Methods and systems for surge control

Patent metadata

Field	Value
Publication number	US-9816447-B2
Application number	US-201514592759-A
Country	US
Kind code	B2
Filing date	Jan 8, 2015
Priority date	Jan 8, 2015
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

Methods and systems are provided for calibrating a compressor surge line. In one example, a method may include adjusting the compressor surge line based on a vehicle speed in addition to a compressor pressure ratio. For example, at higher vehicle speeds, above a threshold vehicle speed, a less aggressive surge line calibration may be utilized in order to improve drivability while at lower vehicle speeds, below the threshold vehicle speed, a more aggressive surge line calibration may be utilized for NVH mitigation.

First claim

The invention claimed is:

1. A method for a boosted engine of a vehicle, comprising:
with a controller, during operation of the vehicle, determining a vehicle speed and adapting a surge line of a compressor map as a function of the vehicle speed.

2. The method of claim 1 , further comprising, with the controller, determining an engine speed of the vehicle and a compressor pressure ratio of the vehicle and further adapting the surge line as a function of the engine speed and the compressor pressure ratio.

3. The method of claim 2 , wherein the adapting includes, with the controller, using a first look-up table and a second look-up table in succession, inputting two of the engine speed, compressor pressure ratio, and vehicle speed into the first table and inputting an output of the first table and a remaining one of the engine speed, compressor pressure ratio, and vehicle speed into the second table, and using an output of the second table to adapt the surge line.

4. The method of claim 2 , wherein the adapting includes, with the controller, determining a first more aggressive surge-line calibration as a function of the compressor pressure ratio, determining a second less aggressive surge-line calibration as a function of the compressor pressure ratio; and blending the first and the second surge-line calibrations as a weighted function of the vehicle speed and/or the engine speed.

5. The method of claim 2 , wherein the adapting includes, with the controller, determining a final surge line based on a sum of a first output of a first look-up table and a second output of a second lookup table; and wherein the first table is obtained as a function of the engine speed and the compressor pressure ratio, and the second table is obtained as a function of the vehicle speed and the compressor pressure ratio.

6. The method of claim 1 , wherein the adapting includes, when the vehicle speed is below a threshold vehicle speed, adapting the surge line with a more aggressive calibration, and when the vehicle speed is above the threshold vehicle speed, adapting the surge line with a less aggressive calibration.

7. The method of claim 1 , wherein the controller learns the surge line adaptation over one or more vehicle drive cycles.

8. The method of claim 1 , wherein adapting the surge line includes, with the controller, adapting boundaries for each of a hard surge region and a soft surge region of the compressor map, wherein the compressor map further comprises constant compressor speed lines which have a positive slope in the soft surge region.

9. The method of claim 1 , further comprising, with the controller, adjusting an opening of a continuously variable compressor recirculation valve during the vehicle operation to maintain compressor operation at a higher compressor flow rate than a compressor flow rate of the adapted surge line.

10. The method of claim 9 , wherein the adjusting includes, with the controller, estimating a desired throttle mass flow based on engine operating conditions; estimating a threshold compressor flow rate based on the adapted surge line; and adjusting an opening of the continuously variable compressor recirculation valve based on a difference between the desired throttle mass flow and the threshold flow rate.

11. The method of claim 1 , wherein adapting the surge line as a function of the vehicle speed includes, with the controller, adapting the surge line with a more aggressive calibration during a tip-in occurring at a lower vehicle speed below a threshold vehicle speed to a higher vehicle speed above the threshold vehicle speed and adapting the surge line with a less aggressive calibration during a tip-out from the higher vehicle speed to the lower vehicle speed.

12. A method for a boosted engine, comprising:
in response to a tip-in at a higher vehicle speed above a threshold vehicle speed, adjusting a position of a continuously variable compressor recirculation valve to operate a compressor at a first higher compressor flow rate than a first surge line; and
in response to a tip-in at a lower vehicle speed below the threshold vehicle speed, adjusting the position of the continuously variable compressor recirculation valve to operate the engine compressor at a second higher compressor flow rate than a second surge line;
wherein, at a given compressor pressure ratio, a first compressor operating point on the second surge line has a higher compressor flow rate relative to a second compressor operating point on the first surge line.

13. The method of claim 12 , wherein at any given compressor pressure ratio on a compressor map, a compressor flow rate on the second surge line corresponding to the given compressor pressure ratio is greater than a compressor flow rate on the first surge line corresponding to the given compressor pressure ratio.

14. The method of claim 13 , further comprising, in response to a tip-out at the higher vehicle speed, adjusting the position of the continuously variable compressor recirculation valve to operate a compressor at a third higher compressor flow rate than the first surge line, and in response to a tip-out at the lower vehicle speed, adjusting the position of the continuously variable compressor recirculation valve to operate the compressor at a fourth higher compressor flow rate than the second surge line.

15. The method of claim 12 , wherein, in response to the tip-in at the higher vehicle speed, a continuously variable compressor recirculation valve opening is increased by a first, smaller amount; and wherein, in response to the tip-in at the lower vehicle speed, the continuously variable compressor recirculation valve opening is increased by a second, larger amount.

16. A vehicle system, comprising:
an engine;
a compressor for providing a boosted aircharge to the engine;
a compressor recirculation valve positioned in a passage coupling an outlet of the compressor to an inlet of the compressor, wherein a position of the valve is continuously variable between a fully open and a fully closed position; and
a controller with computer readable instructions stored in non-transitory memory for:
during vehicle operation, continually adjusting a default compressor map surge line with a calibration factor based on engine speed and vehicle speed; and
adjusting an opening of the compressor recirculation valve based on intake airflow to maintain compressor operation at a higher compressor flow rate than a surge limit of the adjusted surge line.

17. The system of claim 16 , wherein the default compressor map surge line is a vehicle manufacturer provided compressor map surge line determined based on component bench tests.

18. The system of claim 16 , wherein the adjusting the surge line includes calibrating the surge line less aggressively at a higher vehicle speed greater than a threshold vehicle speed, and calibrating the surge line more aggressively at a lower vehicle speed less than the threshold vehicle speed.

19. The system of claim 18 , wherein the controller includes further instructions for calibrating the surge line less aggressively at an engine speed greater than a first threshold engine speed, calibrating the surge line less aggressively at an engine speed less than a second threshold engine speed, and calibrating the surge line more aggressively at an engine speed less than the first threshold and greater than the second threshold.

20. The system of claim 16 , wherein a degree of aggressiveness of the calibration factor increases with a decrease in a vehicle speed below a thr

Assignees

• Ford Global Tech Llc

Inventors

• Jankovic Mrdjan J
• Buckland Julia Helen
• Ossareh Hamid-Reza
• Teng Charlie

Classifications

• F02D2200/501

  Vehicle speed · CPC title

• F02D2200/101

  Engine speed · CPC title

• F02D41/0007 Primary

  for control of turbo-charged or super-charged engines (control of the pumps per se F02B37/12) · CPC title

• F02D2700/07

  Automatic control systems according to one of the preceding groups in combination with control of the mechanism receiving the engine power · CPC title

• F02D41/2464

  Characteristics of actuators · CPC title