This article proposes a new LOS guidance method based on position prediction, which constructs the total path deviation by predicting the future time position of ships. It can solve the problem of overshoot that is pr...
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In order to solve the problems of environment disturbances and model parameter perturbation in under actuated Underwater Vehicles (UUVs) trajectory tracking control, a Sliding mode control algorithm based on projected...
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In order to further improve the accuracy of parameter identification of ship nonlinear motion mathematical model, grey wolf optimizer-support vector regression (GWO-SVR) is embedded into the nonlinear innovation proce...
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In this work the Generalized Predictive control (GPC) is revisited in order to assess its capabilities in handling colored noise disturbances using a novel design procedure. The proposed method is investigated in a si...
In this work the Generalized Predictive control (GPC) is revisited in order to assess its capabilities in handling colored noise disturbances using a novel design procedure. The proposed method is investigated in a simulated case study of spacecraft emulation. Such emulation is proposed by combining a network-controlled quadcopter and a set of computer-based control algorithms that impose approximated spacecraft dynamics to the aerial system. The corresponding model was built upon real registered flight data. The contribution of this paper is twofold: first, we propose a novel GPC design in the colored noise case. Second, we assess the use of quadcopters to investigate spacecraft guidance and control algorithms. simulation results confirmed the proposed methodology as a possible low-budget spacecraft-emulation alternative for a future experimental setup. One of the main findings of the current investigation is that no significant enhancements coming from the use of GPC in minimizing the chattering of the control signal under the colored noise disturbance case could be observed. An important discussion on this matter and possible solutions are presented for future investigations.
Dual-rotor system is an important rotor form in rotating machinery like gas turbine engine. Its complex structure results in rich dynamical behaviors and more probability to failure. The modeling and simulation of the...
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The prediction method based on the partition of weather types has been widely used in photovoltaic prediction. Here, the temporal characteristics of PV data is studied, the physical meaning of the sequential differenc...
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With the rapid development of distributed energy resources (DERs), it is of vital importance to develop a well-designed transmission cost allocation scheme to reflect the contributions of DERs to the power system. In ...
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Future space missions will increasingly rely on the help of robotic systems and in some cases even be performed purely by fully autonomous robots. Currently, robots lack the ability to learn from their environment. Le...
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Future space missions will increasingly rely on the help of robotic systems and in some cases even be performed purely by fully autonomous robots. Currently, robots lack the ability to learn from their environment. Learning is advantageous, since it decreases engineering effort and allows the robot to adapt to specific properties of its potentially yet unknown environment. However, in space robotics machine learning is not yet used, as it introduces extra risk for safety-critical missions. In this talk, we will introduce self-supervised learning as a reliable learning method that allows robots to adapt to their environment. We have previously successfully tested this method for the navigation of autonomous drones on Earth, which showed its potential in terms of reliability for application in space. Here, we will present preliminary results from an ISS test performed with the MIT/NASA SPHERES VERTIGO satellite, which is equipped with a stereo vision system that allows it to see distances and navigate by itself in the ISS. The presented preliminary experiments were performed on October 8th 2015 on board the ISS. In the experiments, the satellite learned by itself how to see distances with a single camera. It did so by using the distance estimates from its stereo vision process as supervised learning targets. The main advantage of this learning method is that the robot becomes robust against losing the images from one of the cameras - it can then still continue to function. The main goals of the experiment were (1) data gathering, and (2) navigation on the basis of stereo vision. First the astronaut Kimya Yui moved the satellite around the Japanese Experiment Module to gather stereo vision data for learning. Subsequently, the satellite freely explored the space in the module based on its (trusted) stereo vision system and a pre-programmed exploration behavior, while simultaneously performing the self-supervised learning on board in the background. The two main goals we
Obtaining the lightning strike density along an overhead transmission line and identifying the lightning strike types are the key to evaluating the lightning protection performance and proposing reasonable protection ...
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Obtaining the lightning strike density along an overhead transmission line and identifying the lightning strike types are the key to evaluating the lightning protection performance and proposing reasonable protection schemes of transmission lines. In addition, the waveform characteristics of lightning invasion overvoltage are the basis to establish the standard on the insulation tests of power equipment. Measuring the transient process of lightning striking overhead transmission lines is the basis to carry out the work mentioned above. In this paper, a distributed measurement method of transient current on conductors caused by lightning strikes is proposed. The measuring units are installed on the field conductors of transmission lines every 30 km to obtain less-distorted transient current waveforms. In order to enable measuring units to work in field isolated environment, a power supply coil using Faraday electric-magnetic effect and a wireless communication module is designed and developed. By far, 4776 measuring units have been installed on 597 transmission lines of China's power grid. According to measured transient current waveforms, the lightning strike point can be located using the double-end or single-end travelling wave location method, and the lightning strike type can also be identified. Moreover, a novel measurement method of lightning transient voltage based on the integrated optical electric field sensor (IOEFS) is proposed. In this method, the transient voltage waveforms are inversed from space electric field waveforms measured by IOEFSs. A series of performance tests of IOEFS have been carried out. The test results indicate that the response speed can reach several nanoseconds, and the frequency response can cover 5Hz∼100MHz which is wide enough for the measurement of the lightning transient voltage. In order to test the field measurement effect, the measurement equipment is used to measure a transient voltage when a group of capacitor voltage trans
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