Measurement and simulation of machine-borne vertical vibration in elevator systems

In this paper vertical vibration measurements performed on a laboratory model of an elevator system have been presented and analysed. The lab oratory model consists of a machine system that drives two rigid masses representing an el evator car and a counterweight, constrained by guide rails to move vertically through a shea ve nd hoist rope. Simultaneous measurements to record accelerations of the masses and of th e machine are conducted. The three phase current intensities and the velocity signal pro vided by the encoder are also recorded during the travels. The machine torque is computed from the c urrent intensities and the motor torque ripple is analysed. A mathematical model of the labor tory setup that includes the drive system (machine and controllers) is developed to simulate t he system response. A five-degree-offreedom lumped-parameter model of the car-counterweightsheave-rope assembly is developed. The modulus of elasticity of the rope and the friction coeffic i nts at the guide rail contact and at the machine shaft are estimated from the experimental tes ts. When simulating a travel, the measured torque ripple is added to the controller generated torque as a perturbation. The acceleration response obtained from the simulations and that one obtained in the measurements are similar in amplitude and frequency content. Both show th at e car frame vibrates particularly at those excitation frequencies close to the natu r l frequencies of the elevator system model. X. Arrasate, S. Kaczmarczyk, G. Almandoz, J.M. Abete, I. Isa sa