A technique for the detection of robot joint gear tightness

Abstract

Abstract A new technique for the examination of gear tightness in robot joint drive systems is presented. A single robot joint is subjected to random excitation while the rest of the joints are constrained. The corresponding link motion is monitored by two accelerometers mounted on the link. The transfer function of the translational component of link acceleration is then obtained. From the half peak magnitude bandwidth of the first resonant frequency it is possible to determine whether the joint gears under testing have a tight or loose meshing. Tests were performed on the wrist rotation joint of an industrial robot in two steady state positions with the end effector loaded and unloaded.