Vehicle controller

A vehicle controller includes: a collision preventing unit that performs a collision avoiding operation of a vehicle with an object around the vehicle, an operation of the collision preventing unit being suppressed when turning behavior of the vehicle is detected; and a control unit that controls the operation of the collision preventing unit so as not to suppress the operation of the collision preventing unit when the vehicle is decelerated. In the vehicle controller 1, the suppression of the operation of the collision preventing unit is alleviated when the vehicle pitches due to deceleration to cause a yaw rate. Accordingly, it is possible to avoid unnecessary suppression of an operation of a collision preventing device due to the pitching of the vehicle when the vehicle is decelerated and to avoid occurrence of a situation in which the suppression of the operation is unnecessarily performed.

TECHNICAL FIELD

The present invention relates to a vehicle controller including a collision preventing device.

BACKGROUND ART

In the related art, a vehicle controller is known which includes a collision preventing device performing a collision avoiding operation. Regarding such a type of vehicle controller, for example, PTL 1 (Japanese Patent Application Publication No. 2010-015450 (JP 2010-015450 A) discloses a technique of controlling a collision preventing device so as to make it difficult to perform a collision avoiding operation when a vehicle takes turning behavior, thereby preventing an object on a curved road side such as a guard rail from being erroneously detected as an obstacle.

CITATION LIST

Patent Literature

SUMMARY OF THE INVENTION

Technical Problem

When a vehicle pitches due to deceleration to thereby cause a yaw rate, this behavior may be detected as turning behavior. Here, by making it difficult to perform a collision avoiding operation at the time of turning behavior as described above, the operation of the collision preventing device may be unnecessarily suppressed, for example, when the vehicle is decelerated at the time of traveling straight. In this way, the vehicle controller in the related art has room for improvement in accuracy of determination of whether to suppress the operation of the collision preventing device.

Therefore, an object of the present invention is to provide a vehicle controller with improved accuracy of determination of whether to suppress an operation of a collision preventing device.

Solution to Problem

In order to achieve the above-mentioned object, according to the present invention, there is provided a vehicle controller including: a collision preventing unit that performs a collision avoiding operation of a vehicle with an object around the vehicle, an operation of the collision preventing unit being suppressed when turning behavior of the vehicle is detected; and a control unit that controls the operation of the collision preventing unit so as not to suppress the operation of the collision preventing unit when the vehicle is decelerated.

In the vehicle controller according to the present invention, the control unit controls the collision preventing unit so as not to suppress the operation of the collision preventing unit when the vehicle is decelerated. Accordingly, even when the vehicle pitches due to deceleration to cause a yaw rate and the yaw rate is detected as turning behavior, it is not difficult to perform a collision avoiding operation. As a result, since a situation in which the operation of the collision preventing unit is unnecessarily suppressed can be avoided, it is possible to improve accuracy of determination of whether to suppress an operation of a collision preventing device.

In the vehicle controller according to the present invention, it is preferable that the control unit control the operation of the collision preventing unit so as not to suppress the operation of the collision preventing unit when the deceleration of the vehicle is greater than or equal to a reference value. According to this invention, when the deceleration of the vehicle is greater than or equal to the reference value, it is not difficult to cause the collision preventing unit to operate and it is thus possible to avoid unnecessary suppression of an operation due to deceleration.

In the vehicle controller according to the present invention, it is preferable that the control unit control the operation of the collision preventing unit so as not to suppress the operation of the collision preventing unit when a brake of the vehicle is operated. According to this invention, when a brake operates, it is not difficult to perform the collision avoiding operation and it is thus possible to avoid unnecessary suppression of the operation with a simple configuration.

The vehicle controller according to the present invention may further include a deceleration unit that automatically decelerates the vehicle, and it is preferable that the control unit control the operation of the collision preventing unit so as not to suppress the operation of the collision preventing unit when the deceleration unit decelerates the vehicle. According to this invention, even when a safety system such as a pre-crash safety system (PCS) that performs a collision avoiding control is mounted on the vehicle, it is not difficult to perform the collision avoiding operation at the time of deceleration and it is thus possible to avoid unnecessary suppression of the operation at the time of deceleration, thereby further improving accuracy of determination of whether to suppress the operation of the collision preventing device.

Advantageous Effects

According to the present invention, it is possible to improve accuracy of determination of whether to suppress an operation of a collision preventing device.

MODES FOR CARRYING OUT THE INVENTION

Hereinafter, an exemplary embodiment of the present invention will be described with reference to the accompanying drawings. In the below description, identical or corresponding elements will be referenced by identical reference signs and description thereof will not be repeated.

As illustrated inFIG. 1, a vehicle controller1according to this embodiment has a PCS function, which is mounted on a vehicle100, of detecting information of the surroundings of the vehicle100and a traveling state of the vehicle100and preventing a collision with an object around the vehicle100. The vehicle controller1includes a collision preventing unit82that performs a collision avoiding operation of the vehicle100with an object around the vehicle100and suppresses an operation of the collision preventing unit82when turning behavior of the vehicle100is detected. The vehicle controller1includes a control unit84that controls the operation of the collision preventing unit82so as not to suppress the operation of the collision preventing unit82when the vehicle100is decelerated. The collision preventing unit82and the control unit84are mounted on, for example, an electronic control unit (ECU)8. The vehicle controller1includes, for example, a millimeter wave sensor2, a vehicle sensor3, and an ECU8.

The millimeter wave sensor2serves as a radar detecting unit that receives reflected waves of RF waves emitted therefrom and that acquires a detection point of an object around the vehicle100. The millimeter wave sensor2is mounted, for example, on the front part and the lateral parts of the vehicle100, scans the front side and the lateral sides of the vehicle100with RF waves of a millimeter wavelength band, and receives RF waves reflected from the surface of an object that is present around the vehicle100. Accordingly, the millimeter wave sensor2recognizes a target as a reflection point of RF waves. The millimeter wave sensor2acquires target information (radar target information) from transmission and reception data of the millimeter waves.

The radar target information includes, for example, a transverse position of a target, a distance between the vehicle100and the target, and a relative velocity between the vehicle100and the target. The millimeter wave sensor2is connected to the ECU8and the radar target information acquired by the millimeter wave sensor2is input to the ECU8.

The vehicle sensor3serves as a traveling state detecting unit that detects a traveling state of the vehicle100. The vehicle sensor3includes, for example, a brake sensor31, a speed sensor32, an acceleration sensor33, and a yaw rate sensor34. The vehicle sensor3is connected to the ECU8and the traveling state of the vehicle100acquired by the vehicle sensor3is input to the ECU8.

The brake sensor31has a function of detecting whether a brake pedal is operated by a driver of the vehicle100. The brake sensor31detects an operating state of the brake pedal by the driver and transmits the detected operating state of the brake pedal as a brake signal to the ECU8.

The speed sensor32has a function of detecting the speed of the vehicle100and is disposed, for example, on the wheels of the vehicle100. The speed sensor32detects, for example, the rotation speed of the vehicle wheels and calculates the vehicle speed of the vehicle100from the detected rotation speed. The speed sensor32transmits the detected vehicle speed of the vehicle100to the ECU8.

The acceleration sensor33has a function of detecting acceleration and deceleration of the vehicle100. The acceleration sensor33is disposed, for example, in the front part of the vehicle100and detects acceleration and deceleration in the front-rear direction of the vehicle100and acceleration and deceleration in the transverse direction. The acceleration sensor33transmits the detected acceleration and deceleration to the ECU8.

The yaw rate sensor34has a function of detecting the yaw rate of the vehicle100. The yaw rate sensor34transmits the detected yaw rate as a yaw rate signal to the ECU8.

The ECU8has a PCS function of determining whether an obstacle is present around the vehicle100on the basis of the information pieces acquired by the millimeter wave sensor2and the vehicle sensor3and performing a collision avoiding operation when it is determined that an obstacle is present. The ECU8is a computer including a central processing unit (CPU) and a memory such as a read only memory (ROM) and a random access memory (RAM) and includes an input signal circuit, an output signal circuit, and a power supply circuit. The ECU8is embodied, for example, by loading an application stored in the ROM into the RAM and causing the CPU to execute the loaded application.

A vehicle controller in the related art will be described below as a comparative example with the vehicle controller1according to this embodiment. In a collision avoiding operation in the related art, for example, when a vehicle is located at a starting point of a curve and is about to travel along the curve as illustrated in part (a) ofFIG. 3or when a vehicle travels along a curve as illustrated in part (b) ofFIG. 3, an object on the roadside such as a guard rail may be erroneously detected as an obstacle. In order to prevent the erroneous detection, the vehicle controller in the related art suppresses the operation of the collision preventing device so as to make it difficult to perform the collision avoiding operation when the vehicle takes turning behavior.

When the vehicle is decelerated, the vehicle may pitch to increase the yaw rate and this behavior may be detected as turning behavior. Accordingly, when the operation of the collision preventing device is suppressed with the turning behavior of the vehicle as described above, the operation is suppressed due to only the pitching based on the deceleration even at the time of straight traveling of the vehicle and it is difficult to perform the collision avoiding operation. In this way, the vehicle controller in the related art has a problem in that the operation of the collision preventing device is unnecessarily suppressed.

Therefore, in the vehicle controller1according to this embodiment, as illustrated inFIG. 1, the ECU8includes an obstacle determining unit81, the collision preventing unit82, a turning behavior detecting unit83, the control unit84, and a deceleration unit85. In order to solve the problem in that the operation of the collision preventing unit is unnecessarily suppressed, the control unit84controls the operation of the collision preventing unit82so as not to suppress the operation of the collision preventing unit82at the time of deceleration of the vehicle. The obstacle determining unit81, the collision preventing unit82, the turning behavior detecting unit83, the control unit84, and the deceleration unit85are not incorporated into the same ECU8as described above, but may be incorporated into different ECUs.

The obstacle determining unit81detects an object around the vehicle100from the information acquired by the millimeter wave sensor2and determines whether an obstacle is present around the vehicle100using the traveling state acquired by the vehicle sensor3. Specifically, the obstacle determining unit81calculates a degree of collision risk of the vehicle100with an object around the vehicle100using the information acquired by the millimeter wave sensor2and the vehicle sensor3, and determines that an obstacle is present, for example, when the degree of collision risk is greater than or equal to a predetermined threshold value. For example, a transverse position of an object around the vehicle100can be used as the information acquired by the millimeter wave sensor2. In this case, it is determined that an obstacle is present when the transverse position detected by the millimeter wave sensor2is less than a predetermined threshold value and it is determined that an obstacle is not present when the transverse position is greater than or equal to the predetermined threshold value.

The collision preventing unit82performs a collision avoiding operation of the vehicle100with an obstacle around the vehicle100. The collision preventing unit82outputs, for example, a warning to a driver of the vehicle100when the obstacle determining unit81determines that an obstacle is present around the vehicle100. Examples of the collision avoiding operation that is performed by the collision preventing unit82include deceleration of the vehicle100by the deceleration unit85and fastening of a seat belt.

The turning behavior detecting unit83has a function of detecting turning behavior of the vehicle100. The turning behavior detecting unit83detects the turning behavior on the basis of the traveling state of the vehicle100acquired by the vehicle sensor3. Specifically, for example, when the vehicle100turns and the yaw rate detected by the yaw rate sensor34is greater than or equal to a predetermined value, the turning behavior detecting unit83detects the turning as the turning behavior.

The control unit84serves to control the operation of the collision preventing unit82and controls the collision preventing unit82so as not to suppress the operation of the collision preventing unit82when the vehicle100is decelerated. Specifically, the control unit84sets a determination threshold value of the obstacle determining unit81and changes the determination threshold value of the obstacle determining unit81so as to make it difficult to cause the collision preventing unit82to operate when the turning behavior is detected and so as to make it easy to cause the collision preventing unit82to operate when the vehicle100is decelerated. For example, when the transverse position is used as the determination threshold value, the control unit84controls the operation of the collision preventing unit82so as to decrease the determination threshold value to make it difficult to determine that an obstacle is present when the turning behavior is detected and so as to increase the determination threshold value to make it easy to determine that an obstacle is present when the vehicle100is decelerated.

The control unit84controls the operation of the collision preventing unit82so as not to suppress the operation of the collision preventing unit82when the brake of the vehicle100is operated. Here, the operation of the brake of the vehicle100may be a driver's operation of the brake detected by the brake sensor31or may be a braking operation that is automatically performed.

The deceleration unit85has a function of automatically decelerating the vehicle100. The deceleration unit85performs a kind of collision avoiding operation of the PCS and decelerates the vehicle100when the obstacle determining unit81determines that an obstacle is present.

The operation of the vehicle controller1according to this embodiment will be described below with reference toFIG. 2. The process illustrated inFIG. 2is performed by the ECU8and is an obstacle determining process of determining whether an obstacle is present around the vehicle100. The obstacle determining process is repeatedly performed every predetermined period of time, for example, while the vehicle100travels.

First, in step S10(hereinafter, referred to as “S10”. The same is true of the other steps.), a process of reading a variety of information is performed. Specifically, the detection results of the millimeter wave sensor2and the vehicle sensor3are transmitted to the ECU8and are stored in the memory of the ECU8. After the process of S10is finished, the process of S12is performed.

In S12, a brake operation determining process of determining whether the brake operates is performed. Specifically, it is determined whether the automatic brake is operated by the deceleration, unit85. Here, the process of S14is performed when it is determined that the automatic brake is not operated, and the process of S16is performed when it is determined that the automatic brake is operated. Instead of determining whether the automatic brake is operated by the deceleration unit85in S12, it may be determined whether the brake is operated by the driver of the vehicle100.

In S14, a deceleration determining process of determining whether the deceleration of the vehicle100is greater than or equal to a reference value is performed. Specifically, the ECU8detects the deceleration of the vehicle100on the basis of the detection result of the acceleration sensor33and it is determined whether the deceleration of the vehicle100is greater than or equal to a threshold value A. Here, the process of S16is performed when it is determined that the deceleration is greater than or equal to the threshold value A, and the process of S18is performed when it is determined that the deceleration is less than the threshold value A. The value of the threshold value A is not particularly limited, but may be set to, for example, 0.3 [G]. The value of the threshold value A may be appropriately calculated, for example, on the basis of the relationship of the deceleration and the pitching angle of the vehicle100and the vertical angle of millimeter waves.

In S16, a threshold value setting process is performed by the control unit84. Specifically, the threshold value is set by the control unit84so as to make it easy for the collision preventing unit82to perform the collision avoiding operation. For example, when the obstacle determining process is performed on the basis of the transverse position, the control unit84sets the threshold value to a greater value and, for example, the threshold value of ±0.5 [m] is changed to ±1.0 [m]. This change of the threshold value makes it easy to determine that an obstacle is present and makes it easy for the collision preventing unit82to perform the collision avoiding operation. After the process of S16is finished, the process of S18is performed.

In S18, an obstacle determining process is performed by the obstacle determining unit81. Specifically, the obstacle determining unit81determines whether an obstacle is present by comparing the detection results of the millimeter wave sensor2and the vehicle sensor3with the threshold value. For example, when it is determined whether an obstacle is present on the basis of the transverse position, the obstacle determining unit81determines that an obstacle is present when the transverse position of an object around the vehicle100is less than or equal to the threshold value, and determines that an obstacle is not present when the transverse position is greater than the threshold value. When it is determined that an obstacle is present, the collision avoiding operation is performed by the collision preventing unit82. For example, the deceleration of the vehicle100by the deceleration unit85, the warning to the driver of the vehicle100, or fastening of a seat belt, is performed. After the process of S18is finished, the flow of the processes ends.

As described above, in this embodiment, the vehicle controller1includes the collision preventing unit82that performs the collision avoiding operation of the vehicle100with an object around the vehicle100, in which the operation of the collision preventing unit82is suppressed when the turning behavior of the vehicle100is detected, and the control unit84that controls the operation of the collision preventing unit82so as not to suppress the operation of the collision preventing unit82when the vehicle100is decelerated.

As described above, the vehicle controller1according to this embodiment controls the operation of the collision preventing unit so as not to make it difficult to perform the collision avoiding operation when the vehicle100is decelerated. Accordingly, when the vehicle pitches due to the deceleration and this behavior is detected as turning behavior, the suppression of the operation of the collision preventing unit82is alleviated. As a result, since a situation in which the operation of the collision preventing unit82is unnecessarily suppressed can be avoided at the time of deceleration of the vehicle100or the like, it is possible to improve accuracy of determination of whether to suppress the operation of the collision preventing unit82.

In the vehicle controller1according to this embodiment, the control unit84includes the control unit84that controls the operation of the collision preventing unit82so as not to suppress the operation of the collision preventing unit82when the deceleration of the vehicle100is greater than or equal to the threshold value A. Accordingly, when the deceleration of the vehicle100is greater than or equal to the threshold value A, the suppression of the operation of the collision preventing unit82is alleviated and it is thus possible to avoid unnecessary suppression of the operation.

In the vehicle controller1according to this embodiment, the control unit84controls the operation of the collision preventing unit82so as not to suppress the operation of the collision preventing unit82when the brake of the vehicle100is operated. Accordingly, when the brake is operated, the suppression of the operation of the collision preventing unit82is alleviated and it is thus possible to avoid unnecessary suppression of the operation with a simple configuration.

The vehicle controller1according to this embodiment includes the deceleration unit85that automatically decelerates the vehicle100, and the control unit84controls the operation of the collision preventing unit82so as not to suppress the operation of the collision preventing unit82when the deceleration unit85decelerates the vehicle100. Accordingly, even when a safety system such as a PCS of performing a collision avoiding control is mounted on the vehicle, it is not difficult to perform the collision avoiding operation at the time of deceleration and it is thus possible to avoid unnecessary suppression of the operation.

The above-mentioned embodiment is an example of the vehicle controller according to the present invention, and the vehicle controller according to the present invention is not limited to the embodiment. The vehicle controller according to the present invention can be modified without changing the gist of the appended claims, or may be applied to other devices.

For example, the above-mentioned embodiment describes that two determinations of the determination of whether the PCS brake operates and the determination of whether the deceleration of the vehicle100is greater than or equal to the threshold value A are performed as illustrated in S12and S14ofFIG. 2, but only one of the determinations may be performed.

The above-mentioned embodiment describes the example where the control unit84changes the determination threshold value of the obstacle determining unit81so as to make it easy for the collision preventing unit82to perform the collision avoiding operation when the brake is operated or the deceleration of the vehicle100is greater than or equal to the threshold value A. However, the technique of making it easy to perform the collision avoiding operation is not limited to this example. For example, the determination threshold value may be calculated on the basis of at least one of the deceleration of the vehicle100and the brake operation state of the vehicle100and the threshold value may be dynamically set in each case. Accordingly, it is possible to control the operation of the collision preventing unit82with higher accuracy. The control unit84may alleviate the suppression of the operation of the collision preventing unit82at the time of deceleration without using the threshold value.

The above-mentioned embodiment describes the example where the millimeter wave sensor2is used, but a sensor using RF waves of a different wavelength band such as a sensor using microwaves or sub millimeter waves may be used instead of the millimeter wave sensor2. Any sensor may be used instead of the millimeter wave sensor2, as long as it can measure the positional relationship between the vehicle100and an object around the vehicle100.

REFERENCE SIGNS LIST

1: vehicle controller

2: millimeter wave sensor

3: vehicle sensor

32: speed sensor

34: yaw rate sensor

81: obstacle determining unit

82: collision preventing unit

83: turning behavior detecting unit

84: control unit

A: threshold value