Frequency characteristic identifying method and drive controlling apparatus
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorEiji Hayashi
Life of this patent
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Abstract
An instruction value is added to a specific signal to produce an added signal. A servo motor is driven based on this added signal. The response of the motor is measured while the motor is being driven. A characteristic value calculated based on the response is compared with a reference value. When the characteristic value is significantly smaller than the reference value, the amplitude of the specific signal is changed so that the characteristic value converges to the reference value. When the characteristic value has almost converged to the reference value, frequency characteristics can be identified accurately.
Claims14
A frequency characteristic identifying method executable in a drive controlling apparatus that controls driving of a servo motor, the method comprising:
- receiving an instruction value;
- generating as a signal one of (i) a sequential signal including sequential sine waves with different frequencies and identical amplitudes, and (ii) a superimposed signal including a plurality of superimposed signals having different frequencies and identical amplitudes;
- adding the instruction value to the signal generated to produce an added signal;
- driving a servo motor based on the added signal;
- measuring a parameter of the servo motor while the servo motor is being driven;
- calculating a characteristic value based on the parameter measured;
- calculating a difference between the characteristic value and a reference value;
- determining whether the difference is within a range;
- and
- when the difference is not within the range, changing amplitude of the signal generated so that the characteristic value converges to the reference value.
A drive controlling apparatus controlling a servo motor comprising:
- a signal generator which generates as a signal one of (i) a sequential signal including sequential sine waves with different frequencies and identical amplitudes, and (ii) a superimposed signal including a plurality of superimposed signals having different frequencies and identical amplitudes;
- an adder which adds the signal generated by the signal generator to an instruction value to produce an added signal;
- a controller which controls a servo motor based on the added signal;
- a sensor which measures a parameter of the servo motor;
- and
- a signal comparator which
- calculates a characteristic value based on the parameter
- calculates a difference between the characteristic value and a reference value,
- determines whether the difference is within a range, and
- outputs whether the difference is within the range to the signal generator, wherein the signal generator changes amplitude of the signal generated when the difference is outside the range, so that the characteristic value converges to the reference value.
Dependencies are inferred from the claim text.