Load compensation for robotic applications

A method to compensate for a combined load offset on a part positioner system that positions a part to be worked on by a robot comprising:

• loading said part onto a part holding assembly of said part positioner system to create a combined load, said part positioner system having a rotational drive that rotates said combined load around a rotational drive axis of rotation and at least one column having at least one counter weight pack that extends substantially perpendicular to said rotational drive axis of rotation;
• holding said combined load using said rotational shoulder drive at an angular position such that said angular position of said combined load provides a substantive weight for said shoulder drive to resist when holding said combined load at said angular position;
• moving said at least one counter weight pack linearly along a length of said at least one column in a predetermined direction at a predetermined speed;
• measuring a torque applied to said shoulder drive as a function of power delivered to said shoulder drive while moving said at least one counter weight pack;
• reversing direction of said movement of said at least one counter weight pack if said measured torque is increasing;
• stopping said movement of said at least one counter weight pack at a balanced location on said column when said torque reaches a minimum torque value;
• and,
• operating said part positioner system with a balanced combined total load to position said part to accommodate work operations of said robot.

A method to compensate for a combined load offset on a part positioner system that positions a part to be worked on by a robot comprising:

• providing said part positioner system that has a shoulder with a rotational shoulder drive that rotates a part holding assembly around a shoulder center line, said shoulder center line being a line along an axis of rotation of said rotational shoulder drive, said part holding assembly comprising a column disposed perpendicular to said shoulder center line;
• providing a counter weight system for said column that has a counter weight pack that is moveable back and forth along at least a portion of said column length of said column by a linear actuator;
• loading said part to be worked on by said robot onto said part holding assembly to create a combined load of said part holding assembly and said part;
• determining a counter weight balance movement direction that indicates a direction to move said counter weight pack along said portion of said column length to reduce a torque applied by said rotational shoulder drive to rotate said combined load;
• measuring a base torque on said rotational shoulder drive by performing a torque measurement sub-process, said torque measurement sub-process further comprising:
• driving said combined load using said rotational shoulder drive;
• and,
• measuring a torque on said shoulder drive as a function of angular position of said rotational shoulder drive and power supplied to said rotational shoulder drive;
• performing a counter weight adjustment sub-process, said counter weight adjustment sub-process further comprising:
• moving said counter weight pack by said linear actuator said predetermined distance in said counter weight balance movement direction along said portion of said column length;
• measuring a test torque on said rotational shoulder drive by performing said torque measurement sub-process;
• comparing said base torque to said test torque;
• and,
• setting said base torque equal to said test torque and repeating said counter weight adjustment sub-process if said test torque is less than said base torque;
• and,
• operating said part positioner system with a balanced combined total load to position said part to accommodate work operations of said robot.

A load compensation system that compensates for a combined load offset on a part positioner system that positions a part to be worked on by a robot comprising:

• said part positioner system having a shoulder with a rotational shoulder drive that rotates a part holding assembly around a shoulder center line, said shoulder center line being a line along an axis of rotation of said rotational shoulder drive, said part holding assembly comprising a column having a column length disposed perpendicular to said shoulder center line;
• a counter weight system for said column that has a counter weight pack that is moveable back and forth along at least a portion of said column length of said column by a linear actuator;
• said part to be worked on by said robot being loaded onto said part positioner by being attached to said part holding assembly to create a combined load of said part holding assembly and said part;
• and,
• a torque measurement subsystem that drives said combined load using said rotational shoulder drive and measures torque on said rotational shoulder drive during said driving of said combined load as a function of angular position of said rotational shoulder drive and power supplied to said rotational shoulder drive;
• a counter weight adjustment subsystem that measures a test torque on said rotational shoulder drive using said torque measurement subsystem calculates an updated position for said counter weight pack that substantially balances said combined load with respect to said shoulder center line as a function of said test torque, and adjusts said counter weight pack by said linear actuator along said portion of said column length to said updated position.

A load compensation system that compensates for a combined load offset on a part positioner system that positions a part to be worked on by a robot comprising:

• said part positioner system having a part holding assembly with said part loaded on said part holding assembly to create a combined load, said part positioner system having a rotational drive that rotates said combined load around a rotational drive axis of rotation and at least one column having at least one counter weight pack that extends substantially perpendicular to said rotational drive axis of rotation;
• and,
• a load balancing subsystem that holds said combined load using said rotational shoulder drive at an angular position such that said angular position of said combined load provides a substantive weight for said shoulder drive to resist when holding said combined load at said angular position, moves said at least one counter weight pack linearly along a length of said at least one column in a predetermined direction at a predetermined speed, measures a torque applied to said shoulder drive as a function of power delivered to said shoulder drive while moving said at least one counter weight pack, reverses direction of said movement of said at least one counter weight pack if said measured torque is increasing, and stops said movement of said at least one counter weight pack at a balanced location on said column when said torque reaches a minimum torque value.

A load compensation system that compensates for a combined load offset on a part positioner system that positions a part to be worked on by a robot comprising:

• said part positioner system having a shoulder with a rotational shoulder drive that rotates a part holding assembly around a shoulder center line, said shoulder center line being a line along an axis of rotation of said rotational shoulder drive, said part holding assembly comprising a column having a column length disposed perpendicular to said shoulder center line;
• a counter weight system for said column that has a counter weight pack that is moveable back and forth along at least a portion of said column length of said column by a linear actuator;
• said part to be worked on by said robot being loaded onto said part positioner by being attached to said part holding assembly to create a combined load of said part holding assembly and said part;
• and,
• a movement direction determination subsystem that determines a counter weight balance movement direction that indicates a direction to move said counter weight pack along said portion of said column length to reduce a torque applied by said rotational shoulder drive to rotate said combined load;
• a torque measurement subsystem that drives said combined load using said rotational shoulder drive and measures torque on said rotational shoulder drive during said driving of said combined load as a function of angular position of said rotational shoulder drive and power supplied to said rotational shoulder drive;
• a base torque measurement subsystem that measures a base torque using said torque measurement subsystem;
• and,
• a counter weight adjustment subsystem that performs a counter weight adjustment process that moves said counter weight pack by said linear actuator said predetermined distance in said counter weight balance movement direction along said portion of said column length, measures said test torque on said rotational shoulder drive using said torque measurement subsystem;
• compares said base torque to said test torque, and, sets said base torque equal to said test torque and repeats said counter weight adjustment process if said test torque is less than said base torque.

A load compensation system that compensates for a combined load offset on a part positioner system that positions a part to be worked on by a robot comprising:

• means for providing said part positioner system that has a shoulder with a rotational shoulder drive that rotates a part holding assembly around a shoulder center line, said shoulder center line being a line along an axis of rotation of said rotational shoulder drive, said part holding assembly comprising a column having a column length disposed perpendicular to said shoulder center line;
• means for providing a counter weight system for said column that has a counter weight pack that is moveable back and forth along at least a portion of said column length of said column by a linear actuator;
• means for loading said part to be worked on by said robot onto said part positioner to create a combined load of said part holding assembly and said part;
• means for driving said combined load using said rotational shoulder drive;
• means for measuring a test torque on said rotational shoulder drive during said driving of said combined load;
• means for calculating an updated position for said counter weight pack that substantially balances said combined load with respect to said shoulder center line as a function of said test torque;
• means for adjusting said counter weight pack by said linear actuator along said portion of said column length to said updated position;
• and,
• means for operating said part positioner system with a balanced combined total load to position said part to accommodate work operations of said robot.

A load compensation system that compensates for a combined load offset on a part positioner system that positions a part to be worked on by a robot comprising:

• means for loading said part onto a part holding assembly of said part positioner system to create a combined load, said part positioner system having a rotational drive that rotates said combined load around a rotational drive axis of rotation and at least one column having at least one counter weight pack that extends substantially perpendicular to said rotational drive axis of rotation;
• means for holding said combined load using said rotational shoulder drive at an angular position such that said angular position of said combined load provides a substantive weight for said shoulder drive to resist when holding said combined load at said angular position;
• means for moving said at least one counter weight pack linearly along a length of said at least one column in a predetermined direction at a predetermined speed;
• means for measuring a torque applied to said shoulder drive as a function of power delivered to said shoulder drive while moving said at least one counter weight pack;
• means for reversing direction of said movement of said at least one counter weight pack if said measured torque is increasing;
• means for stopping said movement of said at least one counter weight pack at a balanced location on said column when said torque reaches a minimum torque value;
• and,
• means for operating said part positioner system with a balanced combined total load to position said part to accommodate work operations of said robot.

A load compensation system that compensates for a combined load offset on a part positioner system that positions a part to be worked on by a robot comprising:

• means for providing said part positioner system that has a shoulder with a rotational shoulder drive that rotates a part holding assembly around a shoulder center line, said shoulder center line being a line along an axis of rotation of said rotational shoulder drive, said part holding assembly comprising a column disposed perpendicular to said shoulder center line;
• means for providing a counter weight system for said column that has a counter weight pack that is moveable back and forth along at least a portion of said column length of said column by a linear actuator;
• means for loading said part to be worked on by said robot onto said part positioner to create a combined load of said part holding assembly and said part;
• means for determining a counter weight balance movement direction that indicates a direction to move said counter weight pack along said portion of said column length to reduce a torque applied by said rotational shoulder drive to rotate said combined load;
• means for measuring a base torque on said rotational shoulder drive by performing a torque measurement sub-process, said torque measurement sub-process further comprising:
• means for driving said combined load using said rotational shoulder drive;
• and,
• means for measuring a torque on said shoulder drive;
• means for performing a counter weight adjustment sub-process, said counter weight adjustment sub-process further comprising:
• means for moving said counter weight pack by said linear actuator said predetermined distance in said counter weight balance movement direction along said portion of said column length;
• means for measuring a test torque on said rotational shoulder drive by performing said torque measurement sub-process;
• means for comparing said base torque to said test torque;
• and,
• means for setting said base torque equal to said test torque and repeating said counter weight adjustment sub-process if said test torque is less than said base torque;
• and,
• means for operating said part positioner system with a balanced combined total load to position said part to accommodate work operations of said robot.