JP4442520B2 - Course estimation device for vehicle - Google Patents

Description

  The present invention relates to a vehicle route estimation apparatus.

  Conventionally, a technique for determining the possibility of collision between the own vehicle and an obstacle has been proposed (see, for example, Patent Document 1). According to the technique disclosed in Patent Document 1, a device that calculates an estimated travel locus estimated that a vehicle travels from a steering angle or the like, and processes a road condition image such as a white line or an object photographed by a camera. Using an image processing device and a radar device that detects an object in front of the vehicle, the estimated traveling locus, the traveling path, and the object are grasped, and an obstacle exists in the estimated traveling locus, and the obstacle Is present on the travel road, it is determined that there is a greater danger in the vehicle than when there is an obstacle in the travel path but no obstacle in the estimated travel path.

Also, if the vehicle is located near the curve entrance, it is highly probable that the estimated travel locus will not follow the travel path due to the time delay of the vehicle behavior, and the probability that the vehicle will travel on the estimated travel locus is low. Even if there is no dangerous obstacle on the travel locus, if there is a dangerous obstacle on the traveling road, the risk of colliding with the obstacle on the traveling road becomes high. Therefore, in this prior art, it is determined whether or not the vehicle is located in the vicinity of the curve entrance / exit of the traveling road, and the degree of risk is determined based on the determination result.
JP 2004-110394 A

  Compared to the above-described conventional technology for determining the possibility of collision based on the estimated traveling locus of the own vehicle and the traveling path, the relative coordinate system with the own vehicle position as the origin is set to the own vehicle, and the object in this relative coordinate system There is a method of determining the possibility of collision by estimating the path of an object from the past position history of the object (past position history) (hereinafter referred to as relative coordinate system path estimation). The determination method based on the relative coordinate system route estimation uses a camera or an image processing device for capturing an image of a road situation as in the prior art in order to determine the possibility of a collision without grasping the traveling route of the host vehicle. There is no need to prepare.

  However, in a situation where the steering angle of the host vehicle changes suddenly, the change in the steering angle is reflected in the estimated course of the object, so that the estimation accuracy is poor. Such a situation is likely to occur, for example, when the own vehicle avoids an obstacle such as a parked vehicle or when the own vehicle enters a curve with a small road radius from a straight road.

  For example, as shown in FIG. 6 (a), in the situation where the host vehicle enters a curve from a straight road, the host vehicle usually moves straight ahead to the front of the entrance of the curve. The past position history is arranged in the vertical direction. For this reason, the estimated course of the roadside object obtained from the past position history is directed to the origin of the relative coordinate system of the own vehicle.

  On the other hand, as shown in FIG. 6 (b), when the vehicle enters the curve, when the steering of the vehicle is operated, the roadside object is positioned on the left side in the traveling direction of the vehicle. The true path of the roadside object is as shown by the dotted line in FIG. However, since the estimated course of the roadside object is obtained from the past position history of the previous roadside object, it is difficult to reflect the temporary change in the position of the roadside object, and therefore reflected behind the estimated course of the roadside object. .

  Therefore, as shown in FIG. 6 (b), the estimated course of the roadside object when the steering is operated is not significantly different from the estimated course when approaching straight ahead before the entrance of the curve, and the relative coordinates of the own vehicle It comes to face the origin of the system. As a result, although the possibility of collision is low, it is erroneously determined that the possibility of collision is high.

  The present invention has been made in view of the above-described problems, and is a vehicle course that can perform highly accurate course estimation of an object ahead of the host vehicle even in a situation where the steering angle of the host vehicle suddenly changes. An object is to provide an estimation device.

In order to achieve the above object, a vehicle course estimation apparatus according to claim 1,
An object detection means for detecting an object existing in front of the own vehicle and outputting a relative position and a relative speed of the object with respect to the own vehicle;
First course estimation means for estimating a relative course of an object based on the vehicle based on a past position history indicating a past history of the relative position of the object;
Vehicle motion state detection means for detecting the motion state of the host vehicle;
Second course estimating means for estimating a relative course of the object based on the own vehicle based on the relative position of the object and the motion state of the own vehicle;
Absolute speed calculating means for calculating the absolute speed of the object from the relative speed of the object and the motion state of the own vehicle;
Determining means for determining a means to be used in estimating the course out of the first and second course estimating means based on the absolute velocity of the object,
The decision means is
Regarding the absolute speed of an object, a stationary speed range in which the object is determined to be a stationary object, a moving speed range in which the object is determined to be a moving object, and an intermediate speed range between the stationary speed range and the moving speed range It is divided into the speed range in advance,
If the absolute speed calculated by the absolute speed calculating means is included in the moving speed range, the first course estimating means is determined,
If the absolute speed calculated by the absolute speed calculating means is included in the stationary speed range, the second speed estimating means is determined,
If the absolute speed calculated by the absolute speed calculation means is included in the intermediate speed range, the first and second course estimation means are determined,
The relative course of the object is estimated using the means determined by the determining means.

  By using the first course estimating means based on the past position history of the relative position of the object, it is possible to estimate the relative course of the object with reference to the own vehicle. However, this first course estimation means reflects the change in the steering angle with a delay in the estimated course of the object in a transient situation such as a situation where the steering angle of the host vehicle suddenly changes. The estimation accuracy is inferior.

  For example, as shown in FIG. 6 (b), when the host vehicle enters the curve, if the steering of the host vehicle is operated, the roadside object is positioned on the left side in the traveling direction of the host vehicle. The true path of the roadside object is as shown by the dotted line in FIG. However, as described above, since the estimated course of the roadside object is obtained from the past position history of the previous roadside object, it is difficult to reflect a temporary change in the position of the roadside object. Reflected late. Note that this phenomenon frequently occurs for a stationary object having a high relative speed with the host vehicle, such as a roadside object.

  Here, if the object is a stationary object (in other words, an object having an absolute velocity of zero), the relative motion of the object with respect to the own vehicle is the relative motion of the own vehicle with respect to the object. The opposite is true. Further, the motion state of the own vehicle can be grasped from the vehicle speed and the steering angle (or the yaw rate) with little delay in time. Therefore, if the relative course of the stationary object can be estimated based on the motion state of the own vehicle, it is possible to estimate the course with high accuracy with little time delay.

  The present invention focuses on this point, and includes a first course estimation unit based on the past position history of the object, and a second course estimation unit based on the relative position of the object and the motion state of the host vehicle. Based on the absolute velocity, a means to be used when estimating the course is determined, and the relative path of the object is estimated using the determined means.

  Accordingly, for example, the relative course of the object having an absolute speed of zero is estimated based on the movement state of the own vehicle with little time delay by the second course estimation unit, and therefore FIG. It will be close to the true path, as shown by the dotted trajectory. As a result, it is possible to estimate the course with high accuracy.

In addition, this makes it possible to use the first and second route estimation means properly depending on whether the absolute velocity of the object is included in the stationary velocity region or the moving velocity region. Note that when the absolute velocity of the object is near the boundary between the stationary velocity region and the moving velocity region, the first and second estimated routes are estimated from either the first or second route estimating means alone. In many cases, an intermediate route between two estimated routes estimated by each of the route estimation means is close to a true route.

Therefore, in the vehicle estimation apparatus according to claim 1, when the absolute speed of the object is included in the intermediate speed range, the final object estimation is performed from the two paths estimated by the first and second path estimation means. We estimate the course.

According to a second aspect of the present invention, when the determining means determines the first and second route estimating means, the estimation result of the first and second route estimating means corresponds to the level of the absolute speed. Weight adding means for adding the weights,
The relative course of the object is finally estimated from the estimation results of the first and second course estimation means to which the weight is added by the weight addition means.

  Thereby, when the absolute speed of the object is included in the intermediate speed range, a weight corresponding to the level of the absolute speed is added to the two paths estimated by the first and second path estimation means, and finally The path of a simple object can be estimated.

According to the vehicle course estimation apparatus according to claim 3 , the vehicle motion state detection means is a motion state around the vertical direction of the host vehicle from at least one of the steering angle and yaw rate of the host vehicle as the motion state of the host vehicle. Detect
The second course estimating means is:
A turning radius estimating means for estimating a turning radius of the own vehicle from a state of motion around the vertical direction of the own vehicle;
A curve based on the relative position of the object and calculated from the relative position of the object and the turning radius of the host vehicle is estimated as a relative course of the object.

  As shown in FIG. 5, the relative path of the stationary object with respect to the own vehicle is a point P (x1, z1) indicating the current relative position of the stationary object when the own vehicle turns with the turning radius R (estimated R). Is indicated by an arc of radius R1 passing through. Further, the direction of the course is the direction opposite to the turning direction of the own vehicle, that is, the direction from the point P to the point Q or the point R. Therefore, from the current relative position of the object and the turning radius of the host vehicle, it is possible to estimate the trajectory of the curve indicated by the arc with the current relative position of the object as a base point as the relative course of the object.

According to the vehicle course estimation apparatus according to claim 4 , the vehicle motion state detection means outputs an output of at least one of a steering sensor that detects the steering angle of the host vehicle and a yaw rate sensor that detects the yaw rate of the host vehicle. To detect the state of motion of the vehicle around the vertical direction,
The second course estimating means is characterized in that after the neutral point learning of the steering sensor and the yaw rate sensor is finished, the estimation of the relative course of the object is started.

  In this way, the vehicle motion state detection means detects the motion state of the vehicle around the vertical direction from the outputs of the steering sensor and the yaw rate sensor, and therefore the accuracy of these sensor outputs corresponds to the accuracy of estimating the relative path of the object. Influence. By the way, the steering sensor, the yaw rate sensor, and the like learn the neutral point when the vehicle travels while maintaining the straight traveling state. It cannot be detected with high accuracy, and the relative path of the object cannot be estimated with high accuracy. Therefore, by starting the estimation of the relative course of the object after the neutral point learning of the steering sensor or the yaw rate sensor is completed, it is possible to prevent the accuracy of the estimated course from being lowered.

According to a fifth aspect of the present invention, there is provided a vehicle course estimation device that can determine whether or not the host vehicle and the object collide based on the relative course of the object estimated using the means determined by the determination means. It is characterized by comprising sex determining means. Thereby, the possibility that the own vehicle and the object collide can be determined based on the relative course of the object.

According to a sixth aspect of the present invention, there is provided a vehicle route estimation apparatus including a warning generation unit that generates a warning to a driver of the own vehicle according to the degree of the collision possibility determined by the collision possibility determination unit. And Thereby, when there is a possibility of collision between the host vehicle and the object, it is possible to notify the driver of the host vehicle that there is a possibility of collision.

The vehicle route estimation apparatus according to claim 7 is a driving support that performs driving support control for supporting driving of the driver of the own vehicle according to a degree of possibility of collision determined by the collision possibility determination unit. Control means is provided. Thereby, when there is a possibility that the host vehicle and the object collide, the driving support control can be executed so as to reduce damage at the time of the collision with the object or to avoid the collision.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, a case where the vehicle route estimation apparatus of the present invention is applied as one function of a driving support system will be described. In FIG. 1, the whole structure of the driving assistance system of this embodiment is shown. The driving support system is composed of various sensors such as the laser radar 1 and the electronic control units of the engine ECU 3, the brake ECU 4 and the meter ECU 17 with the driving support control ECU 2 as the center.

  The laser radar 1 is mounted in the vicinity of the front grille at the front of the vehicle body of the host vehicle, and inputs the current vehicle speed of the host vehicle and the turning radius R (estimated R) of the host vehicle from the driving support control ECU 2 and transmits laser light to the host vehicle. By irradiating a predetermined range in front, the relative position, relative speed, and size (width, height, etc.) of the reflecting object that reflects the laser light are detected.

  Here, as shown in FIG. 5, the relative position of an object that is a reflective object is a relative coordinate system in which the own vehicle position is the origin, the left and right direction of the own vehicle is the X axis, and the front and rear direction of the own vehicle is the Z axis. When set, the position in the relative coordinate system (for example, the point P (x1, z1), etc.) is shown. The relative speed of the object indicates the speed in the direction of each coordinate axis. The object information composed of the detection result is converted into an electric signal and then output to the driving support control ECU 2. As described above, the object is not limited to detecting an object using laser light, but may be an object detecting an object in front of the host vehicle using radio waves such as millimeter waves and microwaves.

  The driving support control ECU 2 inputs the current vehicle speed of the host vehicle, the steering angle of the host vehicle, the yaw rate of the host vehicle, the target inter-vehicle time with the preceding vehicle existing ahead of the host vehicle, and the control state information of the engine ECU 3 output from the engine ECU 3. At the same time, the object information from the laser radar 1 is input to execute ACC (Adaptive Cruise Control). When the target inter-vehicle distance (target inter-vehicle time) with the preceding vehicle is set, the vehicle travels within the set vehicle speed. The inter-vehicle distance control that maintains the inter-vehicle distance according to the speed, or the constant speed traveling control that maintains the set vehicle speed is performed when there is no preceding vehicle.

  Further, the relative course of the object detected by the laser radar sensor 1 with respect to the own vehicle is estimated, the possibility of collision between the own vehicle and the object is determined based on the estimated course, and the possibility of collision Depending on the degree of the possibility of collision, an alarm is issued to the driver of the vehicle, damage caused by collision with an object is reduced, or a collision is Driving support control is performed to assist the driver's driving so as to avoid it. The driving support control by the driving support control ECU 2 will be described in detail later.

  The driving support control ECU 2 executes the ACC and the driving support control, and generates a target acceleration to be generated in the host vehicle, a fuel cut request for generating the target acceleration by the host vehicle, an overdrive (OD) cut request, Each request information of the downshift request and the brake request is output to the engine ECU 3, and an alarm request for alerting the driver and display data of the alarm display are output to the engine ECU 3.

  The engine ECU 3 is connected to the driving support control ECU 2, brake ECU 4, accelerator pedal sensor 5, vehicle speed sensor 6, brake SW 7, cruise control SW 8, cruise main SW 9, throttle actuator (ACT) 10, transmission 11, and meter ECU 17. .

  The accelerator pedal sensor 5 detects the amount of depression of the accelerator pedal of the host vehicle, and the vehicle speed sensor 6 detects the current vehicle speed of the host vehicle and outputs the detection result to the engine ECU 3. The brake SW 7 outputs the state of the brake pedal (the state where the pedal is depressed: ON / the state where the pedal is not depressed: OFF) to the engine ECU 3. The cruise control SW 8 outputs the state (ON / OFF) of various control switches (set SW, resume SW, cancel SW, tap SW, etc.) of the ACC to the engine ECU 3. The cruise main SW 9 is a switch for enabling start of constant speed traveling control and inter-vehicle distance control.

  Here, the set SW takes in the vehicle speed (current vehicle speed) at that time by operating this, and stores this vehicle speed as the set vehicle speed. Further, when the set vehicle speed is taken in, constant speed traveling control is performed. The resume SW is for returning the vehicle speed of the host vehicle from the current vehicle speed to the set vehicle speed when pressed when the set vehicle speed is stored in a state where constant speed traveling control is not being performed. The cancel SW cancels the constant speed traveling control and the inter-vehicle distance control that are being executed, and the cancel process is executed by pressing the cancel SW. The tap SW is for setting the inter-vehicle distance with the preceding vehicle, and can be set only within a predetermined range according to the user's preference.

  The throttle actuator (ACT) 10 controls the opening degree of the throttle valve according to an instruction from the engine ECU 3, and the transmission 11 controls the transmission gear ratio according to the instruction from the engine ECU 3.

  The engine ECU 3 inputs various information from the driving support control ECU 2, the brake ECU 4, and the meter ECU 17, and outputs various information on the alarm request, the brake request, and the target acceleration to the brake ECU 4. Output display data. Further, a command signal for causing the acceleration generated in the own vehicle to become the target acceleration is output to the throttle ACT 10 and the transmission 11.

  The brake ECU 4 is connected to a steering sensor 12, a yaw rate sensor 13, a wheel speed sensor 14, an alarm buzzer 15, and a brake actuator (ACT) 16. The steering sensor 12 is a sensor that detects a steering angle of the steering of the host vehicle, and outputs information on the detected steering angle to the brake ECU 4. The yaw rate sensor 13 is a sensor that detects an angular velocity around the vertical direction of the host vehicle, and outputs detected yaw rate information to the brake ECU 4.

  The wheel speed sensor 14 is a sensor that detects the wheel speed of each wheel of the host vehicle, and outputs the detected wheel speed of each wheel to the brake ECU 4. The brake ECU 4 inputs various alarm request information, brake request, and target acceleration information from the engine ECU 3 and detection results from the steering sensor 12, the yaw rate sensor 13, and the wheel speed sensor 14 to alert the alarm buzzer 15. An instruction signal for generation is output, or an instruction signal for operating the brake to the brake ACT 16 is output. Further, each information of the steering angle and the yaw rate is output to the engine ECU 3.

  Meter ECU17 inputs the display data from engine ECU3, and performs display control of the meter and display screen which were provided in the instrument panel of the own vehicle. In addition, operation information of various in-vehicle devices acquired via an in-vehicle LAN (not shown) is output to the engine ECU 3.

  Next, the characteristic part of the driving assistance system of this embodiment is demonstrated. When the driving assistance control ECU 2 estimates the course of the object with respect to the own vehicle in the driving assistance control, as shown in FIG. 4, the driving assistance control ECU 2 is based on the past position history indicating the past history of the relative position of the object with respect to the own vehicle. A method for estimating the relative course of an object with reference to the host vehicle and a method for estimating the relative path of the object with reference to the host vehicle based on the movement state of the host vehicle such as the relative position of the object and the steering angle. Different methods are used depending on the absolute velocity of the object.

  That is, the relative course of the object can be estimated by the course estimation based on the past position history of the object. However, this course estimation is performed in a transitional situation such as a situation where the steering angle of the host vehicle suddenly changes. Will be inferior.

  For example, as shown in FIG. 6 (b), when the host vehicle enters the curve, if the steering of the host vehicle is operated, the roadside object is positioned on the left side in the traveling direction of the host vehicle. The true path of the roadside object is as shown by the dotted line in FIG. However, as described above, since the estimated course of the roadside object is obtained from the past position history of the previous roadside object, it is difficult to reflect a temporary change in the position of the roadside object. Reflected late. Note that this phenomenon frequently occurs for a stationary object having a high relative speed with the host vehicle, such as a roadside object.

  Here, if the object is a stationary object (in other words, an object having an absolute speed of zero), the relative motion state of the object with respect to the own vehicle is relative to the own vehicle with respect to the object. It is in the opposite relation to the state of exercise. Further, the motion state of the own vehicle can be grasped from the vehicle speed and the steering angle (or the yaw rate) with little delay in time.

  The driving support system according to the present embodiment pays attention to this point. Regarding the course estimation method based on the past position history of the object and the course estimation method based on the relative position of the object and the motion state of the own vehicle, the absolute velocity of the object is described. Based on this, a method to be used in estimating the course is determined, and the relative course of the object is estimated using the determined course estimation method.

  Thus, for example, the relative course of an object having an absolute speed of zero is estimated from the movement state of the own vehicle with little time delay by the course estimation method based on the relative position of the object and the movement state of the own vehicle. Therefore, it becomes close to the true course as shown by the dotted locus shown in FIG. As a result, it is possible to estimate the course with high accuracy.

  Next, the driving support control process executed by the driving support control ECU will be described with reference to the flowcharts shown in FIGS. Here, an example in which the course of one object is estimated will be described. If there are a plurality of objects, the course of each object is estimated.

  In step (hereinafter referred to as S) 10 shown in FIG. 2, initial setting of various ECUs and various sensors is performed. This initial setting includes neutral point learning of the steering sensor 12 and the yaw rate sensor 13, and the neutral point learning is completed, and the process proceeds to the subsequent stage.

  That is, in the course estimation method based on the absolute speed of the object, the relative position of the object, and the motion state of the host vehicle, it is calculated from the motion state of the host vehicle around the vertical direction. The accuracy of the sensor output from the steering sensor 12 and the yaw rate sensor 13 for detecting the influence on the absolute speed and the estimation accuracy of the course. Since the steering sensor 12, the yaw rate sensor 13, and the like learn the neutral point when the vehicle travels while maintaining a straight traveling state, the absolute speed of the object and the vehicle are not affected unless the neutral point learning is completed. The movement state around the vertical direction cannot be detected with high accuracy, and the course cannot be estimated with high accuracy.

  Therefore, after the neutral point learning of the steering sensor 12 and the yaw rate sensor 13 is completed, the estimation accuracy of the course can be prevented from being lowered by starting the subsequent absolute speed calculation and the course estimation calculation process.

  In S20, an object course estimation calculation process is executed. The course estimation calculation process will be described with reference to the flowchart shown in FIG. In S110 shown in FIG. 3, it is determined from the object information output from the laser radar 1 whether or not an object exists in front of the host vehicle. If the determination is affirmative, the process proceeds to S120. If the determination is negative, the process ends.

  In S120, the relative position of the object is referred to from the object information, and this relative position is added to the previously stored past position history and stored. In S130, the absolute speed of the object is calculated from the relative motion state of the object based on the subject vehicle and the motion state of the subject vehicle. That is, it is calculated from the relative speed of the object in the X-axis and Z-axis directions, the current vehicle speed of the host vehicle, and the yaw rate.

  In S140, a course estimation method to be used when estimating the course of the object is determined based on the magnitude of the absolute velocity of the object calculated in S130. That is, it is determined whether to estimate by the course estimation method based on the past position history of the object or to estimate by the course estimation method based on the relative position of the object and the motion state of the host vehicle.

  In S140, the absolute velocity of the object is divided in advance into a stationary velocity region in which the object is determined to be a stationary object and a moving velocity region in which the object is determined to be a moving object. If the absolute speed of the object is included in the moving speed range, the path estimation method to be used when estimating the path of the object is determined as the path estimation method based on the past position history of the object, and the absolute speed of the object is When it is included in the stationary speed range, the course estimation method is determined based on the relative position of the object and the motion state of the own vehicle. Accordingly, the route estimation method can be properly used depending on whether the absolute velocity of the object is included in the stationary velocity region or the moving velocity region.

  In S150, it is determined whether or not the course estimation method based on the past position history of the object has been determined. If the determination is affirmative, in S160, the relative course of the object is estimated based on the past position history of the object. On the other hand, if a negative determination is made, the process proceeds to S170. In S160, for example, the path of the object is estimated from the past position history of the object using a method such as a least square method.

  In S170, the course of the object is estimated from the relative position of the object and the motion state of the host vehicle. The target object in the course estimation method in S170 is a stationary object (or an object that can be regarded as being stationary). When there is a stationary object in front of the host vehicle, the path of the stationary object, that is, the subsequent relative movement based on the host vehicle is indicated as an arc by the current vehicle speed and the turning radius (estimated R) of the host vehicle. In S170, this arc is calculated as an approximate curve indicating the course of the stationary object. As shown in FIG. 5, the center of the circular arc is located on the center of rotation of the own vehicle, that is, on the rear wheel axle when the own vehicle is front wheel steered.

  Next, in FIG. 5, assuming that the current relative position of the stationary object is a point P (x1, z1), the radius R1 of the arc passing through this point P is expressed by the following equation. In the following formula, the distance from the origin of the XZ relative coordinate system to the rear wheel axle is d. R represents the turning radius of the host vehicle, and a value estimated from the steering angle and the yaw rate is used.

(Equation 1)
Arc radius R1 = √ {(R−x1) ² + (d + z1) ² }
The arc formula is shown by the following formula.

(Equation 2)
R1 ² = (x−R) ² + (z + d) ²
Here, when the formula of the arc radius R1 of Formula 1 is substituted into the formula of the arc of Formula 2, the following formula is obtained.

(Equation 3)
{√ {(R−x1) ² + (d + z1) ² }} ² = (x−R) ² + (z + d) ²
From Equation 3, xq of the point Q (xq, 0) that intersects the arc X-axis is expressed by the following equation. Note that the sign (±) of the following equation is reversed by the sign of R.

(Equation 4)
xq = R ± √ {(R−x1) ² + z1 ² − (2 × d × z1)}
Thus, the relative path of the stationary object with respect to the own vehicle is a radius passing through the point P (x1, z1) indicating the current relative position of the stationary object when the own vehicle turns with the turning radius R (estimated R). The direction of the course indicated by the arc of R1 indicates the direction opposite to the turning direction of the vehicle, that is, the direction of point Q or point R. Therefore, from the current relative position of the object and the turning radius of the host vehicle, a curve indicated by an arc having the current relative position of the object as a base point can be estimated as the relative course of the object. The possibility that the stationary object and the host vehicle collide can be determined based on the value indicated by xq calculated by Expression 4.

  When the course estimation calculation process shown in FIG. 3 is completed, in S30 shown in FIG. 2, it is determined whether or not an object existing ahead of the host vehicle collides with the host vehicle. For example, using the path estimated in S20 as a reference, a dangerous area having a size corresponding to the length of the distance to the object, the size of the relative speed of the object, the width of the vehicle, etc. is set on the relative coordinate system. Then, by comparing the danger area with the own vehicle position, the degree of possibility of collision between the object and the own vehicle (collision risk) is calculated. Thereby, the possibility that the own vehicle and the object collide can be determined based on the relative course of the object.

  In S40, for example, from the size (width, height) of the object detected by the laser radar 1, taking into account the appearance of the object, whether the vehicle is actually in contact with the vehicle, Identify an object that is uncertain based on whether it is a vehicle that may collide or cause damage, or whether the sensing of various sensors is in a normal state. exclude. Thereby, it is possible to suppress the occurrence of an unnecessary alarm or an erroneous alarm in the subsequent process, or to suppress the execution of an unnecessary control or an erroneous control.

  In S50, depending on the degree of possibility of collision determined in S30, an alarm is issued to the driver of the vehicle, damage caused by collision with an object is reduced, or collision is avoided. Or help the driver to drive.

  As described above, the driving support system according to the present embodiment is based on the level of the absolute speed of the object for the route estimation method based on the past position history of the object and the route estimation method based on the relative position of the object and the motion state of the host vehicle. Then, a method to be used in estimating the course is determined, and the relative course of the object is estimated using the determined course estimation method.

  Thus, for example, the relative course of an object having an absolute speed of zero is estimated from the movement state of the own vehicle with little time delay by the course estimation method based on the relative position of the object and the movement state of the own vehicle. Therefore, the estimated course is close to the true course. As a result, it is possible to estimate the course with high accuracy.

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

(Modification 1)
For example, the course estimation calculation process shown in FIG. 3 is based on whether the absolute speed of the object is included in the stationary speed range or the moving speed range, the path estimation method based on the past position history of the object, and the object The route estimation method based on the relative position and the motion state of the host vehicle is selectively used. When the absolute speed of the object is near the boundary between the stationary speed range and the moving speed range, either of the two route estimation methods is used. In many cases, an intermediate route between two routes estimated by each of the two route estimation methods is closer to a true route than a route estimated independently.

  So, for example, for the absolute speed of the object, set an intermediate speed range between the stationary speed range and the moving speed range near the boundary between the stationary speed range and the moving speed range, If the absolute speed of the object is included in the intermediate speed range by dividing it into three speed ranges, the intermediate speed range and the moving speed range, the path estimation method to be used when estimating the path of the object is Determine the course estimation method. Thus, when the absolute speed of the object is included in the intermediate speed range, the final path of the object is estimated from two different paths estimated by the two path estimation methods.

  In this case, a weight corresponding to the level of the absolute velocity of the object is added to the two course estimation results, and finally, the relative course of the object is determined from the course estimation result to which the weight is added. presume. As a result, when the absolute speed of the object is included in the intermediate speed range, weighting corresponding to the level of the absolute speed is added to the two estimated paths, so that the estimated path of the object closer to the true path is estimated. Can do.

(Modification 2)
In addition, the course estimation calculation process shown in FIG. 3 uses two course estimation methods depending on whether or not the object can be determined as a stationary object. If it is possible to identify what it is, it can be determined whether or not the object is a stationary object. For example, if an object in front of the vehicle can be identified as a roadside object such as a road sign, a guardrail, a delineator, a median strip, a traffic light, or a power pole, the object is fixedly laid on the road. Therefore, it can be determined that the object is stationary.

  Therefore, for example, when an image processing device or the like that captures a road situation ahead of the host vehicle and identifies an object ahead of the host vehicle is provided, the object present ahead of the host vehicle is a stationary object based on the identification result. It may be determined whether or not there is, and based on the determination result, the two course estimation methods may be used properly.

It is a block diagram which shows the whole structure of the driving assistance system of this embodiment. It is a flowchart which shows the flow of a driving assistance control process. It is a flowchart which shows the flow of a course estimation calculation process. It is a conceptual diagram of the course estimation method by the past position history of the object and the course estimation method by the steering angle. It is a figure which shows the course estimation method of a stationary object. (A) is a figure which shows the past position history and estimated course of a roadside object when the own vehicle goes straight ahead and approaches the curve, and (b) is the roadside when the own vehicle enters the curve. It is a figure which shows the difference with the true estimated course of a thing.

Explanation of symbols

1 Laser radar 2 Driving support control ECU
3 Engine ECU
4 Brake ECU
17 Meter ECU

Claims (7)

An object detection means for detecting an object existing in front of the own vehicle and outputting a relative position and a relative speed of the object with respect to the own vehicle;
First course estimation means for estimating a relative course of the object based on the vehicle based on a past position history indicating a past history of the relative position of the object;
Vehicle motion state detection means for detecting the motion state of the vehicle;
Second course estimating means for estimating a relative course of the object based on the host vehicle based on a relative position of the object and a motion state of the host vehicle;
Absolute speed calculating means for calculating the absolute speed of the object from the relative speed of the object and the motion state of the host vehicle;
Determining means for deciding a means to be used when estimating the course among the first and second course estimating means based on the absolute velocity of the object;
The determining means includes
Regarding the absolute speed of an object, a stationary speed range in which the object is determined to be a stationary object, a moving speed range in which the object is determined to be a moving object, and a speed between the stationary speed range and the moving speed range Previously divided into the intermediate speed range,
When the absolute speed calculated by the absolute speed calculation means is included in the moving speed range, the first course estimation means is determined,
When the absolute speed calculated by the absolute speed calculation means is included in the stationary speed range, the second course estimation means is determined,
When the absolute speed calculated by the absolute speed calculation means is included in the intermediate speed range, the first and second course estimation means are determined,
A vehicle course estimation apparatus for estimating a relative course of the object using means determined by the determination means. When the determining means determines the first and second course estimating means, a weight adding means for adding a weight corresponding to the level of the absolute speed to the estimation results of the first and second course estimating means. Prepared,
2. The vehicle according to claim 1, wherein the relative course of the object is finally estimated from the estimation results of the first and second course estimation means to which weighting is added by the weight addition means. A route estimation device. The vehicle movement state detection means detects a movement state around the vertical direction of the own vehicle from at least one of a steering angle of the own vehicle and a yaw rate as the movement state of the own vehicle,
The second course estimating means includes
A turning radius estimating means for estimating a turning radius of the own vehicle from a movement state around the vertical direction of the own vehicle;
3. The curve according to claim 1, wherein a curve calculated from the relative position of the object and the turning radius of the own vehicle and based on the relative position of the object is estimated as a relative course of the object. The vehicle course estimation apparatus according to the description. The vehicle motion state detection means includes a steering sensor that detects a steering angle of the host vehicle and an output of at least one sensor of a yaw rate sensor that detects the yaw rate of the host vehicle, and the motion state of the host vehicle about the vertical direction. Is to detect
4. The vehicle according to claim 3, wherein the second course estimating means starts estimation of a relative course of the object after neutral point learning of the steering sensor and the yaw rate sensor is completed. Course estimation device. And a collision possibility determining means for determining a possibility of collision between the host vehicle and the object based on a relative course of the object estimated using the means determined by the determining means. The course estimation device for a vehicle according to any one of claims 1 to 4. 6. The vehicle route estimation according to claim 5, further comprising alarm generation means for generating an alarm to a driver of the host vehicle according to the degree of possibility of collision determined by the collision possibility determination means. apparatus. The driving support control means for performing driving support control for supporting the driving of the driver of the host vehicle according to the degree of possibility of collision determined by the collision possibility determination means. 5. The vehicle route estimation apparatus according to 5.

Images