JP4725913B2 - Snowfall intensity measuring method and snowfall intensity measuring apparatus - Google Patents

Description

  The present invention relates to a snowfall strength measuring method and a snowfall strength measuring device used for, for example, weather observation and automatic control of a snowmelt device.

Conventionally, as a snowfall intensity measuring device of this type, a detection pulse from a sensor unit having a so-called reflective structure in which measurement light is projected from a light projecting unit to a detection space and light reflected from a snowflake is received by a light receiving unit. There is known a structure that counts the number of snowfalls and calculates and measures snowfall intensity based on the number of detected pulses.
Japanese Patent Publication No. 4-23740

  However, in the case of the above conventional structure, since the sensor is a reflective structure, the detection area is located in front of the sensor unit, so the size of the sensor part can be reduced, and the manufacturing cost can be reduced, In addition, the sensor can be easily installed and the installation flexibility can be improved. On the other hand, in the case of a sensor with a reflective structure, it is detected by the size of the snowflake to be measured and the moving speed of the snowflake. Detects the number of snowflakes per unit time in a certain area because the distance characteristic changes greatly, the detection area becomes ambiguous due to the change in the detection distance characteristic, and the detection area becomes ambiguous. Cannot be quantified, that is, it may not be possible to measure the ever-changing snow intensity. That.

  The present invention aims to solve these disadvantages. Among the present inventions, in the method invention according to claim 1, the projection light is projected from the light projecting portion to the detection space, and A plurality of sensor units having a structure in which the reflected light from the snowflake of the projected light is received by the light receiving unit are provided, and the detection areas of the sensor units overlap the optical axes of the light projecting units of the plurality of sensor units. The sensor units are arranged in an intersecting manner, and the detection operation of each sensor unit is performed in an independent state without mutual interference, and the logical product of each detection pulse from each light receiving unit of the plurality of sensor units is calculated. Output and count the number of AND pulses obtained by AND operation, and based on the number of AND pulses obtained by AND operation and the size of the overlap detection area where the detection areas of the sensor units overlap. In snowfall intensity measurement method characterized by measuring the snowfall intensity Te.

  According to a second aspect of the present invention, there is provided a plurality of sensor units having a structure in which projection light is projected from the light projecting unit to the detection space and reflected light from the snowflake is received by the light receiving unit. The optical axes of the light projecting portions of a plurality of sensor units are arranged in an intersecting manner so that the detection areas of the sensor units overlap with each other, and the detection operations of the sensor units are configured in an independent state without mutual interference. AND means for calculating and outputting the logical product of the detection pulses from the light receiving portions of the plurality of sensor units, and counting the number of AND pulses subjected to the AND operation. Counting means, and calculation measuring means for calculating and measuring snowfall intensity based on the number of AND pulses obtained by the AND operation and the size of the overlapping detection area where the detection areas of the respective sensor units overlap. In snowfall intensity measuring apparatus characterized by comprising in Bei.

  According to a third aspect of the present invention, each of the detection means includes a power supply circuit, an oscillation circuit for oscillating and outputting a reference clock pulse, and timings for generating various timing pulses from the reference clock pulse. A generation circuit, a light projecting drive circuit for driving the light projecting unit with a light projecting pattern based on the timing pulse, and a signal processing circuit for discriminating only a detection pulse synchronized with the timing pulse among the detection pulses from the light receiving unit And an output circuit that outputs a detection pulse at the time of the synchronization detection to the AND operation means. A temperature sensor for detecting temperature is provided, and the invention according to claim 5 is characterized in that the plurality of sensor units are installed. A wind rudder that turns the detector body in accordance with the direction of the wind so that the body can be swung horizontally and the wind blown to the detector body crosses the optical axis of the light projecting portion of the sensor unit as much as possible. A member is provided.

  As described above, according to the first or second aspect of the present invention, the projection light is projected from each light projecting portion of each of the plurality of sensor units to the detection space and the reflected light from the snowflake of the projection light is projected. Light is received by each light receiving unit, and the optical axes of the light projecting units of the plurality of sensor units are arranged in an intersecting manner so that the detection areas of each sensor unit overlap, and from each light receiving unit of each sensor unit, The AND of the detected pulses is calculated by the AND operation means and an AND pulse is output. The number of AND pulses obtained by the AND operation is counted by the counting means. Based on the size of the overlapping detection area where the detection areas of the sensor unit overlap, for example, the area of the overlapping detection area, the snowfall intensity is calculated and measured by the calculation measuring means. By forming an overlap detection area that overlaps the detection area of the knit, it is possible to specify the detection area, and it is possible to detect only snowflakes in the overlap detection area that is the specified detection area, and to quantify the snowfall intensity Since each sensor unit is equipped with detection means configured to be able to improve the measurement accuracy and the measurement accuracy, and the detection operation of each sensor unit is performed in an independent state without mutual interference, each detection is performed for each sensor unit. Pulses can be detected, accurate detection pulses can be obtained, and snowfall intensity measurement accuracy can be increased.

  In the invention according to claim 3, each of the detecting means generates a power supply circuit, an oscillation circuit for oscillating and outputting a reference clock pulse, and various timing pulses from the reference clock pulse. Signal processing for discriminating only the detection pulse synchronized with the timing pulse among the detection pulses from the timing generation circuit, the light projecting drive circuit that drives the light projecting unit with the light projection pattern by the timing pulse, and the light receiving unit Circuit, and an output circuit that outputs a detection pulse at the time of synchronization detection to the AND operation means. Therefore, by generating a timing pulse having a different frequency by the timing pulse generation circuit or by generating a timing pulse having a different frequency by each timing generation circuit. The detection operation of each sensor unit can be performed reliably in a non-interfering and independent state, improving measurement accuracy. In the invention according to claim 4, since the calculation and measurement means is provided with a temperature sensor for detecting the outside air temperature, it is possible to perform rain / snow discrimination more accurately, In a fifth aspect of the present invention, the detector body including the plurality of sensor units is disposed so as to be horizontally rotatable, and the wind blown to the detector body changes the optical axis of the light projecting portion of the sensor unit. Since the wind direction steering member that turns the detector body according to the wind direction is provided so as to cross as much as possible, even if the snowflake moving at the same speed passes through the detection area at different angles depending on the wind direction, the transit time will be different As a result, the AND pulse may not be generated, but the detector body is swung according to the direction of the blowing wind by the wind direction rudder member, and is swung so as to cross the optical axis of the light projecting unit as much as possible. So to improve the measurement accuracy It can be. Measurement accuracy of snowfall intensity can be improved.

  FIGS. 1 to 6 show an embodiment of the present invention. A / B includes a plurality of sensor units, in this case, two sensor units. The projection light R is projected from 1 and the reflected light R from the snowflake D of the projection light R is received by the light receiving unit 2.

In this case, in FIGS. 1, 2, 6, the upper end of the tower G to be erected on the ground mounting the mounting cylinder K ₁ of the detector body K, the detector body K of each sensor unit A · B The optical axis of the light projecting unit 1 is arranged in an intersection so that the detection areas of the sensor units A and B overlap each other, and the overlapping detection area W in which the detection areas of the sensor units A and B overlap by this intersection arrangement. Try to form.

  The light projecting unit 1 includes a light emitting element 1a such as a light emitting diode (LED) or a laser diode (LD), and the light receiving unit 2 includes a light receiving element 2a such as a phototransistor (PTr) or a photodiode (PD). Built in.

  In this case, the optical axes of the light projecting units 1 and 1 of the two sensor units A and B are arranged in an intersecting manner so that the detection areas of the sensor units A and B overlap.

  Reference numerals 3 and 3 denote detection means, which are configured such that the detection operations of the sensor units A and B are performed in a non-interfering and independent state.

  Reference numeral 4 denotes a logical product calculation means, which calculates the logical product of the detection pulses from the light receiving units 2 and 2 of the two sensor units A and B as shown in FIGS. Is a circuit that outputs.

  Reference numeral 5 denotes a counting means, which is a circuit for counting the number of AND pulses subjected to the AND operation.

  6 is an arithmetic measurement means, which is a circuit for calculating and measuring snowfall intensity based on the number of AND pulses obtained by the AND operation and the size of the overlapping detection area W where the detection areas of the sensor units A and B overlap. It has become.

For example, assuming that the number of AND pulses = N [pieces] and measurement time = t [minutes],
Snowfall intensity per hour = R (assuming that the AND pulse detected at the measurement time t continues for one hour)
R = 60 · k · n / (S · t)
R = Snowfall intensity converted to precipitation [mm / h]
k = mass parameter of snowflakes ≒ snowflake density [mm / puls] (equivalent amount of precipitation per snowflake)
S = Projected area [cm ² ] of the overlap detection area W as seen from the direction of the snowflake flow
Will be required.

  In this case, the arithmetic and measuring means 6 is provided with a temperature sensor 7 such as a thermistor thermometer for detecting the outside air temperature. That is, for example, if the set temperature is set to 0.3 ° C or less as snow, and the above is set as rain, the rain / snow discrimination is set. It is configured to calculate and measure snowfall intensity.

  In this case, as shown in FIGS. 2 and 3, each of the detection means 3 includes a power supply circuit 3a, an oscillation circuit 3b that oscillates and outputs a reference clock pulse, and timings for generating various timing pulses from the reference clock pulse. A generation circuit 3c, a light projecting drive circuit 3d for driving the light projecting unit with a light projecting pattern based on timing pulses, a disturbance light removing circuit 3e for removing disturbing light from the light receiving unit 2, and a light from the light receiving unit 2 It comprises a signal processing circuit 3f that discriminates only detection pulses that are synchronized with the timing pulse among the detection pulses, and an output circuit 3g that outputs a detection pulse at the time of synchronization detection to the AND operation means 4.

  That is, in FIG. 3, FIG. 4, and FIG. 5, the oscillation circuits 3b and 3b of the sensor units A and B charge and discharge the built-in capacitors with a constant current, so that the reference clock pulse has a specific frequency (fa). The oscillation output is output at a frequency (fb), and this oscillation output is input to the timing generation circuit 3c to generate a light projecting unit driving pulse and various timing pulses for digital signal processing. The light projecting drive circuit 3d performs light projection driving of the LED of the light projecting unit 1 with a predetermined duty ratio by the light unit driving pulse, and the light of the light projecting unit 1 is predetermined light projected by the light projecting driving circuit 3d. The projected light is flashed and projected in a pattern, and the reflected light from the snowflake D of the projected light is received by the light receiving unit 2, and the on-chip photodiode of the light receiving unit 2 is received by receiving the reflected light. A photocurrent is generated, this photocurrent is converted into a voltage by the preamplifier circuit of the disturbance light removal circuit 3e, and the dynamic range for the DC and low frequency disturbance light is expanded by the AC amplifier circuit of the preamplifier circuit and the signal detection sensitivity In addition, low-frequency disturbance light is removed by C coupling, DC offset of the preamplifier part is removed at the same time, and further, it is amplified to the comparator level by the buffer amplifier circuit, and the comparator level signal is output by the reference voltage generation circuit. The hysteresis function of the comparator circuit prevents chattering due to slight fluctuations in the input light, and the signal processing circuit 3f is composed of a gate circuit and a digital integration circuit. This gate circuit is a detection pulse from the light receiving unit 2. Generated by the timing generation circuit 3c. Only the detection pulse synchronized with the timing pulse is discriminated, malfunction caused by asynchronous disturbance light is prevented, the synchronous disturbance light is removed by the digital integration circuit, and the output circuit 3g outputs the detection pulse at the time of synchronization detection to the AND operation means 4. Will be output.

  Thus, the inherent frequency (fa) and frequency (fb) of the clock pulse serving as a reference for the detection circuits 3 and 3 are different, or are different from each other generated by the timing generation circuits 3c and 3c. The detection operation of each of the sensor units A and B is configured to be performed in an independent state without mutual interference by the frequency timing pulse.

Further, in this case, in FIG. 6, the detector body K is arranged freely horizontal turn by a bearing section K _2, the optical axis of the light projecting portion of the wind blows on the detector body K is the sensor unit A · B A wind steering member M that turns the detector body K according to the wind direction F is provided so as to cross as much as possible.

  Since this embodiment is configured as described above, the projection light R is projected from each of the light projecting units 1 and 1 of each of the sensor units A and B in the detection space, and in this case, the projection light R The reflected light R from the snowflake D is received by the light receiving units 2 and 2, and the optical axes of the light projecting units 1 and 1 of the two sensor units A and B are detected by the detection regions of the sensor units A and B. Are arranged so as to overlap each other, and the logical product of the detection pulses from the light receiving units 2 and 2 of the two sensor units A and B is calculated by the logical product calculation means 4 to output an AND pulse. The number of AND pulses obtained by the logical product operation is counted by the counting means 5, and the number of AND pulses obtained by the logical product operation and the size of the overlapping detection region W where the detection regions of the sensor units A and B overlap, For example, based on the area of the overlap detection region W The snowfall intensity is calculated and measured by the arithmetic measurement means 6, and therefore, the detection area can be specified by forming the overlapping detection area W where the detection areas of the two sensor units A and B overlap. It is possible to detect only the snowflake D in the overlapping detection region W that is the specified detection region, to facilitate the quantification measurement of the snowfall intensity and to improve the measurement accuracy, and to detect the sensor units A and B. Since the detection means 3 and 3 are configured so that the operation is performed in an independent state without mutual interference, each detection pulse can be detected separately for each sensor unit A and B, and an accurate detection pulse can be obtained. Can be obtained, and the measurement accuracy of the snowfall intensity can be increased.

  It should be noted that a smooth surface such as raindrops is transmitted or totally reflected, and the snowflakes are irregularly reflected. Therefore, the frequency of returning to the light receiving unit 2 is extremely low in the case of raindrops. Due to the difference in reflection structure, it is unlikely that rain will be erroneously detected as snow, and snowflakes D outside the overlap detection area W may be detected accidentally at the same time, but the number is extremely small. It is considered that the strength measurement accuracy is not lowered.

  In this case, each detection means 3 includes a power supply circuit 3a, an oscillation circuit 3b that oscillates and outputs a reference clock pulse, a timing generation circuit 3c that generates various timing pulses from the reference clock pulse, A light projecting drive circuit 3d for driving the light projecting unit with a light projecting pattern by a timing pulse, and a signal processing circuit 3f for discriminating only a detection pulse synchronized with the timing pulse among the detection pulses from the light receiving unit 2, Since it comprises an output circuit 3g that outputs a detection pulse at the time of synchronization detection to the AND operation means 4, the difference between the inherent frequency (fa) and frequency (fb) of the clock pulse or the difference depending on each timing generation circuit The detection operation of each sensor unit A and B is confirmed in a non-interfering and independent state by generating frequency timing pulses. In this case, the calculation / measurement means 6 is provided with the temperature sensor 7 for detecting the outside air temperature, so that rain / snow discrimination can be performed more accurately. In this case, the detector body K including the two sensor units A and B is disposed so as to be horizontally rotatable, and the wind blown to the detector body K is projected by the sensor units A and B. Since the wind steering member M for turning the detector body K according to the wind direction is provided so as to cross the optical axis of the parts 2 and 2 as much as possible, even the snowflake D moving at the same speed is assumed to have different angles depending on the wind direction. When passing through the detection area, the transit time will be different, and an AND pulse may not be generated. However, the detector body K is swung according to the direction F of the blowing wind by the wind direction steering member M, and is projected. Cross the optical axis of parts 2 and 2 as much as possible Since pivots, it is possible to increase the measurement accuracy.

  The present invention is not limited to the above-described embodiment, but includes the sensor units A and B, the light projecting unit 1, the light receiving unit 2, the detection unit 3, the logical product calculation circuit 4, the counting unit 5, and the calculation measurement unit 6. The structure and the like are designed with appropriate changes.

  As described above, the intended purpose can be sufficiently achieved.

It is explanatory drawing of the detection state of the embodiment of this invention. It is a system configuration block diagram of an embodiment of the present invention. It is a systematic block diagram of the detection means of the embodiment of the present invention. It is explanatory drawing of the example of embodiment of this invention. It is explanatory drawing of the example of embodiment of this invention. It is a perspective view of the example of an embodiment of the invention.

Explanation of symbols

A sensor unit B sensor unit D snowflake K detector body W overlap detection area M wind steering member F wind direction G support 1 light projecting unit 2 light receiving unit 3 detection means 3a power supply circuit 3b oscillation circuit 3c timing generation circuit 3d light projecting drive circuit 3e Disturbance light removal circuit 3f Signal processing circuit 3g Output circuit 4 AND operation means 5 Counting means 6 Arithmetic measurement means 7 Temperature sensor

Claims (5)

  A plurality of sensor units having a structure in which projection light is projected from the light projecting unit to the detection space and reflected light from the snowflake is received by the light receiving unit, and the light projecting units of the plurality of sensor units are provided. The plurality of sensor units are configured such that the optical axes are arranged in an intersecting manner so that the detection areas of the respective sensor units overlap, and the detection operations of the respective sensor units are performed in an independent state without mutual interference. And outputs the logical product of each detection pulse from each light receiving unit and counts the number of AND pulses obtained by the logical product operation, and the number of AND pulses obtained by the logical product operation and the detection area of each sensor unit are calculated. A snowfall intensity measuring method, wherein snowfall intensity is measured based on the size of overlapping overlap detection areas.   A plurality of sensor units having a structure in which projection light is projected from the light projecting unit to the detection space and reflected light from the snowflakes is received by the light receiving unit, and the optical axes of the light projecting units of the plurality of sensor units; Are arranged in a crossing manner so that the detection areas of the sensor units overlap with each other, and detection means configured so that the detection operations of the sensor units are performed in a non-interfering and independent state are provided. AND unit for calculating and outputting the logical product of each detection pulse from each light receiving unit of the sensor unit, a counting unit for counting the number of AND pulses subjected to the AND operation, and the AND pulse subjected to the AND operation And a snowfall measuring means for calculating and measuring snowfall intensity based on the number and the size of the overlapping detection area where the detection areas of the respective sensor units overlap. Degree measuring device.   Each of the detection means includes a power supply circuit, an oscillation circuit that oscillates and outputs a reference clock pulse, a timing generation circuit that generates various timing pulses from the reference clock pulse, and a light projection pattern based on the timing pulse. A light projecting drive circuit for driving the light projecting unit; a signal processing circuit for discriminating only a detection pulse synchronized with the timing pulse among the detection pulses from the light receiving unit; and 3. The snowfall intensity measuring apparatus according to claim 2, further comprising an output circuit that outputs the product to the product calculating means.   The snowfall intensity measuring device according to claim 2 or 3, wherein the arithmetic and measuring means is provided with a temperature sensor for detecting an outside air temperature. The detector body having the plurality of sensor units is arranged in a horizontally swingable manner so that the wind blown to the detector body is directed in the direction of the wind so as to cross the optical axis of the light projecting portion of the sensor unit as much as possible. 5. A snowfall intensity measuring device according to claim 2, further comprising a wind rudder member that turns the detector body accordingly.

Images