Abstract: A rigid riser system including a rigid riser and one or more fatigue performance enhancers. The rigid riser includes a plurality of rigid metal sections welded together to form a plurality of girth weld joints. The one or more fatigue performance enhancers are positioned over one or more of the plurality of girth weld joints of the rigid riser to enhance the fatigue resistance and/or fatigue life. The body of the fatigue performance enhancer may include a central region and two end regions with the central region having a greater average radial cross-sectional thickness than each of the end regions. Methods of enhancing fatigue performance of the rigid riser and fatigue performance enhancers are also disclosed.

Abstract: A rigid riser system including a rigid riser and one or more fatigue performance enhancers. The rigid riser includes a plurality of rigid metal sections welded together to form a plurality of girth weld joints. The one or more fatigue performance enhancers are positioned over one or more of the plurality of girth weld joints of the rigid riser to enhance the fatigue resistance and/or fatigue life. The body of the fatigue performance enhancer may include a central region and two end regions with the central region having a greater average radial cross-sectional thickness than each of the end regions. Methods of enhancing fatigue performance of the rigid riser and fatigue performance enhancers are also disclosed.

Abstract: A development tool combines advantages of a simulation tool with an object-oriented modeling tool, including a real-time mathematical matrix library and an object model. The tool is applicable to any intelligent control system. A composite object group (COG) contains both sampled-data and event-driven capabilities. COGs merge procedural and object-oriented programming, and provide explicit, graphical integration of both types of processing and are fully hierarchical. A control system is built up of object-oriented components, including these types: atomic, interface, data flow and state transition. A finite state machine (FSM) component is built from states, transitions, events and state transition components. Data flow components provide sampled-data capabilities. FSMs provide event-drive capabilities. Each component may include methods and attributes.

Abstract: A composite object group (COG) data structure embodied in a computer-readable medium for building a control system that has both a clock cycle and event processing is provided. An interface for passing information to and from the COG data structure is provided. One or more data flow objects are provided in the COG to accept input data and to produce output data on the clock cycle. The data flow object is connected to the interface and provides sampled-data processing for the control system. One or more state machine objects are provided in the COG; each includes a plurality of states and a plurality of transitions between the states that are each triggered by an event. The state machine object provides event-driven processing for the control system, whereby the COG data structure provides both sampled-data and event-driven processing for the control system.

Abstract: A development tool combines advantages of a simulation tool with an object-oriented modeling tool, including a real-time mathematical matrix library and an object model. The tool is applicable to any intelligent control system. A composite object group (COG) contains both sampled-data and event-driven capabilities. Mapping the computing resources of a computing device throughout the hierarchy of a control system is provided for modes, executable programs and threads of a processor. Within a given processor, each component of a control system may be assigned to individual execution threads within that processor simply by naming a thread.