747results about "Force measurement by measuring magnetic property varation" patented technology

A capacitive encoder includes a signal-balanced shield electrode configuration that does not require electrical ground connection or active sensing and control in order to maintain the shield electrode(s) at a sufficiently constant voltage during capacitive position measurements. The shield electrode configuration is positioned in a capacitive coupling gap between transmitter electrodes and receiver electrodes during operation. The shield electrode configuration is patterned in a manner that complements the layout of the transmitter electrodes, such that the shield electrode configuration inherently floats at a nominally constant electrical potential when coupled to the signals present on the transmitter electrodes. The resulting capacitive encoder is thus more economical to build, convenient to install, and reliable during operation than capacitive encoders which use an electrical connection, compensation drive circuitry, or grounding in order to control the potential of a shield member that operates at a potential that is not inherently constant.

An electronic device includes a number of n Hall effect regions with n>1, wherein the n Hall effect regions are isolated from each other. The electronic device also includes at least eight contacts in or on surfaces of the n Hall effect regions, wherein the contacts include: a first and a second contact of each Hall effect region. A first contact of the (k+1)-th Hall effect region is connected to the second contact of the k-th Hall effect region for k=1 to n−1, and the first contact of the first Hall effect region is connected to the second contact of the n-th Hall effect region. The at least eight contacts include at least two supply contacts and at least two sense contacts. Each Hall effect region includes at most one of the at least two supply contacts and at most one of the at least two sense contacts.

An improved method of sensing strain allows measurements of stress, torque, vibration and other loads imposed on a body without physical contact between the body/sensor and the monitoring equipment. An induction loop is at least partially comprised of a magnetostrictive material with a non-linear current-voltage relationship. An excitation device such as a coil is used to induce an AC response in the sensor. The non-linear response to the induced current is received by a sensing device such as a sensing coil, and the output thereof is filtered. The excitation device and sensing device are located in operative proximity to the sensor, but need not be in contact therewith, allowing easy measurement in small spaces, under harsh conditions, or of moving bodies such as drive shafts. The non-linear response of the sensor induces easily detectable harmonics of the base frequency of excitation. These harmonics may advantageously be measured as well.

This disclosure, in one aspect, provides an apparatus for use in a wellbore that includes a member having an encoded magnetic field and a sensor proximate the encoded magnetic field that measures a change in the magnetic field due to a change in the load on the member. In another aspect, a method for measuring loads on a downhole tool is provided that comprises inducing an encoded magnetic field along a section of a member of the tool and detecting a change in the magnetic field due to a load on the member when the tool is in the wellbore.

The problem of magnetoelastic cirumferentially-magnetized torque transducers having a zero output magnetic field at zero torque is solved by pre-torqueing. This entails is circumferentially magnetizing the transducer element at a predetermined torque. The technique is advantageously applied to a pair of transducer elements (32, 34: 62, 64) whose outputs are combined (FIG. 6a: 76) to provide a range of measurement of torque (clockwise and counterclockwise) including zero torque. Various combinations of direction of pre-torque and direction of circumferential-magnetization are discussed. A circuit (FIG. 8) is disclosed for combining the signals to obtain a reference level (84) for gain control of the combined output signals V o from the two transducer elements (60, 62). Also disclosed is the application of the invention to other forms of torque transducer element in which a magnetic field is stored. One form is longitudinal magnetization (FIG. 10a). Another is radially spaced magnetization (FIG. 12a: FIG. 13).

A seat belt tension sensor assembly includes a housing, a slider slidably received within the housing, wherein the slider is configured for movement between a first position and a second position within the housing, and a first and second magnet associated with the slider for slidable movement therewith. The first and the second magnets are positioned side by side with opposite polarization. A hall effect device is fixed relative to the housing and protrudes between the first and the second magnets when the slider is in the second position. The hall effect device is configured to produce an output signal, the output signal being indicative of a seat belt tension of a seat belt as applied to the sensor assembly. A biasing member provides an urging force to the slider, the urging force urging the slider into the first position.

A measurement module that measures force being applied to a man-powered machine includes: a strain sensor that detects strain of a crank of the bicycle configured to transmit force being applied from a user through the crank and one front gear selected among one or more front gears; an MM magnetic sensor that detects the crank passing through a predetermined position; and an MM control part. The MM control part calculates a rotation angle of the crank based on an elapsed time from a time the crank passes through the predetermined position that the sensor has detected, calculates force applied to the crank based on a strain amount of the crank that the strain sensor has detected, associates the rotation angle with the force applied to the crank to calculate distribution of the force applied from the user.

A magnetic force sensor includes: an action portion on which an external force acts; a sensing unit converting a force working on the action portion into an electric signal; and an outer frame having an elastic body elastically supporting the action portion and storing the sensing unit therein. The sensing unit includes a magnetic flux generation source connected with the action portion and a magnetoelectric transducer fixed on the outer frame and the magnetic flux generation source has a magnetic body therewith that controls flow of magnetic fluxes generated by the magnetic flux generation source.

The invention relates to a flexible electronic pressure sensing device capable of sensing a large area and being manufactured at low cost and a manufacturing method thereof. The device comprises multiple layers of flexible films, a plurality of electrodes, a plurality of sensing blocks and a plurality of bumps, wherein the flexible films are arranged at intervals to define two spaces; the electrodes and the sensing blocks are arranged on the flexible films and positioned in one space; and the bumps are arranged on the flexible films and positioned in the other space. The air in the spaces maintains a relative distance between two flexible films which are provided with the electrodes and the sensing blocks. In case of deformation, the flexible electronic pressure sensing device can avoid error sensing signals caused by the mutual contact of the sensing block and the electrode or two sensing blocks respectively arranged on different flexible films. In addition, the invention also relates to the method for manufacturing the flexible electronic pressure sensing device.

A new type of magnetoelastic device for sensing force is described. It comprises of two elements: a circumferentially magnetized member comprised of magnetoelastically active material mounted as a beam and loaded by the force to be sensed, and a magnetic field sensor mounted at or near the member's surface, preferentially at or near a longitudinal location where the bending moment is maximum and at a circumferential location where the bending stress is zero. Flexural loading causes a variation of the circumferential magnetization with angular position. This variation is the source of free poles, the field from which is a measure of the applied force. Testing demonstrates that the field intensity is a linear analog of the experienced bending stress over a significant range of applied push and pull forces.

A device for discovering, identification and monitoring, of mechanical flaws in metallic structures is disclosed, based on magneto-graphic/magnetic tomography technique to identify stress-related defects. The device can determine the position of the defect or stress including depth information. The device includes registration means that optimized for use with metallic structures of various types, shapes, and sizes. Applications include a real-time quality control, monitoring and emergency alarms, as well structural repairs and maintenance work recommendations and planning. Examples of the device implementation include pipes for oil and gas industry monitoring, detection of flaws in roiled products in metallurgical industry, welding quality of heavy duty equipment such as ships, reservoirs, bridges, etc. It is especially important for loaded constructions, such as pressured pipes, infrastructure maintenance, nuclear power plant monitoring, bridges, corrosion prevention and environment protection.

A microelectromechanical system (MEMS) sensor and method for measuring the motion of an intermediate member and a method for making the MEMS sensor. The MEMS sensor includes a substrate, a lower magnetic member disposed on the substrate, a layer disposed over the substrate, an upper magnetic member disposed at a side of the layer facing the lower magnetic member, an intermediate magnetic member magnetically levitated between the lower magnetic member and upper magnetic member; and a component measuring at least one of motion, forces acting on, and a displacement of the intermediate magnetic member.

A strain gauge sensor system and method for measuring the strain in a member, such as a fiber rope, has a sensor target assembly having a plurality of magnets carried spaced apart by individual gauge lengths along the member. Position and trigger sensor devices are configured spaced apart along side a desired path of travel of the member. When the member is fed along the desired path of travel, the trigger sensor device, in response to magnetically sensing a passing magnet, triggers the position sensor device to read the position of an adjacent passing magnet. The strain in the gauge length is determined from the read position. RFID tags placed on the member between the magnets can be identified by an RF reader to identify a particular gauge length being measured. The system can include a deployment device for feeding the member along the desired path.

The invention discloses a measuring device and a measuring method for alternating stress of a ferromagnetic component, is used for measuring the stress direction and the stress intensity of the ferromagnetic component, and belongs to the field of nondestructive measuring technologies and devices. The measuring device comprises a signal excitation module, an excitation probe, a detecting coil, a signal conditioning module, a signal acquisition module and a computer signal processing analysis module. The measuring device and the measuring method disclosed by the invention have the substantial characteristics that a to-be-detected component is magnetized by utilizing a U-shaped probe with an alternating signal, so that stress area is enough in secondary induced magnetic field, and then, an induced magnetic field of representing stress information is picked up by the detecting coil, and therefore, the goal of identifying the stress is achieved. According to the measuring method, by utilizing a set of detecting systems, not only can the stress degree of the surface and the near surface of the ferromagnetic component be evaluated but also the major stress direction in the component can be determined. The measuring device and the measuring method for the alternating stress of the ferromagnetic component are wider in application prospect.

The invention provides a load detecting system comprising a core (83) of magnetostrictive material, a coil (85) disposed in the vicinity of the core, and a load detecting circuit (10) connected to the coil (85) for detecting the magnitude of a load acting on the core (83). The load detecting circuit (10) comprises an exciting circuit (102) for passing an a.c. detecting current through the coil (85), a pulse current generating circuit (103) for passing through the coil a detection preparing current having a current value greater than the maximum value of the detecting current, a change-over circuit (104) for effecting a change-over between the exciting circuit (102) and the pulse current generating circuit (103) to pass the detecting current through the coil after passing the detection preparing current therethrough, and a microcomputer (100) for deriving the magnitude of the load acting on the magnetostrictive element based on an impedance variation produced in the coil during the period of passage of the detecting current through the coil.

A method, apparatus and system of capacitive sensor based inventory control is disclosed. In one embodiment, an inventory management system includes a first conductive surface and a second conductive surface substantially parallel to the first conductive surface, a sensor to generate a measurement based on a change in a distance between the first conductive surface and the second conductive surface, a scale formed with a set of plates having inserted between the set of plates the first conductive surface and the second conductive surface and a container placed above the scale such that an item (e.g., a liquid, a solid, a discrete part, a powder and/or a gas, etc.) of the container is weighed through the measurement. The inventory management system may further include a reference capacitor associated with the apparatus to enable the sensor to adjust the measurement based on the environmental condition.

The present invention provides a pressure sensing device that includes at least one TMR sensor, and preferably an array of TMR sensors, with each TMR sensor having an insulating spacer layer interposed between a pinned and a free ferromagnetic layer. In an unbiased state, the magnetization vector of each of the ferromagnetic layers is preferably parallel to each other. Upon application of a small voltage, the magnetization vectors remain unchanged. Upon application of stress, the magnetization vector of the free magnetic layer will rotate, thus causing a corresponding and proportionally related change in the resistance of the sensor. This change in resistance can be sensed and used to calculate the stress applied thereto.