scholarly journals Vision Positioning-Based Estimation Method and Its Simulation Studies on State of Underwater Manipulator

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Junli Wang ◽  
Shitong Wang ◽  
Wenhao Leng
Keyword(s):  
Automatic Control ◽  
Estimation Method ◽  
Industrial Robots ◽  
Control Methods ◽  
Positioning Error ◽  
Simulation Studies ◽  
Joint Angles ◽  
Underwater Manipulator ◽  
Vision Positioning ◽  
Work Class

Work class remote operated vehicles (ROVs) are generally equipped with underwater manipulators and are widely used in underwater intervention and maintenance tasks. As the load of underwater operation is relatively heavy, most commercial underwater manipulators are hydraulically actuated and are not equipped with any sensor for joint angles to keep their architectures compact. Therefore, the automatic control methods widely used in industrial robots cannot be simply applied to underwater manipulators. In this paper, an estimation method on joint angles of manipulator is presented, in which several markers are arranged on the arm links and positioned from the corresponding cameras; consequently, the joint angles of the manipulator are estimated. The simulation results show that under typical optical vision positioning error (RMS: 5 mm), the positioning error of the end effector can be estimated as about 10 mm (RMS), which means that the proposed estimation method is feasible for the state estimation for automatic control of underwater manipulators.

scholarly journals Research of Calibration Method for Industrial Robot Based on Error Model of Position

2021 ◽  
Vol 11 (3) ◽  
pp. 1287
Author(s):  
Tianyan Chen ◽  
Jinsong Lin ◽  
Deyu Wu ◽  
Haibin Wu
Keyword(s):  
Coordinate System ◽  
Industrial Robot ◽  
Calibration Method ◽  
Error Model ◽  
Position Error ◽  
Industrial Robots ◽  
Positioning Error ◽  
Robot Position ◽  
General Measurement ◽  
Parameter Error

Based on the current situation of high precision and comparatively low APA (absolute positioning accuracy) in industrial robots, a calibration method to enhance the APA of industrial robots is proposed. In view of the "hidden" characteristics of the RBCS (robot base coordinate system) and the FCS (flange coordinate system) in the measurement process, a comparatively general measurement and calibration method of the RBCS and the FCS is proposed, and the source of the robot terminal position error is classified into three aspects: positioning error of industrial RBCS, kinematics parameter error of manipulator, and positioning error of industrial robot end FCS. The robot position error model is established, and the relation equation of the robot end position error and the industrial robot model parameter error is deduced. By solving the equation, the parameter error identification and the supplementary results are obtained, and the method of compensating the error by using the robot joint angle is realized. The Leica laser tracker is used to verify the calibration method on ABB IRB120 industrial robot. The experimental results show that the calibration method can effectively enhance the APA of the robot.

scholarly journals An Alternative Promotion Time Cure Model with Overdispersed Number of Competing Causes: An Application to Melanoma Data

Mathematics ◽  
2021 ◽  
Vol 9 (15) ◽  
pp. 1815
Author(s):  
Diego I. Gallardo ◽  
Mário de Castro ◽  
Héctor W. Gómez
Keyword(s):  
Estimation Method ◽  
Selection Criterion ◽  
Likelihood Method ◽  
Simulation Studies ◽  
Cure Rate ◽  
Nested Models ◽  
Proposed Model ◽  
The Em Algorithm ◽  
Competing Causes ◽  
The One

A cure rate model under the competing risks setup is proposed. For the number of competing causes related to the occurrence of the event of interest, we posit the one-parameter Bell distribution, which accommodates overdispersed counts. The model is parameterized in the cure rate, which is linked to covariates. Parameter estimation is based on the maximum likelihood method. Estimates are computed via the EM algorithm. In order to compare different models, a selection criterion for non-nested models is implemented. Results from simulation studies indicate that the estimation method and the model selection criterion have a good performance. A dataset on melanoma is analyzed using the proposed model as well as some models from the literature.

Dynamic Anti-Saturation Integral Controller Used in Time-Varying Delay System

2011 ◽  
Vol 467-469 ◽  
pp. 766-769
Author(s):  
Gui You Pu ◽  
Ge Wen Kang
Keyword(s):  
Variable Structure ◽  
Delay System ◽  
Time Varying ◽  
Control Methods ◽  
Simulation Studies ◽  
Motor Speed ◽  
Intelligent Controller ◽  
Time Varying Delay ◽  
Integral Controller ◽  
Varying Delay

Systems with large variable delay, traditional control methods can’t performance well. In this paper, a controller combined with the human-simulated intelligent controller (HSIC) and newly dynamic anti-saturation integral controller, is used in the time-varying delay motor speed control. Simulation studies show, there is no chatter in this controller which is always in norm variable structure controller and this method reaches good performance in the time-varying delay system.

Finding Features of Positioning Error for Large Industrial Robots Based on Convolutional Neural Network

2021 ◽  
Author(s):  
Daiki Kato ◽  
Kenya Yoshitugu ◽  
Naoki Maeda ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama ◽  
...  
Keyword(s):  
Neural Network ◽  
Convolutional Neural Network ◽  
Production Systems ◽  
Industrial Robot ◽  
Three Dimensional ◽  
Industrial Robots ◽  
Numerical Control ◽  
Robot Motion ◽  
Positioning Error ◽  
End Effector

Abstract Most industrial robots are taught using the teaching playback method; therefore, they are unsuitable for use in variable production systems. Although offline teaching methods have been developed, they have not been practiced because of the low accuracy of the position and posture of the end-effector. Therefore, many studies have attempted to calibrate the position and posture but have not reached a practical level, as such methods consider the joint angle when the robot is stationary rather than the features during robot motion. Currently, it is easy to obtain servo information under numerical control operations owing to the Internet of Things technologies. In this study, we propose a method for obtaining servo information during robot motion and converting it into images to find features using a convolutional neural network (CNN). Herein, a large industrial robot was used. The three-dimensional coordinates of the end-effector were obtained using a laser tracker. The positioning error of the robot was accurately learned by the CNN. We extracted the features of the points where the positioning error was extremely large. By extracting the features of the X-axis positioning error using the CNN, the joint 1 current is a feature. This indicates that the vibration current in joint 1 is a factor in the X-axis positioning error.

scholarly journals A survey of automatic control methods for liquid-propellant rocket engines

2019 ◽  
Vol 107 ◽  
pp. 63-84 ◽  
Author(s):  
Sergio Pérez-Roca ◽  
Julien Marzat ◽  
Hélène Piet-Lahanier ◽  
Nicolas Langlois ◽  
François Farago ◽  
...  
Keyword(s):  
Automatic Control ◽  
Rocket Engines ◽  
Control Methods ◽  
Liquid Propellant ◽  
Propellant Rocket

scholarly journals Optical Enhancement of Exoskeleton-Based Estimation of Glenohumeral Angles

2016 ◽  
Vol 2016 ◽  
pp. 1-20 ◽  
Author(s):  
Camilo Cortés ◽  
Luis Unzueta ◽  
Ana de los Reyes-Guzmán ◽  
Oscar E. Ruiz ◽  
Julián Flórez
Keyword(s):  
Estimation Method ◽  
Position Estimation ◽  
Accurate Estimation ◽  
Joint Angles ◽  
Estimation Errors ◽  
Marker Position ◽  
Human Movements ◽  
Posture Estimation ◽  
Kinematic Models ◽  
Method Accuracy

In Robot-Assisted Rehabilitation (RAR) the accurate estimation of the patient limb joint angles is critical for assessing therapy efficacy. In RAR, the use of classic motion capture systems (MOCAPs) (e.g., optical and electromagnetic) to estimate the Glenohumeral (GH) joint angles is hindered by the exoskeleton body, which causes occlusions and magnetic disturbances. Moreover, the exoskeleton posture does not accurately reflect limb posture, as their kinematic models differ. To address the said limitations in posture estimation, we propose installing the cameras of an optical marker-based MOCAP in the rehabilitation exoskeleton. Then, the GH joint angles are estimated by combining the estimated marker poses and exoskeleton Forward Kinematics. Such hybrid system prevents problems related to marker occlusions, reduced camera detection volume, and imprecise joint angle estimation due to the kinematic mismatch of the patient and exoskeleton models. This paper presents the formulation, simulation, and accuracy quantification of the proposed method with simulated human movements. In addition, a sensitivity analysis of the method accuracy to marker position estimation errors, due to system calibration errors and marker drifts, has been carried out. The results show that, even with significant errors in the marker position estimation, method accuracy is adequate for RAR.

scholarly journals Experimental verification and stability state space analysis of CLL–T series parallel resonant converter with fuzzy controller

2012 ◽  
Vol 63 (6) ◽  
pp. 365-372
Author(s):  
Chinnadurai Nagarajan ◽  
Muthusamy Madheswaran
Keyword(s):  
State Space ◽  
Closed Loop ◽  
Fuzzy Controller ◽  
Voltage Regulation ◽  
Control Methods ◽  
Simulation Studies ◽  
Resonant Converter ◽  
Space Technique ◽  
The Stability ◽  
Steady State Performance

This paper presents a closed loop CLL-T (capacitor inductor inductor) series parallel resonant converter (SPRC) has been simulated and the performance is analyzed. A three element CLL-T SPRC working under load independent operation (voltage type and current type load) is presented in this paper. The stability and AC analysis of CLL-T SPRC has been developed using state space technique and the regulation of output voltage is done by using Fuzzy controller. The simulation study indicates the superiority of fuzzy control over the conventional control methods. The proposed approach is expected to provide better voltage regulation for dynamic load conditions. A prototype 300 W, 100 kHz converter is designed and built to experimentally demonstrate, dynamic and steady state performance for the CLL-T SPRC are compared from the simulation studies.

Semi-Parametric Statistical Model for Extreme Value Statistical Models and Application in Automatic Control

2014 ◽  
Vol 680 ◽  
pp. 455-458
Author(s):  
Yu Han
Keyword(s):  
Parameter Estimation ◽  
Automatic Control ◽  
Statistical Models ◽  
Estimation Method ◽  
Extreme Value Distribution ◽  
Extreme Value ◽  
Value Distribution ◽  
Vector Model ◽  
Extreme Statistics ◽  
The Impact

The frequency that extreme events appear in the life is low,but once it appears,the impact will be significant; many scholars have conducted in depth research and found that statistical theory of extreme value. The theory of extreme statistics plays a more and more important role in many fields such as automatic control, assembly line etc. This paper,makes an in-depth research towards the characteristics and parameter estimation of the extreme value statistical models,as well as the application,mainly analyzes the Bayes parameter estimation method of extreme value distribution,the extreme value distribution theory and Copula function random vector model.

Series of New Local Ramp Metering Strategies: Emmanouil Smaragdis and Markos Papageorgiou

2003 ◽  
Vol 1856 (1) ◽  
pp. 74-86 ◽  
Author(s):  
Emmanouil Smaragdis ◽  
Markos Papageorgiou
Keyword(s):  
Automatic Control ◽  
Ramp Metering ◽  
Control Methods ◽  
Feedback Strategy ◽  
Macroscopic Simulation ◽  
Street Traffic ◽  
Upstream Flow ◽  
New Strategies

The local ramp metering strategy ALINEA is the only available feedback strategy that is based on powerful and robust automatic control methods. A number of modifications and extensions were proposed to address specific issues and needs not covered by ALINEA. More specifically, the following new local ramp metering strategies are presented: FL-ALINEA is a flow-based strategy, UP-ALINEA is an upstream-occupancy-based version, and UF-ALINEA is an upstream-flow-based strategy. X-ALINEA/Q is a combination of any of the preceding strategies with efficient rampqueue control to avoid interference with surface street traffic. The new local ramp metering strategies are discussed with respect to their features, their limitations, and their relation to available strategies. Macroscopic simulation investigations demonstrate the capabilities and limitations of the new strategies.

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