Abstract: A method of controlling a robot (32) includes the steps of selecting an initial configuration from at least one of a first, second, and third sets to position a TCP at a starting point (44) along a path (33) and selecting a final configuration different than the initial configuration to position the TCP at an ending point (46). Next, the TCP moves from the starting point (44) while maintaining the initial configuration, approaches the singularity between a first point (48) and a second point (50), and selects one of the axes in response to reaching the first point (48). The angle for the selected axis is interpolated from the first point (48) to the second point (50). After the interpolation, the angles about the remaining axes are determined and positions the arms in the final configuration when the TCP reaches the second point (50) and moves to the ending point (46) while maintaining the final configuration.

Abstract: An intelligent power assisted manual manipulator controllable by operator inputs from an operator for moving an object is provided. The manipulator includes a movable base supporting a lift mechanism for moving the object. The manipulator also includes at least one servomotor for actuating at least one of the movable base and the lift mechanism for moving the object. An operator control mechanism for receiving the operator inputs is supported on the lift mechanism. A plurality of force sensors are disposed between the operator control mechanism and the lift mechanism for sensing said operator inputs and actuating at least one of the at least one servomotor. The movable base includes an overhead rail defining a generally horizontal first axis and a carriage supported on the overhead rail and movable along the first axis. The lift mechanism includes a turret assembly supported on the carriage having a generally vertical second axis, and a generally horizontal third axis.

Abstract: A robot calibration system for calibrating a robot and a method of determining a position of the robot to calibrate the robot are disclosed. The system includes an electrical ground defining a return for an electrical circuit. The robot, which is electrically connected to the ground, includes an arm having a tool surface operating within a robot workspace. The system also includes an electrical supply and a detection device. The electrical supply defines a source for the circuit and provides a charge and a reference voltage to the system. The detection device communicates with the electrical supply to detect variations in either the charge, the reference voltage, or both. The system further includes a calibration object. The calibration object is electrically insulated from the ground and is electrically connected to the electrical supply.

Abstract: A robot calibration system for calibrating a robot and a method of determining a position of the robot to calibrate the robot are disclosed. The system includes an electrical ground defining a return for an electrical circuit. The robot, which is electrically connected to the ground, includes an arm having a tool surface operating within a robot workspace. The system also includes an electrical supply and a detection device. The electrical supply defines a source for the circuit and provides a charge and a reference voltage to the system. The detection device communicates with the electrical supply to detect variations in either the charge, the reference voltage, or both. The system further includes a calibration object. The calibration object is electrically insulated from the ground and is electrically connected to the electrical supply.

Abstract: A method of teaching a robot a desired operating path and a lead-through teach handle assembly are disclosed. A mounting mechanism mounts the entire handle assembly to an arm of the robot. The handle assembly also includes a handle that is supported by the mounting mechanism. A robot operator utilizes the handle assembly and grasps the handle to apply an external force to move the robot arm, or the operator, without the handle assembly, directly holds a tool connected to the robot arm to apply the external force at the tool. The handle assembly is characterized by a universal joint that interconnects the handle and the mounting mechanism and that accommodates orientation changes of the handle relative to the mounting mechanism that result from translational and rotational movement of the robot arm as the user is teaching the robot. The external force applied at the tool is estimated with either a force sensor disposed on the handle assembly or by monitoring the torque of motors used to move the robot.

Abstract: A method of determining contact positions of a robot relative to a workpiece in a workspace of the robot. The method utilizes the contact positions to determine a location of the workpiece in the robot workspace. The method also monitors an integral operating parameter within the robot, such as motor torque, to determine the contact positions of the robot relative to the workpiece and to locate the workpiece.

Abstract: A method of controlling a powered manipulator in a plurality of workspaces is disclosed. The manipulator includes a handle, a motor, a force sensor, and is in combination with a processor controlling the manipulator. The method includes the steps of imparting force on the control handle, sensing direction and magnitude of the force, and sending data of the force to the processor. The data is processed to establish movement commands for the manipulator. The processor is programmed to establish at least one virtual constraint in a first workspace for limiting movement of the manipulator to prevent an operator from moving the manipulator to a limit of this workspace. After the manipulator is moved in this workspace, the manipulator is relocated from the first workspace into a second workspace different from the first workspace where the manipulator is then moved again.

Abstract: A method for teaching movements to a robot (12) is disclosed. The robot (12) includes a fixture (14) for cooperating with a workpiece (16), at least one sensor (18) for sensing a spatial relationship of the robot fixture (14) relative to the workpiece (16), at least one motor (20), and a microprocessor (22) for controlling motion of the robot (12) relative to the workpiece (16).

Abstract: A method of controlling a powered manipulator in a plurality of workspaces is disclosed. The manipulator includes a handle, a motor, a force sensor, and is in combination with a processor controlling the manipulator. The method includes the steps of imparting force on the control handle, sensing direction and magnitude of the force, and sending data of the force to the processor, The data is processed to establish movement commands for the manipulator. The processor is programmed to establish at least one virtual constraint in a first workspace for limiting movement of the manipulator to prevent an operator from moving the manipulator to a limit of this workspace. After the manipulator is moved in this workspace, the manipulator is relocated from the first workspace into a second workspace different from the first workspace where the manipulator is then moved again.

Abstract: A robot calibration system includes a calibration sensor that provides an indication of when a first reference point that remains fixed relative to a robot base is a fixed distance from a second reference point that is located on the robot arm. The robot arm is moved through a plurality of orientations and each time that the fixed distance between the two reference points is achieved, robot joint position information is determined. The preferred calibration sensor includes a string that extends between the two reference points and activates a signal generator each time that the string is taut as caused by the orientation of the robot arm. The generated signal indicates that the two reference points are separated by the fixed distance. The determined robot joint positions are then used to determine a calibration factor which varies depending on the needs of a particular situation.

Abstract: A method of controlling movement of a robot includes moving only the wrist portion about two of the wrist axes to achieve a repeated and cyclical movement, such as a back-and-forth movement of the tool relative to a preselected path. Since only the wrist is moved, the range of available tool positions can be determined. In most instances, the desired position of the tool as it deviates from the path is outside of the range of available tool positions, given that only the wrist will move. The method of this invention includes determining a target position within the range of available positions that best corresponds to the desired position of the tool. A unique inverse kinematics solution, which includes fixing one of the wrist axes, is used to determine the wrist orientation required to place the tool into the target position.

Abstract: A method and system is disclosed for estimating a speed of a robot tool center point at a specified time. The method includes the step of receiving an input signal representing the specified time for which the speed estimate is desired. The method also includes the step of processing individual motion segment data to create a blended Cartesian velocity vector. The individual motion segment data represents at least one robot motion segment. The method finally includes the step of transmitting an output signal based on a scalar magnitude of the blended Cartesian velocity vector. The output signal represents the speed of the robot Tool Center Point at the specified time.

Abstract: A method and device of achieving motion cycle time reduction that takes motor capabilities, load inertia and gravity into account and, at the same time, produces acceptable tool tip vibration upon stopping. This cycle time reduction is especially applicable to short motions of a robot where the entire motion consists of acceleration and deceleration and there is no constant velocity region. The method and device provide open loop limiting factors for axis jerk, acceleration and velocity, taking into account robot position, payload and inertia.

Abstract: A method and system for automatically determining the position and orientation of an object by utilizing as few as a single digital image generated by as few as a single camera without the use of a structured light. The digital image contains at least three non-colinear geometric features of the object. The three features may be either coplanar or non-coplanar. The features or targets are viewed such that perspective information is present in the digital image. In a single camera system the geometric features are points, and in a multi-camera system, the features are typically combinations of points and lines. The location of the features are determined and processed within a programmed computer together with reference data and camera calibration data to provide at least three non-parallel 3-D lines. The 3-D lines are utilized by an iterative algorithm to obtain data relating to the position and orientation of the object in 3-D space.