Automated drywall sanding system and method

1. An automated drywalling system for sanding joint compound applied to drywall of a wall assembly, the automated drywalling system comprising:

a base unit that includes:

a platform,

a cart configured to be disposed on and move on the ground, and

a lift disposed between the platform and cart, the lift configured to raise the platform up and down;

an elongated robotic arm that extends between a base end and a distal end, the robotic arm coupled to the base unit on the platform at the base end of the robotic arm;

a sanding end effector coupled at the distal end of the robotic arm, the sanding end effector including:

a sanding head configured for sanding a target surface,

an end effector linear actuator mechanism for tracking of surface contours of the target surface by the sanding head, applying constant normal force to the target surface by the sanding head, and compensating for errors in the positioning of the sanding head relative to the target surface via a stroke of the linear actuator mechanism, the end effector linear actuator mechanism including a sensor for monitoring the stroke of the end effector linear actuator mechanism; and

a guiding element configured to engage the target surface or adjacent portion of a wall assembly to guide the sanding end effector in sanding the target surface;

one or more vision systems;

one or more sensors;

a computing device executing a computational planner that:

obtains target surface data from the one or more vision systems and the one or more sensors, the target surface data including information regarding a configuration of a wall assembly including a plurality of drywall pieces disposed on the wall assembly forming one or more joints between respective drywall pieces and having joint compound applied to the one or more joints;

automatically generates instructions for driving the sanding end effector, robotic arm, and base unit to perform at least one sanding task that includes the sanding end effector at least sanding joint compound applied to the one or more joints, the generating based at least in part on the target surface data;

automatically drives the sanding end effector, robotic arm, and base unit to perform the at least one sanding task; and

automatically updates tool paths and tool parameters of the sanding end effector based at least in part on a feedback mechanism, including the sensor for monitoring the stroke of the end effector linear actuator mechanism, to provide for a desired contact being maintained between the sanding head and the target surface during the at least one sanding task.

2. The automated drywalling system of claim 1 , wherein the generating instructions for driving the sanding end effector, robotic arm, and base unit to sand joint compound of the one or more joints between the respective drywall pieces is further based on at least one of:

data obtained while the automated drywalling system was applying joint compound to the one or more joints between respective pieces of drywall; and

data obtained while the automated drywalling system was hanging the drywall pieces on the wall assembly.

3. The automated drywalling system of claim 1 , wherein the sanding end effector further comprises a vacuum hood disposed around at least a portion of the sanding head to capture sanding debris generated by the sanding head sanding joint compound of the one or more joints between the respective drywall pieces, the vacuum hood coupled to a vacuum line that extends via the robotic arm to a vacuum source disposed at the base unit, the vacuum source generating a vacuum at the vacuum hood via the vacuum line.

4. The automated drywalling system of claim 1 , wherein the sanding end effector further includes a powered active gimbal configured to set a tip-tilt angle of the sanding head, the powered active gimbal comprising:

a gimbal structure having a greater circumscribed diameter than a maximum diameter of the sanding head;

a first bar assembly coupled to the sanding head, the first bar assembly coupled to the gimbal ring via a plurality of first pivots;

a second bar assembly coupled to the gimbal ring via a plurality of second pivots;

a first set of spring-damper assemblies coupled between the first bar assembly and the gimbal structure; and

a second set of spring-damper assemblies coupled between the second bar assembly and the gimbal structure.

5. The automated drywalling system of claim 1 , wherein the sanding end effector further includes a force limiting stage assembly that comprises one or more pneumatic springs configured to allow the sanding head to move relative to the distal end of the robotic arm to limit force applied to the target surface.

6. An automated drywalling system comprising:

a base unit;

an elongated robotic arm that extends between a base end and a distal end, the robotic arm coupled to the base unit at the base end of the robotic arm;

a sanding end effector coupled at the distal end of the robotic arm, the sanding end effector configured to sand joint compound on a target surface and including an end effector actuator mechanism for at least one of tracking of surface contours of the target surface by the sanding end effector, applying a selected normal force to the target surface by the sanding head, and compensating for errors in the positioning of the sanding end effector relative to the target surface via a stroke of the actuator mechanism, the end effector actuator mechanism including a sensor for monitoring the stroke of the end effector actuator mechanism;

one or more vision systems; and

a computing device executing a computational planner that:

obtains target surface data from the one or more vision systems, the target surface data including information regarding a configuration of a wall assembly including a plurality of drywall pieces disposed on the wall assembly forming one or more joints between respective drywall pieces having joint compound applied thereon;

automatically generates instructions for driving the sanding end effector, robotic arm, and base unit to perform at least one sanding task that includes the sanding end effector at least sanding the applied joint compound associated with the one or more joints between the respective drywall pieces, the generating based at least in part on the target surface data;

automatically drives the end effector, robotic arm, and base unit to perform the at least one sanding task; and

automatically updates at least one of tool paths and tool parameters of the sanding end effector based at least in part on a feedback mechanism, including the sensor for monitoring the stroke of the end effector actuator mechanism, to provide for a desired contact being maintained between the sanding end effector and the target surface during the at least one sanding task.

7. The automated drywalling system of claim 6 , wherein the generating instructions for driving the sanding end effector, robotic arm, and base unit to sand joint compound of the one or more joints between the respective drywall pieces is further based on data obtained while the automated drywalling system was applying joint compound to the one or more joints between respective pieces of drywall.

8. The automated drywalling system of claim 6 , wherein the sanding end effector further comprises a vacuum hood disposed around at least a portion of the sanding head to capture sanding debris generated by the sanding head sanding joint compound of the one or more joints between the respective drywall pieces.

9. The automated drywalling system of claim 6 , wherein the sanding end effector further includes a gimbal that comprises:

a gimbal structure having a greater circumscribed diameter than a diameter of the sanding head;

a first bar assembly coupled to the sanding head, the first bar assembly coupled to the gimbal ring via a plurality of first pivots; and

a second bar assembly coupled to the gimbal ring via a plurality of second pivots.

10. The automated drywalling system of claim 9 , wherein the gimbal further comprises:

a first set of spring-damper assemblies coupled between the first bar assembly and the gimbal ring; and

a second set of spring-damper assemblies coupled between the second bar assembly and the gimbal ring.

11. The automated drywalling system of claim 9 , wherein the gimbal comprises a powered active gimbal configured to set a tip-tilt angle of the sanding head.

12. The automated drywalling system of claim 6 , wherein the sanding end effector further includes a force limiting stage assembly that comprises a one or more pneumatic springs configured to allow the sanding head to move relative to the distal end of the robotic arm to limit force applied to the target surface.

13. The automated drywalling system of claim 6 , wherein the sanding end effector further includes a guiding element configured to engage the target surface or adjacent portion of a wall assembly to guide the sanding end effector in sanding the target surface.

14. An automated sanding system comprising:

a positioning stage that extends between a base end and a distal end;

a sanding end effector coupled at the distal end of the positioning stage, the sanding end effector configured to sand a target surface and including an end effector actuator mechanism for at least one of tracking of surface contours of the target surface by the sanding end effector, applying a desired normal force to the target surface by the sanding head, and compensating for errors in the positioning of the sanding end effector relative to the target surface via a configuration of the actuator mechanism, the end effector actuator mechanism including a sensor for monitoring the configuration of the end effector actuator mechanism; and

a computing device executing a computational planner that:

generates instructions for driving the sanding end effector and positioning stage to perform at least one sanding task that at least includes the sanding end effector sanding a target surface, the generating based at least in part on obtained target surface data;

drives the end effector and robotic arm to perform the at least one sanding task; and

updates at least one of tool paths and tool parameters of the sanding end effector based at least in part on a feedback mechanism, including the sensor for monitoring the configuration of the end effector actuator mechanism, to provide for a desired contact being maintained between the sanding end effector and the target surface during the at least one sanding task.

15. The automated sanding system of claim 14 , wherein the positioning stage comprises a robotic arm.

16. The automated sanding system of claim 14 , wherein the sanding end effector further comprises a vacuum hood disposed around at least a portion of the sanding head to capture sanding debris generated by the sanding of the target surface.

17. The automated sanding system of claim 14 , wherein the sanding end effector further includes a gimbal that comprises:

a gimbal structure;

a first bar assembly coupled to the sanding head, the first bar assembly coupled to the gimbal ring via one or more first pivots; and

a second bar assembly coupled to the gimbal ring via one or more second pivots.

18. The automated sanding system of claim 14 , wherein the sanding end effector further includes a force limiting stage assembly that comprises one or more pneumatic springs configured to allow the sanding head to move relative to the distal end of the robotic arm to limit force applied to the target surface.

19. The automated sanding system of claim 18 , wherein the force limiting stage assembly comprises a plurality of linear guides that constrain the sanding head rotating relative to a mounting flange opposing the sanding head.

20. The automated drywalling system of claim 14 , wherein the sanding end effector further includes a guiding element configured to engage the target surface to guide the sanding end effector in sanding the target surface.