Abstract: The present invention provides a method and apparatus for adaptive control which does not require a predetermined model of the process to be controlled. The method comprises the steps of 1) setting an initial state vector; 2) setting an initial parameter vector; 3) setting an initial prediction parameter gain; 4) set the initial covariance matrix; 5) performing a state update 6) estimating the model error; 7) updating the parameter vector, 8) updating the co-variance matrix, and 9) updating the controller output.

Abstract: An elongated pneumatic plug is provided for sealing pipelines. The pneumatic plug has a body structure with a first end cap element, a second end cap element and an expandable elastomeric sleeve with a fixed outer diameter. A fluid ingress and egress valve is located in the first end element which is positioned adjacent the first segment of the sleeve structure. The elastomeric sleeve structure has a specified length and varying wall thicknesses at specified segments along its length. The segmented lengths comprise a middle segment having a predetermined wall thickness, a first segment having a thickness in a range of approximately 50-65% of the middle segment thickness and a second segment having a thickness in a range of approximately 65-80% of the middle segment thickness. The segmented sleeve structure provides an ordered and staged inflation and deflation of the pneumatic plug body.

Abstract: An adjustable pressure relief valve for use in a fluid pressurized system. The pressure relief valve has a valve body with a passage that terminates at inlet and outlet ends. The passage includes a valve chamber, a valve seat at the inlet end, and a valve base adjustably secured proximate the outlet end. A valve head sealingly engages the valve seat by a spring that is interposed between the valve head and the valve base. The valve body is constructed and arranged for use as an end cap in a flexible pressurized system, such as a pneumatic pipeline plug.

Abstract: A network control and test system for application to data communications networks. In a first mode of operation, the system learns the network configuration automatically and builds a table describing the network configuration. In a second mode of operation, the system automatically monitors the status of the network and each of its component units, periodically polling the network for changes of status and updating the information in the network configuration table to reflect such changes. In a third mode of operation, selective sites in the network may be tested under control of the system at previously selected and entered times of day, at which times previously chosen tests are performed without the need for operator intervention. In a fourth mode, an operator can manually command the system to perform certain tests and control functions.

Abstract: A network control and test system for application to data communications networks. In a first mode of operation, the system learns the network configuration automatically and builds a table describing the network configuration. In a second mode of operation, the system automatically monitors the status of the network and each of its component units, periodically polling the network for changes of status and updating the information in the network configuration table to reflect such changes. In a third mode of operation, selective sites in the network may be tested under control of the system at previously selected and entered times of day, at which times previously chosen tests are performed without the need for operator intervention. In a fourth mode, an operator can manually command the system to perform certain tests and control functions.

Abstract: A testing facility for a data communications network including modulators and demodulators, or modems, at central sites, at intermediate, or hubbing, sites, and at remote sites. Hubbing site testing units connect to respective host modems at the intermediate sites. The central testing unit transmits control words containing line address, drop address, and command characters. A configuration control circuit in each hubbing site testing unit generates signals that designate the particular location of the testing unit at the hubbing site. A validation circuit in each testing unit enables the testing unit to respond to the command character if two valid control words are received in succession. Thereafter the testing unit transmits back to the central testing unit signals in response to the test defined by the command character.

Abstract: A modem with transmitter and receiver sections. Incoming digital data signals produce successive coordinate signals to define successive transmission points representing a given digital value and to modulate quadrature carrier signals. The coordinate signals have unit values of 0, 1, 2.707, 3 and 5 and together control the amplitude and phase of the modulated carrier signals. The receiver section uses received coordinate signals, after they are properly conditioned, to select a decision region which corresponds to a transmission point to produce the digital data signals. The decision regions have rectilinear boundaries on a Cartesian coordinate system at unit values 0, 1.25, 2 and 4 and each region is either rectangular or non-rectangular. Digital synchronism between separate modems is maintained by transmitting coordinate signals corresponding to a framing point which is separate from the transmission points, but which has the same digital value as a transmission point.

Abstract: A modem with transmitter and reciever sections. Incoming digital data signals produce successive coordinate signals to define successive transmission points representing a given digital value and to modulate quadrature carrier signals. The coordinate signals have unit values of 0, 1, 2.707, 3 and 5 and together control the amplitude and phase of the modulated carrier signals. The receiver section uses received coordinate signals, after they are properly conditioned, to select a decision region which corresponds to a transmission point to produce the digital data signals. The decision regions have rectilinear boundaries on a Cartesian coordinate system at unit values 0, 1.25, 2 and 4 and each region is either rectangular or non-rectangular. Digital synchronism between separate modems is maintained by transmitting coordinate signals corresponding to a framing point which is separate from the transmission points, but which has the same digital value as a transmission point.