Abstract: An inertial sensor includes a substrate, a first supporting beam being a first rotation axis extending along a first direction, a first movable member swingable around the first rotation axis, a second supporting beam being a second rotation axis extending along a second direction crossing the first direction, a second movable member swingable around the second rotation axis, a third rotation axis extending along a second direction, a third movable member swingable around the third rotation axis, and a projection, wherein the second and third movable members are line-symmetrically placed with a center line of the first movable member along the second direction as an axis of symmetry, a center of gravity of the second movable member is closer to the center line than the second supporting beam, and a center of gravity of the third movable member is closer to the center line than the third supporting beam.

Abstract: This disclosure is related to devices, systems, and techniques for determining an acceleration. For example, an accelerometer system includes a resonator and a light-emitting device configured to generate, based on an error signal, an optical signal. Additionally, the accelerometer includes a modulator configured to receive the optical signal, generate a modulated optical signal responsive to receiving the optical signal, and output the modulated optical signal to the resonator. A photoreceiver receives a passed optical signal from the resonator, where the passed optical signal indicates a resonance frequency of the resonator. Additionally, the photoreceiver receives a reflected optical signal from the resonator. The photoreceiver generates one or more electrical signals based on the passed optical signal and the reflected optical signal. Processing circuitry generates the error signal and determines the acceleration based on the one or more electrical signals.

Abstract: An acceleration sensor includes a substrate, a first movable body that includes a first movable portion and a second movable portion having a rotational moment around a first swinging axis smaller than that of the first movable portion, a second movable body that includes a third movable portion and a fourth movable portion having a rotational moment around a second swinging axis smaller than that of the third movable portion, a first fixed electrode that is disposed on the substrate and faces the first movable portion, a second fixed electrode that faces the second movable portion, a third fixed electrode that faces the third movable portion, a fourth fixed electrode that faces the fourth movable portion, and a coupling portion that couples the first movable body and the second movable body.

Abstract: A wheel speed detection device according to one aspect of the present disclosure is installable on a wheel bearing which comprises an outer ring and an inner ring coupled to a rotating shaft and relatively rotated relative to the outer ring about the rotating shaft. The wheel speed detection device comprises a first target concentrically coupled to the rotating shaft, a second target disposed along an outer circumference of the inner ring, a cap coupled to the outer ring to cover the first target and the second target, a first sensor disposed in the cap and configured to detect a variation in magnetic field of the first target due to a rotation of the rotating shaft, and a second sensor disposed in the cap and configured to detect a variation in magnetic pole of the second target due to a rotation of the inner ring.

Abstract: A method may comprise obtaining, during drilling operations within a wellbore, two-dimensional accelerometer data with an accelerometer on a rotating downhole tool, determining a radial offset of the accelerometer based on the two-dimensional accelerometer data, and determining a centripetal acceleration of the accelerometer based on the two-dimensional accelerometer data. A system may comprise one or more x-axis accelerometers disposed on a bottom hole assembly, one or more y-axis accelerometers disposed on the bottom hole assembly, an analog to digital converter, wherein the analog to digital converter converts an analog signal from the one or more x-axis accelerometers and the one or more y-axis accelerometers to a digital signal, and a computing subsystem.

Abstract: A rotation angle encoder apparatus is disclosed. The rotation angle encoder apparatus may comprise a plurality of light sources, a plurality of light detectors, and a plurality of pinions rotatable about a shaft. Each of the pinions may comprises a plurality of teeth and a plurality of gaps. The rotation angle encoder apparatus may comprise a plurality of stacked configurations such that, when the shaft is rotated, transmissivity may be measured to determine or calculate at least one measurement, such as an angle of rotation, position, movement, distance, or other discernable measurement. The rotation angle encoder apparatus with a plurality pinions and associated measurable transmissivities may enable an optical spectrum analyzer to increase wavelength accuracy and improve resolution in optical measurements.

Abstract: The invention relates to a field device of measuring and automation technology. The field device has a radio module for providing access to an operating electronics of the field device. Such access enables the exchange of information between the operating electronics and a user. The radio module can be turned on by a first input signal sequence composed of accelerations of the field device housing and can be turned off by a second input signal sequence. A field device of the invention is shown schematically in FIG. 1.

Abstract: Provided are acceleration sensor, geophone and seismic prospecting system with high sensitivity and low power consumption. The acceleration sensor includes a mass body displaceable with respect to a rotation shaft. The acceleration sensor includes a first AC servo control facing a first symmetrical region of the first movable portion, a second AC servo control electrode facing a second symmetrical region of the second movable portion, and a DC servo control electrode facing an asymmetrical region of the second movable portion. A first AC servo capacitive element is formed by the first movable portion and the first AC servo control electrode, a second AC servo capacitive element is formed by the second movable portion and the second AC servo control electrode, and a DC servo capacitive element is formed by the second movable portion and the DC servo control electrode.

Abstract: A system is disclosed for suspension of a mobile mass, such as an inertial angular sensor, including a connection device including first and second connection elements connected to each other through a connection block and deformable in bending in a mobility plane so as to enable displacements relative to the connection block, of the mobile mass connected to the first connection element, and of another element of the system connected to the second connection element such as a support or another mobile mass respectively, along two distinct directions respectively. At least one of the connection elements is formed from two springs, connecting the connection block to the mobile mass or the other element of the system respectively. The connection element thus has improved linearity properties.

Abstract: A magnetic angular sensing system has a magnet magnetized radially and a magnetic angular sensor for sensing the angular position of the magnet. The magnetic angular sensor is mounted in parallel to the axis of the magnet and is non-coplanar with the magnet. The magnetic angular sensor senses an angular position of the magnet based on a detected axial magnetic field component and a tangential magnetic field component of the magnetic field vector where the sensor mounted. This invention provides a flexible sensing system.

Abstract: The present disclosure relates to an apparatus comprising at least one sensing capacitor and a controller, wherein the controller is configured to receive a signal from the at least one sensing capacitor indicative of a change of charge of the sensing capacitor, and wherein the controller is configured to determine an amount of force applied to the sensing capacitor, an acceleration of the sensing capacitor, a torsion of the sensing capacitor, a vibration of the sensing capacitor or a pulling force applied to the sensing capacitor based on the change of charge of the at least one sensing capacitor.

Abstract: A portable powered roller assembly configured to impart a motive force to a wheeled vehicle or structure consists of a roller mounted in a rolling support structure. The roller is rotationally driven by a battery-powered drive unit coupled through a torque multiplying transmission, and is configured for engagement with the circumferential surface of a vehicle wheel. Rotational movement of the roller in engagement with the circumferential surface of the vehicle wheel draws the powered roller assembly towards, and under, the curved circumferential surface of the vehicle wheel, imparting a force to the vehicle wheel which include both a lifting force perpendicular to the supporting surface on which the powered roller is resting, and a motive force parallel to the surface.

Abstract: Automatic turn-sensing ground speed reduction systems and related methods for walk-behind, self-propelled machines are disclosed. In one aspect, automatic turn-sensing ground speed reduction systems and related methods can include a control unit and a sensor. The sensor can be configured to transmit a signal to the control unit. In some aspects, the sensor can include a gyroscope that can be configured to transmit the signal to the control unit, the signal corresponding to an angular velocity of the walk-behind machine measured about a vertical axis perpendicular to a ground surface on which the walk-behind machine can be self-propelled. The control unit can be configured to automatically adjust a ground speed of the walk-behind machine during turning movement of the walk-behind machine based upon the signal.

Abstract: An apparatus includes an image recorder configured to record video images. The apparatus also includes a display screen configured to present the video images to a user and to create notations overlying one or more of the video images based on user input. The apparatus further includes a transceiver configured to stream the video images over a wireless mesh network and to transmit data associated with the notations over the wireless mesh network. The apparatus could also include components for providing cryptographic keys to wireless nodes joining the wireless mesh network, a sensor for detecting or measuring one or more characteristics, and/or an asset tracker for transmitting or receive signals for identifying a location of the apparatus. The apparatus could further include at least one voice unit supporting bidirectional voice communications and/or a site survey unit for identifying signal strengths associated with detected wireless nodes.

Abstract: An accelerometer is provided having a power circuit, a detection circuit, and a compensation circuit. The compensation circuit is operative to measure an offset voltage occurring between an output reference voltage from the power circuit and an output voltage from the detection circuit state, store the offset voltage during a zero acceleration, and output the stored offset voltage to alter the output voltage of the detection circuit.

Abstract: A physical quantity sensor includes a first rocking body and a second rocking body. Each of the rocking bodies is supported on a substrate by a first supporting portion and a second supporting portion. The first rocking body is partitioned into a first region and a second region by a first axis (supporting axis) when viewed in plane, and the second rocking body is partitioned into a third region and a fourth region by a second axis (supporting axis) when viewed in plane. The mass of the second region is larger than the mass of the first region, and the mass of the third region is larger than the mass of the fourth region. An arranged direction of the first region and the second region is the same as an arranged direction of the third region and the fourth region.

Abstract: A system and method for safing vehicle sensors includes two safety systems, each with a primary sensor for monitoring vehicle motion and activating its corresponding safety system in response to certain vehicle motions. Each sensor may act as a safing sensor for the other in the event that activation of a safety system is indicated by the primary sensor. Each sensor may also monitor the other prior to such an event, to detect a sensor malfunction before that sensor is needed to active a safety system.

Abstract: A personal mobile device housing contains a display screen, a wireless telephony communications transceiver, and a battery charger interface. A temperature sensor and a gyro sensor whose zero turn rate output contains an offset are also included. A lookup table has gyro zero turn rate offset correction values associated with different temperature values. A programmed processor accesses the lookup table to correct the output of the gyro sensor for zero turn rate offset. It is automatically determined, during in-the-field use, when the device is in a motionless state, and the output of the temperature and gyro sensors are read. The read gyro output is written to the lookup table as part of a pair of associated temperature and zero turn rate offset correction values. Other embodiments are also described and claimed.

Abstract: A control system for use in safety critical human/machine control interfaces is described, more particularly a joystick type control system and particularly a joystick type control system utilizing magnetic positional sensing. The control system provides a control input device having a movable magnet, a pole-piece frame arrangement positioned about the magnet, at least three magnetic flux sensors being positioned in said pole-piece frame arrangement and a monitoring arrangement for monitoring the output signal of each of said at least three sensors.

Abstract: The present embodiments provide an acceleration sensor, which enables highly accurate detection and has an extremely compact size. The acceleration sensor of the present embodiments is provided with a substrate, a anchor portion formed on the substrate, a support beam, which has one end connected to the anchor portion and extends across a space from the substrate, and a proof mass which is connected to the other end of the support beam and held across a space from the substrate. The acceleration sensor is further provided with first and second piezoelectric bending resonators, a comparison unit, and a calculation unit. The first and second piezoelectric bending resonators have one end connected to the anchor portion and the other end connected to the proof mass or the support beam and have a stack of a first electrode, a first piezoelectric film, and a second electrode.

Abstract: An acceleration sensor includes a substrate, first and second torsion beams, first and second detection frames, first and second detection electrodes, first and second link beams, and an inertial mass body. The first and second torsion beams are distorted around the first and second torsion axes. The first and second detection frames are rotated about the first and second torsion axes. The first and second detection electrodes detect an angle formed between the substrate and each of the first and second detection frames. The first link beam is on a first axis located at a position shifted from a position of the first torsion axis to one end side of the first detection frame along a direction crossing the first torsion axis. The second link beam is on a second axis located at a position shifted from a position of the second torsion axis in a direction identical to the direction of shift from the position of the first torsion axis.

Abstract: A device for determining the rotational speed of a transmission shaft (12). The device includes a rotational speed indicator (3) connected, in a rotationally fixed manner, to the transmission shaft (12) and at least one rotation speed sensor (2) including at least one sensor element (10). By way of the sensor element (10), the speed of the transmission shaft (12) is detected via the speed indicator (3). The speed sensor (2) is attached to a shifting element (5) for actuating a sliding sleeve (4) of a clutch device (1) that is connected to the transmission shaft (12) in such a manner that the sliding sleeve (4) axially movable on but fixed so as not to rotate.

Abstract: An electronic device and method to prevent falling of the electronic device include setting one or more alarm means, detecting an acceleration and a moving direction of the electronic device using the three-axis accelerometer, and detecting that the electronic device is in a falling state if the acceleration is larger or equal to the acceleration of gravity and the moving direction is in the gravitational direction. The electronic device and method further include activating one or more of the alarm means if the electronic device is in the falling state or if a clip connected with a strap of the electronic device is not in a tightened state.

Abstract: A method of determining at least one rotation parameter of a wind turbine rotor rotating with a rotation speed and a phase is provided. The method includes: measuring an effective centrifugal force acting in a first pre-determined direction, which is defined in a co-ordinate system rotating synchronously with the rotor, on at least one reference object located in or at the rotor, establishing a first angular frequency representing the rotation speed of the rotor on the basis of variations in the measured effective centrifugal force due to gravitational force, establishing a second angular frequency representing the rotation speed of the rotor by use of at least one yaw rate gyro, and establishing the value of the rotation speed as the rotational parameter by correcting the second angular frequency by comparing it to the first angular frequency.

Abstract: An accelerometer is provided having a power circuit, a detection circuit, and a compensation circuit. The compensation circuit is operative to measure an offset voltage occurring between an output reference voltage from the power circuit and an output voltage from the detection circuit state, store the offset voltage during a zero acceleration, and output the stored offset voltage to alter the output voltage of the detection circuit.

Abstract: An angular position sensor and method that relies on a stationary circular array of Hall sensors and a rotatable circular array of magnets arranged about a common axis. A periodic and simultaneous reading of all of the Hall sensor outputs is used to determine angular velocity.

Abstract: A control device for a travel motor mounted to a vehicle has a resolver which works as a rotation-angle sensor. The control device has a RDC which calculates a rotation-angle output value ? based on rotation detection signals Sa, Sb transferred from the resolver. The control device supplies electric power to the travel motor based on the rotation angle output value ?. The RDC calculates “sin(???)” as an error deviation ? based on the signals Sa and Sb and the rotation-angle output value ?. The RDC calculates an angular acceleration by multiplying the error deviation ? with a gain (=Ka·Kb), and integrates the angular acceleration two times in order to obtain a next rotation-angle output value. A gain control part of the RDC decreases the gain when the judgment means judges that the travel motor rotates at a constant rotation speed.

Abstract: Disclosed are apparatus and methodologies for detecting inversion tamper, removal tamper, and taps using a three-axes accelerometer sensor in a utility meter environment. Inversion tamper is detected upon power up if the acceleration value along Y axis is greater than or equal to some small positive threshold. Removal tamper is detected if the average acceleration change of both Y and Z axes is greater than or equal to the removal threshold. A tap is detected if the average acceleration change along the X axis is greater than or equal to the tap threshold. The initial acceleration values are set upon power up. Removal tamper detection and tap detection are distinguished using a moving average filter. Tap detection uses timing constraints to avoid false tap detections.

Abstract: A physical quantity sensor includes a first rocking body and a second rocking body. Each of the rocking bodies is supported on a substrate by a first supporting portion and a second supporting portion. The first rocking body is partitioned into a first region and a second region by a first axis (supporting axis) when viewed in plane, and the second rocking body is partitioned into a third region and a fourth region by a second axis (supporting axis) when viewed in plane. The mass of the second region is larger than the mass of the first region, and the mass of the third region is larger than the mass of the fourth region. An arranged direction of the first region and the second region is the same as an arranged direction of the third region and the fourth region.

Abstract: The present embodiments provide an acceleration sensor, which enables highly accurate detection and has an extremely compact size. The acceleration sensor of the present embodiments is provided with a substrate, a anchor portion formed on the substrate, a support beam, which has one end connected to the anchor portion and extends across a space from the substrate, and a proof mass which is connected to the other end of the support beam and held across a space from the substrate. The acceleration sensor is further provided with first and second piezoelectric bending resonators, a comparison unit, and a calculation unit. The first and second piezoelectric bending resonators have one end connected to the anchor portion and the other end connected to the proof mass or the support beam and have a stack of a first electrode, a first piezoelectric film, and a second electrode.

Abstract: An accelerometer with improved immunity to sensitivity drift is disclosed. In some embodiments, the accelerometer comprises an actuator that induces a known acceleration on a reference frame. A signal based on this known acceleration is used to calibrate the accelerometer to mitigate the effects due to at least one of sensitivity drift, D.C. bias drift, sense laser wavelength drift, and resonant frequency drift.

Abstract: In a method for ascertaining a rotational direction of a rotating body, one rotational direction and one rotational speed value which indicates the rotational frequency of the rotating body are ascertained in each of multiple measurements. The rotational speed values of the multiple measurements are compared to each other, and a rotational direction of the rotating body is ascertained from the measured rotational directions and the comparison of the rotational speed values.

Abstract: An acceleration sensor includes a substrate, first and second torsion beams, first and second detection frames, first and second detection electrodes, first and second link beams, and an inertial mass body. The first and second torsion beams are distorted around the first and second torsion axes. The first and second detection frames are rotated about the first and second torsion axes. The first and second detection electrodes detect an angle formed between the substrate and each of the first and second detection frames. The first link beam is on a first axis located at a position shifted from a position of the first torsion axis to one end side of the first detection frame along a direction crossing the first torsion axis. The second link beam is on a second axis located at a position shifted from a position of the second torsion axis in a direction identical to the direction of shift from the position of the first torsion axis.

Abstract: A method and apparatus for calibrating wheel speed signals measured by wheel rpm sensors in a vehicle equipped with at least one longitudinal acceleration sensor integrates the signal of the longitudinal acceleration sensor during the acceleration or deceleration phases of the vehicle, and the resulting vehicle speed signal is compared against the signals of the individual wheel rpm sensors. A determination is made as to whether a deviation that may exist for a wheel lies within a predefined tolerance range. If a deviation falls outside of the tolerance range, the parameterized tire circumference of the associated wheel is adaptively recalibrated until the deviation falls within the tolerance range.

Abstract: A piezoelectric resonator element includes: a resonating arm extending in a first direction and cantilever-supported; a base portion cantilever-supporting the resonating arm; and an excitation electrode allowing the resonating arm to perform flexural vibration in a second direction that is orthogonal to the first direction. In the piezoelectric resonator element, the resonating arm includes an adjusting part adjusting rigidity with respect to a bend in a third direction that is orthogonal to the first and second directions.

Abstract: A movable device simultaneously enabling reduction of size down to the submicron level, higher speed operation, a streamlined production process, low costs, and greater reliability. A movable device provided with bottom electrodes and a basic conductive layer fixed to a substrate, an elastic shaft of a carbon nanotube with a bottom end fixed on the basic conductive layer and standing up, and a top structure including a top electrode spaced away from the bottom electrode and fixed to a top end of the elastic shaft, wherein when applying voltage between a bottom electrode and the top electrode, the top electrode displaces relatively to the bottom electrodes within an allowable range of elastic deformation of the elastic shaft.

Abstract: An apparatus and methods for identifying a defect and/or an operating characteristic of a system being monitored (and/or one or more of the system's components) are described. In an embodiment, orthogonally related data monitored by two or more detectors may be fused to determine whether a component of a system is defective and/or malfunctioning. Additionally or alternatively, data from a first detector may be determined to be accurate using non-orthogonally related data outputted by a second detector. Both types of determinations may be made with minimal or no false indications, which lowers the cost of operating the system being monitored.

Abstract: A sensor package apparatus includes a lead frame substrate that supports one or more electrical components, which are connected to and located on the lead frame substrate. A plurality of wire bonds are also provided, which electrically connect the electrical components to the lead frame substrate, wherein the lead frame substrate is encapsulated by a thermoset plastic to protect the plurality of wire bonds and at least one electrical component, thereby providing a sensor package apparatus comprising the lead frame substrate, the electrical component(s), and the wire bonds, while eliminating a need for a Printed Circuit Board (PCB) or a ceramic substrate in place of the lead frame substrate as a part of the sensor package apparatus. A conductive epoxy can also be provided for maintaining a connection of the electrical component(s) to the lead frame substrate. The electrical components can constitute, for example, an IC chip and/or a sensing element (e.g., a magnetoresistive component) or sense die.

Abstract: An encapsulated measuring device for detecting a velocity and/or acceleration of a rotationally or linearly moved component. The device includes a measuring device housing having a wall, and a scanning unit arranged in the housing, the scanning unit including a scanning head in the form of a Ferraris sensor, and wherein an eddy current body of the Ferraris sensor includes at least a portion of the wall of the measuring device housing.

Abstract: An energy-efficient acceleration measurement system is presented. The system includes an accelerometer, responsive to acceleration of the system, for providing an accelerometer output signal having a magnitude indicative of at least one component of the acceleration. A motion detector is responsive to the accelerometer output signal, and provides a processor interrupt signal, but only if the magnitude of acceleration reaches a threshold. The processor, responsive to the processor interrupt signal, measures the acceleration with higher accuracy than the motion detector is capable of, but in a way that consumes more power than was needed by the motion detector.

Abstract: A collision sensing apparatus includes an acceleration sensor, first and second connector terminals, reference connector terminals and leads. The acceleration sensor is shaped into a square form. First and second contacts are provided in two diagonally opposed corner portions of the sensor. Reference contacts are arranged in the other two diagonally opposed corner portions of the sensor. The first and second connector terminals are opposed to the first and second contacts, respectively. The reference connector terminals are opposed to the reference contacts, respectively. The leads connect the first and second connector terminals and the reference connector terminals to the first and second contacts and the reference contacts.

Abstract: A color contour of an object is displayed from information that is obtained using an array of thermopile sensors. A color contour of an object is generated by pre-establishing a relationship between IR radiation power and color, measuring the power of incident IR radiation emanating from different locations on the object, mapping the measured IR radiation powers to colors, and generating color contour information that can be displayed on a color display. The color contour information represents the temperature of an object at different locations.

Abstract: A sensor unit is supported on a stationary ring which does not rotate even when it is in use, and the rotation of the rotary ring can be detected by a rotation detecting sensor held within the sensor unit. Within the sensor unit, besides the rotation detecting sensor, there are disposed other sensors such as a temperature sensor and a vibration sensor, thereby being able to detect the rotation speed and the rotation number of the wheel supported on the rotary ring, and the other car driving conditions.

Abstract: A wheel rotation detecting device including a sensor unit that is supported on a stationary ring which does not rotate even when the wheel is in use, and the rotation of the wheel that is attached to a rotary ring can be detected by a rotation detecting sensor held within the sensor unit. Within the sensor unit, in addition to a rotation detecting sensor, there are disposed other sensors such as a temperature sensor and a vibration sensor, thereby allowing detection of the rotation speed and the rotation number of the wheel supported on the rotary ring, as well as detection of other car driving conditions.

Abstract: A Micro Electro-Mechanical System (MEMS) acceleration sensing device, formed of a sensing element having first and second substantially planar and parallel spaced apart opposing surfaces and being suspended for pendulous motion about a hinge axis oriented along a minor axis of the sensing element; and one or more substrates each having a face spaced from one of the opposing surfaces of the sensing element, each of the substrates having pluralities of electrodes arranged substantially crosswise to the hinge axis of the sensing element symmetrically to a longitudinal axis of the sensing device and forming respective first and second capacitors with the moveable sensing element. Each of the one or more substrates optionally including a clearance relief for extending the rotational range of motion of the sensing element.

Abstract: A Ferraris sensor for measuring an acceleration of a moving body along a direction. The sensor includes a flat eddy current body and a scanning head arranged on one side of the eddy current body. The scanning head includes N magnets that generate an external magnetic field that extends approximately perpendicular to a surface of the eddy current body, wherein N=1, 2, 3, . . . and M detector coils, wherein M=1, 2, 3, 4, . . . and each detector coil includes an axis and detects changes of an interior magnetic field within the N magnets that are caused by an acceleration of the eddy current body and a resulting change in eddy currents. The axis is approximately perpendicular with respect to the surface of the eddy current body, each detector coil lacks a ferromagnetic core and the N magnets and the M detector coils are arranged alternatingly next to each other in a direction that the acceleration is to be measured.

Abstract: A speed sensor for a marine vessel includes a correction circuit to correct any sensor non-linearities so that the sensor produces an output with a pulse stream having a constant pulse rate, and reduces the pulse-to-pulse variations of the pulse stream. The circuit can standardize the pulse stream to have a frequency corresponding to a standard rate.

Abstract: A method for determining the mass moment of inertia of an electric motor drive system of a machine, having a drive motor and further drive elements arranged downstream of the drive motor. The method includes a) determining a compensation current, which compensates losses occurring at a constant speed of the motor, so that a motor speed of the drive motor remains constant and b) determining an acceleration current, which generates a defined acceleration of the drive motor when the losses occurring at the constant speed of the drive motor are compensated. The method further entails c) calculating a mass moment of inertia of the electric motor drive system based on the determined acceleration current.

Abstract: There is described a method for determining the speed of a wheel on a motor vehicle, for which purpose an acceleration sensor is mounted on the wheel. It is proposed according to the invention to measure the frequency &ohgr; or the period T of an alternating signal contained in the acceleration signal supplied by the acceleration sensor and produced by the influence of gravitational acceleration g. The method is suited for use in automatic tyre-pressure monitoring systems for assigning signals, that have been transmitted by radio from a wheel-mounted electronic module, to a particular wheel position and for controlling the transmission rate of a wheel-mounted electronic module as a function of the speed.

Abstract: An eddy current sensor including an arrangement for generating a first magenetic flux, which is essentially directed vertically with respect to a moved body, a detector coil for detecting an eddy field in the moved body and a second arrangement which generates a further adjustable magnetic flux, which is superimposed on the first magnetic flux to form a resultant magnetic flux.