Parameter estimation in an actuator

Patent metadata

Field	Value
Publication number	US-9777660-B2
Application number	US-201514658379-A
Country	US
Kind code	B2
Filing date	Mar 16, 2015
Priority date	Mar 20, 2014
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

A method for parameter estimation in an electromagnetic actuator having an electrical coil and an armature includes applying a voltage pulse to the electrical coil of the actuator prior to an actuator event and of sufficient duration to ensure that a resulting electrical current achieves steady state. At least one parameter of the actuator is estimated based upon the voltage pulse and the steady state current.

First claim

The invention claimed is:

1. A method for parameter estimation in an electromagnetic actuator comprising an electrical coil and an armature, the method comprising:
applying a voltage pulse to the electrical coil of the actuator prior to an actuator event, said voltage pulse of sufficient duration to ensure that a resulting electrical current achieves steady state and having an amplitude insufficient to cause armature displacement; and
estimating at least one parameter of the actuator based upon the voltage pulse and the steady state current.

2. The method of claim 1 , wherein said at least one parameter of the actuator comprises electrical coil resistance, and wherein estimating electrical coil resistance is in accordance with the following relationship:

R
=

V
EC

i

wherein V EC is the voltage pulse,
i is the steady state current, and
R is the electrical coil resistance.

3. The method of claim 2 , wherein said at least one parameter further comprises actuator temperature, and wherein estimating actuator temperature is in accordance with the following relationship:
R ( T )= R 0 [(1+α( T−T 0 )]

wherein R is electrical coil resistance,
T is actuator temperature,
R 0 is a predetermined resistance of the electrical coil at a predetermined temperature T 0 ,
T 0 is the predetermined temperature, and
α is a temperature coefficient of the electrical coil.

4. The method of claim 2 , wherein said at least one parameter further comprises electrical coil inductance, and wherein estimating electrical coil inductance comprises:
determining a time constant corresponding to said resulting electrical current achieving a predetermined percentage of steady state current; and
estimating the electrical coil inductance based upon the estimated resistance of the electrical coil and the determined time constant in accordance with the following relationship:
L=R×T C
wherein L is the inductance of the electrical coil,
R is the estimated resistance of the electrical coil, and
T c is the time constant.

5. The method of claim 1 , wherein applying the voltage pulse comprises pulse width modulating a voltage at a predetermined magnitude and duty cycle.

6. An electromagnetic actuator system, comprising:
an electrical coil;
an armature;
a control module configured to:
apply a voltage pulse to the electrical coil of the actuator prior to an actuator event, said voltage pulse of sufficient duration to ensure that a resulting electrical current achieves steady state and having an amplitude insufficient to cause armature displacement; and
estimate at least one parameter of the actuator based upon the voltage pulse and the steady state current.

7. The electromagnetic actuator system of claim 6 , wherein said at least one parameter of the actuator comprises electrical coil resistance, and wherein electrical coil resistance is estimated in accordance with the following relationship:

R
=

V
EC

i

wherein V EC is the voltage pulse,
i is the steady state current, and
R is the electrical coil resistance.

8. The electromagnetic actuator system of claim 7 , wherein said at least one parameter further comprises actuator temperature, and wherein actuator temperature is estimated in accordance with the following relationship:
R ( T )= R 0 [(1+α( T−T 0 )]

wherein R is electrical coil resistance,
T is actuator temperature,
R 0 is a predetermined resistance of the electrical coil at a predetermined temperature T 0 ,
T 0 is the predetermined temperature, and
α is a temperature coefficient of the electrical coil.

9. The electromagnetic actuator system of claim 7 , wherein said at least one parameter further comprises electrical coil inductance, and wherein estimating electrical coil inductance comprises:
determining a time constant corresponding to said resulting electrical current achieving a predetermined percentage of steady state current; and
estimating the electrical coil inductance based upon the estimated resistance of the electrical coil and the determined time constant in accordance with the following relationship:
L=R×T C
wherein L is the inductance of the electrical coil,
R is the estimated resistance of the electrical coil, and
T C is the time constant.

10. The electromagnetic actuator system of claim 6 , wherein applying the voltage pulse comprises pulse width modulating a voltage at a predetermined magnitude and duty cycle.

11. An electromagnetic fuel injection system, comprising:
a fuel injector comprising:
an electrical coil; and
an armature; and

a control module configured to:
apply a voltage pulse to the electrical coil of the fuel injector prior to an actuator event, said voltage pulse of sufficient duration to ensure that a resulting electrical current achieves steady state and having an amplitude insufficient to cause armature displacement; and
estimate at least one parameter of the fuel injector based upon the voltage pulse and the steady state current.

12. The electromagnetic fuel injection system of claim 11 , wherein said at least one parameter of the fuel injector comprises electrical coil resistance, and wherein electrical coil resistance is estimated in accordance with the following relationship:

R
=

V
EC

i

wherein VEC is the voltage pulse,
i is the steady state current, and
R is the electrical coil resistance.

13. The electromagnetic fuel injection system of claim 12 , wherein said at least one parameter further comprises fuel injector temperature, and wherein fuel injector temperature is estimated in accordance with the following relationship:
R ( T )=R 0 [(1+α( T−T 0 )]

wherein R is electrical coil resistance,
T is actuator temperature,
R 0 is a predetermined resistance of the electrical coil at a predetermined temperature T 0 ,
T 0 is the predetermined temperature, and
α is a temperature coefficient of the electrical coil.

14. The electromagnetic fuel injection system of claim 11 , wherein applying the voltage pulse comprises pulse width modulating a voltage at a predetermined magnitude and duty cycle.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Namuduri Chandra S
• Gopalakrishnan Suresh
• Nehl Thomas Wolfgang
• Omekanda Avoki M

Classifications

• G01R31/72

  Testing of electric windings (testing of transformers G01R31/62) · CPC title

• F02M51/005

  Arrangement of electrical wires and connections, e.g. wire harness, sockets, plugs; Arrangement of electronic control circuits in or on fuel injection apparatus · CPC title

• F02D41/20 Primary

  Output circuits, e.g. for controlling currents in command coils · CPC title

• F02M51/061

  using electromagnetic operating means · CPC title

• F02D2041/2065

  the control being related to the coil temperature · CPC title