Method and module for filtering a raw setpoint

1. A method of filtering a raw setpoint for a corrector network in a system for regulating an engine speed, said method comprising:

detecting a filtering condition for filtering the raw setpoint, wherein detecting the filtering condition comprises determining that the raw setpoint exceeds a protection threshold value;

filtering the raw setpoint to generate a filtered setpoint of the engine speed when the filtering condition is detected; and

supplying the filtered setpoint to the corrector network instead of the raw setpoint when the filtering condition is detected,

wherein filtering the raw setpoint to generate the filtered setpoint comprises:

setting the filtered setpoint to the protection threshold value when the filtering condition is detected;

maintaining the filtered setpoint at the protection threshold value until the engine speed has stabilized, for a stabilization duration, around the set filtered setpoint; and

increasing the filtered setpoint progressively up to the raw setpoint once the engine speed has stabilized for the stabilization duration around the set filtered setpoint.

2. The method of claim 1 , wherein the filtering condition is detected, the method further comprising determining whether the engine speed has stabilized around the filtered setpoint.

3. The method of claim 1 , wherein progressively increasing the filtered setpoint comprises progressively increasing the filtered setpoint according to a ramp.

4. The method of claim 1 , further comprising supplying the raw setpoint to the corrector network so long that the filtering condition is not detected.

5. A module for filtering a raw setpoint for a corrector network in a system for regulating an engine speed, said module comprising:

a first module configured to detect a filtering condition for filtering the raw setpoint, wherein the first module detects the filtering condition by determining that the raw setpoint exceeds a protection threshold value;

a gradient limiter configured to filter the raw setpoint to generate a filtered setpoint of the engine speed when the filtering condition is detected, wherein filtering the raw setpoint comprises:

setting the filtered setpoint to the protection threshold value when the filtering condition is detected;

maintaining the filtered setpoint at the protection threshold value until the engine speed has stabilized, for a stabilization duration, around the set filtered setpoint; and

increasing the filtered setpoint progressively up to the raw setpoint once the engine speed has stabilized for the stabilization duration around the set filtered setpoint;

and

a second module configured to supply the corrector network with the filtered setpoint instead of the raw setpoint when the filtering condition is detected.

6. The module of claim 5 , further comprising:

a third module configured, when the filtering condition is detected, to determine whether the engine speed has stabilized around the filtered setpoint.

7. The module of claim 5 , wherein the gradient limiter is configured to gradually increase the filtered setpoint according to a ramp.

8. The module of claim 5 , wherein the second module is configured to supply the raw setpoint to the corrector network so long that the filtering condition is not detected.

9. A system for regulating a turbojet, the system comprising a filtering module according to claim 5 , a corrector network, a jet, and a speed sensor.

10. A turbojet including a regulator system according to claim 9 .

11. A method of filtering a raw setpoint in a system for regulating an engine speed, comprising:

determining whether the raw setpoint exceeds a protection threshold value;

if the raw setpoint exceeds the protection threshold value,

filtering the raw setpoint to generate a filtered setpoint wherein said filtering comprises:

setting the filtered setpoint to the protection threshold value;

maintaining the filtered setpoint at the protection threshold value until the engine speed has stabilized, for a stabilization duration, around the set filtered setpoint; and

increasing the filtered setpoint progressively up to the raw setpoint once the engine speed has stabilized for the stabilization duration around the set filtered setpoint; and

supplying the filtered setpoint to a corrector network; and

if the raw setpoint does not exceed the protection threshold value, supplying the raw setpoint to the corrector network.

12. The method of claim 11 , wherein the raw setpoint exceeds the protection threshold value, the method further comprising determining whether the engine speed has stabilized around the filtered setpoint.

13. The method of claim 12 , further comprising gradually increasing the filtered setpoint up to the raw setpoint according to a ramp if the engine speed has stabilized around the filtered setpoint.