Improving the accuracy of the time and frequency signal transmission over coaxial cable

2020 ◽  
pp. 55-59
Author(s):  
Alexey P. Grunin ◽  
Denis G. Kalinov ◽  
Dmitriy S. Migunov
Keyword(s):  
Signal Transmission ◽  
Coaxial Cable ◽  
Frequency Signal ◽  
Proportional Integral ◽  
Pid Algorithm ◽  
Integral Temperature ◽  
The Stability ◽  
Transmitted Frequency

This paper assesses the effect of wide temperature differences of cable segments on the stability of the transmitted frequency. Paper presents a method for determining the integral temperature of a long cable, as well as a method for compensating the introduced instability of the transmitted frequency. A method for stabilizing the integral temperature of a long coaxial cable using a proportional-integral-differentiating algorithm (PID) algorithm and a distributed heater is also proposed.

Unification of global vertical height system using precise frequency signal links

2020 ◽  
Author(s):  
Ziyu Shen ◽  
Wen-Bin Shen ◽  
Shuangxi Zhang
Keyword(s):  
International Association ◽  
Signal Transmission ◽  
Frequency Signal ◽  
Height Difference ◽  
The Us ◽  
Height System ◽  
Height Datum ◽  
Simulation Results ◽  
The Stability ◽  
Vertical Height

<p>The realization of International Height Reference System (IHRS) is one of the major tasks of the International Association of Geodesy (IAG). Here we formulate a framework for connecting two local VHSs using ultra-precise frequency signal transmission links between satellites and ground stations, which is referred to as satellite frequency signal transmission (SFST) approach. The SFST approach can directly determine the geopotential difference between two ground datum stations without location restrictions, and consequently determine the height difference of the two VHSs. Simulation results show that the China’s VHS and the US’s VHS can be unified at the accuracy of several centimeters, provided that the stability of atomic clocks used on board the satellite and on ground datum stations reach the highest level of current technology, about 4.8×10<sup>-18</sup> in 100 s. The SFST approach is promising to unify the global vertical height datum in centimeter level in future, providing a new way for the IHRS realization. This study is supported by NSFCs (grant Nos. 41721003, 41631072, 41874023, 41804012, 41429401, 41574007) and Natural Science Foundation of Hubei Province of China (grant No. 2019CFB611).</p>

Retuning the actuator proportional–integral–derivative controller of spinning missiles

2016 ◽  
Vol 231 (14) ◽  
pp. 2594-2602 ◽  
Author(s):  
Wei Zhou ◽  
Shuxing Yang ◽  
Liangyu Zhao
Keyword(s):  
Angular Motion ◽  
Proportional Integral Derivative ◽  
Proportional Integral Derivative Controller ◽  
Proportional Integral ◽  
Out Of Plane ◽  
Integral Element ◽  
The Stability ◽  
Proportional Derivative Controller

The hinge moment acting on the actuator will cause an out-of-plane moment, which is a destabilizing factor to the angular motion of spinning missiles. A new tuning criterion for the actuator controller is proposed to decrease the out-of-plane moment. It is noted that the integral element does not decrease the out-of-plane moment. A carefully designed proportional–derivative controller with some compromises can ensure the stability of the missile and provide good performance for the actuator.

scholarly journals Design and development of polymerase chain reaction thermal cycler using proportional-integral temperature controller

2018 ◽  
Vol 14 (2) ◽  
pp. 213-218
Author(s):  
Chong Kim Soon ◽  
Nawoor Anusha Devi ◽  
Kok Beng Gan ◽  
Sue-Mian Then
Keyword(s):  
Polymerase Chain Reaction ◽  
Low Cost ◽  
Maximum Temperature ◽  
Gradient System ◽  
Chain Reaction ◽  
Temperature Controller ◽  
Proportional Integral ◽  
Integral Temperature ◽  
Polymerase Chain ◽  
Thermal Cycler

A thermal cycler is used to amplify segments of DNA using the polymerase chain reaction (PCR). It is an instrument that requires precise temperature control and rapid temperature changes for certain experimental protocols. However, the commercial thermal cyclers are still bulky, expensive and limited for laboratory use only.  As such it is difficult for on-site molecular screening and diagnostics. In this work, a portable and low cost thermal cycler was designed and developed. The thermal cycler block was designed to fit six microcentrifuge tubes. A Proportional-Integral temperature controller was used to control the thermal cycler block temperature. The results showed that the maximum temperature ramp rate of the developed thermal cycler was 5.5 °C/s. The proportional gain (Kp) and integral gain (Ki) of the PI controller were 15 A/V and 1.8 A/Vs respectively. Finally, the developed thermal cycler successfully amplified six DNA samples at the expected molecular weight of 150 base pair. It has been validated using the Eppendorf Mastercycler nexus gradient system and gel electrophoresis analysis

scholarly journals A stable proportional–proportional integral tracking controller with self-organizing fuzzy-tuned gains for parallel robots

2019 ◽  
Vol 16 (1) ◽  
pp. 172988141881995
Author(s):  
Francisco G Salas ◽  
Jorge Orrante-Sakanassi ◽  
Raymundo Juarez-del-Toro ◽  
Ricardo P Parada
Keyword(s):  
Stability Analysis ◽  
Performance Index ◽  
Closed Loop ◽  
Tracking Error ◽  
Parallel Robots ◽  
Control Loop ◽  
Closed Loop System ◽  
Proportional Integral ◽  
The Stability ◽  
Self Organizing

Parallel robots are nowadays used in many high-precision tasks. The dynamics of parallel robots is naturally more complex than the dynamics of serial robots, due to their kinematic structure composed by closed chains. In addition, their current high-precision applications demand the innovation of more effective and robust motion controllers. This has motivated researchers to propose novel and more robust controllers that can perform the motion control tasks of these manipulators. In this article, a two-loop proportional–proportional integral controller for trajectory tracking control of parallel robots is proposed. In the proposed scheme, the gains of the proportional integral control loop are constant, while the gains of the proportional control loop are online tuned by a novel self-organizing fuzzy algorithm. This algorithm generates a performance index of the overall controller based on the past and the current tracking error. Such a performance index is then used to modify some parameters of fuzzy membership functions, which are part of a fuzzy inference engine. This fuzzy engine receives, in turn, the tracking error as input and produces an increment (positive or negative) to the current gain. The stability analysis of the closed-loop system of the proposed controller applied to the model of a parallel manipulator is carried on, which results in the uniform ultimate boundedness of the solutions of the closed-loop system. Moreover, the stability analysis developed for proportional–proportional integral variable gains schemes is valid not only when using a self-organizing fuzzy algorithm for gain-tuning but also with other gain-tuning algorithms, only providing that the produced gains meet the criterion for boundedness of the solutions. Furthermore, the superior performance of the proposed controller is validated by numerical simulations of its application to the model of a planar three-degree-of-freedom parallel robot. The results of numerical simulations of a proportional integral derivative controller and a fuzzy-tuned proportional derivative controller applied to the model of the robot are also obtained for comparison purposes.

scholarly journals Design optimization of multi-objective proportional–integral–derivative controllers for enhanced handling quality of a twin-engine, propeller-driven airplane

2020 ◽  
Vol 12 (6) ◽  
pp. 168781402092317
Author(s):  
Mohsen Rostami ◽  
Joon Chung ◽  
Hyeong Uk Park
Keyword(s):  
Genetic Algorithm ◽  
Design Optimization ◽  
Proportional Integral Derivative ◽  
Optimum Result ◽  
Proportional Integral ◽  
Multi Objective ◽  
Directional Motion ◽  
The Stability ◽  
Handling Quality

Herein, the design optimization of multi-objective controllers for the lateral–directional motion using proportional–integral–derivative controllers for a twin-engine, propeller-driven airplane is presented. The design optimization has been accomplished using the genetic algorithm and the main goal was to enhance the handling quality of the aircraft. The proportional–integral–derivative controllers have been designed such that not only the stability of the lateral–directional motion was satisfied but also the optimum result in longitudinal trim condition was achieved through genetic algorithm. Using genetic algorithm optimization, the handling quality was improved and placed in level 1 from level 2 for the proposed aircraft. A comprehensive sensitivity analysis to different velocities, altitudes and centre of mass positions is presented. Also, the performance of the genetic algorithm has been compared to the case where the particle swarm optimization tool is implemented. In this work, the aerodynamic coefficients as well as the stability and control derivatives were predicted using analytical and semi-empirical methods validated for this type of aircraft.

Design of Stabilized Platform Controller for Mobile Satellite Communication System

2011 ◽  
Vol 130-134 ◽  
pp. 2133-2137
Author(s):  
Tao Yuan ◽  
Yu Wang
Keyword(s):  
Communication System ◽  
Satellite Communication ◽  
Strong Suppression ◽  
Satellite Communication System ◽  
Pid Algorithm ◽  
Speed Change ◽  
Mobile Satellite ◽  
The Stability ◽  
Stabilized Platform ◽  
Mobile Satellite Communication

The stabilized platform servo system ensures the carrier communicating with satellites stably while in motion. The key to this system is to isolate disturbance coursed by the moving of the carrier and maintain the stability of antenna directivity. This paper has compared PID algorithm and I-PD algorithm, and designed a control scheme for the stabilized platform using the combination of speed-change integral I-PD algorithm and feed-forward control. The results of the simulation and actual testing indicate that the design this paper presents has a strong suppression to disturbance and meets the precision requirements of the mobile satellite communication system.

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