Abstract: A bidirectional lateral insulated gate bipolar transistor (IGBT) includes two gate electrodes. The IGBT can conduct current in two directions. The IGBT relies on a double RESURF structure to provide high voltage blocking in both directions. The IGBT is symmetrical, having an N-type drift region in contact with an oxide layer. A P-type region is provided above the N-type drift region, having a portion more heavily doped with P-type dopants. The double RESURF structure can be provided by a buried oxide layer, a floating doped region, or a horizontal PN junction. The IGBT can be utilized in various power operations, including a matrix switch or a voltage source converter.

Abstract: A method and apparatus for minimizing motor instability under no load conditions, the method including identifying instability by comparing consecutive current half cycle periods and, where the difference between half cycle periods is sufficiently large, determining that instability exists and modifying controller modulating waveforms by reducing waveform magnitude until stability is achieved. Preferably the apparatus for achieving stability includes only a single current zero crossing sensor to minimize hardware costs.

Abstract: A loosening-resistant threaded fastener system and method of use includes a washer that is axially movable on a threaded stud, a threaded nut having threads which cooperate with the threaded stud, and a washer anti-rotation mechanism to prevent the washer from rotating on the stud about a fastening axis. One of the washer and the nut may include a plurality of protrusions while the other of the washer and the nut has a plurality of detents. The protrusions and the detents engage one another at a plurality of angular positions. Rotating the nut on the stud while in contact with the washer results in distinct, audible clicks which may be counted to obtain a pre-determined tightness.

Abstract: A redundant industrial controller system has a primary controller backed up by a secondary controller and recovers from a power loss by analyzing the state memories of the controllers to reach a determination of which controller would best be suited to assume primary control status without resorting to arbitrary tie-breaking procedures or race conditions. The rules and their inputs are applied by both controllers which independently make the determination as to which controller should be the primary controller.

Abstract: On-line upgrading of a primary industrial controller is provided through the use of a secondary industrial controller that may assume control of the process controlled by the primary industrial controller. A switch-over of control is orchestrated by a system back-up module that may detect removal of the functional components of the primary industrial controller to initiate the switch-over. Determination of removal of functional modules may be provided by a periodic polling of the functional components on the interconnecting communication link. The system back-up module designates one of the functional modules to poll the system back-up module so that complete coverage of removable components may be had.

Abstract: A motor controller produces independent first and second drive power signals for independent application to first and second linear motor stages movable on the same path. Each armature winding in the path is connected to a first switch receiving the first drive power and to a second switch receiving the second drive power. A first switch control device associated with the first linear motor stage actuates the first switches in its vicinity, while leaving the remaining first switches unactuated. A second switch control device associated with the second linear motor stage actuates the second switches in its vicinity, while leaving the remaining second switches unactuated. Each linear motor stage has an encoder associated with it to inform the motor controller of its position and/or motion.

Abstract: A method and apparatus used with a field oriented motor controller for providing corrected transient inductance estimates during normal motor operation. The invention monitors q-axis feedback and command voltages and, based on an error therebetween, modifies a transient inductance estimate to compensate for the error and force the feedback voltage to equal the command voltage thereby facilitating field oriented control. The invention can be used either during a commissioning procedure to provide an inductance correction table for use during normal motor operation or can be used during normal motor operation to tune the inductance estimate.

Abstract: Inter-operability of products connected together to form an industrial control system is determined by defining each product as a set of services describing points of interface between the products and by determining complementary services necessary for inter-operability from a table listing complementary services. A new product may be evaluated for inter-operability by comparing its services to services of products with which inter-operability is desired. In one mode of operation after definition of the products in which inter-operability is desired, a necessary list of services is compiled from a database and translated by a relationship map to complementary services which define a virtual product having the desired inter-operability. Inter-operability of an entire control system may be thus modeled prior to construction.

Abstract: An industrial controller provides a primary controller and a redundant secondary controller and allows switchover between the controllers in the event of a failure in the primary controller. The process of qualification of the secondary controller in which its programming is made to match the primary controller may be inhibited to permit the secondary controller to maintain a clean version of an upgraded program executing on the primary controller. The clean program may be reverted to in the event an upgrading of the program in the primary controller is unsuccessful. Switchover is permitted even though the qualification of the secondary controller is not enabled.

Abstract: A redundant controller employs connection-based messaging to ensure reliability and determinacy in communications. The need to close connections and reopen connections with a backup module when control switches from a primary controller to a secondary controller is eliminated by keeping the secondary controller updated as to the connections that have been opened and having the secondary controller assume the connection identification numbers of the primary controller upon switch-over.

Abstract: In one embodiment, the present invention relates to a polymer prepared from a mixture containing a polymerization material and a polycondensation product of a partially hydrolyzed chelated metal oxide precursor. In another embodiment, the present invention relates to a process for making a polymer involving contacting a polymerization material with a metal oxide sol comprising a liquid and a polycondensation product of a partially hydrolyzed chelated metal oxide precursor to form a mixture and at least one of polymerizing and curing the mixture of the polymerization material and the polycondensation product.

Abstract: A motion controller includes an input for receiving data corresponding to moves in a cycle of a multi-axis machine. The controller controls electric motors of the machine in accordance with positions set forth in a path planning table. The path planning table is generated from the data by applying a curve defining equation and integrating an alpha variable therein. The alpha variable corresponds to a velocity to acceleration ratio and is adjustable to allow the calculation of a new path planning table having a velocity and acceleration profile shifted from an initial velocity and acceleration profile to allow for optimization of motor performance. A method of path planning having user tunable parameters is also provided.

Abstract: An apparatus for converting three phase AC supply line voltages to DC voltage on a DC bus, the apparatus including a master converter subsystem and at least one slave converter subsystem wherein each subsystem includes a current regulator, a PMW modulator and a converter, the master converter linked to the supply lines and the slave converter linked to the supply lines via intermediate lines, each regulator receiving a current command signal and generating modulating signals, each modulator using a carrier signal and modulating signals from a corresponding regulator to generate control signals to control a corresponding converter, the intermediate lines linked to a common mode choke for essentially eliminating common mode currents in the intermediate lines.

Abstract: A coupling/mounting system for securing a shaft to a sleeve or hub includes an inner insert or bushing and an outer insert or bushing. The inner bushing has a slot permitting its radial compression during insertion into the hub. One or more radially extending projections are provided about the cylindrical outer periphery of the inner bushing. The projections enter into engagement in a corresponding recess within the bore. The inner bushing has a tapered inner surface that contacts a corresponding tapered outer surface of the outer bushing. The outer bushing has a elongated slot that permits its radial compression about the shaft when the system is assembled. The outer bushing includes mechanical features which permit it to be drawn into engagement between the inner bushing and the shaft, and thereby to exert radial forces for securing the shaft to the bore.

Abstract: An inductive proximity sensor and a method of proximity sensing are described that permit targets of interest to be detected despite the presence of external magnetic fields due to AC or DC sources, such as resistive welding machines. The sensor has a pair of matched coils positioned adjacent to one another along a common central axis. The coils are coupled in series with oscillator and detecting circuitry, that also serves to drive a switching device. The coils are wound for current flow in opposite directions and produce oscillating electro-magnetic fields for detecting the targets in response to signals from the oscillator and detecting circuitry. Currents in the coils induced by strong external magnetic fields produces an additional components of the coil field which essentially cancel one another. The sensing field of the coil assembly may be shaped and directed by cooperation of the fields of the two coils and by appropriate shielding around one or both coils.

Abstract: Lead wires of large electric motors are routed through annular shrouds located inside of the motor housing to surround respective stator coilheads. Each of the shrouds includes at least one attachment portion defining an opening for passage of the leads. In one embodiment, a support element defining a lead channel aligns with the lead opening. The support element includes a mounting structure for attachment of a conduit box thereon. A seal arrangement having a planar seal element may be provided in the lead channel to support and separate the individual leads, while providing a seal to inhibit passage of cooling air from the housing interior into the conduit box. In another embodiment, a cover arrangement is attached directly to the attachment portion of the shroud. The cover arrangement may include a flexible gasket juxtaposed to a rigid cover plate.

Abstract: A method and system for diagnosing the behavior of a machine which performs a discrete event process. A diagnostic engine observes occurrences of discrete events to detect timing patterns. A statistical analysis is performed on repetitions of the timing patterns, thus providing the basis for defining diagnostic rules. The rules are updated in real time and are subject to a rule competition procedure in which only the most precise and efficient rules are selected. Further occurrences of discrete events are evaluated relative to the diagnostic rules to identify and predict malfunctions of the machine.

Abstract: A pass-through table is developed to work in conjunction with an I/O table of a centralized industrial controller to permit a centralized controller to work seamlessly with a highly distributed control system. The pass-through table indicates data used in common between the centralized controller and the distributed controller and monitors a link connecting the distributed controller for changes in variables on the pass-through table to write those changes to the I/O table of the centralized controller. Conversely, changes in the I/O table of the centralized controller are detected and transmitted out to the common link to the distributed controller.

Abstract: A method of reconstructing a control program from portions of that program contained in distributed processor modules of a distributed control system links each portion of the program with a source identifier. When the portions are collected, they are sorted by source identifier and merged to reveal the original control program as may be required for editing or the like.

Abstract: A biasing assembly for a switching device is formed in a modular enclosure that may be mounted on either left or right sides of the switching device. The biasing assembly interfaces with the switching device to rapidly move the switching device between first and second stable positions, such as corresponding to open and closed contact orientations. The biasing assembly includes a hub and link plate coupled to a spring assembly. A spring in the spring assembly is precharged by initial movement of an actuating handle. Once a predetermined intermediate position is reached, a double roller arrangement is displaced along a support surface to rapidly toggle the spring assembly, link plate and hub to a second position. The enclosure includes abutment surfaces for stopping and holding the link plate in stable positions. The rolling contact afforded by the spring assembly rollers permits extremely rapid displacement and rolling friction during displacement of the assembly.