JP7368252B2 - object detection device - Google Patents

Description

The present invention relates to an object detection device.

2. Description of the Related Art Object detection devices that use ultrasonic sensors to detect objects around a vehicle are known. As an object detection device, there is a known object detection device that determines that snow has adhered to an ultrasonic sensor when the temporal length of reverberation waves of the ultrasonic sensor (hereinafter referred to as "reverberation time") is longer than a predetermined time. (For example, see Patent Document 1).

Further, similar to the case where snow adheres to the ultrasonic sensor, the reverberation time becomes longer when there is an object such as a wall in the vicinity of the ultrasonic sensor. On the other hand, when multiple ultrasonic sensors are installed in a vehicle, if snow adheres to one ultrasonic sensor, the other ultrasonic sensors receive the ultrasonic waves emitted from that one ultrasonic sensor. Although this is not the case, when an object is present near one ultrasonic sensor, the other ultrasonic sensors receive the ultrasonic waves emitted from one ultrasonic sensor. Therefore, when the reverberation time of one ultrasonic sensor is longer than a predetermined time, one ultrasonic sensor is There is also known an object detection device that determines whether snow has adhered to a sonic sensor or whether an object is present near one ultrasonic sensor (for example, see Patent Document 1).

Japanese Patent Application Publication No. 2011-215002

Part of the snow attached to one ultrasonic sensor melts, creating a gap between the ultrasonic sensor and the snow, and opening the side of the other ultrasonic sensor to form snow attached to the vehicle. Sometimes. In this case, the reverberation time of that one ultrasonic sensor becomes long, and other ultrasonic sensors may receive the ultrasonic waves emitted from that one ultrasonic sensor. At this time, as mentioned above, if it is determined that an object exists in the vicinity of one ultrasonic sensor, there is a possibility that the determination is incorrect, and one ultrasonic sensor may be covered with a gap. Moreover, it cannot be determined that there is snow adhering to the vehicle by opening the side of the other ultrasonic sensor.

The present invention has been made to address the above-mentioned problems. That is, one of the objects of the present invention is to cover one ultrasonic sensor with a gap and open the side of the other ultrasonic sensor to more accurately determine whether or not there is snow attached to a vehicle. The object of the present invention is to provide an object detection device that can make a determination.

An object detection device according to the present invention includes at least two ultrasonic sensors that emit ultrasonic waves and receive reflected waves of the emitted ultrasonic waves, and the at least two ultrasonic sensors are installed at different positions on a vehicle. Equipped with The object detection device according to the present invention detects objects existing around the vehicle based on information regarding the ultrasonic waves and their reflected waves transmitted by the ultrasonic sensors.

In the object detection device according to the present invention, the reverberation time, which is the time during which one of the ultrasonic sensors continues to detect vibrations of the ultrasonic wave from the time when the ultrasonic sensor emits the ultrasonic wave, is longer than a predetermined time, and the ultrasonic sensor Vehicle travel, which is the distance traveled by the vehicle from the time when the drive device of the vehicle was started when a predetermined condition that the other one of the sensors is receiving the ultrasonic waves emitted by the one ultrasonic sensor is satisfied. If the distance is a predetermined distance or more, there is partial interception snow that is snow that adheres to the vehicle in such a way that it covers the one ultrasonic sensor with a gap and opens the side of the other ultrasonic sensor. Then, it is configured to make a determination.

If snow adheres to a vehicle that covers one ultrasonic sensor with a gap and leaves the other ultrasonic sensor side open, the reverberation time of one ultrasonic sensor will be longer, and The other ultrasonic sensor receives the ultrasonic waves emitted by the other ultrasonic sensor. On the other hand, when an object such as a wall is located close to one ultrasonic sensor, the reverberation time of one ultrasonic sensor becomes longer, and the ultrasonic waves emitted by one ultrasonic sensor become Received by sensor.

Therefore, if the reverberation time is longer than a predetermined time and the other ultrasonic sensor is receiving the ultrasonic waves emitted by one ultrasonic sensor, if one ultrasonic sensor is covered with a gap and the other ultrasonic sensor is If it is determined that there is snow adhering to the vehicle by opening the sensor side (partially blocking snow) , the determination may be incorrect.

On the other hand, even if there is an object close to one ultrasonic sensor, once the vehicle starts driving and has traveled a certain distance, the vehicle will move away from the object. The object ceases to exist. Therefore, at this time, the other ultrasonic sensor no longer receives the ultrasonic waves transmitted by one ultrasonic sensor.

The object detection device according to the present invention detects a vehicle when a predetermined condition is satisfied that the reverberation time is longer than a predetermined time and the ultrasonic sensor emitted by one ultrasonic sensor is received by the other ultrasonic sensor. If the vehicle travel distance, which is the distance traveled by the vehicle from the time the drive device was started , is equal to or greater than a predetermined distance, partial blocking snow ( covering one ultrasonic sensor with a gap and covering the side of the other ultrasonic sensor) It is determined that snow adhering to the vehicle is present. Therefore, the object detection device according to the present invention can more accurately determine the presence of partially obstructing snow .

In the object detection device according to the present invention, if the vehicle traveling distance is shorter than the predetermined distance when the predetermined condition is satisfied, the partial blocking snow is not present and the object detection device is close to the one ultrasonic sensor. It may also be configured to determine that an object is present.

When an object exists near one ultrasonic sensor, the reverberation time of one ultrasonic sensor is longer than a predetermined time, and the other ultrasonic sensor receives the ultrasonic waves emitted by one ultrasonic sensor. The vehicle travel distance, which is the distance traveled by the vehicle from the time when the vehicle's drive device was started when the predetermined condition that the vehicle is present, is satisfied, is short. The object detection device according to the present invention detects a vehicle when a predetermined condition is satisfied that the reverberation time is longer than a predetermined time and the ultrasonic sensor emitted by one ultrasonic sensor is received by the other ultrasonic sensor. If the vehicle travel distance, which is the distance the vehicle has traveled since the drive device was started, is shorter than a predetermined distance, it is determined that an object exists near one of the ultrasonic sensors. Therefore, the object detection device according to the present invention can more accurately determine the presence of an object in the vicinity of one of the ultrasonic sensors.

Further, in the object detection device according to the present invention, when the reverberation time is equal to or longer than the predetermined time and the other ultrasonic sensor is not receiving the ultrasonic waves emitted by the one ultrasonic sensor, the one ultrasonic sensor It may be configured to determine that there is total blocking snow that covers the ultrasonic sensor without any gaps.

When full-blocking snow is present, the reverberation time of one ultrasonic sensor becomes longer, but the ultrasonic waves emitted by one ultrasonic sensor do not reach the other ultrasonic sensor. The object detection device according to the present invention determines that full-blocking snow exists if the reverberation time is longer than a predetermined time and the other ultrasonic sensor does not receive the ultrasonic waves transmitted by one ultrasonic sensor. Therefore, the object detection device according to the present invention can more accurately determine the presence of all-blocking snow .

Further, in the object detection device according to the present invention, when the predetermined condition is satisfied after determining that the full-blocking snow exists , the vehicle travel distance at the time when the predetermined condition is satisfied is shorter than the predetermined distance. It may also be configured to determine that the partially blocking snow is present.

Partial interception snow is likely to be formed by melting of total interception snow . The object detection device according to the present invention determines that the reverberation time is longer than a predetermined time and that the other ultrasonic sensor is receiving the ultrasonic waves emitted by one ultrasonic sensor after determining that there is full-blocking snow. If the predetermined condition is met, it is determined that partially blocking snow exists even if the vehicle travel distance at the time the predetermined condition is met is shorter than the predetermined distance. Therefore, the object detection device according to the present invention can more accurately determine the presence of partially obstructing snow .

Further , each of the ultrasonic sensors is, for example, attached to the vehicle so as to be exposed to the outside of the vehicle so as to transmit ultrasonic waves toward the outside of the vehicle. Further, the ultrasonic sensors are each attached to the vehicle so as to emit ultrasonic waves in the same direction, for example.

The components of the present invention are not limited to the embodiments of the present invention described below with reference to the drawings. Other objects, other features, and attendant advantages of the invention will be readily apparent from the description of embodiments of the invention.

FIG. 1 is a diagram showing an object detection device according to an embodiment of the present invention and a vehicle to which the object detection device is applied. FIG. 2 is a diagram showing a first ultrasonic sensor and a second ultrasonic sensor attached to a vehicle. FIG. 3 is a diagram for explaining the propagation of ultrasonic waves emitted by the first ultrasonic sensor. FIG. 4 is a diagram showing the output signal of the first ultrasonic sensor. FIG. 5 is a diagram showing the output signal of the second ultrasonic sensor. (A) of FIG. 6 is a diagram showing snow adhering to the receiving and transmitting part of the first ultrasonic sensor, and (B) of FIG. 6 is a diagram showing the receiving and transmitting part of the first ultrasonic sensor with a gap between FIG. 3 is a diagram showing snow adhering to a vehicle with the front cover open and the second ultrasonic sensor side open. FIG. 7 shows a diagram in which the receiving and transmitting parts of the first ultrasonic sensor are covered with a gap and the second ultrasonic sensor side is opened so that the first ultrasonic sensor transmits signals when there is snow attached to the vehicle. FIG. 3 is a diagram for explaining the propagation of ultrasonic waves. FIG. 8 is a diagram for explaining the propagation of ultrasonic waves emitted by the first ultrasonic sensor when an object is present in the vicinity of the receiving and transmitting section of the first ultrasonic sensor. (A) in FIG. 9 shows a case in which snow does not adhere to the transmitter/receiver part of the first ultrasonic sensor, the transmitter/receiver part of the first ultrasonic sensor is covered with a gap, and the side of the second ultrasonic sensor is open. 9 is a diagram showing the output signal of the first ultrasonic sensor when there is no snow adhering to the vehicle and there is no object close to the receiving and transmitting part of the first ultrasonic sensor, (B) shows how the first ultrasonic sensor operates when there is snow adhering to the vehicle by covering the receiving and transmitting part of the first ultrasonic sensor with a gap and leaving the second ultrasonic sensor side open. It is a figure showing an output signal. FIG. 10 shows the output of the first ultrasonic sensor when there is snow adhering to the vehicle by covering the receiving and transmitting part of the first ultrasonic sensor with a gap and leaving the second ultrasonic sensor side open. It is a diagram showing a signal. FIG. 11 is a flowchart showing a routine executed by the ECU of the object detection device according to the embodiment of the present invention. FIG. 12 is a flowchart showing a routine executed by the ECU of the object detection device according to the embodiment of the present invention. FIG. 13 is a flowchart showing a routine executed by the ECU of the object detection device according to a modification of the embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An object detection device according to an embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, an object detection device 10 according to an embodiment of the present invention is mounted on a vehicle 100. The vehicle 100 is also equipped with a drive device 20 and a brake device 30.

The drive device 20 generates torque (hereinafter referred to as "vehicle drive torque") that is applied to the drive wheels of the vehicle 100 in order to cause the vehicle 100 to travel. In this example, the drive device 20 is an internal combustion engine, but it may also be a motor, or an internal combustion engine and a motor. Braking device 30 generates a braking force to be applied to the wheels of vehicle 100 in order to brake vehicle 100 .

Furthermore, the vehicle 100 is also equipped with a control device that controls the operating states of the drive device 20, the brake device 30, and the like. The control device includes an ECU 90. The ECU 90 includes a CPU, ROM, RAM, and an interface. The object detection device 10 includes an ECU 90 as a component thereof.

As shown in FIG. 1, the drive device 20 and the brake device 30 are electrically connected to the ECU 90. The ECU 90 can control the vehicle drive torque generated by the drive device 20 by controlling the operating state of the drive device 20. Further, the ECU 90 can control the braking force generated by the braking device 30 by controlling the operating state of the braking device 30.

Furthermore, the vehicle 100 is equipped with an ignition switch 50, an accelerator pedal operation amount sensor 51, a brake pedal operation amount sensor 52, and a vehicle speed sensor 53. The ignition switch 50, the accelerator pedal operation amount sensor 51, the brake pedal operation amount sensor 52, and the vehicle speed sensor 53 are electrically connected to the ECU 90.

Ignition switch 50 is a switch operated by the driver of vehicle 100. When the ignition switch 50 is set to the on state, it transmits a signal to the ECU 90 indicating that the ignition switch 50 is set to the on state. When the ECU 90 receives the signal, the ECU 90 shifts the operating states of the drive device 20, braking device 30, etc. to a controllable state. That is, the ECU 90 substantially starts the drive device 20, the brake device 30, and the like. For example, if the drive device 20 is an internal combustion engine, the ECU 90 starts the internal combustion engine upon receiving a signal indicating that the ignition switch 50 is set to the on state.

On the other hand, when the ignition switch 50 is set to the off state, it transmits a signal to the ECU 90 indicating that the ignition switch 50 is set to the off state. When the ECU 90 receives the signal, the ECU 90 shifts the drive device 20, braking device 30, etc. to a non-operating state. That is, the ECU 90 stops the operation of the drive device 20, braking device 30, and the like. For example, when the drive device 20 is an internal combustion engine, the ECU 90 stops the operation of the internal combustion engine upon receiving a signal indicating that the ignition switch 50 is set to the OFF state.

Accelerator pedal operation amount sensor 51 detects the operation amount of accelerator pedal 21 of vehicle 100 and transmits a signal representing the detected operation amount to ECU 90. Based on the signal, the ECU 90 acquires the operation amount of the accelerator pedal 21 as the accelerator pedal operation amount AP, and controls the operating state of the drive device 20 based on the acquired accelerator pedal operation amount AP.

Brake pedal operation amount sensor 52 detects the operation amount of brake pedal 31 of vehicle 100 and transmits a signal representing the detected operation amount to ECU 90. The ECU 90 acquires the operation amount of the brake pedal 31 as the brake pedal operation amount BP based on the signal, and controls the operating state of the braking device 30 based on the acquired brake pedal operation amount BP.

Vehicle speed sensor 53 detects the rotational speed of each wheel of vehicle 100, and transmits a signal representing each detected rotational speed to ECU 90. ECU 90 obtains the rotational speed of each wheel based on these signals, and obtains the running speed of vehicle 100 as vehicle speed SPD based on the obtained rotational speed.

Furthermore, the vehicle 100 is also equipped with a first ultrasonic sensor 61, a second ultrasonic sensor 62, a display 71, and a speaker 72. The first ultrasonic sensor 61, the second ultrasonic sensor 62, the display 71, and the speaker 72 are electrically connected to the ECU 90. The object detection device 10 includes a first ultrasonic sensor 61 and a second ultrasonic sensor 62 as its components.

The first ultrasonic sensor 61 includes a receiving and transmitting section 61A. The transmitting/receiving section 61A transmits and receives ultrasonic waves. As shown in FIG. 2, the first ultrasonic sensor 61 is attached to the left front end of the vehicle 100 so that it can transmit ultrasonic waves to the front of the vehicle 100 from the transmitting/receiving section 61A. As shown in FIG. 3A, when an object 200 such as an object wall exists in front of the vehicle 100, an ultrasonic wave (hereinafter referred to as "first The ultrasonic wave") reaches the object 200, is reflected by the object 200 as shown in FIG. 3(B), and is reflected by the first ultrasonic sensor 61 as shown in FIG. 3(C). The signal reaches the receiving/transmitting section 61A. The receiving and transmitting section 61A of the first ultrasonic sensor 61 receives the first ultrasonic wave that has arrived there.

In the following description, a "reflected ultrasonic wave" is an ultrasonic wave reflected by an object, etc., and a "reflected wave of a first ultrasonic wave" is a first ultrasonic wave reflected by an object, etc.

The first ultrasonic sensor 61 transmits to the ECU 90 a signal representing information regarding the emitted first ultrasonic wave and the reflected wave of the received first ultrasonic wave. ECU 90 determines whether an object exists in front of vehicle 100 based on these signals.

When the first ultrasonic sensor 61 receives the signal shown in FIG. 4A, the ECU 90 determines that an object exists in front of the vehicle 100. The output signal of the first ultrasonic sensor 61 shown in FIG. This is when the first ultrasonic sensor 61 receives the signal. The output signal of the first ultrasonic sensor 61 shown in FIG. Indicates that it has been detected.

In the following explanation, "reverberant waves" are ultrasonic vibrations detected by the receiving and transmitting section of the ultrasonic sensor due to the ultrasonic waves emitted by the ultrasonic sensor from the time the ultrasonic sensor emits the ultrasonic waves. be. In addition, "indirect waves" are the reflected waves of ultrasonic waves emitted by one ultrasonic sensor when they are reflected by an object, etc., and the reflected waves of the ultrasonic waves are detected by the other ultrasonic sensor. , "first indirect wave" is a reflected wave of the first ultrasonic wave detected by the second ultrasonic sensor 62.

If the ECU 90 determines that an object exists in front of the vehicle 100, the ECU 90 obtains the distance between the object and the vehicle 100 based on the signal received from the first ultrasonic sensor 61.

On the other hand, if the first ultrasonic sensor 61 receives the signal shown in FIG. 4B, the ECU 90 determines that there is no object in front of the vehicle 100. The output signal of the first ultrasonic sensor 61 shown in FIG. This is when the sound wave sensor 61 does not receive any sound. The output signal of the first ultrasonic sensor 61 shown in FIG. .

As shown in FIG. 1, the second ultrasonic sensor 62 includes a receiving and transmitting section 62A. The transmitting/receiving section 62A transmits and receives ultrasonic waves. As shown in FIG. 2, the second ultrasonic sensor 62 is attached to the right front end of the vehicle 100 so that it can transmit ultrasonic waves to the front of the vehicle 100 from the transmitting/receiving section 62A. When an object exists in front of the vehicle 100, similar to the first ultrasonic sensor 61, the ultrasonic wave emitted from the receiving and transmitting section 62A of the second ultrasonic sensor 62 (hereinafter referred to as "second ultrasonic wave") It reaches an object, is reflected by the object, and reaches the receiving and transmitting section 62A of the second ultrasonic sensor 62. The receiving and transmitting section 62A of the second ultrasonic sensor 62 receives the second ultrasonic wave that has arrived there.

In the following description, the "reflected wave of the second ultrasonic wave" is the second ultrasonic wave reflected by an object or the like.

The second ultrasonic sensor 62 transmits a signal representing information regarding the emitted second ultrasonic wave and the reflected wave of the received second ultrasonic wave to the ECU 90. ECU 90 determines whether an object exists in front of vehicle 100 based on these signals.

When the second ultrasonic sensor 62 receives the signal shown in FIG. 5A, the ECU 90 determines that an object exists in front of the vehicle 100. The output signal of the second ultrasonic sensor 62 shown in FIG. This is when the second ultrasonic sensor 62 receives the signal. The output signal of the second ultrasonic sensor 62 shown in (A) of FIG. This indicates that ultrasonic vibration (that is, the reflected wave of the second ultrasonic wave) was detected until t53.

In the following description, a "second indirect wave" is a reflected wave of the second ultrasonic wave detected by the first ultrasonic sensor 61.

When ECU 90 determines that an object exists in front of vehicle 100, it obtains the distance between the object and vehicle 100 based on the signal received from second ultrasonic sensor 62.

On the other hand, if the second ultrasonic sensor 62 receives the signal shown in FIG. 5(B), the ECU 90 determines that there is no object in front of the vehicle 100. The output signal of the second ultrasonic sensor 62 shown in FIG. This is when the sound wave sensor 62 does not receive any sound. The output signal of the second ultrasonic sensor 62 shown in FIG. .

The display 71 displays images according to various command signals transmitted from the ECU 90.

The speaker 72 outputs sounds according to various command signals transmitted from the ECU 90.

<Overview of operation>
Next, an overview of the operations of the object detection device 10 and the ECU 90 of the control device will be described.

The ECU 90 determines whether an object exists in front of the vehicle 100 using the output signals of the first ultrasonic sensor 61 and the second ultrasonic sensor 62, and when it is determined that an object exists in front of the vehicle 100. , execute contact avoidance control.

More specifically, if the ECU 90 determines that an object exists in front of the vehicle 100, it starts contact avoidance control and obtains the distance Dobj between the object that exists in front of the vehicle 100 and the vehicle 100. The ECU 90 obtains the time TTC required for the vehicle 100 to reach the object as the predicted arrival time TTC based on the obtained distance Dobj and the vehicle speed SPD at that time.

When the acquired predicted arrival time TTC becomes less than or equal to a predetermined first time TTC1, the ECU 90 causes the display 71 to display an image indicating that the vehicle 100 is approaching the object, and also displays an image indicating that the vehicle 100 is approaching the object. The speaker 72 outputs a warning sound indicating that the user is present.

Thereafter, when the predicted arrival time TTC becomes equal to or less than a predetermined second time TTC2, which is shorter than the first time TTC1, the ECU 90 sets the vehicle drive torque to zero by controlling the operation of the drive device 20, and also controls the braking device 30. By controlling the operation of the vehicle 100, the vehicle 100 is braked to stop the vehicle 100, thereby preventing the vehicle 100 from coming into contact with an object.

Note that when the predicted arrival time TTC becomes less than or equal to the second time TTC2, the ECU 90 controls the operation of the power steering device (not shown) of the vehicle 100 in addition to or in place of controlling the operation of the drive device 20 and the braking device 30 described above. It may be configured to steer the vehicle 100 so that the vehicle 100 does not come into contact with an object by controlling the operation.

By the way, as shown in FIG. 6A, when it snows, for example, while the ignition switch 50 is turned off and the vehicle 100 is stopped, the receiving and transmitting part 61A of the first ultrasonic sensor 61 is exposed to snow. 301 may adhere. In this case, even if the first ultrasonic sensor 61 emits ultrasonic waves, the ultrasonic waves do not propagate beyond the snow 301. That is, the propagation of the ultrasonic waves emitted from the first ultrasonic sensor 61 is blocked by the snow 301.

In the following description, snow that adheres to the receiving and transmitting section of the ultrasonic sensor so as to cover the entire receiving and transmitting section will be referred to as "total blocking snow." Total blocking snow is snow that blocks the propagation of ultrasonic waves emitted from an ultrasonic sensor over a certain distance.

Thereafter, when the ignition switch 50 is turned on and a certain period of time has elapsed, the part of the full-blocking snow 301 in contact with the receiving and transmitting section 61A of the first ultrasonic sensor 61 and the full-blocking snow on the side of the second ultrasonic sensor 62 are removed. Part 301 may melt. In this case, as shown in FIG. 6(B), the full blocking snow 301 has a gap between it and the receiving and transmitting section 61A of the first ultrasonic sensor 61 and the receiving and transmitting section of the first ultrasonic sensor 61. The snow 302 has a hole that exposes 61A. That is, the snow 302 is snow that adheres to the vehicle 100 so as to cover the transmitter/receiver section 61A of the first ultrasonic sensor 61 with a gap and leave the second ultrasonic sensor 62 side open.

When such snow 302 occurs, the first ultrasonic wave (that is, the ultrasonic wave emitted from the first ultrasonic sensor 61) immediately after being emitted falls onto the snow 302, as shown in FIG. 7(A). As shown in FIG. reach.

In the following description, snow that adheres to a vehicle in such a way that it covers the receiving and transmitting part of an ultrasonic sensor with a gap and leaves the side of another ultrasonic sensor open will be referred to as "partially blocking snow." Partially blocking snow is snow that exists in front of the receiver and transmitter of an ultrasonic sensor (i.e., in the direction in which the receiver and transmitter transmits ultrasonic waves) with a gap from the receiver and transmitter, and the ultrasonic waves reflected by the snow are This is snow that does not prevent reflected waves of sound waves from reaching the receiving and transmitting parts of other ultrasonic sensors. In addition, partial blocking snow blocks the propagation of ultrasonic waves emitted from an ultrasonic sensor over a certain distance in the desired direction, but does not block the propagation of reflected waves of the ultrasonic waves to other ultrasonic sensors. It's snow.

When there is snow that partially blocks the reception/transmission section 61A of the first ultrasonic sensor 61, the first ultrasonic sensor 61 and the second ultrasonic sensor 62 output the signals shown in FIG. 8 to the ECU 90. The output signal of the first ultrasonic sensor 61 shown in FIG. This indicates that ultrasonic vibrations were detected up to t81. Further, the output signal of the second ultrasonic sensor 62 shown in FIG. This indicates that ultrasonic vibrations were detected from time t83 to time t83.

(1) There is no full blocking snow adhering to the receiving and transmitting section 61A of the first ultrasonic sensor 61, and (2) there is no partial blocking snow near the receiving and transmitting section 61A of the first ultrasonic sensor 61, and (3) ) When there is no object close to the receiving/transmitting section 61A of the first ultrasonic sensor 61, the first ultrasonic sensor 61 outputs the signal shown in FIG. 9(A). The output signal of the first ultrasonic sensor 61 shown in FIG. is output. The output signal of the first ultrasonic sensor 61 shown in FIG. ing.

Hereinafter, the time during which the first ultrasonic sensor 61 continues to detect ultrasonic vibrations from the time when the first ultrasonic sensor 61 emits ultrasonic waves will be referred to as "first reverberation time Tz_1."

On the other hand, when there is partially blocking snow near the receiving/transmitting section 61A of the first ultrasonic sensor 61, the first ultrasonic sensor 61 outputs the signal shown in FIG. 9(B). The output signal of the first ultrasonic sensor 61 shown in FIG. The output is continued until time t92. The output signal of the first ultrasonic sensor 61 shown in FIG. 9(B) indicates that the first ultrasonic sensor 61 continuously detects ultrasonic vibration from time t90 to time t92.

When there is snow that partially blocks the transmitting/receiving section 61A of the first ultrasonic sensor 61, the first ultrasonic sensor 61 will not be able to transmit the ultrasonic waves for a certain period of time after transmitting the ultrasonic waves. The ultrasonic vibrations (i.e., reverberant waves) that occur are detected, but after a certain period of time has elapsed since the ultrasonic waves were emitted, they are reflected by the partially blocked snow that exists near the receiving and transmitting section 61A of the first ultrasonic sensor 61. Then, the vibration of the reflected wave of the first ultrasonic wave reaching the first ultrasonic sensor 61 is detected.

Therefore, the output signal shown in (B) of FIG. The first ultrasonic sensor 61 detects the vibration of the reflected wave of the first ultrasonic wave that is reflected by the partially blocked snow that is present in the vicinity of the receiving and transmitting unit 61A and reaches the first ultrasonic sensor 61. represents.

Therefore, when there is partial blocking snow near the receiving/transmitting section 61A of the first ultrasonic sensor 61, there is no partially blocking snow near the receiving/transmitting section 61A of the first ultrasonic sensor 61, and the first ultrasonic wave is The first reverberation time Tz_1 is longer than when the sensor 61 is not completely covered with snow and there is no object close to the first ultrasonic sensor 61.

Further, when there is partially blocking snow near the receiving and transmitting section 61A of the first ultrasonic sensor 61, the second ultrasonic sensor 62 outputs the signal shown in FIG. 8 to the ECU 90. The output signal of the second ultrasonic sensor 62 shown in FIG. 8 is when the first ultrasonic sensor 61 transmits an ultrasonic wave at time t80, and is from time t82 to time t83, which is after time t80. Continuous output. The output signal of the second ultrasonic sensor 62 shown in FIG. 2 indicates that the ultrasonic sensor 62 continuously detects from time t82 to time t83.

Note that the ECU 90 determines whether the ultrasonic waves received by the second ultrasonic sensor 62 are the first or It is possible to determine whether the wave is a reflected wave of an ultrasonic wave.

From the above, when the first reverberation time Tz_1 is longer than the predetermined time Tz_th and the second ultrasonic sensor 62 is receiving the reflected wave of the first ultrasonic wave, the receiving and transmitting section 61A of the first ultrasonic sensor 61 It is also conceivable to determine that there is partially blocking snow in the vicinity of .

However, as shown in FIG. 10, even if there is an object 200 such as a wall in the vicinity of the receiving and transmitting section 61A of the first ultrasonic sensor 61, the first reverberation time Tz_1 is equal to or longer than the predetermined time Tz_th, and The second ultrasonic sensor 62 may receive the reflected wave of the first ultrasonic wave.

That is, when the object 200 is present in the vicinity of the receiving and transmitting section 61A of the first ultrasonic sensor 61, immediately after being emitted, the first ultrasonic wave is transmitted to the object 200 as shown in FIG. 10(A). and as shown in FIG. 10(B), it is reflected by the object 200 and reaches the first ultrasonic sensor 61 and the second ultrasonic sensor 62. Therefore, the first reverberation time Tz_1 is longer than the predetermined time Tz_th, and the receiving and transmitting unit 62A of the second ultrasonic sensor 62 receives the reflected wave of the first ultrasonic wave.

Therefore, when the first reverberation time Tz_1 is longer than the predetermined time Tz_th and the second ultrasonic sensor 62 is receiving the reflected wave of the first ultrasonic wave, the ultrasonic sensor 61 approaches the receiving and transmitting section 61A of the first ultrasonic sensor 61. If it is determined that there is partially blocking snow, there is a possibility that the determination is incorrect.

On the other hand, even if an object is present in the vicinity of the receiving and transmitting section 61A of the first ultrasonic sensor 61, once the vehicle 100 starts traveling and travels a certain distance, the vehicle 100 will move away from the object. Objects close to the ultrasonic sensor 61 no longer exist. Therefore, at this time, the second ultrasonic sensor 62 no longer receives the reflected wave of the first ultrasonic wave.

Therefore, the ECU 90 switches the ignition switch 50 when the first condition that the first reverberation time Tz_1 is longer than the predetermined time Tz_th and the second ultrasonic sensor 62 is receiving the reflected wave of the first ultrasonic wave is satisfied. It is determined whether the vehicle travel distance D from the time when is turned on is greater than or equal to a predetermined distance Dth.

Alternatively, if the first condition that the first reverberation time Tz_1 is longer than the predetermined time Tz_th and the second ultrasonic sensor 62 is receiving the reflected wave of the first ultrasonic wave is satisfied, the ECU 90 satisfies the first condition. It is determined whether the vehicle travel distance D from the time when is established is greater than or equal to a predetermined distance Dth.

That is, when the first condition that the first reverberation time Tz_1 is longer than the predetermined time Tz_th and the second ultrasonic sensor 62 is receiving the reflected wave of the first ultrasonic wave is satisfied, the ECU 90 determines that the first reverberation time Tz_1 is at least the first ultrasonic wave. It is determined whether the vehicle travel distance D from the time when the condition is met is greater than or equal to a predetermined distance Dth.

In this example, the predetermined time Tz_th is determined when (1) snow does not adhere to the transmitter/receiver section 61A of the first ultrasonic sensor 61 and (2) the transmitter/receiver section 61A of the first ultrasonic sensor 61 is close to the transmitter/receiver section 61A. When there is no partial interception snow and (3) there is no object close to the receiving and transmitting section 61A of the first ultrasonic sensor 61, the ultrasonic wave continues from the time when the first ultrasonic sensor 61 transmits the ultrasonic wave. Set to the time to detect vibrations.

Further, in this example, the predetermined distance Dth is such that the second ultrasonic sensor 62, which had been receiving the reflected wave of the first ultrasonic wave reflected by the object, no longer receives the reflected wave of the first ultrasonic wave reflected by the object. The travel distance of vehicle 100 is set to the travel distance of vehicle 100 when vehicle 100 travels sufficiently far away from the object.

Furthermore, in this example, the vehicle travel distance D is the distance traveled by the vehicle 100 in the direction opposite to the direction in which the first ultrasonic sensor 61 emits ultrasonic waves. However, the vehicle travel distance D may be the distance traveled by the vehicle 100 in the forward direction, or may be the sum of the distance traveled by the vehicle 100 in the forward direction and the distance traveled by the vehicle 100 in the backward direction. good. Furthermore, when the first ultrasonic sensor 61 emits ultrasonic waves in the forward direction of the vehicle 100, the distance may be the distance that the vehicle 100 has traveled in the backward direction minus the distance that the vehicle 100 has traveled in the forward direction. When the first ultrasonic sensor 61 emits ultrasonic waves in the backward direction of the vehicle 100, the distance may be the distance that the vehicle 100 has traveled in the forward direction minus the distance that the vehicle 100 has traveled in the backward direction.

If the vehicle travel distance D is shorter than the predetermined distance Dth, the ECU 90 determines that an object exists in the vicinity of the transmitter/receiver section 61A of the first ultrasonic sensor 61. On the other hand, if the vehicle travel distance D is equal to or greater than the predetermined distance Dth, the ECU 90 determines that there is partially blocking snow in the vicinity of the receiving/transmitting section 61A of the first ultrasonic sensor 61.

Thereby, it is possible to accurately determine whether or not there is partially blocking snow in the vicinity of the transmitting/receiving section 61A of the first ultrasonic sensor 61.

Furthermore, even when full-blocking snow is attached to the receiving and transmitting section 61A of the first ultrasonic sensor 61, the first reverberation time Tz_1 is equal to or longer than the predetermined time Tz_th. However, since the total blocking snow has adhered to the receiving and transmitting section 61A of the first ultrasonic sensor 61, the reflected wave of the first ultrasonic wave does not reach the second ultrasonic sensor 62.

Therefore, when the first reverberation time Tz_1 is equal to or longer than the predetermined time Tz_th and the second ultrasonic sensor 62 does not receive the reflected wave of the first ultrasonic wave, the ECU 90 controls the transmitter/receiver section 61A of the first ultrasonic sensor 61. It is determined that all interception snow is attached to the area.

The ECU 90 also performs the same determination as the first ultrasonic sensor 61 regarding the second ultrasonic sensor 62. That is, the ECU 90 switches the ignition switch 50 when the second condition that the second reverberation time Tz_2 is longer than the predetermined time Tz_th and the first ultrasonic sensor 61 is receiving the reflected wave of the second ultrasonic wave is satisfied. It is determined whether the vehicle travel distance D from the time when is turned on is greater than or equal to a predetermined distance Dth.

Alternatively, if the second condition that the second reverberation time Tz_2 is equal to or longer than the predetermined time Tz_th and the first ultrasonic sensor 61 receives the reflected wave of the second ultrasonic wave is satisfied, the ECU 90 satisfies the second condition. It is determined whether the vehicle travel distance D from the time when is established is greater than or equal to a predetermined distance Dth.

That is, when the second condition that the second reverberation time Tz_2 is longer than the predetermined time Tz_th and the first ultrasonic sensor 61 receives the reflected wave of the second ultrasonic wave is satisfied, the ECU 90 reverberates the second reverberation time at the latest. It is determined whether the vehicle travel distance D from the time when the condition is met is greater than or equal to a predetermined distance Dth.

Note that the "second reverberation time Tz_2" is the time during which the second ultrasonic sensor 62 continues to detect ultrasonic vibrations from the time when the second ultrasonic sensor 62 emits ultrasonic waves.

If the vehicle travel distance D is shorter than the predetermined distance Dth, the ECU 90 determines that an object is present in the vicinity of the transmitting/receiving section 62A of the second ultrasonic sensor 62. On the other hand, when the vehicle travel distance D is equal to or greater than the predetermined distance Dth, the ECU 90 determines that there is partially blocking snow in the vicinity of the receiving/transmitting section 62A of the second ultrasonic sensor 62.

Thereby, it is possible to more accurately determine whether or not there is partially blocking snow in the vicinity of the receiving/transmitting section 62A of the second ultrasonic sensor 62.

Further, when the second reverberation time Tz_2 is equal to or longer than the predetermined time Tz_th and the first ultrasonic sensor 61 does not receive the reflected wave of the second ultrasonic wave, the ECU 90 controls the transmitter/receiver section 62A of the second ultrasonic sensor 62. It is determined that all interception snow is attached to the area.

<Specific operation>
Next, specific operations of the object detection device 10 and the ECU 90 of the control device will be described. The ECU 90 of the object detection device 10 is configured to execute the routine shown in FIG. 11 every predetermined time period. Further, the ECU 90 alternately executes the routine shown in FIG. 11 for the first ultrasonic sensor 61 and the routine shown in FIG. 11 for the second ultrasonic sensor 62.

When the routine shown in FIG. 11 is executed for the first ultrasonic sensor 61 at a predetermined timing, the ECU 90 starts the process from step 1100, advances the process to step 1105, and sets the first reverberation time Tz_1. It is determined whether or not is longer than a predetermined time Tz_th.

When the ECU 90 determines "Yes" in step 1105, the process proceeds to step 1110, and determines whether the value of the first indirect wave flag Xk_1 is "1". The value of the first indirect wave flag Xk_1 is set to "1" when the second ultrasonic sensor 62 is receiving the first indirect wave, and when the second ultrasonic sensor 62 is not receiving the first indirect wave. If not, it is set to "0".

If the ECU 90 determines "Yes" in step 1110, the process proceeds to step 1115 and determines whether the vehicle travel distance D is equal to or greater than a predetermined distance Dth.

When the ECU 90 determines "Yes" in step 1115, the process proceeds to step 1120 and sets the value of the first snow flag Xs_1 to "1". In this case, the ECU 90 has determined that there is partially blocking snow in the vicinity of the transmitting/receiving section 61A of the first ultrasonic sensor 61. Thereafter, the ECU 90 advances the process to step 1195 and temporarily ends this routine.

On the other hand, if the ECU 90 determines "No" in step 1115, the process proceeds to step 1125 and sets the value of the first snow flag Xs_1 to "0". In this case, the ECU 90 has determined that an object is present in the vicinity of the transmitting/receiving section 61A of the first ultrasonic sensor 61. Thereafter, the ECU 90 advances the process to step 1195 and temporarily ends this routine.

When the ECU 90 determines "No" in step 1110, the process proceeds to step 1130 and sets the value of the first snow flag Xs_1 to "1". In this case, the ECU 90 determines that all-blocking snow is attached to the receiving and transmitting section 61A of the first ultrasonic sensor 61. Thereafter, the ECU 90 advances the process to step 1195 and temporarily ends this routine.

When the ECU 90 determines "No" in step 1105, the process proceeds to step 1135 and sets the value of the first snow flag Xs_1 to "0". In this case, the ECU 90 determines that (1) there is no partial blocking snow near the receiving/transmitting section 61A of the first ultrasonic sensor 61, and (2) there is no full blocking snow adhering to the receiving/transmitting section 61A of the first ultrasonic sensor 61. (3) It is determined that there is no object close to the receiving/transmitting section 61A of the first ultrasonic sensor 61. Thereafter, the ECU 90 advances the process to step 1195 and temporarily ends this routine.

Thereafter, at a predetermined timing, the ECU 90 executes the routine shown in FIG. 11. At this time, the ECU 90 executes the routine shown in FIG. 11 for the second ultrasonic sensor 62. In this case, the ECU 90 determines in step 1105 whether the second reverberation time Tz_2 is equal to or longer than the predetermined time Tz_th. Further, the ECU 90 determines in step 1110 whether the value of the second indirect wave flag Xk_2 is "1". The value of the second indirect wave flag Xk_2 is set to "1" when the first ultrasonic sensor 61 is receiving the second indirect wave; If not, it is set to "0".

Further, the ECU 90 determines in step 1115 whether the vehicle travel distance D is equal to or greater than a predetermined distance Dth. Further, when the ECU 90 advances the process to step 1120, the ECU 90 sets the value of the second snow flag Xs_2 to "1". In this case, the ECU 90 has determined that there is partially blocking snow in the vicinity of the receiving/transmitting section 62A of the second ultrasonic sensor 62.

Further, when the ECU 90 advances the process to step 1125, the ECU 90 sets the value of the second snow flag Xs_2 to "0". In this case, the ECU 90 has determined that an object exists in the vicinity of the receiving/transmitting section 62A of the second ultrasonic sensor 62.

Further, when the ECU 90 advances the process to step 1130, the ECU 90 sets the value of the second snow flag Xs_2 to "1". In this case, the ECU 90 determines that all-blocking snow is attached to the receiving and transmitting section 62A of the second ultrasonic sensor 62.

Further, when the ECU 90 advances the process to step 1135, the ECU 90 sets the value of the second snow flag Xs_2 to "0". In this case, the ECU 90 determines that (1) there is no partial blocking snow near the receiving/transmitting section 62A of the second ultrasonic sensor 62, and (2) there is no full blocking snow adhering to the receiving/transmitting section 62A of the second ultrasonic sensor 62. (3) It is determined that there is no object close to the receiving/transmitting section 62A of the second ultrasonic sensor 62.

Further, the ECU 90 is configured to execute the routine shown in FIG. 12 every predetermined time period. Therefore, at a predetermined timing, the ECU 90 starts the process from step 1200 in FIG. 12 and advances the process to step 1205, so that both the value of the first snow flag ”.

When the ECU 90 determines "Yes" in step 1205, the process proceeds to step 1210, and executes control non-operation notification processing to notify the driver that contact avoidance control is not being performed. Specifically, the ECU 90 causes the display 71 to display an image indicating that contact avoidance control is not being executed. Thereafter, the ECU 90 advances the process to step 1295 and temporarily ends this routine.

On the other hand, if the ECU 90 determines "No" in step 1205, the process proceeds to step 1215 and acquires the predicted arrival time TTC. Next, the ECU 90 advances the process to step 1220 and determines whether the predicted arrival time TTC acquired in step 1215 is less than or equal to the second time TTC2.

When the ECU 90 determines "Yes" in step 1220, the process proceeds to step 1225, and executes torque reduction processing and braking processing. The torque reduction process is a process in which the drive torque output from the drive device 20 is set to zero, and the braking process is a process in which the brake device 30 brakes the vehicle 100 to stop the vehicle 100. Thereafter, the ECU 90 advances the process to step 1295 and temporarily ends this routine.

On the other hand, if the ECU 90 determines "No" in step 1220, the process proceeds to step 1230, and determines whether the predicted arrival time TTC acquired in step 1215 is less than or equal to the first time TTC1.

When the ECU 90 determines "Yes" in step 1230, the process proceeds to step 1235 and executes an approach notification process. The approach notification process is a process in which an image indicating that the vehicle 100 is approaching an object is displayed on the display 71, and a warning sound indicating that the vehicle 100 is approaching the object is output from the speaker 72. Thereafter, the ECU 90 advances the process to step 1295 and temporarily ends this routine.

On the other hand, if the ECU 90 determines "No" in step 1230, the ECU 90 directly advances the process to step 1295 and temporarily ends this routine.

The above is the specific processing of the ECU 90. By the ECU 90 executing the routine shown in FIG. It is possible to more accurately determine whether or not there is partially blocking snow in the vicinity of 62A.

Note that the present invention is not limited to the above embodiments, and various modifications can be adopted within the scope of the present invention.

<Modified example>
By the way, there is a high possibility that partial interception snow is formed by melting a part of total interception snow. Therefore, the object detection device 10 and the ECU 90 of the control device according to a modification of the embodiment of the present invention may be configured as follows. That is, when the first reverberation time Tz_1 is equal to or longer than the predetermined time Tz_th and the second ultrasonic sensor 62 does not receive the reflected wave of the first ultrasonic wave, the ECU 90 controls the transmitter/receiver section 61A of the first ultrasonic sensor 61. It is determined that all interception snow is attached to the area.

Furthermore, the ECU 90 switches the ignition switch 50 when the first condition that the first reverberation time Tz_1 is longer than the predetermined time Tz_th and the second ultrasonic sensor 62 is receiving the reflected wave of the first ultrasonic wave is satisfied. It is determined whether the vehicle travel distance D from the time when is turned on is greater than or equal to a predetermined distance Dth.

If the vehicle travel distance D is equal to or greater than the predetermined distance Dth, the ECU 90 determines that there is partially blocking snow in the vicinity of the transmitting/receiving section 61A of the first ultrasonic sensor 61.

On the other hand, when the vehicle travel distance D is shorter than the predetermined distance Dth, the ECU 90 controls the transmission/reception section 61A of the first ultrasonic sensor 61 after the ignition switch 50 is turned on and before the first condition is satisfied. It is determined whether or not it is determined that all interception snow is attached to the area.

If the ECU 90 determines that snow has adhered to the receiving and transmitting section 61A of the first ultrasonic sensor 61 after the ignition switch 50 is turned on and before the first condition is satisfied, It is determined that there is partially blocking snow in the vicinity of the receiving and transmitting section 61A of the first ultrasonic sensor 61.

On the other hand, after the ignition switch 50 is turned on and before the first condition is satisfied, the ECU 90 does not determine that snow has adhered to the receiving and transmitting section 61A of the first ultrasonic sensor 61. In this case, it is determined that an object exists in the vicinity of the transmitting/receiving section 61A of the first ultrasonic sensor 61.

Thereby, it is possible to accurately determine whether or not there is partially blocking snow in the vicinity of the transmitting/receiving section 61A of the first ultrasonic sensor 61.

The ECU 90 also performs the same determination as the first ultrasonic sensor 61 regarding the second ultrasonic sensor 62. That is, when the second reverberation time Tz_2 is equal to or longer than the predetermined time Tz_th and the first ultrasonic sensor 61 does not receive the reflected wave of the second ultrasonic wave, the ECU 90 controls the transmitter/receiver section 62A of the second ultrasonic sensor 62. It is determined that all interception snow is attached to the area.

Further, the ECU 90 switches the ignition switch 50 when the second condition that the second reverberation time Tz_2 is longer than the predetermined time Tz_th and the first ultrasonic sensor 61 is receiving the reflected wave of the second ultrasonic wave is satisfied. It is determined whether the vehicle travel distance D from the time when is turned on is greater than or equal to a predetermined distance Dth.

If the vehicle travel distance D is equal to or greater than the predetermined distance Dth, the ECU 90 determines that there is partially blocking snow in the vicinity of the transmitting/receiving section 62A of the second ultrasonic sensor 62.

On the other hand, when the vehicle traveling distance D is shorter than the predetermined distance Dth, the ECU 90 controls the transmission/reception part 62A of the second ultrasonic sensor 62 after the ignition switch 50 is turned on and before the second condition is satisfied. It is determined whether or not it is determined that all interception snow is attached to the area.

If the ECU 90 determines that snow has adhered to the receiving and transmitting section 62A of the second ultrasonic sensor 62 after the ignition switch 50 is turned on and before the second condition is satisfied, It is determined that there is partially blocking snow near the receiving and transmitting section 62A of the second ultrasonic sensor 62.

On the other hand, after the ignition switch 50 is turned on and before the second condition is satisfied, the ECU 90 does not determine that snow has adhered to the receiving and transmitting section 62A of the second ultrasonic sensor 62. In this case, it is determined that an object exists in the vicinity of the receiving and transmitting section 62A of the second ultrasonic sensor 62.

Thereby, it is possible to accurately determine whether or not there is partially blocking snow in the vicinity of the receiving/transmitting section 62A of the second ultrasonic sensor 62.

Next, a specific operation of the ECU 90 of the object detection device 10 according to the modification will be described. The ECU 90 of the object detection device 10 according to the modification is configured to execute the routine shown in FIG. 13 every predetermined time period instead of the routine shown in FIG. 11. Further, the ECU 90 alternately executes the routine shown in FIG. 13 for the first ultrasonic sensor 61 and the routine shown in FIG. 13 for the second ultrasonic sensor 62.

When the routine shown in FIG. 13 is executed for the first ultrasonic sensor 61 at a predetermined timing, the ECU 90 starts the process from step 1300, advances the process to step 1305, and sets the first reverberation time Tz_1. It is determined whether or not is longer than a predetermined time Tz_th.

When the ECU 90 determines "Yes" in step 1305, the process proceeds to step 1310, and determines whether the value of the first indirect wave flag Xk_1 is "1". The value of the first indirect wave flag Xk_1 is set to "1" when the second ultrasonic sensor 62 is receiving the first indirect wave, and when the second ultrasonic sensor 62 is not receiving the first indirect wave. If not, it is set to "0".

If the ECU 90 determines "Yes" in step 1310, the process proceeds to step 1315 and determines whether the vehicle travel distance D is equal to or greater than a predetermined distance Dth.

When the ECU 90 determines "Yes" in step 1315, the process proceeds to step 1320, and sets the value of the first snow flag Xs_1 to "1". In this case, the ECU 90 has determined that there is partially blocking snow in the vicinity of the transmitting/receiving section 61A of the first ultrasonic sensor 61.

Next, the ECU 90 advances the process to step 1321, and sets the value of the first full-blocking snow flag Xz_1 to "0". The value of the first full-blocking snow flag Xz_1 is set to "1" when it is determined that full-blocking snow is attached to the receiving and transmitting section 61A of the first ultrasonic sensor 61. The value of the first full blocking snow flag When it is determined that an object is present in the vicinity of the transmitter/receiver section 61A of the sensor 61, and (3) when no snow adheres to the transmitter/receiver section 61A of the first ultrasonic sensor 61 and the first ultrasonic wave is It is set to "0" when it is determined that there is no partial blocking snow near the receiving and transmitting section 61A of the sensor 61 and that there is no object near the receiving and transmitting section 61A of the first ultrasonic sensor 61.

Thereafter, the ECU 90 advances the process to step 1395 and temporarily ends this routine.

On the other hand, when the ECU 90 determines "No" in step 1315, the process proceeds to step 1322, and determines whether the value of the first full-blocking snow flag Xz_1 is "1".

When the ECU 90 determines "Yes" in step 1322, the process proceeds to step 1323 and sets the value of the first snow flag Xs_1 to "1". In this case, the ECU 90 has determined that there is partially blocking snow in the vicinity of the transmitting/receiving section 61A of the first ultrasonic sensor 61.

Next, the ECU 90 advances the process to step 1324, and sets the value of the first full-blocking snow flag Xz_1 to "0". Thereafter, the ECU 90 advances the process to step 1395 and temporarily ends this routine.

On the other hand, if the ECU 90 determines "No" in step 1322, the process proceeds to step 1325 and sets the value of the first snow flag Xs_1 to "0". In this case, the ECU 90 has determined that an object is present in the vicinity of the transmitting/receiving section 61A of the first ultrasonic sensor 61.

Next, the ECU 90 advances the process to step 1326, and sets the value of the first full-blocking snow flag Xz_1 to "0". Thereafter, the ECU 90 advances the process to step 1395 and temporarily ends this routine.

If the ECU 90 determines "No" in step 1310, the ECU 90 advances the process to step 1330 and sets the value of the first snow flag Xs_1 to "1". In this case, the ECU 90 determines that all-blocking snow is attached to the receiving and transmitting section 61A of the first ultrasonic sensor 61.

Next, the ECU 90 advances the process to step 1331, and sets the value of the first full-blocking snow flag Xz_1 to "1". Thereafter, the ECU 90 advances the process to step 1395 and temporarily ends this routine.

When the ECU 90 determines "No" in step 1305, the process proceeds to step 1335 and sets the value of the first snow flag Xs_1 to "0". In this case, the ECU 90 determines that (1) there is no partial blocking snow near the receiving/transmitting section 61A of the first ultrasonic sensor 61, and (2) there is no full blocking snow adhering to the receiving/transmitting section 61A of the first ultrasonic sensor 61. (3) It is determined that there is no object close to the receiving/transmitting section 61A of the first ultrasonic sensor 61.

Next, the ECU 90 advances the process to step 1336, and sets the value of the first full-blocking snow flag Xz_1 to "0". Thereafter, the ECU 90 advances the process to step 1395 and temporarily ends this routine.

Thereafter, at a predetermined timing, the ECU 90 executes the routine shown in FIG. 13. At this time, the ECU 90 executes the routine shown in FIG. 13 for the second ultrasonic sensor 62. In this case, the ECU 90 determines in step 1305 whether the second reverberation time Tz_2 is equal to or longer than the predetermined time Tz_th. Further, the ECU 90 determines in step 1310 whether the value of the second indirect wave flag Xk_2 is "1". The value of the second indirect wave flag Xk_2 is set to "1" when the first ultrasonic sensor 61 is receiving the second indirect wave; If not, it is set to "0".

Further, the ECU 90 determines in step 1315 whether the vehicle travel distance D is equal to or greater than a predetermined distance Dth. Further, when the ECU 90 advances the process to step 1320, the ECU 90 sets the value of the second snow flag Xs_2 to "1". In this case, the ECU 90 has determined that there is partially blocking snow in the vicinity of the receiving/transmitting section 62A of the second ultrasonic sensor 62.

Further, when the ECU 90 advances the process to step 1321, the ECU 90 sets the value of the second all-blocking snow flag Xz_2 to "0". The value of the second all-blocking snow flag Xz_2 is set to "1" when it is determined that all-blocking snow is attached to the receiving and transmitting section 62A of the second ultrasonic sensor 62. Further, the value of the second full blocking snow flag Xz_2 is determined by (1) when it is determined that there is partial blocking snow in the vicinity of the receiving and transmitting section 62A of the second ultrasonic sensor 62, (2) when the second ultrasonic sensor 62 (3) When it is determined that there is an object in the vicinity of the transmitting/receiving section 62A of the second ultrasonic sensor 62, and (3) when no snow is attached to the transmitting/receiving section 62A of the second ultrasonic sensor 62, and when the second ultrasonic sensor 62 It is set to "0" when it is determined that there is no partial blocking snow near the receiving/transmitting section 62A of the second ultrasonic sensor 62 and there is no object near the receiving/transmitting section 62A of the second ultrasonic sensor 62.

Further, the ECU 90 determines in step 1322 whether or not the value of the second all-blocking snow flag Xz_2 is "1". Further, when the ECU 90 advances the process to step 1323, the ECU 90 sets the value of the second snow flag Xs_2 to "1". In this case, the ECU 90 has determined that there is partially blocking snow in the vicinity of the receiving/transmitting section 62A of the second ultrasonic sensor 62. Further, when the ECU 90 advances the process to step 1324, the ECU 90 sets the value of the second all-blocking snow flag Xz_2 to "0".

Further, when the ECU 90 advances the process to step 1325, the ECU 90 sets the value of the second snow flag Xs_2 to "0". In this case, the ECU 90 has determined that an object exists in the vicinity of the receiving/transmitting section 62A of the second ultrasonic sensor 62. Further, when the ECU 90 advances the process to step 1326, the ECU 90 sets the value of the second all-blocking snow flag Xz_2 to "0".

Further, when the ECU 90 advances the process to step 1330, the ECU 90 sets the value of the second snow flag Xs_2 to "1". In this case, the ECU 90 determines that all-blocking snow is attached to the receiving and transmitting section 62A of the second ultrasonic sensor 62. Further, when the ECU 90 advances the process to step 1331, the ECU 90 sets the value of the second full-blocking snow flag Xz_2 to "1".

Further, when the ECU 90 advances the process to step 1335, the ECU 90 sets the value of the second snow flag Xs_2 to "0". In this case, the ECU 90 determines that (1) there is no partial blocking snow near the receiving/transmitting section 62A of the second ultrasonic sensor 62, and (2) there is no full blocking snow adhering to the receiving/transmitting section 62A of the second ultrasonic sensor 62. (3) It is determined that there is no object close to the receiving/transmitting section 62A of the second ultrasonic sensor 62. Further, when the ECU 90 advances the process to step 1336, the ECU 90 sets the value of the second all-blocking snow flag Xz_2 to "0".

The above is the specific operation of the ECU 90 of the object detection device 10 according to the modification. By the ECU 90 executing the routine shown in FIG. It is possible to more accurately determine whether or not there is partially blocking snow in the vicinity of 62A.

DESCRIPTION OF SYMBOLS 10... Object detection device, 61... First ultrasonic sensor, 61A... Receiving/transmitting unit, 62... Second ultrasonic sensor, 62A... Receiving/transmitting unit, 90... ECU, 100... Vehicle, 200... Object, 301... Total cutoff Snow, 302...partially blocked snow

Claims (6)

At least two ultrasonic sensors that emit ultrasonic waves and receive reflected waves of the emitted ultrasonic waves, the at least two ultrasonic sensors installed at different positions on the vehicle,
In an object detection device that detects objects existing around the vehicle based on information regarding ultrasonic waves and reflected waves thereof transmitted by the ultrasonic sensors,
The reverberation time, which is the time during which one of the ultrasonic sensors continues to detect ultrasonic vibrations from the time when the ultrasonic waves are emitted, is longer than a predetermined time, and the other one of the ultrasonic sensors transmits the ultrasonic waves of the one ultrasonic wave. When the vehicle travel distance, which is the distance traveled by the vehicle from the time when the drive device of the vehicle was started when the predetermined condition that the ultrasonic wave transmitted by the sensor is received, is equal to or greater than the predetermined distance; The one ultrasonic sensor is covered with a gap and the other ultrasonic sensor side is opened to determine that there is partial blocking snow that is snow adhering to the vehicle. ,
Object detection device. The object detection device according to claim 1,
If the vehicle travel distance is shorter than the predetermined distance when the predetermined condition is met, it is determined that the partial blocking snow does not exist and that an object exists near the one ultrasonic sensor. It is configured,
Object detection device. The object detection device according to claim 1,
If the reverberation time is longer than the predetermined time and the other ultrasonic sensor is not receiving the ultrasonic waves emitted by the one ultrasonic sensor, cover the one ultrasonic sensor without leaving a gap. is configured to determine that there is full-blocking snow that is snow that
Object detection device. The object detection device according to claim 3,
If the predetermined condition is satisfied after it is determined that the full blocking snow exists , it is determined that the partial blocking snow exists even if the vehicle traveling distance at the time the predetermined condition is satisfied is shorter than the predetermined distance. It is configured as follows.
Object detection device. The object detection device according to any one of claims 1 to 4,
Each of the ultrasonic sensors is attached to the vehicle and exposed to the exterior of the vehicle so as to transmit ultrasonic waves toward the exterior of the vehicle.
Object detection device. The object detection device according to claim 5,
The ultrasonic sensors are each attached to the vehicle so as to emit ultrasonic waves in the same direction.
Object detection device.

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