To provide Quality of Service (QoS) guarantees in open and unpredictable environments, the utilization control problem is defined to keep the processor utilization at the schedulable utilization bound, even in the fac...
详细信息
ISBN:
(纸本)9781605584706
To provide Quality of Service (QoS) guarantees in open and unpredictable environments, the utilization control problem is defined to keep the processor utilization at the schedulable utilization bound, even in the face of unpredictable and/or varying task execution times. To handle the end-to-end task model where each task is comprised of a chain of subtasks distributed on multiprocessors, researchers have used Model Predictive control (MPC) to address the Multiple-Input, Multiple-Output (MIMO) control problem. Although MPC can handle a limited range of model uncertainties due to execution time estimation errors, the system may suffer performance deterioration or even become unstable if the actual task execution times are much larger than their estimated values. In this paper, we present an online adaptive optimal control approach using Recursive Least Squares (RLS) based model estimator plus Linear Quadratic (LQ) optimal controller. We use simulation experiments to demonstrate the effectiveness of our controller compared withthe MPC-based controller. Copyright 2008 ACM.
the scope of the paper is the strange behavior of direct torque controlled (DTC) induction machine (IM) resulting from the nonlinearity of hysteresis comparators. A piecewise-defined, non-stroboscopic, discrete-time P...
详细信息
the scope of the paper is the strange behavior of direct torque controlled (DTC) induction machine (IM) resulting from the nonlinearity of hysteresis comparators. A piecewise-defined, non-stroboscopic, discrete-time Poincare map can be constructed for the system. the movement of the two controlled state variables, the stator flux linkage and the electric torque, within the hysteresis loops had to be determined from switch to switch. this complex Poincare map takes into account the fast switching operations of the voltage source converter (VSC). Periodic, subharmonic, chaotic and intermittent chaotic states along a special bifurcation series caused by discontinuity of the Poincare mapping function were detected. In order to give a better insight into the system operation, a one-dimensional piecewise linear map is developed, numerous subharmonic states were analyzed.
Pattern formation is one of typical problems in the field of multi-robot cooperation. It can be applied to complex application scenarios such as region coverage and path exploration. Compare to traditional multi-robot...
详细信息
Pattern formation is one of typical problems in the field of multi-robot cooperation. It can be applied to complex application scenarios such as region coverage and path exploration. Compare to traditional multi-robot coordination algorithm, the method based on swarm robots to solve the issue of pattern formation has better scalability and dynamic adaptability and robustness. In this demo, we propose a scalable algorithm using a modified gradient descent technique which allows a swarm of robots to form a letter, such as `A'. In this demo, we verify our algorithm through experimentation in a team of self-organized robots, in which communication with each other is through Zigbee network.
In this paper a new and efficient algorithm to solve a closed-form direct kinematics solution of the general 6-6 planar Stewart platform is presented. the main idea is to compute the reduced Groebner basis under degre...
详细信息
ISBN:
(纸本)9781424447947
In this paper a new and efficient algorithm to solve a closed-form direct kinematics solution of the general 6-6 planar Stewart platform is presented. the main idea is to compute the reduced Groebner basis under degree lexicographic ordering for the closed-form equations by using computer algebra firstly. Secondly, select 10 Groebner bases from the obtained 41 ones and construct a 10times10 Sylvester's matrix, which is relatively small in size. A 20th degree univariate equation is obtained from the determinate of the matrix and all 40 sets closed-form direct kinematics solutions are obtained. the proposed algorithm is simple and reduces greatly the computation burden than the existed methods. the process also shows that there exist many different resultants that will lead to the same univariate equation. the same results can be obtained by using the continuation method. Finally a numerical example is given to verify the algorithm and its results without extraneous roots agree withthe original equations.
the most common approach among researchers is to implement cryptographic techniques and methods to provide a secure and reliable way to transmit sensitive information. this paper proposes a steganographic embedding al...
详细信息
ISBN:
(数字)9798331532178
ISBN:
(纸本)9798331532185
the most common approach among researchers is to implement cryptographic techniques and methods to provide a secure and reliable way to transmit sensitive information. this paper proposes a steganographic embedding algorithm based on Circle Map and Modified Rotation Equations. Audio files randomly selected from the Internet are used for the purpose of the study. Messages of different sizes were embedded in them using the proposed steganographic embedding algorithm. the accumulated database of more than 200 containers and stegofiles was analyzed using the most common steganalysis methods. From the analyses, it can be clearly seen that the proposed method of steganographic embedding in audio containers provides a very high level of security in the transmission of hidden information.
暂无评论