JP2014089073A - Driving support apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving support apparatus configured to prevent driving support from being hindered due to snow stuck on a sensor.SOLUTION: A driving support apparatus includes: a sensor which transmits a detection wave to the outside of a vehicle, and acquires object information on a distance to an object outside the vehicle on the basis of a reflection wave of the detection wave; and a processing apparatus which determines the object as an obstacle to be detected upon determination that the object has been continuously detected for a predetermined reference time or more on the basis of the object information from the sensor, and starts driving support with respect to the obstacle. When the distance to the object based on the object information from the sensor is equal to or less than a predetermined distance and snow accumulation environment is detected, the processing apparatus changes a criterion for determining the predetermined reference time continuity so that the object is less likely to be determined as an obstacle to be detected.

Description

  The present invention relates to a driving support device.

  Conventionally, in a vehicle equipped with a distance sensor that measures the distance between an obstacle in the traveling direction of the host vehicle and the host vehicle, when the distance from the obstacle is equal to or less than a predetermined distance when the host vehicle is stopped, the vehicle 2. Description of the Related Art There is known a vehicle collision damage reduction control device characterized in that it has means for restricting the vehicle to a starting speed at which the vehicle cannot start or is below a predetermined acceleration (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2004-280489

  However, since the distance sensor is generally provided outside the vehicle, there are cases where snow adheres during traveling due to hoisting or the like. When snow adheres to the distance sensor, the distance sensor detects the distance from the snow that is not the original detection target, which may hinder driving support.

  Therefore, an object of the present invention is to provide a driving assistance device that can reduce troubles in driving assistance caused by snow sticking to a sensor.

In order to achieve the above object, according to one aspect of the present invention, a sensor that transmits a detection wave to the outside of the vehicle and acquires object information related to a distance to the object outside the vehicle based on the reflected wave of the detection wave;
Based on the object information from the sensor, when it is determined that an object is detected with a time continuity equal to or greater than a predetermined reference, the object is determined as an obstacle to be detected, and driving assistance related to the obstacle is provided. A processing device to start,
When the distance to the object based on the object information from the sensor is equal to or less than a predetermined distance and a snowy environment is detected, the processing device determines the time continuity determination criterion equal to or greater than the predetermined reference as the object. A driving support device is provided, wherein the driving support device is changed in a direction in which it is difficult to determine an obstacle to be detected.

  ADVANTAGE OF THE INVENTION According to this invention, the driving assistance apparatus which can reduce the trouble of the driving assistance resulting from the adhesion of snow to a sensor is obtained.

It is a block diagram which shows an example of the system configuration | structure containing the driving assistance device 1 by one Example. It is a figure which shows an example of the obstacle determination process performed by driving assistance ECU10. It is a figure which shows an example of an obstacle determination aspect in case 1st determination threshold value Th1 is used. It is a figure which shows an example of the obstruction determination aspect in case 2nd determination threshold value Th2 is used.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram illustrating an example of a system configuration including a driving support device 1 according to an embodiment.

  In FIG. 1, the driving support device 1 includes a driving support ECU 10. The driving support ECU 10 is configured by a microcomputer and includes, for example, a ROM that stores a control program, a readable / writable RAM that stores calculation results, a timer, a counter, an input interface, an output interface, and the like.

  Note that the function of the driving support ECU 10 may be realized by arbitrary hardware, software, firmware, or a combination thereof. For example, any part or all of the functions of the driving assistance ECU 10 may be realized by an application-specific integrated circuit (ASIC) or a field programmable gate array (FPGA) for a specific application. Further, part or all of the functions of the driving assistance ECU 10 may be realized by another ECU (for example, a clearance sonar ECU 20). Further, the driving assistance ECU 10 may realize part or all of the functions of another ECU (for example, the clearance sonar ECU 20).

  The driving support ECU 10 includes a clearance sonar ECU (hereinafter referred to as a clearance sonar ECU) 20, clearance sonars 201a, 201b, 201c, 201d, a G sensor 30, a steering angle sensor 40, an outside air temperature sensor 42, a meter computer 50, an engine ECU 60, and a brake. An ECU 70 or the like may be connected. For example, the driving assistance ECU 10 can communicate with the clearance sonar ECU 20, the G sensor 30, the rudder angle sensor 40, the outside air temperature sensor 42, the meter computer 50, the engine ECU 60, and the brake ECU 70 through a CAN (Controller Area Network), a direct line, or the like. May be connected.

  The clearance sonars 201a, 201b, 201c, and 201d are ultrasonic sensors and are provided at appropriate locations on the vehicle body. The clearance sonars 201a, 201b, 201c, and 201d are examples of sensors that detect the presence or absence of a relatively close object having a detection distance of, for example, several centimeters to several meters, or the distance to the object. In the illustrated example, two clearance sonars 201a and 201b are provided on the front bumper, and two clearance sonars 201c and 201d are provided on the rear bumper. However, the number and arrangement of the sensors are not limited to the illustrated example, and for example, four sensors may be provided on the front, four on the rear, and two on the side. The clearance sonars 201a to 201d output detection results (object information) in the respective detection ranges to the clearance sonar ECU 20, respectively.

  The clearance sonars 201a, 201b, 201c, and 201d may operate while the vehicle speed is in a low speed region that is greater than zero. Further, the clearance sonars 201a and 201b for detecting the front object operate when traveling in the forward drive range (for example, the D range), and the clearance sonars 201c and 201d for detecting the rear object are operated when traveling in the reverse range (during reverse). ).

  The clearance sonar ECU 20 processes the detection results input from the clearance sonars 201a to 201d and calculates a “target distance” that is a distance to the object. The clearance sonar ECU 20 transmits the calculated target distance information (distance information) to the driving support ECU 10. For example, the clearance sonar ECU 20 may measure the distance to the object by measuring the time until the ultrasonic wave irradiated from the clearance sonar is reflected by the object and the reflected wave returns. If the detection angle of the clearance sonar is as wide as 90 °, for example, the direction of the object is not specified only by the detection result from the single clearance sonar. However, the clearance sonar ECU 20 may specify the position (direction) of the object by obtaining the distance from the plurality of clearance sonars to the object, or the shape of the object (for example, the shape of a wall or a utility pole) May be determined.

  The G sensor 30 measures the acceleration in the front-rear direction of the vehicle, and transmits the measurement result to the driving support ECU 10 as “vehicle front-rear G” information. The acceleration in the front-rear direction of the vehicle measured by the G sensor 30 is the total value of the acceleration calculated from the wheel speed and the acceleration of gravity due to the road inclination (vehicle inclination). Therefore, the inclination of the road can be measured by subtracting the acceleration calculated from the wheel speed from the vehicle longitudinal G measured by the G sensor 30.

  The steering angle sensor 40 detects the steering angle of the steering wheel and transmits it to the driving support ECU 10 as steering angle information.

  The outside air temperature sensor 42 detects the environmental temperature outside the vehicle. The outside air temperature sensor 42 may be shared with a sensor used for controlling the air conditioner.

  The meter computer 50 is connected to a combination meter device (not shown) for notifying the driver by display, an alarm sound generator (not shown) for notifying the driver by voice, and the like. . The meter computer 50 controls numerical values, characters, figures, indicator lamps, and the like displayed on the combination meter device in response to a request from the driving support ECU 10, and also generates alarm sounds and alarm sounds to be notified by the notification sound generator. Take control.

  The engine ECU 60 controls the operation of an engine that is a driving source of the vehicle, and controls, for example, ignition timing, fuel injection amount, and the like. The engine ECU 60 controls the engine output based on a requested driving force from a driving support ECU 10 described later. In the case of a hybrid vehicle, the engine ECU 60 may control (suppress) the driving force in accordance with the required driving force from the driving support ECU 10 in cooperation with the hybrid ECU that controls the hybrid system. In the case of a hybrid vehicle or an electric vehicle, the motor output may be controlled based on the required driving force from the driving support ECU 10.

  Further, the engine ECU 60 may transmit information on the accelerator pedal operation, information on the accelerator pedal opening rate, and shift position information to the driving support ECU 10. The information on the accelerator pedal operation is information representing the amount of operation of an accelerator pedal (not shown), and the information on the accelerator pedal opening rate is information representing the accelerator opening. The shift position information is information representing the position of the shift lever, and is P (parking), R (reverse), N (neutral), D (drive), or the like. The information on the accelerator pedal operation may be acquired directly from the accelerator position sensor. Further, the shift position information may be acquired from an ECU that controls the transmission, or may be directly acquired from a shift position sensor.

  The brake ECU 70 controls the braking device of the vehicle. For example, the brake ECU 70 controls a brake actuator that operates a hydraulic brake device disposed on each wheel (not shown). The brake ECU 70 controls the output (wheel cylinder pressure) of the brake actuator based on the required braking force from the driving support ECU 10 described later. The brake actuator may include a pump that generates high-pressure oil (and a motor that drives the pump), various valves, and the like. The hydraulic circuit configuration of the braking device is arbitrary. The hydraulic circuit of the braking device may be configured so that the wheel cylinder pressure can be increased regardless of the depression amount of the brake pedal by the driver. Typically, a high pressure hydraulic source other than the master cylinder (a pump that generates high pressure oil, An accumulator). Further, a circuit configuration typically used in a brake-by-wire system represented by ECB (Electric Control Braking system) may be adopted. In the case of a hybrid vehicle or an electric vehicle, the motor output (regenerative operation) may be controlled based on the required braking force from the driving support ECU 10.

  Further, the brake ECU 70 may transmit brake pedal operation information and wheel speed information to the driving support ECU 10. The wheel speed information may be based on, for example, a signal from a wheel speed sensor provided on each wheel (not shown). The vehicle speed (vehicle speed) and acceleration / deceleration can be calculated from the wheel speed information. The brake pedal operation information may be obtained directly from the brake pedal force switch or the master cylinder pressure sensor. Similarly, the wheel speed information (or vehicle speed information) is directly from the wheel speed sensor or the drive shaft rotation sensor. May be acquired.

  The driving assistance ECU 10 includes an ICS application (Intelligent Clarence Sonar application) 100. In the illustrated example, the ICS application 100 is software that operates on the driving support ECU 10, and includes an input processing unit 101, a vehicle state estimation unit 102, an obstacle determination unit 103, a control amount calculation unit 104, and an HMI (Human Machine Interface) calculation. Unit 105 and an output processing unit 106.

  Based on the information from the clearance sonar ECU 20, the driving support ECU 10 performs driving support so that the vehicle does not collide with an object determined as an obstacle. Driving support includes an alarm (cooperation with the meter computer 50) that prompts the driver to perform an independent brake operation, suppression of driving force through intervention (cooperation with the engine ECU 60), and generation of braking force through intervention (braking) Cooperation with the ECU 70).

  The input processing unit 101 performs input processing of various information received by the driving support ECU 10. For example, information received according to the CAN communication standard is converted into information that can be used by the ICS application 100. The input processing unit 101 receives distance information from the clearance sonar ECU 20, information on the vehicle longitudinal G from the G sensor 30, steering angle information from the steering angle sensor 40, and outside air temperature information from the outside air temperature sensor 42. The input processing unit 101 also receives information on the accelerator pedal operation, information on the accelerator pedal opening rate, and shift position information from the engine ECU 60, and further receives information on the brake pedal operation and wheel speed from the brake ECU 70. Is entered.

  The vehicle state estimation unit 102 has a function of estimating the vehicle state based on the various information input to the input processing unit 101. For example, the vehicle state estimation unit 102 may determine whether or not a vehicle state in which the clearance sonars 201a to 201d should operate is formed.

  The obstacle determination unit 103 determines whether an object detected by the clearance sonars 201a to 201d is an obstacle to be detected based on the target distance received from the clearance sonar ECU 20 (obstacle determination). The obstacle determination is executed using a predetermined determination threshold Th. That is, each piece of object information detected by the clearance sonars 201a to 201d may be generated due to the presence of noise or an object that cannot become an obstacle (for example, snow fixed to the clearance sonars 201a to 201d). . Therefore, whether or not the object information detected by the clearance sonars 201a to 201d is object information related to the obstacle to be detected is determined based on the determination threshold Th. Note that specific examples of the obstacle determination method and the determination threshold Th determination method will be described in detail later. Obstacle determination may be performed independently on the object information relating to each of the clearance sonars 201a to 201d.

  The obstacle determination unit 103 performs a collision determination on an object determined (determined) as an obstacle to be detected based on object information and the like related to the object detected by the clearance sonars 201a to 201d. Specifically, the obstacle determination unit 103 determines whether or not the detected object is highly likely to collide with the own vehicle (whether or not the object should avoid collision by driving assistance). For example, the obstacle determination unit 103 is based on the object information related to the object detected by the clearance sonars 201a to 201d, the steering angle information received from the steering angle sensor 40, the wheel speed information received from the brake ECU 70, and the like. For example, the distance to the object is less than a predetermined distance, the vehicle speed is greater than or equal to a predetermined value (or the required deceleration is greater than or equal to a predetermined threshold), and the object is located in a range that cannot be avoided by a steering operation. When doing so, you may determine with the own vehicle colliding with an object.

  The control amount calculation unit 104 calculates a control amount for driving support. For example, the control amount calculation unit 104 calculates a required driving force for suppressing the driving force when an object determined (determined) as an obstacle to be detected is located within a predetermined distance. Further, when the obstacle determination unit 103 determines that the vehicle collides with the object, it calculates a deceleration (target deceleration) necessary to avoid the collision with the object, and responds to the target deceleration. The required braking force is calculated.

  The HMI calculation unit 105 is a calculation unit for outputting various types of information for alerting the driver to an obstacle when an obstacle to be detected is detected. The HMI calculation unit 105 performs calculation for notifying the driver by a display device, a sound device, a vibration device, or the like (not shown) through the meter computer 50, for example.

  The output processing unit 106 outputs the control amount (required driving force and required braking force) calculated by the control amount calculating unit 104 and the calculation result (output information) calculated by the HMI calculating unit 105 to the engine ECU 60, the brake ECU 70, and the meter. In order to transmit to the computer 50, for example, the signal is converted into a signal according to the CAN communication standard and output.

  FIG. 2 is a diagram illustrating an example of the obstacle determination process executed by the driving support ECU 10. The processing routine shown in FIG. 2 may be executed at predetermined intervals during the operation of the clearance sonars 201a to 201d. For example, the clearance sonars 201a to 201d may be ones that perform only the clearance sonar on the traveling direction side and perform sound wave transmission / reception processing at predetermined intervals while the vehicle speed is in a low speed region greater than zero. The processing routine shown in FIG. 2 may be executed independently for distance information related to each of the clearance sonars 201a to 201d. Below, the process performed with respect to the distance information which concerns on the clearance sonar 201c is demonstrated as an example.

  In step 200, based on distance information from the clearance sonar ECU 20 (distance information related to the clearance sonar 201c), it is determined whether distance information that is a target distance equal to or less than the predetermined distance D0 is obtained. The distance information that is the target distance equal to or smaller than the predetermined distance D0 may be distance information related to the object that is input for the first time this time. That is, in the previous cycle, no object has been detected (that is, distance information has not been obtained), distance information is newly obtained in this cycle, and the target distance indicated by the distance information is predetermined. It may be a case where the distance is equal to or less than D0. However, the distance information that is the target distance equal to or smaller than the predetermined distance D0 may be distance information related to an object that has been input before the previous cycle. That is, the same object has been detected before the previous cycle (that is, the distance information has been obtained), and the target distance indicated by the distance information obtained in the current cycle becomes the predetermined distance D0 or less for the first time in the current cycle. May be the case. The predetermined distance D0 may correspond to the maximum value of the range of the target distance obtained when snow adheres to the clearance sonar 201c and depends on the clearance sonar 201c, but may be, for example, a distance of 50 cm or less. In this step 200, when distance information that is a target distance equal to or smaller than the predetermined distance D0 is obtained, the process proceeds to step 202. In other cases, the processing of the current cycle is terminated, and an object equal to or smaller than the predetermined distance D0. It will be in the waiting state waiting for the distance information which is a target distance to be obtained.

  In step 202, it is determined whether or not the external environment of the vehicle is a snowy environment. The presence or absence of this snow accumulation may be determined (estimated) by any method. For example, whether or not the external environment of the vehicle is a snowy environment may be determined based on date / time information (information indicating the season such as winter) or weather information obtained from the outside (for example, a center server) by wireless communication. Good. Whether the external environment of the vehicle is a snowy environment may be determined based on a captured image of the in-vehicle camera, or may be determined from an on / off state of the snow mode. Further, whether or not the external environment of the vehicle is a snowy environment may be determined based on the outside air temperature information from the outside air temperature sensor 42. For example, when the outside air temperature is a low temperature lower than a predetermined temperature, it may be determined that the external environment of the vehicle is a snowy environment. In this case, the predetermined temperature may correspond to the maximum temperature in the temperature range when snow falls. If the external environment of the vehicle is a snowy environment, the process proceeds to step 204. Otherwise, the process proceeds to step 208.

  In step 204, it is determined whether or not there has been a predetermined shift change immediately before based on the shift position information. The predetermined shift change is a shift gear shift change from the reverse range to the forward drive range (eg, D range), or a shift gear shift change from the forward drive range (eg, D range) to the reverse range. Good. This is because when the shift is changed, the snow is stuck to the clearance sonars 201a and 201b or the clearance sonars 201c and 201d which are the front side in the traveling direction at the present time due to the winding of the snow during traveling in the reverse direction until just before. This is because there is a high possibility of being. For example, when the shift gear shift is changed from the forward drive range (for example, D range) to the reverse range, there is a possibility that snow is stuck to the clearance sonars 201c and 201d due to the rolling of snow by the rear wheels when traveling in the forward direction. This is because it is expensive.

  The term “immediately before” is because the amount of snow attached by winding is the largest immediately after a predetermined shift change, and then decreases due to falling or the like. The “immediately before” may be a few seconds before the current time. When the predetermined shift is changed, the operation states of the clearance sonars 201a to 201d are changed. For example, when there is a shift shift of the shift gear from the forward drive range (eg, D range) to the reverse range, the front object detection clearance sonars 201a and 201b are stopped, and the rear object detection clearance sonar 201c and 201d is started. In this case, “immediately before” may be only the first processing cycle (processing cycle in FIG. 2) started from the start of operation of the clearance sonars 201c and 201d for detecting the rear object, or 2, 3 Up to the th processing cycle. For example, when it is only the first processing cycle that starts from the start of the operation of the clearance sonars 201c and 201d for detecting the rear object, for detecting the rear object accompanying the shift gear shift change from the forward drive range to the reverse range. Step 204 is affirmed in the first processing cycle immediately after the operation of the clearance sonars 201c and 201d. If there is a predetermined shift change immediately before, the process proceeds to step 206; otherwise, the process proceeds to step 208.

  In step 206, the determination threshold Th used for the obstacle determination is set to the second determination threshold Th2, and the obstacle determination is executed at the second determination threshold Th2.

  In step 208, the determination threshold Th used for the obstacle determination is set to the normal first determination threshold Th1 (<Th2), and the obstacle determination is executed with the first determination threshold Th1. The first determination threshold Th1 is significantly smaller than the second determination threshold Th2, and may be, for example, half of the second determination threshold Th2.

  Here, an example of the obstacle determination method using the determination threshold Th will be described in relation to Step 206 and Step 208. Obstacle determination refers to determination as to whether or not the object (object information) detected by the clearance sonar 201c is an obstacle to be detected (object information related to the obstacle) as described above.

  Specifically, first, an index value indicating the time continuity of detection of the object in question is calculated. That is, an index value indicating how long the object in question is continuously detected by the clearance sonar 201c is calculated. The index value may be, for example, an integrated value of the time when the object is detected by the clearance sonar 201c. For example, if an object starts to be detected from a certain period T0 and then continues to be detected for five consecutive periods up to the current period T4, the index value may be 5T (T is equal to one period) time). In this case, when the object is temporarily not detected in a certain cycle, the index value may be reset to 0, or the time corresponding to the cycle in which the object is not detected may be subtracted. Further, the index value may be the number of periods in which the object is detected by the clearance sonar 201c. For example, if the object starts to be detected from a certain period T0 and then continues to be detected for five periods until the current period T4, the index value may be 5. Also in this case, when the object is temporarily not detected in a certain period, the index value may be reset to 0, or the number of periods that are no longer detected may be subtracted. When the state in which no object is detected continues for a predetermined period or longer, it may be considered that the object has not been detected (in this case, the index value is 0, and even if the same object starts to be detected thereafter). , Treated as a new object).

  The index value calculated in this way is compared with the determination threshold Th, and when the index value is equal to or higher than the determination threshold Th, it is determined (determined) that the object related to the index value is an obstacle to be detected. ) On the other hand, if the index value does not exceed the determination threshold Th, the object related to the index value is not determined (determined) as an obstacle to be detected until the index value exceeds the determination threshold Th (unconfirmed). State).

  When it is determined that the object detected by the clearance sonar 201c is an obstacle to be detected, driving assistance related to the object (typically driving assistance that prevents the vehicle from colliding with the object) ) Is started. Note that “start of driving support” here does not necessarily mean that driving force suppression or the like immediately starts to be executed, but may include that the obstacle to be detected starts to be monitored as a monitoring target. Good. For example, when the distance from the own vehicle to the object is within a predetermined distance D1, the driving force is suppressed and an alarm is output, and the distance from the own vehicle to the object is the predetermined distance D2 (<D1). If it falls within the range, automatic generation of braking force (intervention braking) may be executed. The predetermined distances D1 and D2 may be larger than the predetermined distance D0 in step 200. However, the predetermined distance D2 may be equal to or smaller than the predetermined distance D0 in step 200.

  FIG. 3 is a diagram illustrating an example of an obstacle determination mode when the first determination threshold Th1 (see step 208 in FIG. 2) is used. FIG. 3A illustrates an object detected by the clearance sonar 201c. FIG. 3B shows the time series change of the index value indicating the time continuity of object detection. Here, the index value is an integrated value of the time detected by the clearance sonar 201c.

  In the example shown in FIG. 3, the object starts to be detected at time t0 and is continuously detected until time t2. In this case, as shown in FIG. 3B, the index value gradually increases and becomes equal to or greater than the first determination threshold Th1 at time t1. Therefore, from time t0 to time t1, the object detected by the clearance sonar 201c is not determined as an obstacle to be detected (unconfirmed state), and is determined as an obstacle to be detected at time t2. become. If it is determined that the object detected by the clearance sonar 201c is an obstacle to be detected, driving assistance related to the object is started. In other words, in the example shown in the figure, driving assistance regarding an object (obstacle to be detected) detected by the clearance sonar 201c is started from time t2. Note that, as described above, “starting driving assistance” does not necessarily mean that driving force suppression or the like immediately starts to be executed, but includes that an obstacle to be detected starts to be monitored as a monitoring target. But you can.

  FIG. 4 is a diagram illustrating an example of an obstacle determination mode when the second determination threshold Th2 (see step 206 in FIG. 2) is used. FIG. 4A illustrates an object detected by the clearance sonar 201c. FIG. 4B shows the time series change of the index value indicating the time continuity of the object detection. Here, the index value is an integrated value of the time during which the object is detected by the clearance sonar 201c.

  In the example shown in FIG. 4, as in the example shown in FIG. 3, the object starts to be detected at time t0 and is detected continuously until time t2, but is not detected after time t2. In this case, as shown in FIG. 4B, the index value gradually increases until time t2, but does not become greater than or equal to the second determination threshold Th2 by time t2. In other words, the object that has started to be detected by the clearance sonar 201c at time t0 becomes undetectable (lost) before the first determination threshold value Th1 is reached. In this case, the object detected by the clearance sonar 201c ends without being determined as an obstacle to be detected (in an undetermined state). Therefore, driving assistance is not started for this object.

  As described above, according to the present embodiment, when a predetermined shift change is performed during snow accumulation and the target distance based on the object information from the clearance sonar 201c is equal to or less than the predetermined distance D0 (snow is stuck to the clearance sonar 201c). The object detected by the clearance sonar 201c is detected by changing the determination threshold Th to the second determination threshold Th2 that is larger than the first determination threshold Th1 in the normal state. It is possible to lengthen (delay) the time until the obstacle is confirmed. As a result, when there is a possibility that snow is stuck to the clearance sonar 201c, a more "careful" obstacle determination is realized, and the reliability of driving support can be improved.

  More specifically, when there is snow, there is a possibility that the snow will stick to the clearance sonars 201a to 201d due to the winding of snow during vehicle travel. For example, during traveling in a forward drive range (for example, D range), there is a high possibility that snow is stuck to the clearance sonars 201c and 201d due to the winding of snow by the rear wheels. At this time, when the driver changes the shift gear shift from the forward drive range to the reverse range and starts reverse travel, the operations of the clearance sonars 201c and 201d are started. However, at this time, if snow adheres to the clearance sonars 201c and 201d, object information is generated from the clearance sonars 201c and 201d due to the snow. As a result, a very short target distance (distance to snow) can be calculated, but when such a target distance is calculated, an alarm or other operation is immediately performed even though no obstacle actually exists. There is a risk that assistance will be implemented. For example, when the normal first determination threshold value Th1 is used, driving assistance such as an alarm may be executed at time t1, as shown in FIG. 3B.

  On the other hand, when the second determination threshold value Th2 is used, as shown in FIG. 4B, driving assistance such as an alarm is not executed at time t1, and the attached snow is not detected. Until t2, the obstacle to be detected is not determined. Thereby, it is possible to prevent the driving assistance from being executed in an inappropriate situation due to the adhesion of snow. In the example shown in FIG. 4B, the attached snow is not detected at time t2, but the snow is still attached, and the index value may be equal to or higher than the second determination threshold Th2 after time t2. It is possible. In this case, a very short target distance (distance to snow) is calculated at that time, and driving assistance such as an alarm can be immediately executed even though no obstacle actually exists. However, also in this case, since the timing of the alarm or the like is delayed as compared with the case where the normal first determination threshold Th1 is used, the uncomfortable feeling given to the driver can be reduced.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, in the above-described embodiment, the second determination threshold Th2 that is larger than the normal first determination threshold Th1 when distance information of a target distance equal to or less than the predetermined distance D0 is detected after a predetermined shift change at the time of snowfall. However, when distance information of a target distance equal to or less than the predetermined distance D0 is detected during snowfall, a second determination threshold Th2 that is larger than the normal first determination threshold Th1 may be used. That is, the predetermined shift change condition (step 204) may be omitted. This is because, for example, snow may adhere to the clearance sonars 201a and 201b on the front side during forward traveling. Further, the predetermined shift change condition may include other shift changes. For example, the predetermined shift change condition may include a change from the neutral range to the reverse range or the D range. This is because snow may adhere to the clearance sonar on the opposite side in the traveling direction due to winding during inertial running in the neutral range. The predetermined shift change condition may include a change from the P range to the reverse range or the D range. This is because the snow may adhere to the clearance sonar by direct snow blowing or the like while the vehicle is stopped.

  In the above-described embodiment, the second determination threshold Th2 that is larger than the normal first determination threshold Th1 is detected when distance information of a target distance equal to or less than the predetermined distance D0 is detected after a predetermined shift change at the time of snowfall. However, other conditions may be added so that the second determination threshold Th2 is used only when snow is attached in a more accurate manner. For example, when the target distance changes significantly with time (for example, when the target distance changes according to a change in travel distance), it may be determined that the detected object is not snow stuck to the clearance sonar 201a. (In other words, it may be determined as an obstacle to be detected).

  Further, in the above-described embodiment, when the distance information of the target distance equal to or less than the predetermined distance D0 is detected after the predetermined shift change at the time of snowfall, by changing the determination threshold Th, Although the timing to be confirmed is delayed, it is also possible to obtain the same effect by changing the index value calculation method. For example, when distance information of a target distance equal to or less than a predetermined distance D0 is detected after a predetermined shift change at the time of snowfall, the same is achieved by correcting the calculated index value (for example, correcting to a value of 50%). It is also possible to obtain an effect.

  In the embodiment described above, the integrated value compared with the second determination threshold Th2 (that is, the integrated value used in the obstacle determination in step 206) is detected by the specific clearance sonar within the predetermined distance D0. It may be the accumulated time or the like. On the other hand, the integrated value compared with the first determination threshold Th1 (that is, the integrated value calculated in the obstacle determination in step 208) is an integrated time during which the object is detected at an arbitrary distance by a specific clearance sonar. It may be. The obstacle determination may also be executed when an object is detected outside a predetermined distance D0 by a certain clearance sonar. In this case, the first determination threshold Th1 may be used, and the integrated value compared with the first determination threshold Th1 may be an integrated time during which an object is detected at an arbitrary distance by the clearance sonar.

  Further, in the above-described embodiment, the snow adhesion determination for periodically determining whether or not snow has adhered to the clearance sonars 201a and 201b (at the time of forward movement) or the clearance sonars 201c and 201d (at the time of backward movement) of the traveling direction front side. It may be done. In this case, the snow adhesion determination is performed, for example, when the distance information of the target distance equal to or less than the predetermined distance D3 is detected and the vehicle travels over the predetermined distance D3 (or when the vehicle travels over the predetermined vehicle speed for a predetermined time). It may be determined that snow is attached. The processing routine shown in FIG. 2 may be executed during snow adhesion determination (until a determination result is obtained) while omitting the determination in step 204.

  Moreover, although the ultrasonic sensor is used in the above-described embodiments, the present invention can also be applied to the case of using another sensor (for example, a millimeter wave sensor or a laser sensor) that can detect an obstacle.

1 Driving assistance device 10 Driving assistance ECU
20 Crisona ECU
30 G sensor 40 Rudder angle sensor 42 Outside air temperature sensor 50 Meter computer 60 Engine ECU
70 Brake ECU
DESCRIPTION OF SYMBOLS 101 Input processing part 102 Vehicle state estimation part 103 Obstacle determination part 104 Control amount calculating part 105 HMI calculating part 106 Output processing part 201a-201d Clearance sonar

Claims (3)

A sensor that transmits a detection wave to the outside of the vehicle and acquires object information related to a distance to the object outside the vehicle based on a reflected wave of the detection wave;
Based on the object information from the sensor, when it is determined that an object is detected with a time continuity equal to or greater than a predetermined reference, the object is determined as an obstacle to be detected, and driving assistance related to the obstacle is provided. A processing device to start,
When the distance to the object based on the object information from the sensor is equal to or less than a predetermined distance and a snowy environment is detected, the processing device determines the time continuity determination criterion equal to or greater than the predetermined reference as the object. A driving support device, characterized in that it is changed in a direction that makes it difficult to determine an obstacle to be detected.   In the processing device, the distance from the sensor to the object based on the object information is a predetermined distance or less, the external temperature is lower than the predetermined temperature, and the shift gear shifts from the reverse range to the driving range in the forward direction. The driving support device according to claim 1, wherein the determination criterion is changed when there is a change or a shift gear shift change from a drive range in the forward direction to a reverse range. Based on the object information from the sensor, the processing device calculates an index value representing an integrated time in which the object is continuously detected or the number of times the object has been detected, and the calculated index value Is determined to be an obstacle to be detected when the threshold exceeds a predetermined threshold,
The driving support device according to claim 1, wherein the change of the determination criterion includes increasing the predetermined threshold value.

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