Position control system and velocity control system for stage driving mechanism

A position control system of a stage driving mechanism which drives a stage at least in one-axial direction, the position control system comprising:

• a position detector for detecting a position of the stage;
• and
• a feedback control system for controlling a linear motor, which is a driving source of the stage, on the basis of a detected positional value obtained from the position detector and a positional command value, the feed back control system comprising the position detector, a first calculator for calculating a first difference between the detected positional value and the positional command value, a Proportional Integral Derivative (PID) controller connected to the first calculator for generating a current target value for the linear motor from the first difference, and a motor drive connected to the PID controller for generating a torque command value for the linear motor, and
• wherein the position control system further comprises:
• a second calculator inserted and connected between the PID controller and the motor drive source;
• and
• a disturbance observer connected to the output side of the second calculator, the output side of the position detector, and one input side of the second calculator, the disturbance observer comprising a signal processing unit for carrying out high-speed calculation according to a predetermined program,
• wherein the signal processing unit comprises:
• a low-pass filter for filtering the torque command value for the linear motor;
• an input torque estimating filter carrying out estimation for obtaining an estimated input load torque from the detected positional value;
• a third calculator for calculating a third difference between the filtered torque command value and the estimated input load torque;
• and
• an inverse model of a motor torque constant for calculating an estimated disturbance load torque from the third difference and for calculating a correction value for the current target value so as to cancel a disturbance torque by multiplying the estimated disturbance load torque calculated above by an inverse number of the motor torque constant, and
• wherein the second calculator calculates a second difference by subtracting the current target value of the PID controller from the correction value of the inverse model of the motor torque constant and produces the second difference to the motor drive as a current command value.

A velocity control system of a stage driving mechanism which drives a stage at least in one-axial direction, the velocity control system comprising:

• a velocity detector for detecting a velocity of the stage;
• a feedback control system for controlling a motor, which is a driving source of the stage, on the basis of a detected velocity value obtained from the velocity detector and a velocity command value;
• a Proportional Integral Derivative (PID) controller for generating a current target value for the motor from the difference between the detected velocity value and the velocity command value;
• and
• a disturbance observer comprising a signal processing unit for carrying out high-speed calculation according to a predetermined program,
• wherein the signal processing unit has a filtering function to filter a torque command value for the motor, an input torque estimating and filtering function carrying out estimation for obtaining an estimated input load torque from the detected velocity value, and a function to calculate an estimated disturbance load torque from the difference between the filtered torque command value and the estimated input load torque and to calculate a correction value for the current target value so as to cancel a disturbance torque by multiplying the estimated disturbance load torque calculated above by an inverse number of a motor torque constant.

A velocity control system of a stage driving mechanism which drives a stage at least in one-axial direction, the velocity control system comprising:

• a velocity detector for detecting a velocity of the stage;
• and
• a feedback control system for controlling a linear motor, which is a driving source of the stage, on the basis of a detected velocity value obtained from the velocity detector and a velocity command value, the feedback control system comprising the velocity detector, a first calculator for calculating a first difference between the detected velocity value and the velocity command value, a Proportional Integral Derivative (PID) controller connected to the first calculator for generating a current target value for the linear motor from the first difference, and a motor drive connected to the PID controller for generating a torque command value for the linear motor, and
• wherein the velocity control system further comprises:
• a second calculator inserted and connected between the PID controller and the motor drive;
• and
• a disturbance observer connected to the output side of the second calculator, the output side of the position detector, and one input side of the second calculator, the disturbance observer comprising a signal processing unit for carrying out high-speed calculation according to a predetermined program,
• wherein the signal processing unit comprises:
• a low-pass filter for filtering the torque command value for the linear motor;
• an input torque estimating filter carrying out estimation for obtaining an estimated input load torque from the detected velocity value;
• a third calculator for calculating a third difference between the filtered torque command value and the estimated input load torque;
• and
• an inverse model of a motor torque constant for calculating an estimated disturbance load torque from the third difference and for calculating a correction value for the current target value so as to cancel a disturbance torque by multiplying of the estimated disturbance load torque calculated above by an inverse number of the motor torque constant, and
• wherein the second calculator calculates a second difference by subtracting the correction value of the inverse model of the motor torque constant from the current target value of the PID controller.

A position control system of a stage driving mechanism which drives a stage at least in one-axial direction, the position control system comprising:

• a position detector for detecting a position of the stage;
• and
• a feedback control system for controlling a motor, which is a driving source of the stage, on the basis of a detected positional value obtained from the position detector and a positional command value, the feed back control system comprising the position detector, a first calculator for calculating a first difference between the detected positional value and the positional command value, a Proportional Integral Derivative (PID) controller connected to the first calculator for generating a current target value for the motor from the first difference, and a motor drive connected to the PID controller for generating a torque command value τc for the motor, and
• wherein the position control system further comprises:
• a second calculator inserted and connected between the PID controller and the motor drive;
• and
• a disturbance observer connected to the output side of the second calculator, the output side of the position detector, and one input side of the second calculator, the disturbance observer comprising a signal processing unit for carrying out high-speed calculation according to a predetermined program,
• wherein the signal processing unit comprises:
• a low-pass filter for calculating the torque command value τc by multiplying a current command value ir for the motor by a motor torque constant Kt and for filtering the calculated torque command value;
• an input torque estimating filter for calculating an estimated input load torque from the detected positional value on the basis of an inverse model Jnoms2 of a transfer function 1/Js2 from the input torque of the mechanism including the motor and the load to the position;
• a third calculator for calculating a third difference between the filtered torque command value and the estimated input load torque;
• and
• an inverse model of the motor torque constant Kt for calculating an estimated disturbance load torque from the third difference and for calculating a correction value for the current target value so as to cancel a disturbance torque by multiplying the estimated disturbance load torque calculated above by an inverse number 1/Kt of the motor torque constant Kt, and
• wherein the second calculator calculates a second difference by subtracting the output value of the PID controller from the output value of the inverse model of the motor torque constant and produces the second difference to the motor drive as the current command value ir.

A velocity control system of a stage driving mechanism which drives a stage at least in one-axial direction, the velocity control system comprising:

• a velocity detector for detecting a velocity of the stage;
• and
• a feedback control system for controlling a motor, which is a driving source of the stage, on the basis of a detected velocity value obtained from the velocity detector and a velocity command value, the feed back control system comprising the velocity detector, a first calculator for calculating a first difference between the detected velocity value and the velocity command value, a Proportional Integral Derivative (PID) controller connected to the first calculator for generating a current target value for the motor from the first difference, and a motor drive connected to the PID controller for generating a torque command value τc for the motor, and
• wherein the velocity control system further comprises:
• a second calculator inserted and connected between the PID controller and the motor drive;
• and
• a disturbance observer connected to the output side of the second calculator, the output side of the velocity detector, and one input side of the second calculator, the disturbance observer comprising a signal processing unit for carrying out high-speed calculation according to a predetermined program,
• wherein the signal processing unit comprises:
• a low-pass filter for calculating the torque command value τc by multiplying a current command value ir for the motor by a motor torque constant Kt and for filtering the calculated torque command value;
• an input torque estimating filter for calculating an estimated input load torque from the detected velocity value on the basis of an inverse model Jnoms2 of a transfer function 1/Js2 from the input torque of the mechanism including the motor and the load to the position;
• a third calculator for calculating a third difference between the filtered torque command value and the estimated input load torque;
• and
• an inverse model of the motor torque constant Kt for calculating an estimated disturbance load torque from the third difference and for calculating a correction value for the current target value so as to cancel a disturbance torque by multiplying the estimated disturbance load torque calculated above by an inverse number 1/Kt of the motor torque constant Kt, and
• wherein the second calculator calculates a second difference by subtracting the output value of the inverse model of the motor torque constant from the output value of the PID controller and produces the second difference to the motor drive as the current command value ir.