MOTOR CONTROLLER AND ELECTRIC POWER STEERING APPARATUS

• US 20080309270A1
• Filed: 06/13/2008
• Published: 12/18/2008
• Est. Priority Date: 06/14/2007
• Status: Active Grant

• Current Assignee: Jtekt Corporation (Toyota Motor Corporation)
• Original Assignee: Jtekt Corporation (Toyota Motor Corporation)
• Inventors: SUZUKI, Hiroshi
• Granted Patent: US 7,880,417 B2
• Time in Patent Office: Days
• US Class Current: 318/432
• CPC Class Codes: B62D 5/0484 for reaction to failures, e.g. limp home
• CPC Class Codes: B62D 5/0487 detecting motor faults B62D5/0496 takes precedence

Abstract

In a motor controller, in the case that occurrence of a failure of electric current flow is detected in any phase of a motor, a phase electric current command value changing in accordance with a secant curve or a cosecant curve with an asymptotic line at a predetermined rotation angle corresponding to the phase in which the failure of electric current flow has occurred is calculated. The calculated phase electric current command value is limited in such a manner as to become within a predetermined range. In the case that a rotation angle of the motor exists in a range in which the phase electric current command value is limited, the execution of an anomaly detection of a control system utilizing an electric current deviation of a d/q coordinate system is inhibited.

Claims

1. A motor controller comprising:

a motor control signal output section; and

a drive circuit feeding a three phase drive power to a motor on the basis of a motor control signal output from the motor control signal output section,

wherein the motor control signal output section includes;

an electric current command value calculating section;

a motor control signal generating section generating the motor control signal by executing an electric current feedback control of a d/q coordinate system on the basis of an electric current command value calculated by the electric current command value calculating section; and

an anomaly detecting section for detecting an anomaly of a control system on the basis of an electric current deviation of the d/q coordinate system, and detecting a failure of electric current flow in any of the phases of the motor,

wherein, in a case that a failure of electric current flow occurred in any of the phases of the motor is detected by the anomaly detecting section, the electric current command value calculating section calculates a phase electric current command value changing in accordance with a secant curve or a cosecant curve with an asymptotic line at a predetermined rotation angle corresponding to the phase in which the failure of electric current flow has occurred, and the motor control signal generating section generates a motor control signal for energizing the other two phases than the phase in which the failure of electric current flow has occurred by executing a phase electric current feedback control on the basis of the calculated phase electric current command value,

wherein the motor control signal output section is provided with a guarding section for limiting the phase electric current command value calculated by the electric current command value calculating section within a predetermined range, and

wherein, in the case of detecting that a failure of electric current flow has occurred in any of the phases of the motor, the anomaly detecting section inhibits the anomaly detection of the control system if the rotation angle of the motor exists in the range in which the phase electric current command value is limited by the guarding section.

2. An electric power steering apparatus having the motor controller according to claim 1.

3. A motor controller comprising:

a motor control signal output section; and

a drive circuit feeding a three phase drive power to a motor on the basis of a motor control signal output from the motor control signal output section,

wherein the motor control signal output section includes;

an electric current command value calculating section;

a motor control signal generating section generating the motor control signal by executing an electric current feedback control of a d/q coordinate system on the basis of an electric current command value calculated by the electric current command value calculating section; and

an anomaly detecting section for detecting an anomaly of a control system on the basis of a comparison between an electric current deviation of the d/q coordinate system and a predetermined threshold value, and detecting a failure of electric current flow in any of the phases of the motor,

wherein, in a case that a failure electric current flow occurred in any of the phases of the motor is detected by the anomaly detecting section, the electric current command value calculating section calculates a phase electric current command value changing in accordance with a secant curve or a cosecant curve with an asymptotic line at a predetermined rotation angle corresponding to the phase in which the failure of electric current flow has occurred, and the motor control signal generating section generates a motor control signal for energizing the other two phases than the phase in which the failure of electric current flow has occurred by executing a phase electric current feedback control on the basis of the calculated phase electric current command value,

wherein the motor control signal output section is provided with a guarding section for limiting the phase electric current command value calculated by the electric current command value calculating section within a predetermined range, and

wherein, in the case of detecting that a failure of electric current flow has occurred in any of the phases of the motor, the anomaly detecting section changes the threshold value so as to correspond to a fluctuation of the electric current deviation of the d/q coordinate system generated by the limitation of the phase electric current command value if the rotation angle of the motor exists in the range in which the phase electric current command value is limited by the guarding section.

4. The motor controller according to claim 3, wherein the electric current command value calculating section calculates the phase electric current command value on the basis of any one of the following expressions (1) to (3) in correspondence to the phase of the motor in which the failure of electric current flow has occurred:

in the case that the failure of electric current flow has occurred in the U phase;

5. An electric power steering apparatus having the motor controller according to claim 3.

6. A motor controller comprising:

a motor control signal output section; and

a drive circuit feeding a three phase drive power to a motor on the basis of a motor control signal output from the motor control signal output section,

wherein the motor control signal output section includes;

an electric current command value calculating section;

a motor control signal generating section generating the motor control signal by executing an electric current feedback control of a d/q coordinate system on the basis of an electric current command value calculated by the electric current command value calculating section; and

an anomaly detecting section for detecting an anomaly of a control system on the basis of an electric current deviation of the d/q coordinate system, and detecting a failure of electric current flow in any of the phases of the motor,

wherein, in a case that a failure of electric current flow occurred in any of the phases of the motor is detected by the anomaly detecting section, the electric current command value calculating section calculates a phase electric current command value changing in accordance with a secant curve or a cosecant curve with an asymptotic line at a predetermined rotation angle corresponding to the phase in which the failure of electric current flow has occurred, and the motor control signal generating section generates a motor control signal for energizing the other two phases than the phase in which the failure of electric current flow has occurred, by executing a phase electric current feedback control on the basis of the calculated phase electric current command value,

wherein the motor control signal output section is provided with a guarding section for limiting the phase electric current command value calculated by the electric current command value calculating section within a predetermined range, and

wherein, in the case of detecting that a failure of electric current flow has occurred in any of the phases of the motor, the anomaly detecting section calculates a hypothetical electric current command value of the d/q coordinate system, the hypothetic electric current command value corresponding to the phase electric current command value calculated by the electric current command value calculating section, and the anomaly detecting section executes the anomaly detection of the control system on the basis of a deviation between the calculated hypothetical electric current value and an actual electric current value of the d/q coordinate system.

7. The motor controller according to claim 6, wherein the electric current command value calculating section calculates the phase electric current command value on the basis of any one of the following expressions (17) to (19) in correspondence to the phase of the motor in which the failure of electric current flow has occurred:

in the case that the failure of electric current flow has occurred in the U phase;

8. A motor controller according to claim 6, wherein the electric current command value calculating section calculates the phase electric current command value on the basis of any of the following expressions (36) to (38) in correspondence to the phase of the motor in which the failure of electric current flow has occurred:

in the case that a failure of electric current flow has occurred in the U phase;

9. An electric power steering apparatus having the motor controller according to claim 6.

10. A motor controller comprising:

a motor control signal output section; and

a drive circuit feeding a three phase drive power to a motor on the basis of a motor control signal output from the motor control signal output section,

wherein the motor control signal output section includes;

an electric current command value calculating section;

a motor control signal generating section generating the motor control signal by executing an electric current feedback control of a d/q coordinate system on the basis of an electric current command value calculated by the electric current command value calculating section; and

an anomaly detecting section for detecting an anomaly of a control system and a failure of electric current flow in any of the phases of the motor,

wherein, in a case that a failure of electric current flow occurred in any of the phases of the motor is detected by the anomaly detecting section, the electric current command value calculating section calculates a phase electric current command value changing in accordance with a secant curve or a cosecant curve with an asymptotic line at a predetermined rotation angle corresponding to the phase in which a failure of electric current flow has occurred, and the motor control signal generating section generates a motor control signal for energizing the other two phases than the phase in which the failure of electric current flow has occurred, by executing a phase electric current feedback control on the basis of the calculated phase electric current command value, and

wherein the anomaly detecting section executes the anomaly detection of the control system on the basis of a phase electric current deviation of at least one of two phases in which the failed electric current flow is not generated, in the case of detecting that a failure of electric current flow has occurred in any of the phases of the motor.

11. An electric power steering apparatus having the motor controller according to claim 10.

12. A motor controller comprising:

a motor control signal output section; and

a drive circuit feeding a three phase drive power to a motor on the basis of a motor control signal output from the motor control signal output section,

wherein the motor control signal output section includes;

an electric current command value calculating section;

a motor control signal generating section generating the motor control signal by executing an electric current feedback control on the basis of an electric current command value calculated by the electric current command value calculating section; and

an anomaly detecting section for detecting an anomaly of a control system and a failure of electric current flow in any of the phases of the motor,

wherein, in a case of detecting that the failure of electric current flow has occurred in any of the phases of the motor, the anomaly detecting section executes the anomaly detection of the control system on the basis of a total value of the phase electric current values of two phases in which the failure of electric current flow has not been occurred.

13. An electric power steering apparatus having the motor controller according to claim 12.