Servo controller

• US 6,252,367 B1
• Filed: 01/10/2000
• Issued: 06/26/2001
• Est. Priority Date: 01/11/1999
• Status: Expired due to Term

• Current Assignee: Fanuc Ltd (Fanuc Corporation)
• Original Assignee: Fanuc Ltd (Fanuc Corporation)
• Inventors: Takahashi, Kenji, Toyosawa, Yukio, Sakamoto, Keiji
• Primary Examiner(s): Nappi, Robert E.
• Assistant Examiner(s): SMITH, TYRONE W
• Application Number:
  US09/479,998
• Time in Patent Office: 533 Days
• Field of Search: 318/700, 318/713, 318/807, 318/809, 318/801, 318/560
• US Class Current: 318/560
• CPC Class Codes: G05B 19/39 using a combination of the means covered by at least two of the preceding groups G05B19/21, G05B19/27 and G05B19/33
• CPC Class Codes: G05B 2219/42129 Teach, learn position table, model, for each reference a motor control output

Abstract

A servo controller capable of controlling motors to be driven in different control modes, such as a synchronous motor and an induction motor, irrespectively of the type of the motor, and also capable of carrying out servo control by using incremental feedback signals. A control section common to individual motors and a control section dedicated to each motor are provided in a servo controller. The common control section is always used, while the dedicated control section is selectively used in accordance with the motor to be driven. Thereby, motors each requiring a different control mode can be controlled by the servo controller of one type. The use of th servo controller of one type can reduce maintenance management and a load on a CNC. Also, the provision of the control section common to individual motors can restrain increases of size, installation area and manufacturing cost of the device.

Claims

1. A servo controller comprising:

a common control section for performing control common to an induction motor and an synchronous motor, said common control section including a position controller, a velocity controller and a current controller;

a first dedicated control section for performing control dedicated to the induction motor, and a second dedicated control section for performing control dedicated to the synchronous motor, said first dedicated control section including a d-axis current command generator for calculating magnetic flux and magnetic flux current, and a slip command generator to generate a slip command for the induction motor, said second dedicated control section including a d-axis current command generator to set a d-axis current command for the synchronous motor;

a position/velocity detecting section for detecting position/velocity of a motor to be driven based on signals from a sensor associated with the motor; and

a selecting section for selecting one of said first dedicated control section and said second dedicated control section, and driving parameter for the motor to be driven, based on attribution data preset for each motor,

thereby controlling the motor to be driven by a combination of said common control section, the selected dedicated control section and said position/velocity detecting section.

2. A servo controller according to claim 1, wherein said attribution data for each motor include data indicating kind and characteristic of each motor and/or the associated sensor, and are stored in the associated sensor and inputted into the servo controller from the associated sensor.

3. A servo controller according to claim 1, wherein said attribution data preset for each motor include data indicating kind and characteristic of each motor and/or each associated sensor, and are stored in a numerical controller and inputted into the servo controller from the numerical controller.

4. A servo controller according to claim 2 or 3, wherein a sensor for outputting incremental position signals is associated with each of the synchronous motor and the induction motor, said second dedicated control section comprises a magnetic-pole position determiner, and

when it is discriminated based on the attribution data that the motor to be controlled is the synchronous motor, said magnetic-pole position determiner moves the magnetic pole of the synchronous motor to a predetermined position according to an external input signal for preliminary determination of the magnetic pole, outputs a magnetic-pole determined state signal at the predetermined position to enable driving of the motor with the preliminary determination position as a reference magnetic pole position, starts driving of the motor in response to a velocity command or a position command and continues the driving after detection of an one-revolution signal preset at a zero degree position of the motor, with a position where the one-revolution signal is detected as the reference position of zero-degree, using a sensor-signal input circuit common to the induction motor and the synchronous motor.

5. A servo controller according to any one of claim 1, wherein said selecting section further comprises a selecting switch for connecting one motor selected to be driven from a plurality of motors with the servo controller based on an external switching signal.

6. A servo controller according to claim 5, wherein said attribution data for each motor includes data indicating kind and characteristic of each motor and/or the associated sensor, and are stored in the associated sensor and inputted into the servo controller from the associated sensor.

7. A servo controller according to claim 5, said attribution data preset for each motor including data indicating kind and characteristic of each motor and/or each associated sensor, and are stored in a numerical controller and inputted into the servo controller from the numerical controller.

8. A servo controller according to claim 6 or 7, wherein a sensor for outputting incremental position signals is associated with each of the synchronous motor and the induction motor, said second dedicated control section comprises a magnetic-pole position determiner, and

when it is discriminated based on the attribution data that the motor to be controlled is the synchronous motor, said magnetic-pole position determiner moves the magnetic pole of the synchronous motor to a predetermined position according to an external input signal for preliminary determination of the magnetic pole, outputs a magnetic-pole determined state signal at the predetermined position to enable driving of the motor with the preliminary determination position as a reference magnetic pole position, starts driving of the motor in response to a velocity command or a position command and continues the driving after detection of an one-revolution signal preset at a zero degree position of the motor, with a position where the one-revolution signal is detected as the reference position of zero-degree, using a sensor-signal input circuit common to the induction motor and the synchronous motor.