Supplementary metrology position coordinates determination system including an alignment sensor for use with a robot

A method for operating a supplementary metrology position coordinates determination system that is utilized with a robot,

• the robot comprising:
• a movable arm configuration, wherein the movable arm configuration comprises an end tool mounting configuration that is located proximate to a distal end of the movable arm configuration, and the robot is configured to move the movable arm configuration so as to move at least a portion of an end tool that is mounted to the end tool mounting configuration along at least two dimensions in an end tool working volume;
• and
• a motion control system configured to control an end tool position or a measuring point position of the end tool with a level of accuracy defined as a robot accuracy, based at least in part on sensing and controlling the position of the movable arm configuration using at least one position sensor included in the robot;
• the supplementary metrology position coordinates determination system comprising:
• a first imaging configuration comprising a first camera, the first imaging configuration having an optical axis;
• an XY scale comprising a nominally planar substrate and a plurality of respective imagable features distributed on the substrate, wherein the respective imagable features are located at respective known XY scale coordinates on the XY scale and a scale plane is defined to nominally coincide with the planar substrate of the XY scale, and a direction normal to the scale plane is defined as a scale imaging axis direction;
• an operational alignment subsystem OAS comprising at least an alignment sensor ASen and an operational alignment actuator configuration, wherein the alignment sensor is located proximate to the first camera and is mounted in a rigid configuration relative to the first camera, and the alignment sensor is configured to provide an alignment signal indicative of the scale imaging axis direction;
• an image triggering portion;
• and
• a metrology position coordinate processing portion,
• wherein:
• the supplementary metrology position coordinates determination system is configured with a movable one of the XY scale or the first imaging configuration coupled to the operational alignment actuator configuration which is coupled to, or part of the movable arm configuration and the other one of the XY scale or the first imaging configuration coupled to a stationary element proximate to the robot, with the stationary one of the XY scale or the first imaging configuration defining a first reference position;
• the robot system is configured to operate the operational alignment subsystem and the operational alignment actuator configuration to adjust an alignment of the moveable one of the XY scale or the first imaging configuration based on the alignment signal provided by the alignment sensor to provide an operational configuration of the supplementary metrology position coordinates determination system, wherein in the operational configuration of the supplementary metrology position coordinates determination system the XY scale and the first imaging configuration are arranged with the optical axis of the first imaging configuration parallel to the direction of the scale imaging axis direction as indicated by the alignment signal, and with the scale plane located within the range of focus of the first imaging configuration along the scale imaging axis direction;
• the method comprising:
• operating the operational alignment subsystem and the operational alignment actuator configuration to provide the operational configuration of the supplementary metrology position coordinates determination system the optical axis of the first imaging configuration parallel to the direction of the scale imaging axis direction as indicated by the alignment signal, and with the scale plane located within the range of focus of the first imaging configuration along the scale imaging axis direction;
• receiving at the image triggering portion at least one input signal that is related to the end tool position or a measuring point position of the end tool and determining the timing of a first imaging trigger signal based on the at least one input signal and outputting the first imaging trigger signal to the first imaging configuration, wherein the first imaging configuration acquires a digital image of the XY scale at an image acquisition time in response to receiving the first imaging trigger signal, and for which the supplementary metrology position coordinates determination system is at least nominally in the operational configuration when the digital image is acquired;
• receiving at the metrology position coordinate processing portion the acquired image and identifying at least one respective imagable feature included in the acquired image of the XY scale, and the related respective known XY scale coordinate location;
• and
• determining metrology position coordinates that are indicative of a relative position between the movable one of the XY scale or the first imaging configuration and the first reference position, based on determining an image position of the identified at least one respective imagable feature in the acquired image, wherein the determined metrology position coordinates are indicative of the end tool position or a measuring point position of the end tool at the image acquisition time, with an accuracy level that is better than the robot accuracy, at least for a vector component of the metrology position coordinates that is at least one of transverse or perpendicular to the scale imaging axis direction.

A supplementary metrology position coordinates determination system for use with a robot system comprising:

• a movable arm configuration, wherein the movable arm configuration comprises an end tool mounting configuration that is located proximate to a distal end of the movable arm configuration, and the robot is configured to move the movable arm configuration so as to move at least a portion of an end tool that is mounted to the end tool mounting configuration along at least two dimensions in an end tool working volume;
• and
• a motion control system configured to control an end tool position or a measuring point position of the end tool with a level of accuracy defined as a robot accuracy, based at least in part on sensing and controlling the position of the movable arm configuration using at least one position sensor included in the robot;
• the supplementary metrology position coordinates determination system, comprising:
• a first imaging configuration comprising a first camera, the first imaging configuration having an optical axis;
• an XY scale comprising a nominally planar substrate and a plurality of respective imagable features distributed on the substrate, wherein the respective imagable features are located at respective known XY scale coordinates on the XY scale and a scale plane is defined to nominally coincide with the planar substrate of the XY scale, and a direction normal to the scale plane is defined as a scale imaging axis direction;
• an operational alignment subsystem comprising at least an alignment sensor and an operational alignment actuator configuration, wherein the alignment sensor is located proximate to the first camera and is mounted in a rigid configuration relative to the first camera, and the alignment sensor is configured to provide an alignment signal indicative of the scale imaging axis direction;
• an image triggering portion configured to input at least one input signal that is related to the end tool position or a measuring point position of the end tool and determine the timing of a first imaging trigger signal based on the at least one input signal and output the first imaging trigger signal to the first imaging configuration, wherein the first imaging configuration is configured to acquire a digital image of the XY scale at an image acquisition time in response to receiving the first imaging trigger signal, and
• a metrology position coordinate processing portion configured to input the acquired image and identify at least one respective imagable feature included in the acquired image of the XY scale, and the related respective known XY scale coordinate location, and
• wherein the supplementary metrology position coordinates determination system is configured such that when it is operably connected to the robot system:
• the supplementary metrology position coordinates determination system is configured with a movable one of the XY scale or the first imaging configuration coupled to the operational alignment actuator configuration which is coupled to, or part of, the movable arm configuration, and the other one of the XY scale or the first imaging configuration coupled to a stationary element proximate to the robot, with the stationary one of the XY scale or the first imaging configuration defining a first reference position;
• the robot system is configured to operate the operational alignment subsystem and the operational alignment actuator configuration to adjust an alignment of the moveable one of the XY scale or the first imaging configuration based on the alignment signal provided by the alignment sensor to provide an operational configuration of the supplementary metrology position coordinates determination system, wherein in the operational configuration of the supplementary metrology position coordinates determination system the XY scale and the first imaging configuration are arranged with the optical axis of the first imaging configuration parallel to the direction of the scale imaging axis direction as indicated by the alignment signal, and with the scale plane located within the range of focus of the first imaging configuration along the scale imaging axis direction;
• the supplementary metrology position coordinates determination system is configured such that when the moveable one of the XY scale or the first imaging configuration and the stationary one of the XY scale or the first imaging configuration are arranged in the operational configuration, and the movable arm configuration is positioned with the XY scale in a field of view of the first imaging configuration, then the metrology position coordinate processing portion is operable to determine metrology position coordinates that indicate a relative position between the movable one of the XY scale or the first imaging configuration and the first reference position with an accuracy level that is better than the robot accuracy, based on determining an image position of the identified at least one respective imagable feature in the acquired image;
• and
• the determined metrology position coordinates are indicative of the end tool position or a measuring point position of the end tool at the image acquisition time, with an accuracy level that is better than the robot accuracy, at least for a vector component of the metrology position coordinates that is at least one of transverse or perpendicular to the scale imaging axis direction.

A robot system, comprising:

• a robot, comprising:
• a movable arm configuration, wherein the movable arm configuration comprises an end tool mounting configuration that is located proximate to a distal end of the movable arm configuration, and the robot is configured to move the movable arm configuration so as to move at least a portion of an end tool that is mounted to the end tool mounting configuration along at least two dimensions in an end tool working volume;
• and
• a motion control system configured to control an end tool position or a measuring point position of the end tool with a level of accuracy defined as a robot accuracy, based at least in part on sensing and controlling the position of the movable arm configuration using at least one position sensor included in the robot;
• and
• wherein:
• the robot system further comprises a supplementary metrology position coordinates determination system, comprising:
• a first imaging configuration comprising a first camera, the first imaging configuration having an optical axis;
• an XY scale comprising a nominally planar substrate and a plurality of respective imagable features distributed on the substrate, wherein the respective imagable features are located at respective known XY scale coordinates on the XY scale and a scale plane is defined to nominally coincide with the planar substrate of the XY scale, and a direction normal to the scale plane is defined as a scale imaging axis direction;
• an operational alignment subsystem OAS comprising at least an alignment sensor, wherein the alignment sensor is located proximate to the first camera and is mounted in a rigid configuration relative to the first camera, and the alignment sensor is configured to provide an alignment signal Asig indicative of the scale imaging axis direction;
• an image triggering portion configured to input at least one input signal that is related to the end tool position or a measuring point position of the end tool and determine the timing of a first imaging trigger signal based on the at least one input signal and output the first imaging trigger signal to the first imaging configuration, wherein the first imaging configuration is configured to acquire a digital image of the XY scale at an image acquisition time in response to receiving the first imaging trigger signal, and
• a metrology position coordinate processing portion configured to input the acquired image and identify at least one respective imagable feature included in the acquired image of the XY scale, and the related respective known XY scale coordinate location, and
• wherein:
• the supplementary metrology position coordinates determination system is configured with a movable one of the XY scale or the first imaging configuration coupled to the movable arm configuration, and the other one of the XY scale or the first imaging configuration coupled to a stationary element proximate to the robot, with the stationary one of the XY scale or the first imaging configuration defining a first reference position;
• the robot system is configured to provide at least a nominal operational configuration of the supplementary metrology position coordinates determination system, wherein in the nominal operational configuration of the supplementary metrology position coordinates determination system the XY scale and the first imaging configuration are arranged with the optical axis of the first imaging configuration nominally parallel to the direction of the scale imaging axis direction and with the scale plane located within the range of focus of the first imaging configuration along the scale imaging axis direction;
• the robot system is configured to operate the operational alignment subsystem to determine a residual misalignment between the optical axis and the scale imaging axis as indicated by the alignment signal provided by the alignment sensor;
• the supplementary metrology position coordinates determination system is configured such that when the moveable one of the XY scale or the first imaging configuration and the stationary one of the XY scale or the first imaging configuration are arranged in the nominal operational configuration, and the movable arm configuration is positioned with the XY scale in a field of view of the first imaging configuration, then the metrology position coordinate processing portion is operable to acquire the digital image of the XY scale at an image acquisition time, and determine a corresponding residual misalignment, and determine a first set of metrology position coordinates that indicate a relative position between the movable one of the XY scale or the first imaging configuration and the first reference position with an accuracy level that is better than the robot accuracy at least for a vector component of the first set of metrology position coordinates that is at least one of transverse or perpendicular to the scale imaging axis direction, based on an image position of the identified at least one respective imagable feature in the acquired image and the corresponding residual misalignment.