Sensor device and vending machine equipped with same

Abstract

To provide a sensor device capable of responding to complicated or irregular operations and capable of detecting the presence or absence of a detection object with high detection accuracy, and a vending machine provided with the sensor device.SOLUTION: A device includes a Doppler sensor, a reflection signal extraction unit 110, a reflection signal storage unit 120, a distance calculation unit 130, an array storage unit 140, an analysis unit 150, and a determination unit 160. The distance calculation unit 130 calculates a distance between an installation V and a detection object X based on a plurality of reflection signals stored in the reflection signal storage unit 110. The array storage unit 140 stores a plurality of converted distance data arranged in the order of reception of the reflection signals. The analysis unit 150 analyzes the approach, stop, and disengagement of the detection object X with respect to the installation V based on a correlation of data values showing the increasing and decreasing trends of the plurality of distance data values or the slope of the data values. The determination unit 160 determines the presence or absence of the detection object X based on an analysis result of the analysis unit 150.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a sensor device that detects a detection target such as a person, and a vending machine equipped with the same. [Background technology]

[0002] Sensor devices that detect the presence or absence of a person without contact have been known for some time. For example, a sensor device detects whether a person is standing in front of a vending machine, and when a person approaches the vending machine and stands still, the LED lighting, price display, switch buttons, etc. of the vending machine are brightened, and when the person moves away from the vending machine, the LED lighting, price display, switch buttons, etc. are dimmed, thereby controlling the brightness of the lighting, etc., to achieve energy saving in the vending machine.

[0003] Such sensors for detecting the presence or absence of a person in a non-contact manner include those that detect the target by transmitting and receiving light waves such as infrared rays, or radio waves such as ultrasound and microwaves. For example, the following patent document shows a Doppler sensor that irradiates the target with radio waves such as microwaves and uses the Doppler effect of the reflected signal. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5077803 [Patent Document 2] JP 2004-125399 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in Patent Document 1, the approach or departure of a person is judged by comparing the voltage value with a specified threshold value, and therefore the approach or departure is judged based on the voltage value, and therefore the problem is that it is bound to a specific threshold value.In addition, in Patent Document 1, the approach or departure of a person is judged by comparing an analog waveform with a gradual drop in the detected voltage value with the voltage value of the output signal and the threshold value, so it cannot handle complex or irregular human movements such as taking out a wallet from a vending machine or bending down to take out a purchased drink, and also, when a person is completely still, if the voltage value is below the threshold value, the sensor will detect that the person is absent, and the detection accuracy of the sensor is insufficient.

[0006] Furthermore, in Patent Document 2, the approach or departure of the detected object is determined based on the slope between the maximum or minimum extreme values ​​of the amplitude of the reflected signal of the Doppler sensor. As a result, like Patent Document 1, Patent Document 2 also has the problem of being unable to respond to complex or irregular human movements, resulting in insufficient detection accuracy of the sensor.

[0007] The present invention has been proposed to solve the problems of the prior art as described above. An object of the present invention is to provide a sensor device capable of dealing with complex or irregular movements of a detection target and detecting the presence or absence of the detection target with high detection accuracy, and a vending machine equipped with the same. [Means for solving the problem]

[0008] In order to achieve the above object, a sensor device according to the present invention is characterized by having the following configuration. (1) A Doppler sensor having a transmitter that transmits a radio signal to the outside of the installation object, and a receiver that receives a reflected signal of the radio signal from an object to be detected. (2) a reflected signal extracting unit that extracts the reflected signal received by the receiving unit at a predetermined interval; (3) a reflected signal storage unit for storing a plurality of the reflected signals extracted at a predetermined interval by the reflected signal extraction unit; (4) A distance calculation unit that calculates the distance between the installation and the detection target at the time each reflected signal is extracted based on the multiple reflected signals stored in the reflected signal storage unit. (5) an array storage unit that arrays and stores the plurality of distance data converted by the distance calculation unit in the order in which the reflected signals are received; (6) An analysis unit that compares the multiple distance data values ​​stored in the array storage unit and analyzes the approach, stopping, and departure of the detected object from the installed object based on a slope of data values ​​that indicate an increase / decrease tendency of the multiple distance data values. (7) A determination unit that determines the presence or absence of a detection target relative to the installation object based on the analysis results of the analysis unit.

[0009] In the present invention, the following configurations can be adopted. (1) When comparing the multiple distance data values, the analysis unit determines the correlation between the multiple distance data values, and analyzes the approach, stopping, and departure of the detected object from the installed object based on this correlation and the slope of the data values ​​that indicate the increase / decrease tendency of the multiple distance data values. (2) The reflected signal extraction unit includes an outlier removal unit that compares the reflected signal with a predetermined threshold, determines that the reflected signal that meets the predetermined conditions is an outlier signal, and removes it from the reflected signals to be extracted. (3) The determination unit continues to hold the presence determination as the approach or stationary motion of the detection target during the period from when the presence determination is made to when the absence determination is made.

[0010] A vending machine equipped with a sensor device having the above-described configuration, and a vending machine equipped with an illuminance sensor in addition to the sensor device having the above-described configuration are also aspects of the present invention. Effect of the Invention

[0011] According to the present invention, it is possible to respond to complex or irregular movements of a detection target, and it is possible to detect the presence or absence of a detection target with high detection accuracy. [Brief description of the drawings]

[0012] [Figure 1] 1A to 1C are diagrams showing a usage mode of the first embodiment, in which (a) is an image diagram showing an approaching motion, (b) is a stationary motion, and (c) is a diagram showing a moving away motion. [Diagram 2] 1 is a block diagram showing an overall configuration of a first embodiment; [Diagram 3] FIG. 2 is a block diagram showing a configuration of a data processing unit in the first embodiment. [Figure 4] 1 is a flowchart showing five-stage threshold division in the first embodiment. [Diagram 5] 4 is a graph showing a presence / absence determination process in the first embodiment. [Figure 6] 5 is a flowchart showing an approach / leave detection process (processing using a correlation coefficient) according to the first embodiment. [Figure 7] 13 is a flowchart showing an approach / leave detection process (processing without using a correlation coefficient) that is a modification of the first embodiment. [Figure 8] 4 is a flowchart showing an approach / leave control process in the first embodiment. [Figure 9] FIG. 11 is a block diagram showing the overall configuration of a second embodiment. [Figure 10] FIG. 11 is a block diagram showing a configuration of a data processing unit in a second embodiment. [Figure 11] 13A to 13C are diagrams illustrating a method for calculating the amount of fluctuation in illuminance data according to the second embodiment. [Figure 12] 13 is a graph showing a presence / absence determination process according to the second embodiment. [Figure 13] 13 is a graph showing a presence / absence determination process in a modified example of the second embodiment. [Figure 14] 10 is a flowchart showing an approach detection process according to a second embodiment. [Figure 15] 13 is a flowchart showing a separation detection process according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] [1. First embodiment] [1-1. Configuration of the first embodiment] As shown in FIG. 1, the present invention detects the presence or absence of a detection target X in the vicinity of a vending machine V (hereinafter referred to as installation V) when the detection target X approaches, stops, and moves away from the installation V. As shown in FIG. 1(a), when the detection target X detects a movement approaching the installation V, the sensor switches from "absent" to "present." As shown in FIG. 1(b), when the detection target X detects a movement of stopping in front of the installation V, the sensor maintains the "present" state. As shown in FIG. 1(c), when the detection target X detects a movement of moving away from the installation V, the sensor switches from "present" to "absent."

[0014] A first embodiment of the present invention will be described in detail below with reference to Fig. 2. As shown in Fig. 2, the sensor device of this embodiment is installed on an object V, which is a vending machine, and has a Doppler sensor 100 and a data processing unit 105. As shown in Fig. 3, the data processing unit 105 includes a reflected signal extraction unit 110, a reflected signal storage unit 120, a distance calculation unit 130, an array storage unit 140, an analysis unit 150, and a determination unit 160.

[0015] The Doppler sensor 100 detects an object X within a predetermined detection range. The Doppler sensor 100 includes a transmitter 101 that transmits a radio signal to the outside of an installed object V, and a receiver 102 that receives a reflected signal of the radio signal from the object X. The transmitter 101 includes a dielectric resonator for generating a radio signal. The transmitter 101 transmits the radio signal generated by the dielectric resonator to the outside of the installed object V. The receiver 102 receives the reflected signal that the transmitter 101 transmitted to the outside and that was reflected back by all or part of the object X, and transmits the received signal to a reflected signal extraction unit 110.

[0016] The reflected signal extracting unit 110 includes a non-linear element such as a diode or a transistor, and extracts the reflected signal received by the receiving unit 102 at predetermined intervals.

[0017] The reflected signal extraction unit 110 includes an outlier removal unit 111 that compares the reflected signal with a preset threshold, determines that the reflected signal that satisfies a preset condition is an outlier signal, and removes it from the reflected signal to be extracted. Specifically, the following cases (1) to (3) are defined as outliers. (1) When the approach threshold E, departure threshold E, or absence information is acquired from the threshold information in Table 1, a reflected signal that is shorter than a certain period of time (e.g., 300 msec) is regarded as an outlier. (2) When the approach threshold E, the departure threshold E, or the absence information is acquired, a reflected signal that has never been removed as an outlier from the approach threshold E, the departure threshold E, or the absence information before is regarded as an outlier. (3) If the approach threshold A or the departure threshold A is acquired and then a threshold other than the approach threshold A or the departure threshold A reacts, then if a reflected signal corresponding to the departure threshold A is detected again, it is considered an outlier.

[0018] Note that this removal of outliers may be performed by the reflected signal extraction unit 110 as described above, or in the analysis unit 150, if the reflected signal that is the source of the distance data in the array satisfies the conditions (1) to (3) above, the distance data can be excluded as an outlier.

[0019] The reflected signal storage unit 120 stores a plurality of reflected signals extracted by the reflected signal extraction unit 110 at predetermined intervals.

[0020] The distance calculation unit 130 calculates the distance between the installation object V and the detection target X at the time of extracting each reflected signal based on the multiple reflected signals stored in the reflected signal storage unit 110. In this embodiment, For example, as shown in Table 1 below, the distance calculation unit 130 calculates the distance between the installation object V and the detection target X at the time of extracting each reflected signal according to five threshold levels. Specifically, the threshold information is divided into three categories: approach threshold, departure threshold, and absence information, and the approach threshold and departure threshold are each divided into five categories: A, B, C, D, and E. According to each threshold information classified in this way, the distance calculation unit 130 performs distance conversion to 500 mm, 1000 mm, 1500 mm, 2000 mm, 5000 mm, and 6000 mm.

[0021] That is, the threshold information in Table 1 is the output value of Doppler sensor 100 received by receiving unit 102 and extracted by reflected signal extraction unit 110, and the output value is given as an electrical signal of voltage, frequency, phase difference, etc. depending on the configuration and type of the Doppler sensor. In this embodiment, the output value of the electrical signal obtained according to the distance between installed object V and detection target X is not used as it is to determine "presence" or "absence", but the output value is converted to distance in distance calculation unit 130.

[0022] [Table 1]

[0023] The array storage unit 140 arrays and stores the five-level distance data converted by the distance calculation unit 130 in the order in which the reflected signals are received. That is, in this embodiment, the reflected signals obtained at a predetermined time interval are converted into five-level distance data, and the analysis unit 150 analyzes the change over time in the distance between the installation object V and the detection target X detected by the Doppler sensor.

[0024] The analysis unit 150 compares the multiple distance data values ​​stored in the array storage unit 140, and analyzes the approach, stop, and departure of the detection target X from the installation V based on the slope of the data values ​​indicating the increase / decrease tendency of the multiple distance data values. When comparing the multiple distance data values, the analysis unit 150 determines the correlation between the multiple distance data values, and analyzes the approach, stop, and departure of the detection target X from the installation V based on this correlation and the slope of the data values ​​indicating the increase / decrease tendency of the multiple distance data values.

[0025] Based on the analysis result of the analysis unit 150, the determination unit 160 determines the presence or absence of the detection target X relative to the installed object V. From the time of the presence determination to the time of the absence determination, the determination unit 160 continues to hold the presence determination as an approaching or stationary motion of the detection target X.

[0026] [1-2. Operation of the First Embodiment] A radio signal transmitted from a transmitter 101 of a Doppler sensor 100 is reflected by a detection target X, and a receiver 102 receives the reflected signal. The reflected signal is extracted at a predetermined interval by a reflected signal extractor 110 and stored in a reflected signal storage unit 120. The reflected signals stored in the reflected signal storage unit 120 are classified into five threshold levels by a distance calculator 130.

[0027] FIG. 4 is a flow chart for explaining the five-level threshold division for the reflected signal of the first embodiment having the above-mentioned configuration. As shown in FIG. 4, whether or not the threshold A reacts is confirmed (step S01). If the threshold A reacts (YES in step S01), it is determined to be the threshold A. If the threshold A does not react (NO in step S01), whether or not the threshold B reacts is confirmed (step S02). If the threshold B reacts (YES in step S02), it is determined to be the threshold B. If the threshold B does not react (NO in step S02), whether or not the threshold C reacts is confirmed (step S03). If the threshold C reacts (YES in step S03), it is determined to be the threshold C. If the threshold C does not react (NO in step S03), whether or not the threshold D reacts is confirmed (step S04). If the threshold D reacts (YES in step S04), it is determined to be the threshold D. If the threshold D does not react (NO in step S04), whether or not the threshold E reacts is confirmed (step S05). If the threshold value E reacts (YES in step S05), it is determined to be the threshold value E.

[0028] If the threshold value E does not react (NO in step S05), the absence threshold value N is transmitted, and the process returns to the start and steps S01 to S05 are performed again.

[0029] According to each threshold information classified by the distance calculation unit 130, the reflected signal is converted into distance data of 500 mm, 1000 mm, 1500 mm, 2000 mm, 5000 mm, and 6000 mm.

[0030] 5 to 7, a process of detecting the approach, stop, and departure of the detection target X and judging the presence or absence of the detection target X relative to the installation object V will be described.

[0031] The upper part of FIG. 5 is a graph showing the result of performing a presence / absence judgment process for the detection target X on the distance data stored in the array storage unit 140 after arranging a plurality of distance data converted by the distance calculation unit 130 in the order of reception of the reflected signals. The vertical axis of the graph in the upper part of FIG. 5 indicates the output distance (mm) of the Doppler sensor 100, and the threshold values ​​(A to E) are shown as the output distance values ​​on the vertical axis. The horizontal axis indicates the elapsed time (sec), and the distance data extracted at a predetermined interval by the reflected signal extraction unit 110 is displayed as a bar graph for each extraction time. In FIG. 5, the distance data is divided into three categories: approach, stationary, and departure, depending on the tendency of increase / decrease in the distance data value and the elapsed time. The graph in the lower part of FIG. 5 shows the state of the judgment of the detection target X being "presence" or "absence" obtained based on the tendency of increase / decrease in the distance data value in the upper part, with the vertical axis indicating the judgment state (0 is absent, 1 is present) and the horizontal axis indicating the elapsed time (sec).

[0032] Fig. 6 is a flowchart showing the approach / leave detection process performed by the analysis unit 150. As shown in Fig. 6, it is checked whether or not the thresholds A to D react (step S11). If the thresholds A to D react (YES in step S11), it is checked whether or not the threshold A reacts (step S12). If the threshold A reacts (YES in step S12), it is immediately determined that the object is present. Returning to the start, it is checked again whether or not the thresholds A to D react (step S11).

[0033] If the thresholds B to D react (NO in step S12), it is checked whether the slope of the data values ​​indicating the increase / decrease tendency of the multiple distance data values ​​is equal to or greater than a certain level (step S21). The slope of the multiple distance data values ​​is determined by comparing the difference between two adjacent distance data values ​​and judging whether the slope of the data values ​​is equal to or greater than a certain level depending on the magnitude of the difference. In this case, an average value of the differences between three or more data values ​​may be calculated and judged whether it is equal to or greater than a certain level. Also, the increase / decrease in the slope is judged by whether the difference is positive or negative. If the slope of the data values ​​indicating the increase / decrease tendency of the multiple distance data values ​​judged as above is not equal to or greater than a certain level (NO in step S21), it is returned to the start and it is checked again whether the thresholds A to D react (step S11).

[0034] If the slope of the data values ​​showing the increase / decrease tendency of the multiple distance data values ​​is equal to or greater than a certain level (YES in step S21), it is checked whether the correlation between the multiple distance data values ​​is equal to or greater than a certain level (step S22). This correlation check is performed, for example, based on the following conditions: (1) Are the extraction times of the multiple distance data values ​​to be compared within a certain range? (2) The multiple distance data values ​​show a gradual decrease or increase trend, and there are no distance data values ​​among the multiple distance data values ​​that deviate from the gradual decrease or increase trend.

[0035] If the correlation between the multiple distance data values ​​is greater than or equal to a certain level (YES in step S22), check whether the slope is negative (step S23). If the slope is negative (YES in step S22), it is determined that the vehicle is approaching. If the correlation between the multiple distance data values ​​is not greater than or equal to a certain level (NO in step S22), return to the start and check again whether the thresholds A to D react (step S11). If the slope is not negative (NO in step S23), it is determined that the vehicle is separating.

[0036] Fig. 8 is a flowchart showing the approach / leave control process by the determination unit 160. As shown in Fig. 8, it is confirmed whether or not the detection target X is approaching based on the analysis result of the analysis unit 150 (step S31). If the detection target X is approaching (YES in step S31), it is determined that the detection target X is present (step S32). If the detection target X is not approaching (NO in step S31), it returns to the start and it is confirmed whether or not the detection target X is approaching (step S31).

[0037] After the presence determination, it is checked whether or not the detection target X has left based on the analysis result of the analysis unit 150 (step S33). If the detection target X has left (YES in step S33), it is determined that the detection target X is not present, and the process ends. If the detection target X has not left (NO in step S33), it is checked again whether or not the detection target X has left based on the analysis result of the analysis unit 150 (step S34).

[0038] The determination unit 160 continues to hold the presence determination as the approach or stationary motion of the detection target X from the time of the presence determination to the time of the absence determination.

[0039] [1-3. Effects of the first embodiment] (1) According to the sensor device of the present embodiment, by using distance data converted from a reflected signal from a Doppler sensor to analyze its increasing / decreasing tendency, it is possible to eliminate the influence of disturbances in the reflected signal and erroneous recognition caused by complex or irregular movements of the detection target X, and it is possible to detect the presence or absence of the detection target X with high detection accuracy, compared to conventional techniques that make judgments based on the state of the reflected signal at a specific point in time.

[0040] (2) According to the sensor device of this embodiment, the output value of the reflected signal obtained at a specified time interval is converted into distance data, and the approach, stationary, and moving away are determined based on multiple threshold values. Therefore, a sensor device with high detection accuracy can be provided with a relatively simple configuration that uses less data and processing.

[0041] (3) According to the sensor device of the present embodiment, even when a reflected signal cannot be accurately extracted due to a change in the speed of the detection target X or the like due to the nature of the Doppler sensor, the outlier removal unit determines that a reflected signal that meets preset conditions is an outlier signal and removes it from the reflected signal to be extracted. This makes it possible to detect the presence or absence of the detection target X with higher detection accuracy.

[0042] (4) According to the sensor device of this embodiment, the presence determination is continued as the detection target X approaches or moves to a standstill from the time of the presence determination to the time of the absence determination. Therefore, compared to a sensor that determines an absence when a certain amount of time has elapsed since the presence determination, when the detection target X is within a specified detection range, it is possible to more accurately detect the presence or absence of the detection target X without being bound by a specific time.

[0043] (5) According to the sensor device of this embodiment, when comparing multiple distance data values, the correlation between the multiple distance data values ​​is determined, and the approach, stop, and departure of the detection target X from the installation object V are analyzed based on this correlation and the slope of the data values ​​that indicate the increase and decrease trends of the multiple distance data values. Therefore, even when the reflected signal cannot be accurately extracted due to the speed change of the detection target X, which is unique to the Doppler sensor, it is possible to detect the presence or absence of the detection target X with higher detection accuracy by taking into account the extraction time and the gradual decrease and increase trends of the multiple distance data values.

[0044] [2. Second embodiment] [2-1. Configuration of the second embodiment] A second embodiment of the present invention will be described below. As shown in Fig. 9, the configuration of the second embodiment is such that an illuminance sensor 200 is further provided in addition to the Doppler sensor 100 of the first embodiment. The illuminance sensor 200 of the second embodiment has the following configuration. Note that a description of the parts common to the first embodiment will be omitted. (1) An illuminance sensor installed in the installation. (2) an illuminance data storage unit that sequentially stores, as one frame, the illuminance data output from the illuminance sensor at predetermined time intervals; (3) A matching data setting unit that sets the illuminance data of the latest frame among the illuminance data of the plurality of frames stored in sequence in the illuminance data storage unit as matching data. (4) A data update unit that updates the matching data set in the illuminance data storage unit to the illuminance data of the latest frame when illuminance data of a new frame is input to the illuminance data storage unit from the illuminance sensor. (5) A calculation unit that compares the matching data with illuminance data of multiple past frames stored in the illuminance data storage unit prior to the matching data, and calculates the sum of the differences between the matching data and the past illuminance data of the frame in which the error between the two is minimal. (6) A presence status determination unit that compares the sum calculated by the calculation unit with a preset reference value, and determines whether the object to be detected is present or absent if the sum calculated by the calculation unit exceeds the reference value. (7) An unoccupied state determination unit that detects that a value equivalent to the illuminance data value of a frame in a state before the occupancy state determination unit determines that the occupancy state has been determined, and determines that the transition from the occupancy state to the unoccupied state has been completed.

[0045] A second embodiment of the present invention will be described in detail below. In this embodiment, an installation object V is installed in an environment with a certain amount of light due to the surrounding environment, such as natural light, street lighting, and lighting from other surrounding buildings. Therefore, when a detection target X, such as a person, approaches the installation object V, the light reaching the installation object V is blocked by the detection target, and the amount of light reaching the illuminance sensor provided on the installation object V decreases. The illuminance sensor of this embodiment detects this change in the amount of light in the surrounding environment to determine whether the detection target X is present or absent.

[0046] 9, the sensor device of this embodiment is installed on an object V in the above-mentioned environment, and includes an illuminance sensor 200 and a data processing unit 205. As shown in FIG 10, the data processing unit 205 includes an illuminance data storage unit 210, a matching data setting unit 220, a data updating unit 230, a calculation unit 240, a presence status determination unit 250, and an absence status determination unit 260.

[0047] The illuminance sensor 200 converts the amount of light input from the environment around the installation object V into an electrical signal, and detects it as illuminance data. The illuminance sensor 200 transmits the input illuminance data to the illuminance data storage unit 210.

[0048] The illuminance data storage unit 210 sequentially stores the illuminance data output from the illuminance sensor 200 at preset specific time intervals. The "predetermined time intervals" can be set arbitrarily, but if it is set to every 10 msec, for example, the illuminance data storage unit 210 A / D converts the illuminance data received from the illuminance sensor 200 at every 10 msec, and sequentially stores the illuminance data acquired as log data. In the graph of Fig. 11(b), the waveforms at short intervals in the upper row are the illuminance data acquired at every 10 msec.

[0049] The matching data setting unit 220 sets the illuminance data of the latest frame of the illuminance data stored every 0.5 seconds as one frame by grouping the illuminance data in the upper row of Fig. 11(b) stored sequentially in the illuminance data storage unit 210 for 0.5 seconds as one frame, as the matching data. The graph in Fig. 11(a) shows the matching data for 0.5 seconds set by the matching data setting unit 220.

[0050] When new frame illuminance data is input to the illuminance data storage unit 210 from the illuminance sensor 200 every 0.5 seconds, the data update unit 230 updates the matching data set in the illuminance data storage unit 210 to the illuminance data of the latest frame.

[0051] The calculation unit 240 compares the matching data with the illuminance data of a plurality of past frames stored in the illuminance data storage unit 210 before the matching data, and calculates the sum of the differences between the past illuminance data of the frame in which the error between the two is the smallest and the matching data. That is, the calculation unit 240 compares the latest 0.5 sec of matching data shown in FIG. 11(a) with the illuminance data of a plurality of past frames shown in FIG. 11(b) stored in the illuminance data storage unit 210 before the matching data (also called "past data"), and matches the two. Among the plurality of frames belonging to the past data, the frame whose waveform pattern is most similar to the matching data is extracted, in other words, the past frame whose error is the smallest when comparing the matching data with the illuminance data of the past frame. For example, among the plurality of frames shown in FIG. 11(b), the thick line part shown in the center is the frame in which matching is achieved. FIG. 11(c) shows an enlarged view of the frame in which matching data and the matching data are matched extracted from FIG. 11(b).

[0052] Next, the calculation unit 240 compares the illuminance data of the matching data with the illuminance data of the matched frames, and calculates the sum of the differences between the illuminance data of the two. The graph in the circle in Fig. 11(c) shows the difference between the illuminance data of the matching data and the illuminance data of the matched frames, and the sum of the differences is obtained by adding up the differences for one frame. Note that the graph in the circle in Fig. 11(c) has a flat output waveform overall, which indicates that there is little difference between the illuminance data of the matching data and the illuminance data of the matched frames.

[0053] The presence status determination unit 250 compares the sum calculated by the calculation unit 240 with a preset reference value, and determines the presence or absence of the detection target X when the sum exceeds the reference value. Fig. 11 is a graph showing the output value (small waveform) of the illuminance sensor and the difference. That is, as the detection target X approaches the illuminance sensor 200, the shadow of the detection target X becomes larger and the amount of light reaching the illuminance sensor 200 decreases. Therefore, a preset criterion is set for the approach, stationary, and departure of the detection target X based on the following tendency of the illuminance data as shown in the output value of the illuminance sensor 200 in Fig. 12. (1) Approach: Output value decreases. (2) Stationary: The output value remains low. (3) Defection: Output value increases.

[0054] In this embodiment, the sum of the differences for one frame is compared with the reference value, rather than the magnitude of the difference in Fig. 12. The reason for this is that since the illuminance data is acquired in a short period of time, such as 10 msec, a large difference may occur instantaneously due to the influence of disturbances, etc., and in order to eliminate such malfunctions, the sum of the illuminance data for one frame is compared with the reference value.

[0055] When the sum of the calculated differences is greater than the reference value, the presence state determination unit 250 considers that a change has occurred and determines that the state is a presence state. Note that when the detection target X is not present, the same tendency continues to be output, resulting in a state with little change.

[0056] The absence state determination unit 260 detects that a value equivalent to the illuminance data value of the frame before the presence state determination by the presence state determination unit 250 has been output, and determines the completion of the transition from the presence state to the absence state. That is, even when the detection target X moves away from the installed object V, the sum of the differences becomes large and exceeds the reference value, but this makes it impossible to distinguish from the case where the detection target approaches further from the presence determination state at the time of approach. Therefore, in the case of an absence determination, it detects that the illuminance data has reached the state before the presence determination, i.e., the past absence determination, and determines the absence determination.

[0057] [2-2. Operation of the Second Embodiment] When a detection target X approaches an installation V on which the illuminance sensor 200 is installed, the illuminance sensor 200 detects the illuminance caused by the shadow of the detection target X. The illuminance data is stored in the illuminance data storage unit 210 at predetermined time intervals. A process of detecting the approach, stop, and departure of the detection target X and judging the presence or absence of the detection target X relative to the installation V will be described with reference to Figs. 14 and 15.

[0058] 14 is a flowchart showing the approach detection process. The calculation unit 240 compares the matching data with past data and extracts the difference between them (step S41). The calculation unit 240 calculates the sum of the differences from the frame with the smallest error (step S42). It is determined whether the difference is greater than a certain value (step S43).

[0059] If the difference is greater than the fixed value (YES in step S43), the presence state determination unit 250 determines that the user is present. Then, the flow proceeds to the separation detection flow. If the difference is less than the fixed value (NO in step S43), the process of steps S41 to S43 is performed again.

[0060] 15 is a flowchart showing the separation detection process. The calculation unit 240 calculates the difference between the illuminance data before and after the presence determination (step S51). It is determined whether the difference is smaller than a certain value (step S52).

[0061] If the difference is smaller than the fixed value (YES in step S52), the absence state determination unit 260 determines that the user is absent. Then, the process proceeds to the approach detection flow. If the difference is larger than the fixed value (NO in step S52), the process of steps S51 to S52 is performed again.

[0062] [2-3. Effects of the second embodiment] (1) The sensor device of this embodiment has the effect of being able to perform presence / absence determination with high accuracy while realizing space saving and cost reduction in the installation location. In other words, the presence / absence determination is performed by comparing the matching data with past data, and thus detection errors caused by the environment of the installation object V and the characteristics of the detection target X are eliminated compared to the case where a fixed reference value is directly compared with the illuminance data.

[0063] (2) According to the sensor device of this embodiment, an absence determination is made by detecting that the illuminance data has reached the state before the presence determination, i.e., the state of the past absence determination. Therefore, it is possible to clearly distinguish between the movement of the detected object during the presence determination and the absence determination.

[0064] (3) There is no need to provide a dedicated light emitting unit in the illuminance sensor 200, and since the change in the amount of light in the surrounding environment of the installation object V is detected, the configuration of the illuminance sensor 200 can be simplified.

[0065] (4) According to the sensor device of this embodiment, the illuminance sensor 200 has a function as a human sensor, so there is no need to use a separate infrared sensor or ultrasonic sensor, and the approach, stationary state, and departure of the detection target X can be detected by observing the change in illuminance of the illuminance sensor 200 alone. As a result, it is possible to reduce costs and save space in the installation location.

[0066] (5) In this embodiment, by combining the detection information of the existing Doppler sensor 100 and the detection information of the illuminance sensor 200, it is possible to eliminate erroneous recognition caused by the installation environment of the installation object V and the complex or irregular movement of the detection target X, and it is possible to further improve the detection accuracy of the presence or absence of the detection target X in front of the sensor. Furthermore, in addition to the approaching and leaving movements of the detection target X, stable detection is possible even when the detection target X is stationary.

[0067] [3. Third embodiment] [3-1. Configuration of the third embodiment] A third embodiment of the present invention will be described below. The configuration of the third embodiment is such that the Doppler sensor 100 of the first embodiment is further provided with an illuminance sensor 200 that determines the detection target X by using light from an illumination device such as an LED light for displaying products provided in an existing vending machine at night, for example, when the installation object V is a vending machine. Note that a description of parts common to the first embodiment will be omitted.

[0068] In the second embodiment, the change in illuminance caused by the shadow of the detection target X is detected, whereas in the third embodiment, a lighting device or the like provided in the vending machine irradiates light onto the detection target X and detects the reflected light. Therefore, in the second embodiment, the closer the detection target X is to the installation V, the larger the shadow blocking the surrounding light becomes, and the smaller the amount of light captured by the illuminance sensor 200 becomes, whereas in the third embodiment, the closer the detection target X is to the installation V, the greater the amount of light reflected by the detection target X becomes.

[0069] Therefore, in the third embodiment, as shown in Fig. 13, the presence state determination unit 250 determines the presence state when the sum of the differences by the calculation unit 240 is positive, and determines the transition to the absence state when the sum of the differences is negative, which is different from the second embodiment. The other configurations and operations are the same as those of the first embodiment, so the explanation will be omitted.

[0070] [3-2. Effects of the Modification of the Third Embodiment] In the third embodiment having such a configuration, the detection target X is determined using light from a lighting device such as an LED light for displaying products installed in an existing vending machine. Therefore, even at night, when shadows due to natural light cannot be detected unlike during the day, a certain amount of light can be irradiated onto the detection target X and the reflected light can be detected, enabling a more accurate presence / absence determination. In addition, by combining the detection information of the existing Doppler sensor 100 and the detection information of the illuminance sensor 200, it is possible to eliminate erroneous recognition caused by the installation environment of the installation object V and the complex or irregular movements of the detection target X, and the detection accuracy of the presence / absence of the detection target X in the vicinity of the sensor can be further improved. In addition, stable detection is possible even when the detection target X is stationary, in addition to the approaching and leaving movements of the detection target X.

[0071] [4. Other embodiments] The present invention is not limited to the above-described embodiment as it is, and in the implementation stage, the components can be modified and embodied without departing from the gist of the invention. In addition, various inventions can be formed by appropriate combinations of multiple components disclosed in the above-described embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, components from different embodiments may be appropriately combined. The following is one example.

[0072] (1) In the first embodiment, the distance calculation unit 130 performs distance conversion according to a five-level threshold value, but the threshold value does not necessarily have to be five levels. The number of levels is not important as long as it is possible to calculate the slope of the data values ​​that indicates the increase / decrease tendency of multiple distance data values.

[0073] (2) In the first embodiment, the analysis unit 150 determines the correlation between the distance data values ​​when comparing them, but the correlation is not necessarily required. In FIG. 6, the process using the correlation coefficient is described, but as shown in FIG. 7, the approach / leave detection process may be performed without using the correlation coefficient. That is, as in FIG. 6, if the thresholds B to D react (NO in step S12), it is confirmed whether the slope of the data values ​​indicating the increase / decrease tendency of the distance data values ​​is equal to or greater than a certain value (step S21). If the slope of the data values ​​indicating the increase / decrease tendency of the distance data values ​​is not equal to or greater than a certain value (NO in step S21), it is returned to the start, and it is again confirmed whether the thresholds A to D react (step S11). If the slope of the data values ​​indicating the increase / decrease tendency of the distance data values ​​is equal to or greater than a certain value (YES in step S21) and is a negative slope (YES in step S23), it is determined to be an approaching state. If the slope is not a negative slope (NO in step S23), it is determined to be a leaving state. Other processes are the same as those in FIG. 6. In the case of processing that does not use correlation in this way, for example, if the reflected signal extraction unit 120 detects a reflected signal having a value that is significantly different from the output values ​​of the preceding and following reflected signals, it can be excluded as an outlier, thereby achieving a function equivalent to that of determining correlation. Also, analysis can be performed with a certain degree of accuracy by taking the average value of the slopes of multiple distance data values ​​without checking the correlation.

[0074] (3) The sensor device of the present invention is not limited to being installed in a vending machine, but may be installed in lighting, toilets, cars, etc. Furthermore, the detection target is not limited to a person, but may include any object such as a living thing, a car, or a machine.

[0075] (4) The illuminance sensor 200 to be combined with the sensor device of the present invention is not limited to that shown in the second embodiment, and other configurations may also be used. For example, the illuminance sensor 200 of the present invention is not limited to one that does not have a light-emitting unit, and includes illuminance sensors 200 that include a light-emitting unit. When the illuminance sensor 200 includes a light-emitting unit, it is preferable to detect the illuminance of reflected light from the detection target X that is hit by light emitted from the light-emitting unit, as in the third embodiment. [Explanation of symbols]

[0076] X: Detection target V...Installed object 100…Doppler sensor 101...Transmitter 102...Receiving unit 105...Data processing unit 110...Reflected signal extraction section 111…Outlier removal unit 120...Reflected signal storage section 130...Distance calculation section 140...Array storage section 150…Analysis Department 160…Judgment section 200…Illuminance sensor 205...Data processing unit 210...Illuminance data storage unit 220…Matching data setting unit 230…Data update section 240...Arithmetic section 250...Present state determination unit 260…Absence status determination unit

Claims

1. A Doppler sensor including a transmitter that transmits a radio signal to an outside of an installation object and a receiver that receives a reflected signal of the radio signal from a detection target; a reflected signal extracting unit that extracts the reflected signal received by the receiving unit at a predetermined interval; a reflected signal storage unit that stores a plurality of the reflected signals extracted at a predetermined interval by the reflected signal extraction unit; a distance calculation unit that calculates a distance between the installation object and the detection object at the time of extraction of each reflected signal based on the multiple reflected signals stored in the reflected signal storage unit, without using an output value of the reflected signal from the Doppler sensor as it is to determine whether the detection object is present or not; an array storage unit that arrays and stores the plurality of distance data converted by the distance calculation unit in the order in which the reflected signals are received; an analysis unit that compares the plurality of distance data values ​​stored in the array storage unit, and analyzes the approach, stop, and departure of the detection target from the installation object based on a gradient of a data value that indicates an increase / decrease tendency of the plurality of distance data values; A sensor device comprising a determination unit which determines the presence or absence of the detection target relative to the installation object based on the analysis result of the analysis unit.

2. The sensor device described in claim 1, characterized in that when comparing the multiple distance data values, the analysis unit determines the correlation between the multiple distance data values, and analyzes the approach, stopping, and departure of the detection target from the installation object based on this correlation and the slope of the data values ​​that indicate the increase / decrease tendency of the multiple distance data values.

3. The sensor device according to claim 1 or 2, characterized in that the reflected signal extraction unit includes an outlier removal unit that compares the reflected signal with a predetermined threshold, determines that the reflected signal that meets a predetermined condition is an outlier signal, and removes it from the reflected signals to be extracted.

4. The sensor device according to claim 1 or 2, wherein the determination unit continues to hold the presence determination as the approaching or stationary motion of the detection target from the time of the presence determination to the time of the absence determination.

5. A vending machine comprising the sensor device according to claim 1 or 2.

6. 6. The vending machine of claim 5, further comprising an illuminance sensor.

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