US 2014/0005802 A1 · PROCESS CONTROL APPARATUS & METHOD

Abstract

A control device, a control method and system for controlling switching in/out of execution device in a system having plurality of execution devices in parallel, are disclosed. A group of execution devices perform predetermined operations on an execution object. The control device comprises feedback unit configured to provide the difference between reference quantity and feedback quantity; and at least one control unit corresponding to each execution device of the group of execution devices respectively, which is configured to provide a target value to a driver of a corresponding execution device using a control mode based on the difference, and when any of the other execution devices are switched in/out, provide a target value to the driver using another control mode. The driver drives the corresponding execution device based on the target value. The impact to the execution object may be suppressed and/or the adjustment time may be shortened.

Claims29

Dependent claims

A process control apparatus for controlling a process variable, comprising a plurality of process control devices arranged to control the process variable, the apparatus further comprising:

a demand device configured to provide a demand signal for the variable;
and
at least one controller operable to control a first group comprising at least one of the devices, the controller being arranged to:
provide a demand signal to the or each device of the first group using a first control mode based on the demand signal, and
provide a demand signal to the or each device of the first group using a second control mode which is different from the first control mode when another device is being switched in or out of operation in a transition, wherein the device or devices in the first group is/are controlled based on the demand signal, the second control mode controlling the devices of the first group during the switching in or out of the other device so that the control of the variable is less disturbed in the transition.

2 more elements

A method for controlling devices in which a plurality of process control devices in parallel control a process variable arranged as a first group comprising at least one device and at least another device not in the first group, the method comprising:

when the other device or devices are not being switched in or out of operation to control the variable, providing a demand signal to the at least one device of the first group using a first control mode,
when any one or more of the other devices are being switched in or out of operation to control the variable, providing a demand signal to the device using a second control mode which is different from the first control mode, and driving the device or devices of the first group based on the demand signal.

Dependencies are inferred from the claim text.

Process control apparatus & method

Life of this patent

Process control apparatus & method

Life of this patent

Abstract

Claims29