Identification of continuous-time hybrid ‘Box-Jenkins’ systems having multiple unknown time delays

2018 ◽  
Vol 41 (2) ◽  
pp. 366-377
Author(s):  
Yamna Ghoul ◽  
Kaouther Ibn Taarit ◽  
Moufida Ksouri

For many years, various methods for the identification of parameters of continuous-time models have been available and implemented in widely. However, most methods apply models where the output are contaminated by a white noise or without noise in some others cases, which are unrealistic in most practical applications owing to their associated noise structure. Some other methods neglect the presence of time delays. Then it can be shown that the estimates are not statistically efficient. To cope with this issue, this paper deals with the identification of multi-input single-output continuous-time hybrid ‘Box-Jenkins’ systems having multiple unknown time delays from sampled input/output data. The proposed work presents a based-instrumental variable method for the separable estimation of both process parameters, multiple unknown time delays and the noise model. The effectiveness of the proposed scheme is proven through a numerical example illustrated by Monte Carlo analysis.

2019 ◽  
Vol 36 (6) ◽  
pp. 2111-2130
Author(s):  
Yamna Ghoul

Purpose This study/paper aims to present a separable identification algorithm for a multiple input single output (MISO) continuous time (CT) hybrid “Box–Jenkins”. Design/methodology/approach This paper proposes an optimal method for the identification of MISO CT hybrid “Box–Jenkins” systems with unknown time delays by using the two-stage recursive least-square (TS-RLS) identification algorithm. Findings The effectiveness of the proposed scheme is shown with application to a simulation example. Originality/value A two-stage recursive least-square identification method is developed for multiple input single output continuous time hybrid “Box–Jenkins” system with multiple unknown time delays from sampled data. The proposed technique allows the division of the global CT hybrid “Box–Jenkins” system into two fictitious subsystems: the first one contains the parameters of the system model, including the multiple unknown time delays, and the second contains the parameters of the noise model. Then the TS-RLS identification algorithm can be applied easily to estimate all the parameters of the studied system.


Author(s):  
Ste´phane Victor ◽  
Rachid Malti ◽  
Alain Oustaloup

This paper deals with continuous-time system identification using fractional differentiation models in a colored noisy output context. An optimal instrumental variable method for identifying hybrid fractional Box-Jenkins models is described. The relationship between the measured input and the output is a fractional continuous-time transfer function, and the noise is a discrete-time AR or ARMA process. The method is illustrated on a simulation example.


Sign in / Sign up

Export Citation Format

Share Document