Tuned open-loop switched to closed-loop method for rapid point-to-point movement of a periodic motion control system

An apparatus for controlling a motor, comprising:

• means for generating an open loop command for moving the motor;
• means for generating a closed loop command for moving the motor to correct an error in the movement resulting from the open loop command;
• means for adjusting the open loop command based on the error in the movement of the motor, the means for adjusting including storage means for recording an open loop command characteristic value from a preceding open loop command used to move the motor in a preceding cycle, means for calculating a parameter for adjusting the open loop command based on the sensed error, and generator means for generating an open loop characteristic value by changing the open loop command characteristic from the storage unit based on the calculated parameter;
• switching means for outputting the open loop command for controlling the motor when switched to an open loop position and outputting the closed loop command for controlling the motor when switched to a closed loop position;
• and
• timing means for outputting an open loop timing signal for controlling the switching means to switch to the open loop position and outputting a closed loop timing signal for controlling the switching means to switch to the closed loop position.

A method of controlling a motor, comprising:

• controlling the motor in an open-loop control manner using an open-loop command to move the motor to a predetermined location, wherein the open-loop command is output when a switching unit is switched to an open loop position in response to an open loop timing signal;
• controlling the motor in a closed-loop manner using a closed-loop command to correct errors in the open-loop control, wherein the closed-loop command is output when a switching unit is switched to a closed loop position in response to a closed loop timing signal;
• determining errors in a position and velocity of the motor based on the closed-loop control;
• and
• determining, based on the position and velocity errors, an adjustment to the magnitude of an amplitude of the open-loop command for use in a subsequent open-loop control of the motor, wherein the determining an adjustment to the magnitude of the amplitude of the open-loop command includes calculating, based on the determined errors, a parameter for use in adjusting the magnitude of the amplitude of the open-loop command, and adjusting the magnitude of the amplitude of the open-loop command based on the calculated parameter, wherein the calculated parameter is an amplitude change ΔA calculated according to ΔA=e*ΔPf+f*ΔVf, where e and f are constants, ΔPf is a change in the motor's final position following the closed-loop control and the motor's final position upon completion of a closed-loop control operation in a preceding cycle, and ΔVf is the change in the motor's final velocity following the closed-loop control and the motor's final velocity upon completion of a closed-loop control operation in said preceding cycle.

A method of controlling a motor, comprising:

• controlling the motor in an open-loop control manner using an open-loop command to move the motor to a predetermined location, wherein the open-loop command is output when a switching unit is switched to an open loop position in response to an open loop timing signal;
• controlling the motor in a closed-loop manner using a closed-loop command to correct errors in the open-loop control, wherein the closed-loop command is output when a switching unit is switched to a closed loop position in response to a closed loop timing signal;
• determining errors in a position and velocity of the motor based on the closed-loop control;
• and
• determining, based on the position and velocity errors, an adjustment to the magnitude of an amplitude of the open-loop command for use in a subsequent open-loop control of the motor, wherein the determining an adjustment to the magnitude of the amplitude of the open-loop command includes
• calculating, based on the determined errors, a parameter for use in adjusting the magnitude of the amplitude of the open-loop command;
• and
• adjusting the magnitude of the amplitude of the open-loop command based on the calculated parameter,
• wherein the calculated parameter is a shift in area of the open-loop command, the shift in area of the open loop command ΔS being calculated according to ΔS=g*ΔPf+h*ΔVf, where g and h are predetermined constants, ΔPf is a change in the motor's final position following the closed-loop control and the motor's final position upon completion of a closed-loop control operation in a preceding cycle, and ΔVf is a change in final velocity between the motor's final velocity upon completion of a closed-loop operation and the final velocity upon completion of a closed-loop operation in said preceding cycle.

A computer program embodied on a computer-readable medium, for controlling a motor, the computer program comprising:

• program instructions for controlling the motor in an open-loop control manner using an open-loop command to move the motor to a predetermined location, wherein the open-loop command is output when a switching unit is switched to an open loop position in response to an open loop timing signal;
• program instructions for controlling the motor in a closed-loop manner using a closed-loop command to correct errors in the open-loop control, wherein the closed-loop command is output when a switching unit is switched to a closed loop position in response to a closed loop timing signal;
• program instructions for determining errors in a position and velocity of the motor based on the closed-loop control;
• and
• program instructions determining, based on the position and velocity errors, an adjustment to the magnitude of an amplitude of the open-loop command for use in a subsequent open-loop control of the motor, wherein the program instructions for determining the adjustment to the magnitude of the amplitude of the open-loop command includes program instructions for calculating, based on the determined errors, a parameter for use in adjusting the magnitude of the amplitude of the open-loop command, and program instructions for adjusting the magnitude of the amplitude of the open-loop command based on the calculated parameter, wherein the calculated parameter is an amplitude change ΔA calculated according to ΔA=e*ΔPf+f*ΔVf, where e and f are constants, ΔPf is a change in the motor's final position following the closed-loop control and the motor's final position upon completion of a closed-loop control operation in a preceding cycle, and ΔVf is the change in the motor's final velocity following the closed-loop control and the motor's final velocity upon completion of a closed-loop control operation in said preceding cycle.

A computer program embodied on a computer-readable medium, for controlling a motor, the computer program comprising:

• program instructions for controlling the motor in an open-loop control manner using an open-loop command to move the motor to a predetermined location, wherein the open-loop command is output when a switching unit is switched to an open loop position in response to an open loop timing signal;
• program instructions for controlling the motor in a closed-loop manner using a closed-loop command to correct errors in the open-loop control, wherein the closed-loop command is output when a switching unit is switched to a closed loop position in response to a closed loop timing signal;
• program instructions for determining errors in a position and velocity of the motor based on the closed-loop control;
• and
• program instructions determining, based on the position and velocity errors, an adjustment to the magnitude of an amplitude of the open-loop command for use in a subsequent open-loop control of the motor, wherein the program instructions for determining the adjustment to the magnitude of the amplitude of the open-loop command includes program instructions for calculating, based on the determined errors, a parameter for use in adjusting the magnitude of the amplitude of the open-loop command;
• and program instructions for adjusting the magnitude of the amplitude of the open-loop command based on the calculated parameter, wherein the calculated parameter is a shift in area of the open-loop command.