Abstract Joint flexibility is an important factor to consider in the robot control design if high performance is expected for the robot manipulators. In this paper, we propose an adaptive tracking control method which...
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Abstract Joint flexibility is an important factor to consider in the robot control design if high performance is expected for the robot manipulators. In this paper, we propose an adaptive tracking control method which can deal with the kinematics uncertainty and uncertainties in both link and actuator dynamics of the rigid-link flexible-joint (RLFJ) robot system. Adaptive observers are designed to avoid acceleration measurements due to the fourth-order overall system dynamics. Convergence of both end-effector tracking errors and observing errors are proven and sufficient conditions are presented to guarantee system's asymptotic stability.
The potential use of molecular computation in attacking the Data Encryption Standard (DES) is already known, but the used computing models are not autonomous and require many tedious laboratory steps to execute. In th...
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The potential use of molecular computation in attacking the Data Encryption Standard (DES) is already known, but the used computing models are not autonomous and require many tedious laboratory steps to execute. In this paper, a description of attacking DES using tile self assembly models in Θ(1) distinct tile types is given theoretically. The computation takes advantage of tiles' autonomy and the characteristic of highly distributed parallel computation. Each assembly configuration yields the ciphertext in linear time with respect to the times of the round function included in DES. The feasibility of finding the main key of DES in tile assembly models has been discussed. Analysis indicates that the tile assembly models might succeed by using a little of DNA under low error rate.
The Non-Local Means (NLM) filter uses the redundancy of information in the image to remove noise, this scheme gives some of the best results among other powerful methods such as wavelet based approaches or diffusion t...
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Auto-Disturbance Rejection controller (ADRC) has been proved to be a capable replacement of PID with unmistakable advantage in performance and practicality. But it is difficult to obtain a set of optimal parameters, f...
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Auto-Disturbance Rejection controller (ADRC) has been proved to be a capable replacement of PID with unmistakable advantage in performance and practicality. But it is difficult to obtain a set of optimal parameters, for ADRC controller has too many parameters and has no deterministic rules to compute the parameters. In this paper, Objective function is constructed based on the control system performance indexes. Combined with experienced parameters of ADRC, an invasive weed optimization algorithm (IWO) is employed to obtain a set of key parameters. The simulation results show the validity of the IWO algorithm.
Based on electromagnetic field theory, this paper derived the general expressions of time domain responses for cross-well electromagnetic logging. The emission waveform may be chosen as bipolar square wave by calculat...
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Common algorithmic problem is an optimization problem, which has the nice property that several other NP-complete problems can be reduced to it in linear time. A tissue P system with cell division is a computing model...
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Common algorithmic problem is an optimization problem, which has the nice property that several other NP-complete problems can be reduced to it in linear time. A tissue P system with cell division is a computing model which has two basic characters: intercellular communication and the ability of cell division. The ability of cell division allows us to obtain an exponential amount of cells in linear time and to design cellular solutions to computationally hard problems in polynomial time. We here present an effective solution to the common algorithmic decision problem using a family of recognizer tissue P systems with cell division.
作者:
Yangguang SunMingyue DingCollege of Computer Science
South-Central University for Nationalities Image Processing and Intelligence Control Key Laboratory of Education Ministry of China Huazhong University of Science and Technology Wuhan China College of Life Science and Technology
Image Processing and Intelligence Control Key Laboratory of Education Ministry of China Huazhong University of Science and Technology Wuhan China
A novel statistical method was proposed for boundary extraction of interested objects in this letter. The proposed method was inspired by the physical nature of quantum and the statistical property of wave function. B...
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A novel statistical method was proposed for boundary extraction of interested objects in this letter. The proposed method was inspired by the physical nature of quantum and the statistical property of wave function. By introducing the polymer representation of quantum particle and based on quantum particle motion in the gradient-based image potential field, the boundary extraction was realized in our method. Experimental results demonstrated that our method has the capability to make the boundary extraction with arbitrary initialization and topology changes possible.
Solving the optimal control problem with a free final time, such as suborbital launch vehicle (SLV) trajectory optimization with two control variables and multi-constraints ones based on particle swarm optimization (P...
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Solving the optimal control problem with a free final time, such as suborbital launch vehicle (SLV) trajectory optimization with two control variables and multi-constraints ones based on particle swarm optimization (PSO), the smoothness of control variable can not be satisfied by linear interpolation method. A novel method including some improving strategies based on PSO for trajectory optimization is proposed, named LCPSO which is a kind of Cooperate PSO based on Legendre orthogonal polynomials. An additional control variable is introduced and transcribes the original optimal problem to a problem with fixed final time, and one dimension searching method based on interval analysis is used to optimize the additional control variable. Furthermore, a theorem on how to find the boundaries of the coefficient of polynomials is proved. Compared with basic PSO, LCPSO has traits of lower dimensions and smoother control variable. An example of trajectory optimization shows the effectiveness of the LCPSO algorithm.
Speckle is a granular noise that inherently exists in all types of coherent imaging systems. This paper presents a quantitative study on five despeckling methods such as frost filter, kuan filter, speckle reducing an ...
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Speckle is a granular noise that inherently exists in all types of coherent imaging systems. This paper presents a quantitative study on five despeckling methods such as frost filter, kuan filter, speckle reducing an isotropic diffusion, homomorphic filter and wavelet filter. We select six objective evaluation parameters, such as signal-to-ratio, contrast signal-to-noise ratio, figure of merit, least absolute error, edge protection factor, signal-to-minimum mean square error ratio, to quantify the performance of these filters. The comparative study will provide some parameter comparative reference for selecting a suitable filter in the ultrasound imageprocessing.
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