Abstract: The invention relates to an angular velocity sensor used in posture control of a moving element or navigation system, and is intended to realize higher sensitivity, lower offset, lower offset drift, lower translation acceleration sensitivity, and higher impact resistance in a small size and at low cost.

Abstract: An acoustic impedance measuring apparatus emits ultrasonic waves to a target measurement object and measures the acoustic impedance of the target measurement object by ultrasonic waves fed back from the target measurement object. This acoustic impedance measuring apparatus includes an ultrasonic transducer, pulse signal generator, signal separator, frequency converter, parameter extractor, and acoustic impedance calculator. The pulse signal generator generates a pulse signal to be applied to the ultrasonic transducer. The signal separator separates, from an output from the ultrasonic transducer, an immediate ultrasonic response signal resulting from ultrasonic waves reflected by the surface of the target measurement object. The frequency converter obtains the frequency characteristics of the immediate ultrasonic response signal. The parameter extractor extracts predetermined parameters from the frequency characteristics.

Abstract: An apparatus for determining a physical process variable of a medium (2) which can be used in conjunction with various sensor types, the sensors having in common that they determine a process variable by means of a delay-time method. The apparatus has a sensor (4), a sensor-specific application unit (5) and an evaluation unit (6), which is essentially independent of the sensor type used, the sensor (4) being assigned a transmitting/receiving unit (7), the transmitting unit (7a) transmitting measuring signals in the direction of the medium (2) and the receiving unit (7b) receiving the measuring signals influenced by the interaction with the medium (2), and the application unit (5) being designed in such a way that it provides measurement data, independently of the type of sensor (4) used, from which the evaluation unit (6) determines the physical process variable using a delay-time method by means of a uniform evaluation algorithm.

Abstract: A wheel balancing system for the reduction of vehicle wheel and pneumatic tire assembly vibrations with the capacity to determine and selectively adjust the pneumatic tire's pressure simultaneously with wheel balancing. The balancing system includes a drive for rotating the tire and wheel assembly; a sensing system for the selective determination of vibration causation and correction information; a pneumatic system for the adjustment of the pneumatic tire's pressure; a control system for instituting the determined vibration corrections and pressure adjustments; as well as a communication system for receiving, transmitting and presenting data or instructions. The sensing system is responsive to the wheel balancing systems operational status, the wheel and tire assembly's operational status, wireless or network communications and input from the user. The control system includes automatic provisions for safety, convenience, time efficiency, balancing and pressure adjustment.

Abstract: A method and apparatus for monitoring one or more parameters of a variable physical structure, such as liquid level, is disclosed. The method and apparatus includes an electrodynamic element placed in proximity to a monitored structure and exciting within said element an alternating electromagnetic field. The electromagnetic field should be at a frequency at which the electromagnetic field penetrates into the monitored structure and then variations of the electromagnetic field parameters are measured for the element caused by a variation in the structure. The exciting of the electrodynamic element is by an electromagnetic field in the form of at least one slowed electromagnetic wave having suitable energy distribution of the electric and magnetic fields for the measuring of the electromagnetic field parameters.

Abstract: A flexure transducer element used in an acceleration sensor for sensing an acceleration applied thereto and the method of making the same. The flexure transducer element comprises a frame, a sheet member, a weight, and a support member.

Abstract: A diagnostic system includes a vibration sensor mounted on a machine to measure vibrations. Vibration signals from the sensor are processed and analyzed by the system. From a known critical frequency of a vibration-generating component, the system measures the amplitude of the vibration signal at more than one harmonic frequency of the known critical frequency and compares the amplitudes to amplitudes at adjacent harmonic frequencies. When a relatively large amplitude is found at a harmonic frequency, that is a harmonic frequency near a resonant frequency of the physical path between the vibration sensor and the vibration-generating component, the system analyzes the shape and magnitude of the vibration signal around that harmonic frequency to evaluate the condition of the machine.

Abstract: A high sensitivity, Z-axis, capacitive microaccelerometer having stiff sense/feedback electrodes and a method of its manufacture on a single-side of a semiconductor wafer are provided. The microaccelerometer is manufactured out of a single silicon wafer and has a silicon-wafer-thick proof mass, small and controllable damping, large capacitance variation and can be operated in a force-rebalanced control loop. One of the electrodes moves with the proof mass relative to the other electrode which is fixed. The multiple, stiffened electrodes have embedded therein damping holes to facilitate force-rebalanced operation of the device and to control the damping factor. Using the whole silicon wafer to form the thick large proof mass and using thin sacrificial layers to form narrow uniform capacitor air gaps over large areas provide large capacitance sensitivity. The manufacturing process is simple and thus results in low cost and high yield manufacturing.

Abstract: The invention concerns a monitor head for ultrasound control by pulse echo process, in particular for producing a brief ultrasound pulse, unipolar as far as possible, comprising an oscillator/transmitter (26) and an oscillator/receiver (32), each provided with electrodes (28, 30, 34, 36). The oscillator/transmitter (26) and the oscillator/receiver (32) are made of the same material. The oscillator/transmitter (26) and the oscillator/receiver (32) are arranged directly one behind the other, in the sound propagation direction, in particular flat-bonded one on the other.

Abstract: The invention is based on a system for changing a signal representing rotational motion in a motor vehicle with first means for generating a first signal representing the rotational motion and a second means for generating at least one second signal representing additional information (direction of rotation, air gap, and/or brake lining wear). In addition, a third means is provided, by means of which the first signal (rotational speed signal) can be changed as a function of the second signal (direction of rotation, air gap, and/or brake lining wear). The essence of the invention is that the first means is designed in such a way that the first signal (rotational speed signal) assumes at least two first current values and/or two first voltage values.

Abstract: A rotary accelerometer having a nonrotatable cylindrical magnet return path formed out of magnetic permeable material. One or more permanent magnets, with two opposite poles, are disposed around the magnetic return path. An electrically conductive cup with an access for rotation therearound in which the cup surrounds the permanent magnets and the permanent magnets are arranged so as to produce a magnetic field through the cup into the nonrotatable cylindrical magnet return path, thereby inducing eddy currents inside the cup when rotating in the magnetic field. A stator core is formed out of magnetic permeable material surrounding the cup and nonrotatable relative thereto, the stator core having at least two pickup members. The stator is formed from at least one continuous piece of magnetic permeable material. One or more stator windings are disposed on to the pickup members of the stator core for sensing changes in a secondary magnetic field generated by the eddy currents in the cup.

Abstract: A method and system for detecting an imbalance condition in a rotating washing machine tub includes receiving an indication of the actual tub rotation speed, comparing the actual tub rotation speed to a predetermined desired rotation speed to calculate a speed error, and determining maximum and minimum speed errors. The difference between the maximum and minimum speed error is calculated, and a tub imbalance condition is detected based at least in part on the calculated difference. In one embodiment, the speed error is input to a controller that produces an output used to minimize the absolute speed error. The difference between the minimum and maximum controller output is then used to determine tub imbalance. In another aspect of the invention, the method and system include receiving an indication of a power level required to achieve a given washing machine rotation speed and comparing the required power level to a predefined standard power level associated with the given rotation speed.

Abstract: A micromachined device is provided that establishes select dimensional relationships between micromachined structures to achieve correlation in dimensional variation among these structures.

Abstract: A drive circuit supplies a FB feedback signal having a predetermined frequency to drive electrodes to vibrate a vibrator. An angular velocity detecting circuit detects a vibratory movement caused in a direction normal to an oscillating direction of the vibrator based on a sensing signal of angular velocity sensing electrodes, thereby generating an angular velocity signal. A signal input circuit supplies a diagnostic signal having a frequency different from that of the FB signal, which is entered into the vibrator via diagnosing electrodes. A diagnosis circuit generates a breakdown signal based on a signal responsive to the diagnostic signal which is obtained from at least one of the drive electrodes and the angular velocity sensing electrodes.

Abstract: A flexible substrate (110) having flexibility and a fixed substrate (120) disposed so as to oppose it are supported at their peripheral portions by a sensor casing (140). An oscillator (130) is fixed on the lower surface of the flexible substrate. Five lower electrode layers (F1 to F5: F1 and F2 are disposed at front and back of F5) are formed on the upper surface of the flexible substrate. Five upper electrode layers (E1 to E5) are formed on the lower surface of the fixed substrate so as to oppose the lower electrodes. In the case of detecting an angular velocity &ohgr; x about the X-axis, an a.c. voltage is applied across a predetermined pair of opposite electrode layers (E5, F5) to allow the oscillator to undergo oscillation Uz in the Z-axis direction. Thus, a Coriolis force Fy proportional to the angular velocity &ohgr;x is applied to the oscillator in the Y-axis. By this Coriolis force Fy, the oscillator is caused to undergo displacement in the Y-axis direction.

Abstract: An EMAT device for non-destructive inspection of the surface of a tube for cracks using acoustic surface waves includes a pulsed magnet having an active surface for facing the surface of a tube to be inspected. A receive emat coil is on the active surface and a transmit emat coil is on the opposite surface of the receive coil. The transmit emat coil has a scan surface for scanning over the tube surface. A transmitter for generating and transmitting an RF signal to the transmit emat coil is provided for generating a transmitted acoustic wave signal along the tube, the transmitted wave creating a reflected acoustic wave if a crack in the tube is encountered, the reflected wave generating a reflection signal in the receive emat coil. A receiver is connected to the receive emat coil for receiving the reflection signal.

Abstract: A sensor including a center post extending along the sensing axis of the sensor, a piezoelectric sensing element concentrically engaging the center post, and a preload element preloading the piezoelectric element radially outward to the axis. The center post includes a recess along the axis and the first preload element is in the recess and preloads the piezoelectric element radially outward. The sensor may include a mass concentrically engaging the piezoelectric element. The sensor senses acceleration, force or pressure.

Abstract: An ultrasonic-wave distance measuring apparatus of the separate transmission and reception type reflection system capable of making the measurable distance longer and improving the precision of the measuring, wherein a distance measurement calculation control circuit in an ultrasonic-wave transmitter starts counting a time simultaneously with the start of vibration of an ultrasonic-wave transmission sensor, the ultrasonic-wave emitted from the ultrasonic-wave transmission sensor is reflected at the object to be measured and detected by an ultrasonic-wave reception sensor, a distance measurement sensitivity correction circuit corrects the sensitivity of the signal from the ultrasonic-wave reception sensor based on sensitivity correction data predetermined in accordance with a type of object and a measurement distance, the signal after the sensitivity correction by the distance measurement sensitivity correction circuit is detected in a detection circuit, and the distance measurement calculation control circuit

Abstract: In view of the fact that, when backup roll bearings which have been found satisfactory in the purity thereof in the sample evaluation through observations using a microscope are checked many times for the top surface layer portions of the raceway surfaces thereof according to an ultrasonic detecting method, on quite rare occasions, there can be found a bearing which contains one or more inclusions each having a size of as large as several hundreds &mgr;m, and such inclusions give rise to occurrence of a short-life bearing as a finished product, a range expressed by 2% Da depth×raceway surface is used as a test piece volume and the size of a non-metallic inclusion existing in the test piece volume is restricted to a length less than 500 &mgr;m, preferably, less than 100 &mgr;m. Here, the term “2% Da depth” means a depth up to 2% of a rolling element mean diameter from the surface of an inner or outer race of a bearing.

Abstract: A method of fabricating a micro-mechanical sensor (101) comprising the steps for forming an insulating layer (6) onto the surface of a first wafer (4) bonding a second wafer (2) to the insulating layer (6), patterning and subsequently etching either the first (4) or second wafer (6) such that channels (18, 20) are created in either the first (2) or second (4) wafer terminating adjacent the insulating layer (6) and etching the insulating layer (6) to remove portions of the insulating layer (6) below the etched wafer such that those portions of the etched wafer below a predetermined cross section, suspended portions (22), become substantially freely suspended above the un-etched wafer. This method uses Silicon on Insulator technology. Also disclosed is a micro-mechanical gyroscope structure (101) allowing an anisotropic silicon to be used to fabricate a sensor functioning as if fabricated from isotropic silicon.