System and method including feed-forward control of a brushless synchronous motor
AssigneeOMAX Corporation
InventorsKevin Hay, Brian Guglielmetti
Life of this patent
Estimating the term…
Abstract
A drive system, such as for a fluid jet cutting system, includes a brushless synchronous motor configured to drive movement through a loosely coupled transmission, a sensor configured to sense movement, and a control system configured to drive the brushless synchronous motor responsive to previously measured drive coupling.
Claims43
A method for driving a brushless synchronous motor, comprising:
- receiving at least one command through a data interface to move a number of command increments;
- determining a ratio of motor increment per command increment;
- calculating from the ratio a number of motor increments corresponding to the number of command increments;
- outputting the number of motor increments to a brushless synchronous motor;
- monitoring a position encoder operatively coupled to a member driven by the brushless synchronous motor;
- and
- updating the ratio of motor increments per command increment if the position encoder indicates an error from an expected change in position.
A circuit for driving a brushless synchronous motor, comprising:
- a data source configured to provide data corresponding to an intended travel distance or an intended number of command increments for driving a brushless synchronous motor;
- a step ratio memory configured to hold data corresponding to a ratio of motor increment per unit distance or a ratio of motor increment per command increment;
- an increment calculator configured to calculate a number of motor increments as a function of data from the data source and data from the step ratio memory;
- and
- a motor drive port configured to output the number of motor increments.
An apparatus, comprising:
- a carriage configured to travel along a rail;
- a brushless synchronous motor configured to drive the carriage along the rail with an imperfectly coupled drive transmission;
- a sensor configured to sense the travel distance or position of the carriage along the rail;
- a data source configured to provide input data corresponding to an intended travel distance or position for the carriage along the rail;
- and
- a motor drive circuit configured to determine at least one ratio between intended travel distance or position and actual travel distance or actual position, and drive the brushless synchronous motor responsive to the input data and the ratio.
A tangible computer-readable medium carrying computer instructions configured to cause a computer to:
- receive a command increment value;
- calculate a motor increment value from the command increment value and a step ratio;
- drive a motor drive according to the motor increment value;
- observe the motor increment value and a feedback value corresponding to actual movement produced by a brushless synchronous motor operatively coupled to the motor drive;
- and
- modify the step ratio responsive to a difference between the motor increment value and the feedback value.
A method for driving a brushless synchronous motor, comprising:
- receiving a command increment value;
- calculating a motor increment value from the command increment value and a step ratio;
- driving a motor drive according to the motor increment value;
- observing the motor increment value and a feedback value corresponding to actual movement produced by a brushless synchronous motor operatively coupled to the motor drive;
- and
- modifying the step ratio responsive to a difference between the motor increment value and the feedback value.
Dependencies are inferred from the claim text.