SU900189A2 - Corelation meter of speed - Google Patents

Description

one

The invention relates to instrumentation, namely, devices intended for determining the speed and distance traveled by moving objects and can be used, for example, to measure the speed of rolling and to navigate aircraft.

According to the main auth. No. 4b6 53 a correlation velocity meter is known that contains two input limit amplifier amplifiers, the outputs of the first of which are connected to the inputs of the first and second shift registers, and the outputs of the second with the first inputs of combined coincidence and subtraction circuits, the second and third inputs of which are connected respectively with the intermediate and last cells of the first and second shift registers, the first output of the first combined coincidence and subtraction circuit is connected to the first input of the first OR circuit, the second input of which is connected to the second output the house of the second combined coincidence and - combination, and the first output of the second combined coincidence and subtraction scheme is connected to the first input of the second OR circuit, the second input of which is connected to the second output of the first combined coincidence circuit and subtraction, the outputs of the OR circuit are connected to the integrator, the output of which connected to

10 oscillator clock pulses connected to its output, with the inputs of the advancing pulses of the shift registers and the input of the counter 1P.

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However, the accuracy of the known correlation velocity meter is limited by methodical and instrumental errors and amounts to one order of doppler. This leads to measurement errors of speed and distance traveled.

The purpose of the invention is to improve the measurement accuracy. 3 9 The goal is achieved by addition of a signal converter, a circuit for switching on a register of a current map of a terrain and a choice of a reference map of a terrain, a register of a current map of a region, a memory block of a reference map of a map, a map processing circuit, a pulse divider. the clock frequency and the path correction circuit, while the input of the second limiting amplifier is connected to the signal inputs of the register through a signal converter and a circuit for switching on the register of the current terrain map the local map, the inputs of the pushing pulses that are connected through a frequency divider to the clock input of the clock generator, the output of the register of the current terrain map is connected to the first input of the card processing circuit, the second input of which is connected to the output of the memory block of the reference terrain map, and its output - to the path correction circuit, the output of which is connected to the correction input of the track estimator, and its output is connected to the switching inputs of the circuit for switching on the register of the current map of the region and the circuit for selecting a reference map of the area, cat outputs The station is connected to the memory block of the reference area map. FIG. 1 shows the functional scheme of the device; in fig. diagram. The device includes two limiter amplifiers 1 and 2, two separate registers 3 and t shift, combined circuits 5 and 6 coincidence and subtraction, circuit OR 7 and 8, integrator 9) d clock oscillator, 10 pulses, 11 pulse counters, converter 12 signals, turn-on circuit 13, circuit AND selection of a reference map of the terrain, divider 15 clock frequency, register 16 of the current terrain map, memory block 17 of the reference terrain map, card processing circuit 18 path correction circuit 19. The outputs of the first amplifier-bounding bodies 1 are connected to the inputs of the first 3 and second 4 shift registers. The outputs of the second amplifier-limiter are connected to the first inputs of the combined circuits 5 and 6 of coincidence and subtraction, the second and third inputs of which are connected by the corresponding intermediate and last cells of the first 3 and second k shift registers. The first output of the first combined coincidence and subtraction circuit 5 is connected to the first input of the first OR circuit 7, the second input of which is connected to the second output of the second combined coincidence and subtraction circuit 6. The first output of the second combined circuit 6 of coincidence and subtraction is connected to the first input of the second circuit OR 8, the second input of which is connected to the second output of the first combination circuit 5 of matching and subtraction. The outputs of the OR circuits 7 and 8 are connected to the integrator 9, the output of which is connected to the generator of 10 clock pulses, connected by its output to the inputs of the advancing pulses of registers and 3 shifts, the input of the counter 11 and the input of the divider 15, through the signal converter 12 and the circuit 13 with the signal input of the register 1b of the current terrain map, the inputs of the advancing pulses of which are connected to the output of the frequency divider 15. The output of the register 16 of the current terrain map is connected to the first input of the card processing circuit 18, the second input of which is connected to the output of the memory block 17 of the reference terrain map, and its output to the path correction circuit 19, its output connected to the correction input of the pulse counter 11. The output of pulse counter 11 is connected to the switching inputs of the switching circuit 13 and the selection circuit of the reference area map, the outputs of which are connected to the memory block 17 of the reference area map. The device works as follows. Two arbitrary waveforms x (t) and x (t-t-Lr), which are shifted by the value of the transport delay, arrive at the meter input. Amplifier suppressors convert these signals into signum signals sign (x (t) and 5 ign X i ttC)., Corresponding to the positive polarity of the input signals, at the output a-sign2, x (t) and 5 (t-1-T) corresponding to the negative polarity of the input signals at the output of & . Signal signals are fed to the inputs of registers 3 and k, where these signals are time-quantized with a generator frequency of 10 clock pulses and delayed by the time determined by the pulse frequency. Since the outliers of the original signal cannot exist simultaneously, the inputs of the OR 7 and 8 circuits receive pulses from the first outputs of the coincidence circuit. OR schemes ensure the operation of both channels on a single integration scheme. In case of equality of the signal delay in the registers to the transport delay, the number of pulses arriving at the integrators is the same and the frequency of the oscillator is constant and equal to the given one. With undercompensation, the ratio of the number of pulses to the OR circuits is changed so as to bring the correlator to an equilibrium state. The pulse frequency is a measure of speed, and the total number of pulses, accumulated by counter 11, is the path traveled by the object. To perform the path correction, the current terrain map is taken during the flight over the selected section. One of the sensor signals, for example xlt + t), is fed to the input of the inverter 12, the output of which is separated by a voltage proportional to the measured physical parameter. As this parameter, the luminance factor, the reflection coefficient or the height of the elevation profile is used. The output of the converter 12 through the switch 13 is connected to the input of the register 1b of the current terrain map. The correction section is selected when the object is moved over the contact area of the underlying surface to which x (Fig. 2). In the switching circuit 13, the programmed correction path values x, x, and are entered. Its second input is supplied with the current -th value of the traversed path x from scheme 11. If the measured and software ranges are equal, the circuit 13 switches the output of the converter 12 to the register 16 of the current terrain map, in which the values of the parameters of the current terrain map are recorded. The propulsive pulses of register 1 of the current terrain map are formed from clocks; the correlator of a torus by pressure of their frequency a certain number of times equal to K. It is defined by the ratio of the longitudinal size of the reflecting area a to the price of the range pulse So 2Ht9 where H is the height of the sensors (optical or radio) above the surface; beam width i. the base between the receiving antennas (optics) of the sensors is the average number of working cells of the 3 registers or k correlator. This ensures that the current map is recorded in the 16 register of the current terrain map 3 as a sequence of independent samples. To record the current terrain map, the 10 clock pulse generator output through the frequency divider 15 is connected to the register 16 of the current terrain map. The current card is recorded before the register is filled. Simultaneously with the beginning of the recording of the current map, the counter 11 outputs a signal to the circuit 1 for selecting a reference map of the area. The reference maps of the area recorded for each correction area are stored in the memory unit 17. The map processing circuit 18 compares the current terrain map and the terrain reference map by shifting them relative to each other. In this case, any of the methods of correlation processing of digital maps can be used. The deviation of the x coordinate relative to the program point Hc is determined by the required shift of the current terrain map relative to the reference terrain map — by the number of cells N, which corresponds to the linear deviation AX., N This value is entered into the path correction circuit 19, through which the corrected path value is output, the measured score - 1J. The invention with the proposed aircraft path correction devices can provide increased navigation languor compared with the known correlation velocity meter.

Claims (1)

1. USSR author's certificate №, cl. G 01 R B / B, 1975. X l