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Rapid development of bike-sharing systems has brought people enormous convenience during the past decade. On the other hand, high transport flexibility comes with dynamic distribution of shared bikes, leading to an unbalanced bike usage and growing maintenance cost. In this paper, we consider to rebalance bicycle utilization by means of directing users to different stations. For the first time, we...
This paper presents a passive fault tolerant control for the satellite attitude systems with unknown external disturbance and actuator fault. Firstly, the nonlinear satellite attitude dynamics with actuator fault are given. Then, under the framework of backstepping control, a PI control with adaptive tuning gain is designed, which aims to provide added robustness in the presence of large and fast...
To improve the safety of EV battery replacement stations, grey correlation and grey entropy evaluation models are established based on normalized processing evaluation objects and the ideal object, and the system safety influence degree is evaluated according to different weights evaluation objects in the models. For the battery replacement stations safety evaluation, the safety assessment model is...
In order to improve the electric car battery safety early warning ability and decrease the safe accident of electric vehicle charging, the electric vehicle charging safety factors are analyzed, the security early warning index selection ways and methods are studied, and a security early warning evaluation index system is set, the evaluation method of weight for safety index is discussed. Besides,...
Solving electromagnetic (EM) scattering by very slim conducting objects could be challenging in integral equation approach because the polarized current density tends to be singular near the edges of such objects and many low-quality meshes exist when discretized. Traditionally, the problem is formulated based on electric field integral equation (EFIE) by approximating the objects as two-dimensional...
Actuator fault of a multicopter Unmanned Aerial Vehicle (UAV) may lead to a dangerous flight, and even damage the UAV. To ensure the flight safety in case of unpredictable actuator fault, many active fault tolerant control methods are studied in the last decade. An active fault tolerant method of a multicopter includes a fault detection, isolation and reconstruction (FDIR) scheme and a control allocation...
When input dimension of BP neural network increased, the structure of BP neural network will become especially complex and it is vulnerable to fall into local optimum in the training process. Therefore, a new algorithm of BP neural network optimized by rough set (RS) and mind evolutionary algorithm (MEA) is proposed. RS theory was used as the front-end date processing system to achieve attribute reduction,...
The shuffle transfer pattern is widely adopted in today's cluster computing applications and the completion time of each group of transmissions directly affects application performance. Because of the restriction on the number of concurrent threads and the TCP Incast problem, the randomized data fetching strategy is widely employed in this kind of communication in practice. In this paper, to assess...
Increasing dynamics of electrical loads presents uncertainty and hence new challenges for power grid controls and optimization. In economic dispatch control (EDC) for minimizing generation cost, demand reporting by customers is a promising approach for managing the uncertainty, but it raises important privacy concerns. Adding random noise to aggregate queries of demand reports can provide differential...
In this paper, an active fault tolerant controller is designed for a class of nonlinear flight control systems with bounded external disturbances and unknown actuator effectiveness loss faults. Firstly, the nonlinear flight control system models of an aircraft are given. When some actuators occur the unknown loss of effectiveness faults, the faulty flight control systems is further established. To...
With the rapid advancement of mobile devices and crowdsourcing platforms, spatial crowdsourcing has attracted much attention from various research communities. A spatial crowdsourcing system periodically matches a number of locationbased workers with nearby spatial tasks (e.g., taking photos or videos at some specific locations). Previous studies on spatial crowdsourcing focus on task assignment strategies...
The estimation of carrier parameters is the key for coherent reception. FFT-based methods which have lower complexity, larger frequency regions and attractive performance have been widely used in practice. However, there is still much room for improvement for these traditional estimators. For example, the MSEs of traditional estimators would fluctuate dramatically while frequency varies, and they...
This paper proposes a direct power control (DPC) strategy for the grid-connected voltage source inverter (VSI) without phase-locked loop (PLL) under harmonically distorted voltage conditions. A virtual angular is employed instead of the voltage vector angular acquired by the PLL. The second-order vector integrator (SOVI) is integrated with the DPC to implement two different control targets of smooth...
In order to estimate the state of charge (SOC) of LiFePO4 battery more accurately, an improved Extended Kalman Filter (EFK) algorithm is proposed to estimate the parameters in the least squared identification model. A second-order RC equivalent circuit is used as the battery model, and an additive term is introduced into the state equation for real-time parameter update. Besides, a fuzzy controller...
Electric bikes (e-bikes) are booming in China, providing a flexible and energy-efficient trip mode for people all around the country. However, the problems such as traffic accidents and disrupting social order caused by e-bikes bring much worry to the government operators. And the behavior of e-bike users also attracts the sociological researchers' interest due to their characteristics (e.g. lower...
Geographical limitations have always been a major concern in Singapore. As demand for a more efficient transport system to accommodate the rising population increases, alternatives such as underground spaces have been explored and made available. The most recent example is the newly introduced Downtown Line which have exploited the spaces Singapore can offer underground. With the transport lines built...
Rapid development of extremely-low voltage high current MOSFETs allows reversing common design principles to explore new applications, such as battery powered traction drives. This enables the usage of multi-phase single-turn stator windings which can achieve a copper fill factor close to one. This paper briefly describes the proposed 2V, 1.1kW MOSFET commutated 13-phase permanent magnet DC motor...
This paper presents the high frequency noise characterization of bipolar and MOSFET devices over temperature. The device noise parameter calculation based on Y-parameters is utilized to compare with the results from measurement over temperature. Based on the calculated and measured results, this paper will discuss the device model parameters which impact the temperature dependence of noise properties...
Lithium-ion batteries play an important role in electric vehicles. Accurate and robust estimation of their state-of-charge is crucial for the efficient and safe operation of electric vehicles. To improve the accuracy and robustness of the estimation approach, an adaptive PI observer aim for state-of-charge estimation and parameters update simultaneously is proposed. Lyapunov stability analysis is...
In this paper, an inter satellite link handover management scheme based on link remaining time (HM-LRT) is proposed. Since the satellites move in a regular pattern, the remaining time of inter satellite links going down can be predicted. Based on link remaining time and other information, our link handover management scheme changes the data transmission routes to prevent data packets from going into...
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