Abnormality monitoring device for motor control system

• US 20060018636A1
• Filed: 07/25/2005
• Published: 01/26/2006
• Est. Priority Date: 07/23/2004
• Status: Active Grant

• Current Assignee: Yamaha Motor Company Limited (Yamaha Corporation)
• Original Assignee: Yamaha Motor Company Limited (Yamaha Corporation)
• Inventors: Watanabe, Hiroto, Uchiyama, Mikiyasu, Kishi, Tomoaki
• Granted Patent: US 7,260,319 B2
• Time in Patent Office: Days
• US Class Current: 388/804
• CPC Class Codes: F02D 11/107 Safety-related aspects
• CPC Class Codes: F02D 2041/2027 Control of the current by pulse width modulation or duty cycle control
• CPC Class Codes: F02D 41/221 relating to the failure of actuators or electrically driven elements
• CPC Class Codes: H02P 29/02 Providing protection against overload without automatic interruption of supply protection against faults of stepper motors H02P8/36
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

An abnormality monitoring device monitors a PWM driving signal output from a driving section of an associated motor control system to judge whether the driving section is operating abnormally. By monitoring the output of the driving section, the monitoring device can detect an abnormality of the driving section before the motor can respond to the abnormal drive signal to a significant degree (e.g., to a degree readily discernable to a rider of a motorcycle on which the motor control system is employed in combination with an electronic throttle system).

Claims

1. An abnormality monitoring device for an motor control system, comprising:

a control section configured to generate a PWM control signal to control a motor;

a driving section configured to generate a PWM driving signal based on the PWM control signal to drive the motor;

a counting section configured to count pulse periods of the PWM driving signal output from the driving section; and

an abnormality judging section configured to determine whether the driving section is functioning abnormally based on the PWM control signal and a counting result produced by the counting section.

2. An abnormality monitoring device for a motor control system, comprising:

a control section which generates a PWM control signal to control a motor;

a driving section which generates a PWM driving signal based on the PWM control signal to drive the motor;

an edge detecting section which detects at least one edge of each pulse of the PWM driving signal output from the driving section;

a counting section which counts an edge period of the detected edge of each pulse detected by the edge detecting section;

a monitoring time setting section which sets a monitoring time to monitor the edge period based on the PWM control signal;

an edge period comparing section which compares the edge period counted by the counting section with the monitoring time set by the monitoring time setting section; and

an abnormality judging section which judges whether or not the driving section is abnormal based on a comparison result of the comparing section.

3. The abnormality monitoring device for the motor control system according to claim 2, wherein the monitoring time setting section sets the monitoring time to be not less than the PWM period set in accordance with the PWM control signal.

4. The abnormality monitoring device for the motor control system according to claim 2, wherein the control section sets a control range of the target duty value to be greater than 0% and be less than 100%, and the abnormality judging section judges that the driving section is abnormal when the edge is not detected by the edge detecting section and the counting result of the counting section exceeds the monitoring time input from the monitoring time setting section.

5. The abnormality monitoring device for the motor control system according to claim 2, wherein the control section sets a control range of the target duty value to 0% or more and 100% or less, and the abnormality judging section judges that driving section is abnormal when edge is not detected by the edge detecting section and the counting result of the counting section exceeds the monitoring time, in a case where the target duty value is 0% or 100%.

6. The abnormality monitoring device for the motor control system according to claim 2, wherein the abnormality judging section outputs an abnormality signal to the control section when judging that the driving section is abnormal, and the control section detects the abnormality of the driving section based on the abnormality signal output from the abnormality judging section.

7. The abnormality monitoring device for the motor control system according to claim 2, wherein prior to start of the PWM control of the motor by the control section, the abnormality judging section judges whether operations of the edge period comparing section, the edge detecting section, the monitoring time setting section, and the counting section are normal or abnormal based on whether or not the counting result of the counting section exceeds the monitoring time in a case where an edge is not detected by the edge detecting section.

8. An abnormality monitoring device for a motor control system, comprising:

a control section which generates a PWM control signal to PWM-control a motor;

a driving section which generates a PWM driving signal based on the PWM control signal to drive the motor;

an edge detecting section which detects a rising (or falling) edge of each pulse of the PWM driving signal output from the driving section;

a counting section which counts an edge period of the rising (or falling) edge of each pulse detected by the edge detecting section;

a monitoring time setting section which sets a monitoring time to monitor the edge period based on the PWM control signal;

an edge period comparing section which compares the edge period counted by the counting section with the monitoring time set by the monitoring time setting section;

a duty detecting section which detects a duty value of the PWM driving signal based on the edge period counted by the counting section;

a duty comparing section which compares the duty value detected by the duty detecting section with a target duty value set in accordance with the PWM control signal; and

an abnormality judging section which judges whether or not the driving section is abnormal based on comparison results of the edge period comparing section and the duty comparing section.

9. The abnormality monitoring device for the motor control system according to claim 8, wherein the monitoring time setting section sets the monitoring time to be not less than the PWM period set in accordance with the PWM control signal.

10. The abnormality monitoring device for the motor control system according to claim 8, wherein the control section sets a control range of the target duty value to be greater than 0% and be less than 100%, and the abnormality judging section judges that the driving section is abnormal when the edge is not detected by the edge detecting section and the counting result of the counting section exceeds the monitoring time input from the monitoring time setting section.

11. The abnormality monitoring device for the motor control system according to claim 8, wherein the control section sets a control range of the target duty value to 0% or more and 100% or less, and the abnormality judging section judges that driving section is abnormal when edge is not detected by the edge detecting section and the counting result of the counting section exceeds the monitoring time, in a case where the target duty value is 0% or 100%.

12. The abnormality monitoring device for the motor control system according to claim 8, wherein the abnormality judging section judges that the driving section is abnormal in a case where there is a difference which is not less than a certain value between the detected duty value and the target duty value.

13. The abnormality monitoring device for the motor control system according to claim 8, wherein the abnormality judging section outputs an abnormality signal to the control section when judging that the driving section is abnormal, and the control section detects the abnormality of the driving section based on the abnormality signal output from the abnormality judging section.

14. The abnormality monitoring device for the motor control system according to claim 8, wherein prior to start of the PWM control of the motor by the control section, the abnormality judging section judges whether operations of the edge period comparing section, the edge detecting section, the monitoring time setting section, and the counting section are normal or abnormal based on whether or not the counting result of the counting section exceeds the monitoring time in a case where an edge is not detected by the edge detecting section.

15. An abnormality monitoring program for a motor control system that includes a control section which generates a PWM control signal to control a motor and a driving section which generates a PWM driving signal based on the PWM control signal to drive the motor, the program comprising the steps of:

detecting an edge of each pulse of the PWM driving signal;

counting an edge period of the edge of each detected pulse;

setting a monitoring time to monitor the edge period based on the PWM control signal;

comparing the counted edge period with the set monitoring time; and

judging an abnormality of the driving section based on the comparison result.

16. An abnormality monitoring program for a motor control system that includes a control section which generates a PWM control signal to control a motor and a driving section which generates a PWM driving signal based on the PWM control signal to drive the motor, the program comprising the steps of:

detecting a rising or falling edge of each pulse of the PWM driving signal;

counting an edge period of the rising or falling edge of each detected pulse;

a monitoring time setting step of setting a monitoring time to monitor the edge period based on the PWM control signal;

comparing the counted edge period with the set monitoring time;

a duty value of each pulse based on the counted edge period;

comparing the detected duty value with a target duty value set in accordance with the PWM control signal; and

judging whether or not the driving section is abnormally operating based on comparison results of time and duty value.