JP2001256590A - Device for detecting crossing pedestrian - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively and accurately distinguish a crossing pedestrian on the road from the other passers, a fixed obstacle, etc. SOLUTION: A processing part 14 of this crossing pedestrian detecting device 10 controls an ultrasonic wave transmitting part 18 so as to transmit ultrasonic waves within a sensing area via an input-output transformer 20 and an ultrasonic transmitter-receiver 22. Reflection waves reflected by hitting against an object within the sensing area are caught by the transmitter-receiver 22 and are received by an ultrasonic wave receiving part 24 via the transformer 20. The part 14 detects where the object exists within the sensing area by performing arithmetic processing on the basis of transmission and reception waves. When the object exists, whether or not the object stops >=2 seconds within the area of a fixed range is decided, and when the stopped object further stays in the same state >=5 seconds, the part 14 attempts not to detect the object as an object by defining the object as a fixed obstacle. Unless the object is a fixed obstacle, the object is recognized as a crossing pedestrian being a sensing target to perform target detection processing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traversing person detecting device, and more particularly, to transmitting a ultrasonic wave toward a certain area on a road near a pedestrian crossing, and traversing the object according to the position of an object detected from the reflected wave. The present invention relates to a crosser detection device that detects a person.

[0002]

2. Description of the Related Art Conventionally, an ultrasonic sensor or the like has been used as a device for transmitting an ultrasonic wave toward a certain area and receiving a reflected wave coming back upon hitting the object in the area to detect the object. ing. This type of ultrasonic sensor is used for investigating the traffic volume of pedestrians traveling on a sidewalk and the traffic volume of vehicles on a road, and the like. For example, the former ultrasonic sensor includes a pedestrian detector and the like. . Therefore, conventionally, a pedestrian sensor is installed on a road near a pedestrian crossing, thereby determining the presence or absence of a pedestrian, thereby changing the signal for the pedestrian from red to blue or switching from a red signal to a green signal. Proposals have been made to use it for automatic processing, such as shortening the time until the start.

[0003]

However, in such a conventional pedestrian detection apparatus using a pedestrian sensor, an object entering a certain area for transmitting and receiving ultrasonic waves is not necessarily a pedestrian. However, there is a possibility that it may be a pedestrian passing on the sidewalk, or temporary luggage or bicycles parked. In such a case, there is a problem that the flow of vehicle traffic is unnecessarily obstructed. Therefore, an infrared sensor or the like is added to distinguish between a person and an object, a moving object is detected using the Doppler effect,
Attempts have been made to improve the accuracy of identifying traversers by applying various types of image processing and arithmetic processing.However, when the Doppler effect is used, a stationary object cannot be detected, and when other means are used. However, there was a problem that the cost was high. The present invention has been made in view of the above problems, and has as its object to provide a traverser detecting device capable of accurately distinguishing a pedestrian on a road from other pedestrians and fixed obstacles at low cost. The purpose is.

[0004]

According to a first aspect of the present invention, there is provided an ultrasonic transmitting means for transmitting an ultrasonic wave toward a certain area on a road near a pedestrian crossing, and a method for reflecting an object in the certain area. Ultrasonic wave receiving means for receiving the reflected wave, and the transmitted wave transmitted from the ultrasonic wave transmitting means, the arithmetic processing based on the reflected wave received by the ultrasonic wave receiving means,
Processing means for sensing a position of an object present in the fixed area, wherein the processing means stops the sensed object within an arbitrary area within the fixed area for a first set time or more. If there is, this is determined as a crosser and detected. According to this, ultrasonic waves are transmitted toward a certain area on the road near the pedestrian crossing by the ultrasonic transmitting means, and the ultrasonic wave receiving means receives a reflected wave hitting an object in the certain area and reflects the waves. Means for performing an arithmetic process based on the transmitted wave transmitted from the ultrasonic wave transmitting means and the reflected wave received by the ultrasonic wave receiving means to detect the position of an object existing in a certain area, and to detect the position of the object in the certain area. Is detected as a pedestrian that has stopped for more than the first set time within an arbitrary area of the vehicle, so that it can be distinguished from a pedestrian passing through a certain area. Even if the user moves a little while waiting, it is only necessary to be within an arbitrary area range, so that the crosser can be accurately determined.
According to a second aspect of the present invention, in the traversing person detection apparatus according to the first aspect, the processing unit is configured such that the sensed object is longer than the first set time within an arbitrary area within the certain area. If it has been present for more than the second set time, it has a state learning function of judging it as a fixed object and excluding it from the sensing target. According to this, when a traverser is detected by the processing means, if the sensing object continues to exist even after the second set time longer than the first set time in an arbitrary area range, the crossing is performed. It is more likely that people left luggage and bicycles instead of people,
By providing a state learning function of judging this as a fixed object and excluding it from the sensing target, it is possible to more accurately detect the crosser thereafter. According to a third aspect of the present invention, in the traverser detecting apparatus according to the second aspect, the state learning function detects an object when the processing unit receives a reflected wave of a predetermined threshold level or more. if you did this,
A method in which a constant value is added to a reflected wave level of an object that continues to exist for more than the second set time, and the threshold is set as a new threshold to detect the object. is there. According to this, when it is assumed that the object is sensed when the processing means receives a reflected wave of a predetermined threshold level or more, the reflected wave level of the object that continues to exist for more than the second set time as a state learning function Plus a constant value to
Since the object detection is performed by setting the threshold value as a new threshold value, even if an object exceeding the threshold level exists in a certain area, it is treated as an undetected object, and a new Since the detection of the incoming object is not affected, the detection accuracy of the traversing person can be further improved.

According to a fourth aspect of the present invention, in the traversing person detecting apparatus according to the second aspect, the state learning function is performed when the processing means receives a reflected wave of a predetermined threshold level or more. , The predetermined area is divided into a plurality of areas, and a threshold of an area including a reflected wave of an object that continues to exist for more than the second set time is set to a fixed value for the reflected wave. The added level is set, and a new threshold is set in accordance with the threshold to detect an object. According to this, when it is assumed that an object is detected when the processing unit receives a reflected wave of a predetermined threshold level or more, the predetermined area is divided into a plurality of areas as a state learning function, and the second setting is performed. The threshold of the area including the reflected wave of the object that continues to exist over time is set to a level obtained by adding a constant value to the reflected wave, and a new threshold is set in accordance with the threshold to perform object sensing. Since objects that exceed the threshold level exist in a certain area, they are treated as undetected objects, and do not affect the detection of objects that newly enter the area. The detection accuracy can be further improved. Claim 5
According to the invention described in (1), in the traversing person detection apparatus according to claim 3 or 4, a mode setting switch capable of arbitrarily setting a constant value to be applied to the reflected wave is provided. According to this, a mode setting switch is provided so that a constant value added to the reflected wave can be arbitrarily set.
The detection sensitivity can be appropriately adjusted according to the situation, and the detection accuracy of the traversing person can be improved. According to a sixth aspect of the present invention, in the traverser detecting apparatus according to any one of the third to fifth aspects, when an object that has been present for more than the second set time has moved, the new object is detected. This is to change the threshold value set in. According to this, when an object that has been present for more than the second set time moves, the threshold value is changed to an appropriate threshold value according to the object position, so that accurate crosser detection can always be performed. . According to a seventh aspect of the present invention, in the traversing person detecting device according to any one of the first to sixth aspects, when the processing means detects a traversing person, an output means for outputting a detection result outside the apparatus. Is further provided. According to this, since the output unit can output the detection result of the traversal by the processing unit to the outside of the apparatus, it is possible to provide various services to the traverser.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram illustrating a schematic configuration of a crosser detection device 10 according to the present embodiment. 1 includes an output unit 12 as an output unit, a processing unit 14 as a processing unit, an operation mode setting switch 16 as a mode setting switch, and an ultrasonic transmission unit as a part of the ultrasonic transmission unit. 18, an input / output transformer 20 as a part of the ultrasonic transmitting means and the ultrasonic receiving means, an ultrasonic transmitter / receiver 22 as a part of the ultrasonic transmitting means and the ultrasonic receiving means, and a part of the ultrasonic receiving means It is composed of an ultrasonic receiving unit 24 and the like. The output unit 12 outputs, to the outside of the device, a detection signal detected and detected by the processing unit 14 described later as a traverser. As an external device that outputs a detection signal, for example, there is a voice guidance device for traversers, and voice guidance such as "Please wait for a while" can be provided to traversers waiting for signals. In addition, as an external device, there is a control device of a traffic light, etc., and it is possible to change a traffic light for a pedestrian from red to blue, shorten a lighting time of red, and provide convenience to a pedestrian. . The processing unit 14 includes an MPU (micro processing unit), a CPU (central processing unit), and the like. The processing unit 14 controls the entire apparatus, and performs transmission and reception processing of ultrasonic waves and transmission and reception signals of ultrasonic waves. Performs arithmetic processing to detect the position of the object, sets the threshold for detecting the object, divides the sensing area, sets the area range, uses a timer to understand the time the object exists, A judgment process for determining whether or not the object is a crosser by comprehensively judging the sensing result is performed. Further, the processing unit 14 also has a state learning function of removing a fixed object (a fixed obstacle or the like) from the sensed object. The operation mode setting switch 16 allows the setting value to be added to the received reflected wave level to be arbitrarily set according to the situation in order to operate the state learning function in the processing unit 14 described above. The ultrasonic transmission unit 18 performs an ultrasonic transmission process based on a control signal from the processing unit 14. The input / output transformer 20 converts an output signal from the ultrasonic transmission unit 18 and sends the output signal to an ultrasonic transmitter / receiver 22 described later, and converts the ultrasonic wave received by the ultrasonic transmitter / receiver 22 into an input signal to convert the ultrasonic signal into an input signal. This is sent to the receiving unit 24. The ultrasonic transmitter / receiver 22 transmits an ultrasonic wave toward a certain area, and receives a reflected wave reflected by an object in the certain area. The ultrasonic wave receiving section 24 converts the reflected wave received by the ultrasonic wave transmitter / receiver 22 into an input signal by the input / output transformer 20, and receives this signal.

FIG. 2 shows a crosswalk 3 in this embodiment.
FIG. 3 is a plan view illustrating a state of sensing an object by a traversing person detection device 10 installed on a sidewalk 30 that is in contact with 2. The pedestrian detection device 10 shown in FIG. 1 is installed at a fixed height above the ground so as not to hinder pedestrians and the like, and the area around the sidewalk 30 in contact with the pedestrian crossing 32 is a sensing area (indicated by a broken line and hatching in FIG. 2). (The indicated area) 34.
On the sidewalk 30, there are pedestrians 38 who stop as a pedestrian from the sidewalk 30 to cross the pedestrian crossing 32, pedestrians 36 coming and going along the sidewalk 30, and obstacles such as standing trees placed on the sidewalk 30. Alternatively, a fixed object 40 indicating a bicycle, luggage, or the like temporarily placed on the road is shown. It is assumed that a traffic signal for a pedestrian 38 is installed on the pedestrian crossing 32. It should be noted that the white arrows shown on the pedestrian 36 and the crosser 38 in FIG. 2 indicate the respective traveling directions and movements. FIG. 3A is a diagram illustrating a transmitted wave of an ultrasonic wave transmitted from the traversing person detection device 10 illustrated in FIG. 2, and FIGS. 3B to 3E are diagrams illustrating the pedestrians illustrated in FIG. 2. FIG. 7 is a diagram showing a time lapse of a reflected wave reflected from a light source 36. FIG. 4A shows the crosser detection device 1 shown in FIG.
It is a figure which shows the reflected wave from the traverser 38 received at 0, and FIG. 6 (b) is a figure explaining the traversing person detection operation based on the reflected wave of (a). 3 and 4 show:
At the same timing as the transmitted wave, a similar waveform appears in the received reflected wave, which is a waveform in which the transmitted wave and the reverberant wave are superimposed, and is not used for sensing an object.

Hereinafter, the operation of detecting a traversal according to the present embodiment will be described. FIG. 5 is a flowchart illustrating a crosser detection operation. First, when the processing for detecting a traversal is started in the processing unit 14 of the traversing person detection device 10 in FIG. 1, the processing unit 14 controls the ultrasonic transmission unit 18,
Ultrasonic waves are transmitted into the sensing area 34 via the input / output transformer 20 and the ultrasonic transceiver 22. Then, the transmitted ultrasonic wave is reflected by hitting an object in the sensing area 34, and the reflected wave is received by the ultrasonic transmitter / receiver 22, and the input / output transformer 2
0 is received by the ultrasonic receiver 24. Processing unit 14
Then, by performing arithmetic processing based on the time difference between the transmitted wave and the received wave, it is possible to detect at which position in the sensing area 34 an object is present (step S100). If there is an object in the area 34, the process proceeds to step S102, and it is determined whether or not the object is stopped within a certain range of area. In the present embodiment, as shown in FIG. 3, the sensing area 34 (having a length of 6 m) is divided into a plurality of areas such as a, b, c, d, e,. The position of the object in the divided area, which is moving or stopped, and the range of the area if the object is moving are grasped. Here, the sensing area 34
If the long direction is 6 m, as shown in FIG. 4, the divided area is divided into 12 equal parts, resulting in 0.5 m per area and a time difference of about 0.6 ms.

In this embodiment, as a condition for recognizing that the sensing object is stopped, it is conceivable that a part of the object is located on the boundary of the divided area. Therefore, as shown in FIG. An auxiliary area is defined as an area including one area before and after the area which is the presence detection position of the object. If the presence of the object is detected in this auxiliary area for a predetermined time (here, 2 seconds), the object is stopped. Shall be. This stationary object needs to be recognized because the pedestrian is considered to be a person standing in front of the pedestrian crossing (due to the red traffic light). The above constants are merely examples, and the number of divisions of the area, the range of the auxiliary area, and the like can be set to any value according to the situation. In addition, if the object moves to the position A or the position B in FIG. 4 within 2 seconds after the presence of the object is detected, the above condition is not satisfied, and therefore, it is recognized that the sensing object has not stopped. In step S102, when it is recognized that the sensing object has stopped, and the process proceeds to step S104, and the object continues to exist in the same state for 5 minutes, the possibility of waiting for the signal of the pedestrian decreases, It is considered to be equivalent to temporarily placing luggage or bicycles. Then, the traversing person detection device 10 of the present embodiment has a state learning function of recognizing the object as an obstacle (or a fixed object) or the like and removing the object so as not to be sensed as an object thereafter. This state learning function will be described later in detail. In step S104, if the stopped object moves within 5 minutes, it does not recognize this as an obstacle (or a fixed object), but recognizes it as a traversal that is a sensing target, and performs target sensing processing. (Step S106). In the target sensing process, when a traverser is detected by the processing unit 14, a detection signal of the traverser is output to the outside of the apparatus via the output unit 12. When a traverser's detection signal is output to a traverser's voice guidance device, etc., voice guidance such as "Please wait" is automatically given to traversers waiting for the signal without pressing any buttons. Can be. Also, if the detection signal of the pedestrian is output to the control device of the traffic light, etc., the traffic light for the pedestrian is changed from red to blue, the lighting time of red is shortened, and the convenience to the pedestrian is achieved. It becomes possible.

Next, the state learning function performed in the processing unit 14 will be described. FIG. 6A is a diagram showing a received wave in a state where there is no sensing object in the sensing area (normal time), and FIG. 6B shows a case where the sensing object continues to exist in the same state for 5 minutes or more. FIG. 3C is a diagram illustrating a received wave including a reflected wave of a fixed obstacle, and FIG. 3C is a diagram illustrating a state in which a new sensing threshold is formed based on the reflected wave of FIG. FIG. 7D is a diagram showing a state in which a new sensing threshold value is formed for each divided area based on the reflected wave in FIG. 7B. FIG. 7 is a flowchart for explaining an example of the state learning operation. It is. First, as shown in FIG. 7, when starting the traversing person detection operation, whether or not to perform state learning is selected (step S200). When performing the state learning, the processing unit 14 acquires the AD value of the ultrasonic wave reception (step S2).
02). At this time, as shown in FIG.
, A detection threshold value raised by a certain level from the reception wave level is set, and the object is detected only when the reflected wave level exceeds the detection threshold value. This is to prevent a small object or a received wave from being erroneously detected as a target object even when noise is present. Thus, if the object exceeds the sensing threshold value of FIG. 6B and is stopped for two seconds or more, it is determined whether or not the object is an obstacle (see step S104 of FIG. 5). Here, if the sensing object has been present in the same state for more than 5 minutes, it is determined as a fixed obstacle, and a sensing threshold value according to learning mode 1 as shown in FIG. 6C is formed. That is, FIG.
A new sensing threshold is obtained by adding the value set by the operation mode setting switch 16 to the sensing threshold of (b) and the reflected wave of the fixed obstacle. In this case, as shown in FIG. 6 (c), a sensing threshold value is set in which a fixed value is added to the reflected wave that is a fixed obstacle, so that the sensitivity of sensing an object in another area is set. Can be prevented from being detected without changing the fixed obstacle. For this reason, it is possible to ignore the reflected wave of the object that has been determined as the fixed obstacle, and it is possible to reliably and accurately grasp only the movement of another object. Further, the learning mode 1 shown in FIG.
In the case of, when the fixed obstacle moves, the sensing threshold obtained by adding the value set by the operation mode setting switch 16 to the reflected wave is canceled, and when the fixed obstacle is determined,
A new sensing threshold similar to the above is created.

If the object exceeds the sensing threshold shown in FIG. 6 (b), it is stopped for more than 2 seconds, and if the sensed object remains in the same state for more than 5 minutes, , A fixed obstacle, but in FIG.
It is also possible to form a sensing threshold such as That is, as shown in FIG. 6D, the sensing area is divided into a plurality of areas, and the change of the sensing threshold is performed for each divided area. In this case, if there is a divided area in which the reflected wave of the object regarded as the fixed obstacle exceeds the normal sensing threshold (see FIG. 6B), the counter is incremented (step S206), and the sensing is performed. If the threshold has not been exceeded, the counter is decremented (step S208). This counter is provided for each divided area, and it is determined whether or not to update the threshold according to the value of the counter (step S210). The increment number and decrement number of the counter are, here, constants of a ROM (not shown) incorporated in the processing unit 14, and can be set so as to change the up and down values.
If the threshold value is not updated, the previous threshold value is maintained (step S220), and the process returns to the start and the above-described processing is sequentially repeated. When the threshold value is updated, it is determined whether or not learning is performed in a direction to increase the threshold value (step S212). In the case of YES, the threshold value is updated in a direction to increase the threshold value (step S214). In the case of, the threshold value is updated in a lowering direction (step S218).
As described above, when the threshold value is updated, the counter of the updated area is reset (step S21).
6) Returning to the start, the above processing is sequentially repeated.
In the case of performing the state learning as described above, a new sensing threshold is obtained by adding a value set by the operation mode setting switch 16 to a normal sensing threshold value and a reflected wave of an object which is a fixed obstacle. Value (in the case of learning mode 1),
The detection threshold can be changed for each divided area, and the counter of each divided area is incremented or decremented depending on whether it is above or below the previous detection threshold, and the counter value becomes a constant value Then, the sensing threshold value is changed for each divided area (in the case of the learning mode 2). When such state learning is performed,
In accordance with the movement of the object which is always present in the sensing area, the fixed obstacle is not detected, and the movement of other objects can be grasped accurately and reliably.

[0012]

As described above, according to the first aspect of the present invention, it is possible to accurately and easily distinguish between a pedestrian and a pedestrian who passes through a certain area. Even if the waiting traverser moves a little, the traverser can be accurately detected because it may be within an arbitrary area range. According to the invention described in claim 2, when the sensing object continues to exist within the arbitrary area range even after the second set time longer than the first set time, it is not a crosser, Since a state learning function of judging the object as a fixed object and excluding it from the sensing target is provided, the subsequent crosser detection can be performed more accurately. According to the third and fourth aspects of the present invention, a fixed object exceeding a threshold level is treated as an undetected object even if it is present in a certain area, and is used to detect an object newly entering the area. Since it has no influence, the detection accuracy of the traverser can be further improved. According to the fifth aspect of the present invention, the mode setting switch is provided so that the constant value added to the reflected wave can be set arbitrarily, so that the detection sensitivity can be appropriately adjusted according to the situation. Detection accuracy can be improved. According to the invention described in claim 6, when a fixed object that has been present for more than the second set time moves, the threshold value is changed to an appropriate threshold value in accordance with the position of the object. Person detection can be performed. According to the invention described in claim 7, since the output unit can output the detection result of the traverser by the processing unit to the outside of the apparatus, it is possible to provide various services to the traverser.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a crosser detection device according to the present embodiment.

FIG. 2 is a plan view illustrating a state in which an object is detected by a pedestrian detection device installed on a sidewalk in contact with a pedestrian crossing in the present embodiment.

3A is a diagram showing a transmission wave of an ultrasonic wave transmitted from the traversing person detection device shown in FIG. 2, and FIGS.
(E) is a figure which shows the time course of the reflected wave reflected from the passerby shown in FIG.

FIG. 4A is a diagram showing a reflected wave from a traverser received by the traverser detecting apparatus shown in FIG. 2, and FIG.
It is a figure explaining the traversing person detection operation based on a reflected wave of (a).

FIG. 5 is a flowchart illustrating an operation of detecting a crosser.

FIG. 6A is a diagram illustrating a received wave in a state where no sensing object is present in a sensing area, and FIG. 6B is a diagram illustrating a fixed obstacle in which the sensing object continues to exist in the same state for 5 minutes or more. FIG. 3C is a diagram showing a received wave including the reflected wave of FIG. 3C, FIG. 3C is a diagram showing a state where a new sensing threshold is formed based on the reflected wave of FIG. 3B, and FIG. It is a figure which shows the state which formed the new sensing threshold value of divided area unit based on the reflected wave of b).

FIG. 7 is a flowchart illustrating an example of a state learning operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Crosser detection device, 12 output part, 14 processing part, 16 operation mode setting switch, 18 ultrasonic transmission part, 20 input / output transformer, 22 ultrasonic transmitter / receiver, 24 ultrasonic reception part, 30 sidewalk, 32 pedestrian crossing, 34 sensing area, 36 pedestrian, 38 pedestrian, 40 fixed object, 42 traffic light.

Claims (7)

[Claims] 1. An ultrasonic transmitting means for transmitting an ultrasonic wave toward a certain area on a road near a pedestrian crossing; an ultrasonic receiving means for receiving a reflected wave reflected by an object in the certain area; Processing means for performing arithmetic processing based on the transmitted wave transmitted from the ultrasonic wave transmitting means and the reflected wave received by the ultrasonic wave receiving means, and sensing an object position existing in the predetermined area. The processing means determines that the detected object is a crosser when the detected object is stopped within an arbitrary area within the predetermined area for more than a first set time. Crosser detection device. 2. The processing unit according to claim 1, wherein the detected object continues to exist in an arbitrary area within the predetermined area for a second set time longer than the first set time. The traverser detecting apparatus according to claim 1, further comprising a state learning function of judging the object as a fixed object and excluding the object from the sensing target. 3. If the processing means detects an object when a reflected wave of a predetermined threshold level or more is received by the processing means, the object continues to exist for more than the second set time. 3. The traversing person detecting apparatus according to claim 2, wherein a value obtained by adding a constant value to the reflected wave level of the target object and the threshold value are set as a new threshold value so as to detect an object. . 4. The state learning function according to claim 1, wherein when the processing means receives a reflected wave of a predetermined threshold level or more, the state learning function detects the object and divides the predetermined area into a plurality of areas. The threshold value of the area including the reflected wave of the object that continues to exist for more than the second set time is set to a level obtained by adding a constant value to the reflected wave, and a new threshold value is set in accordance with the threshold value. 3. The traversing person detecting device according to claim 2, wherein the object is detected by detecting the object. 5. The traverser detecting apparatus according to claim 3, further comprising a mode setting switch capable of arbitrarily setting a constant value applied to the reflected wave. 6. The apparatus according to claim 3, wherein, when an object that has been present for more than the second set time moves, the newly set threshold value is changed. The traverser detection device according to the paragraph. 7. The apparatus according to claim 1, further comprising output means for outputting a detection result to the outside of the apparatus when the processing means detects a traverser. Crosser detection device.