JP7463698B2 - DETECTION APPARATUS, DETECTION SYSTEM AND DETECTION METHOD - Google Patents

Description

The present invention relates to an apparatus, system and method for detecting an object.

Sensing technology using infrared rays (also called infrared light) is known as a technology for detecting objects. Sensing methods using infrared rays include a method in which an object passes between an infrared emitting unit and a light receiving unit and detects whether or not the infrared rays are blocked, and a method in which infrared rays emitted from the light emitting unit are reflected by an object and detects whether or not the amount of light received by the light receiving unit changes (see, for example, Patent Documents 1 and 2).

However, with the former method, an object cannot be detected unless it passes through a point through which infrared light passes, so there must be multiple points through which infrared light passes, which necessitates multiple light-emitting and light-receiving units, resulting in a problem of increased cost.

On the other hand, the latter method only requires one pair of light emitter and receiver, as it monitors the change in the amount of light that is diffusely reflected within space and returned. Pests, one example of an object, come in a variety of sizes as they grow, and in order to distinguish between them, the ratio of the minimum to maximum change in light amount (dynamic range) must be large. However, if the dynamic range is made large, it becomes impossible to distinguish whether a small change in light amount is due to the size of the pest or an error, resulting in an increased number of detection errors.

The present invention has been made in consideration of the above, and aims to provide a device, system, and method that can be provided at low cost and reduce detection errors.

In order to solve the above-mentioned problems, one embodiment of the present invention provides an apparatus for detecting an object, the object being a pest,
A housing whose inner surface has a reflectance equal to or lower than a certain level;
A radiation means for radiating infrared rays into the housing;
A detection means for detecting infrared rays;
an adjustment means for adjusting an intensity of reflection of infrared light in response to a detection result of the detection means ;
A trap means is replaceably attached to the housing for trapping the pests;
a switch means for cutting off a power supply when the trap means is removed from the housing and for turning on a power supply when the trap means is attached to the housing;
Including ,
The adjustment means performs an initialization process each time the trap means is replaced, adjusting the reflection intensity of the infrared rays to a predetermined value when the object is not present within the housing .

The present invention can be provided at low cost and reduces detection errors.

FIG. 13 is a diagram showing the relationship between infrared detection value, temperature, and time. FIG. 2 is a diagram showing an example of the appearance of a detection device. FIG. 2 is a perspective view showing an example of the inside of a detection device. FIG. 2 is a plan view showing an example of the inside of a detection device. FIG. 1 is a cross-sectional view showing an example of a detection device. FIG. 1 is a diagram illustrating an example of a hardware configuration of a detection device. FIG. 2 is a block diagram showing an example of a functional configuration of a detection device. FIG. 4 is a diagram showing a configuration example of an emission unit included in the detection device. FIG. 2 is a diagram showing an example of the configuration of a detection unit included in the detection device. 10 is a flowchart showing an example of an initial calibration process executed by the detection device. FIG. 13 is a diagram showing an example of a table for managing calibration values after an initial calibration process. 13A and 13B are diagrams showing examples of different shapes of characteristic curves when the gain change range in the light receiving side characteristic curve is different. 11 is a flowchart showing a flow of preprocessing. 6 is a flowchart showing an example of a calibration process and a detection process that are executed at regular time intervals. FIG. 4 is a diagram showing an example of a table for managing calibration values to be referred to during frequency selection processing. 11 is a flowchart illustrating an example of a process executed by the detection device to transition from a provisional frequency to a determined frequency. FIG. 13 is a diagram showing an example of a table for managing calibration values when a provisional frequency is changed to a determined frequency. FIG. 13 is a perspective view showing another example of the inside of the detection device.

The detection device according to this embodiment is a device that uses infrared rays to detect objects, for example, a device that uses infrared rays to sense the detection of pests in a small space that is close to a closed space such as a pest trap. Note that in this embodiment, cockroaches are given as an example of an object to be detected, but the object to be detected is not limited to this.

The detection device emits infrared light from the emission section, and detects the changes in the infrared light that is reflected back within the space and reflected back from the pest when the pest is captured, to detect the pest capture status.

Here, we will explain the problems with detection devices that use this type of method. The reflected infrared light intensity, i.e., the amount of infrared light that is reflected back (amount of received light), needs to be adjusted so that the range in which the difference between when a pest is not caught and when it is caught is within the dynamic range of the infrared detection section. In particular, because pests grow in sizes ranging from small ones measuring in millimeters to large ones measuring in centimeters, a large dynamic range is needed to be able to detect the difference between them.

On the other hand, when detecting tiny pests on the order of millimeters, the change in light intensity is small, so if the dynamic range is increased, it becomes impossible to distinguish whether a small change in light intensity is due to a pest being caught or an error, resulting in more missed detections.

These errors include molding errors in the housing that forms the space for capturing pests, characteristic errors in the emission unit and detection unit, installation errors in the emission unit and detection unit, precision errors in the control unit (electronic circuits such as a CPU) that controls the emission unit and detection unit, and changes in the amount of light due to temperature changes. Of these errors, all but those caused by temperature changes are static errors inherent to the device.

Static errors can be reduced by performing correction before performing the detection process, improving the accuracy of pest detection.

In general, the LEDs (Light Emitting Diodes) used as the light source for the radiation section have the property that the amount of light decreases as the temperature rises and increases as the temperature falls. In addition, the output values of the electronic circuits and detection section also fluctuate with temperature changes. For this reason, it is necessary to take into account the temperature characteristics of the entire device. Temperature changes dynamically, and the change in light amount due to temperature change is sufficiently large compared to the change in light amount required to detect pests on the order of millimeters. Therefore, simply correcting for the static error described above before executing the detection process will result in numerous detection errors and make it impossible to accurately detect pests.

Figure 1 shows the relationship between infrared detection value and temperature and time during actual testing. The environmental temperature at the start of the test was set to 20°C, and adjustments (calibration) were performed to reduce static errors inherent to the device, so that the amount of reflected infrared light (amount of reflected infrared light received) as the detection value was set to a threshold value (0).

When the test begins, the temperature changes over time. In section 1, the temperature gradually drops while fluctuating up and down. The amount of light increases as the temperature drops. The temperature is returned to 20°C, and in section 2, the temperature gradually rises while fluctuating up and down. When the temperature rises above 20°C, the amount of light falls below the threshold. Note that in Figure 1, even when the amount of light is a negative value, it shows 0, so it is unclear whether it is actually a negative value.

When the temperature reaches 23°C (point A in the figure), an object measuring millimeters is inserted. Section 3 is the section in which the object is inserted and maintained in its inserted state without changing its position. When the object is inserted, the temperature fluctuates greatly up and down, but then the fluctuations gradually become smaller and the temperature begins to decrease.

In Figure 1, when the temperature is higher than 20°C, such as 23°C, the amount of light is below the threshold. On the other hand, when the temperature drops to around 20°C and approaches the environment in which calibration was performed, the amount of light increases. This is because when the temperature is higher than the calibration temperature of 20°C, the amount of light emitted from the light source of the emission unit decreases, and the amount of light reflected back from the object also decreases. For this reason, even if an object enters the area, the object cannot be detected unless the temperature returns to the calibration temperature of 20°C.

For these reasons, before executing the detection process, it is necessary to perform an initial calibration to reduce static errors and to have calibration parameters for adjusting the amount of light for each temperature.

The detection device according to this embodiment has a function for adjusting the amount of reflected light, which makes it possible to perform initial calibration and have calibration parameters for each temperature. As a result, it is possible to reduce errors in detecting objects due to environmental changes or environmental errors. In addition, since only one set of emission unit and detection unit, which are equivalent to the conventional light-emitting unit and light-receiving unit, is required, it can be provided at a low cost.

The detection device according to this embodiment will be described in detail with reference to the drawings. FIG. 2 is a diagram showing an example of the appearance of the detection device. The detection device 10 includes a housing 11. The housing 11 includes an object detection unit 12 and an equipment unit 13. Here, the device is described as including the object detection unit 12 and the equipment unit 13, but is not limited to this. For example, a part or all of the equipment unit 13 may be separated into one or more devices, and a detection system may be composed of multiple devices.

When the system is made up of multiple devices, the devices are not limited to being directly connected by cables or the like, but may be connected via one or more networks. The networks may be either wired or wireless.

The object detection unit 12 and the equipment unit 13 are each box-shaped and have an internal space. The object detection unit 12 and the equipment unit 13 are adjacent to each other and separated from each other by a partition wall 14. The object detection unit 12 has an internal space that serves as a detection space, and has a trapezoidal external shape. The equipment unit 13 has a rectangular parallelepiped external shape. Note that these shapes are merely examples and are not limited to these.

The object detection unit 12 includes a bottom wall 12a, a top wall 12b, and side walls 12c to 12e. The detection space is formed inside and surrounded by the bottom wall 12a, the top wall 12b, the side walls 12c to 12e, and the partition wall 14.

When the detection device 10 is placed on a placement surface, the bottom wall 12a is located at the bottom and contacts the placement surface. The top wall 12b is spaced upward from the bottom wall 12a and is provided opposite the bottom wall 12a. The side walls 12c to 12e are continuous with the bottom wall 12a and the top wall 12b and are provided to surround the periphery together with the partition wall 14. The side walls 12c to 12e are tapered from the bottom wall 12a toward the top wall 12b so as to narrow the detection space.

Each of the side walls 12c to 12e has an opening 15 at the lower portion that is continuous with the bottom wall 12a. The opening 15 is a long and narrow rectangle (slit-shaped) that extends along the edge of the bottom wall 12a. The opening 15 serves as an entry point for pests to enter the internal detection space from the outside.

The housing 11 is made of a non-metallic material and is black in color so that the reflectance of the infrared rays on the inner surface facing the detection space is a certain value or less, for example, 0.1% or less. Examples of materials include plastic, rubber, ceramic, etc., and plastics such as ABS resin (acrylonitrile butadiene styrene copolymer resin) can be used to make it lightweight and inexpensive to manufacture. Reflectance is the ratio of the luminous flux of reflected light to the luminous flux of incident light on a certain surface. The housing 11 may be made of a material with a reflectance of more than 0.1%, and the inner surface may be covered with a plate, sheet, film, paint, etc. with a reflectance of 0.1% or less. The color is preferably black to reduce reflectance, but dark brown or dark navy blue may also be used.

Figure 3 is a perspective view showing an example of the inside of a detection device, and Figure 4 is a plan view showing an example of the inside of a detection device. Figure 3 is a perspective view of the inside as seen from the top wall 12b side, and Figure 4 is a plan view of the inside as seen from the bottom wall 12a. In these figures, the short side direction of the bottom wall 12a is defined as the x-axis direction, the long side direction as the y-axis direction, and the upward direction where the top wall 12b is located as the z-axis direction. Figure 5 is a cross-sectional view of the housing 11 cut in the y-axis direction.

The object detection unit 12 has a raised portion 12f that protrudes in the z-axis direction from the inner surface of the bottom wall 12a. The raised portion 12f is made of the same material as the housing 11. The raised portion 12f may be made of a material different from that of the housing 11, and may be integrated with the bottom wall 12a. The raised portion 12f extends in a strip shape along three openings 15 provided along the edge of the bottom wall 12a, and is disposed near the openings 15. This is to suppress the radiation of infrared rays to the outside through the openings 15, and to absorb infrared rays that enter the inside from the outside through the openings 15.

When viewed from above, the raised portion 12f is formed in a U-shape, but is not limited to this shape. Like the housing 11, the raised portion 12f can be made of a material with an infrared reflectance of 0.1% or less. The raised portion 12f may also be made of a material with a reflectance of more than 0.1%, with the surface covered with a plate, sheet, film, paint, etc. with a reflectance of 0.1% or less. The color, like the housing 11, can be black, dark brown, dark navy blue, etc.

The distance between the opening 15 and the raised portion 12f and the protruding dimension of the raised portion 12f in the z-axis direction can be determined according to the shape and dimensions of the opening 15 and the desired suppression effect.

The equipment section 13 includes a control board 16 and a power supply 17. The control board 16 controls the entire detection device 10. The power supply 17 supplies the power required for the control board 16 to operate.

The control board 16 is supported on the bottom wall 12a by support legs 13a, and is disposed between the top wall 12b and bottom wall 12a of the housing 11. The control board 16 has a plate-shaped protrusion 13b that penetrates the partition wall 14 and extends into the detection space 12g in the y-axis direction. The protrusion 13b has an emission unit 18 disposed on its upper surface, and a detection unit 19 that detects infrared rays disposed on its lower surface.

The radiation unit 18 is composed of an infrared LED and a prism. The infrared LED emits infrared light with a wavelength range of approximately 700 to 2500 nm in the y-axis direction. The optical axis of the infrared LED may be parallel to the y-axis direction or may be inclined at a predetermined angle with respect to the y-axis direction.

The prism is positioned at a distance on the optical axis of the infrared LED, has a semi-cylindrical side, and emits the incident infrared radiation by diffusing it radially along the xy plane. This allows the infrared radiation to be emitted throughout the entire detection space 12g.

The detection unit 19 is, for example, an infrared sensor, and outputs a signal indicating the intensity of the received infrared light. As the infrared sensor, an infrared photodiode, an infrared phototransistor, or the like can be used. The detection unit 19 receives the reflected light of the infrared light that is emitted from the emission unit 18 and reflected back by the side walls 12c to 12e, etc., and converts it into a signal indicating the intensity of the received infrared light and outputs it.

Figure 6 shows an example of the hardware configuration of a detection device. The detection device 10 includes, as hardware, an emission unit 18, a detection unit 19, a power source 17, a control unit 20, a memory 21, an input/output unit 22, and a temperature measurement unit 23.

The control unit 20 is a CPU or the like, and executes a program stored in the memory 21 to control the entire detection device 10 and execute an initial calibration process and detection process, which will be described later. The memory 21 functions as a storage unit, and stores data such as tables and detection results, which will be described later, in addition to the program. The power source 17 is a storage battery or the like, and supplies power to the control unit 20. The input/output unit 22 is a communication I/F or the like, and controls communication with an external server or the like. The temperature measurement unit 23 is a temperature sensor or the like, and measures the temperature inside the housing 11 (detection space). Note that the control unit 20 is not limited to a unit that reads and executes a program from the memory 21 to perform control, etc., but may be composed of one or more circuits that perform control and each process exclusively.

Figure 7 is a block diagram showing an example of the functional configuration of the detection device. The detection device 10 includes an operation control unit 25, a dimension detection unit 26, a timer unit 27, an adjustment unit 28, and a temperature correction control unit 29 as functional units realized by the control unit 20.

The operation control unit 25 controls the overall operation of the detection device 10. The operation control unit 25 supplies power from the power source 17 to each component, and controls, for example, the turning on and off of the light source of the emission unit 18 and the detection operation of the detection unit 19. The operation control unit 25 determines the presence or absence of a pest based on the infrared light reception signal detected and output by the detection unit 19. When a pest invades the housing 11, the infrared light reflected by the pest is received and the output signal changes. The operation control unit 25 determines the presence or absence of a pest based on the presence or absence of this change.

The dimension detection unit 26 detects the dimensions of pests present inside the housing 11 based on the infrared light reception signal output from the detection unit 19. The dimension detection unit 26 identifies the size of the invading pest from the difference between the signal before the pest invades and the signal after the pest invades. The dimension detection unit 26 holds a table or the like to detect the dimensions corresponding to the signal difference, and can calculate the size of the pest using the table or the like. Note that the dimension detection unit 26 can execute the dimension detection process only when a pest is detected by the operation control unit 25.

The timer unit 27 measures time and outputs the measured time. Based on the measured time output by the timer unit 27, the operation control unit 25 instructs the temperature measurement unit 23 to measure the temperature inside the housing 11 at that time. The operation control unit 25 may also cause the temperature measurement unit 23 to constantly monitor the temperature, and when a designated temperature is reached, cause the temperature measurement unit 23 to output a signal and receive a notification that the designated temperature has been reached.

The adjustment unit 28 receives instructions from the operation control unit 25 and checks the calibration parameters (calibration values) that adjust the amount of infrared light received relative to the temperature as necessary.

The temperature correction control unit 29 determines whether the calibration value investigated by the adjustment unit 28 is valid or not based on the temperature output by the temperature measurement unit 23. The temperature correction control unit 29 determines that the calibration value investigated by the adjustment unit 28 when no pests are present in the housing 11 is valid, and stores the determined calibration value in the memory 21 in association with the temperature output from the temperature measurement unit 23. Furthermore, if a determined calibration value for the temperature output from the temperature measurement unit 23 is not stored in the memory 21, the temperature correction control unit 29 stores the calibration value investigated by the adjustment unit 28 in association with the temperature as a provisional calibration value in the memory 21. The provisional calibration value is a calibration value whose validity or invalidity cannot be determined at this point.

The temperature correction control unit 29 notifies the operation control unit 25 of the determined calibration value and a reference value (described later) that are stored in association with the temperature output by the temperature measurement unit 23. The operation control unit 25 sets the notified calibration value, controls the operation of the emission unit 18 or the detection unit 19, and executes the detection process. Depending on the result of the detection process, the temperature correction control unit 29 changes the provisional calibration value stored in the memory 21 to the determined calibration value.

Figure 8 shows an example of the configuration of the emission unit 18. The emission unit 18 includes a resistor 30, an infrared LED 31, and a switching element 32. The resistor 30 is a current limiting resistor that prevents an excessive current from flowing to the infrared LED 31. The infrared LED 31 serves as a light source and emits infrared rays when supplied with a current.

The switching element 32 functions as a switch, turning the switch ON/OFF and controlling whether or not current flows to the infrared LED 31. The switching element 32 is, for example, an n-MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). An n-MOSFET has three regions: a gate, a drain, and a source. When the voltage between the gate and source exceeds a threshold, current flows from the drain to the source, and the switch is in the ON state. When the voltage is smaller than the threshold, no current flows from the drain to the source, and the switch is in the OFF state. The infrared LED 31 is connected to the drain side, and is turned on when the switch is in the ON state and turned off when the switch is in the OFF state.

The radiator 18 modulates the infrared radiation it radiates to distinguish it from infrared radiation in nature. To achieve this modulation, a pulse-modulated voltage is applied to the gate of the n-MOSFET. For example, a pulse-modulated voltage with a frequency of 38 kHz is applied to the gate.

Figure 9 shows an example of the configuration of the detection unit 19. The detection unit 19 includes a PIN photodiode 33, an I-V conversion unit 34, an amplifier unit 35, a band-limiting filter 36, and a demodulation unit 37.

The PIN photodiode 33 has high-speed response characteristics and converts modulated infrared light into electric current. As long as it can convert infrared light into electric current, it is not limited to the PIN photodiode 33, and may be a PN photodiode, APD photodiode, or the like.

The I-V conversion unit 34 converts the current from the PIN photodiode 33 into a voltage. The amplification unit 35 converts the voltage into a signal and amplifies the signal by a set amplification factor. The band-limiting filter 36 is a filter that adjusts its center frequency to the modulation frequency, for example, 38 kHz, and passes only signals in that frequency band while attenuating other signals. The demodulation unit 37 converts the signal that has passed through the band-limiting filter 36 into an output signal.

Some of the infrared rays emitted from the emission unit 18 are absorbed within the housing 11, some leak outside the housing 11, and some are reflected and reach the detection unit 19. The detection unit 19 detects changes within the housing 11 from changes in the amount of reflected infrared light received. As a method for detecting this change, for example, a method can be adopted in which the reflected light in the initial state is kept constant, the value of the amount of light received at that time is set as a threshold, and if the value of the amount of light received exceeds the threshold, it is determined that an object such as a pest has entered the housing 11 and reflection from the object is occurring. Note that this method is merely an example and is not limited to this method. Below, a detailed explanation will be given assuming that this method is adopted.

To achieve this method, it is necessary to adjust the amount of received light, which varies from device to device, to a threshold value in the initial state. The adjustment of the amount of received light may be performed on the infrared emitting side or on the receiving side.

Examples of methods for adjusting the amount of light received on the irradiating side include adjusting the amount of current supplied to the infrared LED 31, and changing the modulation frequency of 38 kHz of the voltage (square wave) applied to the gate of the switching element 32. The latter method utilizes the fact that the amount of light changes according to the filter characteristics of the band-limiting filter 36 of the detection unit 19. Another example of a method for adjusting the amount of light received on the irradiating side is to adjust the pulse demodulation (pulse detection) sensitivity on the light receiving side by changing the pulse width of the 38 kHz voltage (square wave) applied to the gate of the switching element 32.

As a method for adjusting the amount of received light on the light receiving side, a method for adjusting the amplification factor set in the amplifier 35 of the detection unit 19 can be given as an example. These methods are merely examples, and the method for adjusting the amount of received light is not limited to these methods. In the following, we will explain the method of changing the modulation frequency, which can be easily realized by digital control.

Figure 10 is a flowchart showing an example of the initial calibration process. The initial calibration process is performed when the detection device 10 is turned on or initialized. This is because when the detection device 10 is turned on or initialized, it is highly likely that no pests have invaded the housing 11, and the state can be considered as being free of pests.

The initial calibration process starts at step 100, and at step 101, a certain period of time is awaited until the characteristics of the sensor or the like used as the temperature measurement unit 23 stabilize. Whether or not the certain period of time has elapsed is determined based on the time measured by the timer unit 27. This determination is made by the operation control unit 25.

After a certain period of time has elapsed, the process proceeds to step 102, where the operation control unit 25 instructs the temperature measurement unit 23 to measure the temperature, and the temperature measurement unit 23 receives the instruction and measures the temperature at that point in time. The temperature measured at this time becomes the temperature at the time of the initial calibration. For ease of explanation, let us assume that the measured temperature was 20°C.

After the temperature is measured, the calibration process is started. In the calibration process, in step 103, the adjustment unit 28 sets the modulation frequency to an initial value and initializes the frequency. The modulation frequency is 38 kHz, which is the frequency at which the maximum gain, i.e., the maximum amount of received light, is obtained, according to the characteristics of the band-limiting filter 36 of the detection unit 19. According to the characteristics of the band-limiting filter 36, whether the modulation frequency is higher or lower than 38 kHz, the amount of received light decreases from the maximum amount of received light. Therefore, after the calibration process, the amount of received light becomes a threshold value at two frequencies, 38 kHz or higher and lower than 38 kHz. For this reason, the initial value may be 38 kHz, or may be a frequency sufficiently higher or lower than 38 kHz. In this example, the initial value is set to, for example, 40 kHz, which is a sufficiently high frequency.

After the initial value is set, a frequency that is the threshold is searched for. In step 104, the emission unit 18 receives a voltage of the set frequency and emits infrared light according to that voltage. Since the set frequency is 40 kHz, which is sufficiently higher than 38 kHz, the amount of received light is sufficiently low and there is no reflected light.

In step 105, the detection unit 19 waits for a certain period of time to elapse, and detects the amount of light received as a cumulative value of the amount of light received during the certain period of time. When the detection is completed, in step 106, the emission of infrared rays by the emission unit 18 is stopped.

Here, the threshold value is set when the amount of received light is 0, and as the modulation frequency is lowered from 40 kHz to 38 kHz, the amount of received light will change from 0 at some frequency and become greater than 0. The frequency at which the amount of received light changes from 0 is set as the calibration value at a temperature of 20°C. In order to detect this change in the amount of received light, it is necessary to adjust the amount of infrared radiation so that a sufficiently large amount of received light can be detected at least when the frequency is set to the maximum amount of received light.

In step 107, the adjustment unit 28 determines whether the amount of received light, which is the detection result, exceeds a threshold value, thereby determining whether the set frequency is the frequency at which the amount of received light changes from 0. If not, the process proceeds to step 108, where the adjustment unit 28 changes the frequency, and the process returns to step 104. On the other hand, if the amount of received light exceeds a threshold value, the calibration process ends, and the process proceeds to step 109.

In step 109, the adjustment unit 28 stores the obtained calibration value in the memory 21, and ends the process in step 110. The calibration value is an initial calibration value, which is a value of frequency and temperature.

Figure 11 shows an example of a table that manages calibration values after the initial calibration process. The table shows a correspondence between each temperature and the frequency that should be set at that time. The frequencies include a determined frequency, a provisional frequency, and a reference frequency.

The determined frequency is a calibration value obtained by executing a calibration process in a state where no object has invaded the housing 11 or in a state where it can be determined that no object has invaded. The determined frequency also includes a provisional frequency obtained in the past when it can be determined that the provisional frequency was in a state where no pest has invaded or in a state where it can be determined that no pest has invaded.

The tentative frequency is a calibration value obtained when the calibration process is performed in a state where it cannot be determined that an object has not entered the housing 11. The reference frequency is a value that does not take into account the individual error of the device compared to the assumed value of the set frequency at each temperature that has been measured and stored in advance, and therefore is a value that takes into account the static individual error (offset value), which is the difference between the temperature and frequency value at the same temperature that has been measured in advance and stored from the temperature and frequency obtained at the time of initial calibration, and the same offset value is added to the assumed value of the frequency at each temperature in all temperature ranges. In addition, since the reference frequency does not take into account individual differences in temperature characteristics (dynamic individual error), it is a value that is treated only as a reference value.

The assumed value of the reference frequency may be stored in advance in a table, but is not limited to this. For example, it may be calculated from a formula that indicates temperature characteristics derived based on values previously measured at each temperature. Note that when calculating from a formula, the offset value obtained during initial calibration is also taken into account, but the reference frequency column does not need to be provided.

When the calibration process is performed when there is no object inside the housing 11, the frequency for the measured temperature can be determined and is entered in the determined frequency field. Therefore, if the frequency is determined to be 39.1 kHz when the measured temperature is 20°C in the initial calibration process, 39.1 kHz is entered in the determined frequency field corresponding to a temperature of 20°C, as shown in FIG. 11.

The temperature setting range can be set to, for example, 0 to 45°C, since cockroaches, a type of pest, are known to be active at temperatures between 20 and 32°C.

However, if the temperature characteristic of the expected value shows a nonlinear characteristic, and the nonlinear curve showing this characteristic varies depending on adjustment parameters other than frequency, there is a possibility that the expected value will deviate significantly within the temperature range simply by taking into account static individual errors (offset values). Adjustment parameters other than frequency include the pulse width, current amount, and amplification rate of the above-mentioned square wave. The expected value is used only for the purpose of making an assumption. On the other hand, if it takes time for the frequency to be adopted as the determined frequency, the detection results based on the expected value will be the basis. In that case, it is desirable for the deviation of the expected value to be as small as possible.

When adjusting the receiving sensitivity using the modulation frequency, the characteristic curve showing the relationship between the frequency and gain of the filter characteristics on the light receiving side is the curve showing the receiving sensitivity in the expected temperature range. However, if the emission intensity differs, the range of the characteristic curve used will differ, resulting in deviation from the expected value.

Figure 12 shows an example of how the shape of the characteristic curve differs when the gain change range in the characteristic curve on the light receiving side differs. In Figure 12, the curve shapes are illustrated by dotted lines and dashed lines to indicate that the shapes are different.

To eliminate such deviations, pre-processing is performed before the initial calibration process. Pre-processing is a process in which the amount of light emitted, i.e. the amount of infrared radiation irradiated, is adjusted using other adjustment methods so that the amount of light received is below a predetermined threshold value at the expected frequency value at the temperature at that time. An example of an other adjustment method is adjusting the amount of current.

Here, the assumed value is the assumed value of the frequency, which is one of the adjustment parameters, and the amount of current is adjusted as the other adjustment parameter, and the amount of current obtained by adjustment is determined as a fixed value. However, this is not limited to this, and the adjustment parameter may be a pulse width, amount of current, amplification factor, etc. other than the frequency, and the other adjustment parameters may be any parameter other than the one selected as the adjustment parameter, or may be two or more parameters other than the selected one.

Figure 13 is a flowchart showing the flow of pre-processing. When the power is turned on, operation starts from step 200. In step 201, a certain period of time is waited until the characteristics of the sensor used as the temperature measurement unit 23, etc., become stable.

After a certain period of time has elapsed, the process proceeds to step 202, where the operation control unit 25 instructs the temperature measurement unit 23 to measure the temperature, and the temperature measurement unit 23 receives the instruction and measures the temperature at that time.

After the temperature is measured, pre-processing begins. Pre-processing is performed by the pre-processing unit. In step 203, the pre-processing unit sets a reference frequency at that temperature. In step 204, the pre-processing unit instructs the emission unit 18 to receive a voltage of the set frequency and emit infrared rays according to that voltage.

In step 205, the preprocessing unit waits for a certain period of time to elapse, and instructs the detection unit 19 to detect the amount of received light as a cumulative value of the amount of light received in the certain period of time. When the detection is completed, in step 206, the emission unit 18 stops emitting infrared rays.

In step 207, the preprocessing unit determines whether the amount of received light, which is the detection result, exceeds a threshold value. If it does not exceed the threshold value, the process proceeds to step 208, where the preprocessing unit adjusts the amount of current to change the amount of emitted light, and returns to step 204. On the other hand, if it exceeds the threshold value, the current amount at that time is determined as a fixed value, and the preprocessing ends. Then, the process proceeds to calibration processing in step 209. The calibration processing has already been explained with reference to FIG. 10, so its explanation will be omitted here. After the calibration processing, the parameters are saved in step 210, and the processing ends in step 211.

By performing preprocessing in this way, even if the light emission amount adjustment precision is coarse, the light emission amount can be adjusted to approach a curve that indicates a certain degree of reception sensitivity, the deviation is not small, and the remaining deviation can be treated as a linear offset. In this case, the deviation can be significantly reduced by performing initialization calibration after preprocessing.

Figure 14 is a flowchart showing an example of a calibration process and a detection process that are executed at regular intervals. The calibration process needs to be executed not only when the detection device 10 is turned on or initialized, but also thereafter. This is because the temperature inside the housing 11 changes while the detection device 10 is operating. For this reason, it is necessary to check for changes in the state inside the housing 11 at regular intervals. The detection process may be executed at any time, but can also be executed in conjunction with the calibration process that is executed at regular intervals.

The timer unit 27 generates a trigger signal at regular intervals. Processing starts from step 300, and in step 301, the operation control unit 25 waits for the trigger signal to be generated, and instructs the temperature measurement unit 23 to measure the temperature upon receiving the trigger signal. In step 302, the temperature measurement unit 23 receives the instruction and measures the temperature inside the housing 11.

In step 303, the temperature correction control unit 29 determines whether the temperature measured by the temperature measurement unit 23 is a determined temperature. Whether the temperature is a determined temperature can be determined by whether a value is set in the determined frequency column, which is a valid frequency corresponding to that temperature, in the table that manages the calibration values.

If it is determined in step 303 that the temperature is a determined temperature, the temperature correction control unit 29 refers to the table in step 304 to obtain the determined frequency corresponding to that temperature, and notifies the operation control unit 25 of the obtained determined frequency. The operation control unit 25 sets the notified determined frequency and controls the frequency of the voltage input to the emission unit 18. Then, in step 305, the emission unit 18 receives a voltage of the set frequency and emits infrared rays according to that voltage.

In step 306, the detection unit 19 waits for a certain amount of time to pass, and detects the amount of light received as a cumulative value of the light received during that time. When the detection is completed, in step 307, the emission of infrared rays by the emission unit 18 is stopped. In step 308, the operation control unit 25 and the size detection unit 26 output the detection result based on the amount of light received, indicating whether or not a pest has invaded, and if so, the size of the pest, and so on, and store the detection result in memory 21, and the process ends in step 315.

If it is determined in step 303 that the temperature is not a determined temperature, the temperature correction control unit 29 determines in step 309 whether the temperature is a provisionally determined temperature. Whether the temperature is a provisionally determined temperature can be determined by whether a value is set in the provisional frequency column corresponding to the temperature in the table that manages the calibration values.

If it is determined in step 309 that the temperature is not a provisionally determined temperature, the process proceeds to step 310, where the adjustment unit 28 executes a calibration process. The calibration process is the process from step 103 to step 108 in FIG. 10. After the calibration process is executed, the process proceeds to step 311, where the temperature correction control unit 29 stores the calibration value in the memory 21 as a provisional parameter, and the process returns to step 309.

If it is determined in step 309 that the temperature is a provisionally determined temperature, the process proceeds to step 312, where the operation control unit 25 executes a frequency selection process. In the frequency selection process, a determined frequency or a reference frequency corresponding to a temperature close to the current measured temperature is selected.

If there is a decision frequency corresponding to a temperature within a certain temperature range relative to the current temperature, that decision frequency is selected. If there are multiple decision frequencies corresponding to temperatures within the certain temperature range, the decision frequency corresponding to the temperature closest to the current temperature is selected from the multiple decision frequencies. If there is no decision frequency corresponding to a temperature within the certain temperature range, a reference frequency corresponding to a temperature within the certain temperature range is selected, and if there are multiple reference frequencies, the reference frequency corresponding to the temperature closest to the current temperature is selected. The certain temperature range can be determined according to the frequency setting accuracy, the amount of change in the amount of light received, etc.

Figure 15 shows an example of a table that manages the calibration values referenced during frequency selection processing. For example, if the current temperature is 17°C, referring to the table reveals that neither the determined frequency nor the reference frequency has been input. In this case, if the fixed temperature range is set to ±1°C, the temperature range includes 16°C and 18°C, and since 39.1kHz has been input as the determined frequency for 18°C, 39.1kHz is selected. Note that although a reference frequency of 39.2kHz has been set for 16°C, the determined frequency takes priority since the reference frequency is a reference value that does not take into account individual errors in the temperature characteristics.

When the current temperature is 15°C, neither the decision frequency nor the reference frequency is set, so the frequencies of 14°C and 16°C are referenced. Decision frequencies are not input for 14°C and 16°C, but reference frequencies are input, so the reference frequency corresponding to the temperature closest to the current temperature is selected. In Figure 15, it is simply written as 14°C and 16°C, but one of the reference frequencies is selected taking into account the value after the decimal point. For example, taking into account the decimal point, if the current temperature is 15.1°C and the temperatures in the table are 14.2°C and 15.7°C within ±1°C, the reference frequency of 39.2kHz corresponding to the closest 15.7°C is selected.

In the table shown in FIG. 15, a frequency of 38.9 kHz is entered in the tentative frequency column as the calibration value obtained in the calibration process when the measured temperature is 24°C.

Referring again to FIG. 14, in the frequency selection process, a frequency is selected, and then the selected frequency is set for the emission unit 18. After the frequency selection process, in step 313, a detection process is executed. The detection process is the process from step 305 to step 307. In step 314, the operation control unit 25 and the dimension detection unit 26 output a provisional detection result, such as whether or not a pest has invaded, based on the amount of received light, and store the provisional detection result in memory 21, and the process ends in step 315.

After the initial calibration process, the calibration process is performed at regular time intervals. If the measured temperature is different at each time point, only the frequency determined by the initial calibration process is set as the determined frequency, and the rest are tentative frequencies. Since the detection process is not performed in the initial calibration process, at the temperature corresponding to the determined frequency, i.e., the determined temperature, it is unclear whether or not a pest has invaded the housing 11.

In the calibration process, which is performed at regular intervals, if the measured temperature is the determined temperature, the detection process is performed for the first time. If this detection process detects that no pests have invaded, it can be determined that the calibration processes performed up to that point also showed that no pests had invaded. For this reason, the provisional frequency obtained in the calibration processes performed up to that point can be considered the determined frequency.

On the other hand, if the intrusion of a pest is detected in a detection process executed when the measured temperature is the determined temperature, the detection results up to that point are provisional and cannot be used because it is not possible to identify the point in time of intrusion. Therefore, all provisional frequencies obtained up to that point cannot be used as determined frequencies. Therefore, all provisional frequencies obtained up to that point are invalid frequencies and can be deleted. In this case, the pest can be removed, initialization can be performed, and the initial calibration process can be executed again.

Figure 16 is a flow chart showing an example of a process for transitioning from a provisional frequency to a determined frequency. The process starts at step 400, and at step 401, the operation control unit 25 waits for a trigger signal to be generated from the timer unit 27, and instructs the temperature measurement unit 23 to measure the temperature upon receiving the trigger signal. At step 402, the temperature measurement unit 23 receives the instruction and measures the temperature inside the housing 11.

In step 403, the temperature correction control unit 29 determines whether the temperature measured by the temperature measurement unit 23 is a determined temperature. Whether the temperature is a determined temperature can be determined by whether a value is set in the determined frequency column corresponding to that temperature in the table that manages the calibration values.

If it is determined in step 403 that the temperature is a determined temperature, the temperature correction control unit 29 in step 404 refers to the table to obtain the determined frequency corresponding to that temperature, and notifies the operation control unit 25 of the obtained determined frequency. The operation control unit 25 sets the notified determined frequency and controls the frequency of the voltage input to the emission unit 18. Then, in step 405, the emission unit 18 receives a voltage of the set frequency and emits infrared rays according to that voltage. The detection unit 19 then receives the reflected infrared rays. In this manner, the detection process is executed. The detection process is the process from step 305 to step 307 in FIG. 14.

In step 406, the operation control unit 25 and the dimension detection unit 26 output the detection result, such as whether or not a pest has invaded, based on the amount of received light, and store the detection result in the memory 21. In step 407, the temperature correction control unit 29 refers to the detection result and checks whether or not a pest has invaded and is undetected, and if undetected, proceeds to step 408, and if detected, proceeds to step 409.

In step 409, the temperature correction control unit 29 transfers the provisional frequency entered in the table to the determined frequency column in the same table. Then, the process proceeds to step 411 and ends.

In step 409, the temperature correction control unit 29 deletes all tentative frequencies entered in the table. Then, the process proceeds to step 411 and ends.

If it is determined in step 403 that the temperature is not a determined temperature, the process proceeds to step 410, where a tentative determination process is executed. The tentative determination process is the process from step 309 to step 314 in FIG. 14. After the tentative determination process is completed, the process proceeds to step 411, where the process ends.

Figure 17 shows an example of a table that manages calibration values when transitioning from a provisional frequency to a determined frequency. As shown in Figure 11, initialization is performed at 20°C, and in the calibration process after a certain period of time has passed, the temperature is measured as 24°C as shown in Figure 15, and a provisional frequency of 38.9 kHz is obtained. In the calibration process after a further certain period of time has passed, the temperature is measured as 20°C, and the detection result is undetected.

Therefore, even in the calibration process at 24°C, it can be determined that no detection has occurred, so the provisional frequency of 38.9 kHz at 24°C shown in Figure 15 is transitioned to the determined frequency at 24°C, as shown in Figure 17.

When the provisional frequency is shifted to the determined frequency, the determined frequencies for 24°C and 26°C are entered, but the determined frequency for 25°C between them is left blank and has not been entered. Looking at the determined frequencies for 24°C and 26°C, both are 38.9kHz. In this way, if the determined frequency for a certain temperature is left blank and the determined frequencies for the temperatures above and below it are the same frequency, it can be determined that the determined frequency for the temperature sandwiched between the temperatures above and below is also the same frequency as the determined frequencies for the temperatures above and below it.

Therefore, it is determined that the determined frequency for 25°C is 38.9 kHz, the same as the determined frequencies for 24°C and 26°C, and 38.9 kHz is entered in the determined frequency column for 25°C, as shown in Figure 17.

In this way, by determining and inputting parameters such as the frequency for each temperature as needed, the table can be filled with the determined frequencies, the determined frequency for the measured temperature can be set, and the detection process can be executed. This reduces detection errors and allows the detection results to be output even if the temperature changes.

Figure 18 is a perspective view showing another example of the inside of the detection device 10. The detection device 10 includes an object detection unit 12 and an equipment unit 13, and further includes a trap unit 40 for capturing pests, and a switch unit 41 for attaching and detaching the trap unit 40. The object detection unit 12 and the equipment unit 13 have already been described, so only the trap unit 40 and the switch unit 41 will be described here.

The trap section 40 comprises an adhesive section 40a for capturing pests, an outer edge section 40b that surrounds the adhesive section 40a and is adjacent to the lower surface of the bottom wall 12a, and a protrusion section 40c that is provided on the outer edge section 40b and protrudes in the z-axis direction. The bottom wall 12a has a rectangular opening 50 of a predetermined size, for example, in the center. When the outer edge section 40b of the trap section 40 is adjacent to the lower surface of the bottom wall 12a, the adhesive section 40a is exposed within the opening 50. The adhesive section 40a is formed by, for example, attaching an adhesive sheet to the center of the plate-shaped trap section 40.

The switch unit 41 is provided on the bottom wall 12a and includes an insertion portion into which the protrusion 40c is inserted. The switch is turned ON by inserting the protrusion 40c into the insertion portion, and turned OFF by removing the protrusion 40c from the insertion portion. Note that this is just one example, and the present invention is not limited to this configuration.

The switch unit 41 can also function as a power switch. In this case, when the trap unit 40 is removed, the power is turned OFF, and when the trap unit 40 is attached, the power can be turned ON. For example, the protrusion 40c has a conductive portion, and the switch unit 41 has two contacts, and when the protrusion 40c is inserted into the insertion portion and the trap unit 40 is attached, the two contacts and the conductive portion are connected, and an electrical connection is established, and the power can be turned ON. In contrast, when the protrusion 40c is pulled out of the insertion portion and the trap unit 40 is removed, the electrical connection is released, and the power can be turned OFF. In this way, by having the switch unit 41 function as a power switch, when the trap unit 40 is attached, the power is turned ON, and it is possible to start from initialization.

When the trap unit 40 is replaced, due to variations in the shape of the trap, etc., the state of the detection space before and after replacement changes, and the amount of infrared light received also changes. For this reason, when the trap unit 40 is replaced, the power is turned OFF once, and then turned ON again, allowing the initialization process to be started over from the initial calibration process.

At this time, the result of the initial calibration process is output and can be notified to an external data server, etc., together with a flag indicating the result of the initial calibration process. By receiving this notification, the data server, etc. can record the date and time when the trap unit 40 was replaced.

So far, the present invention has been described with reference to the above-mentioned embodiments of a detection device, detection system, and detection method. However, the present invention is not limited to the above-mentioned embodiments, and can be modified within the scope of what a person skilled in the art can conceive, including other embodiments, additions, modifications, deletions, etc. Furthermore, any embodiment is within the scope of the present invention as long as it achieves the functions and effects of the present invention.

Therefore, it is possible to provide a program for implementing each function of the control unit, a recording medium on which the program is recorded, a server device that stores the program and provides it upon receiving a download request, etc. The detection system may also be configured to include the data server, etc., described above.

10...detection device 11...housing 12...object detection section 12a...bottom wall 12b...upper wall 12c-12e...side wall 12f...raised portion 12g...detection space 13...equipment section 13a...support leg 13b...protrusion 14...partition 15...opening 16...control board 17...power supply 18...radiation section 19...detection section 20...control section 21...memory 22...input/output section 23...temperature measurement section 25...operation control section 26...dimension detection section 27...timekeeping section 28...adjustment section 29...temperature correction control section 30...resistor 31...infrared LED
32... Switching element 33... PIN photodiode 34... I-V conversion section 35... Amplification section 36... Band-limiting filter 37... Demodulation section 40... Trap section 40a... Adhesive section 40b... Outer edge section 40c... Protrusion 41... Switch section 50... Opening

Patent No. 2727293 JP 2017-192321 A

Claims (16)

An apparatus for detecting an object, the object being a pest;
A housing whose inner surface has a reflectance equal to or lower than a certain level;
A radiation means for radiating infrared rays into the housing;
A detection means for detecting infrared rays;
an adjustment means for adjusting an intensity of reflection of infrared light in response to a detection result of the detection means ;
A trap means is replaceably attached to the housing for trapping the pests;
a switch means for cutting off a power supply when the trap means is removed from the housing and for turning on a power supply when the trap means is attached to the housing;
Including ,
the adjustment means executes an initialization process each time the trap means is replaced, the initialization process being for adjusting the reflection intensity of the infrared ray to a predetermined value in a state in which the object is not present within the housing.
Detection device. The radiation means receives a square wave input and radiates modulated infrared light,
The detection device according to claim 1 , wherein the adjustment means adjusts the frequency of the rectangular wave so that the reflection intensity of the infrared ray becomes a predetermined value when the object is not present within the housing. The radiation means receives a square wave input and radiates modulated infrared light,
2. The detection device according to claim 1, wherein the adjustment means adjusts a pulse width of the rectangular wave so that a reflection intensity of the infrared ray becomes a predetermined value when the object is not present within the housing. The radiation means radiates infrared rays in accordance with an amount of input current,
The detection device according to claim 1 , wherein the adjustment means adjusts the amount of current so that the reflection intensity of the infrared ray becomes a predetermined value when the object is not present within the housing. The radiation means receives a square wave input and radiates modulated infrared light,
the detection means includes an amplification means for amplifying the amount of infrared light detected,
2. The detection device according to claim 1, wherein the adjustment means adjusts the amplification factor of the amplification means so that the reflection intensity of the infrared ray becomes a predetermined value when the object is not present within the housing. The detection device according to any one of claims 2 to 5, wherein the detection device detects the object depending on whether the reflection intensity exceeds the predetermined value. A temperature measuring means for measuring a temperature inside the housing;
The detection device according to any one of claims 1 to 6, further comprising a temperature correction control means for determining whether or not a value adjusted by said adjustment means is valid at the temperature measured by said temperature measurement means. The detection device according to claim 7, wherein the temperature correction control means determines that the value adjusted by the adjustment means is valid when the object is not present in the housing, and stores the determined value in the storage means in association with the temperature measured by the temperature measurement means. The detection device according to claim 8, wherein, when the determined value for the temperature measured by the temperature measuring means is not stored in the storage means, the temperature correction control means stores the value adjusted by the adjustment means as a provisional value in association with the temperature in the storage means. The detection device according to any one of claims 7 to 9, wherein the temperature correction control means sets values measured in advance at each temperature as assumed values at each temperature, stores them in the storage means in association with each temperature, and sets values obtained by adding individual errors to the assumed values as reference values. The detection device according to any one of claims 7 to 9, wherein the temperature correction control means calculates an expected value from a formula derived based on values previously measured at each temperature, and sets a value obtained by adding an individual error to the expected value as a reference value. the adjustment parameters at each temperature, which are the assumed values, are selected from a frequency of a square wave input for emitting the infrared ray, a pulse width of the square wave, and an amplification factor of an amplifier that amplifies the detected amount of the infrared ray;
12. The detection apparatus according to claim 10, further comprising a pre-processing means for determining fixed values of adjustment parameters other than the selected adjustment parameter when the fixed values are to be set to the adjustment parameters. The detection device according to any one of claims 10 to 12, further comprising an operation control means for controlling the emission means or the detection means using a determined value or a reference value stored in association with a temperature closest to the temperature measured by the temperature measurement means, when a determined value that is determined to be valid for the temperature measured by the temperature measurement means is not stored in the storage means. The detection device according to claim 9, wherein the temperature correction control means changes each of the provisional values associated with each of the temperatures stored up to that point to each of the determined values, corresponding to the temperatures measured by the temperature measurement means, in the storage means when the object is not detected in the object detection process, and stores the determined values in the storage means in association with the temperatures. 1. A detection system for detecting an object, the object being a pest;
A housing whose inner surface has a reflectance equal to or lower than a certain level;
A radiation means for radiating infrared rays into the housing;
A detection means for detecting infrared rays;
an adjustment means for adjusting an intensity of reflection of infrared light in response to a detection result of the detection means ;
A trap means is replaceably attached to the housing for trapping the pests;
a switch means for cutting off a power supply when the trap means is removed from the housing and for turning on a power supply when the trap means is attached to the housing;
Including ,
the adjustment means executes an initialization process each time the trap means is replaced, the initialization process being for adjusting the reflection intensity of the infrared ray to a predetermined value in a state in which the object is not present within the housing.
Detection system. A detection method performed by a detection device that detects an object, the object being a pest,
emitting infrared rays from a radiation means into a housing whose inner surface has a reflectance equal to or lower than a certain level;
detecting infrared light by a detection means;
detecting the object based on a detection result of the detection means ;
a step of cutting off a power supply when a trap for capturing the pest, which is replaceably attached to the housing, is removed, and turning on a power supply when the trap is attached to the housing;
Including,
a step of adjusting the reflection intensity of the infrared rays according to the detection result of the detection means, and performing an initialization process each time the trap is replaced, in which the reflection intensity of the infrared rays is adjusted to a predetermined value in a state in which the object is not present within the housing.
The detection method further comprises: