摘要:
A stage assembly (220) for moving a device (200) includes a stage (208), and actuator pair (226) and a control system (224). The actuator pair (226) includes a first actuator (228) that is coupled to the stage (208). The first actuator (228) has a first E core (236) and a first I core (240) that is spaced apart a first gap (g1) from the first E core (236). The control system (224) directs current to the first actuator (228) to move the stage (208). In one embodiment, the amount of current directed to the first actuator (228) is determined utilizing a first parameter (a) that is added to the first gap (g1). The value of the first parameter (a) is determined by experimental testing. Additionally, the amount of current directed to the first actuator (228) can be determined utilizing a second parameter (b) that is added to the first gap (g1). The value of the second parameter (b) is determined by experimental testing.
摘要:
A stage assembly (220) for moving a device (200) includes a stage (208), and actuator pair (226) and a control system (224). The actuator pair (226) includes a first actuator (228) that is coupled to the stage (208). The first actuator (228) has a first E core (236) and a first I core (240) that is spaced apart a first gap (g1) from the first E core (236). The control system (224) directs current to the first actuator (228) to move the stage (208). In one embodiment, the amount of current directed to the first actuator (228) is determined utilizing a first parameter (a) that is added to the first gap (g1). The value of the first parameter (a) is determined by experimental testing. Additionally, the amount of current directed to the first actuator (228) can be determined utilizing a second parameter (b) that is added to the first gap (g1). The value of the second parameter (b) is determined by experimental testing.
摘要:
Methods, apparatus, and systems are disclosed for identifying force-ripple and/or side-forces in actuators used for moving a multiple-axis stage. The identified force-ripple and/or side-forces can be mapped, and maps of corresponding position-dependent compensation ratios useful for correcting same are obtained. The methods are especially useful for stages providing motion in at least one degree of freedom using multiple (redundant) actuators. In an exemplary method a stage member is displaced, using at least one selected actuator, multiple times over a set distance in the range of motion of the subject actuator(s). Each displacement has a predetermined trajectory and respective starting point in the range. For each displacement, respective section force-command(s) are extracted and normalized to a reference section force-command to define a section compensation-ratio. Multiple section compensation-ratios are assembled, as functions of displacement in the range, to provide a map of compensation ratios for the actuator(s) throughout the range.
摘要:
A method for determining a commutation offset for a mover (250A) of a mover assembly (220C) that moves and positions a stage (220A) relative to a stage base (220B) includes controlling the mover assembly (220C) in a closed loop fashion to maintain the position of the stage (220A) along a first axis and along a second axis with the stage (220A) levitated above the stage base (220B). The method also includes the steps of (i) directing current to a coil array (240) of the mover assembly (220C) so that the mover assembly (220C) imparts a disturbance on the stage (220A); and (ii) evaluating one or more forces generated by the mover assembly (220C) as a result of the disturbance on the stage (220A) created by the mover (250A). Further, a method for generating a compensation map (1402) includes sequentially directing a plurality of excitation signals to the control of the mover assembly (220C) and determining the control commands that result from the plurality of excitation signals.
摘要:
A method for determining a commutation offset for a mover (250A) of a mover assembly (220C) that moves and positions a stage (220A) relative to a stage base (220B) includes controlling the mover assembly (220C) in a closed loop fashion to maintain the position of the stage (220A) along a first axis and along a second axis with the stage (220A) levitated above the stage base (220B). The method also includes the steps of (i) directing current to a coil array (240) of the mover assembly (220C) so that the mover assembly (220C) imparts a disturbance on the stage (220A); and (ii) evaluating one or more forces generated by the mover assembly (220C) as a result of the disturbance on the stage (220A) created by the mover (250A). Further, a method for generating a compensation map (1402) includes sequentially directing a plurality of excitation signals to the control of the mover assembly (220C) and determining the control commands that result from the plurality of excitation signals.
摘要:
A method for determining a commutation offset for a mover (250A) of a mover assembly (220C) that moves and positions a stage (220A) relative to a stage base (220B) includes controlling the mover assembly (220C) in a closed loop fashion to maintain the position of the stage (220A) along a first axis and along a second axis with the stage (220A) levitated above the stage base (220B). The method also includes the steps of (i) directing current to a coil array (240) of the mover assembly (220C) so that the mover assembly (220C) imparts a disturbance on the stage (220A); and (ii) evaluating one or more forces generated by the mover assembly (220C) as a result of the disturbance on the stage (220A) created by the mover (250A). Further, a method for generating a compensation map (1402) includes sequentially directing a plurality of excitation signals to the control of the mover assembly (220C) and determining the control commands that result from the plurality of excitation signals.
摘要:
Methods, apparatus, and systems are disclosed for identifying force-ripple and/or side-forces in actuators used for moving a multiple-axis stage. The identified force-ripple and/or side-forces can be mapped, and maps of corresponding position-dependent compensation ratios useful for correcting same are obtained. The methods are especially useful for stages providing motion in at least one degree of freedom using multiple (redundant) actuators. In an exemplary method a stage member is displaced, using at least one selected actuator, multiple times over a set distance in the range of motion of the subject actuator(s). Each displacement has a predetermined trajectory and respective starting point in the range. For each displacement, respective section force-command(s) are extracted and normalized to a reference section force-command to define a section compensation-ratio. Multiple section compensation-ratios are assembled, as functions of displacement in the range, to provide a map of compensation ratios for the actuator(s) throughout the range.
摘要:
A method for determining a commutation offset for a mover (250A) of a mover assembly (220C) that moves and positions a stage (220A) relative to a stage base (220B) includes controlling the mover assembly (220C) in a closed loop fashion to maintain the position of the stage (220A) along a first axis and along a second axis with the stage (220A) levitated above the stage base (220B). The method also includes the steps of (i) directing current to a coil array (240) of the mover assembly (220C) so that the mover assembly (220C) imparts a disturbance on the stage (220A); and (ii) evaluating one or more forces generated by the mover assembly (220C) as a result of the disturbance on the stage (220A) created by the mover (250A). Further, a method for generating a compensation map (1402) includes sequentially directing a plurality of excitation signals to the control of the mover assembly (220C) and determining the control commands that result from the plurality of excitation signals.
摘要:
A stage assembly (220) that moves a work piece (200) about a first axis and along a first axis includes a first stage (238), a second stage (240) that retains the work piece (200), a second mover assembly (244), a measurement system, and an initialization system (1081A). The second mover assembly (244) moves the second stage (240) relative to the first stage (238) about the first axis. The measurement system (22) monitors the position of the second stage (240) about the first axis when the second stage (240) is positioned within a working range about the first axis. The initialization system (1081A) facilitates movement of the second stage (240) about the first axis when the second stage (240) is rotated about the first axis outside the working range. The second mover assembly (244) can include a mover (255) and a dampener (410) that reduces the transmission of vibration from the first stage (238) to the second stage (240). In addition, the stage assembly (220) can include a control system (24) that directs power to the mover (255) to position the second stage (240) and to compensate for vibration of the first stage (238).
摘要:
A stage assembly (220) that moves a work piece (200) about a first axis and along a first axis includes a first stage (238), a second stage (240) that retains the work piece (200), a second mover assembly (244), a measurement system, and an initialization system (1081A). The second mover assembly (244) moves the second stage (240) relative to the first stage (238) about the first axis. The measurement system (22) monitors the position of the second stage (240) about the first axis when the second stage (240) is positioned within a working range about the first axis. The initialization system (1081A) facilitates movement of the second stage (240) about the first axis when the second stage (240) is rotated about the first axis outside the working range. The second mover assembly (244) can include a mover (255) and a dampener (410) that reduces the transmission of vibration from the first stage (238) to the second stage (240). In addition, the stage assembly (220) can include a control system (24) that directs power to the mover (255) to position the second stage (240) and to compensate for vibration of the first stage (238).