Trajectory tracking compensation for teleoperation with transmission delays

SUMMARYThe proper transmission of wave variables rather than power variables in teleoperation with time delays ensures system passivity – rendering the entire system stable, but the introduction of wave variables leads to distortion between the velocities/positions of the master and slave, and the performance deteriorates significantly with the increase of time delays. This paper presents a new compensating scheme implemented at the slave side to remove or cancel partially the distortion. The system passivity can still be maintained by tuning a properly designed low-pass filter. Compared with previous work, the main contribution of this work exists in two points: first, it is the actual velocity/trajectory of the slave rather than the reference velocity/trajectory of the slave that tracks the master one, so the quality of tracking is better and converges faster; second, the proposed compensator does not require any additional signal from the master side, minimizing the amount of data transmitted over the channel, which is very important from the practical point of view. The simulation and experiment results show that the velocity (or trajectory) tracking is significantly improved under the condition of stability, and the force presented to the user is close to the environment one, meaning a high degree of system transparency is achieved.

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Trajectory tracking control for chain-series robot manipulator: Robust adaptive fuzzy terminal sliding mode control with low-pass filter

International Journal of Advanced Robotic Systems ◽

10.1177/1729881420916980 ◽

2020 ◽

Vol 17 (3) ◽

pp. 172988142091698 ◽

Cited By ~ 1

Author(s):

Pengcheng Wang ◽

Dengfeng Zhang ◽

Baochun Lu

Keyword(s):

Trajectory Tracking ◽

Sliding Mode ◽

Sliding Mode Controller ◽

Continuous Control ◽

Terminal Sliding Mode ◽

Pass Filter ◽

Low Pass Filter ◽

Adaptive Fuzzy ◽

Low Pass ◽

Robust Adaptive

This article investigates a difficult problem which focuses on the external disturbance and dynamic uncertainty in the process of trajectory tracking. This article presents a robust adaptive fuzzy terminal sliding mode controller with low-pass filter. The low-pass filter can provide smooth position and speed signals. The fuzzy terminal sliding mode controller can achieve fast convergence and desirable tracking precision. Chattering is eliminated with continuous control law, due to high-frequency switching terms contained in the first derivative of actual control signals. Ignoring the prior knowledge upper bound, the controller can reduce the influence of the uncertain kinematics and dynamics in the actual situation. Finally, the experiment is carried out and the results show the performance of the proposed controller.

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Training Periodic Sequences Using Fourier Series Error Criterion

Neural Computation ◽

10.1162/neco.1993.5.1.115 ◽

1993 ◽

Vol 5 (1) ◽

pp. 115-131 ◽

Cited By ~ 1

Author(s):

James A. Kottas

Keyword(s):

Fourier Series ◽

Time Delays ◽

Spectral Energy ◽

Fourier Space ◽

Training Algorithm ◽

Pass Filter ◽

Low Pass Filter ◽

Periodic Sequences ◽

Periodic Input ◽

Low Pass

Training a network to learn a set of periodic input/output sequences effectively makes the network learn a mapping between amplitudes and phases in Fourier space. The spectral backpropagation (SBP) training algorithm is a different way of doing this task. It measures the Fourier series components of the output error sequences and minimizes the total spectral energy as an adaptation criterion. This approach can train not only the weights but also time delays associated with the interconnects. Furthermore, the cells can have finite bandwidth via a first-order low-pass filter. Having adaptable time delays gives the SBP algorithm a powerful way to control the phase characteristics of the network.

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Scattering and information

Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences ◽

10.1098/rsta.1970.0072 ◽

1970 ◽

Vol 268 (1185) ◽

pp. 177-200 ◽

Cited By ~ 14

Keyword(s):

Structural Information ◽

Speckle Noise ◽

Quantitative Information ◽

Sampling Interval ◽

Point Of View ◽

Partial Coherence ◽

Pass Filter ◽

Low Pass Filter ◽

Low Pass ◽

Scattering Volume

The paper discusses some aspects of scattering of electromagnetic radiation in inhomogeneous media from the point of view of information theory. A theory is developed, based on a concrete model of a typical scattering experiment, which takes into account the finiteness of the scattering volume and the coherence characteristics of the radiation; as a conclusion, the speckle noise which is superimposed over the signal is brought into evidence. More exactly, it is shown that the spurious oscillations are due to the non-vanishing character of the convolution square of the inhomogeneity distribution function at the point of truncation in the primary space. Subsequently, the structural information of scattering experiments is examined and the finite logoncontent determined. The sampling interval is established and the resolution achievable in scattering measurements is deduced; also the means by which it can be improved are examined. An analysis of the quantitative information obtainable is pursued and the desirability of filtering is suggested. Finally, the way in which the partial coherence effectively acts as a low-pass filter is studied.

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Motion Trajectory Tracking Method for Vehicle Steering Based on Dynamic Surface Control

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.220-223.1023 ◽

2012 ◽

Vol 220-223 ◽

pp. 1023-1027

Author(s):

Jun Gu ◽

Jun Fan ◽

Huan Shen

Keyword(s):

Trajectory Tracking ◽

Tracking System ◽

Lateral Position ◽

Dynamic Surface Control ◽

Dynamic Surface ◽

Pass Filter ◽

High Order Derivative ◽

Low Pass Filter ◽

Low Pass ◽

The Stability

Focus on the problem of steering trajectory tracking, a tracking control law based on dynamic surface is proposed. Other than existing methods, this paper considers combined lateral position and yaw synchronously control. The first order low pass filter is used to obtain the differential items of the lateral position and yaw, so as to eliminate the high order derivative from the final expression of the close loop law. This characteristic is very useful especially in real applications. The Lyapunov approach is employed to analysis the stability of the tracking system, and the convergence of the system is achieve. Simulation result validates the outstanding effectiveness of the proposed method for steering trajectory tracking.

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Application of Empirical Wavelet Transform in Digital Image Watermarking

Traitement du signal ◽

10.18280/ts.370517 ◽

2020 ◽

Vol 37 (5) ◽

pp. 839-845

Author(s):

Mohammad Keivani ◽

Amir Mahdi Sazdar ◽

Jalil Mazloum ◽

Akram Esvand Rahmani

Keyword(s):

Wavelet Transform ◽

Image Watermarking ◽

Low Cost ◽

Original Data ◽

Point Of View ◽

Security Requirements ◽

Pass Filter ◽

Low Pass Filter ◽

Empirical Wavelet Transform ◽

Low Pass

Nowadays, rapid growth of the Internet and digital multimedia technologies make it possible to duplicate data without any loss of quality and at a very low cost. In this regard, manipulation of documents will easily be accomplished by applying digital art and without the copyright owner's permission. To deal with situation, more diverse security requirements are introduced every day. Watermarking is considered as one of the methods used for achieving this purpose. Watermarking is focused on inserting a subtle signal between the host media data somehow it does not change the original data, but they can be extracted if necessary. They are also used as a claim for ownership of the digital effect. Various methods have been presented for watermarking so far. These methods have been developed to overcome the weaknesses of previous methods. Empirical wavelet transform is taken into account as a new method for hiding and extracting military digital images with respect to alpha composition. As such, it is resistant to noise, low pass filter and compression. Analytical studies showed that this method is more efficient than other methods from quantitative and qualitative point of view.

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Robust fuzzy sliding mode control based on low pass filter for the welding robot with dynamic uncertainty

Industrial Robot the international journal of robotics research and application ◽

10.1108/ir-04-2019-0074 ◽

2019 ◽

Vol 47 (1) ◽

pp. 111-120

Author(s):

Pengcheng Wang ◽

Dengfeng Zhang ◽

Baochun Lu

Keyword(s):

Sliding Mode Control ◽

Trajectory Tracking ◽

Sliding Mode ◽

Welding Robot ◽

Pass Filter ◽

Low Pass Filter ◽

Content Type ◽

Mode Control ◽

Dynamic Uncertainty ◽

Low Pass

Purpose Considering the external disturbances and dynamic uncertainties during the process of the trajectory tracking, this paper aims to address the problem of the welding robot trajectory tracking with guaranteed accuracy. Design/methodology/approach The controller consists sliding mode control, fuzzy control and low pass filter. The controller adopts low-pass filter to reduce the high frequency chattering control signal in sliding mode control. The fuzzy control model is used to simulate the external disturbance signal and the dynamic uncertainty signal, so that the controller can effectively restrain the chattering caused by the sliding mode control algorithm, realizing the track of the welding robot effectively and improving the robustness of the robot. Findings An innovative experiment device was adopted to realize the performance of the proposed controller. Considering the kinematic and dynamic uncertainty during the process of robot tracking, the tracking accuracy was realized within 0.3 mm. Originality/value This paper uses Lyapunov stability theory and Barbalat theorem to analyze the stability of the proposed controller.

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