Patent Document ID: 5394322
Application ID: 08096600
Patent Flag: 1

Claim One:
1. Process control apparatus for attaining a selected closed-loop response of a control system, said apparatus comprising an outer-control loop having monitoring means, coupled to a controlled variable signal representative of a first characteristic of a process having an open-loop response, and to an operation control signal representative of a preselected value for said first characteristic of said process, said monitoring means for generating a difference signal representative of the difference between a signal characteristic of said controlled variable signal and said operation control signal, and an outer-control element coupled to said monitoring means and having means for storing at least one control parameter being representative of a control parameter of said process control apparatus, and having means for generating an outer control signal as a function of said control parameter and of said difference signal, for manipulating said first characteristic of said process toward said preselected value, an inner-control loop having an inner-control element coupled to said controlled variable signal and having means for storing one or more control parameters representative of control parameters of said process control apparatus and having means for generating an inner control signal as a function of a said control parameter and of said controlled variable signal, for manipulating said first characteristic of said process toward said preselected value, and summation means, coupled to said outer-control element and to said inner control element, for summing said inner-control signal and said outer-control signal to generate a manipulated variable signal for manipulating said first characteristic of said process toward said preselected value, and automatic tuning means for modifying said control parameters, said tuning means having means for storing at least one preselected closed-loop transfer function of said outer-control loop, and having means for storing at least one preselected closed-loop transfer function for said inner-control loop, and having means for storing at least one process model representative of a said open-loop process response, and having means for generating said control parameters as a function of said process model, and said preselected transfer functions, for tuning said inner-control loop and said outer-control to achieve substantially said selected closed-loop response.