JPS61129351A - Vehicle periphery monitoring device - Google Patents

Abstract

PURPOSE:To prevent the repeated operation of an alarming device by continuing alarming for a preset time of period when the distance up to an obstacle goes below preset distance and an alarm is given once and subsequently even when the distance up to the obstacle is increased slightly further than the preset distance. CONSTITUTION:The distance up to an obstacle is detected by a sensor 13a and the detection signal is converted to a voltage signal by a processing circuit 14a. This voltage signal becomes lower than the reference voltage of an op amplifier 15a. In other words, when the distance up to the obstacle becomes lower than the preset distance, the op amplifier 15a output a signal. As a result, a light emitting diode 65a emits light and makes a display and operates a timer 30a. The timer 30a issues an output signal only for a fixed period of time and operates an alarming device 40. Once the alarming device 40 has been operated, the timer 30a operates the alarming device 40 for a fixed period of time. Then, even when the distance up to the obstacle is varied slightly approximately for the preset distance, the alarming device 40 does not perform the repeated operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device that warns when an obstacle exists around a vehicle.

[Conventional technology]

In this type of vehicle surroundings monitoring device, an alarm device is continuously activated when an obstacle exists around the vehicle.

In response to this, the applicant proposed in Japanese Patent Application No. 59-9047 that an alarm device is activated only for a certain period of time.

According to this, if a warning is issued for a certain period of time when you want your vehicle to approach an obstacle, such as when parking in a garage,
Since the warning is not issued after that, it is possible to prevent the driver from feeling that the warning is noisy.

[Problem that the invention seeks to solve]

However, even if the vehicle is equipped with a vehicle surroundings monitoring device that issues an alarm for a certain period of time, the alarm may be issued repeatedly if the vehicle is stopped exactly at the location where the alarm was issued. For example, if a warning is to be issued when the distance between the obstacle detection sensor and the obstacle is within 20IIJ, if the distance is exactly 20C11
When the vehicle is stopped at a location, an alarm will be activated for a certain period of time. Then, for some reason, the vehicle moved slightly, and the distance between the sensor and the obstacle became 20.5 c+++.
Then, when the vehicle moves again and the distance becomes 20 cm, the alarm is issued again. This degree of vehicle movement easily occurs in vehicles with automatic transmissions due to changes in the vehicle's attitude when the shift lever is operated between the drive or reverse position and the neutral or parking position. , also caused by uneven road surfaces.

Therefore, an object of the present invention is to prevent repeated warnings from being issued in a vehicle surroundings monitoring device in which warnings are issued only for a certain period of time.

[Means for solving problems]

Therefore, in the present invention, once a warning is issued, even if the distance to the obstacle becomes greater than the distance at which the warning is issued,
If it is small, it is as if the distance did not become large (
It is characterized by continuing the signal state when the alarm was first issued.

Specifically, the present invention includes a detection means installed on a vehicle body that emits a detection signal when the distance to an obstacle is smaller than a set distance; In a vehicle surroundings monitoring device that includes a timer that issues a time signal for a certain period of time after the timer has passed, and an alarm that operates in response to the time signal from the timer and issues an alarm, when the detection means issues the detection signal, The set distance in the detection means or the signal representing the distance to the obstacle in the detection means is changed by a predetermined value so that the detection signal continues to be emitted even if the distance to the obstacle becomes larger than the set distance. It is characterized by providing a changing means.

[Effect]

While the distance from the sensor of the detection means to the obstacle is greater than a predetermined set distance, the detection means does not generate a detection signal and no alarm is issued. When the vehicle and the obstacle approach and the distance to the obstacle becomes smaller than the set distance, the detection means issues a detection signal and a warning is issued for a certain period of time.

In this way, once the alarm is issued, the vehicle will stop near the position where the distance to the obstacle is the set distance, and then for some reason the vehicle will move slightly in the direction of changing the distance to the obstacle. However, even if the distance to the obstacle changes around the set distance, the changing means allows the detection signal from the detection means to continue being emitted, so at this time,
The alarm will not be activated in reverse. In other words, a warning is issued for a certain period of time from the time when the distance to the obstacle first becomes smaller than the set distance, and thereafter no warning is issued.

The changing means increases the set distance in the detecting means by a predetermined value, or decreases the signal representing the distance to the obstacle in the detecting means by a predetermined value.

However, if the vehicle and the obstacle are far apart, the detection means will no longer generate a detection signal, and the next time an alarm will be issued will be when the distance to the obstacle becomes smaller than the set distance.

〔Example〕

Hereinafter, embodiments of the present invention will be explained with reference to the drawings.6 Fig. 1 is a block diagram showing a first embodiment of the present invention, and in this embodiment, four detection means are provided. however,
Since the configurations of each of the detection means 10a to 10d are all the same, only the configuration of the detection means 10a will be shown in detail, and the configurations of the other detection means 10b to 10d will be omitted.

One detection means 10a includes a sensor 13a, and the sensor 13a is connected to a processing circuit 14a. In this case, the sensor 13a is an ultrasonic transmitter/receiver, and generates pulsed ultrasonic waves in a predetermined direction at certain time intervals according to a signal from the processing circuit L4a, and detects when the ultrasonic waves hit an obstacle. Upon receiving the reflected light, the processing circuit 14
Send the received signal to a. The processing circuit 14a then obtains a voltage signal proportional to the time from transmission to reception of the ultrasound. Since the time from transmission to reception of ultrasonic waves is proportional to the distance to the obstacle, the voltage signal output from the processing circuit 14a is proportional to the distance to the obstacle.

FIG. 2 schematically shows a plan view of the vehicle, and as is clear from this figure, the sensors 13a to 13d of each of the detection means 10a to 10d are arranged at the four corners of the vehicle body. Each of the sensors 13a to 13d has a monitoring area diagonally in front or in the rear of the vehicle, and transmits and receives ultrasonic waves toward obstacles existing in that area.

In FIG. 1, reference numeral 15a is an operational amplifier connected to form a comparator, and its inverting input receives a voltage signal from the processing circuit 14a via a resistor 16a, and its non-inverting input receives a resistor. A reference voltage is input from the potentiometer 61 via 17a. Therefore, the operational amplifier 15a is
While the voltage signal from the processing circuit 14a is higher than the reference voltage, the signal rOJ is output at the logic level, but when the voltage signal from the processing circuit 14a becomes lower than the reference voltage, the signal "rOJ" is output at the logic level. 1” signal is output. here,
The logic level rlJ, "0" means that the voltage level is "higher" or "lower" than a predetermined voltage level, respectively. It will be used in the same way below. Since the output of the operational amplifier 15a becomes a detection signal of the detection means 10a, the reference voltage corresponds to the set distance. The set distance in this case is, for example, about 20 cm.

Further, a potentiometer 51. which constitutes the changing means 50a is connected between the output of the operational amplifier 15a and the non-inverting input. a and a resistor 52a are connected so that the output voltage of the operational amplifier 15a influences the voltage level of the non-inverting input of the operational amplifier 15a. That is, the voltage level manually applied to the non-inverting input of the operational amplifier 15a is made higher by a predetermined voltage when the output of the operational amplifier 15a is "1" than when the output of the operational amplifier 15a is the logic rOJ. As a result of increasing the voltage in this way, the set distance is increased. In this case, the predetermined voltage is set to a value that increases the set distance by 1 cm, for example. In addition, to be more specific, the operational amplifier,
When the operational amplifier 15a is outputting a logic rOJ signal, the voltage level input to the non-inverting input of the operational amplifier 15a is a voltage slightly lower than the above-mentioned reference voltage. Therefore, when setting the reference voltage, it is necessary to take this decrease into consideration.

The output of the operational amplifier 15a is connected to the cathode of a light emitting diode 65a via an inverting circuit 64a, and the anode of the light emitting diode 65a is connected to a positive power source via a resistor 66a. Further, the output of the operational amplifier 15a is connected to a timer 30a consisting of a monostable circuit, and the output of the timer 30,1 is connected to an OR gate 62 and an inverting circuit 63.
is connected to one end of an alarm device 40 consisting of a buzzer.

The other end of the alarm device 40 is connected to a positive power source. Therefore, while a logic "0" signal is output from the operational amplifier 15a, a logic "1" signal, that is, a voltage equal to the positive power supply, is applied to the cathode of the light emitting diode 65a, so that the light emitting diode 65a does not emit light. In addition, the timer 30a does not operate, and since a logic "1" signal, that is, a voltage equal to the positive power supply, is applied to one end of the alarm 40, the alarm 40 also does not operate. On the other hand, when the operational amplifier 15a outputs a signal of logic "1", a signal of logic rOJ is applied to the cathode of the light emitting diode 65a, that is, no voltage is applied, so the light emitting diode 65a emits light. Also, at that time, timer 3
Since 0a outputs a logic "1" signal for a certain period of time, a logic "0" signal is applied to one end of the alarm device 40 for a certain period of time, that is, no voltage is applied and the alarm device 40 remains constant. Time operated.

Changing means 50b to 50d and light emitting diodes 65b to 65d connected to other detection means 10b to 10d
, timers 30b to 30d are also completely the same as each configuration described above. Note that the output of each timer 30a to 30d is connected to one inverting circuit 63 and one alarm 40 via one OR gate 62, so that any one of the detection means 10a
When a detection signal of logic "1" is output from ~10d, the alarm 40 is activated for a certain period of time to issue an alarm.

FIG. 3 shows the configuration of the display section 80, and as is clear from this, each of the light emitting diodes 65a to 65d is 1.
The sensors 32 to 13d are arranged on a picture representing the plane of the vehicle, and an alarm 40 is also attached adjacent thereto.

Next, the action will be explained.

If there are no obstacles approaching the four sides of the vehicle, none of the detection means 102-10d will generate a detection signal, and neither the light emitting diodes 65a-65d nor the alarm 40 will be activated.

Now, for example, when an obstacle approaches the diagonally right front of the vehicle and the distance to the sensor 13a becomes smaller than the set distance, the detection means 10a generates a detection signal, that is, the logic "1" is output from the operational amplifier 1.5a. ” signal to cause the light emitting diode 65a to emit light, and at the same time, activate the alarm 40 for a certain period of time. This allows the vehicle occupant to know that there is an obstacle approaching diagonally to the right of the vehicle.

After that, the detection signal continues to be generated and the light emitting diode 65a continues to emit light as long as the obstacle does not move away. but,
The alarm 40 stops operating after a certain period of time, so that the occupant does not feel the alarm is noisy.

After that, when an obstacle approaches the diagonally right rear side of the vehicle, the detection means 10c generates a detection signal. Therefore, the light emitting diode 65c emits light, and the alarm 40 is activated again for a certain period of time, notifying the occupant of the newly approaching obstacle.

In this way, each time there is an obstacle approaching in each direction, the alarm 40 is activated and a warning is issued for a certain period of time.
The occupant can distinguish and recognize obstacles.

By the way, as described above, when the obstacle diagonally to the right of the vehicle approaches the set distance and a warning is issued, if the vehicle is stopped at that moment, the detection means 10a continues to generate a detection signal. At this time, if the vehicle moves slightly away from the obstacle for some reason, the processing circuit 14
The voltage signal output from a slightly decreases and becomes lower than the reference voltage. However, at this time, the operational amplifier 15a has already outputted a logic "1" signal, increasing the voltage input to the non-inverting input of the operational amplifier 15a by a predetermined voltage, so the amount of decrease in the voltage signal from the processing circuit 14a is below a predetermined voltage, the operational amplifier 15a outputs a logic “1” signal;
In other words, the detection signal continues to be generated. Therefore, the light emitting diode 65a continues to emit light, and the alarm 40 is not activated as long as a certain period of time has passed after the obstacle first approaches the set distance.

In this way, the vehicle can be stopped at the location where the warning was issued, and then the shift lever of the automatic transmission can be operated between the drive or reverse position and the neutral or parking position at this location, or when the vehicle is stopped at the location where the warning is issued. Even if the vehicle moves slightly due to
If the change in the distance between a and the obstacle is within a predetermined range, a warning will not be issued every time the vehicle moves (the warning will not be loud for the occupants, or if another obstacle approaches). You can avoid causing people to misunderstand that you have arrived.

However, after that, if the vehicle and the obstacle are far apart, the voltage input to the non-inverting input of the operational amplifier 15a is again set to the reference voltage and returns to the initial state.

FIG. 4 is a block diagram showing a second embodiment of the present invention, in which the detection means 10 is mainly composed of a microcomputer. Further, FIG. 6 shows signal waveforms at each part in FIG. 4, and will be described below with reference to FIG. 6.

Here, 21 is a transmitter, which transmits ultrasonic waves of about 40kHz.
The signal is transmitted in a predetermined direction around the vehicle, for example toward the rear of the vehicle. The transmitter 21 is activated by receiving the output signal S1 of the monostable circuit 23, and the monostable circuit 23
Transmission start command signal S0 from microcomputer 25
In response to this, the signal Sl is output for a certain period of time.

In FIG. 4, 22 is a receiver which receives ultrasonic waves having the same frequency as that transmitted by the transmitter 21, and converts the portion having a predetermined level or higher into a logical signal. Then, the receiver 22 adjusts its reception direction, and the transmitter 21 transmits,
It is designed to receive ultrasonic waves reflected by obstacles existing within a predetermined area.

The signal S4 obtained at the receiver 22 is sent to one input terminal of the Nant gate 26, and the other input terminal 72 of the Nant gate 26 is fed with the signal S2 from the microcomputer 256. The gate signal S2 is configured to rise after a time T1 and fall after a time T2 after the transmission start command signal S0 is generated. Therefore, the electrical signal S4 from the receiver 22 is taken into the next stage circuit only while the gate signal S2 is "1" at the logic level, and is converted into an electrical signal by the receiver 22 during the time T. What is converted into an electrical signal by the receiver 22 after the elapse of time T2 is not captured.

In other words, the signal within time T1 is not reflected by an obstacle, but is rejected as having directly propagated from the transmitter 21 to the receiver 22, and the signal after time T2 is excluded.
This is excluded as being caused by reflected waves from obstacles located further away than the set distance.

In addition, the output signal of the Nant gate 26 is
is sent to one input terminal of This Nant gate 28 is assembled together with the Nant gate 27 to form a flip-flop FF, and when a logic rOJ signal is output from the Nant gate 26, a logic "1" signal is output from the Nant gate 28. S, is output and held in the flip-flop FF. This signal S is then sent to the microcomputer 25. On the other hand, a clear signal S3 for the flip-flop FF is sent from the microcomputer 25 to one input terminal of the Nant gate 27 via the inverting circuit 24.
When the clear signal S, is generated, the output signal S, from the Nant gate 28 is set to logic "0", and the state in which the signal is held by the free-knob flop FF is cleared.

Clear signal S, from gate signal S2 being "1" to rOJ
Occurs immediately after falling.

The microcomputer 25 generates the signals So, St, and S3 at the above timing, and takes in the output signal S from the Nant gate 28 as the output signal of the flip-flop FF according to a program. Then, the output signal S
, and as a result, when it is determined that there is an obstacle within the set distance, an activation signal 56 is sent to the timer 30 consisting of a monostable circuit to activate the alarm 40 for a certain period of time.

FIG. 5 shows the program contents of the microcomputer 25.

When this program is started, first, step 101
is processed, and each part of the microcomputer 25 is initialized. Thereafter, the processes from step 102 onwards are repeatedly executed.

In step 102, a transmission start command signal S0 is generated,
The monostable circuit 23 is then caused to generate a signal SI at time T0, and the transmitter 21 is caused to transmit a pulsed ultrasonic wave at time T0. Next, in step 103, it is determined whether the timer counter CT has reached T1 or more. timer counter C
T is cleared and activated by the initialization in step 101, and when time T3 has elapsed and the count value of the timer counter CT exceeds T, the process proceeds to step 104, where the gate signal St is set to logic "1'', the Nantes gate 26 is opened. Then, in step 105, wait for 72 hours to pass, and
When two hours have elapsed, in step 106, the gate signal Sz is set to logic "0", and the Nantes gate 26 is brought into the gate closed state, but before that, steps 121 to
At 124, 72 hours is determined.

First, in step 121, it is determined whether flag F is set. When flag F is set, it is used to remember that the existence of an obstacle was confirmed during the previous process.If flag F is set, step 1 is executed.
21 is determined in the affirmative, and in step 122, t is set to a predetermined value α. If the flag F is not set, step 121 is determined in the negative, and in step 123, t is set to "0". Then, in step 124,
Time T2 is determined by 10+1. Here, to
is determined to match the time required for an ultrasonic wave transmitted when the obstacle is exactly at a set distance to be reflected by the obstacle and received. For example, the time required for an ultrasonic wave to travel back and forth over a distance of 1 cm is determined.

Next, in step 107, a clear signal S is generated to clear the flip-flop FF and return the flip-flop FF to its initial state. Then, in step 108, the output signal S of the flip-flop FF is taken in, and it is determined whether the signal S is the logic rlJ.

This signal S is obtained by holding the signal S4 output from the receiver 22 by the flip-flop FF while the Nant gate 26 is in the open state.
If it is a logic "1", it means that there is an obstacle within the set distance, and if it is a logic "0", it means that there is no obstacle within the set distance. Therefore, when step 108 is determined to be affirmative, a signal of logic rlJ is output as signal S6 in step 109, and when step 08 is determined to be negative, a signal of logic "0" is output as signal S6 in step 110. Output. The timer 30 is activated when the signal S is a logic "1" and deactivated when the signal S is a logic "1". And timer 3
0 sends an activation signal to the alarm 40 for a certain period of time during its operation, and issues a warning to the occupants.

When step 109 has been processed, a flag F is set in step 125 to remember that an obstacle has been detected and a warning has been issued, and when step 110 has been processed, in step 126, Reset flag F and remember that no obstacle was detected.

Next, in step 111, the process waits for the time T to elapse, and then proceeds to step 112, where a timer counter CT for measuring time is cleared. After this, the process of step 102 is performed again, and as a result, the transmitter 21 transmits ultrasonic waves every time T3.

In FIG. 6, two transmissions of ultrasonic waves by the transmitter 21 are shown. During the first transmission, an obstacle is detected, a signal S4 is obtained from the receiver 22, and the microcomputer 2
5, the gate open time T2 of the gate signal S2 when the ultrasonic wave is transmitted next time is made slightly longer by t than the first time. As a result, the obstacle is detected and the vehicle is stopped at the moment the warning is issued.
Even if the vehicle subsequently moves slightly, for example, by about 1 cffI, in a direction that increases the distance between the vehicle and the obstacle, the obstacle can be continuously detected as existing within the set distance.
It is possible to prevent a warning from being issued every time the vehicle moves slightly.

However, if the vehicle and the obstacle become far apart after that, the gate opening time T2 is returned to the original time.

In addition, in the flowchart of FIG. 5, step 12
Processes 1 to 126 correspond to the changing means of the present invention.

Furthermore, FIG. 7 is a block diagram showing a third embodiment of the present invention. In this embodiment, there is only one detection means 1O, but its configuration is the same as that described in FIG. 1.

Here, between the output of the operational amplifier 15 and the inverting input,
A changing means 50 is connected. The changing means 50 is NP
It consists of an N-type transistor 53 and a resistor 54.55, and since the transistor 53 is non-conductive while the operational amplifier 15 is outputting a logic "0" signal, it has no effect on the voltage at the inverting input. However, when the operational amplifier 15 outputs a logic "1" signal, the transistor 53 becomes conductive and slightly lowers the voltage at the inverting input.

Therefore, while the operational amplifier 15 is not generating a logic "1" signal, that is, a detection signal, and no alarm is issued, the distance signal output from the processing circuit 14 of the detection means 10 is directly transmitted to the operational amplifier 15. The voltage is input to the inverting input of the operational amplifier 15 and compared with the reference voltage of the non-inverting input. Then, when there is an obstacle approaching the vehicle, the voltage of the distance signal gradually decreases, and the distance to the obstacle reaches the set distance, and the voltage of the distance signal becomes lower than the reference voltage, the operational amplifier 15 outputs the logic "1". ” signal, and the timer 30 operates the buzzer 40 for a certain period of time. In other words, give an alarm.

In this way, when the operational amplifier 15 outputs a logic "1" signal, the voltage from the processing circuit 14 is reduced by the changing means 50, so that even if the distance to the obstacle becomes slightly larger, the operational amplifier 15 continues to output a logic "1" signal.

Therefore, in this embodiment, as in the two embodiments described above, the vehicle is stopped the moment the warning is issued, and even if the vehicle moves slightly thereafter for some reason, the warning is repeatedly issued. Never.

[Effect of idea]

As described above, according to the present invention, once the distance to the obstacle becomes smaller than the set distance and an alarm is issued, even if the distance to the obstacle becomes larger than the set distance thereafter, the alarm will be issued only slightly. If so, the detection signal will continue to be generated as if the distance had not increased, so even if the vehicle is stopped at a position where the distance to the obstacle is close to the set distance, and the vehicle moves slightly at that position, The warning is issued only for an initial fixed period of time, and is not repeated thereafter, so that the vehicle occupants do not feel the alarm is noisy.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a first embodiment of the present invention;
FIG. 3 is an explanatory diagram showing the mounting position of the sensor in the first embodiment, FIG. 3 is an explanatory diagram showing the configuration of the display section in the first embodiment, and FIG. 4 is a diagram showing the second embodiment of the present invention. 5 is a flow chart showing the program contents of the microcomputer of the second embodiment, FIG. 6 is a time chart showing signal waveforms of each part in FIG. 4, and FIG. 7 is a flow chart showing the program contents of the microcomputer of the second embodiment. FIG. 2 is a block diagram of an embodiment. 10.--1--Detection means 30--Timer 40--Alarm device 50-1--Changing means Applicant, Toyota Motor Corporation Co., Ltd. Fig. 2 Fig. 3 3541 Fig. n π0 Fig. 8, 8 ” 1 ° 1 悄 --

Claims (1)

[Scope of Claims] 1. A detection means installed on the vehicle body that emits a detection signal when the distance to the obstacle is smaller than a set distance; In a vehicle surroundings monitoring device comprising: a timer that issues a timed signal for a certain period of time; and an alarm that operates upon receiving the timed signal from the timer and issues an alarm; A change in which the set distance in the detection means or the signal representing the distance to the obstacle in the detection means is changed by a predetermined value so that the detection signal continues to be emitted even if the distance to the object becomes greater than the set distance. A vehicle surroundings monitoring device characterized by comprising means.