Predictive position feedback controller for web guide control system

Claim 2

In an apparatus for process control including an electric signal responsive bidirectional single speed actuating device for controlling the position of a manipulated variable, means for sensing the process at a control point and for producing a process signal, and an electronic controller receiving said signal and controlling a timed voltage for driving the actuating device, the improvement being in the controller which comprises amplifying means receiving an error signal produced by comparing the process signal and a set point signal and amplifying same to produce an amplified output signal, a hysteretic switching device between the amplifying means and the actuating device triggered by the amplified output signal and controlling a voltage for the actuating device, and an integrator producing a feedback signal opposite to said output signal and having its input connected to the input voltage to the actuating device and its output summed with said output signal to produce a summed signal to time the summed signal to be on in proportion to the output signal wherein the position of the actuating device will be proportional to the output signal.

Claim 3

The controller of claim 1, wherein the integrator includes an operational amplifier having an input connected to the actuating device voltage and an output connected to a summing junction with the amplified output signal, a timing capacitor connected across said output and said input of the operational amplifier, and a timing resistor connected between said input and the actuating device voltage, wherein adjustment of the resistor adjusts the timing of the integrator.

Claim 4

The controller of claim 2, wherein the resistor is variable to adjust the timing of the integrator.

Claim 5

The controller of claim 1, and means for providing reset action in response to constant process error.

Claim 6

The controller of claim 4, wherein said reset action means includes an integral mode combined with said proportional amplifier.

Claim 7

The controller of claim 2, and means for providing reset action in response to constant process error.

Claim 8

The controller of claim 6, wherein said reset action means includes a resistor connected in the integrator in parallel with the timing capacitor which discharges to provide the reset action.

Claim 9

The controller of claim 6, wherein said reset action means includes a reset circuit consisting of a resistor connected in the integrator in series with an inverter between the amplified output signal and the input of the operational amplifier, and switch means responsive to the actuating device voltage to turn the circuit off when the actuating device voltage is on and to turn the circuit on when the actuating device voltage is off.

Claim 10

The controller of claim 6, wherein said reset action means includes a reset circuit consisting of a series combination of a resistor and a solid state switch connected in the integrator in parallel with the timing capacitor, said switch responsive to the actuating device voltage to turn the circuit off when the actuating device voltage is on and to turn the circuit on when the actuating device voltage is off.

Claim 11

In an apparatus for controlling a process variable including an electric signal responsive bi-directional single speed actuating device for controlling a manipulated variable, means for sensing the process at a control point and for producing a process signal, and an electronic controller receiving said signal and controlling a timed voltage for driving the actuating device, the improvement being in the controller which comprises a proportional plus integral mode receiving an error signal produced by comparing the process signal and a set point signal and amplifying same to produce an amplified output signal and producing reset action, a hysteretic switching device between the proportional plus integral mode and the actuating device triggered by the amplified output signal and controlling a voltage for the actuating, device, and an integrator producing a feedback signal opposite to said output signal and having its input connected to the input voltage to the actuating device and its output summed with said output signal to produce a summed signal to time the summed signal to be on in proportion to the output signal wherein the position of the actuating device will be proportional to the output signal.

Claim 12

In an apparatus for controlling a process variable including an electric signal responsive bi-directional single speed actuating device for controlling a manipulated variable, means for sensing the process at a control point and for producing a process signal, and an electronic controller receiving said signal and controlling a timed voltage for driving the actuating device, the improvement being in the controller which comprises a proportional plus integral mode receiving an error signal produced by comparing the process signal and a set point signal and amplifying same to produce an amplified output signal and producing reset action, a hysteretic switching device between the proportional plus integral mode and the actuating device triggered by the amplified output signal and controlling a voltage for the actuating, device, and an integrator producing a feedback signal opposite to said output signal and having its input connected to the input voltage to the actuating device and its output summed with said output signal to produce a summed signal to time the summed signal to be on in proportion to the output signal wherein the position of the actuating device will be proportional to the output signal.

Claim 13

The controller of claim 10, wherein the integrator includes an operational ampliFier having an input connected to the actuating device voltage and an output connected to a summing junction with the amplified output signal, a timing capacitor connected across the output and the input of the operational amplifier, and a timing resistor connected between the operational amplifier input and the actuating device voltage, wherein adjustment of the resistor adjusts the timing of the integrator.

Claim 14

The controller of claim 11, wherein the resistor is variable to adjust the timing of the integrator.

Claim 15

In an apparatus for process control including an electric signal responsive bi-directional single speed actuating device for controlling the position of a manipulated variable, means for sensing the process at a control point and for producing a process signal, means for producing a set point signal, and an electronic controller receiving and comparing the process and set point signals to produce an error signal which controls a timed voltage for driving the actuating device, the improvement being in the controller which comprises a hysteretic switching device receiving and triggered by the error signal and controlling a driving voltage for the actuating device, and an integrator producing a feedback signal opposite to said error signal having its input connected to the driving voltage of the actuating device and its output summed with the error signal to produce a summed signal to maintain said driving voltage on in proportion to said error signal, wherein the position of the actuating device will be proportional to said error signal.

Claim 16

In an apparatus for process control including an electric signal responsive bi-directional single speed actuating device for controlling the position of a manipulated variable, means for sensing the process at a control point and for producing a process signal, means for producing a set point signal, and an electronic controller receiving and comparing the process and set point signals to produce an error signal which controls a timed voltage for driving the actuating device, the improvement being in the controller which comprises a hysteretic switching device receiving and triggered by the error signal and controlling a driving voltage for the actuating device, and an integrator producing a feedback signal opposite to said error signal having its input connected to the driving voltage of the actuating device and its output summed with the error signal to produce a summed signal to maintain said driving voltage on in proportion to said error signal, wherein the position of the actuating device will be proportional to said error signal.