able to estimate the parameters of BG model in real time; it is a valuable method to update the time variable parameters of this model.


Author(s):  
Roberto Strada ◽  
Alberto Oldani

Electro-hydraulic elevators are widely used systems, especially in low level buildings, due to their very good ratio between power generation and dynamic response. Generally, the goal of an elevator system is just to reach the floor with a precision enough to be comfortable for the passengers, without the need to follow a specific law of motion; hence an open-loop control system could be enough. Otherwise such a kind of solution reduces the number of components, bringing down the costs of production. On the other hand a complete knowledge of the mechanical system’s behaviour is required. In this work we deal with the analysis of the behaviour of a commercial hydraulic elevator driven by an open loop control that monitors the downstream pressure of the proportional valve supplying the cylinder. At the end of the paper, a closed loop solution based on the pressure measurement and on the motion time is proposed.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Zhong Wu ◽  
Haotun Lyu ◽  
Yongli Shi ◽  
Di Shi

Open-loop operation mode is often used to control the Brushless DC Motors (BLDCMs) without rotor position sensors when the back electromotive force (EMF) is too weak due to the very low rotor velocity. The rotor position information is not necessary in this mode and the stator windings are supplied with voltages under a certain ratio of the amplitude to the frequency. However, the rotor synchronization will be destroyed once if the commutation instant is inappropriate. In order to improve the reliability of the open-loop operation mode, a dynamic equation is established to represent the synchronization error between the rotor and the stator. Thereafter, the stability of the open-loop control mode is analyzed by using Lyapunov indirect method. Theoretical analysis indicates that the open-loop control mode is asymptotically stable only when the commutation instant of the stator current lags behind the ideal one suitably. Finally, theoretical analysis is verified through the experimental results of a certain BLDCM.


2010 ◽  
Vol 43 ◽  
pp. 207-210 ◽  
Author(s):  
Ju Li ◽  
Hui Ping Shen ◽  
Y.X. Jiang ◽  
Jia Ming Deng ◽  
Shan Shu Liu ◽  
...  

This paper studied a novel 3-DOF hybrid robot, and invented a new hybrid structure which was composed of 2-DOF parallel structure and 1-DOF serial structure. The structure of this mechanism was simple, stiffness and positioning accuracy was high. The control system based on ARM micro-controller was a step motor open-loop control system, which features compact and low cost while the control accuracy can be guaranteed. In this paper, the body composition of the robot was described, and its inverse kinematics were derived and further simplified. Hardware and software of the motion control system was designed in detail and experimented through prototype.


2014 ◽  
Vol 602-605 ◽  
pp. 1157-1160
Author(s):  
Mei Yu ◽  
Guo Wei Liu ◽  
Bing Kong

In view of the present mining spraying manipulator operation is not flexible ,spraying effect is poor, susceptible to interference and other issues, this paper studies and realizes a kind of low cost, strong practicability of spraying manipulator control system. Using S7-200PLC and 2MA860H drive to control the 86BYG250A stepper motor open-loop control system, and the precise position control is realized. By controlling of the x-y axis mine spraying manipulator. Validate the system operation is simple, highly efficient and stable, energy conservation and environmental protection, strong anti-jamming capability, it can be widely used in all kinds of mining equipment.


2014 ◽  
Vol 1030-1032 ◽  
pp. 1181-1184
Author(s):  
Miao Shang ◽  
Guo Min Lin ◽  
Wen Guang Zhang ◽  
Fei Zhou

The basic composition of the landing gear simulator test-bed is discussed; The open loop control system experiment, closed-loop light control system experiment, the closed loop load control system are completed for the test system; The reliability and stability of test-bed system are validated by the experiment; The technical indexes of the landing gear simulation test-bed and the design requirement of electric control system are validated.


Sign in / Sign up

Export Citation Format

Share Document