JPH058392B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Technical Field of the Invention The present invention divides infrared rays emitted from a target into a plurality of wavelength bands, and determines the output difference value of each wavelength band and propagation according to environmental conditions. This relates to an infrared distance measuring device that measures the distance to a target using constants.

(b) Background of the technology Generally, navigation systems such as radar, Loran, and Detsuka are used as ranging devices to measure the distance to a target. The former radar distance measurement method receives emitted radio wave signals and measures the distance to the target based on the time it takes. This radar distance measurement method has the disadvantage that a third party can learn of your location through the emitted radio wave signal. Further, the ranging method of the navigation system is a large-scale system that requires a plurality of transmitting devices and a spatially spread out arrangement.

Therefore, a distance measuring method using an infrared distance measuring device is attracting attention because it can eliminate the drawbacks of the above-mentioned radar distance measuring method and navigation system distance measuring method.

(c) Prior art and problems Distance measurement using a conventional infrared distance measuring device is shown in Figure 1a.
As shown in the layout diagram of the infrared range finder, the two infrared range finders 2 and 3 are separated by a predetermined distance w, and the infrared range finder 2 is placed at the same position as the infrared range finder 3. Target 5 and target 1 can be displayed, and infrared range finder 3 is arranged so as to be able to display target 4 and target 1, which are placed at the same position as infrared range finder 2.

The construction of the infrared distance measuring devices 2 and 3 is shown in the block diagram of FIG. 1b. That is, the infrared rays emitted from the target object are caught by the condenser mirror 6 and input to the infrared detector 7. The input infrared rays are converted into electrical signals by the infrared detector 7. The converted electrical signal is amplified by an amplifier 8 and displayed on a display 9. The infrared detector 7 used in the infrared distance measuring devices 2 and 3 is composed of multiple elements, and displays the target within the field of view of the condenser mirror 6 as an image on the display 9.

The display 9 of the infrared distance measuring device 2 displays the target 1 shown in FIG. 1a and the target 5 of the infrared distance measuring device. Therefore, from the displayed image, the azimuth angle θ1
Measure. Similarly, the display 9 of the infrared range finder 3 displays target 1 and target 4 of the infrared range finder shown in FIG. 1a. The azimuth angle θ2 is measured from the displayed image. Next, the distance between the infrared range finder 2 and the target 1 and the distance between the infrared range finder 3 and the infrared range finder 3 are determined based on the measured azimuths θ1 and θ2 and a predetermined distance w between the infrared range finders 2 and 3. The distance to the target 1 is calculated, and the distance to each infrared distance measuring device is measured.

As mentioned above, this conventional distance measurement method requires two infrared distance measurement devices, and requires the placement of the infrared distance measurement devices at positions separated by a predetermined distance, and the distance measurement method based on the displayed image. The drawbacks were that the calculations were done manually, which was time-consuming and required a lot of effort.

(b) Purpose of the Invention The present invention was devised in view of the above-mentioned drawbacks of the conventional infrared distance measuring device, and its purpose is to use an infrared distance measuring device to measure and display the distance between targets using a single infrared distance measuring device. The purpose of the present invention is to provide a distance measuring device.

(e) Structure of the Invention According to the present invention, this object is to provide an infrared distance measuring method in which the distance to the target object is measured by receiving infrared rays emitted from a target object with an infrared detector and converting the received infrared rays into an electric signal. In the apparatus, a plurality of spectral filters that separate infrared rays from a plurality of points having different temperatures on the target object into different specific wavelength bands and output the separated infrared rays, and a space between the target object and the plurality of spectral filters. a storage unit that stores in advance environmental conditions of a plurality of propagation paths formed by the spectral filters and propagation constants set between specific wavelength bands of each spectral filter; and a calculation unit that calculates the distance to the target object; A plurality of output difference values obtained by converting any two of the infrared rays output from each spectral filter into electrical signals and a propagation constant sent from the storage section are added to the calculation section to calculate the distance between the target object and the target object. This is achieved by an infrared distance measuring device characterized by measuring the distance of .

(f) Embodiment of the invention An embodiment of the invention will be described below with reference to the accompanying drawings.

FIG. 2 is a block diagram of an infrared distance measuring device according to the present invention, and the same reference numerals as in FIG. 1 indicate the same parts. That is, the configuration of the infrared distance measuring device of the present invention is such that two points 1A and 1 of the target object 1 having different temperatures are arranged.
B For example, if the target object is a ship, there is a condenser mirror 6 that captures infrared rays emitted from two points, the engine section and the hull, and a spectroscopic filter 10A that splits the captured infrared rays into two wavelength bands in this embodiment. 10B
a switching circuit 11 that performs a switching operation so as to alternately input infrared rays in two wavelength bands separated by the wideband infrared detector 12; and a switching circuit 11 that converts each infrared ray switched by the switching circuit 11 into an electrical signal. A broadband infrared detector 12, an amplifier 8 that amplifies the electrical signals in two wavelength bands output from the broadband infrared detector 12, and a display 9 (not shown) that displays the electrical signals output from the amplifier 8.
Further, a distance measurement calculation is performed using the output difference value of the electric signals in the two wavelength bands amplified by the amplifier 8 and a propagation constant that is stored in the storage section 13B and set in advance in accordance with the environmental conditions to be sent out. It consists of a section 13A and a distance display section 14 that displays the measured distance value calculated by the calculation section 13A.

In its operation, first, the condenser mirror 6 captures infrared rays emitted from two points in the target object having different temperatures, that is, two points 1A and 1B where there is a temperature difference ΔT. Next, the infrared rays 1A and 1B captured by the condenser mirror 6 are separated into a plurality of wavelength bands by a plurality of spectral filters having different passbands. In the example, spectroscopy was performed using spectroscopic filters 10A and 10B having passbands of 3 microns and 10 microns. Infrared signals emitted from two points 1A and 1B are filtered through spectral filter 1.
Targets 1A and 1B are separated by 0A and 10B.
2 emitted from the spectral filter 10A and passed through the spectral filter 10A.
This results in four infrared signals: one infrared ray and two infrared rays emitted from the targets 1A and 1B and passed through the spectral filter 10B. These four infrared signals are controlled by a switching circuit and are sequentially transmitted to the broadband infrared detector 1.
2 and each is converted into an electrical signal. This converted electrical signal is amplified by an amplifier 8, and its output signal is displayed on a display 9 and is also input to a calculation section 13 according to the present invention. Calculation section 13
A is the output voltage of the amplifier 8. The calculation unit 13A is the output voltage of the amplifier 8. The output voltage difference ΔTin1 of the two infrared rays emitted from the targets 1A and 1B and passed through the spectral filter 10A and the targets 1A and 1B.
2 emitted from the spectrum filter 10B and passed through the spectral filter 10B.
The output voltage difference ΔTin1 of the two infrared rays and the storage section 13B
The value corresponds to the infrared wavelength band emitted from targets 1A and 1B, and is stored and output in the infrared wavelength band emitted from targets 1A and 1B, depending on the wavelength band and the environmental conditions at the time of distance measurement, such as rain, fog, water vapor, aerosol, etc. The distance between the targets is calculated using propagation constants σ1 and σ2 corresponding to the unit attenuation of each propagation path set in advance. This calculated value is displayed on the distance display section 14.

The operation of the signal processing section 13 of the infrared distance measuring device of the present invention is based on the following basic principle. That is, the infrared rays emitted from the target 1A are separated into two wavelength bands by the spectroscopic filters 10A and 10B, and the output voltage difference ΔTin1 obtained by separating the infrared rays emitted from the targets 1A and 1B by the spectroscopic filter 10A is Similarly, the output voltage difference ΔTin2 obtained by dispersing the infrared rays emitted from the targets 1A and 1B with the spectroscopic filter 10B is proportional to the temperature difference ΔT between the two points of the targets 1A and 1B, and its propagation This uses the property of being exponentially inversely proportional to the distance D, and the following formula is known.

ΔTin1=ΔTexp(−σ1×D) ……(1) ΔTin1=ΔTexp(−σ2×D) ……(2) From equations (1) and (2), D=1/σ2−σ1×ln(ΔTin1 /ΔTin2)……(3) By setting the propagation constants σ1 and σ2 in the wavelength bands 10A and 10B in equation (3), the distance D to the target object can be calculated. Therefore, the values of the propagation constants σ1 and σ2, which change depending on environmental conditions such as rain, fog, water vapor, and aerosol, are set to values corresponding to various environmental conditions and are stored in the storage unit 13B. The storage unit 13B sends propagation constants σ1 and σ2 corresponding to the environmental conditions to the calculation unit 13A in response to a control signal representing the environmental conditions from the outside (not shown). The calculation unit 13A calculates the distance D to the target from equation (3) using ΔTin1, ΔTin2, σ1, and σ2.
is calculated, and the distance D to the target is displayed by the distance display unit 14.
Display.

(g) Effects of the Invention According to the present invention, there is an effect that the distance to a target can be easily measured using one infrared distance measuring device.

[Brief explanation of the drawing]

FIG. 1a shows a distance measuring arrangement of a conventional infrared distance measuring device, FIG. 1b shows a block diagram of the conventional infrared distance measuring device, and FIG. 2 shows a block diagram of an infrared distance measuring device according to the present invention. In the same figure, 1, 4 and 5 are targets, 1A and 1B
are targets with different temperatures, 2 and 3 are infrared range finders, 6 is a condenser, 7 is an infrared detector, 8 is an amplifier, 9 is a display, 10A and 10B are spectral filters, 11 is a switching circuit, 12 is a broadband infrared detector, 13 is a signal processing section, 13A is a calculation section, 13B
14 indicates a storage section, and 14 indicates a distance display section.

Claims (1)

[Claims] 1. An infrared distance measuring device that measures the distance to a target object by receiving infrared radiation emitted from a target object with an infrared detector and converting it into an electrical signal, comprising: A plurality of spectral filters that separate infrared rays from different points into different specific wavelength bands and output the separated infrared rays, and a plurality of propagation paths formed between a target object and the plurality of spectral filters. A storage unit that stores in advance environmental conditions and propagation constants set between specific wavelength bands of each spectral filter, and a calculation unit that calculates the distance to a target object are provided, and the infrared rays output from each of the spectral filters are A plurality of output difference values obtained by converting any two of them into electrical signals and a propagation constant sent from the storage section are added to the calculation section to calculate the distance between the target object and the infrared distance measuring device. An infrared distance measuring device characterized by: