Abstract: The invention discloses an omnidirectional vector electrostatic levitation geophone, comprising: a regular tetrahedron hollowed-out structure, and an inner hollowed-out base and an outer hollowed-out base that are provided inside and outside the regular tetrahedron hollowed-out structure and at equal distance from the regular tetrahedron hollowed-out structure, and have the same structure as and different size from the regular tetrahedron hollowed-out structure; the regular tetrahedron hollowed-out structure has a solid part and a hollowed-out part of each surface thereof, the solid part is a quadrangle divided from angular bisectors of two angles on each surface and an isosceles triangle that abuts the solid part by a surface central point, and the hollowed-out part is two triangles that are divided from the angular bisectors of the two angles and abut each other by a surface center.

Abstract: Apparatuses and methods are described for determining displacement and/or rotation of a Unmanned Aerial Vehicle (UAV), including, but not limited to, determining a first Time of Flight (ToF) for audio signals transmitted by an audio transmitter of the UAV and received by a first audio receiver of the UAV while the UAV is in motion, determining a second ToF for the audio signals transmitted by the audio transmitter and received by a second audio receiver of the UAV while the UAV is in motion, and determining the displacement or the rotation of the UAV based, at least in part, on the first ToF and the second ToF.

Abstract: The present device is an object detection device for assisting individuals with visual impairments to detect objects in front of him or her when walking or riding a bike. The device preferably includes an assistive device like a cane and an echolocation device coupled to the walking assistive device. When a user signals for the echolocation device to do so, the echolocation device uses a parametric array to generate a sound beam. If an object is in front of the user, the audible narrow sound beam reflects off of the object creating a strong, clear echo sound beam toward the user's ear. Because the user is preferably trained in echolocation, he or she is able to determine the distance, position, and possibly the type of object.

Abstract: An ultrasound system (1) is disclosed that comprises a probe (10) including an array (110) of CMUT (capacitive micromachined ultrasound transducer) cells (100), each cell comprising a substrate (112) carrying a first electrode (122), the substrate being spatially separated from a flexible membrane (114) including a second electrode (120) by a gap (118); and a bias voltage source (45) coupled to said probe and adapted to provide the respective first electrodes and second electrodes of at least some of the CMUT cells with a monotonically varying bias voltage including a monotonically varying frequency modulation in a transmission mode of said probe such that the CMUT cells are operated in a collapsed state and transmit at least one chirped pulse during said transmission mode. Such a system for instance may be an ultrasound imaging system or an ultrasound therapeutic system. An ultrasonic pulse generation method using such as system is also disclosed.

Abstract: A system for searching for underground entities in ground of an area, including a search probe configured to generate and deliver an acoustic signal into the ground of the area, wherein the acoustic signal uses a low frequency signal so that wavelengths of the acoustic signal are between 0.01-500 times the depth to the sought underground entity, two or more sensors positioned on the ground at about an equal distance from the search probe at different angles, an analysis device that receives measurements from the two or more sensors in the form of a measured echo signal responsive to the delivered acoustic signal, wherein said analysis device designates pairs of sensors and subtracts their echo signals to identify a difference indicating the existence of an underground entity.

Abstract: An electronic home plate provides assistance to an umpire in determining whether a pitch results in a “strike” or a “ball.” The home plate is implemented with LEDs producing discrete pulses of infrared light beams extending vertically. As a moving ball intersects the pulses, light from the pulses is scattered and incident on photodetectors embedded in the home plate, producing a series of data points. Two stages of light compensation compensate the data points for ambient light, first by applying an offset current to a photodetector through a PNP transistor, and second by subtracting a measurement immediately before a pulse from a measurement during the pulse. A processor then fits the data points to a curve, to compute vertical and lateral positions of the ball, thereby determining whether the pitch passed within a strike zone. Other applications may similarly analyze the trajectory of other projectiles for various purposes.

Abstract: In a method of operating a two-dimensional array of ultrasonic transducers, a plurality of array positions comprising pluralities of ultrasonic transducers of the two-dimensional array of ultrasonic transducers is defined, the plurality of array positions each comprising a portion of ultrasonic transducers of the two dimensional array of ultrasonic transducers. For each array position of the plurality of array positions, a plurality of ultrasonic transducers associated with the respective array position are activated. The activation includes transmitting ultrasonic signals from a first group of ultrasonic transducers of the plurality of ultrasonic transducers, wherein at least some ultrasonic transducers of the first group of ultrasonic transducers are phase delayed with respect to other ultrasonic transducers of the first group of ultrasonic transducers, the first group of ultrasonic transducers for forming a focused ultrasonic beam.

Abstract: The invention relates to a sensor and a system for measuring pressure, variation in sound pressure, a magnetic field, acceleration, vibration, or the composition of a gas. The sensor comprises an ultrasound transmitter, a cavity, and a passive sensor element. In accordance with the invention the sensor includes antenna means for receiving radio frequency signals (f1, f2), and connecting means connecting the antenna to the ultrasound transmitter for using the radio frequency signals for providing energy for driving the ultrasound transmitter.

Abstract: Embodiments relate to relate to marine vibrators that incorporate one or more piston plates that act on the surrounding water to produce acoustic energy. An example marine vibrator may comprise: a containment housing; a piston plate; a fixture coupled to the containment housing; a mechanical spring element coupled to the piston plate and the fixture; a driver disposed in the marine vibrator, wherein the driver is coupled to the piston plate and the fixture; and a container coupled to the piston plate, wherein the container is configured to hold a variable mass load; wherein the marine vibrator has a resonance frequency selectable based at least in part on the variable mass load.

Abstract: A building monitoring and control system in furtherance of engaging a detected and targeted threat to persons in or about the building is provided. The system is characterized by a threat detection module, a threat targeting module, a threat tracking module, and threat engaging assemblies. The threat detection module is provided in the form of a multi-modal sensor array or network system deployable or integral with a monitored building. Threat targeting and tracking modules are operatively linked to the threat detection module, and each other. Threat engaging assemblies, in the form of water cannons selectively deployable or integral with a monitored building, are operatively linked to at least the tracking module in furtherance of disrupting a located and trackable threat with water discharged from multiple water discharge nozzles of the water cannons.

Abstract: The invention relates to a method for detecting an object in an opening area of a first door (5) of a motor vehicle (1) using at least one first distance sensor (9, 10, 11), the at least one first distance sensor (9, 10, 11) being arranged in and/or on the first door (5) and having a detection area (17, 18, 19), in which a current opening angle (?2) of the first door (5) is detected and the detection area (17, 18, 19) is adapted on the basis of the detected opening angle (?2), a state variable of at least one component of the motor vehicle (1) which differs from the first door (5) being determined, the state variable describing a position and/or an operational setting of the at least one component, and the detection area (17, 18, 19) of the at least one first distance sensor (9, 10, 11) additionally being adapted on the basis of the determined state variable.

Abstract: A dual frequency ultrasound transducer includes a high frequency ultrasound array and a low frequency transducer positioned behind or proximal to the high frequency ultrasound array. In one embodiment, a dampening material is positioned between a rear surface of the high frequency array and the a front surface of the low frequency array. The dampening preferably is high absorbing of signals at the frequency of the high frequency array but passes signals at the frequency of the low frequency transducer with little attenuation. In additional, or alternatively, the low frequency can angled with respect to the plane of the high frequency transducer to reduce inter-stack multipath reflections. Beamforming delays compensate for the differences in physical distances between the elements of the low frequency transducer and the plane of the high frequency transducer.

Abstract: According to one aspect, a system for determining a location of a device is provided. According to one embodiment, the system comprises a management component, a plurality of microphones including a first microphone and a second microphone, at least one receiving component, the at least one receiving component coupled to the plurality of microphones and configured to receive signals from the plurality of microphones related to an acoustic signal detected by the plurality of microphones, determine a first timestamp of the acoustic signal using the signals received from the first microphone, determine a second timestamp of the acoustic signal using the signals received from the second microphone, and send the first timestamp and the second timestamp to the management component, the management component being configured to receive the first timestamp and the second timestamp and calculate the location of the device using the first timestamp and the second timestamp.

Abstract: A Piezoelectric Micromachined Ultrasonic Transducer (PMUT) device is provided. The PMUT includes a substrate and an edge support structure connected to the substrate. A membrane is connected to the edge support structure such that a cavity is defined between the membrane and the substrate, where the membrane is configured to allow movement at ultrasonic frequencies. The membrane includes a piezoelectric layer and first and second electrodes coupled to opposing sides of the piezoelectric layer. An interior support structure is disposed within the cavity and connected to the substrate and the membrane.

Abstract: A system where a large number of underwater devices can transmit their precise position relative to a fixed underwater beacon, by transmitting two short duration, precisely timed acoustic tones (pings). The arrival time of the pulses at the fixed underwater transceiver beacon will relay the transmitter's precise position relative to that beacon. The two pings code for two numbers; either the range and bearing or an X, Y coordinate of each object with respect to the beacon. Data messages can be sent to and received from the beacon, used for command, control and status. The pulses can be a single frequency and have duration of around a 1 ms and operate one or many frequencies to allow multiple cycles to be overlapped in time. This coding scheme allows many devices to send the data simultaneously in the cycle for group tracking from last position or as independent cycles for unambiguous tracking. The transducers used in the system can be omni-directional hydrophones.

Abstract: An exemplary depth scanning system includes first and second depth scanning devices disposed, respectively, at first and second locations on a boundary of a scan zone where segments of the boundary meet to form respective first and second angles that include the scan zone. The first device performs a first sequence of depth scanning operations where the first device detects depth data for surfaces included in the scan zone by sweeping a scan field across the first angle and in which the first device abstains from detecting depth data for surfaces outside the first angle. Concurrently, the second device performs a second sequence of depth scanning operations where the second device detects depth data for the surfaces in the scan zone by sweeping a scan field across the second angle and in which the second device abstains from detecting depth data for surfaces outside the second angle.

Abstract: An ultrasound imaging system (100) includes at least first and second arrays (108) of transducer elements, which are angularly offset from each other in a same plane. Transmit circuitry (112) excites the first and second arrays to concurrently transmit over a plurality of angles. Receive circuitry (114) controls the first and second arrays to concurrently receive echo signals over the plurality of angles. An echo processor (116) processes the received signals, producing a first data stream for the first array and a second data stream for the second array. The first and second data streams include digitized representations of the received echo signals. A sample matcher (118) compares samples of the first and second data streams and determines a cross-correlation there between. A correlation factor generator (120) that generates a correlation factor signal based on the determined cross-correlation.

Abstract: An optical transmitting system for distance measuring includes a modulation signal generator, a light source, and an illumination driver coupled to the modulation signal generator and the light source. The modulation signal generator is configured to generate a modulation signal. The light source is configured to generate an optical waveform with amplitude modulation corresponding with the modulation signal. The illumination driver is configured to drive the light source. The illumination driver includes a switch and a switch driver. The switch is configured to switch between an on state and an off state to drive the light source. The switch driver is configured to drive the switch between the on and off states. The switch driver includes a first inductor and a capacitor in series with the first inductor and the switch.

Abstract: A ladar system and related method are disclosed where the ladar system includes a sensor that senses background light levels. A control circuit of the ladar system (1) measures the sensed background light levels and (2) controllably adjusts a pulse duration for a new ladar pulse based on the measured background light levels. A ladar transmitter can then transmit the new ladar pulse, wherein the new ladar pulse has the adjusted pulse duration. In an example embodiment, this technique for adaptive pulse duration can be employed in the ladar system where the ladar transmitter and ladar receiver are arranged in a bistatic architecture.

Abstract: A pressure compensation device for a downhole fluid pressure pulse generator comprising: a membrane sleeve; a membrane support with a bore for receiving a drive-shaft, a central section which receives the membrane sleeve, a male mating section on each side, each having a groove extending around an external surface and at least one opening aligned with the groove; a pair of female mating components with a bore and a channel in an internal surface, each female mating component configured to mate with one of the male mating sections to axially clamp the membrane sleeve between the membrane support and the female mating components; and a pair of retaining rings each received between the male mating section groove and the female mating component channel, where the retaining rings are accessible through the opening in the male mating section and radially expandable into a space in the female mating component to unseat the retaining ring from the groove for removal.