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US 12,386,336 B2Granted
Servo control apparatus and servo control method
AssigneeOkuma Corporation
InventorRiku Ikegami
Life of this patent
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Abstract
A servo control apparatus includes an actual machine frequency characteristic measurer that calculates a frequency characteristic of an actual machine from a motor input signal and an output of a detector, and a parameter adjuster that finds a solution for a parameter of a controller, which sets a difference, between an open loop characteristic, calculated from a calculation result of the actual machine frequency characteristic measurer and a frequency characteristic of the controller, and an ideal open loop characteristic, to be less than or equal to a predefined reference, and that applies the obtained parameter to the controller.
Claims3
A servo control apparatus which drives a load device by a servo motor, the servo control apparatus comprising:
- a command generator that generates a command value of the servo motor;
- a detector that detects a state quantity of the servo motor or the load device to be driven;
- a controller that controls a motor input signal such that the command value and an output of the detector coincide with each other;
- an actual machine frequency characteristic measurer that calculates a frequency characteristic of an actual machine from the motor input signal and the output of the detector;
- and
- a parameter adjuster that finds a solution for a parameter of the controller, which sets a difference, between an open loop characteristic, calculated from a calculation result of the actual machine frequency characteristic measurer and a frequency characteristic of the controller, and an ideal open loop characteristic, to be less than or equal to a predefined reference, or to be a minimum, and that applies the obtained parameter to the controller,
- wherein
- when the actual machine frequency characteristic measurer calculates the frequency characteristic of the actual machine, the actual machine frequency characteristic measurer changes a position of the load device to an arbitrary position and calculates a frequency characteristic of the actual machine for each position,
- parameters of the controller are a plurality of variables included in a formula that represents the controller,
- the ideal open loop characteristic is represented by a formula that includes a predefined coefficient and a Laplacian operator as elements, the formula being one formula determined based on a performance demanded by a designer for the controller,
- the parameter adjuster applies the controller to individual actual machine frequencies corresponding to multiple positions to calculate a plurality of open loop characteristics,
- the parameter adjuster obtains a combination of the plurality of variables such that the sum of differences between each of the plurality of open loop characteristics and the ideal open loop characteristic is less than or equal to a predefined reference value, or is a minimum, and
- the parameter adjuster applies the obtained variables to the controller as the parameters of the controller.
10 more elements
A servo control method for driving a load device by a servo motor, the method comprising:
- operating the servo motor according to a command value;
- detecting, with a detector, a state quantity of the servo motor or the load device to be driven;
- controlling, with a controller, a motor input signal so that the command value and an output of the detector coincide with each other;
- calculating a frequency characteristic of an actual machine from the motor input signal and the output of the detector;
- and
- finding a solution for a parameter of the controller, which sets a difference, between an open loop characteristic, calculated from the frequency characteristic of the actual machine and a frequency characteristic of the controller, and an ideal open loop characteristic, to be less than or equal to a predefined reference, or to be a minimum, and applying the obtained parameter to the controller, wherein
- the calculating a frequency characteristic of an actual machine comprises changing a position of the load device to an arbitrary position and calculating a frequency characteristic of the actual machine for each position,
- parameters of the controller are a plurality of variables included in a formula that represents the controller,
- the ideal open loop characteristic is represented by a formula that includes a predefined coefficient and a Laplacian operator as elements, the formula being one formula determined based on a performance demanded by a designer for the controller,
- the finding a solution comprises applying the controller to individual actual machine frequencies corresponding to multiple positions to calculate a plurality of open loop characteristics,
- the finding a solution comprises obtaining a combination of the plurality of variables such that the sum of differences between each of the plurality of open loop characteristics and the ideal open loop characteristic is less than or equal to a predefined reference value, or is a minimum, and
- the finding a solution comprises applying the obtained variables to the controller as the parameters of the controller.
9 more elements
Dependencies are inferred from the claim text.