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:
A stage assembly (220) for moving a device (200) includes a stage (208), an attraction-only type actuator pair (426) that moves the stage (208), and a control system (24). In one embodiment, the actuator pair (426) includes a first electromagnet (436F), a first conductor (438F) and a first target (440F) having a first target surface (442F). The actuator pair also includes a second electromagnet (436S), a second conductor (438S) and a second target (440S) having a second target surface (442S). The first electromagnet (436F) is positioned at a first angle θ1 relative to a first target surface (442F) and the second electromagnet (436S) is positioned at a second angle θ2 relative to the second target surface (442S). The control system (24) directs a first current to one or more of the electromagnets based on at least one of the angles θ1, θ2. Further, one or more electromagnets (436) can include a first measurement point and a second measurement point. The control system (24) can direct current to the actuator pair (426) based on the relative distance between the first and second measurement points and the corresponding target surface (442).
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:
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 stage assembly (220) for moving a device (200) includes a stage (208), an attraction-only type actuator pair (426) that moves the stage (208), and a control system (24). In one embodiment, the actuator pair (426) includes a first electromagnet (436F), a first conductor (438F) and a first target (440F) having a first target surface (442F). The actuator pair also includes a second electromagnet (436S), a second conductor (438S) and a second target (440S) having a second target surface (442S). The first electromagnet (436F) is positioned at a first angle θ1 relative to a first target surface (442F) and the second electromagnet (436S) is positioned at a second angle θ2 relative to the second target surface (442S). The control system (24) directs a first current to one or more of the electromagnets based on at least one of the angles θ1, θ2. Further, one or more electromagnets (436) can include a first measurement point and a second measurement point. The control system (24) can direct current to the actuator pair (426) based on the relative distance between the first and second measurement points and the corresponding target surface (442).