JP2003242596A - Vehicle detection system - Google Patents

Abstract

(57) [Problem] To provide a vehicle detection system capable of detecting a vehicle with a high detection accuracy by reducing erroneous recognition of the vehicle and lower power. A temperature detection sensor detects infrared rays emitted from a vehicle or the like by a thermopile element to detect a temperature. The temperature processing unit 12 compares the temperature with the background temperature and activates the measurement sensor 11 when the temperature difference is equal to or greater than a specified value. The presence / absence of the vehicle is determined by comparing the physical quantity detected by the measurement sensor 11 with the background value in the sensing processing unit 13. The temperature detection sensor 10 is operated intermittently by the timer 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle detection system and a vehicle detector. In particular, the present invention relates to a vehicle detection system and a vehicle detector that are most suitable for detecting a vehicle with high accuracy and low erroneous vehicle recognition and lower power consumption.

[0002]

2. Description of the Related Art Conventionally, loop detectors, ultrasonic detectors and the like are well known as vehicle detectors for detecting vehicles in order to check traffic flow such as traffic volume and occupancy.

A loop detector detects a vehicle by burying a loop coil in a road and detecting a change in inductance when the vehicle passes over the coil.

Generally, the ultrasonic detector uses a so-called active sensor which emits ultrasonic waves by itself and senses the reflected waves thereof. The ultrasonic detector transmits ultrasonic waves, reflected waves from vehicles and reflected waves from roads. The vehicle is detected by detecting the time difference until and are returned. An example of such an ultrasonic detector is disclosed in Japanese Patent Laid-Open No. 60-78373.

[0005]

However, the conventional vehicle detector has the following problems. The loop detector needs to be buried in the road with the loop coil, and the burying work is required, and it is difficult to secure the burying space in a bridge or the like, which may not be applicable.

On the other hand, the ultrasonic detector (1) is difficult to detect a vehicle accurately when it is installed on the side of the road to improve the appearance. (2) The power consumption is high and the cost is high. There is a problem that becomes. (1) Generally, ultrasonic detectors should be positioned so that the transmitting / receiving part is located almost directly above the vehicle passing the road so that the ultrasonic wave can be transmitted almost perpendicularly to the vehicle passing the road. Is installed. Therefore, in the ultrasonic detector, a horizontal member is attached to a pillar near the road, and the transmitting / receiving unit is fixed to the horizontal member so that the transmitting / receiving unit faces almost directly below the road or vehicle. Therefore, the horizontal member needs to have a length that allows the ultrasonic detector to be projected to the middle of the road so that the ultrasonic detector is located almost directly above the vehicle. However, since the horizontal member projects upward in the middle of the road and is attached to the pillar, not only is the appearance impaired, but the installation cost is high. In particular, when there are multiple lanes on the road, a long horizontal member that connects the columns on both sides of the road is required to install the vehicle detector for each lane, and the above problem is remarkable. .

[0007] Therefore, rather than removing such a relatively long horizontal member or shortening the horizontal member, the ultrasonic detector is positioned diagonally above the vehicle instead of the so-called direct installation as described above. It is conceivable to attach it to the support so that it is installed in a so-called side fire type. However, in this case, since the wave transmitter / receiver unit is facing diagonally downward with respect to the road and vehicle, it is affected by wind and rain and multiple reflections.
There is a risk of misidentifying the vehicle. Specifically, when the rain falling sideways hits the ultrasonic transducer and the transducer vibrates at the natural vibration frequency, or the reflected wave returned by multipath other than the reflected wave directly returned from the vehicle was received. In some cases,
It may be determined that there is a vehicle.

(2) The ultrasonic detector must be at least operated until it receives the reflected wave of the transmitted ultrasonic wave. Further, in order to accurately check the occupancy rate and to detect the vehicle with high accuracy without missing the number of detected vehicles, it is preferable to detect as many times as possible for one vehicle. Here, the time from the ultrasonic detector to the ultrasonic wave being transmitted to an object located 5 m below and the reflected wave returning is usually about 30 ms (milliseconds). And
Since the processing time for determining the presence / absence of a vehicle is about 30 ms, the conventional ultrasonic detector can detect 60 m per vehicle detection.
s required. Therefore, even if the ultrasonic detector is continuously operated at 60 ms intervals, for example, a vehicle length of 5 m and a speed of 100 km / h (100 km / h
A vehicle traveling at ≈28 m / s) can detect this vehicle only three times within the time of 223.2 ms when it passes the 1.2 m monitoring range. Therefore,
In order not to reduce the detection accuracy, it is necessary to continuously operate the ultrasonic detector, resulting in a large power consumption. As described above, in the ultrasonic detector, the detection interval is limited by the distance to the object to be detected and the sound velocity, and it is difficult to perform the intermittent operation that may lower the detection accuracy.

SUMMARY OF THE INVENTION Therefore, a main object of the present invention is to provide a vehicle detection system which reduces false recognition of a vehicle, has high detection accuracy, and can detect a vehicle with lower power consumption.

Another object of the present invention is to provide a vehicle detector which is optimal for the above vehicle system without impairing the appearance.

[0011]

The present invention achieves the above object by stepwise determining the presence or absence of a vehicle using two sensors, a temperature detecting sensor and a measuring sensor, which use means for detecting infrared rays. That is, the vehicle detection system of the present invention is characterized by having the following configuration. A temperature detection sensor that does not emit infrared rays by itself but detects the infrared rays emitted by the detection target and detects the temperature. First storage means for storing a temperature other than that of the vehicle as a background temperature. The temperature obtained from the temperature detection sensor is compared with the background temperature read from the first storage unit, and if the temperature difference is a specified value or more, a sensor other than the temperature detection sensor and a physical quantity from the detection target. Judgment means for activating a measurement sensor that detects the contactlessly. Second storage means for storing a physical quantity obtained from other than the vehicle as a background value. Vehicle presence / absence determining means for comparing the physical quantity obtained from the activated measurement sensor with the background value read from the second storage means and determining the presence of the vehicle when the difference is equal to or more than a specified value.

In the first step of the present invention, the presence / absence of a vehicle is determined by using a temperature detection sensor which senses infrared rays to detect the temperature. When the difference between the temperature obtained from the vehicle detection sensor and the background temperature is equal to or greater than the specified value, it is determined that there is a vehicle and the measurement sensor is activated. If the temperature difference between the two is less than the specified value, it is determined that there is no vehicle. At this time, when the background temperature is set to a fixed value, for example, the processing is ended by deleting the obtained temperature. When the background temperature is used as the variation value, processing such as storing the obtained temperature for use as the background temperature is performed. Then, as a second step, when the temperature detection sensor determines that a vehicle is present, the measurement sensor is activated, and the presence or absence of the vehicle is finally determined based on the sensing result of the measurement sensor. By thus determining the presence / absence of the vehicle stepwise, it is possible to improve the detection accuracy and reduce the false recognition of the vehicle.
In addition, because the detection accuracy can be improved by two-step detection, it is not necessary to install the vehicle detector directly downwards toward the road surface unlike the conventional ultrasonic detector, and it is installed on the side of the vehicle. Even if this occurs, it is possible to detect the vehicle with high accuracy.

In particular, the system of the present invention uses the means for detecting infrared rays in the first-stage detection, whereby the sensor can be operated intermittently without lowering the detection accuracy. The time required for the infrared rays emitted from the detection target to reach the temperature detection sensor is on the order of ns (nanosecond), which is substantially negligible as compared with the conventional ultrasonic detector. Therefore, the present invention does not require continuous operation unlike the conventional ultrasonic detector, and can intermittently operate the temperature detection sensor. Further, in the present invention, since the means for passively detecting infrared rays is used, the power consumption is smaller than that of the active sensor used in the conventional ultrasonic wave detection. As described above, according to the present invention, the power consumption is reduced by using the passive sensor having relatively low power consumption and intermittently operating the temperature detection sensor and the measurement sensor. Further, according to the present invention, since the vehicle is sequentially monitored by the two sensors of the temperature detection sensor and the measurement sensor, the vehicle can be accurately detected even when the temperature detection sensor and the measurement sensor are intermittently operated.

The present invention will be described in more detail below. In the present invention, the temperature detecting sensor is a so-called passive sensor that includes an element that does not emit infrared rays by itself and senses infrared rays emitted by a detection target, and that can detect temperature with this element. The above-mentioned element is preferably one that can be heated by the thermal effect of infrared rays and can detect a change in electrical properties caused by a rise in temperature. As such an element,
In particular, it is preferable to use a thermopile element that outputs a temperature change generated in a thermocouple by infrared rays as a thermoelectromotive force.

The measuring sensor is not a passive sensor like a temperature detecting sensor but a so-called active sensor, and for example, an ultrasonic sensor or an optical sensor is preferable. Specifically, the ultrasonic sensor detects the time until the ultrasonic wave is transmitted and the reflected wave is returned.The optical sensor emits an infrared pulse and the reflected wave is returned. What detects the time of is preferable. In addition, as the measurement sensor, an imaging sensor that detects an image captured by a camera can be used. The camera used for the image pickup sensor is preferably a CCD camera.

It is desirable to control the temperature detecting sensor by using a timer or the like to operate intermittently. It is advisable to operate the temperature detection sensor for a fixed time period in a fixed cycle by a timer to detect infrared rays. Further, the measurement sensor may similarly control the detection interval by a timer, but it is preferable that the measurement sensor is activated in conjunction with the temperature detection sensor and is operated for a time required for vehicle detection.
At this time, it is preferable to set the vehicle detection time by the measurement sensor to the time during which the temperature detection sensor is not operating in a constant cycle of the timer. That is, it is preferable that the detection of the vehicle by the temperature detection sensor and the detection of the vehicle by the measurement sensor are performed in a constant cycle of the timer. For example, when the period of the timer is set to 60 ms like the detection time of the conventional ultrasonic detector, it is preferable to use an optical sensor whose measurement time can be substantially ignored. At this time, the operation time of the measurement sensor can be halved while the number of times the vehicle passes through the monitoring range on the road is detected almost the same as the conventional ultrasonic detector.

On the other hand, when a measuring sensor such as an ultrasonic sensor having a relatively long measuring time is used, if both the temperature detecting sensor and the measuring sensor detect the vehicle in one cycle of the timer, the cycle becomes relatively long. It is possible. Therefore,
When the period of the timer is, for example, 60 ms, the temperature detection sensor may be stopped while the measurement sensor is detecting the vehicle. Then, when the detection of the vehicle by the measurement sensor is completed, the temperature detection sensor may be activated again. At this time, it is preferable to operate the measurement sensor until the determination that there is no vehicle is obtained without lowering the occupancy accuracy. At this time, if the monitoring range is extremely large, multiple vehicles may be mistaken for one vehicle. Therefore, it is preferable that the monitoring range is a range in which a plurality of vehicles are not mistakenly recognized as one vehicle, for example, about 1.2 m. Note that when the timer period is lengthened, the operating time of the sensor is shortened, so that the occupancy rate accuracy is slightly lowered, but the power consumption can be further reduced. Further, the temperature detection sensor may be operated while the measurement sensor detects the vehicle. At this time, if the temperature change is equal to or more than the specified value, a command to activate the measurement sensor is issued, but since the measurement sensor is already operating, this command may be ignored. Then, when the temperature change is equal to or more than the specified value and the measurement sensor is not operating, the measurement sensor may be activated.

For the background temperature and background value used as a criterion for the detection of the vehicle, a fixed value may be set in advance for each season or each day time, and the fixed value may be set and used. It is preferable to use the one based on the data detected by the temperature detection sensor or the measurement sensor. At that time, it is preferable to detect the temperature and physical quantity from other than the vehicle at any time and use this value. At this time, since the background temperature and the background value, which are comparison criteria, are close to the values of the actual environment, more precise detection can be performed. As background temperature and background value,
The value detected immediately before the comparison may be used, but in an actual environment, an instantaneous change may occur due to some influence, so if only the value obtained in one detection is used, the vehicle There is a risk of misunderstanding. Therefore, it is preferable to detect and accumulate the background level a plurality of times and use the average value as the background temperature and the background value. At this time, it is preferable that the measurement sensor be configured so that it can be operated by the timer means in a fixed cycle for a fixed time. Even when the background value is detected, the power consumption can be further reduced by operating the measurement sensor intermittently.

As described above, when the background value is set to a value based on the data of the measurement sensor, the first instruction for interlocking the measurement sensor with the temperature detection sensor to make it detectable and the measurement sensor by the timer means. It is conceivable that it overlaps with the second instruction that makes the state detectable for detecting the background value. In this case, it is preferable that either one be prioritized.

The counting result obtained from the vehicle determining means may be sent to a signal controller or a management center by wire, but the system further comprises wireless communication means for transmitting the counting result wirelessly. , May be transmitted wirelessly. At this time, it is preferable to use a timer or the like to perform transmission at a fixed cycle for a fixed time because the power can be further reduced.

Such a vehicle detection system of the present invention includes:
It is preferable to use a vehicle detector that detects a vehicle passing through a surveillance range on the road and that includes the following sensors. (1) A temperature detection sensor that detects the temperature using a thermopile element that detects infrared rays emitted by the vehicle from the side of the road. (2) A measurement sensor that detects a physical quantity from the vehicle in a non-contact manner by means other than the thermopile element.

The vehicle detector of the present invention is installed in a so-called side fire type on a pillar provided on the roadside to monitor the vehicle from the side of the road. Specifically, when the mounting position is equal to or higher than the height of the vehicle from the road surface, the vehicle detector is mounted on the column so that the vehicle detector faces diagonally downward with respect to the road or the vehicle, and the vehicle is monitored from diagonally above. When the mounting position is less than the height of the vehicle from the road surface, the vehicle detector is mounted on the column so that the vehicle detector is oriented horizontally with respect to the vehicle, and the vehicle is monitored almost from the side.

Since the vehicle detector of the present invention detects the vehicle stepwise by the temperature detection sensor and the measurement sensor, even if the vehicle detector is installed not on the vehicle passing directly on the road but on the side of the road, It is possible to detect with high accuracy without misunderstanding. Further, the vehicle detector of the present invention does not need to use any horizontal member at the time of installation like the conventional ultrasonic detector, or even if the horizontal member is used, it is shorter than the conventional horizontal member. Well, it does not spoil the aesthetics.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. (Embodiment 1) FIG. 1 is a functional block diagram of a vehicle detection system of the present invention that transmits a totaling result by wire. This system detects the temperature from the infrared rays emitted by a vehicle passing through the monitoring range, compares this temperature with the background temperature, and if the temperature difference is more than a specified value, activates the measurement sensor and detects the physical quantity and the background. The presence or absence of the vehicle is determined by comparing the value with the value. The specific components are as follows.

(1) (Temperature Detection Sensor 10) This is a sensor for detecting the temperature by sensing the infrared rays emitted by the detection target such as a vehicle. In this example, the thermopile element 10a was used for sensing infrared rays in the temperature detection sensor 10. Further, the temperature detection sensor 10 is powered on / off by the timer 1 at a constant cycle.

(2) (Measurement sensor 11) A sensor that detects a physical quantity from a detection target such as a vehicle without contact. In this example, an ultrasonic sensor that transmits ultrasonic waves and detects the time until the reflected waves are returned is used. This measurement sensor measures the time until the ultrasonic waves transmitted to the background (roads, etc.) other than the vehicle return, and the time until the ultrasonic waves transmitted to the vehicle return. The power supply for operating the measurement sensor associated with the temperature detection sensor is performed by the power supply. Turning on the power of the measurement sensor 11 is controlled by a temperature processing unit described later, and turning off the power is controlled by a sensing processing unit described later. Further, in this example, the measurement sensor 11 is controlled by the timer 2 so as to be periodically operated for a certain period of time in order to obtain the background value to be compared with the time obtained from the vehicle.
(Power ON / OFF). In this example, as the background value, a background level is periodically detected by the timer 2 for a certain period of time, accumulated, and the average thereof is used.

(3) (Temperature processing unit 12) The temperature obtained from the temperature detection sensor 10 is stored, compared with the background temperature, the temperature other than that of the vehicle is accumulated and averaged to obtain the background temperature. It is a processing unit that performs processing. More specifically, the first memory that stores the temperature other than the vehicle as the background temperature (first storage means), comparing the temperature obtained from the temperature detection sensor 10 and the background temperature read from the memory,
When the temperature difference is equal to or more than the specified value, the measuring sensor 11 is provided with a determination means for starting. A central processing unit (CPU) is appropriately used for these processes.

(4) (Sensing processing unit 13) The time obtained from the measurement sensor 11 is stored, compared with the background value, the time from other than the vehicle is accumulated and averaged to obtain the background value. It is a processing unit that performs processing. More specifically, the second memory (second storage means) that stores the time obtained from other than the vehicle as the background value, the activated measurement sensor 11
And the background value read from the second memory
(Time) is compared, and if the difference is greater than or equal to a specified value, a vehicle presence / absence determining unit for determining the presence of a vehicle is provided. A central processing unit (CPU) is appropriately used for these processes.

In addition, in this example, a solar cell unit 14 is provided for supplying power to each sensor 10, 11 and processing units 12, 13.
Power is supplied by 14a, but a normal battery or the like may be used.

In such a vehicle detection system of the present invention, when the temperature detection sensor 10 is activated by the timer 1, the thermopile element 10a in the temperature detection sensor 10 senses infrared rays emitted by the detection target. The electromotive force generated in the thermopile element 10a is amplified by the amplifier 10b, sent to the temperature processing unit 12, converted into a digital signal by the A / D converter 12a, and the temperature is read. This temperature is compared with the background temperature, and if the temperature difference is equal to or greater than the specified value, the measurement sensor 11 is activated. The time obtained from the measurement sensor 11 is sent to the sensing processing unit 13, and this time is compared with the background value to determine the presence or absence of a vehicle. Then, the data obtained from the sensing processing unit 13 is aggregated into the sensing aggregation result,
Wired to signal controllers and traffic control centers.

The operation procedure of vehicle detection by the above system will be specifically described. 2 is a flowchart showing a control procedure of the timer 1, FIG. 3 is a flowchart showing a processing procedure in the temperature processing unit, FIG. 4 is a flowchart showing a processing procedure in the sensing processing unit, and FIG. 7 is a control procedure of the timer 2. It is a flowchart showing.

First, the timer 1 for intermittently operating the temperature detecting sensor will be described (see FIG. 2). Timer 1 is 1ms
It counts up in cycles (step 20) and controls the ON / OFF of the temperature detection sensor power in 60 ms cycles. Turn on the power of the temperature detection sensor in 30 ms of the 60 ms cycle to start operation, turn on the power for 30 ms of 30 to 60 ms to detect infrared rays (step 21), and turn off the power when it reaches 60 ms. Do
(Step 22). Further, the processing of the temperature processing unit is started in 40 ms (step 23). And when it reaches 60ms, reset
(Step 24), a new count-up is started, and this is repeated. In this example, the temperature sensor is turned off while the measurement sensor is detecting the vehicle, that is, when the power source of the measurement sensor is on.
Leave. Therefore, when the count-up is started and the power of the measurement sensor is OFF,
And 23. On the other hand, if the power source of the measurement sensor is ON, the temperature detection sensor is turned OFF (step 22). In addition,
In this example, the processing start time (40 ms) of the temperature processing unit is delayed by 10 ms from the operation start time (30 ms) of the temperature detection sensor, but it is of course possible to make it simultaneous. In addition, the count-up cycle, the power-on start time and operation time of the temperature detection sensor, the reset cycle, and the like may be changed as appropriate.

Next, the processing of the temperature processing section will be described.
(See Figure 3). With the operation of the temperature detection sensor by the timer 1, the process of the temperature processing unit starts (step 30). In the temperature processing unit, the electromotive force obtained from the temperature detection sensor is sent,
The temperature is read from this electromotive force (step 31). And
The read temperature is compared with the background temperature stored in the first memory as described later (step 32). If the difference between the read temperature and the background temperature read from the first memory (temperature change) is more than the specified value, it is considered that there is a vehicle, so turn on the power of the measurement sensor and start it for more detailed investigation. Simultaneously with (step 33), the process of the sensing processor is started (step 34). In this example, the processing start time of the sensing processing unit is delayed by 10 ms from the operation start time of the measurement sensor, but it is of course possible to make it simultaneous.

On the other hand, if the difference (temperature change) between the read temperature and the background temperature read from the first memory is less than the specified value, it is considered that there is no vehicle. That is, the temperature detection sensor
It means that the background (road etc.) is detected. Therefore, "no vehicle" is written in the result of the detection and aggregation (step 35). Then, the read temperature is stored as a background level (step 36) and accumulated, and the average value of the past 100 times is stored as the background temperature in the first memory (step 37).

Next, the processing of the sensing processing section will be described.
(See Figure 4). The sensing processing unit starts the processing when the measurement sensor for detecting the vehicle is started (power ON), and when the measurement sensor power is supplied to detect the background value described later.
There are two cases in which the process is started with turning on. In this example, when the start of both processes overlaps, the process for detecting the vehicle is prioritized.

With the activation of the measurement sensor, the processing of the sensing processing unit is started (step 40). In the sensing processing unit, the physical quantity obtained from the measurement sensor (in this example, the time until the reflected wave of the transmitted ultrasonic wave returns) is sent and read (step 41). Then, when the power source of the measurement sensor is ON, processing for vehicle detection is performed. That is, the read physical quantity (sensing result) is compared with the background value stored in the second memory (step 42). Physical quantity read
(In this example, the time until the reflected wave of the ultrasonic wave sent to the vehicle returns) and the background value read from the memory (in this example, the reflected wave of the ultrasonic wave sent to other than the vehicle returns If the difference from the arrival time) is equal to or greater than the specified value, it is determined that there is a vehicle (step 43), and “Vehicle is present” is written in the detection count result (step 44). Then, in this example, when it is determined that there is a vehicle, until the determination that there is no vehicle is obtained,
Keep the measuring sensor activated. Therefore, in the case of "there is a vehicle", the processing of the sensing processing unit is started again (step 40). Also, while the power of the measurement sensor is ON,
Turn off the power of the temperature measurement sensor as described above.

On the other hand, if the difference between the read physical quantity and the background value read from the second memory is less than the specified value, it is determined that there is no vehicle (step 45), and the result of sensing and counting is "no vehicle".
And write (step 46).

The result of sensing and counting obtained in steps 44 and 46 is sent to a signal controller or the like via a wire (step 4
7). After that, turn off the power of the measurement sensor (step
48). That is, in this example, when the determination “no vehicle” is obtained, the power supply of the measurement sensor is turned off.

In this example, the monitoring range is 1.2 m, the ultrasonic sensor is used as the measurement sensor, and the temperature detection sensor is stopped until the determination that there is no vehicle is obtained. However, if the cycle of the timer 1 is set to be long, for example, about 80 ms, vehicle detection by both the temperature detection sensor and the ultrasonic sensor can be performed within the cycle of the timer 1. Alternatively, when an optical sensor is used as the measurement sensor, vehicle detection by both the temperature detection sensor and the measurement sensor can be performed in the cycle of the timer 1 of 60 ms.
At this time, since the vehicle can be detected using the measurement sensor while the temperature detection sensor is not operating, the measurement sensor is
After determining the presence or absence of the vehicle, the power may be turned off.
FIG. 5 is a flowchart showing the control procedure of the timer 1 ′ when the power is turned off after determining the presence / absence of the vehicle, and FIG.
4 is a flowchart showing a processing procedure for turning off the power after determining the presence or absence of a vehicle. In the figures, the same symbols indicate the same steps. Timer 1'as shown in Figure 5
Performs the same process as the timer 1 shown in FIG. 2 except that the process for determining whether the power source of the measurement sensor is ON is not performed. Further, the processing of the sensing processing unit shown in FIG. 6 is similarly performed up to steps 44 and 46 in the processing of the sensing processing unit shown in FIG. That is, after determining the presence or absence of a vehicle (steps 43 and 45), the result is written in the sensing count result (steps 44 and 44).
46). The result of sensing and counting obtained from steps 44 and 46 is sent to a signal controller or the like via a wire (step 47). After that, the power supply of the measurement sensor is turned off (step 48).
That is, in this example, the power supply of the measurement sensor is turned off when both of the determinations “with vehicle” and “without vehicle” are obtained.

Next, an operation procedure for detecting the background value will be described (see FIGS. 4 and 7). In this example, the background value is the timer
2 by periodically operating the measurement sensor (power ON),
The time from the background (road etc.) other than the vehicle is detected. The obtained time is sent to the sensing processing unit and read.
(Step 41). Then, when the power source of the measurement sensor is OFF, processing for setting the background value is performed. That is, the read physical quantity (sensing result) is stored as a background level (step 49a) and accumulated, and the average value of the past 100 times is stored as a background value in the second memory (step 49b).

The timer 2 counts up at a cycle of 1 ms (step 50), and at the cycle of 10 s (seconds), the power of the measurement sensor is turned off.
Control N / OFF. Within 10s cycle, at the same time as counting up (0ms), turn on the power of the measurement sensor to start operation, and
Turn on the power for 100 ms (~ 100 ms) to detect the physical quantity (step 51), and turn off the power when 100 ms is reached.
(Step 52). In addition, the processing of the sensing processing unit is started for 10 ms (step 53). Then, when it reaches 10 seconds, it is reset (step 54), a new count-up is started, and this is repeated. In this example, the processing start time of the sensing processor (10ms)
Is delayed 10 ms from the operation start time (0 ms) of the measurement sensor, but it is of course possible to do so at the same time. Further, the count-up cycle, the power-on start time and operation time of the measurement sensor, the reset cycle, and the like may be changed as appropriate.

The ultrasonic sensor used in this example determines the presence / absence of a vehicle on the basis of the time until the reflected wave of the ultrasonic wave transmitted to the background (road etc.) other than the vehicle returns (background value). However, the same may be applied when an optical sensor is used as the measurement sensor. That is, the time until the reflected wave of the infrared pulse transmitted to the road is returned may be used as a reference. When using an image sensor as the measurement sensor, CC
The image taken by the D camera is processed to detect the brightness,
It is recommended to use the brightness when there is no vehicle as a reference.

As described above, in the vehicle detection system of the present invention, the power supply of the temperature detection sensor is controlled by the timer 1 and the power supply of the measurement sensor is turned on in conjunction with the temperature detection sensor.
By controlling / OFF as well, both sensors are operated intermittently to reduce power consumption. In addition, in this example, in order to detect the vehicle more accurately, the background value based on the data of the measurement sensor is used, but in the process for detecting the background value, the measurement sensor by the timer 2 is used. It also controls the ON / OFF of the power of to operate intermittently.
With such a configuration, the present invention can realize highly accurate vehicle detection with lower power consumption.

(Embodiment 2) In the above example, the case where the result of sensing and counting is transmitted to the signal controller or the management center by wire has been described. However, the wireless communication unit (wireless communication means) is provided and the sensing and counting is performed. The transmission of the result may be performed wirelessly using light or radio waves. FIG. 8 is a functional block diagram of the vehicle detection system of the present invention including a wireless communication unit. The basic structure is
Same as 1. The wireless communication unit 15 includes a wireless control unit 15a and a transmission / reception unit 15b such as an antenna, and the sensing processing unit 13
The totalized results sent from are sent to a signal controller, management center, etc. In this example, the timer 3 is used to perform transmission in a fixed cycle for a fixed time. 9 shows timer 3
10 is a flowchart showing the control procedure of FIG. 10, and FIG. 10 is a flowchart showing the processing procedure in the wireless control unit.

As shown in FIG. 9, the timer 3 counts up at a cycle of 10 ms (step 70) and controls ON / OFF of the power supply of the transmission / reception unit at a cycle of 60 s. 0 to 500ms in 60s cycle
The power of the transmission / reception unit is turned on for 500 ms to transmit the sensing processing result (step 71), and when the time has reached 500 ms, the power of the transmission / reception unit is turned off to stop the transmission (step 72). Also, 100
Instruct ms to start processing of the wireless control unit (step 73). Then, when it reaches 60 s, it is reset (step 74), a new count-up is started, and this is repeated. In this example, the processing start time (100 ms) of the wireless control unit is delayed by 100 ms from the operation start time (0 ms) of the transmission / reception unit, but it is of course possible to make it simultaneous.

As shown in FIG. 10, when the power of the transmission / reception unit is turned on, the process of the wireless control unit starts (step 80). The wireless control unit reads the result of the sensing and counting obtained from the sensing processing unit (step 81) and transmits the read result via the transmitting / receiving unit (step 82). After the transmission, the result of the sensing and counting stored in the memory is cleared (step 83). It should be noted that it is also possible to accumulate the sensing and counting results without clearing them, and transmit only the latest sensing and counting results.

In the vehicle detection system of the present invention as described above, the timer 3 intermittently transmits the result of the detection and counting to the signal controller, etc., so that the vehicle of a lower power consumption and higher accuracy can be used as compared with the wired type. Detection can be realized. The timers 1 to 3 shown in the first and second embodiments may or may not be synchronized with each other.

Next, an application example of the vehicle detection system of the present invention will be described. FIG. 11 is a schematic view showing a state in which the vehicle detector of the present invention is attached to a pillar near the road. The present invention vehicle detector
1 is a temperature detection sensor 10 that detects a temperature using a thermopile element that detects infrared rays emitted by the vehicle 103 from the side of the road 101, and a measurement sensor that detects a physical quantity from the vehicle in a non-contact manner by means other than the thermopile element. 11 and housing 2
Equipped inside.

The casing 2 has a desired height W from the surface of the road 101 (about 5.5 m in this example), and the width W of the monitoring range 102 (the rectangular portion surrounded by the broken line in FIG. 11) on the road 101 is desired. Size of
(1.2 m in this example) is attached at a certain angle with respect to the axial direction of the pillar 100 near the road 101. At this time, both sensors 10 and 11 in the housing 2 detect a physical quantity from a vehicle or the like from a side of the road 101, not from directly above, as in a conventional ultrasonic detector. However, the present invention vehicle detector 1
Equipped with a temperature detection sensor 10 and a measurement sensor 11, even if installed on the side of the road, there is little false recognition of the vehicle like a conventional ultrasonic detector, and excellent detection at low power is possible. It can be carried out.

If the vehicle detector is provided with one thermopile element, one lane can be monitored. Therefore, when the position of the vehicle detector is adjusted so as to be within a monitoring range in which a plurality of lanes can be monitored, a vehicle that has passed one of the lanes can be detected even from the side of the road.

When monitoring a plurality of lanes, for example, a temperature detecting sensor having a plurality of thermopile elements and a plurality of measuring sensors may be provided in the housing. By providing each thermopile element and measurement sensor at different positions, it is possible to realize vehicle detection of a plurality of lanes with one housing even if they are installed on the side of the road. Therefore, unlike the conventional ultrasonic detector, a relatively long horizontal member is not required at the time of installation, and the appearance is not spoiled.

A control box 16 having a temperature processing section, a sensing processing section, and the like, and a solar cell section 14 for supplying power to the sensors 10, 11 and the processing section are attached to the column 100. The control box 16 may be provided with a battery instead of the solar cell unit 14, and a wireless communication unit when the sensing and counting result is not transmitted by wire.

[0053]

As described above, according to the vehicle detection system of the present invention, a plurality of temperature detection sensors and measurement sensors are used to judge the vehicle in multiple stages, so that the vehicle is less likely to be erroneously recognized and has high accuracy. It is possible to obtain an excellent effect that the vehicle detection can be performed by. In particular, by detecting infrared rays, the time required to detect a vehicle can be extremely shortened as compared with the case where a conventional ultrasonic detector is used to detect a vehicle. Therefore, the sensor can be operated intermittently. And,
Since the temperature detection sensor uses a passive sensor that does not emit infrared rays by itself, it consumes less power than a sensor using an active sensor such as a conventional ultrasonic detector. Therefore, power consumption can be further reduced and cost can be reduced.

Further, the vehicle detector of the present invention has a high detection accuracy by using the temperature detecting sensor and the measuring sensor, and it is almost vertical to the road surface by using a horizontal member as in the prior art. Even if it is installed on the side of the road, the vehicle can be sufficiently detected. Therefore, the vehicle detector of the present invention,
Since it can be installed without using a relatively large horizontal member as in the past, it is presumed that the installation conditions are loose and the applicable range is wide. Further, since a relatively large horizontal member is not used, the appearance is not spoiled and the installation cost is not increased.

[Brief description of drawings]

FIG. 1 is a functional block diagram of a vehicle detection system of the present invention.

FIG. 2 is a flowchart showing a control procedure of timer 1.

FIG. 3 is a flowchart showing a processing procedure in a temperature processing unit.

FIG. 4 is a flowchart showing a processing procedure in a sensing processing unit.

FIG. 5 is a flowchart showing a control procedure of a timer 1 ′.

FIG. 6 is a flowchart showing a processing procedure for turning off the power after determining the presence or absence of a vehicle.

FIG. 7 is a flowchart showing a control procedure of timer 2.

FIG. 8 is a functional block diagram of the vehicle detection system of the present invention including a wireless communication unit.

FIG. 9 is a flowchart showing a control procedure of a timer 3.

FIG. 10 is a flowchart showing a processing procedure in a wireless control unit.

FIG. 11 is a schematic view showing a state in which the vehicle detector of the present invention is attached to a pillar near the road.

[Explanation of symbols]

1 Vehicle detector 2 Housing 10 Temperature detection sensor 10a Thermopile element 10b Amplifier 11 Measurement sensor 12 Temperature processing unit 12a A / D converter 13 Sensing processing unit 14
Solar cell unit 14a Solar cell 15 Wireless communication unit 15a Wireless control unit 15
b Transmitter / receiver 16 Control box 100 Pillar 101 Road 102 Monitoring range 103 Vehicle

Claims (4)

[Claims] 1. A temperature detection sensor that does not emit infrared rays by itself but detects infrared rays emitted by a detection target to detect a temperature, first storage means that stores a temperature other than that of a vehicle as a background temperature, and the temperature detection sensor. When the temperature difference is equal to or more than a specified value by comparing the obtained temperature with the background temperature read from the first storage means, a sensor other than the temperature detecting sensor detects a physical quantity from a detection target in a non-contact manner. A determination means for activating the measurement sensor, a second storage means for storing a physical quantity obtained from other than the vehicle as a background value, a physical quantity obtained from the activated measurement sensor, and a background value read from the second storage means. And a vehicle presence / absence determining means for determining the presence of a vehicle when the difference is equal to or more than a specified value. 2. The vehicle detection system according to claim 1, wherein a thermopile element is used to detect infrared rays. 3. The vehicle detection system according to claim 1, further comprising a wireless communication unit that wirelessly transmits the counting result obtained from the vehicle determination unit. 4. A vehicle detector for detecting a vehicle passing through a monitoring range on a road, the temperature detecting sensor detecting a temperature using a thermopile element for detecting infrared rays emitted from the side of the road, A vehicle detector comprising a measurement sensor that detects a physical quantity from a vehicle in a non-contact manner by means other than the thermopile element.