Abstract: In bonding a number of pads which may have different heights within a predetermined tolerance the bonding tool (28, 24, 14, 10) is moved in slow speed search mode (70) to contact the first pad (P.sub.1) and store the height (H.sub.1) of the first pad (P.sub.1). After a predetermined amount of continued overtravel (OT.sub.1) the bond is performed and the tool raised. Operations on other pads may occur at this point. The tool is then moved to a point above the location of the second pad. The tool is moved down to the second pad without a search mode but to a second pad target height (H.sub.1 +OT.sub.2) that is the sum of the sensed height of the preceding pad and an overtravel distance.

Abstract: A spray coating booth for enclosing individual articles to be coated with a liquid spray while the articles are supported in closely spaced relation on an article conveyor for movement through the booth includes a rigid frame with fixed sidewalls and movable top and end walls which may be moved between a closed position completely enclosing an article supported on the conveyor and an open position to permit articles to be moved into and out of the booth. The movable top assures against coating liquid dripping onto and contaminating articles moving on the conveyor which are not to be coated. The end walls are supported for movement in substantially a transverse vertical plane to permit close spacing of articles on the conveyor without contact of the articles by the end walls.

Abstract: An edge trimmer for trimming the side edges of a running length of metal strip having upper and lower rotary shearing cutter discs engaging the top and bottom respectively, of the strip being trimmer includes top and bottom cylindrical strip stabilizers mounted coaxially with the cutter discs engaging the top and bottom surface of the strip adjacent the trim line, and a movable holddown roll disposed inboard of the top strip stabilizer and cooperating with the lower strip stabilizer to stabilize the strip at a location spaced inward from the trim line. The holddown roll is movable between an operable position engaging the strip and an inoperable position permitting access to the cutter disc for servicing.

Abstract: A system bus (13) carrying multidimensional path data interfaces with a plurality of local microprocessors (24), one for each dimension, through a plurality of dual access memory structures (21), one for each local microprocessor (24). A local arbiter (35) controls access to each dual access memory structure (21), facilitating elimination of wait states in data transfers between the bus (13) and memory (21) and between the local microprocessor (24) and memory (21). The arbiter (35) is implemented using a programmable logic device state machine approach, which implements a mode of operation wherein the circuitry is armed for a transfer between a local microprocessor (24) and the dual access memory (21) and accomplishes such transfer with no wait states.

Abstract: A digital robotic axis controller which employs a digital processor to apply the inverse of a plant model transfer function to positional information representative of a target path to generate a feed forward position control signal and to combine an error signal with the positional information to generate a feedback control signal. The feed forward and feedback control signals are combined to produce a total position control signal which is supplied to a digital-to-analog converter and then to a plant comprising an amplifier, a motor for establishing the actual position of a robotic member, and an encoder for deriving the error signal from the motor position. In application, a number of such plants are controlled to achieve a coordinated multidimensional movement with increased accuracy.

Abstract: A digital servo system for causing a mechanical element (48) to track a desired path and hold various positions along the path and employing a lead/lag integrator (18) in parallel with a feedback control loop. The input to the integrator (18) is switched between velocity (V.sub.EK) error during pathtracking and position error (E.sub.K) during holding to increase the resistance of the mechanical element (48) to position changes caused by outside forces during both pathtracking and holding. The integrator function employed uses a term (U.sub.integrator(k-1)) representing a previous integrator output value to assist in smoothing perturbations caused by switching between position and velocity error.

Abstract: Louvered roof apparatus is disclosed which includes a plurality of overhanging louvers to provide shade as an integral part of a roof.