Transense Technologies, Plc

Michelin Recherche Et Technique S.a.

Transence Technologies Plc

Victor Alexandrovich Kalinin

John Peter Beckley

Arthur John Leigh

Raymond David Lohr

Mark Lee

Bryn James Dixon

Jeffrey C Andle

George Phillips O'Brien

David Daniel George Vile

Arthur Richard Metcalf

Alexander Thomas James Stopps

George E Bown

Graham Michael Freakes

Peter John Beckley

A SAW sensor arrangement includes a transducer including a support for supporting a SAW device. The support includes a sensor location part located between two oppositely extending attachment parts. The SAW device is mountable to the sensor location part. The sensor arrangementincludes at least two spaced friction raisers. The sensor arrangement includes a clamp arrangement which applies a clamping force to clamp the sensor arrangement to an item. The sensor arrangement is arranged so that in use each of the friction raisers is located between a different one of the attachment parts and the item.

Saw sensor arrangements

Quartz cuts are provided which exhibit temperature characteristics which are favorable for making differential SAW temperature sensors. Families of Y cuts rotated between 0&#xb0; and 60&#xb0; degrees in combination with placement of two resonators at specified angles to each other are disclosed. Further, preferred embodiments in which the resonators are placed on opposite sides of a zero TCF line are disclosed, to provide wide temperature differences while efficiently utilizing the available bandwidth. The design permits placement of the resonator at angles smaller than 12.5&#xb0; and even less than 5&#xb0; therebetween, most preferably on quartz rotated Y cut between 28.5&#xb0; and 42.75&#xb0;.

Quartz substrate orientations for compact monolithic differential temperature sensor, and sensors using same

A method of wirelessly interrogating a sensing device comprising a plurality of passive sensors, to determine a measurement parameter, comprises the steps of repeatedly interrogating the sensing device using a predetermined transmission signal and detecting the response; estimating the measurement parameter for each sensor by means of an analysis of the data accumulated as a result of the interrogation step, and determining the average of the parameters derived from the estimating step for each sensor, using a weighted average, in which the weightings depend on the amplitude of the sensor response. The measurement parameter may be a resonant frequency where the passive sensors are resonant devices, and the sensors may be SAW devices.

Interrogation method for passive wireless sensor interrogation system

A contactless SAW based torque and temperature sensor comprising a first () and second () SAW resonator provided on a substrate made of Y+34&#xb0; cut of quartz. The first SAW resonator () has its principle axis inclined at +45&#xb0; to the X-axis of the substrate, which, in use is either aligned with the longitudinal axis of the device who torque is to be measured or is perpendicular thereto, and the second SAW () has its principle axis inclined at &#x2212;45&#xb0; to the X-axis of the substrate. A third SAW () has its principle axis inclined at an angle of 30 degrees to the X-axis of the substrate. Each said SAW resonator () is formed by laying a film of aluminum on the substrate having a thickness (h) and the SAW resonators have an average operating wavelength &#x3bb; where the ratio h/&#x3bb; is in the range 0.021 to 0.032.

Saw torque and temperature sensor with improved temperature sensitivity

A method of calibrating an individual sensor of a particular sensor type whose output varies non-linearly with at least one measured quantity and at least one operating condition. The first step includes producing a set of calibration curves for each sample sensor of the particular sensor type. The resulting sets of calibration curves are then averaged and the results used to produce a generic calibration surface for the particular sensor type showing its variation. Individual calibration measurements are then taken for a number of different values of the measured quantity at a small number of discrete values. The individual calibration readings are then used to map the generic calibration surface to the individual calibration measurements of the individual sensor.

Method of calibrating temperature compensated sensors

A contactless SAW based torque and temperature sensor includes three SAW resonatorsmounted on a common substratemade of Y+34&#xb0; cut of quartz. The first SAWhas its principle axis inclined at +45&#xb0; to the X-axis of the substrate, which, in use, is either aligned with the longitudinal axis of a device whose torque is to be measured or is perpendicular thereto, and the second SAWhas its principle axis inclined at 135 degrees to the X-axis of the substrate. The third SAWis positioned with its principle axis inclined at an angle, preferably in the range of 0 to 30 degrees, to the principle axis of both the first 2 and second 3 resonators so that none of the SAWs are parallel, the third SAWenabling temperature measurements to be taken.

Saw torque and temperature sensor

A rotary coupler comprises a statorhaving a first faceand a rotorhaving a second face, the first and second facesbeing spaced apart from and facing each other. A first electrically conducting trackis provided on the first faceof the statorwhich forms a transmission line and has spaced apart ends A, B and a second electrically conducting trackis provided on the second surfaceof the rotoralso forming a transmission line and having spaced apart ends C, D. One end A of the first track, in use, is connected to signal generating means and the other end B of the first track is connected to earth through a resistor substantially equal to the characteristic impedance of the transmission line. The first trackextends along a generally circular arc substantially around the first faceof the stator, the first trackhaving a length substantially equal to an integer number of wavelengths of the signal produced, in use, by the signal generating means. The second track () extends along a generally circular arc partially around the second faceof the rotor, the second trackhaving a length substantially equal to one quarter of the wavelength of the signal produced, in use, by the signal generating means.

Large diameter RF rotary coupler used with a passive RF sensor

The present invention relates to a method and apparatus for assessing the condition of a wheel particularly, but not exclusively, to a method and apparatus for assessing the condition of a tire rotating on a vehicle wheel. Apparatus is provided comprising a plurality of antennas () for transmitting an interrogation signal to a sensor (), the sensor being mounted to a wheel to be assessed and being adapted to detect the condition of the wheel; wherein the antennas are arranged in a line along a path to be followed by a wheel to be assessed.

Remote interrogation of a vehicle wheel

A self-contained radio apparatus for the transmission of data includes a resiliently deformable patch, a resiliently deformable antenna carried by the patch, a post secured to the patch and upstanding from an upper surface of the patch, the post providing at an end remote from the patch a mounting for a radio device, and, electrical conductors extending from the antenna to the end of the post remote from the patch for operably connecting the antenna to a radio device mounted on the post. The radio apparatus is useful for attaching to objects that undergo bending stresses, such as tires.

Self-contained radio apparatus for transmission of data

A split ring coupler comprising a stator ring having at least one split in it such that the stator has at least a first and a second end and a rotor ring having at least one split in it such that the rotor ring has at least a first and a second end, said rotor ring being oriented substantially coaxially with and axially spaced apart from said stator ring. At least one SAW resonator is electrically directly coupled between said first and second ends of the rotor ring in series therewith, neither of said ends of said stator ring being connected to ground.

Split-ring coupler incorporating dual resonant sensors

A surface acoustic wave (SAW) sensor includes a transducer (provided on a substrate (), wherein the transducer () is oriented on the substrate () so that the direction of acoustic wave propagation is such that the variation of sensor output with temperature, associated with the variation of the substrate third-elastic constants with temperature, substantially equal but opposite to the sum total of the variation of sensor output with temperature associated with the substrate linear temperature coefficient of expansion and with the variations with temperature of the substrate non-zero third order elastic constants, the substrate first-order elastic constants and the substrate density. The effect of temperature variation on sensor output is thereby minimized. This is achieved with a 35-degree arrangement or with reflective gratings inclined at an angle of 3.1 degrees to normal. Additionally, a robust package with a dish is given. Particular applications include the measurement of torque.

Temperatures stable saw sensor with third-order elastic constants

A system for interrogating a tire sensor. The disclosure provides a wheel () including a sensor () and an electrical conductor () extending about a rotational axis () of the wheel (), the sensor () being electrically coupled to said electrical conductor (). Communication between the sensor and a remote interrogating apparatus is thereby improved.

Tire sensor interrogation and valve therefore

A pressure monitor has a base and a lid secured to the base to define a substantially fluid tight chamber. At least part of the lid is flexible and forms a diaphragm which deflects responsive to changes in fluid pressure surrounding the monitor. A projection provided on the diaphragm transmits movement thereof to a distortable substrate located within the chamber. A first SAW device is mounted on the distortable substrate, and at least a second and third SAW device are mounted within the chamber. The second SAW device carried on a reference substrate section has its direction of propagation inclined at an angle to the direction of propagation of at least one of the first and third SAW devices. This way movement of the diaphragm induced by a change in pressure in the zone surrounding the monitor results in distortion of the distortable substrate, which is measurable by the SAW device mounted thereon, without distorting said reference substrate section.

Pressure monitor incorporating saw device

An arrangement for tracking resonant frequency of electrically resonant structures through a single channel includes a variable frequency oscillator associated with each resonant structure which provides an excitation signal of a variable frequency encompassing a possible resonant frequency of the associated resonant structure. Coupling device(s) are provided which connect each variable frequency oscillator to said resonant structure(s). An I-mixer is provided for each oscillator which forms a synchronous detector, a first input of each I-mixer being connected to its associated oscillator and a second input being connected to the coupling device, each I-mixer mixing the excitation signal from the associated variable frequency oscillator with a response signal generated by the resonant structure(s) in response to each excitation signal. The output of each I-mixer is filtered to remove sum products of the excitation and response signals, thereby leaving an amplitude modulation component of the signal, which is processed in a control loop to track the resonant frequency of each resonant structure.

Method and apparatus for tracking a resonant frequency

A method of determining the frequency of a plurality of resonant devices (for example three SAW devices) includes determining optimal interrogation frequencies for each of the devices, the optimal interrogation frequencies having maximum power spectral densities, accumulating a plurality of responses for each sensor, performing discrete Fourier transforms on the sampling results to estimate the three resonant frequencies, and averaging the results of the Fourier transforms to provide an indication of resonant frequencies. The averaging step may include the calculation of a standard deviation and the rejection of any results which fall more than a pre-determined multiple of the standard deviation from the average frequency result. The frequency determined by the method may be employed to calculate the pressure and temperature of the sensor devices. The sensor devices may be located in a vehicle tire.

Growing community of inventors

Headington, United Kingdom

Victor Alexandrovich Kalinin