Patent ID: 8360997
Filing Date: 2013-01-29
Classification: A61H,A63B,B25J,Y10T

Abstract:
1. A robot arm, comprising: at least one pivoted lever, the at least one pivoted lever comprising a support, a base, a pivotable piece, and a plurality of pneumatic muscles, the base being rigidly connected to a first end of the support, the pivotable piece being mounted on a second end of the support pivotably about one or two axes aligned divergent from the longitudinal direction of the support, wherein the pneumatic muscles extend from the base to the pivotable piece, individual pneumatic muscles engaging the pivotable piece at opposite sides of pivot axes of the pivotable piece; and a controller that measures a position of the at least one pivoted lever and a pressure applied to the individual pneumatic muscles, and calculates an externally acting force using pressure-displacement diagrams of the individual pneumatic muscles and geometric lever ratios for all pivoted levers provided with pneumatic muscles, and limits the externally acting force over time during a plurality of monitored passes of the robot arm through a movement range using profiles prepared for the plurality of monitored passes, wherein during a first monitored pass, the controller prepares a first profile of a first actual path of the at least one pivoted lever as affected by the externally acting force, wherein the controller establishes a reaction force in at least one of the plurality of pneumatic muscles that counteracts a deviation between the first actual path of the at least one pivoted lever and a pre-programmed setpoint path of the at least one pivoted lever, wherein the reaction force is applied during at least one second monitored pass after the first monitored pass, wherein, during the at least one second monitored pass, the controller prepares a second profile of a second actual path of the at least one pivoted lever as affected by the externally acting force and the reaction force, wherein the reaction force established for an subsequent monitored pass after the first monitored pass is dependent upon an amount of the deviation during a receding monitored pass.