scholarly journals The Study of 3D Reaching Tasks on Visual Servoing Using Quaternion

2021 ◽  
Author(s):  
Liucun Zhu ◽  
◽  
Junqi Luo ◽  
Mingyou Chen ◽  
Haofeng Deng ◽  
...  
Keyword(s):  
Performance Improvement ◽  
Visual Servoing ◽  
Jacobian Matrix ◽  
Laser Scanner ◽  
Three Dimension ◽  
Reaching Tasks ◽  
Significant Performance ◽  
Simulation Results ◽  
Conventional Methods

The image-based monocular visual servoing is difficult to realize the grasping task on three-dimension. This study presented a method of quaternion on 3D reaching tasks of visual servoing. This method used a camera and a laser scanner to acquire the information of the images and the depth. Then the parameters of Jacobian matrix could be determined by the method of the quaternion. A particular constraint mechanism was also proposed to optimize the reaching trajectory of the robot. The simulation results demonstrated our proposed method could implement the 3D reaching tasks successfully and had a significant performance improvement compared to conventional methods.

A Novel DOA Estimation Method for Wideband Signals

2011 ◽  
Vol 403-408 ◽  
pp. 2861-2865
Author(s):  
Fu Gang Liu ◽  
Ming Diao
Keyword(s):  
Performance Improvement ◽  
Estimation Method ◽  
Doa Estimation ◽  
Estimation Bias ◽  
Wideband Signals ◽  
Significant Performance ◽  
Simulation Results ◽  
The Impact ◽  
Real Time Application ◽  
Conventional Algorithm

For direction of arrival (DOA) estimation of wideband signals, the traditional algorithms’ estimating accuracy and complexity were mainly affected by pre-estimation of DOA. By forming an angle set which elements were arithmetic progressions in the range of possible arriving angles, the algorithm used the new angle vector to replace the preliminary estimation of arriving angles. It can avoid the impact of pre-estimation bias on performance of DOA estimation and greatly reduce the amount of computation and the consumed time for DOA estimation to favor the real-time application of wideband DOA estimation. The simulation results showed that the proposed algorithm was able to provide significant performance improvement over the conventional algorithm.

Consideration of structural constraints in passive rotor blade design for improved performance

2015 ◽  
Vol 119 (1222) ◽  
pp. 1513-1539 ◽  
Author(s):  
J. W. Lim
Keyword(s):  
Performance Improvement ◽  
Rotor Blade ◽  
Parametric Design ◽  
Control Point ◽  
Bending Moment ◽  
Structural Constraints ◽  
Design Variables ◽  
Significant Performance ◽  
Structural Redesign ◽  
Improved Performance

AbstractThis design study applied parameterisation to rotor blade for improved performance. In the design, parametric equations were used to represent blade planform changes over the existing rotor blade model. Design variables included blade twist, sweep, dihedral, and radial control point. Updates to the blade structural properties with changes in the design variables allowed accurate evaluation of performance objectives and realistic structural constraints – blade stability, steady moments (flap bending, chord bending, and torsion), and the high g manoeuvring pitch link loads. Performance improvement was demonstrated with multiple parametric designs. Using a parametric design with advanced aerofoils, the predicted power reduction was 1·0% in hover, 10·0% at μ = 0·30, and 17·0% at μ = 0·40 relative to the baseline UH-60A rotor, but these were obtained with a 35% increase in the steady chord bending moment at μ = 0·30 and a 20% increase in the half peak-to-peak pitch link load during the UH-60A UTTAS manoeuvre Low vibration was maintained for this design. More rigorous design efforts, such as chord tapering and/or structural redesign of the blade cross section, would enlarge the feasible design space and likely provide significant performance improvement.

scholarly journals Low Order Harmonics Control in Stair Case Waveform by a Novel Estimation based Technique

2018 ◽  
Author(s):  
Salman Ahmad ◽  
Atif Iqbal ◽  
Imtiaz Ashraf ◽  
Sanjeevikumar Padmanaban ◽  
Mohammed Meraj
Keyword(s):  
Pulse Width Modulation ◽  
Jacobian Matrix ◽  
Initial Guess ◽  
Singularity Problem ◽  
Linear Set ◽  
Medium Voltage ◽  
Switching Losses ◽  
Voltage Application ◽  
Simulation Results ◽  
Subsequent Iteration

Few switching transitions in high power and medium voltage application of Power converters are desirable. The selective harmonics elimination (SHE) pulse width modulation offers a better quality waveform with lower switching transitions and hence lower switching losses. The SHE is a pre-programmed modulation technique where certain amounts of lower order harmonics are removed and fundamental voltage is controlled. After Fourier analysis of output waveform, a set of nonlinear transcendental equations is obtained which exhibits, multiple, unique or no solution in different range of modulation index (MI). In this paper, an iterative method based on the Jacobian estimate is proposed to solve a highly non-linear set of SHE equations. The proposed technique is easy in implementation and can solve a large number of such equations as computation of the Jacobian matrix in the subsequent iteration is estimated from the previous values.  Moreover, the proposed method also removes the singularity problem, especially for large SHE equations. High accuracy in the initial guess is also not essential for this method and can converge to the solution with any random initial guess. The computational and simulation results are given to validate the concept. The hardware result is provided to confirm the computational and simulation results.

scholarly journals Performance Improvement of Sensorless Vector Controlled Induction Motor Drive for Medium Power Applications

2019 ◽  
Vol 9 (2) ◽  
pp. 2061-2068
Keyword(s):  
Induction Motor ◽  
Performance Improvement ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Motor Drive ◽  
Induction Motor Drive ◽  
Space Vector ◽  
Torque Pulsations ◽  
Multi Level ◽  
Simulation Results

This paper deals with sensorless vector controlled induction motor in which torque pulsations are reduced with improved input of induction motor. In proposed technique two multi winding transformers are used for generation of 18 sinusoidal signals given to rectifier unit and the rectifier output given as input to 9 level multi level inverter. In this proposed technique gating signals to the inverter switches will be provided through space vector pulse width modulation which considers speed as reference. This configuration was simulated in MATLAB/Simulink.and the simulation results are presented here with improvement in reduction of THD.

scholarly journals Optimized distributed systems achieve significant performance improvement on sorted merging of massive VCF files

GigaScience ◽  
2018 ◽  
Vol 7 (6) ◽  
Author(s):  
Xiaobo Sun ◽  
Jingjing Gao ◽  
Peng Jin ◽  
Celeste Eng ◽  
Esteban G Burchard ◽  
...  
Keyword(s):  
Distributed Systems ◽  
Performance Improvement ◽  
Significant Performance

Study of Split Capacitor DAC Mismatch and Calibration in SAR-ADC

2016 ◽  
Vol 26 (01) ◽  
pp. 1750003
Author(s):  
Yun Zhang ◽  
Yiqiang Zhao ◽  
Peng Dai
Keyword(s):  
Calibration Method ◽  
Sar Adc ◽  
Calibration Error ◽  
Cmos Process ◽  
Analog To Digital ◽  
Significant Performance ◽  
Performance Deterioration ◽  
Conventional Structure ◽  
Split Capacitor ◽  
Simulation Results

Mismatch and parasitic effects of bridge capacitors in successive-approximation-register analog-to-digital converter’s (SAR-ADC) split capacitor digital-to-analog conversion (DAC) cause a significant performance deterioration. This paper presents a nonlinearity analysis based on an analytical model, and a modified calibration method utilizing a pre-bias bridge capacitor is accordingly proposed. The proposed method, which uses three-segment split capacitor DAC structure, can effectively eliminate over-calibration error caused by conventional structure. To verify the technique, a 14-bit SAR-ADC has been designed in 0.35-[Formula: see text]m 2P4M CMOS process with the PIP capacitor, and the simulation results show the method can further improve ADC performance.

Fiber nonlinearity compensation using optical phase conjugation in dispersion-managed coherent transmission systems

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jinqing Hao ◽  
Bingchen Han
Keyword(s):  
Performance Improvement ◽  
System Performance ◽  
Optical Transmission ◽  
Phase Conjugation ◽  
Fiber Amplifiers ◽  
Transmission Systems ◽  
Fiber Nonlinearity ◽  
Erbium Doped ◽  
Significant Performance ◽  
Transmission Link

Abstract In the discretely amplified transmission systems with erbium-doped fiber amplifiers, the system performance of nonlinearity-compensated optical transmission based on pre-dispersed spectral inversion (PSI) is investigated numerically. We find that PSI offers more significant performance improvement in dispersion-managed (DM) links than that in non-dispersion-managed (noDM) links. On the other hand, the DM link is more sensitive to the span offset from the center of the transmission link than noDM link. The performance difference between DM and noDM links is 1 dB if the span offset equals four spans in 20 × 90 km nonlinear transmission. Furthermore, we show that for the dispersion-managed transmission, in order to obtain the best system performance, the amount of pre-dispersion of the PSI, should be optimized over different dispersion maps.

scholarly journals A New Reservoir Operation Chart Drawing Method Based on Dynamic Programming

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3355 ◽  
Author(s):  
Zhiqiang Jiang ◽  
Yaqi Qiao ◽  
Yuyun Chen ◽  
Changming Ji
Keyword(s):  
Power Generation ◽  
Dynamic Programming ◽  
Global Convergence ◽  
Local Convergence ◽  
Reservoir Operation ◽  
Optimization Methods ◽  
Simulation Results ◽  
Conventional Methods ◽  
Drawing Method ◽  
New Reservoir

A reservoir operation chart is an important tool in guiding actual reservoir operation at present. There are mainly two kinds of methods in drawing the operation chart, i.e., conventional methods and optimization methods, but each of them has some shortcomings, such as the repeated empirical inspection and correction of conventional methods, and the sensitivity to the initial trajectories of some optimization algorithms. In view of this, based on the principle of dynamic programming (DP), this paper coupled the reservoir operation chart drawing model and the DP model, and proposed a new reservoir operation chart drawing method which has no empirical inspection and correction, no requirement for initial solution, no problem of premature convergence and local convergence. In addition, this method can guarantee the global convergence of the results to a certain extent because of the global convergence of DP. Ya Yangshan reservoir in the Li Xianjiang River of China was selected as the research object to derive the operation chart by the drawing method. The simulation results show that the proposed method in this paper presents better performance compared with the conventional method on power generation, guaranteed output, and assurance rate, especially on the latter, which has a 2.68% increase. In addition, compared with the deterministic optimization results of DP, it is found that the results of the proposed method are very close to that of deterministic DP, the differences are only 1.8 GWh (0.36% decline) and 1.6 GWh (0.32% decline). So, the validity and rationality of the proposed method are further verified by the simulation results.

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