Motor control device

• US 9,459,598 B2
• Filed: 12/19/2014
• Issued: 10/04/2016
• Est. Priority Date: 12/19/2013
• Status: Active Grant

• Current Assignee: Okuma Corporation
• Original Assignee: Okuma Corporation
• Inventors: Kigaku, Kazushige, Kameyama, Tomohisa
• Primary Examiner(s): FLETCHER, MARLON T
• Application Number:
  US14/576,600
• Publication Number:
  US 20150177710A1
• Time in Patent Office: 655 Days
• US Class Current: 1/1
• CPC Class Codes: G05B 11/36 with provision for obtaining particular characteristics, e.g. proportional, integral, differential
• CPC Class Codes: G05B 13/02 electric
• CPC Class Codes: G05B 13/024 in which a parameter or coefficient is automatically adjusted to optimise the performance
• CPC Class Codes: G05B 2219/41163 Adapt gain to friction, weight, inertia

Abstract

Control parameters such as an acceleration/deceleration time constant Tf, a position loop gain Kpf, a velocity loop proportional gain Pvf, and a velocity loop integral gain Ivf, each including respective values assigned to each of a plurality of different inertia values J₀˜J_max, are changed based on an inertia value J_x calculated by an inertia identifying unit and an adjusted control parameter calculated by an automatic control-parameter adjustment unit.

Claims

1. A control device, comprising:

a memory device having stored therein respective values of a control parameter for each of a plurality of different inertia values, as standard control parameter values; and

a control parameter setting unit configured to calculate, based on the standard control parameter values, a control parameter value corresponding to an inertia value of a control target, and configured to set the control parameter value;

wherein the control device is a device that is configured to control position and velocity of a motor in accordance with the control parameter value set by the control parameter setting unit,

wherein the control device further comprises;

an automatic control-parameter adjustment unit configured to drive the motor while using an adjustment control target, and configured to gradually alter a control parameter used for controlling position and velocity of the motor, and, based on a control error obtained at each instance the control parameter is altered, configured to identify a control parameter value suitable for the adjustment control target as an adjusted control parameter; and

a control parameter changing unit configured to change the standard control parameter values based on the adjusted control parameter and an inertia value of the adjustment control target.

2. The control device according to claim 1, wherein

the control parameter changing unit is configured to

(i) calculate, based on the standard control parameter values, a control parameter value corresponding to the inertia value of the adjustment control target, as a reference control parameter,

(ii) calculate a reference difference value between the adjusted control parameter and the reference control parameter corresponding to the inertia value of the adjustment control target,

(iii) calculate, based on the reference difference value, adjusted difference values corresponding to the plurality of different inertia values, and

(iv) calculate, as new standard control parameter values, values corresponding to the standard control parameter values by applying the adjusted difference values.

3. The control device according to claim 2, wherein the control parameter changing unit is configured to:

if the standard control parameter values to be changed are values of a control parameter that varies in proportion to inertia values, calculate the adjusted difference values to be a constant value, and

if the standard control parameter values to be changed are values of a control parameter that does not vary in proportion to inertia values, calculate the adjusted difference values to be variable values that differ depending on the inertia values.

4. The control device according to claim 2, wherein

if the standard control parameter values to be changed are values of a control parameter that varies in proportion to inertia values, the reference difference value is the adjusted difference values.

5. The control device according to claim 2, wherein, if the standard control parameter values to be changed are values of a control parameter that does not vary in proportion to inertia values,

(i) the adjusted difference values corresponding to a maximum inertia value and a minimum inertia value among the plurality of different inertia values are zero,

(ii) absolute values of the adjusted difference values corresponding to inertia values between the inertia value of the adjustment control target and the maximum inertia value are values reduced from the reference difference value in proportion to the inertia values, and

(iii) absolute values of the adjusted difference values corresponding to inertia values between the inertia value of the adjustment control target and the minimum inertia value are values reduced from the reference difference value in proportion to the inertia values.