Identification of Two-Mass Mechanical Systems Using Torque Excitation: Design and Experimental Evaluation

Abstract

This paper deals with methods for parameter estimation of two-mass mechanical systems in electric drives. Estimates of mechanical parameters are needed in the start-up of a drive for automatic tuning of model-based speed and position controllers. A discrete-time output error (OE) model is applied to parameter estimation. The resulting pulse-transfer function is transformed into a continuous-time transfer function, and parameters of the twomass system model are analytically solved from the coefficients of this transfer function. An open-loop identification setup and two closed-speed-loop identification setups (direct and indirect) are designed and experimentally compared. The experiments are carried out at nonzero speed to reduce the effect of nonlinear friction phenomena on the parameter estimates. According to results, all three identification setups are applicable for the parameter estimation of two-mass mechanical systems.

Analysis of Oscillation Frequency Deviation in Elastic Coupling Digital Drive System and Robust Notch Filter Strategy

“…A predetermined error boundary is set to get the rejection bandwidth Ω, and the on-line FFT result of speed feedback error signal is used to find the notch frequency ω n in this method [6]. After parameter determination, according to (24) and (30), the open loop transfer function of the system with notch filter G * (z) can be given as 0278-0046 (c) 2018 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission.…”

“…At first, off-line two-mass mechanical systems identification [29], [30] is used to determine the standard value f NTF of the systems that are coupled by elastic coupling 1 (f NTF =159Hz) and elastic coupling 2 (f NTF =203Hz). Considering the results of these two kinds of couplings are similar, only the data of coupling 1 is given out.…”

DSP implementation of state observers for electrical drive with elastic coupling

“…Mathematical model of the system is composed of three elements: model of the mechanical part, model of closed torque control loop and speed controller. In most articles two-mass mechanical system is considered [7]- [10]. Two-mass system with elasticity is physical model of the mechanical part of drive.…”

Identification of Dynamic Systems with Position Dependent Load Parameters

“…Offline methods to identify the frequency response are well-known. In [6], [7] and [8] torque excitation with a PRBS-signal is proven to be a successful technique for linear systems. In commercial drive manuals (e.g.…”