SU1763891A1 - Method for reflecting post inter-connecting line angles measuring - Google Patents

Description

one

(21) 4784844/10

(22) 11/20/89

(46) 09/23/92. Bul No. 35

(71) Research Institute of Instrument Engineering

(72) T.P.Startsev

(56) Patent of the Federal Republic of Germany Ms 372249 cl. С01 С 1/00, 1988.

USSR author's certificate number 402736. class. G 01 S 1/00, 1972.

Finkelstein M.I. Basics of radar, - M .: Owls. radio, 1973, p. 402. (54) METHOD OF MEASURING ANGLES BETWEEN DIRECTIONS FOR REFLECTORS

(57) Use; for measuring angles between points equipped with reflectors. SUMMARY OF THE INVENTION: By means of an electromagnetic radiation source 1, a directed beam is formed; this beam is rotated.

in the measurement plane with the shaft 7, on which the radiation receiver 2 and the angle sensor 3 are fixed. The beam is modulated with the help of block 5 by a frequency multiple of the coefficient to the pulse frequency of the sensor 3. The pulses of the modulated beam are synchronized with the pulses of the sensor 3. Reflected from the reflectors register with receiver 2 and record the number of pulses, ne and ff of reflected rays from each of the reflectors e and t. Measured

angle is determined by the expression ftcm - K

(N K-0.5ng. + 0.5nm), where a is the angular magnitude of one pulse of the angle sensor 3; N is the number of counting pulses of the sensor 3 for the period of time between the moments of registration of the rays reflected from the reflectors. {il

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The invention relates to an optical instrument, mainly geodesic, and can be used in measuring angles between objects equipped with reflectors.

Methods are known for measuring the angles between reflectors when determining the coordinates of an object in which a beam of light successively illuminates the reflecting zones, receive reflected signals, record the time interval between reflected signals and the speed of a circular deployment of a beam of light. The disadvantage of these methods is the need for highly accurate stabilization of the rotation speed of the goniometer and equality of the angular dimensions of the reflectors.

One of the chronometric methods involves deploying the beam in the forward and reverse directions, and the calculations are performed over the time intervals of the forward and reverse deployment. This allows to obtain angles between the directions to the centers of the reflectors, regardless of their angular dimensions, but more than doubles the time required for measurements. In addition, measurement errors, as in other chronometric methods, depend on the stability rotation speeds.

A method of measuring coordinates, which is also widely used in radar, is known, in which by circular deployment of reflecting objects one takes

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the reflected radiation and record the number of signals from the rotary device angular position sensor between the moments of registration of reflected rays and calculate the measured angle taking into account the angle of one counting interval between adjacent angles of the angle sensor. To take into account the angular magnitude of the reflecting object, the angles are measured before the onset of the reflected signals and until the reflected signals cease and take an arithmetic average from them. Unlike chronometric methods, stabilization of the rotational speed is not required, i.e. counts are made on the pulses of the angle sensor associated with the angle, and not the time of rotation of the axis of rotation.

However, with direct transfer of the method to the optical range, a high accuracy of the angle measurements is not ensured. This is due to the fact that the accuracy of fixing directions in the radio range is lower than the accuracy of angle-of-turn sensors, while in the optical range the accuracy of fixing directions can be much higher.

The aim of the invention is to improve the accuracy of measuring the angles between the directions to the reflectors when using the radiation of the optical range.

The invention consists in improving the known method of measuring angles using axis angle sensors, fixing the number of counting pulses N between the moments of registration of reflected rays and calculating the measured angle fym taking into account the angular value and one counting pulse of the angle sensor.

The difference from the known method is that the emitted rays modulate a frequency that is a multiple of the coefficient K of the frequency of the pulses of the angle-of-turn sensor, and the pulses of the modulated beam are synchronized with the pulses of the of the angle-of-turn sensor. When registering the reflected rays record the number of pulses u and nm reflected rays from each of the reflectors. The angle between directions is found from the expression:

Am Ј (N K-0.5nt + O.Snm). TO

The drawing shows the possible scheme of the device that implements the method. On it are marked: light source 1. photodetector 2, angle sensor 3, drive 4, frequency multiplying unit 5, counting unit 6, axis of rotation 7 Drive 4 axis of rotation 7 is connected to the angle sensor 3 installed on one shaft 2 and the light source 1. The output of the photodetector 2 is connected to the first input of the counting unit 6. The output of the rotation angle sensor 3 is connected to the input of the frequency multiplier 5, the output of which is connected to the second input of the counting solving unit 6 and to the light source 1.

The measurements according to the described method are carried out as follows. After switching on the drive 4, the rotation of the light source 1, the photodetector 2 and the rotation angle sensor 3 starts. The signals of the rotation angle sensor 3 enter the frequency multiplying unit 5 and the radiation of the light source 1 is modulated. Due to the rotation of the light source 1 consecutive illumination of reflector areas not shown in the figure. When light hits the first reflector, the reflected radiation is received by the photodetector 2, which rotates simultaneously with the light source 1. From this moment on, the counting unit 6 begins to fix the signals from the first reflector rig.

At the same time, the fixation of the number of signals N of the angle sensor 3 begins. The fixation of these signals can also begin from the moment the signals from the reflector cease. As the shaft rotates on, the number of these signals continues. When the second reflector located at another point is illuminated, signals from the second reflector nm are received from the photodetector 2 and recorded in the counting unit 6. Simultaneously with the arrival of the initial (or final) signal from the reflector, the fixation of the number of signals of the angle sensor 3 stops. The fixed signals in the counting-decider unit b allow calculating the angle when entering data on constant values (t and K and signs, assigned to the signals of the rig and nm depending on whether the counting signal N begins and ends with the reflectors' initial or final signals.

The chronometric and described methods have the requirement of stable rotational speed, but in chronometric it extends to the full rotation of the shaft, and in the described method only to the interval between the pulses of the angle sensor, Due to the synchronization of the pulses of the modulated beam and the pulses of the angle sensor and multiplying the frequency

sensor K times the measurement accuracy.

Claims (1)

Accounting for the number of signals arriving from reflectors allows one to obtain measurement results from a single rotation of the device operating in accordance with the described method. Claims The method of measuring angles between directions to reflectors, at which a directional beam of electromagnetic radiation is formed, rotates this beam in the measurement plane, records the rays reflected from the reflectors, fixes the number of counting pulses N from the angle sensor of the beam five beams and calculate the measured angles / j сm taking into account the angular value a of one counting pulse of the angle sensor, characterized in that. In order to increase accuracy, the beam is modulated with a frequency multiple of the coefficient K of the pulse frequency of the angle-of-turn sensor, synchronizes the pulses of the modulated beam and the pulses of the angle-of-turn sensor; angle is found from the expression / V 7 (-N K 0 5rV + 0.5nm)