Delay-minimized detection of an auxiliary control variable

1. A method for the delay-minimized detection of an auxiliary control variable for a system comprising a control system and a controller, whereby an output variable is detected at the end of the control system, whereby a disturbance variable is active in the control system, wherein the system is a hydraulic system containing a hydraulic fluid and having a capacity (c), and the detected output variable is either the pressure (p) of the hydraulic fluid or is a mechanical variable, the latter being a force that is generated by a hydraulic cylinder to which a pressure (p) can be applied by means of a hydraulic fluid, comprising the steps of:

detecting a state variable in the control system at a place before a point of action of the disturbance variable;

whereby the auxiliary control variable is calculated from the state variable that has been weighted with a constant k x and from an estimation error (e) wherein the constant k x is inversely proportional to the capacity (c) of the hydraulic system; and

whereby the estimation error (e) is calculated from a comparison between the detected output variable and the integrated auxiliary control variable.

2. The method according to claim 1 , wherein the estimation error (e) is weighted with a proportional factor before it is added to the state variable that has been weighted with the constant k x .

3. The method according to claim 1 , wherein the system is a hydraulic system containing a hydraulic fluid, and the detected output variable is a mechanical variable, the latter being a force that is generated by a hydraulic cylinder to which a pressure (p) can be applied by means of a hydraulic fluid.

4. The method according to claim 2 , wherein the system is a hydraulic system containing a hydraulic fluid, and the detected output variable is a mechanical variable, the latter being a force that is generated by a hydraulic cylinder to which a pressure (p) can be applied by means of a hydraulic fluid.

5. The method according to claim 1 , wherein the system is a hydraulic system containing a hydraulic fluid, and the detected output variable is the pressure (p) of the hydraulic fluid.

6. The method according to claim 2 , wherein the system is a hydraulic system containing a hydraulic fluid, and the detected output variable is the pressure (p) of the hydraulic fluid.

7. The method according to claim 3 , wherein the hydraulic system comprises a component by means of which a volumetric flow (Q) of the hydraulic fluid can be generated that leads to a pressure change ({dot over (p)}) in the hydraulic system.

8. The method according to claim 5 , wherein the hydraulic system comprises a component by means of which a volumetric flow (Q) of the hydraulic fluid can be generated that leads to a pressure change ({dot over (p)}) in the hydraulic system.

9. The method according to claim 7 , wherein the component by means of which a volumetric flow (Q) can be generated is a valve, whereby the hydraulic system can be connected to a constant-pressure network via the valve and whereby the valve controls the volumetric flow (Q) between the constant-pressure network and the hydraulic system.

10. The method according to claim 7 , wherein the component by means of which a volumetric flow (Q) can be generated is a constant pump driven by a motor, whereby the volumetric flow (Q) is adjusted by varying the motor speed (n).

11. The method according to claim 7 , wherein the component by means of which a volumetric flow (Q) can be generated is a displacement pump driven by a motor, whereby the volumetric flow (Q) is adjusted by varying the delivery volume per rotation and/or by varying the motor speed (n).

12. The method according to claim 10 , wherein the constant k x is inversely proportional to the capacity (c) of the hydraulic system and proportional to the motor speed (n) and to the pump delivery rate.

13. The method according to claim 11 , wherein the constant k x is inversely proportional to the capacity (c) of the hydraulic system and proportional to the motor speed (n) and to the pump delivery rate.

14. The method according to claim 1 , wherein the auxiliary control variable is an estimated pressure change ({circumflex over ({dot over (p)})}) in the hydraulic system.

15. A hydraulic system comprising:

a control system;

a sensor system for detecting an output variable at the end of the control system; and

a controller for controlling the output variable;

wherein the control system can be acted upon by a disturbance variable at a point of action;

wherein the hydraulic system contains a hydraulic fluid and has a capacity (c), and the output variable at the end of the control system is either the pressure (p) of the hydraulic fluid or is a mechanical variable, the latter being a force that is generated by a hydraulic cylinder to which a pressure (p) can be applied by means of a hydraulic fluid,

wherein a state variable can be detected in the control loop at a place before the point of action of the disturbance variable;

wherein an auxiliary control variable can be calculated from the state variable that has been weighted with a constant k x and from an estimation error (e) wherein the constant k x is inversely proportional to the capacity (c) of the hydraulic system; and

wherein the estimation error (e) is calculated from a comparison between the detected output variable and the integrated auxiliary control variable.

16. The system according to claim 15 , wherein the detected output variable can be averaged by means of a filter for purposes of the detection.

17. The system according to claim 15 , wherein the system is a hydraulic system containing a hydraulic fluid, and the detected output variable is a mechanical variable, the latter being a force that is generated by a hydraulic cylinder to which a pressure (p) can be applied by means of a hydraulic fluid.

18. The system according to claim 16 , wherein the system is a hydraulic system containing a hydraulic fluid, and the detected output variable is a mechanical variable, the latter being a force that is generated by a hydraulic cylinder to which a pressure (p) can be applied by means of a hydraulic fluid.

19. The system according to claim 15 , wherein the system is a hydraulic system containing a hydraulic fluid, and the detectable output variable is the pressure (p) of the hydraulic fluid.

20. The system according to claim 16 , wherein the system is a hydraulic system containing a hydraulic fluid, and the detectable output variable is the pressure (p) of the hydraulic fluid.

21. The system according to claim 17 , wherein the hydraulic system comprises a component by means of which a volumetric flow (Q) of the hydraulic fluid can be generated that leads to a pressure change ({dot over (p)}) in the hydraulic system.

22. The system according to claim 21 , wherein the component by means of which a volumetric flow (Q) can be generated is a valve, whereby the hydraulic system can be connected to a constant-pressure network via the valve, and whereby the valve can control the volumetric flow (Q) between the constant-pressure network and the hydraulic system.

23. The system according to claim 21 , wherein the component by means of which a volumetric flow (Q) can be generated is a constant pump driven by a motor, whereby the volumetric flow (Q p ) is adjusted by varying the motor speed (n).

24. The system according to claim 21 , wherein the component by means of which a volumetric flow (Q) can be generated is a displacement pump driven by a motor, whereby the volumetric flow (Q p ) is adjusted by changing the delivery volume per rotation and/or by varying the motor speed (n).

25. The system according to claim 21 , wherein an electronic circuit is arranged on the component that generates the volumetric flow (Q), whereby said circuit can be used to carry out a method according to claim 1 .