A sensor detects tilt and/or accelerations simultaneously and in a plurality of directions. The exemplary sensor comprises a magnet which is allowed to move in multiple directions within a space about which a plurality of Hall-effect sensors are arrayed. The magnet is mounted by a plurality of springs which limit the displacement of the magnet to the space within the circle of sensors. Continuous signals from the sensors change in response to a changing position of the magnet. These signals are evaluated by an artificial neural network (ANN) taught using validated tilt sensors. Angle and acceleration values are cleaned from vibration values using a Kalman filter.

A sensor detects tilt and/or accelerations simultaneously and in a plurality of directions. The exemplary sensor comprises a magnet which is allowed to move in multiple directions within a space about which a plurality of Hall-effect sensors are arrayed. The magnet is mounted by a plurality of springs which limit the displacement of the magnet to the space within the circle of sensors. Continuous signals from the sensors change in response to a changing position of the magnet. These signals are evaluated by an artificial neural network (ANN) taught using validated tilt sensors. Angle and acceleration values are cleaned from vibration values using a Kalman filter.

This invention describes a magnetoresistive inertial sensor chip, comprising a substrate, a vibrating diaphragm, a magnetic field sensing magnetoresistor and at least one permanent magnet thin film. The vibrating diaphragm is located on one side surface of the substrate. The magnetic field sensing magnetoresistor and the permanent magnet thin film are set on the surface of the vibrating diaphragm displaced from the base of the substrate. A contact electrode is also arranged on the surface of the vibrating diaphragm away from the base of the substrate. The magnetic field sensing magnetoresistor is connected to the contact electrode through a lead. The substrate comprises a cavity formed through etching and either one or both of the magnetic field sensing magnetoresistors and the permanent magnet thin film are arranged in a vertical projection area of the cavity in the vibrating diaphragm portion. A magnetic field generated by the permanent magnet thin film changes in the sensing direction of the magnetic field sensing magnetoresistor of magnetoresistive inertial sensor chip, which changes the resistance valve of the magnetic field sensing magnetoresistor, thereby producing a change in an output electrical signal. This magnetoresistive inertial sensor chip uses the high-sensitivity and high-frequency response characteristics of a magnetoresistor to improve the output signal strength and frequency response, thereby facilitating the detection of small and high frequency pressure, vibration, or acceleration changes.

An apparatus for orienting an accelerometer on a post-tensioned rod is provided. The apparatus includes a first open channel having a first sidewall forming a substantially half cylinder shape along at least a portion of a length of the first open channel, and a first axis along a length of the first open channel. The apparatus further includes a second open channel having a second sidewall forming a substantially half cylinder shape along at least a portion of a height of the second open channel, and a second axis along a height of the second open channel. The apparatus further includes a stopper wall having an inner surface disposed internal to a top end of the second channel. The inner surface of the stopper wall is substantially perpendicular to the second axis. The first axis is substantially perpendicular to the second axis. The first and second channels are contiguous.

The present disclosure discloses a vertical superconducting magnetic mass-spring oscillator with an adjustable natural frequency, comprising: a proof mass, a negative-stiffness superconducting coil and a positive-stiffness superconducting coil; the negative-stiffness superconducting coil is mounted at an opening of a semi-closed space of the proof mass, so that a part of magnetic lines of the negative-stiffness superconducting coil are in a compressed state in a closed space of the proof mass, and the other part of the magnetic lines of the negative-stiffness superconducting coil are in an expanded state outside the closed space of the proof mass; a vertical magnetic repulsive force applied to the proof mass by the negative-stiffness superconducting coil varies with a displacement of the proof mass from an equilibrium position, with the variation magnitude proportional to the displacement and the variation direction the same as the displacement direction; and the positive-stiffness superconducting coil is mounted in the semi-closed space of the proof mass, and a vertical magnetic repulsive force applied to the proof mass by the positive-stiffness superconducting coil varies proportionally to the displacement of the proof mass from the equilibrium position, with the variation direction opposite to the displacement direction. The present disclosure realizes that the natural frequency of the superconducting mass-spring oscillator is adjustable, and meanwhile, the cross-coupling effect of horizontal and vertical degrees of freedom of the proof mass can be reduced.

The present disclosure discloses a vertical superconducting magnetic mass-spring oscillator with an adjustable natural frequency, comprising: a proof mass, a negative-stiffness superconducting coil and a positive-stiffness superconducting coil; the negative-stiffness superconducting coil is mounted at an opening of a semi-closed space of the proof mass, so that a part of magnetic lines of the negative-stiffness superconducting coil are in a compressed state in a closed space of the proof mass, and the other part of the magnetic lines of the negative-stiffness superconducting coil are in an expanded state outside the closed space of the proof mass; a vertical magnetic repulsive force applied to the proof mass by the negative-stiffness superconducting coil varies with a displacement of the proof mass from an equilibrium position, with the variation magnitude proportional to the displacement and the variation direction the same as the displacement direction; and the positive-stiffness superconducting coil is mounted in the semi-closed space of the proof mass, and a vertical magnetic repulsive force applied to the proof mass by the positive-stiffness superconducting coil varies proportionally to the displacement of the proof mass from the equilibrium position, with the variation direction opposite to the displacement direction. The present disclosure realizes that the natural frequency of the superconducting mass-spring oscillator is adjustable, and meanwhile, the cross-coupling effect of horizontal and vertical degrees of freedom of the proof mass can be reduced.

A system and method wherein ball spin rate and axis orientation are determined according to an electronic circuit that includes a magnetometer spin sensor module and, in the alternative, an electronic circuit that includes a spin sensor module with a plurality of accelerometers.

A system and method wherein ball spin rate and axis orientation are determined according to an electronic circuit that includes a magnetometer spin sensor module and, in the alternative, an electronic circuit that includes a spin sensor module with a plurality of accelerometers.

Range and orientation of a transmitter and a receiver are found by detecting the magnetoquasistatic field couplings between coils at the transmitter and receiver. Sum functions and ratio functions are calculated for each of the unique magnetoquasistatic field couplings between the transmitter and the receiver. The sum and ratio functions are inverted to determine the drift-free range and orientation. Linear and angular velocity and acceleration are calculated by applying a filter to reduce noise, and then taking the corresponding derivatives.

A system for estimating tension in a post-tensioned rod is provided. The system includes an impact device for transversely-impacting a post-tensioned rod, an accelerometer configured to generate data indicative of a vibrational response in the post-tensioned rod, and a receiver communicatively coupled to the accelerometer. The receiver includes a display, at least one input device, a communication module, a processor, and one or more memory devices coupled to the processor. Instructions stored on the one or more memory devices, when executed by the processor, cause the processor to receiver the data indicative of a vibrational response in the post-tensioned rod, process the received data to determine a difference between a first and a second modal frequency corresponding to the vibrational response, and store the difference between a first and second modal frequency corresponding to the vibrational response. The receiver is configured to transmit the stored difference between a first and second modal frequency.