Abstract:
A dual vibrating beam force transducer having an electrostatic drive system. The transducer comprises a body (12) having first and second generally parallel beams (20, 22), coupled together at their ends. First and second electrodes (14, 16) are positioned adjacent to but not in contact with the respective beams. A drive circuit (18) causes an oscillating voltage to be applied to the electrodes. The beams are thus subjected to electrostatic forces that cause the beams to oscillate in a vibration plane containing both beams. The mechanical resonance of the beams controls the oscillation frequency, such that the frequency is a function of a force exerted along the beams. An embodiment is also described in which the drive means is coupled directly to one of the beams.
Abstract:
A textile-based sensor includes a textile triboelectric nanogenerator sensor attached to and overlying a textile piezoresistive sensor, wherein the textile triboelectric nanogenerator sensor is configured to generate an electrical signal indicative of object contact force and/or frequency with the textile triboelectric nanogenerator sensor, object material, and object surface morphology or texture, and the textile piezoresistive sensor is configured to generate an electric signal indicative of the applied external pressure to the sensor, wherein the textile triboelectric nanogenerator sensor overlies the textile piezoresistive sensing.
Abstract:
A bearing detection device comprises a housing body, to be fixed to a stationary ring of a bearing, and a detection arrangement on the housing body, comprising a piezoelectric transducer. The detection arrangement also comprises: a floating body, mounted on the housing body and suitable for mechanically transmitting vibrations of the bearing, and a sensor unit, which is mounted in a stationary position on the housing body and has a detection surface configured for receiving thereon a corresponding surface of the floating body. The piezoelectric transducer defines at least part of the detection surface and is configured for generating an electrical potential difference that is substantially proportional to the magnitude of a stress exerted by the floating body on the piezoelectric transducer.
Abstract:
A method for determining sensor parameters of an actively-driven sensor system may include obtaining as few as three samples of a measured physical quantity versus frequency for the actively-driven sensor system, performing a refinement operation to provide a refined version of the sensor parameters based on the as few as three samples and based on a linear model of an asymmetry between slopes of the measured physical quantity versus frequency between pairs of the as few as three samples, iteratively repeating the refinement operation until the difference between successive refined versions of the sensor parameters is below a defined threshold, and outputting the refined sensor parameters as updated sensor parameters for the actively-driven sensor system.
Abstract:
A double-side-coated surface stress sensor includes a sensing membrane structure portion where at least two ends opposite each other are fixed on a mounting portion; a receptor layer that coats both surfaces of the sensing membrane structure portion; and an element detecting a stress, which is provided in the vicinity of at least one of the fixed two ends, opposite each other, of the sensing membrane structure portion or at least one of the fixed two ends, opposite each other, of the mounting portion, in which in a detection output is obtained from the element based on the stress which is applied onto the receptor layer coating the both surfaces of the sensing membrane structure portion. Accordingly, it is possible to provide a double-side-coated surface stress sensor which coats both surfaces of the sensing membrane structure portion by the receptor layer, thereby obtaining a sufficiently large detection output.
Abstract:
A sensor interface is disclosed including a flexible substrate in which are embedded sensors for measuring physical parameters such as temperature, displacement, velocity, acceleration, stress, strain, pressure and force present between objects such as a railcar bearing and a truck side frame. The substrate is positioned between the objects of interest Electronic components such as a data processing unit, a data storage device, a communication device and a power source may also be embedded within the substrate. The electronic devices communicate with one another and the sensors to process signals generated by the sensors indicative of the parameters being measured.
Abstract:
An apparatus and method for monolithic force transducers in which a sensed force is applied across only two ends of a pair of force sensing elements so that the pair of force sensing elements are loaded in series with one in compression and the other in tension, whereby the force sensed by each of the two force sensing elements are identically equal in magnitude but opposite in sense.
Abstract:
A resonant sensor comprises a support structure comprising two support points; a laminar resonator suspended between said two support points of said support structure and comprising a plurality of substantially parallel flexural members which are responsive to relative movement of said support points; means for exciting said resonator into a balanced mode of oscillation and means for sensing motion of said resonator. Said means for sensing motion of said resonator is or are spaced from, and linked to, said flexible area of said resonator by means of levers. Said support points are preferably adapted to move relative to each other in response to a difference in pressure, force or acceleration.
Abstract:
A method of forming apparatus including a force transducer on a silicon substrate having an upper surface, the silicon substrate including a dopant of one of the n-type or the p-type, the force transducer including a cavity having spaced end walls and a beam supported in the cavity, the beam extending between the end walls of the cavity, the method including the steps of: (a) implanting in the substrate a layer of a dopant of said one of the n-type or the p-type; (b) depositing an epitaxial layer on the upper surface of the substrate, the epitaxial layer including a dopant of the other of the n-type or the p-type; (c) implanting a pair of spaced sinkers through the epitaxial layer and into electrical connection with said layer, each of the sinkers including a dopant of the one of the n-type or the p-type; (d) anodizing the substrate to form porous silicon of the sinkers and the layer; (e) oxidizing the porous silicon to form silicon dioxide; and (f) etching the silicon dioxide to form the cavity and beam.