Motor controller

• US 6,157,156 A
• Filed: 06/18/1999
• Issued: 12/05/2000
• Est. Priority Date: 12/20/1996
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Yaskawa Denki
• Original Assignee: Kabushiki Kaisha Yaskawa Denki
• Inventors: Tsuruta, Kazuhiro
• Primary Examiner(s): IP, SHIK LUEN PAUL
• Application Number:
  US09/331,319
• Time in Patent Office: 536 Days
• Field of Search: 318/600-696, 318/701, 318/138, 318/254, 364/140-169
• US Class Current: 318/609
• CPC Class Codes: H02P 23/14 Estimation or adaptation of motor parameters, e.g. rotor time constant, flux, speed, current or voltage

Abstract

A motor control apparatus for adjusting a gain by identifying an inertia includes a speed control section for determining a torque command and controlling a speed of a motor such that an actual speed of the motor coincides with an inputted speed command; an estimation section for simulating and creating a model of the speed control section so that the motor speed coincides with the speed of the model; and an identifying section for identifying an inertia on a basis of a ratio between a first value which is obtained by time-integrating a first speed deviation of the speed control section during a specified period and a second value which is obtained by time-integrating a second speed deviation of the estimation section during the same period as the specified period, wherein identification of the inertia is performed only in a case where the motor speed within the speed control section and the speed of the model within the estimation section are not zero and coincide to each other, and the inertia is identified on a basis of a ratio between a first value which is obtained by time-integrating an absolute value of the first speed deviation of the speed control section during the specified period and a second value which is obtained by time-integrating an absolute value of the second speed deviation of the estimation section during the same period as the specified period.

Claims

1. A motor control apparatus comprising:

a speed control section for determining a torque command and controlling a speed of a motor such that an actual speed of said motor coincides with an inputted speed command;

an estimation section for simulating and creating a model of said speed control section so that the motor speed coincides with the speed of said model; and

an identifying section for identifying an inertia on a basis of a ratio between a first value which is obtained by time-integrating a first speed deviation of said speed control section during a specified period and a second value which is obtained by time-integrating a second speed deviation of said estimation section during the same period as said specified period, wherein

identification of the inertia is performed only in a case where the motor speed within said speed control section and the speed of said model within said estimation section are not zero and coincide to each other, and

the inertia is identified on a basis of a ratio between the first value which is obtained by time-integrating an absolute value of the first speed deviation of said speed control section during said specified period and the second value which is obtained by time-integrating an absolute value of the second speed deviation of said estimation section during the same period as said specified period.

2. The motor control apparatus according to claim 1, wherein at least two integrators for said speed control section are provided and are each used during a time period for obtaining the first value and at least two integrators for said estimation section are provided and are each used during a time period for obtaining the second value and wherein said at least two integrators for said speed control section are alternately changed over and said at least two integrators for said estimation section are alternately changed over so that alternate ones of said at least two integrators having completed the integration are cleared to zero before starting the time-integration of the absolute value of the speed deviations.

5. The motor control apparatus according to claim 1, wherein a proportional integral (PI) control method, an integral proportion (IP) control method, or a proportional integral and differential (PID) control method is used as a control method within said speed control section, and said first and second values are adjusted by the control gain of said adjusting section.

3. A motor control apparatus comprising:

a speed control section for determining a torque command and controlling a speed of a motor such that an actual speed of said motor coincides with an inputted speed command;

an estimation section for simulating and creating a model of said speed control section so that the motor speed coincides with the speed of said model;

an identifying section for identifying an inertia, only in a case where the motor speed within said speed control section and the speed of said model within said estimation section are not zero and coincide to each other, said inertia being identified on a basis of a ratio between a first value which is obtained by time-integrating during a specified period an absolute value of a value obtained by passing a first speed deviation of said speed control section through a predetermined filter and a second value which is obtained by time-integrating an absolute value of a second speed deviation of said estimation section during the same period as said specified period; and

an adjusting section for adjusting a control gain on a basis of a third value obtained by passing a ratio between the inertia identified within said identification section and an inertia within said estimation section through a predetermined filter.

4. The motor control apparatus according to claim 3, wherein said filter for passing the first speed deviation of said speed control section is a transfer function from the speed command to the motor speed of said speed control section.