Controller

Patent metadata

Field	Value
Publication number	US-11274624-B2
Application number	US-202017113255-A
Country	US
Kind code	B2
Filing date	Dec 7, 2020
Priority date	Dec 9, 2019
Publication date	Mar 15, 2022
Grant date	Mar 15, 2022

Abstract

A vehicle includes a pump configured to discharge a fuel by reciprocating a plunger, a rail configured to store the fuel discharged from the pump, and a fuel injection valve configured to inject the fuel supplied from the rail. A controller for the vehicle includes a waveform obtaining unit and a phase shift obtaining unit. The waveform obtaining unit is configured to obtain a waveform of a fuel pressure in the rail as a function of time in a predetermined period. The phase shift obtaining unit is configured to obtain a phase shift based on the waveform obtained by the waveform obtaining unit. The phase shift is an offset between a timing the plunger reciprocated in the pump arrives at a first position and a timing a piston reciprocating in an internal combustion engine arrives at a second position.

First claim

What is claimed is:

1. A controller for a vehicle, the vehicle including:
a pump configured to discharge a fuel by reciprocating a plunger;
a rail configured to store the fuel discharged from the pump; and
a fuel injection valve configured to inject the fuel supplied from the rail,
the controller comprising:
a waveform obtaining unit configured to obtain a waveform of a pressure of the fuel stored in the rail as a function of time in a predetermined period;
a phase shift obtaining unit configured to obtain a phase shift based on the waveform obtained by the waveform obtaining unit, the phase shift being an offset between a timing the plunger reciprocated in the pump arrives at a first position and a timing a piston reciprocating in an internal combustion engine of the vehicle arrives at a second position; and
a memory unit configured to store a correspondence table listing a plurality of reference waveforms and a plurality of reference phase shifts, wherein
the phase shift obtaining unit is further configured to obtain the phase shift by comprising the waveform obtained by the waveform obtaining unit with the plurality of reference waveforms stored in the memory unit and referring to the correspondence table in the memory unit.

2. The controller according to claim 1 , wherein
the plurality of reference waveforms stored in the memory unit are normalized such that a difference between a maximum value and a minimum value of the pressure in each of the plurality of reference waveforms has a predetermined value.

3. The controller according to claim 1 , wherein
the phase shift obtaining unit is further configured to:
normalize the waveform obtained by the waveform obtaining unit such that a difference between a maximum value and a minimum value of the pressure in the waveform has a predetermined value; and
obtain the phase shift by referring to the correspondence table using the normalized waveform.

4. The controller according to claim 1 further comprising
a matching rate calculating unit configured to calculate a matching rate between the waveform obtained by the waveform obtaining unit and each of the plurality of reference waveforms stored in the memory unit, wherein
the phase shift obtaining unit is further configured to obtain the phase shift by referring to the correspondence table using at least one of the plurality of reference waveforms that is selected based on the matching rate calculated by the matching rate calculating unit.

5. The controller according to claim 4 , wherein
the phase shift obtaining unit is further configured to obtain the phase shift by referring to the correspondence table using one of the plurality of reference waveforms that has a highest matching rate calculated by the matching rate calculating unit.

6. The controller according to claim 4 , wherein
the phase shift obtaining unit is further configured to obtain the phase shift by:
selecting two or more reference waveforms from the plurality of reference waveforms in the correspondence table, each of the two or more reference waveforms having the matching rate equal to or greater than a predetermined threshold;
selecting two or more reference phase shifts from the plurality of reference phase shifts in the memory unit corresponding to the two or more reference waveforms; and
averaging the selected two or more reference phase shifts.

7. The controller according to claim 4 , wherein
the waveform obtaining unit is further configured to sample a plurality of pressure values of the waveform at predetermined timings in the predetermined period, and
the matching rate calculating unit is further configured to calculate the matching rate by calculating a sum of squared differences between the plurality of pressure values and a plurality of corresponding reference pressure values of each of the plurality of reference waveforms in the correspondence table.

8. The controller according to claim 1 , wherein
the waveform obtaining unit is further configured to obtain the waveform when a predetermined obtaining condition is satisfied.

9. The controller according to claim 1 further comprising
an injection quantity correcting unit configured to correct an injection quantity of the fuel to be injected by the fuel injection valve based on the phase shift obtained by the phase shift obtaining unit.

10. The controller according to claim 9 , wherein
the injection quantity correcting unit is further configured to:
calculate a reference discharge quantity that is a quantity of the fuel theoretically discharged from the pump to the rail during a period the fuel is injected by the fuel injection valve at a specified phase shift;
calculate an actual discharge quantity that is a quantity of the fuel actually discharged from the pump to the rail during the period the fuel is injected by the fuel injection valve at the phase shift obtained by the phase shift obtaining unit;
calculate a difference between the reference discharge quantity and the actual discharge quantity; and
correct the injection quantity of the fuel to be injected by the fuel injection valve depending on the difference.

11. The controller according to claim 10 , wherein
the pump includes an adjusting valve configured to adjust a quantity of the fuel to be discharged from the pump to the rail depending on a requested quantity,
the memory unit stores a first reference graph of an estimated quantity of the fuel discharged from the pump to the rail as a function of time if the adjusting valve is fully opened, and
the injection quantity correcting unit is further configured to:
obtain a second reference graph by offsetting the first reference graph depending on the requested quantity;
calculate the reference discharge quantity by referring to the second reference graph;
obtain an actual discharge quantity graph by offsetting the first reference graph depending on the requested quantity and the phase shift obtained by the phase shift obtaining unit; and
calculate the actual discharge quantity by referring to the actual discharge quantity graph.

12. A controller for a vehicle, the vehicle including:
a pump configured to discharge a fuel by reciprocating a plunger;
a rail configured to store the fuel discharged from the pump; and
a fuel injection valve configured to inject the fuel supplied from the rail,
the controller comprising:
a processor programmed to:
obtain a waveform of a pressure of the fuel stored in the rail as a function of time in a predetermined period; and
obtain a phase shift based on the waveform, the phase shift being an offset between a timing the plunger reciprocated in the pump arrives at a first position and a timing a piston reciprocating in an internal combustion engine of the vehicle arrives at a second position; and

a memory configured to store a correspondence table listing a plurality of reference waveforms and a plurality of reference phase shifts, wherein
the processor is further programmed to obtain the phase shift by comparing the waveform obtained by the waveform obtaining unit with the plurality of reference waveforms stored in the memory unit and referring to the correspondence table in the memory unit.

13. The controller according to claim 12 , wherein
the plurality of reference waveforms stored in the memory unit are normalized such that a difference between a maximum value and a minimum value of the pressure in each of the plurality of reference waveforms has a predetermined value, and
the processor is further programed to:
normalize the waveform such that a difference between a maximum value and a minimum value of the pressure in the w

Assignees

• Denso Corp

Inventors

• Seki Naoto
• Yamada Naoyuki
• Syed Mohamed Mohamed Kuthbudeen

Classifications

• F02D41/38 Primary

  of the high pressure type · CPC title

• F02D41/3836 Primary

  Controlling the fuel pressure · CPC title

• F02M55/025

  Common rails · CPC title

• F02D1/00

  Controlling fuel-injection pumps, e.g. of high pressure injection type (F02D3/00 takes precedence) · CPC title

• F02D41/3863

  by controlling the flow out of the common rail, e.g. using pressure relief valves · CPC title