An FEC-based error control scheme for wireless MPEG-4 video transmission

2002 ◽  
Author(s):  
J. Cai ◽  
Qian Zhang ◽  
Wenwu Zhu ◽  
C.W. Chen
Keyword(s):  
Error Control ◽  
Video Transmission ◽  
Control Scheme

scholarly journals Observer-based robust integral of the sign of the error control of class I of underactuated mechanical systems: Theory and real-time experiments

2021 ◽  
pp. 014233122110313
Author(s):  
Afef Hfaiedh ◽  
Ahmed Chemori ◽  
Afef Abdelkrim
Keyword(s):  
Real Time ◽  
Error Control ◽  
Degrees Of Freedom ◽  
Sliding Mode ◽  
Mechanical Systems ◽  
Class I ◽  
Control Input ◽  
Underactuated Mechanical Systems ◽  
Control Scheme ◽  
And Performance

In this paper, the control problem of a class I of underactuated mechanical systems (UMSs) is addressed. The considered class includes nonlinear UMSs with two degrees of freedom and one control input. Firstly, we propose the design of a robust integral of the sign of the error (RISE) control law, adequate for this special class. Based on a change of coordinates, the dynamics is transformed into a strict-feedback (SF) form. A Lyapunov-based technique is then employed to prove the asymptotic stability of the resulting closed-loop system. Numerical simulation results show the robustness and performance of the original RISE toward parametric uncertainties and disturbance rejection. A comparative study with a conventional sliding mode control reveals a significant robustness improvement with the proposed original RISE controller. However, in real-time experiments, the amplification of the measurement noise is a major problem. It has an impact on the behaviour of the motor and reduces the performance of the system. To deal with this issue, we propose to estimate the velocity using the robust Levant differentiator instead of the numerical derivative. Real-time experiments were performed on the testbed of the inertia wheel inverted pendulum to demonstrate the relevance of the proposed observer-based RISE control scheme. The obtained real-time experimental results and the obtained evaluation indices show clearly a better performance of the proposed observer-based RISE approach compared to the sliding mode and the original RISE controllers.

A Novel Control Scheme for VBR Video Transmission over ATM Networks

1999 ◽  
pp. 281-287
Author(s):  
C. Perissinotto ◽  
G. Parladori ◽  
G. A. Mian
Keyword(s):  
Video Transmission ◽  
Atm Networks ◽  
Control Scheme ◽  
Vbr Video

Theoretical Modification on Optic Properties for Transmission-Mode GaAs Photocathode Module

2013 ◽  
Vol 631-632 ◽  
pp. 181-185
Author(s):  
Ya Juan Xiong ◽  
Jing Zhao ◽  
Ben Kang Chang
Keyword(s):  
Optical Properties ◽  
Error Control ◽  
Transmission Mode ◽  
Total Thickness ◽  
Initial Values ◽  
Control Scheme ◽  
Variation Range

To explore the optic properties of transmission-mode GaAs photocathode module, experimental and theoretical values of reflectance and transmittance of photocathode module has been compared. it showns that experemental curves cannot tally with theoretical curves completely. The variation range of initial values of thickness is firstly setted. Modifing transmittance formula by a fitting coefficient A, optical properties is fitted using the method of error control. R-T combined error reduced from 15.2% to 4.9% using R-T combined error control scheme. Optimal fitting values of thickness of photocathode module are obtained, which are d1= 110 nm, d2= 1019 nm, d3= 1491 nm. And the error of total thickness is 2.9%.

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