4,947 research outputs found
A Novel Chaotic Particle Swarm Optimization Algorithm for Parking Space Guidance
An evolutionary approach of parking space guidance based upon a novel Chaotic Particle Swarm Optimization (CPSO) algorithm is proposed. In the newly proposed CPSO algorithm, the chaotic dynamics is combined into the position updating rules of Particle Swarm Optimization to improve the diversity of solutions and to avoid being trapped in the local optima. This novel approach, that combines the strengths of Particle Swarm Optimization and chaotic dynamics, is then applied into the route optimization (RO) problem of parking lots, which is an important issue in the management systems of large-scale parking lots. It is used to find out the optimized paths between any source and destination nodes in the route network. Route optimization problems based on real parking lots are introduced for analyzing and the effectiveness and practicability of this novel optimization algorithm for parking space guidance have been verified through the application results
Sliding Mode Attitude Maneuver Control for Rigid Spacecraft without Unwinding
In this paper, attitude maneuver control without unwinding phenomenon is
investigated for rigid spacecraft. First, a novel switching function is
constructed by a hyperbolic sine function. It is shown that the spacecraft
system possesses the unwinding-free performance when the system states are on
the sliding surface. Based on the designed switching function, a sliding mode
controller is developed to ensure the robustness of the attitude maneuver
control system. Another essential feature of the presented attitude control law
is that a dynamic parameter is introduced to guarantee the unwinding-free
performance when the system states are outside the sliding surface. The
simulation results demonstrate that the unwinding phenomenon is avoided during
the attitude maneuver of a rigid spacecraft by adopting the constructed
switching function and the proposed attitude control scheme.Comment: 8 Pages, 8 figures. arXiv admin note: text overlap with
arXiv:2004.0700
Anti-Unwinding Sliding Mode Attitude Maneuver Control for Rigid Spacecraft
In this paper, anti-unwinding attitude maneuver control for rigid spacecraft
is considered. First, in order to avoid the unwinding phenomenon when the
system states are restricted to the switching surface, a novel switching
function is constructed by hyperbolic sine functions such that the switching
surface contains two equilibriums. Then, a sliding mode attitude maneuver
controller is designed based on the constructed switching function to ensure
the robustness of the closed-loop attitude maneuver control system to
disturbance. Another important feature of the developed attitude control law is
that a dynamic parameter is introduced to guarantee the anti-unwinding
performance before the system states reach the switching surface. The
simulation results demonstrate that the unwinding problem is settled during
attitude maneuver for rigid spacecraft by adopting the newly constructed
switching function and proposed attitude control scheme.Comment: 8 pages, 8 figure
Nonlinear Decoupling Sliding Mode Control of Permanent Magnet Linear Synchronous Motor Based on α-th Order Inverse System Method
AbstractIn this paper, a nonlinear dynamic decoupling controller is proposed for the permanent magnet linear synchronous motor (PMLSM) servo system to improve dynamic operating performance. Firstly, the reversibility of the PMLSM mathematical model is analyzed, and it is proved that the system is reversible. Then an inverse system method is applied to the PMLSM servo system, and it is decoupled into a linear velocity subsystem and a linear current subsystem based on the α-th order inverse system method. Considering the both ideal linear subsystems are sensitive to parameter disturbances and various disturbances, a variable rate reaching law approach based subsystem sliding mode controller for higher system stability and robustness is proposed. Finally, simulation results are provided to demonstrate the effectiveness of the proposed control method
Quantized charge-pumping in higher-order topological insulators
We study the quantized charge pumping of higher-order topological insulators
(HOTIs) with edge-corner correspondences based on the combination of the
rotation of in-plane magnetic field and the quantum spin Hall effect. A picture
of a specific charge pumping process is uncovered with the help of the
non-equilibrium Green's function method. Significantly, we demonstrate that the
quantized charge pumping current is achieved without the participation of bulk
states, and the charges move along the boundary of the sample. Furthermore, the
effects of external parameters on the pumping current is also studied. We find
that the magnitude and direction of the pumping current can be manipulated by
adjusting the coupling strength between the leads and sample. Our work deepens
the understanding of the charge pumping in HOTIs and extends the study of their
transport properties.Comment: 8 pages, 5 figure
Solving the generalized Sylvester matrix equation AV+BW=EVF via a Kronecker map
AbstractThis note considers the solution to the generalized Sylvester matrix equation AV+BW=EVF with F being an arbitrary matrix, where V and W are the matrices to be determined. With the help of the Kronecker map, some properties of the Sylvester sum are first proposed. By applying the Sylvester sum as tools, an explicit parametric solution to this matrix equation is established. The proposed solution is expressed by the Sylvester sum, and allows the matrix F to be undetermined
Vibration analysis of a beam on a moving vehicle under the road excitation with different contact models
Dynamic analysis of a beam on a moving vehicle is presented in this paper. The vehicle is simulated by a four degrees-of-freedom mass-spring system and the beam on top is supported by spring-damping systems. Two contact models named the ‘point contact’ and the ‘patch contact’ respectively, are adopted to simulate the interaction between road surface and vehicular tyres. The equation of motion of the beam-vehicle system is formulated and the dynamic response on the beam under the excitation of the irregular road surface is derived. Numerical simulations are conducted to demonstrate the influence of different factors, such as the length of the contact, the velocity of vehicle, the road condition and the bracing stiffness, etc. on the vibration level of the beam structure, which aims to provide references on the vibration problem in transporting a beam-shaped package
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