Parameter estimation for linear control valve with hysteresis
  The problem of estimating parameters of linear control valve with hysteresis is considered. The hysteretic behavior of control valve is formulated as a switched linear model. An indicator vector, which shows the switching epochs of switched linear model, is explored by subspace decomposition on measurements. With the help of indicator vector, the noisy measurements are classified into separate groups, each corresponding to up-stroke and down-stroke of control valve respectively. The least squares technique is adopted to estimate the parameters of control valve. It is shown that the proposed technique exactly estimates the parameters and switching epochs in absence of noise and exhibits dominant advantage in noisy case. 
Li Liang, Liu Jiannan, Wan Huaqing
cs.SY