摘要:
A detection device includes a transmitter configured to transmit an electromagnetic wave or a sound wave as a transmission signal, a receiver configured to receive a signal obtained by reflecting the transmission signal from an object, as a reception signal, a mixer configured to mix the transmission signal and the reception signal and output a mixed signal as an intermediate signal, and a detector configured to detect a motion of the object and a distance to the object from the intermediate signal, wherein the detector performs first sampling of the intermediate signal at a first sampling time in a first time interval when detecting the motion of the object, and the detector performs second sampling at a second sampling time in a second time interval smaller than the first time interval, between adjacent first sampling times when detecting the distance to the object.
摘要:
A survey system including a multibeam echo sounder having a single projector array and a single hydrophone array constructs a multi-signal message and deconstructs a corresponding multi-signal echo to substantially simultaneously perform multiple survey missions.
摘要:
A system and method for measuring the vibrations of a test object, such as a machine shaft or other rotating equipment. The system includes a probe sensor fitting having an ultrasonic speaker and an ultrasonic microphone. The probe sensor fitting includes a temperature and relative humidity sensor. The sensor provides a real time analog output of selectable scales.
摘要:
A method is disclosed for improving performance of a Sodar system adapted to locate discontinuities in the atmosphere by transmitting pulse compression signals such as plural acoustic chirps. The method comprises transmitting the acoustic chirps, receiving acoustic echoes of the chirps, and processing the acoustic echoes to provide an indication of the discontinuities, wherein the processing includes correcting range or resolution error associated with the acoustic echoes.
摘要:
Embodiments of the invention provide apparatus (100) for detecting an erroneous measurement of a range of a target object 20 from a subject object (5) comprising: wireless transmission means (111) for transmitting a signal (111S) having a first frequency from the subject object (5) to the target object (20); detector means (113) for detecting a portion of the signal (113S) reflected from the target object (20) back to the subject object (5); range determination means (131) for determining the range (202) of the target object (20) from the subject object (5) by reference to a time of flight of said portion of the signal (111S), (113S) from the transmission means (111) to the detector means (113); and rate determination means (131) for determining the rate of change of the range (203) by reference to a difference between the first frequency and an apparent frequency of the reflected portion of the signal (113S) detected by the detector means (113), the apparatus (100) being arranged to provide an indication (206) that an erroneous measurement of range has been made if the range (202) determined by the range determination means (131) increases whilst the rate of change of range (203) determined by the rate determination means (131) is negative.
摘要:
A sensing device obtains range-related data—such as Doppler data or pulse time-of-flight data—from a sports projectile during flight. The time course of the range-related data is employed, in light of predictable characteristics of the projectile trajectory, to determine and output an accurate determination of the projectile speed for one or more points of interest in its flight. Such determination of speed may, for instance, be the speed at the time of projectile release, even though range-related data is gathered later in the flight, when the projectile is traveling neither so fast, nor straight at the sensor. Such sensing device may employ inexpensive short-range acoustic Doppler, and be incorporated into a target device that automatically displays to a pitcher-in-training the speed and ball/strike condition of each pitch.
摘要:
An apparatus detects individual guest interactions in an installation (10) for entertaining one or more guests (12). The apparatus comprises one or more directional, velocity-dependent sensors (24), each motion sensor having a field of view covering a different one of the guests. The motion sensor generates a guest-interaction signal (26) when the guest in its field of view moves in an appropriate manner. The motion sensor can be arranged directly above or in front of the guest, depending on the type of motion that is desired to be detected. The sensor can employ an ultrasonic signal to detect motion, which is less susceptible to light and radio-frequency interference. A controller (22) responds to the guest-interaction signals and manipulates a plurality of guest interfaces (18,20,21).
摘要:
An apparatus for measuring small liquid and particle currents on the high-frequency ultrasonic Doppler principle, has three sound transducers (5, 6, 7) directed jointly either in or against the direction of flow (2), distributed over the circumference of the measuring tube (1). One transducer (5) is a transmitter and the two others (6, 7) are receivers. Two mixers (16, 17) are inserted between the transmitter and the two receivers for producing a differential signal from the master frequency and receiving frequency. A third mixer (18) is provided for producing a signal from the differential signal from the first mixer (16) and the differential signal from the second mixer (17).
摘要:
Apparatus for processing data signals such as sonar return signals of the frequency modulated type wherein adverse effects of Doppler dispersion are eliminated which apparatus includes a signal generator providing an inverse replica of that signal which is shifted upwardly in frequency and is transmitted as the sonar signal, a pair of digital time compression units for compressing respective ones of the down-shifted sonar return signal, i.e., a data signal, and the replica signal, a pair of step clock generators each enabling the memory bank contents of the associated time compression unit to be read out at respective various rates thereby varying in steps the time compression ratios of the units and bandpass correlation apparatus including a first balanced modulator for receiving and operating on the compressed output signals of the time compression unit. The output frequencies of the step clock generators vary in steps so that the compressed replica signal frequency is, in effect, translated upwardly by decreasing degrees for a range of predetermined positive relative target velocities and, thereafter, the compressed data signal frequency is translated upwardly by increasing degrees for a range of predetermined negative relative target velocities thereby enabling, in effect, correlation of the data signal with a suitable replica signal for each of a number of predetermined relative target velocities in a predetermined range. The filtered output signal from the first modulator and an output signal of a step oscillator whose output signal frequency varies in steps according to the predetermined relative target velocities are applied to a second modulator to compensate for Doppler-induced frequency shifts in the transmitted sonar signal. The filtered output signal of the second modulator is detected and integrated to provide points on the correlation functions in the range-Doppler plane.
摘要:
Medical ultrasonic doppler instrument in which transmitting and receiving transducers are mounted within a hollow casing on wavetransmission means of solid material cemented within one end of the casing and having planar surface means, preferably at an angle, to engage the skin of a living body being tested. Important features relate to the provision of wave absorpent material between the case and the wave-transmission means, the provision of a barrier between separate solid members to form the wave-transmission means, and the use of a biased amplifierdetector or a product detector.