Dynamic High-Gain Observer to Estimate Pneumatic Actuator Temperatures

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
A. Ayadi ◽  
S. Hajji ◽  
M. Smaoui ◽  
A. Chaari ◽  
M. Farza
Keyword(s):  
Design Parameter ◽  
High Gain ◽  
Accurate Estimation ◽  
Observation Error ◽  
Time Varying ◽  
Error Norm ◽  
Output Noise ◽  
Noise Measurements ◽  
Electropneumatic System ◽  
Simulation Results

This paper deals with the estimation of the actuator temperature in an electropneumatic system. First, an appropriate nonlinear system that accounts for the actuator temperature dynamics is introduced. Then in order to overcome the difficulty of installing temperatures sensors in each chamber of the actuator, two nonlinear high-gain observers are proposed to provide online estimate of these temperatures. The gain of both observers can be tuned by the choice of a scalar design parameter. However, the design parameter is constant for the first observer and its choice has to satisfy a compromise between an accurate estimation of the state estimation and a satisfactory sensitivity of the observer with respect to the unavoidable output noise measurements. This difficulty is overcome in the second observer since the scalar design parameter is time varying and is governed by a Riccatti differential equation. The involved adaptation process of the design parameter is mainly driven by the power of the output observation error norm computed on a moving horizon window. Simulation results are given to show the effectiveness of the proposed observers and in particular to compare the performance of both observers, namely, the accuracy of the respective estimates and their sensitivity with respect to noise measurements.

scholarly journals Unknown Disturbance Estimation for a PMSM with a Hybrid Sliding Mode Observer

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Gang Chen ◽  
Yong Zhou ◽  
TingTing Gao ◽  
Qicai Zhou
Keyword(s):  
Permanent Magnet ◽  
Digital Filter ◽  
Sliding Mode ◽  
Permanent Magnet Synchronous Motor ◽  
High Gain ◽  
Sliding Mode Observer ◽  
Time Varying ◽  
Disturbance Estimation ◽  
Simulation Results ◽  
Unknown Disturbance

A hybrid sliding mode observer that combines high gain feedback and a high-order sliding mode term is developed to identify the time-varying disturbance for a permanent-magnet synchronous motor (PMSM). Based on the measurable current and the position, the unknown disturbance can be identified from the sliding mode term without digital filter effect. It is then used to enhance the robustness of the speed control dynamics. For ease of implementation in real applications, such as DSP and FPGA, the proposed observer is properly designed to avoid complex mathematical operators. Simulation results are given to illustrate the performance of the proposed observer.

scholarly journals Time-Varying Impedance Control of Port Hamiltonian System with a New Energy-Storing Tank

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Min Zheng ◽  
Tangqing Yuan ◽  
Tao Huang
Keyword(s):  
Control Method ◽  
Impedance Control ◽  
Conservative System ◽  
Time Varying ◽  
Control Performance ◽  
Singularity Problem ◽  
Numerical Examples ◽  
New Energy ◽  
Simulation Results ◽  
New Framework

In order to guarantee the passivity of a kind of conservative system, the port Hamiltonian framework combined with a new energy tank is proposed in this paper. A time-varying impedance controller is designed based on this new framework. The time-varying impedance control method is an extension of conventional impedance control and overcomes the singularity problem that existed in the traditional form of energy tank. The validity of the controller designed in this paper is shown by numerical examples. The simulation results show that the proposed controller can not only eliminate the singularity problem but can also improve the control performance.

Iterative learning algorithm with a quadratic criterion for linear time-varying systems

2002 ◽  
Vol 216 (3) ◽  
pp. 309-316 ◽  
Author(s):  
S N Huang ◽  
K K Tan ◽  
T H Lee
Keyword(s):  
Learning Algorithm ◽  
Linear Time ◽  
Tracking Error ◽  
Iterative Learning ◽  
Tracking Performance ◽  
Time Varying ◽  
Control Scheme ◽  
Time Varying Systems ◽  
Simulation Results ◽  
Learning Law

A novel iterative learning controller for linear time-varying systems is developed. The learning law is derived on the basis of a quadratic criterion. This control scheme does not include package information. The advantage of the proposed learning law is that the convergence is guaranteed without the need for empirical choice of parameters. Furthermore, the tracking error on the final iteration will be a class K function of the bounds on the uncertainties. Finally, simulation results reveal that the proposed control has a good setpoint tracking performance.

scholarly journals A Robust Discontinuous Phase Unwrapping Based on Least-Squares Orientation Estimator

Electronics ◽  
2021 ◽  
Vol 10 (22) ◽  
pp. 2871
Author(s):  
Gaoxu Deng ◽  
Shiqian Wu ◽  
Shiyang Zhou ◽  
Bin Chen ◽  
Yucheng Liao
Keyword(s):  
Least Squares ◽  
Weighted Least Squares ◽  
Bilateral Filter ◽  
Phase Unwrapping ◽  
Noise Variance ◽  
Post Processing ◽  
Quadratic Error ◽  
Error Norm ◽  
Discontinuous Phase ◽  
Simulation Results

Weighted least-squares (WLS) phase unwrapping is widely used in optical engineering. However, this technique still has issues in coping with discontinuity as well as noise. In this paper, a new WLS phase unwrapping algorithm based on the least-squares orientation estimator (LSOE) is proposed to improve phase unwrapping robustness. Specifically, the proposed LSOE employs a quadratic error norm to constrain the distance between gradients and orientation vectors. The estimated orientation is then used to indicate the wrapped phase quality, which is in terms of a weight mask. The weight mask is calculated by post-processing, including a bilateral filter, STDS, and numerical relabeling. Simulation results show that the proposed method can work in a scenario in which the noise variance is 1.5. Comparisons with the four WLS phase unwrapping methods indicate that the proposed method provides the best accuracy in terms of segmentation mean error under the noisy patterns.

scholarly journals Principal Component Analysis For ICP Pose Estimation Of Space Structures

2021 ◽  
Author(s):  
Lun H. Mark
Keyword(s):  
Pose Estimation ◽  
Point Cloud ◽  
Principal Component ◽  
Point Clouds ◽  
Optimal Combination ◽  
Estimation Accuracy ◽  
Space Structures ◽  
Complex Objects ◽  
Error Norm ◽  
Simulation Results

This thesis investigates how geometry of complex objects is related to LIDAR scanning with the Iterative Closest Point (ICP) pose estimation and provides statistical means to assess the pose accuracy. LIDAR scanners have become essential parts of space vision systems for autonomous docking and rendezvous. Principal Componenet Analysis based geometric constraint indices have been found to be strongly related to the pose error norm and the error of each individual degree of freedom. This leads to the development of several strategies for identifying the best view of an object and the optimal combination of localized scanned areas of the object's surface to achieve accurate pose estimation. Also investigated is the possible relation between the ICP pose estimation accuracy and the districution or allocation of the point cloud. The simulation results were validated using point clouds generated by scanning models of Quicksat and a cuboctahedron using Neptec's TriDAR scanner.

scholarly journals Principal Component Analysis For ICP Pose Estimation Of Space Structures

2021 ◽  
Author(s):  
Lun H. Mark
Keyword(s):  
Pose Estimation ◽  
Point Cloud ◽  
Principal Component ◽  
Point Clouds ◽  
Optimal Combination ◽  
Estimation Accuracy ◽  
Space Structures ◽  
Complex Objects ◽  
Error Norm ◽  
Simulation Results

This thesis investigates how geometry of complex objects is related to LIDAR scanning with the Iterative Closest Point (ICP) pose estimation and provides statistical means to assess the pose accuracy. LIDAR scanners have become essential parts of space vision systems for autonomous docking and rendezvous. Principal Componenet Analysis based geometric constraint indices have been found to be strongly related to the pose error norm and the error of each individual degree of freedom. This leads to the development of several strategies for identifying the best view of an object and the optimal combination of localized scanned areas of the object's surface to achieve accurate pose estimation. Also investigated is the possible relation between the ICP pose estimation accuracy and the districution or allocation of the point cloud. The simulation results were validated using point clouds generated by scanning models of Quicksat and a cuboctahedron using Neptec's TriDAR scanner.

Traffic Fuzzy Controller's Improvement Based on Self-Adaptive Optimal Algorithm

2012 ◽  
Vol 562-564 ◽  
pp. 1414-1417
Author(s):  
Zhi Yi Xu ◽  
Da Lu Guan ◽  
Ai Long Fan
Keyword(s):  
Mathematical Model ◽  
Large Scale ◽  
Fuzzy Controller ◽  
Optimal Algorithm ◽  
Signal Control ◽  
Traffic Signal Control ◽  
Time Varying ◽  
Large Scale Systems ◽  
Simulation Results ◽  
Self Adaptive

The transport system is a nonlinear, time-varying, lagging large-scale systems. Fuzzy control does not need to build a precise mathematical model, can be easily integrated people's thinking and experience, and is suitable for applications in the traffic signal control system. Here,a self-adaptive optimal algorithm was used to improve the traditional fuzzy controller. Simulation results show that the improved system has higher availability.

scholarly journals Unknown Inputs Nonlinear Observer for an Activated Sludge Process

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Feten Smida ◽  
Taoufik Ladhari ◽  
Salim Hadj Saïd ◽  
Faouzi M’sahli
Keyword(s):  
Activated Sludge ◽  
High Gain ◽  
The Other ◽  
Nonlinear Observer ◽  
Dynamics Simulation ◽  
Activated Sludge Process ◽  
Unknown Inputs ◽  
Simulation Results ◽  
Economic Concentration ◽  
Substrate Concentrations

This paper deals with the jointly estimation problem of unknown inputs and nonmeasured states of one altering aerated activated sludge process (ASP). In order to provide accurate and economic concentration measures during aerobic and anoxic phases, a cascade high gain observer (HGO) approach is developed. Only two concentrations are available; the other process’s states are assumed unavailable. The observer converges asymptotically and it leads to a good estimation of the unavailable states which are the ammonia and substrate concentration, as well as a quite reconstruction of the unknown inputs, which are the influent ammonia and the influent substrate concentrations. To highlight the efficiency of the proposed HGO with this MIMO system’s dynamics, simulation results are validated with experimental data.

Design of a high-gain dual-band antipodal Vivaldi antenna array for 5G communications

2021 ◽  
pp. 1-9
Author(s):  
Sumit Kumar ◽  
Amruta S. Dixit
Keyword(s):  
Frequency Spectrum ◽  
Impedance Matching ◽  
High Gain ◽  
Dual Band ◽  
Dual Frequency ◽  
Band Frequency ◽  
Dielectric Lens ◽  
Bottom Side ◽  
Simulation Results ◽  
Vivaldi Antenna

Abstract This paper presents a dual-band 1 × 4 antipodal Vivaldi antenna (AVA) array with high gain to operate over a dual-frequency band that covers the 5G frequency spectrum. The gain is enhanced by employing a dielectric lens (DL). The AVA array consists of four radiating patch elements, corrugations, DL, and array feeding network on the top side. The bottom side contains four radiating patches which are the mirror images of top radiating patches. The designed AVA contains 1 × 4 array antenna elements with a DL that is operating in the ranges of 24.59–24.98 and 27.06–29 GHz. The dimensions of the designed antenna are 97.2 mm × 71.2 mm × 0.8 mm. For the improvement in gain and impedance matching at the dual-band frequency, corrugation and feeding network techniques are used. The gain obtained is about 8–12 dBi. AVA array is tested after fabrication and the measured results are reliable with the simulation results.

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