Method for controlling an electric pump drive motor of a power steering device

• US 20060151234A1
• Filed: 12/05/2005
• Published: 07/13/2006
• Est. Priority Date: 06/06/2003
• Status: Active Grant

• Current Assignee: TRW Automotive GmbH (Apollo Global Management, Inc.)
• Original Assignee: TRW Automotive GmbH (Apollo Global Management, Inc.)
• Inventors: Seidel, Mathias
• Granted Patent: US 7,505,840 B2
• Time in Patent Office: Days
• US Class Current: 180/442
• CPC Class Codes: B62D 5/065 characterised by specially adapted means for varying pressurised fluid supply based on need, e.g. on-demand, variable assist

Abstract

In a method for controlling an electric pump drive motor of a power steering device, a high output stage and a low output stage are provided, in which the motor can be operated. A switchover between the two output stages takes place as a function of the current consumption of the motor. Between the two output stages at least one further, middle output stage is provided, which can be switched into as a function of the current consumption of the motor.

Claims

1. A method for controlling an electric pump drive motor of a power steering device comprising the steps of:

(a) providing a motor having a high output stage, a low output stage and at least one further middle output stage, in which the motor can be operated, the motor being connected to a device for monitoring the motor current consuption;

(b) monitoring the current consumption of the motor; and

(c) switching over between the three output stages with the switching over taking place as a function of the current consumption of the motor.

2. The method according to claim 1, wherein the switchover of the motor between the individual output stages takes place as a function of at least one further switchover parameter.

3. The method according to claim 2, wherein one switchover parameter is the absolute current consumption according to the load of the pump driven by the motor.

4. The method according to claim 2, wherein one switchover parameter is the time-dependent change of the current consumption.

5. The method according to claim 2, wherein at least one of the output stages is changed as a function of at least one output parameter.

6. The method according to claim 5, wherein one output parameter is the vehicle velocity.

7. The method according to claim 6, wherein the output stage is changed such that with increasing vehicle velocity the speed of the motor decreases.

8. The method according to claim 5, wherein the change of the output stage takes place linearly to a change of the output parameter.

9. The method according to claim 6, wherein at least one of the following switchovers takes place by a gradual change of the speed of the motor and only after a delay time:

from the low output stage into the middle output stage;

from the high output stage into the middle output stage;

from the middle output stage into the low output stage.

10. The method according to claim 6, wherein at least one of the following switchovers takes place only after a delay time:

from the low output stage into the middle output stage;

from the high output stage into the middle output stage;

from the middle output stage into the low output stage.