scholarly journals Bilinear reduced order approximate model of parabolic distributed solar collectors

Solar Energy ◽  
2016 ◽  
Vol 131 ◽  
pp. 71-80 ◽  
Author(s):  
S. Elmetennani ◽  
T.M. Laleg-Kirati
Keyword(s):  
Approximate Model ◽  
Solar Collectors ◽  
Reduced Order

Frequency Analysis of Linearly Coupled Modes of MEMS Arrays

2016 ◽  
Vol 138 (2) ◽  
Author(s):  
Prashant N. Kambali ◽  
Gyanadutta Swain ◽  
Ashok Kumar Pandey
Keyword(s):  
Frequency Tuning ◽  
Approximate Model ◽  
Sensors And Actuators ◽  
Coupled Modes ◽  
Coupling Region ◽  
Reduced Order ◽  
Single Beam ◽  
Tuning Parameters ◽  
Out Of Plane ◽  
Fringing Field

Microelectromechanical system (MEMS) based arrays have been employed to increase the bandwidth and sensitivity of many sensors and actuators. In this paper, we present an approximate model to demonstrate the tuning of in-plane and out-of-plane frequencies of MEMS arrays consisting of fixed–fixed beams. Subsequently, we apply the Galerkin's method with single approximate mode to obtain the reduced-order static and dynamic equations. Corresponding to a given direct current (DC) voltage, we first solve the static equations and then obtain corresponding frequencies from the dynamic equation for single beam and arrays of multibeams. We compare the model with available experimental results. Later, we show the influence of different frequency tuning parameters such as the initial tensions, fringing field coefficients and the variable inter beam gaps between the microbeam and electrodes to control the coupling region and different modal frequencies of the beam. Finally, we obtain a compact model which can be used in optimizing the bandwidth and sensitivity of microbeams array.

scholarly journals Improved Linear Active Disturbance Rejection Control for Lever-Type Electric Erection System with Varying Loads and Low-Resolution Encoder

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Hailong Niu ◽  
Qinhe Gao ◽  
Zhihao Liu ◽  
Shengjin Tang ◽  
Wenliang Guan
Keyword(s):  
Trajectory Tracking ◽  
Disturbance Rejection ◽  
Approximate Model ◽  
Control Mode ◽  
Active Disturbance Rejection Control ◽  
Tracking Accuracy ◽  
Low Resolution ◽  
Reduced Order ◽  
Active Disturbance Rejection ◽  
Disturbance Rejection Control

The lever-type electric erection system is a novel kind of erection system and the experimental platform in this paper operates with varying loads and low-resolution encoder. For high accuracy trajectory tracking, linear active disturbance rejection control (LADRC) is introduced. An approximate model, consisting of the servo system configured at velocity control mode and the lever-type erection mechanism, is built by means of system identification and curve fitting. Reduced-order LADRC based on the further simplified model is proposed to improve tracking accuracy and robustness. As comparisons, traditional LADRC and PID with high-gain tracking differentiator (HGTD) are designed. Simulation and experimental results indicate that reduced-order LADRC can realize higher trajectory tracking accuracy with low-resolution encoder and has better robustness to variation in erection loads, compared with traditional LADRC and PID with HGTD.

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