Due to the characteristics of simple algorithm, low cost and small size sensor, optical flow has shown great potential in aircraft navigation, especially in GPS-denied environment. Optical flow could be used to obtain...
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Due to the characteristics of simple algorithm, low cost and small size sensor, optical flow has shown great potential in aircraft navigation, especially in GPS-denied environment. Optical flow could be used to obtain the aircraft motion information, but the existing methods cannot accurately estimate the 6-DOF motion. The purpose of this paper is to provide a state estimation method based on optical flow from forward and down looking cameras. First, make use of the optical flow distribution shape to get attitude information, and avoid using the unavailable depths by optical flow decoupling. Then, use the attitude information to eliminate the influence rotational motion has on velocity estimation, and compute the depths of feature points captured by down looking camera in a 3D motion, to simplify the optical flow motion field estimation model, and as a result reduce computational complexity. Simulation results show the method presented in this paper is accurate and robust.
The smart lighting control in the new commercial studios and smart homes not only provides the user with better control but also enhances the aesthetic value of the place. This control is achieved by profiling and con...
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The smart lighting control in the new commercial studios and smart homes not only provides the user with better control but also enhances the aesthetic value of the place. This control is achieved by profiling and controlling the lights by using user defined lighting conditions. One possible and a neat way is by using NFC Tags loaded with the user profile details and also the intensity or color details and interface it with the control board that adjust the intensity and color by a simple pulse width modulation and using RGB led matrix panels as lighting elements. The PWM technique varies the light intensity as per the width of the triggering pulse and the desired color profile can be obtained by combining three main colors that is red, green and blue in different proportions. The paper presents an approach to the profiling and control done using Near Field Communication (NFC) technology which is based on short range radio communication. Since most of the new smart phones are also coming with NFC chip enabled thus the profiling can be made mobile and even more personalized. The paper uses a NFC reader on base control board to read a profile from a rewritable tag. So when a Tag is tapped with the base board, the information from the NFC tag is read and sent to microcontroller where the particular light profile is selected from a user defined list of light profiles.
This paper investigates the problem of feedback control design with vibration suppression for a flexible air-breathing hypersonic vehicle(FAHV).FAHV includes intricate coupling between the engine and flight dynamics,a...
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This paper investigates the problem of feedback control design with vibration suppression for a flexible air-breathing hypersonic vehicle(FAHV).FAHV includes intricate coupling between the engine and flight dynamics,as well as complex interplay between flexible and rigid modes,which results in an intractable system for the control *** this paper,a longitudinal model,which is described by a coupled system of ordinary diferential equations(ODEs)and partial diferential equations(PDEs),is ***,a linearized ODE model for the rigid part is established around the trim condition,while vibration of the fuselage is described by ***,based on the Lyapunov direct method,a control law via ODE state feedback and PDE boundary output feedback is designed for the system such that the closed-loop exponential stability is ***,simulation results are given to illustrate the efectiveness of the proposed design method.
A new composite nonlinear predictive control(NPC) method based on finite-time disturbance observer is proposed for Mars entry drag trajectory tracking. The composite controller uses nonlinear predictive control strate...
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ISBN:
(纸本)9781467374439
A new composite nonlinear predictive control(NPC) method based on finite-time disturbance observer is proposed for Mars entry drag trajectory tracking. The composite controller uses nonlinear predictive control strategy in a feedback regulation way to obtain desired tracking performance and uses the disturbance estimation based on finite-time disturbance observer(FTDO)to compensate uncertainty in a feedforward way. The proposed guidance law not only compensates the matched disturbance but also the mismatched disturbance. The drag tracking error is also guaranteed to converge to 0 even when the disturbance is time-varying and related with states.
A graphics-based information model of substation and dispatch center is proposed in this *** model adopts the integrative organization of the graphic-model,combining model information with graphic *** combined informa...
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A graphics-based information model of substation and dispatch center is proposed in this *** model adopts the integrative organization of the graphic-model,combining model information with graphic *** combined information is included in electrical equipment ***,consistency of power grid model information and graphic information is *** graphics-based information model unifies the requirements of IEC61850 standard and IEC61970 standard,which can support collaborative modeling of substation and dispatch *** model,CIM model and SVG graphic can be derived respectively from the graphics-based information *** promotes the unity of the transformer substation standard and dispatch center model standard.
In this paper, sensorless speed control of permanent magnet synchronous motor (PMSM) with an Extended Kalman Filter (EKF) based observer is performed. The general model of the PMSM and EKF algorithm are presented. Sim...
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ISBN:
(纸本)9781467379120
In this paper, sensorless speed control of permanent magnet synchronous motor (PMSM) with an Extended Kalman Filter (EKF) based observer is performed. The general model of the PMSM and EKF algorithm are presented. Simulation studies are carried out using MATLAB/Simulink, in order to explore effectiveness and usability of EKF in sensorless PMSM drive for washing machine applications. In order to investigate performance of proposed system in real conditions, real torque profile of a washing machine is used. Simulation results illustrate that the proposed system is quite effective for washing machine applications and robust against variations of motor parameters.
This paper proposes an economical method that the phase currents can be measured and reconstructed by means of the leg-shunt resistors in the 3-leg 2-phase vector-controlled inverter for 2-phase induction motor. In ge...
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Dynamic clustering provides a scalable and energy efficient solution for data transmission in wireless sensor *** the fact that the cluster reorganization can not solve the problem of imbalanced energy consumption in ...
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ISBN:
(纸本)9781479970186
Dynamic clustering provides a scalable and energy efficient solution for data transmission in wireless sensor *** the fact that the cluster reorganization can not solve the problem of imbalanced energy consumption in the inter-cluster communication,we propose an adaptive routing strategy for cluster-based wireless sensor networks(ARC).The goal of ARC is to balance the energy consumption of nodes by adaptively controlling the modes of intercluster *** ARC,an adaptive energy threshold and a tunable cost function are designed for cluster heads to make routing *** results demonstrate that ARC effectively balances the energy consumption in the inter-cluster communication,and hence improves the energy efficiency and prolongs the network lifetime.
According to the tactical requirements of unmanned aerial vehicle (UAV) for tracking target and avoiding obstacle in complex dynamic environment, a three-dimensional (3D) real-time path planning method is proposed by ...
According to the tactical requirements of unmanned aerial vehicle (UAV) for tracking target and avoiding obstacle in complex dynamic environment, a three-dimensional (3D) real-time path planning method is proposed by combing the improved Lyapunov Guidance Vector Field (LGVF), the Interfered Fluid Dynamical System (IFDS) and the strategy of varying receding-horizon optimization from Model Predictive control (MPC). First, in order to track the moving target in 3D environment, the LGVF method is improved by introducing flight height into the traditional Lyapunov function , and the generated velocity can guide UAV converge gradually to the limit cycle in horizontal plane and the optimal height in vertical plane. Then, the IFDS method imitating the phenomenon of fluid flow is utilized to plan the collision-free path. To achieve the mission of tracking moving target and avoid static or dynamic obstacle at the same time, the guidance vector field by LGVF is taken as the original fluid of IFDS. As the fluid system still remains stable under the influence of obstacles, the disturbed streamline from the interfered fluid can be regarded as the planned path. Third, as the quality of route is mainly influenced by the repulsive and tangential parameters of IFDS, the real-time suboptimal route can be planned by the varying receding-horizon optimization according to the predicted motion. The experimental results prove that the proposed hybrid method is applicable to various dynamic environments.
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