Patent Description:
There is known a vehicle collision avoidance assist apparatus that is configured to execute a collision avoidance control including (i) a forcibly steering control and (ii) a forcibly braking control for avoiding a collision of an own vehicle with an object ahead of the own vehicle (for example, see <CIT>). The forcibly steering control is a control of forcibly steering the own vehicle to avoid a collision of the own vehicle with the object even when a driver of the own vehicle does not operate a steering wheel of the own vehicle. The forcibly braking control is a control of forcibly applying a braking force to the own vehicle to avoid a collision of the own vehicle with the object even when the driver of the own vehicle does not operate a brake pedal of the own vehicle.

The vehicle collision avoidance assist apparatus starts executing the collision avoidance control when the own vehicle approaches the object ahead of the own vehicle or a forward object, and a predetermined timing has come. In order to surely avoid the collision of the own vehicle with the forward object by the collision avoidance control, it is preferred to start executing the collision avoidance control at an early time. However, if the start timing of starting executing the collision avoidance control is too early, an execution of the collision avoidance control may be started when the driver of the own vehicle thinks that the own vehicle is not so close to the forward vehicle to an extent that the driver needs to start driving operations, such as the operations of pressing the brake pedal and rotating the steering wheel for avoiding a collision of the own vehicle with the forward object. In this case, the driver may feel discomfort. However, if the start timing of starting executing the collision avoidance control is too late, the collision of the own vehicle with the forward object may not be avoided even when the collision avoidance control is executed. Other vehicle collision avoidance assist apparatuses were disclosed in <CIT> and <CIT>.

An object of the invention is to provide a vehicle collision avoidance assist apparatus which can start executing the collision avoidance control at a timing capable of surely avoiding the collision of the own vehicle with the forward vehicle without providing the driver of the own vehicle with a discomfort.

According to the invention, a vehicle collision avoidance assist apparatus is configured according to claim <NUM>.

With the invention, when the driver does not have a probability that the driver can carry out a driving operation for avoiding a collision of the own vehicle with the object, an execution of the collision avoidance control is started at a relatively early timing. On the other hand, when the driver has the probability that the driver can carry out the driving operation for avoiding a collision of the own vehicle with the object, the execution of the collision avoidance control is started at a relatively late timing. Thus, the execution of the collision avoidance control can be started at a timing capable of surely avoiding the collision of the own vehicle with the object without providing the driver with discomfort.

According to an aspect of the invention, the electronic control unit may be configured to execute a forcibly steering control for forcibly steering the own vehicle as the collision avoidance control to avoid a collision of the own vehicle with the object ahead of the own vehicle.

With this aspect of the invention, the execution of the forcibly steering control can be started at a timing capable of surely avoiding the collision of the own vehicle with the object without providing the driver with discomfort.

According to another aspect of the invention, the electronic control unit may be configured to detect a grasping state of the driver of the own vehicle grasping a steering wheel of the own vehicle. In this aspect, the electronic control unit may be configured to determine whether the driver of the own vehicle has the collision self-avoidance probability, based on the grasping state.

The grasping state of the driver grasping the steering wheel effectively represents the collision self-avoidance probability. With this aspect of the invention, whether the driver has the collision self-avoidance probability is determined, based on the grasping state of the driver grasping the steering wheel. Thus, whether the driver has the collision self-avoidance probability can be appropriately determined.

According to further another aspect of the invention, the electronic control unit may be configured to detect a grasping action of grasping the steering wheel carried out by the driver of the own vehicle as the grasping state.

The grasping action of grasping the steering wheel by the driver effectively represents the collision self-avoidance probability. With this aspect of the invention, whether the driver has the collision self-avoidance probability is determined, based on the grasping action of grasping the steering wheel by the driver. Thus, whether the driver has the collision self-avoidance probability can be appropriately determined.

According to further another aspect of the invention, the electronic control unit may be configured to detect portions of the steering wheel which the driver of the own vehicle grasps as the grasping state.

The portions of the steering wheel which the driver grasps effectively represent the collision self-avoidance probability. With this aspect of the invention, whether the driver has the collision self-avoidance probability is determined, based on the portions of the steering wheel which the driver grasps. Thus, whether the driver has the collision self-avoidance probability can be appropriately determined.

According to further another aspect of the invention, the electronic control unit may be configured to detect a consciousness state of the driver of the own vehicle and determine the collision self-avoidance probability, based on the consciousness state.

The driver's consciousness state effectively represents the collision self-avoidance probability. With this aspect of the invention, whether the driver has the collision self-avoidance probability is determined, based on the driver's consciousness state. Thus, whether the driver has the collision self-avoidance probability can be appropriately determined.

According to further another aspect of the invention, the electronic control unit may be configured to detect a grasping state of the driver of the own vehicle grasping a steering wheel of the own vehicle and a consciousness state of the driver of the own vehicle. In this aspect, the electronic control unit may be configured to determine whether the driver of the own vehicle has the collision self-avoidance probability, based on the grasping state and the consciousness state. Further, in this case, when the electronic control unit determines that the driver of the own vehicle does not have the collision self-avoidance probability, based on the consciousness state, the electronic control unit may be configured to set the start timing to start executing the collision avoidance control to a timing earlier than the start timing set when the electronic control unit determines that the driver of the own vehicle does not have the collision self-avoidance probability, based on the grasping state.

When the driver's consciousness state shows that the driver does not have the collision self-avoidance probability, the collision self-avoidance probability is low, compared with when the driver's steering wheel grasping state shows that the driver does not have the collision self-avoidance probability. With this aspect of the invention, when the electronic control unit determines that the driver does not have the collision self-avoidance probability, based on the driver's consciousness state, the execution of the collision avoidance control is started at a time earlier than when the electronic control unit determines that the driver does not have the collision self-avoidance probability, based on the driver's steering wheel grasping state. Thus, the execution of the collision avoidance control can be started at an appropriate timing.

According to further another aspect of the invention, the electronic control unit may be configured to detect a grasping state of the driver of the own vehicle grasping a steering wheel of the own vehicle and a consciousness state of the driver of the own vehicle. In this aspect, the electronic control unit may be configured to determine whether the driver of the own vehicle has the collision self-avoidance probability, based on the grasping state and the consciousness state. Further in this aspect, when the electronic control unit determines that the driver of the own vehicle does not have the collision self-avoidance probability, based on the consciousness state, and the driver of the own vehicle has the collision self-avoidance probability, based on the grasping state, the electronic control unit may be configured to determine that the driver of the own vehicle does not have the collision self-avoidance probability.

When the driver's steering wheel grasping state shows that the driver has the collision self-avoidance probability, but the driver's consciousness state shows that the driver does not have the collision self-avoidance probability, the collision self-avoidance probability is probably low. With this aspect of the invention, when even if the electronic control unit determines that the driver has the collision self-avoidance probability, based on the driver's steering wheel grasping state, but the electronic control unit determines that the driver does not have the collision self-avoidance probability, based on the driver's consciousness state, the electronic control unit conclusively determines that the driver does not have the collision self-avoidance probability. Thus, the execution of the collision avoidance control can be started at an appropriate timing.

According to further another aspect of the invention, the electronic control unit may be configured to determine that the driver of the own vehicle does not have the collision self-avoidance probability when the electronic control unit determines that the driver of the own vehicle has the collision self-avoidance probability, based on the consciousness state, and the driver of the own vehicle does not have the collision self-avoidance probability, based on the grasping state.

When the driver's consciousness state shows that the driver has the collision self-avoidance probability, but the driver's steering wheel grasping state shows that the driver does not have the collision self-avoidance probability, the collision self-avoidance probability is probably relatively low. With this aspect of the invention, when the electronic control unit determines that the driver has the collision self-avoidance probability, based on the driver's consciousness state, but the electronic control unit determines that the driver does not have the collision self-avoidance probability, based on the driver's steering wheel grasping state, the electronic control unit conclusively determines that the driver does not have the collision self-avoidance probability. Thus, the execution of the collision avoidance control can be started at an appropriate timing.

Elements of the invention are not limited to elements of embodiments and modified examples of the invention described with reference to the drawings. The other objects, features and accompanied advantages of the invention can be easily understood from the embodiments and the modified examples of the invention.

Below, a vehicle collision avoidance assist apparatus according to an embodiment of the invention will be described with reference to the drawings. As shown in <FIG>, the vehicle collision avoidance assist apparatus <NUM> according to the embodiment of the invention is installed on an own vehicle <NUM>.

The vehicle collision avoidance assist apparatus <NUM> includes an ECU <NUM>. ECU stands for electronic control unit. The ECU <NUM> includes a microcomputer as a main component. The microcomputer includes a CPU, a ROM, a RAM, a non-volatile memory, and an interface. The CPU is configured or programmed to realize various functions by executing instructions, programs, or routines memorized in the ROM.

Further, a driving apparatus <NUM>, a braking apparatus <NUM>, and a steering apparatus <NUM> are installed on the own vehicle <NUM>.

The driving apparatus <NUM> is an apparatus that outputs a driving torque TQ_D or a driving force to be applied to the own vehicle <NUM> to move the own vehicle <NUM>. The driving apparatus <NUM> includes, for example, an internal combustion engine and at least one electric motor. The driving apparatus <NUM> is electrically connected to the ECU <NUM>. The ECU <NUM> can control the driving torque TQ_D output from the driving apparatus <NUM> by controlling activations of the driving apparatus <NUM>.

The braking apparatus <NUM> is an apparatus that outputs a braking torque TQ_B or a braking force to be applied to the own vehicle <NUM> to brake the own vehicle <NUM>. The braking apparatus <NUM> includes, for example, a brake apparatus. The braking apparatus <NUM> is electrically connected to the ECU <NUM>. The ECU <NUM> can control the braking torque TQ_B output from the braking apparatus <NUM> by controlling activations of the braking apparatus <NUM>.

The steering apparatus <NUM> is an apparatus that outputs a steering torque TQs or a steering force to be applied to the own vehicle <NUM> to steer the own vehicle <NUM>. The steering apparatus <NUM> includes, for example, a power steering apparatus. The steering apparatus <NUM> is electrically connected to the ECU <NUM>. The ECU <NUM> can control the steering torque TQs output from the steering apparatus <NUM> by controlling activations of the steering apparatus <NUM>.

Further, an accelerator pedal <NUM>, an accelerator pedal operation amount sensor <NUM>, a brake pedal <NUM>, a brake pedal operation amount sensor <NUM>, a steering wheel <NUM>, a steering shaft <NUM>, a steering angle sensor <NUM>, a steering torque sensor <NUM>, a grasping state detection apparatus <NUM>, a vehicle kinetic momentum detection apparatus <NUM>, a surrounding information detection apparatus <NUM>, and a consciousness state detection apparatus <NUM> are installed on the own vehicle <NUM>.

The accelerator pedal operation amount sensor <NUM> is a sensor that detects an operation amount of the accelerator pedal <NUM>. The accelerator pedal operation amount sensor <NUM> is electrically connected to the ECU <NUM>. The accelerator pedal operation amount sensor <NUM> sends information on the detected operation amount of the accelerator pedal <NUM> to the ECU <NUM>. The ECU <NUM> acquires the operation amount of the accelerator pedal <NUM> as an accelerator pedal operation amount AP, based on the information sent from the accelerator pedal operation amount sensor <NUM>.

In addition, the ECU <NUM> calculates and acquires a requested driving torque TQ_D_req or a requested driving force, based on the accelerator pedal operation amount AP and a vehicle moving speed V100 of the own vehicle <NUM>. The requested driving torque TQ_D_req is a driving torque TQ_D requested to be output from the driving apparatus <NUM>. The ECU <NUM> controls the activations of the driving apparatus <NUM> so as to output the driving torque corresponding to the requested driving torque TQ_D_req.

The brake pedal operation amount sensor <NUM> is a sensor that detects an operation amount of the brake pedal <NUM>. The brake pedal operation amount sensor <NUM> is electrically connected to the ECU <NUM>. The brake pedal operation amount sensor <NUM> sends information on the detected operation amount of the brake pedal <NUM> to the ECU <NUM>. The ECU <NUM> acquires the operation amount of the brake pedal <NUM> as a brake pedal operation amount BP, based on the information sent from the brake pedal operation amount sensor <NUM>.

In addition, the ECU <NUM> calculates and acquires a requested braking torque TQ_B_req or a requested braking force, based on the brake pedal operation amount BP. The requested braking torque TQ_B_req is a braking torque TQ_B requested to be output from the braking apparatus <NUM>. The ECU <NUM> controls the activations of the braking apparatus <NUM> so as to output the braking torque corresponding to the requested braking torque TQ_B_req.

The steering angle sensor <NUM> is a sensor that detects a rotation angle of the steering shaft <NUM> with respect to a neutral position. The steering angle sensor <NUM> is electrically connected to the ECU <NUM>. The steering angle sensor <NUM> sends information on the detected rotation angle of the steering shaft <NUM> to the ECU <NUM>. The ECU <NUM> acquires the rotation angle of the steering shaft <NUM> as a steering angle θsteer, based on the information sent from the steering angle sensor <NUM>.

The steering torque sensor <NUM> is a sensor that detects a torque input to the steering shaft <NUM> via the steering wheel <NUM> by a driver of the own vehicle <NUM>. The steering torque sensor <NUM> is electrically connected to the ECU <NUM>. The steering torque sensor <NUM> sends information on the detected torque to the ECU <NUM>. The ECU <NUM> acquires the torque input to the steering shaft <NUM> via the steering wheel <NUM> by the driver as a driver input toque TQs_driver, based on the information sent from the steering torque sensor <NUM>.

The grasping state detection apparatus <NUM> is an apparatus that detects a grasping state of the driver of the own vehicle <NUM> grasping the steering wheel <NUM>. In this embodiment, the grasping state detection apparatus <NUM> includes a touch sensor <NUM> mounted on the steering wheel <NUM>.

The touch sensor <NUM> is a sensor that detects a touch interaction to the steering wheel <NUM> carried out by the driver of the own vehicle <NUM>. The touch sensor <NUM> is electrically connected to the ECU <NUM>. When the touch sensor <NUM> detects the touch interaction to the steering wheel <NUM> carried by the driver of the own vehicle <NUM>, the touch sensor <NUM> sends information or a signal on a portion of the steering wheel <NUM> which the driver of the own vehicle <NUM> touches to the ECU <NUM>. The ECU <NUM> can recognize the portion of the steering wheel <NUM> which the driver of the own vehicle <NUM> touches, based on the information or the signal sent from the touch sensor <NUM>.

The vehicle kinetic momentum detection apparatus <NUM> is an apparatus that detects kinetic momenta of the own vehicle <NUM>. In this embodiment, the vehicle kinetic momentum detection apparatus <NUM> includes a vehicle moving speed detection device <NUM>, a longitudinal acceleration sensor <NUM>, a lateral acceleration sensor <NUM>, and a yaw rate sensor <NUM>.

The vehicle moving speed detection device <NUM> is a device that detects a vehicle moving speed of the own vehicle <NUM>. The vehicle moving speed detection device <NUM> includes, for example, vehicle wheel rotation speed sensors. The vehicle moving speed detection device <NUM> is electrically connected to the ECU <NUM>. The vehicle moving speed detection device <NUM> sends information on the detected vehicle moving speed of the own vehicle <NUM> to the ECU <NUM>. The ECU <NUM> acquires a vehicle moving speed V100 of the own vehicle <NUM>, based on the information sent from the vehicle moving speed detection device <NUM>.

In addition, the ECU <NUM> calculates and acquires a requested steering torque TQs_req, based on the acquired steering angle θsteer, the acquired driver input torque TQs_driver, and the acquired vehicle moving speed V100. The requested steering torque TQs_req is a steering torque TQs requested to be output from the steering apparatus <NUM>. The ECU <NUM> controls the activations of the steering apparatus <NUM> so as to output the steering torque corresponding to the requested steering torque TQs_req from the steering apparatus <NUM>. It should be noted that when the ECU <NUM> executes a forcibly steering control described later, the ECU <NUM> suitably determines the steering torque TQs necessary to move the own vehicle <NUM> along a target avoidance route Rtgt as the requested steering torque TQs_req and controls the activations of the steering apparatus <NUM> so as to output the steering torque corresponding to the requested steering torque TQs_req.

The longitudinal acceleration sensor <NUM> is a sensor that detects a longitudinal acceleration of the own vehicle <NUM>. The longitudinal acceleration sensor <NUM> is electrically connected to the ECU <NUM>. The longitudinal acceleration sensor <NUM> sends information on the detected acceleration to the ECU <NUM>. The ECU <NUM> acquires the longitudinal acceleration of the own vehicle <NUM> as a longitudinal acceleration value Gx, based on the information sent from the longitudinal acceleration sensor <NUM>.

The lateral acceleration sensor <NUM> is a sensor that detects a lateral (width direction) acceleration of the own vehicle <NUM>. The lateral acceleration sensor <NUM> is electrically connected to the ECU <NUM>. The lateral acceleration sensor <NUM> sends information on the detected acceleration to the ECU <NUM>. The ECU <NUM> acquires the lateral acceleration of the own vehicle <NUM> as a lateral acceleration value Gy, based on the information sent from the lateral acceleration sensor <NUM>.

The yaw rate sensor <NUM> is a sensor that detects a yaw rate YR of the own vehicle <NUM>. The yaw rate sensor <NUM> is electrically connected to the ECU <NUM>. The yaw rate sensor <NUM> sends information on the detected yaw rate YR to the ECU <NUM>. The ECU <NUM> acquires the yaw rate YR of the own vehicle <NUM>, based on the information sent from the yaw rate sensor <NUM>.

The surrounding information detection apparatus <NUM> is an apparatus that detects information on a surrounding of the own vehicle <NUM>. In this embodiment, the surrounding information detection apparatus <NUM> includes radio wave sensors <NUM> and image sensors <NUM>. The radio wave sensor <NUM> is, for example, a radar sensor or a millimeter wave radar. The image sensor <NUM> is, for example, a camera. It should be noted that the surrounding information detection apparatus <NUM> may include sonic sensors such as ultrasonic wave sensors or clearance sonars and/or optical sensors such as laser radars or LiDAR.

The radio wave sensors <NUM> are electrically connected to the ECU <NUM>. The radio wave sensor <NUM> transmits radio waves and receives the radio waves reflected on an object, i.e., reflected waves. The radio wave sensor <NUM> sends information or detection results on the transmitted radio waves and the received radio waves, i.e., the received reflected waves to the ECU <NUM>. In other words, the radio wave sensor <NUM> detects an object around the own vehicle <NUM> and sends the information or the detection result on the detected object to the ECU <NUM>. The ECU <NUM> can acquire information on the object around the own vehicle <NUM> as surrounding detection information I_D, based on the information or radio wave information sent from the radio wave sensors <NUM>.

It should be noted that the object is a vehicle, a motor bike, a bicycle, or a person.

The image sensors <NUM> are also electrically connected to the ECU <NUM>. The image sensor <NUM> takes images of a view around the own vehicle <NUM> and sends information on the taken images to the ECU <NUM>. The ECU <NUM> can acquire information on the surrounding of the own vehicle <NUM> as the surrounding detection information I_D, based on the information, i.e., image information sent from the image sensors <NUM>.

As shown in <FIG>, when there is an object or a forward object <NUM> ahead of the own vehicle <NUM>, the ECU <NUM> detects the forward object <NUM>, based on the surrounding detection information I_D. It should be noted that the forward object <NUM> is, for example, a vehicle, a motor bike, a bicycle, or a person. In an example shown in <FIG>, the forward object <NUM> is a vehicle.

When the ECU <NUM> detects the forward object <NUM>, the ECU <NUM> acquires an object distance D200 and a relative speed ΔV200, for example, based on the surrounding detection information I_D. The object distance D200 is a distance between the forward object <NUM> and the own vehicle <NUM>. The relative speed ΔV200 is a speed of the own vehicle <NUM> with respect to the forward object <NUM>.

In addition, the ECU <NUM> recognizes a left lane marking LM_L and a right lane marking LM_R, based on the surrounding detection information I_D. The left lane marking LM_L and the right lane marking LM_R define a moving lane of the own vehicle <NUM> or an own vehicle moving lane LN. The ECU <NUM> can determine an area of the own vehicle moving lane LN, based on the recognized left and right lane markings LM, i.e., the recognized left lane marking LM_L and the recognized right lane marking LM_R.

The consciousness state detection apparatus <NUM> is an apparatus that detects a consciousness state of the driver of the own vehicle <NUM>. In this embodiment, the consciousness state detection apparatus <NUM> is a driver monitor camera <NUM>. The driver monitor camera <NUM> is provided in an interior of the own vehicle <NUM>, facing the driver of the own vehicle <NUM> so as to take an image of a face of the driver of the own vehicle <NUM>.

The driver monitor camera <NUM> is a camera that takes images of a face of the driver of the own vehicle <NUM>. The driver monitor camera <NUM> is electrically connected to the ECU <NUM>. The driver monitor camera <NUM> sends information or image data on the taken images of the face of the driver to the ECU <NUM>. The ECU <NUM> determines whether eyes of the driver of the own vehicle <NUM> are open, i.e., the driver of the own vehicle <NUM> is conscious, based on the information sent from the driver monitor camera <NUM>.

It should be noted that the ECU <NUM> may be configured to acquire vital data such as a temperature, a pulse, and a blood pressure of the driver of the own vehicle <NUM> and determine whether the driver of the own vehicle <NUM> is awake, i.e., whether the driver of the own vehicle <NUM> is conscious, based on the acquired vital data.

Next, a summary of operations of the vehicle collision avoidance assist apparatus <NUM> will be described.

The vehicle collision avoidance assist apparatus <NUM> executes a process of detecting objects such as vehicles in a moving direction of the own vehicle <NUM>, i.e., ahead of the own vehicle <NUM>, based on the surrounding detection information I_D while the own vehicle <NUM> moves. The own vehicle <NUM> executes a normal moving control while the vehicle collision avoidance assist apparatus <NUM> detects no objects in the moving direction of the own vehicle <NUM>, i.e., ahead of the own vehicle <NUM>.

The normal moving control is a control of (i) controlling the activations of the driving apparatus <NUM> to output the driving torque corresponding to the requested driving torque TQ_D_req from the driving apparatus <NUM> when the requested driving torque TQ_D_req or the requested driving force is greater than zero, (ii) controlling the activations of the braking apparatus <NUM> to output the braking torque corresponding to the requested braking torque TQ_B_req from the braking apparatus <NUM> when the requested braking torque TQ_B_req or the requested braking force is greater than zero, and (iii) controlling the activations of the steering apparatus <NUM> to output the steering torque corresponding to the requested steering torque TQs_req from the steering apparatus <NUM> when the requested steering torque TQs_req or the requested steering force is greater than zero.

When the vehicle collision avoidance assist apparatus <NUM> detects an object or the forward object <NUM> ahead of the own vehicle <NUM> in the moving direction of the own vehicle <NUM>, the vehicle collision avoidance assist apparatus <NUM> determines whether the object is in a predicted moving area A100, based on the surrounding detection information I_D.

As shown in <FIG>, the predicted moving area A100 is an area which has (i) a center line corresponding to a predicted moving route R100 of the own vehicle <NUM> and (ii) a width equal to a width of the own vehicle <NUM>. The predicted moving route R100 is a moving route along which the own vehicle <NUM> predictively moves if the own vehicle <NUM> moves, maintaining the current steering angle θsteer. The predicted moving route R100 shown in <FIG> is a straight line, but may be a curved line.

When the detected forward object <NUM> is not in the predicted moving area A100, the vehicle collision avoidance assist apparatus <NUM> continues executing the normal moving control.

On the other hand, when the vehicle collision avoidance assist apparatus <NUM> determines that the detected forward object <NUM> is in the predicted moving area A100, the vehicle collision avoidance assist apparatus <NUM> determines a collision probability. The collision probability is a probability that the own vehicle <NUM> collides with the forward object <NUM>.

In this embodiment, the vehicle collision avoidance assist apparatus <NUM> acquires an object distance D200 and determines the collision probability, based on whether the acquired object distance D200 is equal to or shorter than a predetermined distance or a collision probability determination distance Dth. The object distance D200 is a distance between the forward object <NUM> and the own vehicle <NUM>.

When (i) the own vehicle <NUM> approaches the forward object <NUM> as shown in <FIG>, (ii) the object distance D200 decreases to the collision probability determination distance Dth, and (iii) the vehicle collision avoidance assist apparatus <NUM> determines that the object distance D200 is equal to or shorter than the collision probability determination distance Dth, the vehicle collision avoidance assist apparatus <NUM> determines that an avoidance route acquisition condition Croute becomes satisfied.

When the vehicle collision avoidance assist apparatus <NUM> determines that the avoidance route acquisition condition Croute becomes satisfied, the vehicle collision avoidance assist apparatus <NUM> starts a process of acquiring an avoidance route R, based on the surrounding detection information I_D.

The avoidance route R is a route along which the own vehicle <NUM> is moved for avoiding a collision of the own vehicle <NUM> with the forward object <NUM>. When the own vehicle <NUM> is moved along the avoidance route R, the own vehicle <NUM> moves within the own vehicle moving lane LN and passes by the forward object <NUM> as shown in <FIG>.

It should be noted that the avoidance route R of an example shown in <FIG> passes a right side of the forward object <NUM>, but when there is a space at a left side of the forward object <NUM> which allows the vehicle collision avoidance assist apparatus <NUM> to cause the own vehicle <NUM> to move and pass by the forward object <NUM> within the own vehicle moving lane LN, a route passing the left side of the forward object <NUM> may be acquired as the avoidance route R.

In addition, when (i) the object distance D200 becomes equal to or shorter than the collision probability determination distance Dth, and (ii) the vehicle collision avoidance assist apparatus <NUM> determines that the own vehicle <NUM> has the collision probability, the vehicle collision avoidance assist apparatus <NUM> determines that a forcibly steering start determination condition Cd_steer becomes satisfied.

When the vehicle collision avoidance assist apparatus <NUM> determines that the forcibly steering start determination condition Cd_steer becomes satisfied, the vehicle collision avoidance assist apparatus <NUM> determines a start timing to start executing a forcibly steering control or a forcibly steering start timing Ts_steer.

According to the invention, the vehicle collision avoidance assist apparatus <NUM> determines the forcibly steering start timing Ts_steer, based on a predicted reaching time TTC. The predicted reaching time TTC is a time predictively taken for the own vehicle <NUM> to reach the forward object <NUM>. The vehicle collision avoidance assist apparatus <NUM> acquires the predicted reaching time TTC by dividing the object distance D200 by the relative speed ΔV200 (TTC = D200/ ΔV200).

As far as the forward object <NUM> is in the predicted moving area A100, the vehicle collision avoidance assist apparatus <NUM> executes processes of acquiring the object distance D200, the relative speed ΔV200, and the predicted reaching time TTC with a predetermined calculation cycle.

The vehicle collision avoidance assist apparatus <NUM> determines whether the predicted reaching time TTC decreases to a predetermined time or a collision determination time TTCth. It should be noted that the predicted reaching time TTC decreases as the own vehicle <NUM> approaches the forward object <NUM> assuming that the relative speed ΔV200 is constant.

As long as the predicted reaching time TTC is greater than the collision determination time TTCth, the vehicle collision avoidance assist apparatus <NUM> continues to execute the normal moving control.

On the other hand, when (i) the own vehicle <NUM> approaches the forward object <NUM>, and (ii) the predicted reaching time TTC decreases to the collision determination time TTCth as show in <FIG> without a collision avoidance steering wheel operation carried out by the driver of the own vehicle <NUM>, i.e., an operation to the steering wheel <NUM> carried out by the driver of the own vehicle <NUM> to avoid the collision of the own vehicle <NUM> with the forward object <NUM>, the vehicle collision avoidance assist apparatus <NUM> determines that the own vehicle <NUM> collides with the forward object <NUM> if the own vehicle <NUM> continues moving, keeping the current driving state of the own vehicle <NUM>. When the vehicle collision avoidance assist apparatus <NUM> determines so, the vehicle collision avoidance assist apparatus <NUM> determines that a condition for executing the forcibly steering control, i.e., a forcibly steering execution condition Cs_steer becomes satisfied, and the forcibly steering start timing Ts_steer has come.

When the vehicle collision avoidance assist apparatus <NUM> determines that the forcibly steering start timing Ts_steer has come, the vehicle collision avoidance assist apparatus <NUM> sets, as the target avoidance route Rtgt, the avoidance route R which the vehicle collision avoidance assist apparatus <NUM> acquires or has acquired at this time and starts executing the forcibly steering control of controlling the steering force applied to the own vehicle <NUM> so as to cause the own vehicle <NUM> to move along the target avoidance route Rtgt.

While the vehicle collision avoidance assist apparatus <NUM> executes the forcibly steering control, the vehicle collision avoidance assist apparatus <NUM> acquires a current position of the own vehicle <NUM>, based on the longitudinal acceleration value Gx, the lateral acceleration value Gy, the yaw rate YR, and the left and right lane markings LM, and controls the steering force applied to the own vehicle <NUM>, based on the acquired current position of the own vehicle <NUM> so as to cause the own vehicle <NUM> to move along the target avoidance route Rtgt.

Thereby, the own vehicle <NUM> starts turning as shown in <FIG>. Immediately afterward, the own vehicle <NUM> turns in the opposite direction, and the moving direction of the own vehicle <NUM> becomes parallel to the own vehicle moving lane LN. Then, the own vehicle <NUM> moves at the side of the forward object <NUM> as shown in <FIG>. Thereby, the collision of the own vehicle <NUM> with the forward object <NUM> is avoided. After the own vehicle <NUM> passes by the forward object <NUM> as shown in <FIG>, the vehicle collision avoidance assist apparatus <NUM> terminates executing the forcibly steering control.

It should be noted that when the vehicle collision avoidance assist apparatus <NUM> cannot acquire the avoidance route R due to the reason that there is no space at the side of the forward object <NUM> to allow the own vehicle <NUM> to move at a point of time when the forcibly steering start timing Ts_steer has come, the vehicle collision avoidance assist apparatus <NUM> does not execute the forcibly steering control.

Further, the vehicle collision avoidance assist apparatus <NUM> may be configured to decelerate the own vehicle <NUM> by decreasing the driving force applied to the own vehicle <NUM> or limiting the driving force applied to the own vehicle <NUM> to a certain value or less in addition to executing the forcibly steering control.

Furthermore, the vehicle collision avoidance assist apparatus <NUM> may be configured to apply the braking force to the own vehicle <NUM> to decelerate and stop the own vehicle <NUM> in addition to executing the forcibly steering control. In this case, the vehicle collision avoidance assist apparatus <NUM> may be configured to terminate executing the forcibly steering control when the own vehicle <NUM> stops.

Furthermore, the vehicle collision avoidance assist apparatus <NUM> may be configured to stop executing the forcibly steering control when the driver input torque TQs_driver becomes equal to or greater than a relatively great predetermined torque TQth while the vehicle collision avoidance assist apparatus <NUM> executes the forcibly steering control, in other words, when the driver of the own vehicle <NUM> applies an operation having an operation amount equal to or greater than a predetermined amount to the steering wheel <NUM> while the vehicle collision avoidance assist apparatus <NUM> executes the forcibly steering control.

In order to surely avoid a collision of the own vehicle <NUM> with the forward object <NUM> by the forcibly steering control, the start timing to start executing the forcibly steering control is preferably early. However, if the start timing to start executing the forcibly steering control is too early, an execution of the forcibly steering control may be started when the driver of the own vehicle <NUM> thinks that the own vehicle <NUM> is not so close to the forward object <NUM> to an extent that the driver needs to start the collision avoidance steering wheel operation (i.e., a rotation operation of rotating the steering wheel <NUM> for avoiding the collision of the own vehicle <NUM> with the forward object <NUM>). In this case, the driver may feel a discomfort. However, if the start timing to start executing the forcibly steering control is too late, the collision of the own vehicle <NUM> with the forward object <NUM> cannot be avoided even when the forcibly steering control is executed.

When the eyes of the driver of the own vehicle <NUM> are closed due to drowsiness or blackouts, the driver of the own vehicle <NUM> cannot recognize that the own vehicle <NUM> is going to collide with the forward object <NUM>. In this case, the driver may probably not carry out the collision avoidance steering wheel operation or a collision avoidance steering operation. In this case, even when the execution of the forcibly steering control is started at an early timing, the driver does not feel discomfort.

Further, when the driver of the own vehicle <NUM> cannot carry out the sufficient steering wheel operation for avoiding a collision of the own vehicle <NUM> with the forward object <NUM> since the driver does not grasp the steering wheel <NUM> or grasps the steering wheel <NUM> with only one hand, the execution of the forcibly steering control is preferably started at an early timing.

Accordingly, the vehicle collision avoidance assist apparatus <NUM> sets the forcibly steering start timing Ts_steer, depending on a situation of the driver of the own vehicle <NUM> as described below. In this embodiment, the vehicle collision avoidance assist apparatus <NUM> sets the forcibly steering start timing Ts_steer, depending on the situation of the driver by setting the collision determination time TTCth, depending on the situation of the driver.

The vehicle collision avoidance assist apparatus <NUM> determines whether the driver of the own vehicle <NUM> has a collision self-avoidance probability. The collision self-avoidance probability is a probability that the driver of the own vehicle <NUM> carries out the steering wheel operation as a driving operation to avoid the collision of the own vehicle <NUM> with the forward object <NUM>.

When the vehicle collision avoidance assist apparatus <NUM> determines that the driver of the own vehicle <NUM> does not have the collision self-avoidance probability, the vehicle collision avoidance assist apparatus <NUM> sets the forcibly steering start timing Ts_steer earlier than the forcibly steering start timing Ts_steer set when the vehicle collision avoidance assist apparatus <NUM> determines that the driver of the own vehicle <NUM> has the collision self-avoidance probability. The forcibly steering start timing Ts_steer is advanced by increasing the collision determination time TTCth. Thus, according to the invention, when the vehicle collision avoidance assist apparatus <NUM> determines that the driver of the own vehicle <NUM> does not have the collision self-avoidance probability, the vehicle collision avoidance assist apparatus <NUM> sets the collision determination time TTCth to a time greater than the collision determination time TTCth set when the vehicle collision avoidance assist apparatus <NUM> determines that the driver of the own vehicle <NUM> has the collision self-avoidance probability.

Whether the driver of the own vehicle <NUM> has the collision self-avoidance probability is determined, based on a driver's consciousness state and a driver's steering wheel grasping state.

In this embodiment, the driver's consciousness state corresponds to whether the eyes of the driver of the own vehicle <NUM> are open, i.e., whether the driver of the own vehicle <NUM> is conscious. The vehicle collision avoidance assist apparatus <NUM> determines the driver's consciousness state, based on the information provided from the driver monitor camera <NUM>.

In this embodiment, the vehicle collision avoidance assist apparatus <NUM> executes a process of determining whether the driver of the own vehicle <NUM> has the collision self-avoidance probability, based on the driver's consciousness state with a predetermined cycle, independently of whether the forcibly steering start determination condition Cd_steer is satisfied. However, the vehicle collision avoidance assist apparatus <NUM> may be configured to execute the process of determining whether the driver of the own vehicle <NUM> has the collision self-avoidance probability, based on the driver's consciousness state when the forcibly steering start determination condition Cd_steer becomes satisfied.

When the vehicle collision avoidance assist apparatus <NUM> determines that the driver is conscious, the vehicle collision avoidance assist apparatus <NUM> determines that the driver of the own vehicle <NUM> has the collision self-avoidance probability. On the other hand, when the vehicle collision avoidance assist apparatus <NUM> determines that the driver is unconscious, the vehicle collision avoidance assist apparatus <NUM> determines that the driver of the own vehicle <NUM> does not have the collision self-avoidance probability.

Further, the driver's steering wheel grasping state is determined, based on whether (i) the driver of the own vehicle <NUM> grasps the steering wheel <NUM> with both hands, and (ii) portions of the steering wheel <NUM> which the driver grasps, are specified portions 35P. The vehicle collision avoidance assist apparatus <NUM> determines the driver's steering wheel grasping state, in particular, the portions of the steering wheel <NUM> which the driver of the own vehicle <NUM> grasps, based on the information provided from the touch sensor <NUM>.

In this embodiment, the specified portions 35P are two portions, i.e., a portion 35PR of the steering wheel <NUM> and a portion 35PL of the steering wheel <NUM>, respectively as shown in <FIG>. The portion 35PR is a portion of the steering wheel <NUM> which has (i) an area of a predetermined angle θp and (ii) a center position clockwise from an uppermost center portion 35C of the steering wheel <NUM> by <NUM> degrees. The portion 35PL is a portion of the steering wheel <NUM> which has (i) an area of the predetermined angle θp and (ii) a center position counterclockwise from the uppermost center portion 35C of the steering wheel <NUM> by <NUM> degrees. The uppermost center portion 35C is an uppermost portion of the steering wheel <NUM> when the steering wheel <NUM> is positioned at a neutral position.

In this embodiment, the vehicle collision avoidance assist apparatus <NUM> executes a process of determining whether the driver of the own vehicle <NUM> has the collision self-avoidance probability, based on the driver's steering wheel grasping state with a predetermined cycle, independently of whether the forcibly steering start determination condition Cd_steer is satisfied. However, the vehicle collision avoidance assist apparatus <NUM> may be configured to execute the process of determining whether the driver of the own vehicle <NUM> has the collision self-avoidance probability, based on the driver's steering wheel grasping state when the forcibly steering start determination condition Cd_steer becomes satisfied.

When the driver of the own vehicle <NUM> grasps the specified portions 35P of the steering wheel <NUM> with both hands, the vehicle collision avoidance assist apparatus <NUM> determines that the driver of the own vehicle <NUM> has the collision self-avoidance probability. On the other hand, when the driver of the own vehicle <NUM> does not grasp the specific portions 35P of the steering wheel <NUM> with both hands, the vehicle collision avoidance assist apparatus <NUM> determines that the driver of the own vehicle <NUM> does not have the collision self-avoidance probability.

When the vehicle collision avoidance assist apparatus <NUM> determines that (i) the driver of the own vehicle <NUM> has the collision self-avoidance probability, based on the driver's consciousness state and (ii) the driver of the own vehicle <NUM> has the collision self-avoidance probability, based on the driver's steering wheel grasping state, the vehicle collision avoidance assist apparatus <NUM> sets the collision determination time TTCth to a first time TTC_1. In this embodiment, the first time TTC_1 is set to a standard time. Thus, when the collision determination time TTCth is set to the first time TTC_1, the forcibly steering start timing Ts_steer is a standard timing.

On the other hand, when the vehicle collision avoidance assist apparatus <NUM> determines that (i) the driver of the own vehicle <NUM> has the collision self-avoidance probability, based on the driver's consciousness state, but (ii) the driver of the own vehicle <NUM> does not have the collision self-avoidance probability, based on the driver's steering wheel grasping state, the vehicle collision avoidance assist apparatus <NUM> sets the collision determination time TTCth to a second time TTC_2. The second time TTC_2 is set to a time longer than the first time TTC_1. Thus, when the collision determination time TTCth is set to the second time TTC_2, the forcibly steering start timing Ts_steer is a timing earlier than the forcibly steering start timing Ts_steer realized when the collision determination time TTCth is set to the first time TTC_1.

Further, when the vehicle collision avoidance assist apparatus <NUM> determines that the driver of the own vehicle <NUM> does not have the collision self-avoidance probability, based on the driver's consciousness state, the vehicle collision avoidance assist apparatus <NUM> sets the collision determination time TTCth to a third time TTC_3, independently of whether the driver of the own vehicle <NUM> has the collision self-avoidance probability, based on the driver's steering wheel grasping state. The third time TTC_3 is set to a time longer than the second time TTC_2. Thus, when the collision determination time TTCth is set to the third time TTC_3, the forcibly steering start timing Ts_steer is a timing earlier than the forcibly steering start timing Ts_steer realized when the collision determination time TTCth is set to the second time TTC_2.

The summary of the operations of the vehicle collision avoidance assist apparatus <NUM> has been described. With the vehicle collision avoidance assist apparatus <NUM>, the execution of the forcibly steering control is started at a timing, depending on the probability that the collision of the own vehicle <NUM> with the forward object <NUM> can be avoided by the steering wheel operation carried out by the driver of the own vehicle <NUM>. Thus, the execution of the forcibly steering control is started at an appropriate timing without providing the driver of the own vehicle <NUM> with a discomfort.

It should be noted that the vehicle collision avoidance assist apparatus <NUM> may be configured to set the forcibly steering start timing Ts_steer such that the forcibly steering start timing Ts_steer set when the vehicle collision avoidance assist apparatus <NUM> determines that the driver of the own vehicle <NUM> does not have the collision self-avoidance probability, based on any one of the driver's consciousness state and the driver's steering wheel grasping state, is earlier than the forcibly steering start timing Ts_steer set when the vehicle collision avoidance assist apparatus <NUM> determines that the driver of the own vehicle <NUM> has the collision self-avoidance probability, based on both of the driver's consciousness state and the driver's steering wheel grasping state.

The vehicle collision avoidance assist apparatus <NUM> configured as such according to a first modified example of the embodiment of the invention sets the collision determination time TTCth to the first time TTC_1 when the vehicle collision avoidance assist apparatus <NUM> determines that the driver of the own vehicle <NUM> has the collision self-avoidance probability, based on both of the driver's consciousness state and the driver's steering wheel grasping state.

In the first modified example, the first time TTC_1 is the same as the first time TTC_1 of the embodiment described above. However, the first time TTC_1 of the first modified example may be different from the first time TTC_1 of the embodiment described above.

On the other hand, when the vehicle collision avoidance assist apparatus <NUM> according to the first modified example determines that the driver of the own vehicle <NUM> does not have the collision self-avoidance probability, based on any one of the driver's consciousness state and the driver's steering wheel grasping state, the vehicle collision avoidance assist apparatus <NUM> sets the collision determination time TTCth to the second time TTC_2.

In the first modified example, the second time TTC_2 is longer than the first time TTC_1. In this regard, the second time TTC_2 of the first modified example may be the same as or different from the second time TTC_2 of the embodiment described above. It should be noted that in the first modified example, the second time TTC_2 is the same as the third time TTC_3 of the embodiment described above.

Further, the vehicle collision avoidance assist apparatus <NUM> may be configured to set the forcibly steering start timing Ts_steer, depending on (i) whether the driver of the own vehicle <NUM> grasps the steering wheel <NUM>, (ii) whether the driver of the own vehicle <NUM> grasps the steering wheel <NUM> with both hands when the driver grasps the steering wheel <NUM>, and (iii) whether the driver of the own vehicle <NUM> grasps the specified portions 35P of the steering wheel <NUM> when the driver grasps the steering wheel <NUM>.

The vehicle collision avoidance assist apparatus <NUM> configured as such according to a second modified example of the embodiment of the invention sets the collision determination time TTCth to the first time TTC_1 when the vehicle collision avoidance assist apparatus <NUM> determines that (i) the driver of the own vehicle <NUM> has the collision self-avoidance probability, based on the driver's consciousness state and (ii) the driver of the own vehicle <NUM> grasps the specified portions 35P of the steering wheel <NUM> with both hands, i.e., the driver of the own vehicle <NUM> has the collision self-avoidance probability, based on the driver's steering wheel grasping state.

In the second modified example, the first time TTC_1 is the same as the first time TTC_1 of the embodiment described above. However, the first time TTC_1 of the second modified example may be different from the first time TTC_1 of the embodiment described above.

On the other hand, when the vehicle collision avoidance assist apparatus <NUM> according to the second modified example determines that (i) the driver of the own vehicle <NUM> has the collision self-avoidance probability, based on the driver's consciousness state and (ii) the driver of the own vehicle <NUM> grasps the steering wheel <NUM> with both hands, but (iii) the portions of the steering wheel <NUM> which the driver grasps are not the specified portions 35P of the steering wheel <NUM>, the vehicle collision avoidance assist apparatus <NUM> sets the collision determination time TTCth to the second time TTC_2.

In the second modified example, the second time TTC_2 is longer than the first time TTC_1. In this regard, the second time TTC_2 of the second modified example may be the same as or different from the second time TTC_2 of the embodiment described above.

Further, when the vehicle collision avoidance assist apparatus <NUM> according to the second modified example determines that (i) the driver of the own vehicle <NUM> has the collision self-avoidance probability, based on the driver's consciousness state and (ii) the driver of the own vehicle <NUM> grasps the steering wheel <NUM> with only one hand, but (iii) the portion of the steering wheel <NUM> which the driver grasps is the specified portion 35P of the steering wheel <NUM>, the vehicle collision avoidance assist apparatus <NUM> sets the collision determination time TTCth to the third time TTC_3.

In the second modified example, the third time TTC_3 is longer than the second time TTC_2. In this regard, the third time TTC_3 of the second modified example may be the same as or different from the third time TTC_3 of the embodiment described above.

Further, when the vehicle collision avoidance assist apparatus <NUM> according to the second modified example determines that (i) the driver of the own vehicle <NUM> has the collision self-avoidance probability, based on the driver's consciousness state and (ii) the driver of the own vehicle <NUM> does not grasp the steering wheel <NUM>, the vehicle collision avoidance assist apparatus <NUM> sets the collision determination time TTCth to a fourth time TTC_4.

In the second modified example, the fourth time TTC_4 is longer than the third time TTC_3.

Further, when the vehicle collision avoidance assist apparatus <NUM> according to the second modified example determines that the driver of the own vehicle <NUM> has the collision self-avoidance probability, based on the driver's consciousness state, the vehicle collision avoidance assist apparatus <NUM> sets the collision determination time TTCth to a fifth time TTC_5 independently of whether the driver of the own vehicle <NUM> has the collision self-avoidance probability, based on the driver's steering wheel grasping state.

In the second modified example, the fifth time TTC_5 is longer than the fourth time TTC_4. In particular, the fifth time TTC_5 of the second modified example is the same as the third time TTC_3 of the embodiment described above.

Further, the vehicle collision avoidance assist apparatus <NUM> may be configured to execute a forcibly braking control in addition to or in place of executing the forcibly steering control. The forcibly braking control is a control of forcibly applying the braking force to the own vehicle <NUM> and stopping the own vehicle <NUM> before the forward object <NUM> to avoid the collision of the own vehicle <NUM> with the forward object <NUM>.

Also in this case, as shown in <FIG>, when (i) the own vehicle <NUM> approaches the forward object <NUM> without the collision avoidance steering wheel operation carried out by the driver of the own vehicle <NUM>, and (ii) the predicted reaching time TTC decreases to the collision determination time TTCth, the vehicle collision avoidance assist apparatus <NUM> determines that the own vehicle <NUM> collides with the forward object <NUM> if the own vehicle <NUM> continues moving, keeping the current driving state of the own vehicle <NUM>. When the vehicle collision avoidance assist apparatus <NUM> determines so, the vehicle collision avoidance assist apparatus <NUM> determines that (i) a condition of executing the forcibly braking control, i.e., a forcibly braking execution condition Cs_brake becomes satisfied and (ii) a forcibly braking start timing Ts_brake has come.

When the vehicle collision avoidance assist apparatus <NUM> determines that the forcibly braking start timing Ts_brake has come, the vehicle collision avoidance assist apparatus <NUM> sets a deceleration value of the own vehicle <NUM> necessary to stop the own vehicle <NUM> before the forward object <NUM> as a target deceleration value Gtgt and starts executing the forcibly braking control of controlling the braking force applied to the own vehicle <NUM> so as to decelerate the own vehicle <NUM> at the target deceleration value Gtgt.

Thereby, the own vehicle <NUM> starts to be braked as shown in <FIG> and then, is stopped before the forward object <NUM> as shown in <FIG>. Thereby, a collision of the own vehicle <NUM> with the forward object <NUM> is avoided. When the vehicle collision avoidance assist apparatus <NUM> stops the own vehicle <NUM> before the forward object <NUM>, the vehicle collision avoidance assist apparatus <NUM> terminates executing the forcibly braking control.

When the vehicle collision avoidance assist apparatus <NUM> is configured to execute the forcibly braking control as described above, the vehicle collision avoidance assist apparatus <NUM> may be configured to adjust the start timing of starting executing the forcibly braking control by setting the collision determination time TTCth, depending on the collision self-avoidance probability as described above.

That is, when the vehicle collision avoidance assist apparatus <NUM> is configured to (i) execute the forcibly steering control and/or the forcibly braking control as the collision avoidance control for avoiding the collision of the own vehicle <NUM> with the forward object <NUM> and (ii) determines that the driver of the own vehicle <NUM> does not have the collision self-avoidance probability, the vehicle collision avoidance assist apparatus <NUM> may be configured to set the start timing of starting executing the collision avoidance control to a timing earlier than a timing set when the vehicle collision avoidance assist apparatus <NUM> determines that that the driver of the own vehicle <NUM> has the collision self-avoidance probability.

Next, specific operations of the vehicle collision avoidance assist apparatus <NUM> will be described. The CPU of the ECU <NUM> of the vehicle collision avoidance assist apparatus <NUM> according to the embodiment of the invention is configured or programmed to execute a routine shown in <FIG> with a predetermined calculation cycle. Thus, at a predetermined timing, the CPU starts executing a process from a step <NUM> of the routine shown in <FIG> and proceeds with the process to a step <NUM> to determine whether the driver of the own vehicle <NUM> is conscious. That is, the CPU determines whether the driver of the own vehicle <NUM> has the collision self-avoidance probability, based on the driver's consciousness state.

When the CPU determines "Yes" at the step <NUM>, the CPU proceeds with the process to a step <NUM> to determine whether the driver's steering wheel grasping state of the own vehicle <NUM> corresponds to a specified state, i.e., a state that the driver grasps the specified portions 35P of the steering wheel <NUM> with both hands. That is, the CPU determines whether the driver of the own vehicle <NUM> has the collision self-avoidance probability, based on the steering wheel grasping state.

When the CPU determines "Yes" at the step <NUM>, the CPU proceeds with the process to a step <NUM> to set the first time TTC_1 as the collision determination time TTCth. Next, the CPU proceeds with the process to a step <NUM> to terminate executing this routine once.

On the other hand, when the CPU determines "No" at the step <NUM>, the CPU proceeds with the process to a step <NUM> to set the second time TTC_2 as the collision determination time TTCth. Next, the CPU proceeds with the process to the step <NUM> to terminate executing this routine once.

Further, when the CPU determines "No" at the step <NUM>, the CPU proceeds with the process to a step <NUM> to set the third time TTC_3 as the collision determination time TTCth. Next, the CPU proceeds with the process to the step <NUM> to terminate executing this routine once.

Further, the CPU of the ECU <NUM> of the vehicle collision avoidance assist apparatus <NUM> according to the first modified example is configured or programmed to execute a routine shown in <FIG> with the predetermined calculation cycle. Thus, at a predetermined timing, the CPU starts executing a process from a step <NUM> of the routine shown in <FIG> and proceeds with the process to a step <NUM> to determine whether the driver of the own vehicle <NUM> is conscious. That is, the CPU determines whether the driver of the own vehicle <NUM> has the collision self-avoidance probability, based on the driver's consciousness state.

When the CPU determines "Yes" at the step <NUM>, the CPU proceeds with the process to a step <NUM> to determine whether the driver's steering wheel grasping state of the own vehicle <NUM> corresponds to the specified state, i.e., the state that the driver grasps the specified portions 35P of the steering wheel <NUM> with both hands. That is, the CPU determines whether the driver of the own vehicle <NUM> has the collision self-avoidance probability, based on the steering wheel grasping state.

Also, when the CPU determines "No" at the step <NUM>, the CPU proceeds with the process to the step <NUM> to set the second time TTC_2 as the collision determination time TTCth. Next, the CPU proceeds with the process to the step <NUM> to terminate executing this routine once.

Further, the CPU of the ECU <NUM> of the vehicle collision avoidance assist apparatus <NUM> according to the second modified example is configured or programmed to execute a routine shown in <FIG> with the predetermined calculation cycle. Thus, at a predetermined timing, the CPU starts executing a process from a step <NUM> of the routine shown in <FIG> and proceeds with the process to a step <NUM> to determine whether the driver of the own vehicle <NUM> is conscious. That is, the CPU determines whether the driver of the own vehicle <NUM> has the collision self-avoidance probability, based on the driver's consciousness state.

When the CPU determines "Yes" at the step <NUM>, the CPU proceeds with the process to a step <NUM> to determine whether a grasping level Lv corresponds to a first level Lv_1. The first level Lv_1 is a level that the driver of the own vehicle <NUM> grasps the specified portions 35P of the steering wheel <NUM> with both hands.

On the other hand, when the CPU determines "No" at the step <NUM>, the CPU proceeds with the process to a step <NUM> to determine whether the grasping level Lv corresponds to a second level Lv_2. The second level Lv_2 is a level that the driver of the own vehicle <NUM> grasps the steering wheel <NUM> with both hands, but the portions of the steering wheel <NUM> which the driver grasps are not the specified portions 35P of the steering wheel <NUM>.

When the CPU determines "Yes" at the step <NUM>, the CPU proceeds with the process to a step <NUM> to set the second time TTC_2 as the collision determination time TTCth. Next, the CPU proceeds with the process to the step <NUM> to terminate executing this routine once.

On the other hand, when the CPU determines "No" at the step <NUM>, the CPU proceeds with the process to a step <NUM> to determine whether the grasping level Lv corresponds to a third level Lv_3. The third level Lv_3 is a level that the driver of the own vehicle <NUM> grasps the steering wheel <NUM> with only one hand, but the portion of the steering wheel <NUM> which the driver grasps is the specified portion 35P of the steering wheel <NUM>.

When the CPU determines "Yes" at the step <NUM>, the CPU proceeds with the process to a step <NUM> to set the third time TTC_3 as the collision determination time TTCth. Next, the CPU proceeds with the process to the step <NUM> to terminate executing this routine once.

When the CPU determines "No" at the step <NUM>, the CPU proceeds with the process to a step <NUM> to set the fourth time TTC_4 as the collision determination time TTCth. Next, the CPU proceeds with the process to the step <NUM> to terminate executing this routine once.

When the CPU determines "No" at the step <NUM>, the CPU proceeds with the process to a step <NUM> to set the fifth time TTC_5 as the collision determination time TTCth. Next, the CPU proceeds with the process to the step <NUM> to terminate executing this routine once.

In addition, the CPU is configured or programmed to execute a routine shown in <FIG> with the predetermined calculation cycle. Thus, at a predetermined timing, the CPU starts executing a process from a step <NUM> of the routine shown in <FIG> and proceeds with the process to a step <NUM> to determine whether the avoidance route acquisition condition Croute and the forcibly steering start determination condition Cd_steer are satisfied. In particular, the CPU determines whether the object distance D200 is equal to or shorter than the collision probability determination distance Dth.

When the CPU determines "Yes" at the step <NUM>, the CPU proceeds with the process to a step <NUM> to acquire the avoidance route R. Next, the CPU proceeds with the process to a step <NUM> to acquire the predicted reaching time TTC. Next, the CPU proceeds with the process to a step <NUM> to determine whether the forcibly steering execution condition Cs_steer is satisfied. In particular, the CPU determines whether the predicted reaching time TTC is equal to or shorter than the collision determination time TTCth.

When the CPU determines "Yes" at the step <NUM>, the CPU proceeds with the process to a step <NUM> to determine whether the CPU has acquired the avoidance route R.

When the CPU determines "Yes" at the step <NUM>, the CPU proceeds with the process to a step <NUM> to set the acquired avoidance route R as the target avoidance route Rtgt. Next, the CPU proceeds with the process to a step <NUM> to execute the forcibly steering control. Next, the CPU proceeds with the process to a step <NUM> to terminate executing this routine once.

On the other hand, when the CPU determines "No" at the step <NUM>, the CPU proceeds with the process to the step <NUM> to terminate executing this routine once. In this case, the forcibly steering control is not executed.

Further, when the CPU determines "No" at the step <NUM> or the step <NUM>, the CPU proceeds with the process to the step <NUM> to terminate executing this routine once. Also, in this case, the forcibly steering control is not executed.

It should be noted that when the vehicle collision avoidance assist apparatus <NUM> is configured to execute the forcibly braking control in place of executing the forcibly steering control, the CPU is configured to execute a routine shown in <FIG> with the predetermined calculation cycle. Thus, at a predetermined timing, the CPU starts executing a process from a step <NUM> of the routine shown in <FIG> and proceeds with the process to a step <NUM> to determine whether a forcibly braking start timing determination condition is satisfied. In particular, the CPU determines whether the object distance D200 is equal to or shorter than the collision probability determination distance Dth.

When the CPU determines "Yes" at the step <NUM>, the CPU proceeds with the process to a step <NUM> to acquire the predicted reaching time TTC. Next, the CPU proceeds with the process to a step <NUM> to determine whether the forcibly braking execution condition Cs_brake is satisfied. In particular, the CPU determines whether the predicted reaching time TTC is equal to or shorter than the collision determination time TTCth.

When the CPU determines "Yes" at the step <NUM>, the CPU proceeds with the process to a step <NUM> to acquire the target deceleration value Gtgt. Next, the CPU proceeds with the process to a step <NUM> to execute the forcibly braking control. Next, the CPU proceeds with the process to a step <NUM> to terminate executing this routine once.

On the other hand, when the CPU determines "No" at the step <NUM>, the CPU proceeds with the process to the step <NUM> to terminate executing this routine once. In this case, the forcibly braking control is not executed.

Further, when the CPU determines "No" at the step <NUM>, the CPU proceeds with the process to the step <NUM> to terminate executing this routine once.

The specific operations of the vehicle collision avoidance assist apparatus <NUM> have been described.

Claim 1:
A vehicle collision avoidance assist apparatus (<NUM>) comprises an electronic control unit (<NUM>) configured to execute a collision avoidance control for avoiding a collision of an own vehicle (<NUM>) with an object (<NUM>) ahead of the own vehicle (<NUM>),
wherein the electronic control unit (<NUM>) is configured to:
acquire an object distance (D200) which is a distance between the object (<NUM>) and the own vehicle (<NUM>);
acquire a relative speed (ΔV200) which is a speed of the own vehicle (<NUM>) with respect to the object (<NUM>);
acquire a predicted reaching time (TTC) by dividing the object distance (D200) by the relative speed (ΔV200);
determine whether a driver of the own vehicle (<NUM>) has a collision self-avoidance probability that the driver of the own vehicle (<NUM>) can avoid a collision of the own vehicle (<NUM>) with the object (<NUM>) ahead of the own vehicle (<NUM>) by carrying out a driving operation to the own vehicle (<NUM>); and
when the electronic control unit (<NUM>) determines that the driver of the own vehicle (<NUM>) does not have the collision self-avoidance probability, set a start timing to start executing the collision avoidance control to a timing earlier than the start timing set when the electronic control unit (<NUM>) determines that the driver of the own vehicle (<NUM>) has the collision self-avoidance probability;
the vehicle collision avoidance assist apparatus (<NUM>) being characterized in that the electronic control unit (<NUM>) is configured to set the start timing to a timing when the predicted reaching time (TTC) decreases to a collision determination time (TTCth), and to advance the start timing, when the electronic control unit (<NUM>) determines that the driver of the own vehicle (<NUM>) does not have the collision self-avoidance probability, by increasing the collision determination time (TTCth).