Actuating apparatus, actuating system and method for actuating a working stage to move relative to a platform with high-precision positioning capability

An actuating system comprising:

• a platform having a reference region that has speckle features and that is associated with a coordinate system;
• and
• an actuating apparatus including
• a motion driving module rigidly coupled to said platform,
• a working stage coupled to and driven by said motion driving module to move relative to said platform,
• a speckle image capturing module rigidly coupled to said working stage so as to be movable relative to said platform along with said working stage, and capable of capturing a speckle image of a sub-region of said reference region, and
• a control module operatively associated with said motion driving module and said speckle image capturing module, and operable in a positioning mode, where said control module obtains a current position of said working stage in the coordinate system based on a comparison between the speckle image captured by said speckle image capturing module and reference speckle image information that is associated with and unique to said reference region of said platform, and controls said motion driving module to drive said working stage toward a target position in the coordinate system based on a difference between the current position of said working stage and the target position.

A method for actuating a working stage to move relative to a platform, the working stage being coupled to and driven by a motion driving module which is rigidly coupled to the platform, the platform having a reference region that has speckle features and that is associated with a coordinate system, said method comprising the steps of:

• configuring a speckle image capturing module rigidly coupled to the working stage to capture a speckle image of a sub-region of the reference region;
• comparing the speckle image thus captured with reference speckle image information that is associated with and unique to the reference region of the platform;
• obtaining a current position of the working stage in the coordinate system based on a result of the comparison;
• and
• controlling the motion driving module to drive the working stage toward a target position in the coordinate system based on a difference between the current position of the working stage and the target position.