Force overshoot and other pressure disturbance mitigation in pneumatic force control devices
AssigneeATI Industrial Automation, Inc.
InventorsAndrew Glusiec, Samuel Koenke
Life of this patent
Estimating the term…
Abstract
Pressure disturbances in a pneumatic robotic force control device—including force overshoot upon initial contact between a robotic tool and a workpiece—are mitigated by increasing the mass air flow in or out of a pneumatic chamber via one or more force overshoot mitigation air passages formed in the robotic force control device. The force overshoot mitigation air passages may connect the two chambers in air flow relationship, or may allow air flow from a chamber to the exterior. The force overshoot mitigation air passages may have a static or variable effective area. The optimal area may be calculated based on measured flow rates and pressures during typical use cases.
Claims16
A robotic force control device configured to be interposed between a robot arm and a robotic tool, comprising:
- a carriage capable of linear motion along an axis and configured to be directly connected to the robotic tool;
- a pneumatic cylinder containing a piston dividing the cylinder into first and second chambers;
- a rod connected to the piston and protruding from the cylinder, the rod directly connected to the carriage outside of the cylinder;
- a pneumatic control system connected in an air flow relation with at least one of the first and second cylinder chambers via corresponding first and second air lines;
- and
- at least one force overshoot mitigation air passage configured to increase a mass air flow rate to or from at least one of the chambers and thereby reduce an effect of pressure disturbances in the piston chambers upon movement of the carriage, so as to minimize a force overshoot between the robotic tool and the object, upon initial contact between the robotic tool and the object.
A method of operating a robotic force control device interposed between a robot arm and a robotic tool, the device comprising a carriage capable of linear motion along an axis and configured to be directly connected to a robotic tool, a pneumatic cylinder containing a piston dividing the cylinder into first and second chambers, a rod connected to the piston and protruding from the cylinder, the rod directly connected to the carriage outside of the cylinder, and a pneumatic control system connected in air flow relation with each of the first and second cylinder chambers via respective first and second air lines, the method comprising:
- increasing a mass air flow rate to or from at least one of the chambers via at least one force overshoot mitigation air passage, and thereby reducing the effect of pressure disturbances in the piston chambers upon movement of the carriage;
- and
- moving the robot arm such that the robotic tool contacts the workpiece, whereby the carriage moves relative to the pneumatic cylinder;
- whereby the force overshoot mitigation air passage minimizes a force overshoot between the robotic tool and the workpiece, upon initial contact between the robotic tool and the workpiece.
Dependencies are inferred from the claim text.