Abstract: A tilt switch based on differential threshold sensing includes a tilt track (such as a tilt tube), and a tilt/target element moveable along the tilt track by gravity between first/second ends based on tilt angle. An inductive sensor includes first/second sense coils at the ends of the tilt track, and sensor circuitry (a) to drive each sense coil to project a magnetic sensing field, and to measure a differential sensor to a position of the tilt/target element relative to the sense coils, based on a property corresponding to sense coil inductance (for example, relative to a pre-defined switching threshold position), and (b) to provide, in response to the differential sensor response, a tilt switch output corresponding to a tilt angle of the tilt track based on a position of the tilt/target element relative to the sense coils (or switching threshold), for example, with a pre-defined hysteresis.

Abstract: A system for estimating fluid flow in a system including a pump and a fluid vessel operatively coupled to the pump via a conduit is described herein. The system comprises an accelerometer affixed to an exterior surface of the conduit, wherein the accelerometer is configured to generate signals representing physical movement of the conduit, and wherein the signals are suitable for estimating fluid flow in the conduit.

Abstract: A system for estimating fluid flow in a system including a pump and a fluid vessel operatively coupled to the pump via a conduit is described herein. The system comprises an accelerometer affixed to an exterior surface of the conduit, wherein the accelerometer is configured to generate signals representing physical movement of the conduit, and wherein the signals are suitable for estimating fluid flow in the conduit.

Abstract: A cockpit yoke assembly adapted for mounting on top of a RC transmitter for controlling the operation of a model airplane. The yoke assembly includes a first control arm with a throttle knob. The first control arm is attached to a first ball and socket linkage adapted for attachment a first joystick on the transmitter. A rudder control lever is attached to the first control arm. The yoke assembly includes a second control arm with an elevator knob. The second control arm is attached to a second ball and socket linkage adapted for attachment to a second joystick on the transmitter. An aileron control lever is attached to the second control arm. The first and second ball and socket linkage are used for moving the first and second joysticks fore or aft and left or right during the operation of the model airplane.

Abstract: Various embodiments of the present invention include systems and methods for assessing the performance of an actuator of a attitude control system (ACS), such as a control moment gyroscope (CMG). In one embodiment, a system includes a support bracket assembly coupled to an actuator, wherein the actuator is configured to generate an output torque. The system also includes at least one sensor assembly coupled to the support bracket assembly, wherein the at least one sensor assembly includes a sensor configured to measure the output torque about at least one axis of the support bracket assembly while the support bracket assembly remains substantially motionless.

Abstract: Various embodiments of the present invention include systems and methods for assessing the performance of an actuator of an attitude control system (ACS), such as a control moment gyroscope (CMG). In one embodiment, a system includes a support bracket assembly coupled to an actuator, wherein the actuator is configured to generate an output torque. The system also includes at least one sensor assembly that includes a sensor configured to measure the output torque about at least one axis of the support bracket assembly while the support bracket assembly remains substantially motionless.

Abstract: A method for determining a change in a mass of a fan impeller. The method includes inducing a torque to the fan impeller and determining a change in the angular speed of the fan impeller, induced by the torque. A value for a first parameter representing a present mass of the fan impeller is determined on the basis of the change in the angular speed and the torque. The change in the mass is then determined on the basis of the first parameter and a second parameter representing the reference mass of the fan impeller.

Abstract: A personal navigation device configured to determine heading readings continuously using data from a sensor in the personal navigation device. Heading readings are selected corresponding to a periodic event. A representative heading is determined from the selected heading readings. When a portion of the selected heading readings has a value within a range of the representative heading, a static heading indicator is asserted to indicate the personal navigation device is moving in a static heading. The static heading indicator may be used to smooth an estimated trajectory of the personal navigation device.

Abstract: A device for detecting and measuring a change in angular position with respect to a reference plane is useful in surgical procedures for orienting various instruments, prosthesis, and implants with respect to anatomical landmarks. One embodiment of the device uses three orthogonal rate sensors, along with integrators and averagers, to determine angular position changes using rate of change information. A display provides position changes from a reference position. Various alignment guides are useful with surgical instruments to obtain a reference plane.

Abstract: An inertial measurement unit is disclosed which includes a system of gyros for sensing angular rates, a system of accelerometers for sensing angular accelerations, an integrator for deriving gyro-less angular rates from the sensed angular accelerations, and a complimentary filter for blending the sensed angular rates and the gyro-less angular rates to produce a virtual angular rate output for the inertial measurement unit.

Abstract: Systems and methods for detecting a vehicle static condition are provided. In this regard, a representative system includes a sensor operative to detect at least one of acceleration and angular rate of a vehicle. The sensor is further operative to generate a vehicle vibration profile based on the at least one of the detected acceleration and angular rate of the vehicle. The system further includes a computing device operative to receive the vehicle vibration profile from the sensor, the computing device being further operative to determine whether the vehicle is stationary or moving based on the vehicle vibration profile.

Abstract: A technique is disclosed which offers an improvement in the performance of an atom interferometric (AI) sensor, such as one that is used in an accelerometer or a gyroscope. The improvement is based on the recognition that the AI-based device, which is associated with superior low-frequency performance, can be augmented with a conventional device having a superior high-frequency performance, as well as a wider frequency response, compared with that of the AI-based device. The disclosed technique combines acceleration measurements from the AI-based device, which is characterized by transfer function G(s), with acceleration measurements from the conventional device that have been adjusted by a complementary function, 1??(s), where ?(s) is an approximation of G(s). The conventional device has a considerably wider bandwidth than that of the AI-based device, and the quasi-unity transfer function of the conventional device makes possible the 1??(s) adjustment of the measurements provided by the conventional device.

Abstract: Method and apparatus for measuring the coefficient of rolling friction or speed of a horizontal surface over which a round object is rolled such as a putting green encountered in the game of golf. The method includes a device for launching a ball across the surface at a constant and consistent velocity. An included timing device is triggered to start counting the elapsed time when the ball exits the launching device and continues counting until the ball has decelerated to a stop. At the instant the ball ceases moving the timer is triggered to terminate the count. The time required for a body with a specific velocity to come to rest after experiencing constant deceleration is determined by the laws of motion. The coefficient of friction or “speed” of the green which is proportional to the amount of deceleration may then be calculated. This time measurement is therefore sufficient to determine the speed of the green surface which may be reported as an equivalent “stimp” value.

Abstract: An integral connectorless hermetically sealed high-temperature piezoelectric sensor housing and cable assembly includes signal conditioning/processing circuitry having a charge amplifier-differential amplifier combination with integral trim capacitor and/or a voltage divider network in at least one signal processing path to provide the ability to custom adjust input impedances and balance common-mode signals to compensate for inequalities caused by inherent parasitic capacitances and specific structural constraints of the sensor assembly.

Abstract: The alignment of railway tracks may be monitored using an accelerometer (36) mounted on a bogie (24) of a railway vehicle to detect lateral accelerations, and a displacement transducer (38) to monitor the lateral displacements of a wheelset (27) relative to the bogie. The acceleration signals are digitised, and processed corresponding to double integration, so as to deduce the lateral displacements of the bogie, and in conjunction with the signals from the displacement transducer hence to determine the effective lateral displacements of the track. This can provide a more useful indication of the lateral positions of the rails than measurements of the gauge faces. Such equipment (16) may be installed in a service vehicle, and operate automatically, downloading resulting data to a remote base station at regular intervals.

Abstract: A method and system for analyzing the transfer of motion to a subject on a sleeping surface. A mattress is positioned on a frame, and a subject is positioned on the mattress. A sensor is placed in communication with the subject. The surface adjacent the subject is moved by means of a moving mass, and the sensor detects the motion of the subject. Motion transferred to the subject as a result of the mattress moving is measured and recorded.

Abstract: A transducer includes a body mountable to a vehicle spindle and a plurality of accelerometers coupled to the body. The plurality of accelerometers measure acceleration of the body. A calculation circuit coupled to the plurality of accelerometers receives output signals therefrom and converts the measured acceleration to displacement signals indicative of displacement of the body in a coordinate system.

Abstract: A transducer includes a body mountable to a vehicle spindle and a plurality of accelerometers coupled to the body. The plurality of accelerometers measure acceleration of the body. A calculation circuit coupled to the plurality of accelerometers receives output signals therefrom and converts the measured acceleration to displacement signals indicative of displacement of the body in a coordinate system.

Abstract: Comparable values for the heights of the individual jumps in a series of multiple jumps can be achieved, if defined initial conditions for first and second successive integrations of measured vertical forces are given for each individual jump. The initial condition for the first integration is taken as a zero velocity in the middle of the flight time interval for each individual jump. For every second integration, as initial condition for the jump height, a constant initial height is taken. This is a characteristic value of the test person.

Abstract: An acceleration recorder and related method for monitoring, discriminating, and recording acceleration events only when the acceleration and calculated velocity change both exceed selected trigger values. While the acceleration values meet a first, user-defined threshold, the acceleration values are integrated to calculate a velocity change value. If the velocity change value meets a second, user-defined threshold, the acceleration event, including the velocity change, is recorded in memory.

Abstract: A system for protecting a pendulous oscillating gyroscopic accelerometer (POGA) from power failure interruption (PFI) events, the POGA having a servo driven member (SDM), rotor driven member (RDM), and torque summing member (TSM), wherein the POGA is a part of an accelerometer system of a guidance system which detects such events and communicates them to the accelerometer system. In the invention, the acceleration is stored just prior to the PFI induced system shut-down, and after the PFI the POGA drives are turned back on. The velocity change during the PFI is determined based on the TSM deflection occurring during the PFI event, acceleration existing at the beginning, and elapsed time. This is reported to the guidance system in a timely fashion.

Abstract: Method and apparatus for detecting mechanical vibrations and outputting a signal in response thereto. An accelerometer package having integral display and control functions is suitable for mounting upon the machinery to be monitored. Display circuitry provides signals to a bar graph display which may be used to monitor machine conditions over a period of time. Control switches may be set which correspond to elements in the bar graph to provide an alert if vibration signals increase in amplitude over a selected trip point. The circuitry is shock mounted within the accelerometer housing. The method provides for outputting a broadband analog accelerometer signal, integrating this signal to produce a velocity signal, integrating and calibrating the velocity signal before application to a display driver, and selecting a trip point at which a digitally compatible output signal is generated.

Abstract: A small and inexpensive bearing-distance sensor capable of detecting a travel bearing and a travel distance of a vehicle. The bearing-distance sensor includes a rectangular parallelepiped case. A first acceleration sensor and a second acceleration sensor are mounted within the case. The first acceleration sensor detects an acceleration in a first direction, e.g. the longitudinal direction of the case, to obtain a signal related to the acceleration, and the second acceleration sensor detects a force applied in the width direction of the case, which is perpendicular to the first direction, to obtain a signal related to that force. The travel distance of the vehicle is found from the output signal of the first acceleration sensor, and the travel bearing of the vehicle is found from the output signals of the first and second acceleration sensors.

Abstract: A small size apparatus for measuring and recording acceleration comprises an acceleration sensor, an A/D converter which converts the output signal of the acceleration sensor to a digital signal, a control element which processes the digital signal, a detachable external memory device which stores data of a change in acceleration and, a battery for supplying electric power to the sensor, the A/D converter, the control element and the external memory device. The small size apparatus is mounted on a moving body to be measured and the entire small size apparatus is driven by the battery. The correct attachment of the external memory device is detected by steps of writing data into a special address, reading the data out thereafter, and comparing the written data and read data. When the read data coincides with the written data, it is judged that the external memory device is correctly attached.

Abstract: Method and apparatus for detecting mechanical vibrations and outputting a signal in response thereto. Art accelerometer package having integral display and control functions is suitable for mounting upon the machinery to be monitored. Display circuitry provides signals to a bar graph display which may be used to monitor machine conditions over a period of time. Control switches may be set which correspond to elements in the bar graph to provide an alert if vibration signals increase in amplitude over a selected trip point. The circuitry is shock mounted within the accelerometer housing. The method provides for outputting a broadband analog accelerometer signal, integrating this signal to produce a velocity signal, integrating and calibrating the velocity signal before application to a display driver, and selecting a trip point at which a digitally compatible output signal is generated.

Abstract: A device for determining position uses three voltage dividers. Each voltage divider is a metal conductor having a head on one end and two legs on an opposite end. The tips of the legs of each of the bodies are located in planes which are perpendicular to the other bodies. A DC voltage is applied to the head of each of the bodies to create first and second electron flow paths. The voltage across each flow path is monitored. A difference in voltage of flow path relative to the other indicates a change in velocity in a direction wherein one leg leads the other leg. The voltage change correlates to acceleration. By timing the duration, velocity and distance travelled are computed. When mounted aboard a plane, vehicle, ship or spacecraft the unit displays a continous "present location".

Abstract: An improved scheme for predicting vehicle velocity independent of wheel speed for use in a vehicle antilock braking system (31) is disclosed and includes an arrangement for measuring variations in the separation between a reference point on the vehicle (11) and the surface (17) on which the vehicle (11) is supported. This measurement is appropriately scaled to obtain a signal indicative of vehicle deceleration and is integrated to obtain a signal indicative of vehicle velocity. The reference point may be a fixed location on the vehicle frame and the measuring arrangement may preferably determine variations in the spacing between the fixed point and the front axle. In the disclosed form, the measuring arrangement comprises a resistor the resistance of which varies as the spacing varies. This resistance may comprise a string potentiometer (39) fixed to the fixed point and having a lead wire (43) fastened to a lever arm (45) on the sway bar (47) of the vehicle front end suspension.

Abstract: A method and apparatus for determining a change in velocity of a body following a power disruptive event. An accelerometer (10, 50) includes quartz crystals (16 and 18, 60 and 62), which produce output signals indicative of the acceleration to which a body connected to the accelerometer is subjected. The acceleration measured is directed along the sensitive axis of the accelerometer. The quartz crystals are selected to have different scale factors, K.sub.1 and K.sub.2, which define the change in frequency of the quartz crystal from its no-load resonant frequency as a force is applied to it. The quartz crystals are connected between a supporting case (14) and a proof mass (12) so that a given acceleration applied to the proof mass along its sensitive axis causes one of the crystals to experience a tension force and the other to experience a compression force.

Abstract: A double integrating silicon acceleration sensing device which is solid state and micromachined measures the acceleration of an object and determines the distance travelled by that object through its trajectory. The device comprises a hermetically sealed container. The cavity within the container is divided by a flexible silicon diaphragm into two separate cavities, one shallow and the other deep. The two cavities are filled with a fluid which is relatively incompressible over the range of operating pressure. The fluid can only transfer between the two cavities through an orifice. Two capacitor plates form a capacitor within the shallow cavity. One of the plates is secured to a central portion of the diaphragm, and the other plate is secured adjacent to and opposite of the first plate within the shallow cavity. When the accelerometer is at rest, the two plates are separated by a given distance X.sub.g.

Abstract: An angular rate instrument adapted for mounting to a given object for measuring the rate of turn of the latter is disclosed herein. This instrument utilizes an angular accelerometer to sense angular acceleration to which the instrument is subjected and a circuit for integrating the difference between this signal and a reference signal to produce an integrated output signal corresponding to the rate of turn of the object. The angular rate instrument also utilizes a null circuit for producing the reference signal in response to and dependent on low frequency error signals which appear at the output of the signal integrating circuit. The null circuit uses a capacitor to provide the reference signal and means for maintaining the charge on the capacitor during power interruptions so as to prevent losing the reference signal as a result of such interruptions.

Abstract: The present invention is directed to an integrating angular accelerometer ich has a neutrally buoyant mass, thereby eliminating the detrimental effect of high shock and vibration loads. The accelerometer includes a housing and an inertial mass positioned in the housing, arranged for relative rotation with respect to the housing. An annular channel is provided between the housing and the inertial mass, located about the acceleration sensitive axis and dimensioned to cause fluid flow upon relative rotation of the housing and inertial mass in the direction of relative rotation. The fluid contained within the channel is a viscous fluid having a density equal to that of the inertial mass so as to achieve a neutral buoyancy of the inertial mass. A splitter for blocking fluid flow in the channel is provided so as to produce a differential pressure which corresponds to the relative angular rotation of the inertial mass and housing.

Abstract: Precision incremental-output integrator of the type comprising: an operational amplifier mounted as analog summing integrator, which sums currents I.sub.1 and I.sub.2 at the integrator input, characterized by the fact that current I.sub.2 is obtained by the discharge of a capacitor C.sub.2 and that the symmetrical reference voltage generator (Vr-), (Vr+) is replaced by a simple voltage generator (Vr) and incremental-output servosensors resulting from utilization of the said precision incremental-output integrator in which the measured magnitude, originally electrical, becomes a physical magnitude, evidenced by an electromechanical force generator by the fact that the analog amplifier of the precision incremental-output integrator (terminals A-S, FIG. 2) is replaced by the force generator of the servosensor (FIG. 3), the return current of which is current I.sub.2 discharged from capacitor C.sub.2.

Abstract: According to the invention, an accelerometer (G) is attached on the spring suspension (U) of the wheel (H) in question and capable upon passing of the vehicle over road irregularities to emit a decaying A.C. signal (S) with information on the oscillations of the axle (A) and the damping of the tire. After integration in an integrator (I) the signal is a measure of the difference between the damping of the shock absorber at expansion and at compression. This signal is compared in a comparator (K) with a reference signal (V.sub.ref) for the permissible damping difference and results in alarm (L) upon achieving said difference.

Abstract: A crash force sensor is disclosed which may be used to activate emergency location systems such as a transmitter or an inflatable aerial tethered balloon. The crash force sensor comprises a casing and a moveable seismic mass held within the casing. A plurality of friction pads and friction plates surround the mass in order to increase friction between the mass and the casing while allowing the mass the slide through said casing when a force of predetermined magnitude and direction is experienced. A pressure responsive means such as a spring extends between the mass and one end of the casing, and signal means is coupled to the mass to provide an indication of the pattern of force experienced by the sensor. The sensor may also include air damping means to impede the reaction of the mass to spring force after crash acceleration or deceleration has ceased.

Abstract: There is disclosed an apparatus for monitoring acceleration of a body which utilizes liquid flow technology thus avoiding the need for electrical power. The apparatus includes steel balls of predetermined mass (hereafter "proof masses") disposed in annular cavities of a casing, the cavities containing a damping fluid. The cavities are grouped in pairs, each pair aligned with a principal axis of the body. The pairing allows for detection of acceleration in opposite directions along the respective axis.Movement of the proof masses in these respective cavities is proportional to the time integral of acceleration along the corresponding axis. This movement develops a force which opens a check valve arrangement allowing for displacement of the fluid through a temperature compensating mechanism to a first piston-chamber arrangement which registers the total movement of all such proof masses. Fluid is returned to the cavity by a second path connected between the cavity and the chamber.

Abstract: An angular accelerometer incorporates two tilt sensors both connected to a differential amplifier arranged to provide a difference signal which is fed to a first integrator the output of which is fed to a second integrator. The tilt sensors are of the torque balance type. The tilt sensors are spaced from one another in a direction transverse to the direction along which the angular acceleration movement takes place.

Abstract: A rate measuring system for providing velocity signals, as desired, and displacement signals, including at least one accelerometer for providing an output voltage proportional to an acceleration input, amplifying means having an adjustable voltage gain for amplifying the output voltage from the accelerometer, means for integrating the amplifier output voltage to provide an output voltage proportional to velocity, means for comparing the output voltage proportional to the acceleration input and the output voltage proportional to velocity with predetermined voltage reference levels to provide an output signal when these signals are nominally zero, and means for shorting out the integrating means in response to a signal from the comparison means to provide a nominal zero velocity output.

Abstract: An integrating angular accelerometer for measuring angular rate of a rotating body has a stationary cylindrical inertial mass supported by a low drag hydrostatic bearing concentrically in a housing rotatable relative thereto and filled with a viscous fluid. An annular channel of laminar dimensions is formed between the inertial mass and housing and a vane is arranged in the channel to block fluid flow caused by rotation of the housing relative to the inertial mass. The differential pressure in the channel at opposite sides of the vane provides a signal corresponding to the rate of rotation of the housing relative to the inertial mass.

Abstract: A force rebalanced accelerometer utilizing a spherical proof mass disposed in a fluid and in which fluid pressure pulses developed by positive displacement pump are used to balance inertial forces.

Abstract: A velocity sensor which may be modified to perform a sensing function for either angular velocity or linear velocity. The sensor has a base member which is split into upper and lower halves which are shaped to form internal walls defining an internal channel when joined together. A fluid is disposed in the internal channel and a paddle member is placed in communication with the fluid. Sensing means are present to detect the position of the paddle member as it is urged into motion by the inertia of the fluid mass in the angular embodiment and by the inertia of the paddle member in the linear. An electrical output is provided which is related to the urge to move imparted to the paddle member. The output is used to electrically restrain the motion of the paddle member. The output related to paddle member motion is also integrated to provide a signal related to velocity. Saturation of the integrated output unrelated to velocity is prevented by additional electrical means.