Abstract:
A system to determine altitude and velocity of an aircraft including antennas to transmit beams to the ground surface and receive information from the beam once it is reflected back to the antenna upon hitting the ground surface. This information is used to determine altitude. Based on the altitude information and a gating arrangement, velocity is determined.
Abstract:
A method for use in vehicle attitude determination includes generating GPS attitude solutions for a vehicle using three or more antennas receiving GPS signals from two or more space vehicles. An inertial navigation system is initialized by setting the attitude of the inertial navigation system to a GPS attitude solution generated for the vehicle and/or the attitude of the inertial navigation system is updated using the GPS attitude solutions generated for the vehicle or GPS estimated attitude error generated for the vehicle. A system for use in vehicle navigation is also provided. The system generally includes three or more GPS antenna/receiver sets associated with a vehicle, an inertial measurement unit that provides inertial measurements for the vehicle, a processing unit of the system having the capability for generating GPS attitude computations for the vehicle using the three or more GPS antenna/receiver sets and signals from two or more space vehicles; the GPS attitude computations include at least one of absolute attitudes and estimated attitude errors. The processing unit of the system also includes a filter for generating estimates of attitude for the vehicle using the inertial measurements from the inertial measurement unit and the attitude computations.
Abstract:
A multipath detection method for use in a GPS position determination system includes providing a code pseudorange measurement representative of a range of an antenna to a space vehicle and a carrier phase pseudorange measurement representative of the range of the antenna to the space vehicle. A code-carrier measurement difference is then generated between the code pseudorange measurement and the carrier phase pseudorange measurement. This code-carrier measurement difference is examined to determine if a multipath component is present. If the difference indicates that multipath is likely to be present, use of such measurements in computing position solutions, such as attitude solutions, is avoided. A multipath detection system for carrying out the method is also described.
Abstract:
A module (56) of a distributed process control system has a prior art kernel submodule (16'), a peripheral submodule (59), and an interface circuit (58) to provide for communications between the two submodules. The kernel submodule communicates with the interface circuit over a module BUS (18') which includes a data BUS and an address BUS. The peripheral submodule communicates with the interface circuit over a peripheral component interface (PCI) BUS (60), a single thirty two bit BUS which is incompatible with the module BUS. The interface circuit permits such communications between the two submodules without requiring any hardware or software changes to the kernel submodule and the module BUS, nor to components of the peripheral submodule or its PCI BUS. The interface circuit includes interface registers, a control circuit which determines which submodule is permitted to write or read data and/or address into or from a given register of the interface registers. Input circuits controlled by control signals produced by the control circuit determines the source of the data and/or addresses written into a given register. An output circuit under the control of the control circuit determines the BUS over which the contents of a given register are transmitted to the addressed submodule.
Abstract:
A communications system capable of providing enhanced data integrity and reliability through redundant buses (107R, 107L, 107LB), and a network interface controller for use therewith are disclosed. Redundant conductors (107) conforming to well-known ethernet standards interconnect electronics components. Each component communicates with the conductors (107) through a single network interface card (NIC). Each NIC comprises an ethernet compliant transceiver (101A-C) for each ethernet conductor (107) in communication with the component. Microcontrollers (112) embedded in each NIC synchronously and deterministically place data on the ethernet conductors (107) according to a timing scheme stored in a non-volatile memory (113) means. A heartbit/power monitor (114) is also provided to ensure that data cannot be transmitted in the event of a microcontroller (112) failure. Through the inventive elements presented herein, the communications system provides a high degree of redundancy and fault-tolerance and is therefore well-suited to critical applications in avionics communication.
Abstract:
The present invention is an optical transmission system comprising an optical source, a first lens and a second lens, a multimode optical waveguide, and a phase-only filter. The optical source generates an optical signal having a predetermined wavelength which is received by the first lens. The signal is then sent from the first lens through the phase-only filter and then to the second lens. The second lens then focuses the signal into the multimode optical waveguide. The multimode optical waveguide has predetermined dimensions and has multiple modes. The phase-only filter excites a plurality of modes in the optical waveguide to approximate equilibrium modal power distribution as the optical signal is received into the optical waveguide.
Abstract:
A system for, and method of, generating a control drawing representing interconnections among elements of a real-time process control system and a plant controlled thereby. The system includes: (1) a memory that receives and stores textual input data representing explicit point connections among the elements, control language scripts containing implicit point connections among the elements and data regarding a starting element and (2) a processor, coupled to the memory, that analyzes the explicit and implicit point connections relative to the starting element and automatically constructs the control drawing as a function of the starting element, the system thereby generating the control drawing representing the interconnections.
Abstract:
A system for, and method of, translating a source visual display file having a plurality of related non-Component Object Module ("COM") objects arranged in a source file format into a destination visual display file having a destination file format. The system includes: (1) a reading circuit that reads the plurality of related non-COM objects of the source visual display file, (2) a transposition circuit that transposes at least some of the plurality of related non-COM objects from the source file format into the destination file format, and (3) a translation circuit that converts at least some of the transposed plurality of related non-COM objects into COM objects, the source visual display file thereby translated into the destination visual display file capable of generating a visual display substantially similar to the source visual display file.
Abstract:
The assembly comprises a U-shaped frame to which the card may be secured. The frame is defined by spaced parallel side elements and a connecting end element. Intermediate the ends of the frame a tie bar bridges flatly across the top of the frame and is adapted to hold down the card and tie the side elements together. The bar has downward legs at its opposite ends secured to the frame.
Abstract:
There is provided a process control system having a display program that permits a program designer to create and edit dynamic picture objects in a persistent heap and save the heap to a storage medium. The display program rapidly reads the dynamic picture objects from the storage medium and invokes the objects for viewing on the system's interactive display. When the persistent heap is subsequently read from the storage medium by an operator, the dynamic picture objects stored in the heap do not need to be instantiated and, thus, invocation of the objects is accelerated and optimized. Accordingly, the persistent heap greatly improves the speed in which picture objects can be read from the storage medium, processed by the display program and called-up to the interactive display.