Boots – shoes – and leggings
Patent
1991-02-27
1994-02-22
Ruggiero, Joseph
Boots, shoes, and leggings
318561, 364174, 36447412, 36447415, 395 61, 395900, 395904, G05B 1302, G06F 1500
Patent
active
052893677
DESCRIPTION:
BRIEF SUMMARY
DESCRIPTION
1. Technical Field
The present invention relates to a numerical control apparatus for adaptively controlling a servo apparatus such as a spindle motor, and more particularly, to a numerical control apparatus having a fuzzy control means.
2. Background Art
As a system for adaptively controlling a servo apparatus such as a spindle motor, for example, a system is known that utilizes a programmable machine controller (hereinafter, referred to as simply "a PMC", when applicable) which is substantially a self-contained PC (programmable controller) built into a numerical control apparatus.
FIG. 5 explains a system for adaptively controlling a spindle motor. In FIG. 5, the axis of abscissa represents a time and the axis of ordinate represents a load current in a spindle motor. During the time interval Ta in which a load current curve Is is higher than the upper limit Lu, the PMC lowers a spindle override and reduces the rotational speed (velocity) of the spindle motor. In the time interval Tb in which the load current Is is below the lower limit Ls, the PMC raises the override for the spindle motor to increase the velocity thereof. Thus, the PMC effects the adaptive control in such a way that the load current in the spindle motor is set to the reference value Lr, i.e., a constant load is obtained.
In the case of such an adaptive control using a PMC, however, a uniqueness control is performed in such a way that the load current is simply compared with the threshold limit values, and therefore, the override is frequently changed. As a result, a problem arises in that undesirable effects such as an unsatisfactory surface roughness, for example, may be caused by the adaptive control in some cases.
DISCLOSURE OF THE INVENTION
The present invention has been contrived in consideration of these circumstances, and an object thereof is to provide a numerical control apparatus in which a velocity of a spindle motor is smoothly controlled by a fuzzy control means.
To solve the above problem, according to the present invention, there is provided a numerical control apparatus for adaptively controlling a servo apparatus, characterized by comprising a fuzzy control means for effecting a fuzzy inference by receiving data of a load current and a velocity of the servo apparatus as a fuzzy input and outputting a velocity control signal for controlling the velocity of the servo apparatus.
The fuzzy control means receives the data of the load current and velocity of a servo apparatus such as a spindle motor, as an input, and then subjects the input to a fuzzy inference, to thereby produce a velocity control signal for controlling the velocity of the servo apparatus. The control of the servo apparatus with the resulting velocity control signal makes it possible to effect a smooth velocity control for the servo apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing hardware of a computerized numerical control apparatus for carrying out the present invention;
FIG. 2 illustrates an example of fuzzy rules;
FIGS. 3A-3O illustrate membership functions corresponding to the fuzzy rules illustrated in FIG. 2;
FIG. 4 is a graphical representation showing a sum of membership functions B1 through B5; and
FIG. 5 is a graphical representation explaining an adaptive control for a spindle motor.
BEST MODE OF CARRYING OUT THE INVENTION
One embodiment of the present invention will now be described with reference to the accompanying drawings.
FIG. 1 is a block diagram showing hardware of a computerized numerical control apparatus for carrying out the present invention. In FIG. 1, reference numeral 10 designates a computerized numerical control apparatus (hereinafter, referred to as simply "a CNC", when applicable), and a processor 11 serves as a central processor for the whole CNC. Namely, the processor 11 reads out a system program stored in a ROM 12 via a bus and executes the control for the whole CNC in accordance with the thus read out system program. Calculation data, display data and the like are tempor
REFERENCES:
patent: 3634664 (1972-01-01), Valek
patent: 4237408 (1980-12-01), Frecka
patent: 5012430 (1991-04-01), Sakurai
patent: 5025499 (1991-06-01), Inoue et al.
Li et al-"Developoment of Fuzzy Algorithms for Servo Systems"-IEEE Control Systems Magazine-Apr. 1989; pp. 65-71.
Sakai et al-"A Fuzzy Controller in Turning Process Automation"-Industrial Applications of Fuzzy Control-M. Sugeno (ED.)-Elsevier Science Publishers B.V. (North Holland), 1985.
Endo Takashi
Fujibayashi Kentaro
Sasaki Takao
Fanuc Ltd.
Ruggiero Joseph
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