, • Combined feedforward plus feedback control can significantly improve
performance over simple feedback control whenever there is a major
disturbance that can be measured before it affects the process output.
• feedforward control can entirely eliminate the effect of the measured
disturbance on the process output.
• when there are modeling errors, feedforward control can often reduce the
effect of the measured disturbance on the output better than that
achievable by feedback control alone.
• the decision as to whether or not to use feedforward control depends on
whether the degree of improvement in the response to the measured
disturbance justifies the added costs of implementation and maintenance
• Feedforward control is always used along with feedback control because a
feedback control system is required to track setpoint changes and to
suppress unmeasured disturbances that are always present in any real
process.
performance over simple feedback control whenever there is a major
disturbance that can be measured before it affects the process output.
• feedforward control can entirely eliminate the effect of the measured
disturbance on the process output.
• when there are modeling errors, feedforward control can often reduce the
effect of the measured disturbance on the output better than that
achievable by feedback control alone.
• the decision as to whether or not to use feedforward control depends on
whether the degree of improvement in the response to the measured
disturbance justifies the added costs of implementation and maintenance
• Feedforward control is always used along with feedback control because a
feedback control system is required to track setpoint changes and to
suppress unmeasured disturbances that are always present in any real
process.
