Method of adaptively sampling data to determine the start of injection in a solenoid actuated valve

Patent metadata

Field	Value
Publication number	US-11242941-B2
Application number	US-201816628097-A
Country	US
Kind code	B2
Filing date	Jul 4, 2018
Priority date	Jul 5, 2017
Publication date	Feb 8, 2022
Grant date	Feb 8, 2022

Abstract

A method of adaptively sampling data to determine the start of injection in a solenoid actuated valve of a fluid injector includes, in an operating cycle or portion thereof of the valve, sampling the signal of current through a solenoid of the valve at sampling points having a pre-defined interval therebetween. At each sampling point, determining the value of the first derivative of current and detecting the sampling point at which the first derivative achieves a maximum as the start of injection. Values of the first derivative of the sampling points immediately preceding and immediately following the start of injection are determined. In a subsequent operating cycle, synchronisation of sampling is altered to shift sampling times depending on the values of the first derivative of the sampling points immediately preceding and immediately following the start of injection.

First claim

The invention claimed is:

1. A method of adaptively sampling data to determine a start of injection in a solenoid actuated valve of a fluid injector comprising:
a) in an operating cycle or portion thereof of said solenoid actuated valve, sampling a signal of current through a solenoid of the solenoid actuated valve at sampling points, said sampling points having a pre-defined interval therebetween;
b) at each of said sampling points, determining a value of a first derivative of the current;
c) detecting a sampling point at which the value of the first derivative achieves a maximum and determining this sampling point as the start of injection;
d) determining the value of the first derivative at a sampling point immediately preceding said sampling point of step c);
e) determining the value of the first derivative at a sampling point immediately following said sampling point of step c);
f) in a subsequent operating cycle, altering a synchronisation of sampling to shift sampling times time wise depending on the values found in steps d) and e).

2. A method as claimed in claim 1 wherein in step f) if the value in step d) is greater than the value in step e), shifting sampling times earlier in time by a set increment.

3. A method as claimed in claim 2 wherein in step f) if the value in step d) is smaller than the value in step e), shifting sampling times forward in time by a set increment.

4. A method as claimed in claim 3 where said injector is a reductant injector adapted to inject liquid reductant into an exhaust of a vehicle.

5. A method as claimed in claim 1 wherein in step f) if the value in step d) is smaller than the value in step e), shifting sampling times forward in time by a set increment.

6. A method as claimed in claim 5 where said injector is a reductant injector adapted to inject liquid reductant into an exhaust of a vehicle.

7. A method as claimed in claim 1 where said injector is a reductant injector adapted to inject liquid reductant into an exhaust of a vehicle.

Assignees

• Delphi Tech Ip Ltd

Inventors

• Sykes Martin A
• Knowles Peter

Classifications

• F01N3/208 Primary

  Control of selective catalytic reduction [SCR], e.g. by adjusting the dosing of reducing agent · CPC title

• F01N3/0253

  adding fuel to exhaust gases · CPC title

• F02D2041/2058

  using information of the actual current value · CPC title

• Y02T10/40

  Engine management systems · CPC title

• F01N2900/0402

  using adaptive learning · CPC title