Abstract: A display and user interface incorporated into an on-board engine vibration monitoring and trim balance system. The interface consists of an alphanumeric display and a number of push buttons integrally formed with a front panel of the system. The user operates the interface to obtain and alter information pertaining to engine vibration data, engine trim balance solutions, and balance part configurations. Push buttons are used to scroll through an elaborate menu structure for receiving information and making selections among various available functions. The menu structure may in particular provide for the user to review particular installed balance part location data prior to asking the system to compute an optimum balance solution. Once the balance solution is calculated, the user may review a list of balance parts to be removed from and installed on the engine.

Abstract: This invention disclosure describes an intelligent sensor system in which different types of sensors are connected to a network communication bus. Analog and digital signals are transferred bi-directionally on the common communication bus between the distributed sensors and an application specific controller referred to as a bus converter/controller module (BCM). The traditional analog type sensors are connected to the communication bus through interface devices referred to as transducer-to-bus interface modules (TBIM). The TBIM provides sensor identification, self-test and data correction functions.

Abstract: An aircraft engine vibration analysis system is provided with at least one vibration sensor disposed proximate an aircraft engine. The analysis system is further provided with a vibration analysis module for receiving an input from the vibration sensor and generating an output representative of vibration characteristics of the aircraft engine. The analysis module is provided with a multiple pin input port which is connectable to the vibration sensor. The analysis module is further provided with test sequence select circuity which is in electrical communication with the input port for implementing an appropriate vibration analysis sequence in response to measured conductivity between pins of the multiple pin input port. The analysis system is further provided with a sensor connecting cable which is connectable to the vibration sensor and the analysis module input port.

Abstract: A piezoceramic accelerometer of the cantilever bending-beam bimorph type is provided with housing structure of straightforward easily-manufactured design. Because of its design features, the accelerometer is comparatively low in cost, rugged, reliable, and inherently low in internal capacitance. Consequently, a self-generated signal of favorable value proportionate to applied acceleration is provided by the accelerometer. The accelerometer provides for use of Surface Mount Technology (SMT), which allows further manufacturing cost reductions in uses of the accelerometer.

Abstract: A method and apparatus for self-testing a transducer system. A signal generator is used to generate a predetermined sequence of signals or pulses, and the sequence has a finite test-time duration. The self-test signal also has the properties that its time varying part: (1) sums to zero over the test time interval; and (2) it has a relatively flat frequency spectrum. Additionally, calculations are made even simpler if the self-test signal is chosen to switch at pseudo random intervals between two fixed values. The output of the self-test system has one term which is directly proportional to the transducer system sensitivity and represents the desired self-test result, and one or more error terms which tend toward zero as the test-time duration increases. The self-testing system of the present invention may be implemented either in analog circuitry, digital logic, or a combination thereof.

Abstract: A high-temperature, low-noise coaxial cable assembly with high strength reinforcement braid is depicted and described. The cable assembly has very low self-noise generation and is particularly useful for telemetry and instrumentation purposes. Also, the cable assembly offers a tensile strength about an order of magnitude greater than conventional cable assemblies, and resultant improved service life and durability.

Abstract: A differential variable capacitance acceleration sensor includes a sandwich structure having three stacked plates of silicon with the center plate mounted such that its center portion is enabled to move in a sealed cavity with each side thereof moving toward and away from a fixed cooperating plate forming the opposite side of a capacitive circuit. The center portion or mass of the center plate is suspended from its rim by means of a large number of integral fingers extending from the rim to the top and bottom surfaces of the center portion. This center mass includes a number of through holes to permit the passage of air from one side to the other and may also include grooves to aid in the flow of air. The fixed top plate or lid and the base also have, or may have, grooves to assist in the passage of air. An alternative embodiment includes a smaller number of more compliant fingers to provide a more compliant structure.

Abstract: A strain sensitive element for use in a system for converting mechanical movement of relatively movable portions of the element into electrical signals, includes a substantially planar substrate comprising an N-type silicon crystal material wherein the substrate includes one or more grooves extending into the substrate defining an integral hinge portion between at least two relatively movable parts. At least one unitary strain gage extends across a groove without any separate support so that the strain gage and the hinge portion are spaced apart. The strain gage is a unitary member derived from the same silicon crystal material of the substrate and comprises P-type silicon material. The strain gage is joined to two of the relatively movable parts of the substrate. At least one unitary conductor extends across a groove without separate support so that the conductor and the hinge portion are spaced apart.

Abstract: A strain sensitive element for use in a system for converting mechanical movement of relatively movable portions of the element into electrical signals, includes a substantially planar substrate comprising an N-type silicon crystal material wherein the substrate includes groove means extending into the substrate defining an integral hinge portion between at least two relatively movable parts. At least one unitary strain gage extends across the groove means without any separate support so that the strain gage and the hinge portion are spaced apart. The strain gage is a unitary member derived from the same silicon crystal material of the substrate and comprises P-type silicon material. The strain gage is joined to two of the relatively movable parts of the substrate. At least one unitary conductor extends across the groove means without separate support so that the conductor and the hinge portion are spaced apart.