A new control device is proposed to isolate an elevator cabin from irregularities on a guide rail. The device consists of two rotary electric motors with disks and eccentric masses. One motor produces torque to rotate the eccentric mass according to the command signals from the controller for horizontal control, while the other rotates the mass to eliminate the unwanted vertical force. To design the optimal controller to reduce the horizontal vibration of the cabin, the dynamics of the cabin, including the proposed control device, are described by a linear equation. The performance of the proposed control system is examined through numerical simulations taking into consideration the nonlinear characteristics of the rotating masses, which are neglected in designing the controller, and through experiments with a miniature elevator cabin carrying the proposed actuator. The results indicate the proposed control device reduces the horizontal vibration without producing the unwanted vertical vibration.

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When elevators travel at high speed, horizontal vibrations of the car tend to occur due to guide rail deformations, deteriorating ride comfort. Therefore, several active control systems have been developed to reduce these vibrations. These systems consist of six actuators, which independently move the guide rollers. To reduce costs and installation time, it is necessary to develop a system with a minimum number of actuators and a simplified controller. We developed a system with only three actuators. The controller incorporates an H-infinity control design method for maintaining stability of the system when there is a change in load. Furthermore, from a practical point of view, it is important to reduce the order of the controller so that the time for on-site parameter tuning can be reduced. Therefore, we reduced the H-infinity controller to a P controller. We demonstrated that the maximum amplitude of vibrations of a car with active control system can be reduced to almost half the vibration amplitude without control.

When elevators travel at high speed, horizontal vibrations of the car tend to be set up by guide rail deformation.Therefore, it is important to identify the deformation accurately to improve ride quality. In this paper, we discuss a method for estimating the rail deformation by an inverse transfer function and operational acceleration data. The acceleration data indicates the vibration caused by both the rail deformation and external forces acting on the car, that is, the rope sway and wind pressure excite the car directly when it is moving by a counter weight. To identify the rail deformation from these data accurately, we propose an elevator model that has guide levers and a car. Moreover, the estimation error occurs when accelerometers are installed inaccurately. To avoid this error, the weighting function based on the modal vector is also introduced. The validity of the method is shown by the simulations and experiments.

Several active suspension systems have been developed to improve the ride quality of high speed elevators. However, none of these systems consider suppressing multi modal vibrations when a car moves over the bumps of a guide rail. We propose a structural design of the car that considers controllability and maintains a high performance while reducing vibrations with minimum actuators. The stiffness of the roller guides is designed to minimize the difference of the two phases corresponding to translational and rotational modes: specifically, the lower guide should be twice as stiff as the upper one. Experimental results showed that the proposed system can suppress vibration much more effectively compared to the conventional method using the closed-loop transfer function. The results of time response analysis and experiments also showed that the proposed structure enables a much higher control performance than the conventional one.