Due to the influencing factors, such as irregularity of guide, piston wind excitation in the hoistway, and uncertain swinging of hoisting rope during the operation of high-speed traction elevator, car will produce dramatic horizontal vibration. With the purpose of suppressing this vibration effectively, the active car shock absorber is designed with linear motor, and a five-degrees-of-freedom space vibration model of the car is established and, subsequently, its state space equation is derived. For the uncertainty external excitation in the car system, the back propagation neural network proportional–integral–derivative controller with linear prediction model is designed for the intelligent active control of the vibration of the car, and simulation analysis is carried out with MATLAB/Simulink. The result shows that the active shock absorber designed in this study can effectively suppress the horizontal vibration of high-speed elevator car, better than traditional proportional–integral–derivative controller. This study has opened up a new idea of high-speed elevator vibration damping method, and is of important referential significance for the field of active control of car vibration.
For a super high-speed elevator running in a hoistway, it will encounter air flows at high speed. The transverse force and pitching moment generated by the air intensify the transverse vibration of the elevator. In this paper, by fully considering the guide rail excitation and air disturbance, the transverse vibration of a super high-speed elevator under different working conditions is examined. Based on the Lagrange principle, a four degree-of-freedom (DOF) model is adopted for the transverse vibration of the elevator. Combined with computational fluid dynamics (CFD), the effects of various parameters corresponding to different working conditions on the aerodynamic forces acting on the transverse surfaces (the surfaces facing the guide rail) of the car is analyzed. Finally, the Newmark-[Formula: see text] method is employed to analyze the effect of air disturbances on the transverse vibration acceleration of the car under different working conditions. The results show that when the car is symmetrically positioned, the aerodynamic characteristics on both transverse surfaces of the car also appear to be symmetric. The operating speed and the distance between the car’s transverse surface and the hoistway wall (DCH) have a minor effect on the transverse vibration of the car, and the car is basically in a state of forced balance in the transverse direction. However, once the car deviates from the symmetric position, the balance will be violated, and the transverse resultant force and moment of the car will increase with the increase in the deviation amount. Among all these factors, the influence of the rotation angle on the elevator’s vibration acceleration is the most significant.
With the increase of elevator running speed, the influence of aerodynamic force on elevator becomes more and more obvious, and the impact is also increasing gradually. In this paper, the Computational Fluid Dynamic numerical simulation method is used to simulate and analyse the aerodynamic characteristics of elevator car under the influence of different operating speed and distance from side of car to hoistway wall by establishing full-scale model of elevator and hoistway. The results show that when the car is in a symmetrical position, the aerodynamic characteristics on both sides always show obvious symmetry. With the decrease of distance from side of car to hoistway wall and the operating speed of the car, the flow field around the car changes intensified, and the aerodynamic forces on the side of the car will also increase significantly.
To reduce the aerodynamic load of super high-speed elevators, in this paper, the coefficient of drag [Formula: see text] and the coefficient of yawing moment [Formula: see text] of the elevator are selected as optimization objectives for the optimization of the air rectification cover (ARC) shape. The elliptic curve method was used to build the parametric model of the ARCs, six design variables were selected, and the design space of the ARC was determined. With the optimal Latin hypercube design method, the training points were selected, and the computational fluid dynamics numerical simulation was conducted to calculate the corresponding responses. Then, the relationship between the design variables and the responses was analyzed. The radial basis function (RBF) surrogate model of the relationship between the design variables and responses was constructed. Finally, the non-dominated sorting genetic algorithm-II (NSGA-II) was employed to optimize the shape of the ARC. The results show that the [Formula: see text] and [Formula: see text] decrease by 16.51% and 60.92%, respectively, compared with the unoptimized ARC, indicating that the ARC designed in this paper is optimized and can effectively reduce the aerodynamic load. Furthermore, among all the design variables, the bluntness of the ARC in the [Formula: see text]-direction has the most significant effect on the aerodynamic load, and the height of the ARC ([Formula: see text] and [Formula: see text]) has the second most significant effect on the aerodynamic load of elevators.
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