Method for optimizing the pressure setting accuracy
In a method for optimizing the pressure setting accuracy, a hydraulic pressure is built up according to a pressure requirement of a hydraulic pump, and overflow control is performed using an analog-controlling hydraulic valve and a known control characteristic curve of the analog-controlling hydraulic valve, which overflow control counteracts a pressure build-up produced by the hydraulic pump that exceeds the pressure requirement. In addition to the known control characteristic curve of the analog-controlling hydraulic valve, at least one additional valve characteristic is taken into account for the overflow control.
1. A method for optimizing a pressure setting accuracy, wherein a hydraulic pressure is built up by a hydraulic pump in accordance with a pressure demand and wherein, using an analog-regulation hydraulic valve and a known actuation characteristic curve of the analog-regulation hydraulic valve, overflow regulation is performed which counteracts a pressure build-up, generated by the hydraulic pump, which goes beyond the pressure demand wherein in addition to the known actuation characteristic curve of the analog-regulation hydraulic valve, at least an overflow characteristic map is taken into consideration for the overflow regulation.
2. The method as claimed in claim 1 , wherein the overflow characteristic map represents an overflow behavior of a hydraulic valve of averaged characteristics.
3. The method as claimed in claim 1 , wherein the overflow characteristic map is modified on a valve-specific basis by the known actuation characteristic curve.
4. A method for optimizing a pressure setting accuracy, wherein a hydraulic pressure is built up by a hydraulic pump in accordance with a pressure demand and wherein, using an analog-regulation hydraulic valve and a known actuation characteristic curve of the analog-regulation hydraulic valve, overflow regulation is performed which counteracts a pressure build-up, generated by the hydraulic pump, which goes beyond the pressure demand wherein in addition to the known actuation characteristic curve of the analog-regulation hydraulic valve, at least one further valve characteristic is taken into consideration for the overflow regulation, wherein the known actuation characteristic curve is a valve-specific actuation characteristic curve.
5. The method as claimed in claim 1 , wherein the known actuation characteristic curve is determined after the connection of the hydraulic valve into a hydraulic or electrohydraulic vehicle brake system.
6. The method as claimed in claim 1 , wherein the analog-regulation hydraulic valve which is used to perform the overflow regulation is a cut-off valve of a hydraulic or electrohydraulic brake system.
7. A method for optimizing a pressure setting accuracy, wherein a hydraulic pressure is built up by a hydraulic pump in accordance with a pressure demand and wherein, using an analog-regulation hydraulic valve and a known actuation characteristic curve of the analog-regulation hydraulic valve, overflow regulation is performed which counteracts a pressure build-up, generated by the hydraulic pump, which goes beyond the pressure demand wherein in addition to the known actuation characteristic curve of the analog-regulation hydraulic valve, at least one further valve characteristic is taken into consideration for the overflow regulation, wherein an overflow characteristic map represents a regulation current versus a hydraulic fluid volume flow rate as a function of a pressure difference prevailing across the hydraulic valve.
8. The method as claimed in claim 7 , wherein a quantitative modification of the overflow characteristic map increases with the value of the deviation of an opening current determined on a valve-specific basis in the case of a pressure difference of substantially 0 bar from the opening current of a hydraulic valve of averaged characteristics, or increases with the value of the deviation of the closing current determined on a valve-specific basis in the case of a pressure difference of substantially 0 bar from the closing current of a hydraulic valve of averaged characteristics.
9. The method as claimed in claim 8 , wherein, if a closing current determined on a valve-specific basis in the case of a pressure difference of substantially 0 bar prevailing across the hydraulic valve is less than a closing current determined in the case of a pressure difference of substantially 0 bar prevailing across a hydraulic valve of averaged characteristics, a modification is performed for a reduction of the regulating current versus the hydraulic fluid volume flow rate in the overflow characteristic map.
10. The method as claimed in claim 8 , wherein, if a closing current determined on a valve-specific basis in the case of a pressure difference of substantially 0 bar prevailing across the hydraulic valve is greater than a closing current determined in the case of a pressure difference of substantially 0 bar prevailing across a hydraulic valve of averaged characteristics, a modification is performed for an increase of the regulation current versus the hydraulic fluid volume flow rate in the overflow characteristic map.
11. A method for optimizing a pressure setting accuracy, wherein a hydraulic pressure is built up by a hydraulic pump in accordance with a pressure demand and wherein, using an analog-regulation hydraulic valve and a known actuation characteristic curve of the analog-regulation hydraulic valve, overflow regulation is performed which counteracts a pressure build-up, generated by the hydraulic pump, which goes beyond the pressure demand wherein in addition to the known actuation characteristic curve of the analog-regulation hydraulic valve, at least one further valve characteristic is taken into consideration for the overflow regulation, wherein the known actuation characteristic curve is determined by a valve plunger position detection method.
12. A hydraulic or electrohydraulic vehicle brake system comprising:
at least one master cylinder for the supply of hydraulic fluid, at least one inlet valve for the admission of a pressure into at least one wheel brake cylinder assigned to a vehicle brake and at least one outlet valve for the release of the pressure from the at least one wheel brake cylinder assigned to a vehicle brake,
at least one hydraulic pump, at least one electronic control and regulation unit and at least one analog-regulation cut-off valve,
wherein the hydraulic pump builds up a hydraulic pressure in accordance with a pressure demand from the electronic control and regulation unit,
and the electronic control and regulation unit, using the cut-off valve and a stored actuation characteristic curve of the cut-off valve, performs overflow regulation which counteracts a pressure build-up, generated by the hydraulic pump, which goes beyond the pressure demand,
wherein, for the overflow regulation, the electronic control and regulation unit takes into consideration not only the stored actuation characteristic curve of the cut-off valve but also an overflow characteristic map of the cut-off valve.
13. The vehicle brake system as claimed in claim 12 , wherein, for the overflow regulation, the electronic control and regulation unit takes into consideration a stored overflow characteristic map as a further valve characteristic of the cut-off valve.
14. The vehicle brake system as claimed in claim 12 , wherein the electronic control and regulation unit modifies the stored overflow characteristic map on a valve-specific basis as a function of the stored actuation characteristic curve.
15. The vehicle brake system as claimed in claim 12 , wherein the electronic control and regulation unit determines and/or corrects the stored actuation characteristic curve of the cut-off valve repeatedly during operation.
16. Use of the method as claimed in claim 1 for pressure regulation in a system for inter-vehicle distance regulation and speed regulation of a motor vehicle.