Identification of countercurrent rare earth extraction process based on local linear weighted state-space models

The identification problem of rare earth extraction process, which is based on local linear weighted state-space models, is considered in this paper. The parameter is determined by the optimization of output error cost function. In addition, the nonuniqueness of the fully parameterized state-space is considered and the parameter update is restricted to the direction that change the input-output behavior of the system by orthogonal gradient search. Finally, real industrial experiment of rare earth extraction is implemented and the results show the efficiency of the proposed method.