Methods to improve the accuracy of easy servo system
The steps to improve the accuracy of the easy servo system as following:
1. Transmission clearance compensation
Improve the machine tool transmission components of the gear, screw manufacturing assembly accuracy and take measures to
eliminate the transmission gap,only reduce but can not completely eliminate the transmission gap.Mechanical transmission chain change movement or rotation direction,the beginning number of command pulses only can play a role in eliminating the gap,resulting in stepper motor idle,and the table without actual movement,leading to transmission error.
Compensation method: first measure and store the gap size, receive reverse displacement command,does not output to the stepper motor reverse displacement pulse,and convert the gap value to pulse number N,drive stepper motor to rotate,over the transmission gap,then follow the instruction pulse to act.
2. Pitch error compensation
The manufacturing error of the ball screw pitch in the transmission chain directly affects the displacement accuracy of the machine table.
Compensation method: set a number of compensation points, at each compensation point measure and record the table displacement
error,determine the compensation value and as a control parameter send to the NC device.When the equipment is running, the CNC will add compensation amount and compensate the pitch error after work table pass by each compensation station.
Micro-step drive:Driving method is to subdivide the stepper motor's step angle into several steps.