摘要:
An optical motion detecting device for a flight vehicle includes a base, an optical motion sensor and an operating processor. The optical motion sensor is disposed on the base and adapted to capture a plurality of frames. The operating processor is electrically connected with the optical motion sensor. The operating processor analyzes a pattern within the plurality of frames to acquire displacement of the base relative to a reference plane according to a known height value, and the known height value represents a height that the flight vehicle starts to move.
摘要:
A device for measuring a sound source distribution in three-dimensional space is provided in which tracer particles included around an object are irradiated with a two-dimensional laser sheet within an x-y plane at two times separated by a short time interval, images of the irradiated tracer particles are taken, and two in-plane velocity components of the tracer particles in the laser sheet and one out-of-plane velocity component perpendicular to the laser sheet are measured based on the images taken. Further, the velocity field of the three velocity components in three-dimensional space is measured by obtaining three velocity components within a plurality of planes spaced apart in a z-axis direction perpendicular to the laser sheet and stacking the three velocity components within the plurality of planes in the z-axis direction. The sound source distribution around the object is measured from the velocity field.
摘要:
This invention is a one-dimensional elementary motion detector that measu the linear optical flow in a small subsection of the visual field. This sensor measures motion by tracking the movement of a feature across the visual field and measuring the time required to move from one location to the next. First a one-dimensional image is sampled from the visual field using a linear photoreceptor array. Feature detectors, such as edge detectors, are created with simple circuitry that performs simple computations on photoreceptor outputs. The detection of the feature's location is performed using a winner-take-all (WTA) mechanism on feature detector outputs. Motion detection is the performed by monitoring the location of the high WTA output in time to detect transitions corresponding to motion. The correspondence problem is solved by ignoring transitions to and from the end lines of the WTA output bus. Speed measurement is performed by measuring the time between WTA output transitions. This invention operates in a one-dimensional subspace of the two-dimensional visual field. The conversion of a two-dimensional image section to a one-dimensional image is performed by a specially shaped photoreceptor array which preserves image information in one direction but filters out image information in the perpendicular direction. Thus this sensor measures the projection of the 2-D optical flow vector onto the vector representing the sensor's orientation. By placing several of these sensors in different orientations and using vector arithmetic, the 2-D optical flow vector can be determined.
摘要:
In order to determine the diameter or the radius of a textile yarn cheese during winding, two sensors are placed adjacent the cheese circumference at a fixed circumferential distance from each other to detect surface characteristics of the cheese, and their sensor signals are evaluated in a correlator to form running times. The circumferential velocity of the cheese is calculated by dividing the distance between the sensors by the running times, after which the circumferential velocity and the angular velocity of the cheese are divided to compute the diameter or radius of the cheese.
摘要:
The present invention is directed to methods and apparatuses for performing temporal scanning using ultra-short pulsewidth lasers in which only minimal (micro-scale) mechanical movement is required. The invention also relates to methods for obtaining high-accuracy timing calibration, on the order of femtoseconds. A dual laser system is disclosed in which the cavity of one or more of the lasers is dithered, by using a piezoelectric element. A Fabry-Perot etalon is used to generate a sequence of timing pulses used in conjunction with a laser beam produced by the laser having the dithered laser cavity. A correlator correlates a laser pulse from one of the lasers with the sequence of timing pulses to produce a calibrated time scale. The methods and apparatuses of the present invention are applicable to many applications requiring rapid scanning and time calibration, including, but not limited to metrology, characterization of charge dynamics in semiconductors, electro-optic testing of ultrafast electronic and optoelectronic devices, optical time domain reflectometry, and electro-optic sampling oscilloscopes.
摘要:
A toy speed measuring and voice reporting system is disclosed. The system measures the speed of a toy car and reports the speed contemporaneously in audible speech. The system employs optical detectors and timing circuitry to compute the speed, and a voice synthesizer to sound the speed values and other messages.
摘要:
A sampled-continuous probability method of velocity measurement of an object having informatively-structural inhomogeneity by periodical execution of a cycle of the measurement, with determination of time during which a selected local part of the object moves along the measuring base of zone of observation is proposed. Selection of the local part in the beginning of the measuring base and its subsequent determination at the end of the measuring base is performed with the use of an informative aggregate of selected informative signs of a dominant informative component of the inhomogeneity. In order to increase the accuracy and speed of the method, the beginning of each cycle of velocity measurement is performed in response to a special command formed after the beginning of a preceding cycle of the velocity measurement with a given interval of time of shifting of the cycles, but within the preceding cycle. In each cycle of the velocity measurement a total time of execution of last stages connected with the computation and saving of the measuring information is selected smaller than minimum possible working step of time quantization of the velocity to be measured. Probability estimates of various time characteristics of the dominant informative component are used to provide invariability of metrological characteristics of the method to changes of the velocity to be measured within a wide dynamic and frequency range.
摘要:
There is provided a laser speckle velocity-measuring apparatus comprising: a semiconductor laser to irradiate the light to a moving object; first and second photo sensing devices whose light receiving points are arranged in the moving direction of the objects at a predetermined distance so as to be away from each other; a clock signal generating and control circuit for determining a clock frequency of the clock signal so that the number of clocks of the clock signal is always set to a constant value when the delay time of the photo sensing signal of the second photo sensing device for the photo sensing signal of the first photo sensing device is measured by the clock signals; and an arithmetic operating circuit for counting the clock signals and calculating the length, moving distance, or velocity of the object on the basis of the count value. With this apparatus, the detecting time of the length or velocity of the moving object can be reduced and the measuring processes can be performed in a real-time manner.
摘要:
The velocity of a liquid jet, such as the headbox jet of a paper making machine, is measured by cross-correlation of a.c. signal components produced by a pair of light beams received by a pair of photodiodes. The light is supplied by a single source, an incandescent lamp, and is guided by a pair of bifurcated fiber optics mounted above the jet and spaced apart in the flow direction. The a.c. components are filtered to remove flow frequencies, amplified and then analyzed in a spectrum analyzer.
摘要翻译:液体射流的速度,例如造纸机的流浆箱喷射,是通过交流相关来测量的。 由一对光电二极管接收的一对光束产生的信号分量。 光源由单一源(白炽灯)提供,并由安装在射流上方的一对分叉光纤引导,并沿流动方向间隔开。 a.c. 过滤组分以除去流动频率,然后放大,然后在频谱分析仪中进行分析。
摘要:
A radiation detection method utilizing essentially two serial arrangements of receiving elements which are rigidly connected to a reconnaissance plane (1) and of different lengths, which yield in longitudinal direction of sight the censor angle .epsilon. and on the ground the pictorial strips (6, 6'). The pictorial strips are arranged transverse to the axis (25) of the plane and parallel to each other. The processing of the signals is such that, by scanning the two serial arrangements with a time delay, a different signal signature results only if the scanned object (2) moves during over flight, independently of whether the reconnaissance plane (1) during the measuring operation is subject to a pitch angle .alpha. and/or a side slip angle .beta. and/or a roll angle speed. Moreover, in this way, it is also possible to independently obtain the target speed and direction.