Abstract: A method for soldering a lead to a pad having a solder plate formed thereon is described. In one embodiment of the method, a tape is disposed between the lead and a laser source, and the method includes the steps of aligning the lead with the solder plated pad, transmitting a beam from the laser source through the tape and to a location where a solder joint is to be formed, and the beam heating the solder plate thereby causing reflow of the solder plate to form a solder joint.

Abstract: An input/output port for a lasing medium to minimize wavefront distortion of a coherent light beam is described. The input/output port includes an end surface integral the medium and a first port surface integral the end surface. The first port surface is substantially perpendicular to a plane normal to the longitudinal axis extending through the medium so that each ray of a beam of coherent electromagnetic radiation lying in a plane of a thickness of the beam may impinge on the port surface at a substantially equal angle with respect to reference planes normal to the port surface at the points of impingement.

Abstract: The weldability of a part formed from an alloy having low impurity concentrations is determined by initiating an arc between a stationary welding torch and the part using a predetermined set of welding parameters selected to produce a partially penetrating molten weld pool. The natural frequency of oscillation of the molten weld pool is measured a predetermined time following initiation of the arc, and the measured natural frequency of oscillation is compared to empirically determined data for the alloy to determine the weldability of the particular part. Variations in trace element concentrations between different heats of the same alloy affect the three-dimensional geometry of the molten weld pool, and in turn affect its resonant frequency. The invention may be used to adjust the welding parameters to accommodate differences in weldability between different heats of the same alloy.

Abstract: The penetration in an arc welding process is measured in real time by monitoring the natural frequency of oscillation of the weld pool. Spatial oscillations are induced in the weld pool by modulating either the shielding gas or the welding current at a plurality of different frequencies, and the light reflected from the pool at a non-specular angle is sensed and processed to determine the natural frequency of oscillation. Both pulse and swept frequency modulations are employed for excitation of the weld pool.

Abstract: A high response servodriven robotics tool carrier assembly is especially well adapted for carrying a tool, such as an arc welding torch. The robotics tool carrier assembly mounts the torch such that its tip is on the center line of the arm rotation axis of a robot welding machine. The robotics tool carrier assembly modulates the coarse robot movements which are programmed into the robot arm. A tilt linkage is used to tilt the torch about its tip so as to avoid obstructions. The tilt linkage is mounted upon a Z slide which adjusts the distance between the tip of the torch and a work surface. The Z slide is in turn mounted upon an X member movably mounted to an arm support so as to modulate the torch in a cross seam direction. The robotics tool carrier assembly mounts upon a robotics arm.

Abstract: The positioning system of an industrial robot having a vision sensor and structured light pattern projector, such as a welding robot, is centered and vectored along a joint to be tracked. Navigation information derived from the scene is used to compute move microvectors; the next move vector is extracted and computed while the current move vector is executed. To track 90.degree. corners and small radius turns, the parallelism between two lines formed by the intersection of concentric circular arc light stripes and the joint edges is determined. When the parallelism is out of limits the previously calculated microvector is used until parallelism is re-established.

Abstract: An industrial robot is controlled to move by increments and approximately track an edge or a joint. A structured light pattern such as two parallel light bars is projected onto the workpiece and the scene is imaged by a visual sensor. Information derived from the image is used to compute move vectors. The navigation algorithm is based on extracting and computing the next move vector from the visual scene while the current move vector is being executed. The positioning system of an arc welding robot approximately follows the joint to be welded; the computed microvectors specify the direction and distance the positioning system moves.

Abstract: A gas metal arc welding torch has an integral optical system which images the weld puddle on the face of a fiber optic cable. A concentric torch configuration is disclosed having a slim profile filler wire guide that is removably mounted on the ring-shaped torch body and projects into the gas cup at an angle to the optical axis to minimize obstruction of important regions of the weld scene. The fiber optic cable is coupled to a video camera and a viewing system or controller; real time observation of the weld area is made and used to control the weld process.

Abstract: A gas tungsten arc welding torch has an integral optical system which images the weld puddle on the face of a fiber optic cable, and is suitable for industrial welding. The copper torch body has cover gas, electrical power, and coolant connections and an integral slim profile electrode holder. The optical lens is located directly above the electrode; the holder is out of focus and is not seen in the image of the weld region. A concentric torch configuration is more compact and has a large field of view at the weld area. When coupled to a remote video camera and monitor components, the torch-vision system permits control of torch manipulation and of the weld process.

Abstract: A tactile area sensor for robots has an array of pneumatic flow passages. The air flow in each passage is dependent on a localized force exerted by an object pressing against an elastic pad on the face of the sensor. The air flow impinges on a metallic tab and its angular displacement is sensed by directing a light beam from an optical fiber onto the tab and monitoring the quantity of light reflected to a paired optical fiber. The array of optical outputs can be presented to a charge injection device and are dependent on the shape of the object.