A motor controller executes an axis module for each of multiple motors coupled to a shared load. A first control module passes at least one state variable to a second control module without experiencing communication delays between the axis modules. In order to decouple interaction between axes, the first control module determines the desired state variable at a periodic update rate and stores the desired state variable in memory. The first control module provides an indication to the second control module that the desired state variable is available. Within the same period at which the desired state variable is determined, the second control module receives the indication that the desired state variable is available and reads the state variable from the memory of the controller. The second control module executes using the desired state variable to reduce coupling between the two control modules.

A controller includes a calculator, a generator, and an adjuster. The calculator calculates a correction value for a position command based on a transmission delay and a control delay included in outputting the position command from the controller to the slave axis drive. The transmission delay is a delay in transmitting the position command to the slave axis drive. The control delay is a delay in the slave axis drive. The generator generates a corrected position command by applying the correction value to a reference position command for the slave axis drive calculated using position information about the master axis drive. The adjuster adjusts, in a predetermined period from when a speed of the master axis drive changes, the correction value to be below a value calculated by the calculator to cause a position of the slave axis drive to avoid exceeding a position of the master axis drive.

A synchronization control device includes a command movement amount calculation unit, a predicted command movement amount calculation unit, and a movement amount comparison unit for comparing a command movement amount with a predicted command movement amount, and synchronization of a driven shaft is not started when the predicted command movement amount is less than the command movement amount, and synchronization is started when the predicted command movement amount is equal to or greater than the command movement amount.

A multi-axis motor synchronization control system is provided, which may include a plurality of driving axes and the driving axes are coupled to one another; each of the driving axes may include a position loop controller, a velocity loop controller, a motor and a synchronization calibration device. The position loop controller may generate a velocity signal according to a position command. The velocity loop controller may generate a velocity command according to the velocity signal. The motor may operate according to the velocity command. The synchronization calibration device may calculate the average value of the position signal of the motor and the position signals of the motors of the adjacent driving axes, and then feedback the average value to the position loop controller so as to perform the synchronization calibration.

A numerical controller outputs a position command corresponding to a synchronous position in consideration of a servo delay of a slave axis, to the slave axis from a real position of a master axis, in order to perform position control of the slave axis, thereby making a real position of the slave axis synchronously follow the real position of the master axis. A position control gain of the slave axis is changed based on a predetermined physical quantity during the synchronous control and a compensation value for the position command for the slave axis is varied depending on the amount of change of the position control gain of the slave axis.