MFA Overview
Model-Free Adaptive (MFA) control, as its name suggests,
is an adaptive control method that does not require
process models. This patented technology has been developed
by CyboSoft, General Cybernation Group Inc. (www.cybosoft.com).
A Model-Free Adaptive control system is defined to have
the following properties: (1) Precise quantitative knowledge
of the process is not necessary; (2) Process identification
mechanism or identifier is not included in the system;
(3) Controller design for a specific process is not
needed; (4) Manual tuning of controller parameters is
not required; and (5) Closed-loop system stability analysis
and criteria are available to guarantee the system stability.
Variations of the core MFA control technology address
specific control problems as described here.
• SISO
MFA to replace PID so that manual controller
tuning is eliminated,
• Nonlinear
MFA to control nonlinear processes,
• MFA
pH controller to control pH processes,
• Feedforward
MFA controller to deal with measurable
disturbances,
• Anti-delay
MFA to control processes with large time
delays,
• Robust
MFA to protect the process variable from
running outside a bound,
• Time-varying
MFA controller to control time varying
processes,
• Anti-delay
MFA pH controller for pH processes with
varying time delays, and
• MIMO
MFA to control multivariable processes.
General-purpose or application-specific MFA controllers
can be readily embedded and are becoming available on
more and more platforms offered by various vendors supplying
building controllers, single-loop controllers, programmable
logic controllers (PLCs), hybrid controllers, process
automation controllers (PAC), control software, and
distributed control systems (DCS).
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