JPH10213659A - Ultrasonic wave type obstacle detecting device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discriminate operation state appropriately by providing a control means wherein an obstacle detection operation is stopped when a vehicle speed is above a specified value and the fact that detection operation is stopped is reported. SOLUTION: An ultrasonic wave signal is emitted from a microphone 1, and the reflected wave from an obstacle is received with the microphone 1. The reception signal is, through an amplification circuit 14, etc., introduced to a calculation circuit 2, and the calculation circuit 2 calculates a distance based on the period required for the reflection signal to comeback. When the distance is within a specified range, the presence of an obstacle together with distance are displayed on a display means 32 through a switching circuit 31. A vehicle speed judging circuit 3 (control means) does not issue the output for operating the switching circuit 31 while a vehicle speed is above a specified level, even if the calculation circuit 2 judges that an obstacle is within a specified range. Further, the vehicle speed judging circuit 3 operates a display means 34 through a switching circuit 333, to report that obstacle detection operation is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic obstacle detecting device for a vehicle, which detects an obstacle by attaching an ultrasonic sensor to the front and rear of the body of an automobile or the like.

[0002]

2. Description of the Related Art An ultrasonic obstacle detecting device which mounts an ultrasonic sensor on the front of a vehicle body to detect an obstacle in front of the vehicle body picks up a wind noise during high-speed running or a microphone in the ultrasonic sensor vibrates due to wind pressure. If the speed exceeds a certain speed (usually about 10 km / h), the detection operation is stopped.

Further, when the power is turned on, a system check operation such as a disconnection is first performed, and thereafter, a normal obstacle detection operation is performed.

[0004]

However, if the operation is stopped when the vehicle speed exceeds a certain speed, it is difficult to determine when the vehicle speed is near the certain speed. In other words, there is a situation in which it is impossible to know whether an alarm indicating the presence of an obstacle is not issued because there is no obstacle, or whether an alarm is not output even if there is an obstacle because the vehicle speed is higher than a certain speed.

Further, if the power is turned off after the power is turned off because the vehicle is stopped near an obstacle or the like, the obstacle detection operation does not start during the system check operation. For this reason, a situation occurs in which an alarm is not output in spite of the presence of an obstacle, and the vehicle may hit the obstacle.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle obstacle detection device capable of more accurately determining an operation state. An object of the present invention is to provide a vehicle obstacle detection device that can accurately detect an obstacle when the power is turned on after the start of traveling.

[0007]

According to a first aspect of the present invention, there is provided an ultrasonic obstacle detecting apparatus for a vehicle, which detects an obstacle based on an output of an ultrasonic sensor for detecting a reflected wave of a transmitted ultrasonic signal. The apparatus is characterized in that it has a control means for detecting the vehicle speed of the vehicle and stopping the obstacle detection operation when the vehicle speed is equal to or higher than a certain value and notifying that the detection operation is being stopped. If the vehicle speed is equal to or higher than a certain value, the user is notified that the obstacle detection operation is not being performed.

According to a second aspect of the present invention, an obstacle is detected by an output of an ultrasonic sensor for detecting a reflected wave of the transmitted ultrasonic signal, and a system check operation for detecting a device abnormality is performed when the power is turned on. The ultrasonic obstacle detecting device for a vehicle includes a control unit that detects a vehicle speed of the vehicle at a time when the power is turned on, and omits a system check operation and starts an obstacle detecting operation when the vehicle speed is a certain value or more. The feature is that it is. If the vehicle is already moving when the power is turned on, the obstacle detection operation has priority over the system check operation.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described. In FIG. 1, reference numeral 1 denotes a timing signal generating circuit 10, a monostable multivibrator 11, an oscillating circuit 12, and an output circuit 13 for generating an ultrasonic signal. The microphone emits and detects a reflected wave from an obstacle, and a signal received by the microphone is guided to the arithmetic circuit 2 through an amplifier circuit 14, a detection circuit 15, and a waveform shaping circuit 16. The operation circuit 2 includes a timing signal generation circuit 10
The counting is started by the signal from the controller, and the distance is calculated from the time t until the reflected signal returns. If the distance is within a predetermined distance, the notifying unit 32 notifies (displays) the presence of the obstacle and the distance (in the case where a plurality of ultrasonic sensors are installed, the direction of the obstacle) through the switching circuit 31. 2A and 2B are timing charts showing the above operation. FIG. 2A shows the output of the timing signal generation circuit 10, FIG. 2B shows the output of the monostable multivibrator 11, FIG. 2C shows the output of the output circuit 13, and FIG. (E) shows the output of the detection circuit 15 and (f) shows the output of the waveform shaping circuit 16.

Here, a vehicle speed judging circuit 3 for taking in a vehicle speed signal is inserted between the arithmetic circuit 2 and the switching circuit 31. If the vehicle speed is equal to or higher than a certain speed, the vehicle speed judging circuit 3 may be turned off. Even if the arithmetic circuit 2 determines that the object is within the predetermined distance, the arithmetic circuit 2 does not output an operation for activating the switching circuit 31. If the vehicle speed is equal to or higher than a predetermined speed, the vehicle speed determining circuit 3 notifies Activate the means 34 to notify that the obstacle detection operation has been stopped because the vehicle speed has exceeded a certain speed. Therefore, the driver can recognize the operation state of the obstacle detection based on the vehicle speed.

FIG. 3 shows an embodiment according to the second aspect of the present invention, and a gate circuit 41 in the figure is for a system check operation. This system check operation detects the reverberation component immediately after the ultrasonic oscillation by the microphone as shown in FIG. 4, thereby confirming whether the ultrasonic signal is oscillated and confirming whether there is a disconnection or the like. Yes, the system check operation is first performed immediately after the power is turned on, and the process proceeds to the normal obstacle detection operation only when there is no abnormality. If there is an abnormality, the notification means 3 through the system function display circuit 45 and the switching circuit 46
2 to notify the system abnormality.

However, the system check operation is not always performed immediately after the power is turned on, and the power switch 4 is turned on when the vehicle speed judging circuit 3 for taking in the vehicle speed signal detects that the vehicle is not moving at present. Is turned on and an ON pulse is output, the output of the AND circuit 43 activates the timer 42 for determining the opening time of the gate 44 for reading the reverberation component, and suppresses the operation of the arithmetic circuit 2 to check the system. I'm trying to get into action.

When the power is turned on, the vehicle speed determination circuit 3
When it is determined that the vehicle is moving and the output is low, the gate 44 is opened and the operation of the arithmetic circuit 2 is suppressed since the output of the AND circuit 43 does not become high even when the power is turned on. The system does not perform the system check operation, and immediately starts the obstacle detection operation.

FIG. 5 shows another example in which the same operation as described above is performed. Here, the arithmetic circuit 2 is triggered by a timing signal when the power is turned on, first executes a system check operation, and then performs an obstacle detection operation. Transition. But,
When the vehicle is already moving when an ON pulse is generated when the power switch 4 is turned on, the output of the vehicle speed determination circuit 3 is ANDed.
The output of the circuit 43 is switched, and the arithmetic circuit 2 skips the system check operation and immediately starts the obstacle detection operation.

[0015]

As described above, according to the first aspect of the present invention, the control for detecting the vehicle speed of the vehicle and stopping the obstacle detection operation when the vehicle speed is equal to or higher than a predetermined value and notifying that the detection operation is being stopped is performed. If the vehicle speed is equal to or higher than a predetermined value, the driver can accurately recognize the operation status in order to notify the user that the obstacle detection operation is not being performed.

According to a second aspect of the present invention, when a power supply is turned on, a system check operation for detecting a device abnormality is performed. The system is equipped with control means that skips the system check operation and enters the obstacle detection operation.If the vehicle is already moving when the power is turned on, the obstacle detection operation is given priority over the system check operation. In addition, there is no occurrence of a situation in which an alarm is not output despite the presence of an obstacle, and therefore, a situation in which a vehicle is hit without noticing an obstacle is not caused.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram of an example of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an obstacle detection operation according to the first embodiment;

FIG. 3 is a block circuit diagram illustrating an example of another embodiment;

FIG. 4 is an explanatory diagram of a system check operation.

FIG. 5 is a block circuit diagram of another example of the above.

[Explanation of symbols]

 1 microphone 2 arithmetic circuit 3 vehicle speed judgment circuit

Claims (2)

[Claims] 1. An ultrasonic obstacle detecting device for a vehicle, which detects an obstacle based on an output of an ultrasonic sensor for detecting a reflected wave of a transmitted ultrasonic signal, detects a vehicle speed of the vehicle, and detects a vehicle speed. An ultrasonic obstacle detecting device for a vehicle, comprising: control means for stopping an obstacle detecting operation at a vehicle speed and for notifying that the detecting operation is stopped. 2. An ultrasonic obstacle for a vehicle, which detects an obstacle by an output of an ultrasonic sensor for detecting a reflected wave of the transmitted ultrasonic signal, and performs a system check operation for detecting a device abnormality when the power is turned on. The object detection device includes a control unit that detects a vehicle speed of the vehicle at the time when the power is turned on, and skips a system check operation and enters an obstacle detection operation when the vehicle speed is equal to or higher than a predetermined value. Ultrasonic obstacle detection device for vehicles.