Abstract: In a device having a first member and a second member which are driven relative to one another by an actuator, a servocontrol derives feedback by sensing the torque applied on one of the members by the actuator. The actuator drive signal is modified by a compensation network in response to the torque measurement to provide stability across a bandwidth extending beyond the resonant frequency of the members, thereby providing smooth, accurate and precise motion.

Abstract: A digitally controlled industrial robot comprises a set of unitized and integrated joint drive modules which can be assembled in series to form an arm. The joints are of two basic types, pitch joints and roll joints, with the roll joints providing rotation about the longitudinal axis of the manipulator and the pitch joints providing rotation about axes which are substantially perpendicular to and offset from the roll joint axes. Any number of joints may be assembled to comprise the manipulator, permitting the configuration of a kinematically redundant manipulator. A servocontrol derives feedback from sensing the motive force on a driven member and compensates the drive signal accordingly. More particularly, the torque exerted on each roll and pitch joint is measured and used for feedback to provide stability and optimum bandwidth for the servomechanism.

Abstract: A linkage mechanism, such as an industrial robot, comprises an electronic motion controller and a set of self-driven joints. A controller receives a series of end effector positions from memory or from a host control system which define a routine for the mechanism to execute in relation to a predetermined reference frame such as cartesian coordinates. Angular values for the joints are computed in real time which follow the predetermined reference frame values in a manner which avoids the problems of singularities and which efficiently accommodates kinematic redundancy. A corresponding drive signal is generated for each joint.

Abstract: A digitally controlled industrial robot comprises a set of unitized and integrated joint drive modules which can be assembled in series to form an arm. The joints are of two basic types, pitch joints and roll joints, with the roll joints providing rotation about the longitudinal axis of the manipulator and the pitch joints providing rotation about axes which are substantially perpendicular to and offset from the roll joint axes. Any number of joints may be assembled to comprise the manipulator, permitting the configuration of a kinematically redundant manipulator. A servocontrol derives feedback from sensing the motive force on a driven member and compensates the drive signal accordingly. More particularly, the torque exerted on each roll and pitch joint is measured and used for feedback to provide stability and optimum bandwidth for the servomechanism.

Abstract: A controller retrieves from memory a series of discrete end effector positions consisting of location and orientation of the end effector. Joint angle values are computed in real time corresponding to intermediate points along the path in a manner which provides smooth end effector motion, avoids the problems of singularities and efficiently accommodates kinematic redundancy. In particular, end effector reorientation between successive goal points is smoothly accomplished by rotating the end effector about the eigenvector of the two successive end effector orientations.