JPH0714941Y2 - Inter-vehicle distance alarm device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The first and second inventions relate to an inter-vehicle distance warning device which measures an inter-vehicle distance and gives an alarm to a driver or the like.

[Prior Art] Usually, when a vehicle travels on a relatively vacant road, the driver keeps a sufficient inter-vehicle distance and pays sufficient attention to the surroundings.

However, in recent years, as the number of vehicles has increased, rush conditions have been increasing in urban areas during commuting hours in the morning and evening and in suburbs on holidays. In such a rush state, each vehicle is traveling at a low speed and continuously, and the inter-vehicle distance of each vehicle is so short that another vehicle cannot interrupt it. In addition, it runs at extremely low speed, each vehicle stops for a long time due to traffic lights at intersections, natural traffic, etc., or if the distance between vehicles is short, it will be shortened immediately or the lane will be changed, These actions are often repeated, such as running at extremely low speed again. As a result, the stress on the driver increases, and if the same driving condition continues, such as when the driver stays in the high-stress state for a long time in a row of traffic jams, the driver's attention to the surroundings becomes distracting. Therefore, in such a situation, since the speed of each vehicle is relatively low, it does not lead to a serious accident causing casualties, but contact accidents between vehicles tend to increase.

Therefore, as a method for overcoming the above situation, the following inter-vehicle distance warning device has been devised, which measures the inter-vehicle distance of a famous vehicle and gives an alarm to a driver or the like.

FIG. 11 is a block diagram showing a first configuration example of a conventional inter-vehicle distance warning device, 1 is a sensor for transmitting and receiving ultrasonic waves and the like, 2 is an inter-vehicle distance from a vehicle in front using an output signal of the sensor 1. A discriminator 3 which measures a distance and compares the inter-vehicle distance with a predetermined distance set in advance to output a binary discrimination signal is an alarm device which issues an alarm using the discrimination signal. Also,
FIG. 12 is an example in which the inter-vehicle distance warning device of FIG. 11 is mounted on an actual vehicle, 4 is a vehicle equipped with the inter-vehicle distance warning device, and 5 is a front vehicle.

In such a configuration, first, the discriminator 2 radiates ultrasonic waves and the like using the sensor 1. As a result, this ultrasonic wave is reflected by the vehicle 5 and becomes a reflected wave signal and is input to the sensor 1 again. Next, the discriminator 2 measures the inter-vehicle distance Sx between the vehicle 4 and the vehicle 5 based on the propagation time of the ultrasonic signal and the like. Further, the discriminator 2 performs the following operation using this inter-vehicle distance Sx. Next, the operation of the discriminator 2 will be described based on the flowchart of FIG. When the inter-vehicle distance Sx is measured, the discriminator 2 first proceeds to the process of step S1 and determines whether the inter-vehicle distance Sx is shorter than a predetermined distance So set in advance. If the result of this determination is "YES", as shown in FIG. 14 (a), an "L" level determination signal is generated and then the operation proceeds to step S2. In step S2,
As shown in FIG. 14 (b), after the alarm is generated by using the alarm device 3 at the rise of this discrimination signal, the step S1
Return to. On the other hand, if the result of the determination in step S1 is "NO", as shown in FIG. 14 (a), an "H" level determination signal is generated and then the process proceeds to step S3. In step S3, as shown in FIG. 14 (b), an alarm is generated using the alarm device 3 by the rise of this determination signal, and then the process returns to step S1.

Since this inter-vehicle distance warning device operates in this way, for example, the driver of the vehicle 4 inadvertently exceeded the predetermined distance So and placed the vehicle 4 near the vehicle 5 while the vehicle 5 was running at a low speed or stopped. In this case (hereinafter, this state is referred to as a proximity state), the discriminator 2 issues an alarm using the alarm device 3 (hereinafter, this alert is referred to as a proximity alarm). As a result, the driver of the vehicle 4 recognizes that the inter-vehicle distance Sx has become shorter than the predetermined distance So and slows down the traveling speed of the vehicle 4 or stops the vehicle 4. Therefore, the collision between the vehicle 4 and the vehicle 5 can be prevented.

In addition, when the vehicle 4 is stopped behind the vehicle 5 by a predetermined distance So due to a traffic light at an intersection or the like, and the vehicle 5 starts because the traffic light changes from red to blue, If the driver does not notice it while looking at the map or the like, the discriminator 2 issues an alarm using the alarm device 3 (hereinafter, this alarm is referred to as an isolation alarm). As a result, the driver of the vehicle 4 recognizes that the inter-vehicle distance Sx has become longer than the predetermined distance So (hereinafter, this state is referred to as an isolated state) and starts the vehicle 4. Therefore, the flow of the vehicle becomes smooth. .

The above-mentioned conventional example is a warning for a driver of a vehicle equipped with an inter-vehicle distance warning device. Next, a conventional example of a warning for a driver of a following vehicle will be described. FIG. 15 is a block diagram showing a second configuration example of a conventional inter-vehicle distance warning device. In this figure, parts corresponding to the respective parts in FIG. 11 are assigned the same reference numerals and explanations thereof are omitted. . In the inter-vehicle distance warning device shown in this figure, a warning lamp 6 is provided in place of the warning device 3 shown in FIG. Further, FIG. 16 is an example of mounting the inter-vehicle distance warning device of FIG. 15 on an actual vehicle,
In this figure, parts corresponding to the parts in FIG. 12 are assigned the same reference numerals and explanations thereof are omitted. In this figure,
Reference numeral 7 is a following vehicle, and reference numerals 8 and 9 are a brake lamp and a high mount stop lamp which are turned on when a brake is depressed or a side brake is applied.

Normally, as a means to prevent a rear-end collision with the following vehicle,
As shown in FIG. 16, a method is known in which a brake lamp 8 and a high mound stop lamp 9 are turned on to inform a succeeding vehicle 7 of deceleration or stop of the vehicle 4.

Further, there is a method of mounting the inter-vehicle distance warning device shown in FIG. 15 on the vehicle 4 to warn the following vehicle 7. The operation will be described below. First, the discriminator 2 radiates ultrasonic waves and the like using the sensor 1. As a result, this ultrasonic wave or the like is reflected by the vehicle 5 and becomes a reflected wave signal and is input to the sensor 1 again. Next, the discriminator 2 measures the inter-vehicle distance Sx between the vehicle 4 and the vehicle 5 based on the propagation time of the ultrasonic signal and the like. Further, the discriminator 2 performs the following operation using this inter-vehicle distance Sx. Next, the operation of the discriminator 2 will be described based on the flowchart of FIG. When the inter-vehicle distance Sx is measured, the discriminator 2 first proceeds to the process of step S1 and determines whether the inter-vehicle distance Sx is shorter than a predetermined distance So set in advance. If the result of this determination is "YES", as shown in FIG. 18 (a), an "L" level determination signal is generated and then the operation proceeds to step S2. In step S2,
As shown in FIG. 18 (b), after the warning light 6 is turned on by the fall of the determination signal, the process returns to step S1. On the other hand, if the result of the determination in step S1 is "NO", as shown in FIG. 18 (a), a "H" level determination signal is generated and then the process proceeds to step S3. In step S3, FIG. 18 (b)
As shown in FIG. 5, after the warning light 6 is turned off by the rise of the determination signal, the process returns to step S1.

Since the inter-vehicle distance warning device operates in this manner, for example, when the driver of the vehicle 4 inadvertently brings the vehicle 4 and the vehicle 5 into the close state while the vehicle 5 is traveling at a low speed or is stopped, The proximity lamp is given to the vehicle 7 regardless of whether the driver of the vehicle 4 depresses the brake when the warning light 6 is turned on. As a result, the driver of the vehicle 7 is alerted before the vehicle 4 is decelerated, and the traveling speed of the vehicle 7 is slowed or the vehicle 7 is stopped. Therefore, a collision between the vehicle 4 and the vehicle 7 can be prevented.

Further, the warning light 6 of this device is turned on when the vehicle 4 and the vehicle 5 are in the proximity state, and as shown in FIG. When and were in the isolated state, the lamps and characters were turned off.

[Problems to be solved by the invention] By the way, when the driving operation such as running or stopping is repeated even in the rush state, there is a change in the driving operation.
Despite the stress, the driver pays a lot of attention to the surroundings. Nevertheless, the conventional vehicle-to-vehicle distance warning device described above is irrelevant to the driver's mental state regardless of the vehicle 4 and vehicle 5.
Since the alarm device 3 or the alarm light 6 is activated each time when and are in the proximity state or in the isolation state,
The drivers of vehicles 4 and 7 may find it annoying. Especially, in the case of the alarm device 3, sound is generated, which is even more annoying.

In other words, even if the driver is relatively paying attention to the surroundings even in a rush state, it is not necessary to give an alarm to each driver. May induce distraction. Therefore, the driver of the vehicles 4 and 7 ignores these warnings, or turns off the power supply of this device due to the annoyance, and the driver in the distracted mental state of the device aims at this device. There was a problem that the warning did not work.

The first and second inventions are made under such a background, and do not work when the driver pays attention to the surroundings, and do not work in the driver's distracted mental state. An object of the present invention is to provide an inter-vehicle distance warning device that operates effectively.

[Means for Solving the Problems] In the first invention, the inter-vehicle distance to a vehicle ahead is measured, the inter-vehicle distance is compared with a preset predetermined distance, and the inter-vehicle distance is less than the predetermined distance. If the distance is shorter, the value becomes the first value. If the inter-vehicle distance is longer than the predetermined distance, the value becomes the second value.
Discriminating means for outputting a discriminating signal having a value of, a first detecting means for detecting a change from the first value to the second value of the discriminating signal and outputting a first signal, and the discriminating signal. Of the second signal from the second value to the first value and outputs a second signal;
First time measuring means for measuring a predetermined period of time, second time measuring means for measuring a second predetermined period from the time when the second signal is generated, and the second signal is generated after the lapse of the first predetermined period. And an alarm generating means for generating an alarm in at least one of the case where the first signal is generated after the lapse of the second predetermined period and the case where the first signal is generated.

Further, according to the second invention, the inter-vehicle distance to a vehicle ahead is measured, and the inter-vehicle distance is compared with a predetermined distance set in advance, and when the inter-vehicle distance is shorter than the predetermined distance, the first value is obtained. Therefore, when the inter-vehicle distance is longer than the predetermined distance, a discriminating means for outputting a discriminating signal having a second value, and a first detecting the change from the first value to the second value of the discriminating signal,
The first detection means for outputting the signal, the second detection means for detecting the change of the discrimination signal from the second value to the first value, and outputting the second signal, and the first detection means. The present invention is characterized by further comprising: a clocking means for timing a predetermined period after the signal is generated, and a warning generating means for giving a warning to a driver of the following vehicle when the second signal is generated after the lapse of the predetermined period.

[Operation] According to the first aspect of the invention, first, the inter-vehicle distance between the vehicle in front and the vehicle on which this device is mounted is measured. The current inter-vehicle distance is shorter than the predetermined distance and the inter-vehicle distance so far is longer than the predetermined distance after the first predetermined time or more, and the current inter-vehicle distance is longer than the predetermined distance. In addition, since an alarm is issued in at least one of the situation that the inter-vehicle distance till then is shorter than the predetermined distance and the second predetermined time or more has elapsed, the driver of the vehicle equipped with this device is It is possible to recognize the state of proximity and / or isolation from the vehicle in front of the vehicle.

According to the second aspect of the invention, first, the inter-vehicle distance between the vehicle in front and the vehicle on which the device is mounted is measured.
The current inter-vehicle distance is shorter than the predetermined distance, and
The driver of the following vehicle will be alerted to the driver of the following vehicle in the situation where the inter-vehicle distance up to that point is longer than the prescribed distance for a prescribed time or more. Can recognize the proximity.

[Examples] Before describing the examples, the relationship between the running condition of the vehicle and the mental state of the driver will be touched upon. First, FIG. 8 is a diagram showing the running condition of the vehicle with the passage of time. When the vehicle 4 and the vehicle 5 are in the isolated state, the “H” level is set, and in the close state, the “L” level is set. There is. Incidentally, one scale is 2 seconds.

In this figure, (a) shows that each vehicle is traveling relatively smoothly and the inter-vehicle distance is sufficient. (B) is in a rush state, so each vehicle is traveling at a low speed, and is in a close state, and if the inter-vehicle distance increases even a little, the inter-vehicle distance can be shortened immediately so as not to be interrupted by another vehicle. , It also shows the situation where the speed is repeatedly reduced and accelerated. In (c), at first, the vehicles 4 and 5 were traveling with a sufficient inter-vehicle distance, but the vehicle 5 was decelerated or stopped due to a signal such as a natural traffic jam or an intersection. After decelerating or stopping in close proximity, after traveling or stopping at a low speed for a long time,
The vehicle 5 is accelerated or departed because the natural traffic is eliminated or the traffic signal is changed, and then the vehicle 4 is accelerated or departed after a sufficient distance between the vehicle 5 and the vehicle 5 is obtained.

Further, in (d), at first, the vehicles 4 and 5 were traveling with a sufficient inter-vehicle distance, but since the vehicle 5 stopped due to a temporary stop or the like, the vehicle 4 stopped close to the vehicle 5, The situation is shown in which the vehicle 5 starts immediately, and then the vehicle 4 starts after a sufficient distance between the vehicle 5 and the vehicle 5. In (e), at first, the vehicles 4 and 5 were traveling with a sufficient inter-vehicle distance, but since the vehicle 5 stopped due to a temporary stop or the like, the vehicle 4 stopped close to the vehicle 5 and immediately after that. The vehicle 5 departs from the vehicle and is in an isolated state, and after a while, the vehicle 4 has departed and is brought into a close state again, and then the vehicle 4 moves to a traveling state with a sufficient inter-vehicle distance, or , The vehicle 5 started immediately after being stopped as described above and became in an isolated state, but stopped again, and after a while, the vehicle 4 started and stopped in close proximity, and then the vehicle 5 immediately started. After that, the situation is shown in which the vehicle 4 starts with a sufficient distance between the vehicle 4 and the vehicle 5. In (f), at first, the vehicles 4 and 5 were traveling with a sufficient inter-vehicle distance, but the vehicle 5 was decelerated or stopped due to a signal such as a natural traffic jam or an intersection. After decelerating or stopping in close proximity, after running or stopping at a low speed for a long time, the vehicle 5 accelerates or departs because the natural traffic congestion is resolved or the signal has changed, and the vehicle 4 becomes isolated. The figure shows a situation in which the vehicle 4 has approached due to departure and then the vehicle 4 has started to travel with a sufficient distance between the vehicle 4 and the vehicle 5.

Further, in (g), the vehicle 4 is stopped in the vicinity of the vehicle 5 in which the vehicle 4 is stopped, and the vehicle 5 immediately starts to enter an isolated state, but is stopped again, and after a while, the vehicle 4 starts and approaches the vehicle 5. Then, the vehicle 5 is started again after a long stop, and then the vehicle 4 is started with a sufficient distance between the vehicle 5 and the vehicle 5. In (h), the vehicle 4 stops in the vicinity of the stopped vehicle 5, and the vehicle 5 immediately starts to enter the isolated state, but stops again, and after a while, the vehicle 4 starts and approaches and again. After stopping for a long time, the vehicle 5 departs and is in an isolated state, and after a while, the vehicle 4 has departed and approaches again. Then, the vehicle 4 starts to travel with a sufficient distance from the vehicle 5. It shows the situation. In (i), at first, the vehicles 4 and 5 were traveling with a sufficient inter-vehicle distance, but since the vehicle 5 stopped due to a temporary stop or the like, the vehicle 4 stopped close to the vehicle 5 and the vehicle 5 Immediately started and was in an isolated state, but stopped again, and after a while, vehicle 4 started and stopped again in close proximity, then vehicle 5 immediately started and became an isolated state, and after a while, vehicle 4 The figure shows a situation in which the vehicle 4 has approached due to departure and then the vehicle 4 has started to travel with a sufficient distance between the vehicle 4 and the vehicle 5.

In reality, the traveling pattern is more complicated than that in the above case, but only typical patterns are shown here.

Next, I will touch on the mental state of the driver. As shown in FIG. 8 (a), when the vehicle 5 is traveling with a sufficient vehicle-to-vehicle distance, and FIG. 8 (b), (d), (e)
As shown in (i) and (i), when the inter-vehicle distance to the vehicle 5 changes in a short time, that is, when there is a change in driving operation such as repeated acceleration and deceleration of speed or starting immediately after stopping. Drivers tend to always pay attention to their surroundings.

However, FIG. 8 (c), (f), (g) and (h)
As shown in, when there is no change in driving operation for a long time such as traveling at a low speed for a long time or stopping while staying close to the vehicle 5, the traveling speed is low and the visibility is small, so that the driver's attention tends to be most distracted. It is in. That is, in general, human beings tend to seek change when they are left in the same environment for 3 seconds or more, and start talking to passengers in the passenger seat or starting to look at maps etc. Attention tends to be distracted.

Therefore, it is necessary to call attention to the driver in the above situation. The following two conditions can be considered as the conditions for calling attention to this driver.

First, the vehicles 4 and 5 were traveling with a sufficient inter-vehicle distance, but the vehicle 4 stopped close to the vehicle 5 because the vehicle 5 stopped due to a signal such as a natural traffic jam or an intersection. In such a situation, when waiting for a signal at an intersection or the like, each vehicle stops for a maximum of 50 seconds without moving once. However, in the case of natural congestion, the inter-vehicle distance in front of the vehicle 5 becomes large, the vehicle 5 immediately starts, and the vehicle 4 starts following this and the inter-vehicle distance with the vehicle 5 needs to be reduced again. Therefore, it is necessary to inform the driver of the vehicle 4 of the isolated state. In this case, as described above, first the vehicle 4
If the vehicle enters the isolated state within 3 seconds after stopping near the vehicle 5, the driver of the vehicle 4 is paying attention to the vehicle 5, so it is not necessary to notify the isolated state. If the vehicle enters the isolated state after a lapse of time, it is necessary to inform the driver of the vehicle 4 of the isolated state.

Therefore, when the vehicle 4 and the vehicle 5 enter the isolated state after 4 seconds or more have passed since the vehicle 4 and the vehicle 5 were in the close state, the driver of the vehicle 4 is notified of the isolated state. This is set as a condition for a quarantine alarm (see FIG. 9 (a)). Further, as shown in FIG. 9 (b), in a situation where the vehicle 4 and the vehicle 5 repeat the proximity state and the isolation state within 4 seconds, the isolation state is warned 4 seconds after the last proximity state. By doing so, a warning can be given to the driver of the vehicle 4 so as not to be distracted.

Next, when the vehicle 5 and the vehicle 4 are first stopped close to each other and the vehicle 5 starts, and then the vehicle 4 starts with a sufficient distance between the vehicle 5 and the vehicle 5, FIG. As shown in a), the vehicle 5 does not come into a close state for a long time until the vehicle 5 stops again and the vehicle 4 follows it and comes close to the vehicle 5 to stop. However, as shown in FIG. 10 (b), the vehicle 5 and the vehicle 4 are first stopped close to each other, and after the vehicle 5 has started, the vehicle 4 has a sufficient inter-vehicle distance. However, in a situation where the vehicle 4 accelerates faster than the vehicle 5 and approaches the vehicle 5 immediately after that, and then the vehicle adjusts the speed and travels in a separated state from the vehicle 5, first, the vehicle 4 starts The warning of proximity and isolation is not so important because the driver is paying attention to the front until the adjustment, but the driver of the vehicle 4 feels relieved if the vehicle 5 starts to drive in the isolated state after adjusting the speed. In this situation, when the vehicle 4 and the vehicle 5 are again in the proximity state, it is necessary to notify the driver of the vehicle 4 of the proximity state. At the intersection, when the vehicle 5 departs by following the vehicle 5 by turning right or left, the same approach or isolation state as in FIG. 10 (b) may occur. Even in such a situation, when the vehicle 4 and the vehicle 5 are in the close state again, it is necessary to notify the driver of the vehicle 4 of the close state. By the way, in the above-mentioned situation, the time from when the vehicle 4 starts traveling in the isolated state with the vehicle 5 until the driver of the vehicle 4 is relieved is longer than in the case of the isolation alarm described above.

Therefore, when the vehicle 4 and the vehicle 5 are in the isolated state and 8 seconds or more has elapsed and the vehicle 4 and the vehicle 5 are in the close state again, the driver of the vehicle 4 is informed of the close state. I will let you know. This is the condition for the proximity alarm (see Fig. 10 (a)). Further, as shown in FIG. 10 (b), in a situation where the vehicle 4 and the vehicle 5 repeat the proximity state and the isolation state within 8 seconds, the proximity state 8 seconds after the last isolation state is warned. By doing so, a warning can be given to the driver of the vehicle 4 so as not to be distracted.

By the way, since the vehicle following the vehicle 4 is traveling following the above-described traveling of the vehicle 4, the mental state regarding the driving of the driver of the following vehicle is substantially the same as the mental state regarding the driving of the driver of the vehicle 4. It is believed that there is. Therefore,
Means for giving an auxiliary warning to the driver of the following vehicle other than the brake lamp may be operated in conjunction with the operation of the above-mentioned warning given to the driver of the vehicle 4. However, if a warning is given to the driver of the following vehicle only when the vehicle 4 and the vehicle 5 are close to each other, a rear-end collision between the vehicle 4 and the following vehicle can be prevented. The reason for this is that if too much information is provided to the following vehicle, it will be rather annoying, and the driver of the following vehicle will not show a proper reaction at an important time.

An embodiment of the first and second inventions will be described below with reference to the drawings. FIG. 1 is a block diagram showing the structure of an inter-vehicle distance warning device according to an embodiment of the first invention. In this figure, parts corresponding to the parts in FIG. Is omitted. The inter-vehicle distance warning device shown in this figure differs from that shown in FIG. 11 in that a warning signal generator 10 is newly provided between the discriminator 2 and the warning device 3. Further, in the alarm signal generator 10, 11
Is an edge detection circuit that detects the rising edge of the discrimination signal, 12
Is an edge detection circuit that detects the falling edge of the discrimination signal, 13
Is an 8-second timer that outputs a pulse for 8 seconds after the output of the edge detection circuit 11 generates a pulse, and 14 is an edge detection circuit
4-second timer that outputs pulses for 4 seconds after the generation of 12 output pulses, 15 is edge detection circuit 11, 12, 8-second timer 1
Alarm device 3 by processing the output signal of 3 and 4 second timer 14
Is a logic circuit for operating.

Further, FIG. 2 is an example of a part of the concrete circuit diagram of FIG. 1, in which 16 is an output transistor of the discriminator 2 whose emitter is grounded, 17 is an output terminal for outputting a discrimination signal, 18 is an input terminal where the discrimination signal is input, 19 is an input terminal
18 pull-up resistors. Further, 20 is an inverter that inverts the signal input from the input terminal 18, 21 and 22 are resistors and capacitors that configure an integrating circuit that integrates the output signal of the inverter 20, and 23 is a signal and a signal input from the input terminal 18. An AND gate that is ANDed with the output signal of the integrating circuit. These circuit elements 20 to 23 form the edge detection circuit 11. 24 is an inverter that inverts the signal input from the input terminal 18, 25 and 26 are input terminals
A resistor and a capacitor that configure an integrating circuit that integrates the signal input from 18, and 27 is an AND gate that takes the logical product of the output signal of the inverter 24 and the output signal of this integrating circuit. These circuit elements 24-27 are the edge detection circuit 12
Are configured.

28 is a retriggerable one-shot multivibrator that generates a pulse for a predetermined period triggered by the output signal of the edge detection circuit 11, and 29 and 30 are semi-fixed resistors and capacitors that set the pulse generation period of the multivibrator 28. , In this case, the pulse generation period is 8
It is set to seconds. These circuit elements 28 to 30 form an 8-second timer 13. 31 is a retriggerable one-shot multivibrator that generates a pulse for a predetermined period triggered by the output signal of the edge detection circuit 12, 32 and 33 are semi-fixed resistors and capacitors that set the pulse generation period of the multivibrator 31, and In this case, the pulse generation period is set to 4 seconds in advance. These circuit elements 31 to 33 form a 4-second timer 14.

Further, 34 is an output signal of the edge detection circuit 11 and a 4-second timer.
A NAND gate to which the output signal of 14 is input, 35 is a NAND gate to which the output signal of the edge detection circuit 12 and an output signal of the 8-second timer 13 are input, and 36 is a NAND gate to which the output signals of the NAND gates 34 and 35 are input. These circuit elements 34 to 36 form the logic circuit 15. Further, 37 is an output signal of the logic circuit 15, that is, an output terminal for outputting an alarm signal.

In addition, 38 is an input terminal for inputting an alarm signal, 39 is a one-shot multivibrator that generates a pulse for a predetermined period triggered by a signal input from the input terminal 38, and 40 and 41 are pulse generation of the multivibrator 39. A semi-fixed resistor and a capacitor that set a period, 42 is a transistor that is turned on / off by the output signal of the multivibrator 39, and 43 is a buzzer that generates sound by the on / off operation of the transistor 42.

In such a configuration, first, the discriminator 2 radiates ultrasonic waves and the like using the sensor 1. As a result, the ultrasonic waves and the like are reflected by the vehicle 5 in front of the vehicle 5, and the reflected wave signal is input to the sensor 1 again. Next, the discriminator 2 measures the inter-vehicle distance Sx between the vehicle 4 and the vehicle 5 based on the propagation time of the reflected wave signal and the like. When the inter-vehicle distance Sx is shorter than a predetermined distance So set in advance, an “L” level signal is output as a determination signal via the transistor 16 and the output terminal 17 when the inter-vehicle distance Sx is longer than the predetermined distance So. Output.

Next, the discrimination signal is input from the input terminal 18 of the alarm signal generator 10. The edge detection circuit 11 detects the rising edge of this discrimination signal and outputs a rising pulse corresponding to this. This rising pulse is a predetermined distance So
This corresponds to the fact that the vehicle-to-vehicle distance Sx between the vehicle 4 and the vehicle 5, which is shorter than the above, becomes longer, that is, the proximity state is changed to the isolated state. On the other hand, the edge detection circuit 12 detects a rising edge of the discrimination signal and outputs a falling pulse corresponding to the rising edge. This falling pulse is longer than the predetermined distance So until then, the inter-vehicle distance Sx between the vehicle 4 and the vehicle 5
Corresponds to the shortened state, that is, the change from the isolated state to the close state.

Further, the rising pulse is input to the 8-second timer 13. The 8-second timer 13 is triggered by the rising pulse and outputs an "L" level signal for 8 seconds. When a rising pulse is input again while this signal is being output, it is retriggered by the pulse and the "L" level signal is output again for 8 seconds from that time.

On the other hand, the falling pulse is input to the 4-second timer 14.
The 4-second timer 14 is triggered by the falling pulse, and
Outputs "L" level signal for 2 seconds. When a falling pulse is input again while this signal is being output, it is retriggered by the pulse and the "L" level signal is output again for 4 seconds from that time.

Next, the rising pulse, the falling pulse, and the output signals of the 8-second timer 13 and the 4-second timer 14 are input to the logic circuit 15, respectively. 8 seconds timer from this logic circuit 15
A pulse is generated when a falling pulse is generated when the "H" level signal is output from 13 and when a rising pulse is generated when the "H" level signal is output from the 4-second timer 14. Is output. This is a case where the inter-vehicle distance Sx between the vehicle 4 and the vehicle 5 changes from the close state to the isolated state, and after 8 seconds or more has passed, the state changes again to the close state.
After 4 seconds or more after changing from the isolated state to the close state,
It corresponds to the case of changing to the isolated state again. That is, it corresponds to the above-mentioned two conditions of the proximity alarm and the isolation alarm. Then, this pulse is output from the output terminal 37 as an alarm signal.

Further, this alarm signal is input to the alarm device 3. The multivibrator 39 in the alarm device 3 is triggered by the alarm signal, outputs a signal of "H" level for a predetermined period, and turns on the transistor 42 only for the predetermined period. This makes the buzzer 43
Operates to generate sound for this predetermined period. This predetermined period of time is a time such that the driver of the vehicle 4 can recognize the sound generated by the buzzer 43, for example, about 3 seconds in advance with the semi-fixed resistance 40
It is set by adjusting the resistance value of.

Although the above description is for the case where the alarm signal generator 10 of FIG. 1 is configured by the hard logic as shown in FIG. 2, the alarm signal generator 10 is configured by the central processing unit (CPU) and memory. However, this operation may be programmed. The operation of this device will be described below with reference to the flowchart of FIG. When the device is powered on, the CPU first proceeds to the process of step S1 and determines whether or not a determination signal has been input. If the result of this determination is "NO", the same determination is repeated until it becomes "YES". That is, it is determined whether the inter-vehicle distance Sx has changed from the close state to the isolated state or from the isolated state to the close state with respect to the predetermined distance So. Next, when the determination result of step S1 is "YES", the process proceeds to step S2. In step S2, an edge pulse is generated from the edge of the input discrimination signal, and then the process proceeds to step S3. In step S3, it is determined whether the edge pulse is a rising edge pulse. That is, it is determined whether the vehicle 4 and the vehicle 5 have changed from the close state to the isolated state. And this judgment result is "YE
In the case of “S”, the process proceeds to step S4. In step S4, 8
Determine if the seconds timer is running. That is, it is determined whether or not the proximity state changes to the isolated state, the proximity state changes within 8 seconds, and the isolation state changes again. Then, if the result of this determination is "NO", the flow proceeds to step S5. In step S5, it is determined whether or not the 4-second timer is operating. That is, it is determined whether or not the isolated state is changed to the close state and the isolated state is changed within 4 seconds. If the result of this determination is "NO", that is, if the state changes from the isolated state to the proximity state and then changes to the isolated state again after 4 seconds or more, that is, if the above-mentioned conditions for the isolation alarm are satisfied. Is the step
Go to S6. In step S6, after outputting the alarm signal, the process proceeds to step S7. On the other hand, the judgment result of step S5 is "YE
In the case of "S", the process proceeds to step S7.

On the other hand, if the result of the determination in step S4 is "YES", that is, if it is detected from this determination that the proximity, the proximity, and the isolation are repeated within 8 seconds,
Proceed to S7. In step S7, after the 8-second timer is activated, the process returns to step S1.

On the other hand, when the result of the determination in step S3 is "NO", the process proceeds to step S8. In step S8, it is determined whether or not the 4-second timer is operating. That is, it is determined whether or not the isolated state is changed to the proximity state, changed to the isolated state within 4 seconds, and then changed to the proximity state again. Then, if the result of this determination is "NO", the flow proceeds to step S9. In step S9, it is determined whether the 8-second timer is operating. That is, it is determined whether the proximity state has changed to the isolated state and the proximity state has changed within 8 seconds. And when this judgment result is "NO", that is,
After changing from the proximity state to the isolated state, the state changes again to the proximity state after 8 seconds or more, that is, when the above-mentioned condition of the proximity alarm is satisfied, the process proceeds to step S10. Step S10
Then, after outputting the alarm signal, the process proceeds to step S11. On the other hand, if the result of the determination in step S9 is "YES", then the process proceeds to step S11.

On the other hand, if the determination result of step S8 is “YES”, that is, if it is detected from this determination that repeated isolation, proximity, isolation, and proximity are repeated within 4 seconds,
Proceed to S11. In step S11, after the 4-second timer is activated, the process returns to step S1.

Since this device operates as described above, as shown in FIG. 8 (c), after the vehicle 4 and the vehicle 5 travel with a sufficient inter-vehicle distance, the vehicle 5 receives the signal at the intersection or the like. In the situation where the vehicle 4 stops near the vehicle 5 due to the stop, and the vehicle 5 starts after the stop signal for a long time and the signal changes,
First, when the vehicle 4 stops near the vehicle 5, the condition of the proximity warning is satisfied, so that an alarm is issued. Next, after the vehicle 5 and the vehicle 4 have come close to each other and stopped for a long time, when the vehicle 5 starts, the condition of the isolation warning is satisfied, so that the alarm is issued. 8th
The mark ● and the mark ○ in Fig. (C) indicate the times when the proximity alarm and the isolation alarm are issued, respectively.

On the other hand, as shown in FIGS. 8 (b) and (i), in a situation where the proximity state and the isolation state are repeated in a short time, the conditions of the proximity alarm and the isolation alarm are not satisfied, so that the vehicle 4 first No alarm is issued except when it is close to 5.

In this way, when the driver's attention is distracted because the driving operation does not change for a long time, an alarm is issued, and there is a change in driving operation such as repeated acceleration and deceleration of the vehicle speed No alarm is given when paying attention. In the example of the traveling pattern shown in FIG. 8, the times when the isolation alarm and the proximity alarm are generated by the present invention are shown by the circles and the circles, respectively. In this figure, the number of ○ and ● marks is 12 in total.

By the way, when an isolation alarm and a proximity alarm are generated when the above-mentioned conventional device is used, * marks and # marks are generated, respectively.
When indicated by a mark, an alarm is generated at all of the changes from proximity to isolation (* mark) and from isolation to proximity (# mark), so the total number of * and # marks is 38, This is more than three times that when using the device of this invention.

Therefore, by using this device, a minimum warning is given to the driver when he / she needs to be alerted. Therefore, the stress caused by unnecessary warning is increased, the driver ignores the warning, or the power of the device is bothered due to annoyance. Appropriate alarms will be given to prevent disconnections.

In the above-described embodiment, the alarm is issued when both the proximity state and the isolated state occur, but the alarm may be issued only in either one of the states.

Next, an alarm for the driver of the following vehicle will be described. FIG. 4 is a block diagram showing the structure of an inter-vehicle distance warning device according to an embodiment of the second invention. In this figure, parts corresponding to the parts in FIG. Is omitted. The difference between the inter-vehicle distance warning device shown in this figure and that shown in FIG.
14 and the logic circuit 15 are removed, and a warning light 6 and a logic circuit 44 are newly provided. Of these, the warning light 6 is the same as the warning light 6 of FIG. Further, FIG. 5 is an example of a partial concrete circuit diagram of FIG. 4, and in this figure, parts corresponding to the respective parts of FIG. 2 are designated by the same reference numerals, and description thereof will be omitted. 2 is different from that shown in FIG. 2 in that an alarm device 3, a 4-second timer 14 and a logic circuit 15 are removed, and an alarm lamp 6 and a NAND gate 45 are newly provided. is there. Further, in the alarm light 6, 46 is an input terminal for inputting an alarm signal, 47 is a one-shot multivibrator which generates a pulse for a predetermined period by being triggered by a signal input from the input terminal 46, and 48 and 49 are multivibrator. Semi-fixed resistors and capacitors that set the pulse generation period of 47,
Reference numeral 50 is a transistor that is turned on / off by the output signal of the multivibrator 47, and 51 is a lamp that is turned on by the on / off operation of the transistor 50.

In such a configuration, first, the discriminator 2 radiates ultrasonic waves and the like using the sensor 1. As a result, the ultrasonic waves and the like are reflected by the vehicle 5 in front of the vehicle 5, and the reflected wave signal is input to the sensor 1 again. Next, the discriminator 2 measures the inter-vehicle distance Sx between the vehicle 4 and the vehicle 5 based on the propagation time of the reflected wave signal and the like. When the inter-vehicle distance Sx is shorter than a predetermined distance So set in advance, an “L” level signal is output as a determination signal via the transistor 16 and the output terminal 17 when the inter-vehicle distance Sx is longer than the predetermined distance So. Output.

Next, the discrimination signal is input from the input terminal 18 of the alarm signal generator 10. The edge detection circuit 11 detects the rising edge of this discrimination signal and outputs a rising pulse corresponding to this. This rising pulse is a predetermined distance So
This corresponds to the fact that the inter-vehicle distance Sx, which was shorter than the above, has become longer, that is, the proximity state has changed to the isolated state. On the other hand, the edge detection circuit 12 detects the falling edge of the discrimination signal and outputs a falling pulse corresponding to this. This falling pulse corresponds to the fact that the inter-vehicle distance Sx, which has been longer than the predetermined distance So until then, has become shorter, that is, that the isolated state has changed to the close state.

Further, the rising pulse is input to the 8-second timer 13. The 8-second timer 13 is triggered by the rising pulse and outputs an "L" level signal for 8 seconds. When a rising pulse is input again while this signal is being output, it is retriggered by the pulse and the "L" level signal is output again for 8 seconds from that time.

The NAND gate 45 then has a falling pulse and 8
The output signal of the second timer 13 is input. A pulse is output from the NAND gate 45 when a falling pulse is generated while the "H" level signal is output from the 8-second timer 13. This corresponds to the case where the inter-vehicle distance Sx changes from the proximity state to the isolated state, and after 8 seconds or more has elapsed, the state changes again to the proximity state. That is, it corresponds to the condition of the proximity alarm described above. Then, this pulse is output from the output terminal 37 as an alarm signal.

Further, this alarm signal is input to the alarm lamp 6. The multivibrator 47 in the alarm lamp 6 is triggered by the alarm signal, outputs a signal of "H" level for a predetermined period, and turns on the transistor 50 only for the predetermined period. This allows the lamp
51 lights up. This predetermined period is set by adjusting the resistance value of the semi-fixed resistor 48 in advance to such a time that the driver of the vehicle 7 can recognize the lighting of the lamp 51, for example, about 3 seconds.

The above description is for the case where the alarm signal generator 10 of FIG. 4 is configured by the hard logic as shown in FIG. 5, but the alarm signal generator 10 is configured by the central processing unit (CPU) and memory etc. However, this operation may be programmed. The operation of this device will be described below with reference to the flowchart of FIG. When the device is powered on, the CPU first proceeds to the process of step S1 and determines whether or not a determination signal has been input. If the result of this determination is "NO", the same determination is repeated until it becomes "YES". That is, it is determined whether the inter-vehicle distance Sx has changed from the close state to the isolated state or from the isolated state to the close state with respect to the predetermined distance So. Next, when the determination result of step S1 is "YES", the process proceeds to step S2. In step S2, an edge pulse is generated from the edge of the input discrimination signal, and then the process proceeds to step S3. In step S3, it is determined whether the edge pulse is a rising edge pulse. That is, it is determined whether the vehicle 4 and the vehicle 5 have changed from the close state to the isolated state. And this judgment result is "YES"
In the case of, it progresses to step S4. In step S4, after the 8-second timer is activated, the process returns to step S1.

On the other hand, if the result of the determination in step S3 is "NO", then the process proceeds to step S5. In step S5, it is determined whether the 8-second timer is operating. That is, it is determined whether the proximity state has changed to the isolated state and the proximity state has changed within 8 seconds. Then, if this determination result is "YES", the process returns to step S1. On the other hand, if the determination result in step S5 is "NO", that is, after changing from the proximity state to the isolated state, the state changes to the proximity state again after 8 seconds or more, that is, the condition of the proximity alarm described above is satisfied. If so, go to step S6. Step
In S6, after outputting the alarm signal, the process returns to step S1.

Since this device operates as described above, it is not necessary to frequently give an alarm to the following vehicle 7. Therefore, the driver of the following vehicle 7 will not ignore this warning, and the driver of the following vehicle 7 can be properly alerted.

By the way, in the example of the traveling pattern shown in FIG. 8, when the # mark indicates the proximity alarm when the isolated state is changed to the proximity state when the above-mentioned conventional device is used, the total number is 20. On the other hand, when the time when an alarm is issued by this second invention is indicated by a ● mark, the total number of ● marks is 8. Therefore, when the device of the second invention is used, the following vehicle 7
The driver's warning can be reduced to less than half of the conventional level.

Further, since the alarm of the device of the second invention is stopped after about 3 seconds, the driver of the following vehicle 7 can surely confirm this alarm, and there is no disadvantage that the alarm is neglected by the alarm for a long time. . Since the brake lamp is turned on when the vehicle is stopped for a long time, the driver of the following vehicle 7 can sufficiently confirm that the vehicle 4 is stopped.

In the above-described embodiment, the timer time is set to 4 seconds and 8 seconds as the condition of the isolation warning and the proximity alarm, but the condition time of the proximity alarm is set longer than the condition time of the isolation alarm according to the traffic situation of each city. An appropriate time may be selected under the condition that Further, the condition time of the isolation alarm may be changed to 4 to 8 seconds and the condition time of the proximity alarm may be changed to about 8 to 16 seconds so that these times can be set to arbitrary times.

Further, in a situation where the vehicle is continuously traveling with the vehicle in front such as in a rush state, the inter-vehicle distance of each vehicle is so short that other vehicles cannot interrupt it. About half of the total length of
In the experiment, this predetermined distance So is set to 2 meters.
As a result, there is also an advantage that false alarms issued by a person other than the vehicle, such as a fence at a corner, are reduced.

In addition, the lamp 51 shown in FIG. 5 displays yellow characters or the like in the high mount stop lamp 9 as shown in FIG. 7 (a), even if characters such as “Caution” are displayed as shown in FIG. May be provided, or the high mount stop lamp may blink until the brake lamp lights. In the latter case, the brake lamp is lit for about 3 seconds until it is lit, and the brake lamp is lit continuously at the same time. Further, the lamp 51 is attached to the rear spoiler 52 shown in FIG. 7 (b), or together with the stop lamp 54 on the speaker box 53 shown in FIG. 7 (c) and the air purifier 56 shown in FIG. 7 (d). It may be provided in the rear window 55, or may be provided on the rear sun visor or the like at a location sufficiently recognized by the following vehicle. However, since the purpose of this lamp 51 is to draw the attention of the driver of the following vehicle in the proximity state, it is set so that the brightness is not increased more than necessary and the light does not reach far away.

As described above, the inter-vehicle distance warning device according to the first and second aspects of the invention does not operate in a situation where the driver pays attention to the surroundings, and operates in the most distracting state, and therefore occurs in this device. Proximity warning is used to reduce the volume of audio equipment such as car stereo installed in the vehicle for a certain period of time, flashing the certification of the car stereo certification button, or constant if the interior light is on. It is possible to call the driver's attention by making it dark for a while so that the driver can easily see the front. In this case, in order to operate each device using the proximity information,
In the device of the first invention, the output signal of the NAND gate 35 in the alarm signal generator 10 of FIG. 2 may be used, or the flow from step S5 to step S6 in the flow chart of FIG. 3 may be used.

On the other hand, using the isolation alarm generated by this device, the screen of the TV set installed in the vehicle can be erased, the brightness of the screen can be changed, or characters such as "Caution" can be superimposed on the screen. If you do not notice that the vehicle in front of you has departed while watching the television broadcast or video etc., because the driver has stopped for a long time due to traffic jam etc. be able to.

Further, conventionally, in order to drive safely, there is a television system in which a vehicle stop is detected by a speed sensor, a brake sensor, etc., and a television broadcast or video is displayed on the display only while the vehicle is stopped. Also, by inputting the above-mentioned isolation warning to the control device of this system and performing the same processing as described above on the display while the vehicle is stopped, it is possible to call the driver's attention in the same situation as described above.

In this case, in order to operate each device using the isolation information, the device of the first invention uses the output signal of the NAND gate 34 in the alarm signal generator 10 of FIG. 2 or the flowchart of FIG. The flow from step S9 to step S10 may be used.

Further, with regard to the devices of the first and second inventions, it is possible to arbitrarily change the above-mentioned circuit configuration and each circuit within a range not departing from the gist, and to change the logic circuit, the CPU, or the like, or The steps of the flowcharts of FIGS. 3 and 6 may be rearranged or increased, and the steps may be arbitrarily performed.

[Advantage of Device] As described above, according to the first and second devices, the warning is issued when the driver of the vehicle in which this device is mounted and the driver of the following vehicle are driving while paying attention to the surroundings. Is not generated, and an alert is generated in the distracted mental state of these drivers, so these drivers drive with attention to the surroundings without increasing stress even in a rush-like situation. There is an effect that can be. This has the effect of reducing contact accidents between the vehicles.

[Brief description of drawings]

FIG. 1 is a block diagram showing the structure of an inter-vehicle distance warning device according to an embodiment of the first invention, FIG. 2 is a partial concrete circuit diagram of FIG. 1, and FIG. 3 is an alarm signal of FIG. FIG. 4 is a flowchart showing the operation of the generator 10, FIG. 4 is a block diagram showing the structure of an inter-vehicle distance warning device according to an embodiment of the second invention,
FIG. 5 is a partial concrete circuit diagram of FIG. 4, FIG. 6 is a flow chart showing the operation of the alarm signal generator 10 of FIG. 4, and FIG. 7 is a conventional vehicle-mounted device with a lamp 51 of FIG. FIG. 8 is a diagram showing an example in which the vehicle is mounted, FIG. 8, FIG. 9 and FIG. 10 are diagrams showing a traveling condition of the vehicle, and FIG. 11 is a block diagram showing a first configuration example of a conventional inter-vehicle distance warning device, and FIG. FIG. 13 is a diagram showing an example in which the inter-vehicle distance warning device of FIG. 11 is actually installed in a vehicle, and FIG.
FIG. 14 is a flowchart showing the operation of the discriminator 2 in FIG. 11, FIG. 14 is a waveform diagram of signals generated in the discriminator 2 in FIG. 11, and FIG.
FIG. 16 is a block diagram showing a second configuration example of a conventional inter-vehicle distance warning device, FIG. 16 is a diagram showing an example in which the inter-vehicle distance warning device of FIG. 15 is actually mounted on a vehicle, and FIG. 17 is FIG. Discriminator 2
18 is a waveform diagram of a signal generated in the discriminator 2 of FIG. 15, and FIG. 19 is a diagram showing an example of the warning light 16 of FIG. 1 ... Sensor, 2 ... Discriminator (discriminating means), 3 ... Alarm device (alarm generating means), 6 ... Alarm light (alarm generating means),
10 ... Alarm signal generator, 11, 12 ... Edge detection circuit (first and second detection means), 13 ... 8 second timer (first time measuring means, time measuring means), 14 ... 4 second timer (Second timekeeping means), 15, 44 ... Logic circuit (alarm generating means).

Claims (2)

[Scope of utility model registration request] 1. An inter-vehicle distance to a vehicle ahead is measured, and the inter-vehicle distance is compared with a predetermined distance set in advance. When the inter-vehicle distance is shorter than the predetermined distance, a first value is obtained. A discriminating means for outputting a discriminating signal having a second value when the inter-vehicle distance is longer than the predetermined distance, and a change in the discriminating signal from the first value to the second value is detected to detect the first signal. First detecting means for outputting, second detecting means for detecting a change from the second value to the first value of the discrimination signal and outputting a second signal, and generation of the first signal A first timing means for timing a first predetermined period from time, a second timing means for timing a second predetermined period from the time when the second signal is generated, and the second timing after the first predetermined period has elapsed. And the case where the first signal is generated after the second predetermined period has elapsed. Distance warning device characterized by comprising a warning generating means for generating an alarm when one of Kutomo. 2. An inter-vehicle distance to a vehicle ahead is measured, and the inter-vehicle distance is compared with a preset predetermined distance. When the inter-vehicle distance is shorter than the predetermined distance, the first value is obtained. A discriminating means for outputting a discriminating signal having a second value when the inter-vehicle distance is longer than the predetermined distance, and a change in the discriminating signal from the first value to the second value is detected to detect the first signal. First detecting means for outputting, second detecting means for detecting a change from the second value to the first value of the discrimination signal and outputting a second signal, and generation of the first signal An inter-vehicle distance warning device, comprising: a time measuring unit that measures a predetermined period from time, and an alarm generating unit that gives an alarm to a driver of a following vehicle when the second signal is generated after the predetermined period has elapsed. .