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 obtain an added signal. Motor is driven based on this added signal. 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 a signal by sequentially outputting a sine wave with different frequencies or by superimposing a plurality of signals having different frequency but same amplitude;
- adding the instruction value and the generated signal to obtain an added signal;
- driving the 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 measured parameter;
- comparing the characteristic value and a reference value;
- and
- when the characteristic value is less than the reference value, changing an amplitude of the signal generated at the generating step such that the characteristic value converges to the reference value.
A drive controlling apparatus that controls a servo motor comprising:
- a signal generator which generates a signal by sequentially outputting a sine wave with different frequencies or by superimposing a plurality of signals having different frequency but same amplitude;
- an adder which adds the signal generated by the signal generator to an instruction value to obtain an added signal;
- a controller which controls the 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 and compares the characteristic value with a reference value,
- wherein the signal generator changes an amplitude of the generated signal, when the signal comparator decides that the characteristic value is less than the reference value, such that the characteristic value converges to the reference value.
Dependencies are inferred from the claim text.