JP2017043272A - Monitoring device and monitoring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a monitoring device which can suitably determine whether or not an obstacle should be monitored according to behaviors of an own vehicle and the obstacle, and a monitoring method.SOLUTION: When a lateral position offset is larger than a prescribed threshold, a monitoring determination part determines that an obstacle should not be monitored, when the lateral position offset is smaller than the prescribed threshold and TTC is smaller than the prescribed threshold, determines that the obstacle should be monitored, when the lateral position offset is smaller than the prescribed threshold and the TTC is larger than the prescribed threshold, determines whether or not a collision prediction time is changed to a state smaller than the prescribed threshold from a state larger than the prescribed threshold, when the collision time is changed, determines that the obstacle should be monitored, and when not changed, determines that the obstacle should not be monitored.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a monitoring determination device and a monitoring determination method.

  In recent years, in the automobile industry, in order to ensure the safety of passengers, development of a driving support device that supports driving of a driver is in progress. As this type of device, a driving support device that avoids a collision between an own vehicle and an obstacle (for example, a preceding vehicle traveling in front of the traveling direction of the own vehicle) or reduces damage caused by the collision by automatic brake control. Has been proposed (see, for example, Patent Document 1).

  The driving support device disclosed in Patent Document 1 calculates a collision prediction time based on the distance and relative speed between the host vehicle and an obstacle measured by the radar device, and the collision prediction time is a predetermined time. When the time is shorter than that, driving support control such as an alarm or automatic brake is executed to notify that effect.

JP 2009-18721 A

  The automatic braking reduces the vehicle speed of the host vehicle and increases the distance between the host vehicle and the obstacle, which may increase the expected collision time. In such a case, the automatic brake is stopped because the automatic brake condition is not satisfied.

  If the operating conditions of the automatic brake are not satisfied due to the deceleration by the automatic brake, the conventional driving assistance device not only stops the automatic brake but also stops monitoring the speed and position of the obstacle. It was. However, the automatic brake operation condition may be satisfied again after the automatic brake is stopped, for example, when the host vehicle is reaccelerated or the obstacle is decelerated. Assuming such a situation, it is desirable not to stop monitoring the speed and position of an obstacle just because the obstacle once does not satisfy the operating condition of the automatic brake.

  Accordingly, an object of the present invention is to provide a monitoring determination device and a monitoring determination method that can suitably determine whether or not to monitor an obstacle according to the behavior of the host vehicle and the obstacle. Is to provide.

  The monitoring determination apparatus according to the present invention monitors the object based on an estimated collision time, which is an estimated time until the vehicle collides with the object, and a lateral shift amount of the object with respect to the traveling direction of the vehicle. Whether or not the object is not monitored when the lateral displacement amount is larger than a predetermined threshold value. When the deviation amount is smaller than a predetermined threshold value and the predicted collision time is smaller than the predetermined threshold value, it is determined that the object is monitored, and the lateral deviation amount is determined to be a predetermined threshold value. If it is smaller and the predicted collision time is larger than a predetermined threshold, it is determined whether or not the predicted collision time has changed from a state smaller than the predetermined threshold to a state larger than the threshold. If done, said change Performs determination of monitoring the object, and if not, it is determined not to monitor the object.

  The monitoring determination method of the present invention monitors the object based on an estimated collision time that is an estimated time until the vehicle collides with the object, and a lateral shift amount of the object with respect to the traveling direction of the vehicle. Whether or not the object is not monitored when the lateral displacement amount is larger than a predetermined threshold value. When the deviation amount is smaller than a predetermined threshold value and the predicted collision time is smaller than the predetermined threshold value, it is determined that the object is monitored, and the lateral deviation amount is determined to be a predetermined threshold value. If it is smaller and the predicted collision time is larger than a predetermined threshold, it is determined whether or not the predicted collision time has changed from a state smaller than the predetermined threshold to a state larger than the threshold. Done and said changed place Performs determination of monitoring the object, otherwise it is determined not to monitor the object.

  According to the present disclosure, it is possible to suitably determine whether or not to monitor an obstacle according to the behavior of the host vehicle and the obstacle.

The figure which shows an example of a structure of the vehicle containing the monitoring determination apparatus. The figure which shows an example of a structure of a monitoring judgment apparatus Diagram for explaining the concept of monitoring judgment processing Flow chart for explaining an operation example of the monitoring determination unit

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, the configuration of the vehicle 1 including the monitoring determination device 100 according to the embodiment of the present invention will be described.

  FIG. 1 is a diagram illustrating an example of a configuration of a vehicle 1 including a monitoring determination device 100.

  The vehicle 1 is a large vehicle such as a truck or a bus. As shown in FIG. 1, the vehicle 1 includes a radar device 11, a camera unit 12, a vehicle speed detection unit 13, a brake operation unit 14, a main brake 15, wheels 16, an auxiliary brake 17, an engine 18, an axle 19, and a monitoring determination device 100. Have

  The radar apparatus 11 receives the radar reflected wave that is returned by the transmitted radar transmission wave being reflected by an object existing around the vehicle 1. The radar apparatus 11 detects the distance and relative speed with respect to the object that is a radar reflector based on the phase difference and time difference between the transmitted radar transmission wave and the received radar reflected wave, and monitors and determines the detection result. Output to the device 100.

  In the present embodiment, the radar apparatus 11 mainly detects an object that exists in front of the vehicle 1. The object existing in front of the vehicle 1 includes, for example, a preceding vehicle, other obstacles, a roadside object when the road on which the vehicle 1 is traveling, and the like. In the present embodiment, these objects are collectively referred to as an obstacle.

  The camera unit 12 captures an image around the vehicle 1 and performs image analysis on the image, thereby detecting the distance and relative speed with an obstacle existing around the vehicle 1 and monitoring the detection result. Output to 100. In the present embodiment, the camera unit 12 mainly captures an image in front of the vehicle 1 as with the radar device 11. By these radar device 11 and camera unit 12, an obstacle that is present particularly in front of vehicle 1 is preferably detected.

  The vehicle speed detector 13 detects the vehicle speed of the vehicle 1. Specifically, the vehicle speed detection unit 13 is attached to, for example, an axle 19 described later, generates information related to the vehicle speed according to the rotation speed of the axle 19, and outputs the generated information to the monitoring determination device 100.

  The brake operation unit 14 is provided in the driver's seat of the vehicle 1 and receives an operation on the main brake 15. The main brake 15 generates a braking force for the wheels 16 in response to an operation on the brake operation unit 14. The brake operation unit 14 is a brake pedal, for example, and the main brake 15 is a so-called foot brake. That is, when the driver depresses the brake pedal, which is the brake operation unit 14, the main brake 15 generates a braking force against the wheels 16 in response to this, and as a result, the vehicle 1 decelerates.

  The auxiliary brake 17 is a means for braking the vehicle 1 as an auxiliary to the main brake 15 such as an exhaust brake or a retarder. The exhaust brake is provided with a valve that closes the exhaust pipe to increase the exhaust resistance and increase the rotational resistance of the engine 18 to enhance the action of the engine brake. The retarder applies a resistance force due to magnetic force, liquid, or the like to the axle 19 to suppress the rotation of the axle 19. The axle 19 is an axis to which the wheels 16 are attached.

  When there is an obstacle ahead of the vehicle 1 based on the detection results output from the radar device 11 and the camera unit 12, the monitoring determination apparatus 100 sets the obstacle as a target (target), and the obstacle Determine whether to track and monitor the object.

  Moreover, the monitoring determination apparatus 100 determines whether or not the vehicle 1 may collide with an obstacle being monitored (collision determination). In this collision determination, when it is determined that the vehicle 1 may collide with an obstacle, the monitoring determination device 100 determines whether the vehicle 1 and the obstacle are in accordance with the driver's operation according to the distance or relative speed between the vehicle 1 and the obstacle. First, an instruction for executing control necessary for avoiding the collision or reducing the impact at the time of the collision is output. Hereinafter, the control necessary for avoiding the collision or reducing the impact at the time of the collision is referred to as collision damage reduction control.

  The collision damage reduction control includes, for example, the following control. That is, for example, an alarm unit (not shown) issues a warning to the driver to call attention, or the main brake 15 and / or the auxiliary brake 17 is automatically actuated to reduce the speed of the vehicle. This control reduces damage or avoids the collision itself.

  Below, the structure and operation | movement of the monitoring determination apparatus 100 are demonstrated in detail.

  FIG. 2 is a diagram illustrating an example of the configuration of the monitoring determination device 100. As shown in FIG. 2, the monitoring determination device 100 includes a TTC calculation unit 101, a monitoring determination unit 102, and an automatic brake control unit 103.

  Based on the detection results output from the radar device 11 and the camera unit 12 and the vehicle speed of the vehicle 1 output from the vehicle speed detection unit 13, the TTC calculation unit 101 has a collision margin time (TTC: Time To Collision) [seconds]. Is calculated. The TTC is an index for predicting the time until the vehicle 1 collides with an obstacle when it is assumed that the current relative speed is maintained. The distance between the vehicle 1 and the obstacle is the distance of the obstacle to the vehicle 1. Calculated by dividing by relative speed. In the present embodiment, the vehicle speed of the vehicle 1 is larger than the speed of the obstacle, and the vehicle 1 collides with the obstacle when there is no change in the speed of the vehicle 1 and the obstacle.

  Based on the detection results output from the radar device 11 and the camera unit 12, the monitoring determination unit 102 sets the obstacle as a target and monitors whether the obstacle exists in front of the vehicle 1. (Monitoring judgment). In the present invention, monitoring means continuously collecting the position and moving speed of an obstacle (an object existing in front of the vehicle) and the distance and relative speed between the vehicle 1 and the obstacle. Details of the monitoring determination process for determining whether or not the monitoring determination unit 102 sets an obstacle as a target will be described later.

  When the TTC calculated by the TTC calculation unit 101 becomes smaller than a predetermined value, the automatic brake control unit 103 gives an instruction to execute automatic braking with the braking force according to the magnitude of the TTC value and the auxiliary brake 15 Output to the brake 17. In addition, an automatic brake means operating a brake automatically irrespective of a driver | operator's operation.

  Here, although the automatic brake control unit 103 determines the braking force of the automatic brake according to the value of TTC, the present invention is not limited to this. For example, the automatic brake control unit 103 may simply determine the braking force of the automatic brake according to the distance between the vehicle 1 and the obstacle, or simply determine the vehicle speed of the vehicle 1 or the relative speed of the obstacle with respect to the vehicle 1. The braking force may be determined accordingly.

  In the above, each structure which the vehicle 1 has was demonstrated. Below, the detail of the monitoring determination process which the monitoring determination part 102 performs is demonstrated.

  First, the monitoring determination unit 102 detects the amount of deviation of the obstacle from the vehicle 1 in the lateral direction based on the detection result acquired from the radar device 11 or the camera unit 12. In the present embodiment, this shift amount is referred to as a lateral position offset.

  The lateral position offset is, for example, an amount by which an obstacle that is a target candidate is deviated from the center of the image in an image in which the camera unit 12 captures the front direction of the vehicle 1. That is, the lateral position offset is a lateral displacement amount of the obstacle with respect to the traveling direction of the vehicle 1. Alternatively, a value obtained by correcting the shift amount in the image using the distance between the vehicle 1 and the obstacle acquired from the radar device 11 may be used as the lateral position offset. Further, when it is detected by analyzing the image captured by the camera unit 12 that the road on which the vehicle 1 is traveling is curved, the monitoring determination unit 102 determines the curvature of the road based on the image. By calculating the radius and subtracting the amount of bending of the road from the amount of deviation of the obstacle, the influence of the bending of the road on the lateral position offset may be corrected.

  Next, the monitoring determination unit 102 performs monitoring determination processing based on the value of the lateral position offset and the value of TTC at every predetermined time. FIG. 3 is a diagram for explaining the concept of the monitoring determination process.

  In FIG. 3, the horizontal axis is the horizontal position offset [m], and the vertical axis is TTC [seconds]. Hereinafter, the points plotted at the positions corresponding to the lateral position offset and TTC at each time point are referred to as plot points.

FIG. 3A shows an example in which a coordinate plane based on the lateral position offset and TTC is divided into regions A to C by a predetermined threshold value x _th and a predetermined threshold value t _th . The monitoring determination unit 102 determines whether or not to monitor an obstacle depending on in which region the plot point at that point in FIG. 3A exists.

At that point, smaller lateral position offset from the threshold x _th, when TTC is t _th smaller, that is, when the plot point is within the region A shown in FIG. 3A, the monitoring determination unit 102, when monitoring an obstacle Judgment is made. In addition, the case where the plot point exists in the area A illustrated in FIG. 3A is a case where the vehicle 1 may collide with an obstacle (high).

On the other hand, at that time, when the lateral position offset is greater than the threshold x _th, that is, when the plot point is within the area B shown in FIG. 3A, the monitoring determination unit 102, it is determined not to monitor the obstacle . This is because there is no possibility of collision with the obstacle (low) even if the vehicle 1 continues straight ahead at the current speed because the amount of lateral displacement is large.

At that time, when the lateral position offset is smaller than the threshold value x _th and TTC is larger than t _th , that is, when the plot point is in the region C shown in FIG. when changing from threshold t _th value smaller than the threshold t _th value greater than, i.e. only when the plot point has shifted from the region a to the region C, the same monitor as the previous determination result monitoring determination of the obstacle It is determined that it is, and otherwise it is determined that monitoring is not performed.

  Hereinafter, specific examples will be given with reference to FIGS. 3B and 3C. 3B and 3C are diagrams illustrating an example of transition between the regions illustrated in FIG. 3A. In FIG. 3B, the arrow P1 indicates that the plot point has shifted from the region A to the region C over time.

  As described above, when the plot point at that time is within the area A, the monitoring determination unit 102 determines that the obstacle is set as a target and monitored. This is because the vehicle 1 may collide with an obstacle in the region A in which the amount of lateral displacement is small and the margin time until the collision is short.

Here, as described above, when the TTC value becomes smaller than a predetermined value smaller than the predetermined threshold value t _th , the automatic brake control unit 103 executes automatic braking with a braking force corresponding to the magnitude of the TTC value. Is output to the main brake 15 and the auxiliary brake 17. Thereby, when the main brake 15 and / or the auxiliary brake 17 execute the automatic braking, the vehicle speed of the vehicle 1 is reduced.

  When the vehicle speed decreases, the distance between the vehicle 1 and the obstacle increases, and TTC may increase. In this case, due to the effect of automatic braking, TTC increases as indicated by an arrow P1 in FIG. 3B, and the plot point shifts from the region A to the region C.

  As described above, when the plot point shifts from the region A to the region C due to the change in TTC, the monitoring determination unit 102 monitors the obstacle (same as the previous determination result) as described above (continues monitoring). Judgment is made.

  On the other hand, as indicated by an arrow P2 in FIG. 3C, the plot point may shift from the region B to the region C as time passes. When the plot point is in the region B, as described above, the monitoring determination unit 102 determines that the obstacle is not monitored without setting the obstacle as the target. This is because it can be determined that there is no possibility of a collision with the vehicle 1 because the amount of lateral displacement is large. When the plot point moves from the region B to the region C, the monitoring determination unit 102 is the same as the previous determination result as described above, so the monitoring determination unit 102 does not set the obstacle as the target, It is determined that this obstacle is not monitored.

  As described above, the monitoring determination unit 102 monitors the obstacle when the plot point is within the region C and when the plot point shifts from the region A to the region C due to a change in TTC over time. Judgment is made. On the other hand, when the plot point is in the region C and the plot point shifts from the region B to the region C over time, the monitoring determination unit 102 determines that the obstacle is not monitored. . In addition, although illustration is omitted, when the plot point is in the region C at the time of the first determination, the monitoring determination unit 102 determines that the obstacle is not monitored as in the case of shifting from the region B to the region C. I do.

  The reason why the monitoring determination unit 102 determines that the obstacle is monitored when the plot point shifts from the region A to the region C due to a change in TTC with the passage of time is, for example, as follows. The case where the plot point shifts from the region A to the region C is a case where the obstacle set as the target object has deviated from the monitoring condition due to a change in TTC. However, when the vehicle 1 is accelerated by the driver's operation or the obstacle is decelerated, there is a possibility that the TTC becomes small again and the plot point returns to the region A. Considering such a case, it is preferable to continuously monitor the obstacle.

  On the other hand, when the plot point shifts from the region B to the region C, when the lateral position offset of the obstacle that is not originally set as the target is reduced, that is, for example, the vehicle ahead in another lane changes the lane. For example, a case where the vehicle has moved forward in the same lane as the vehicle 1 is assumed. In such a case, since the TTC between the vehicle 1 and the obstacle is originally not small and the possibility of a collision is low, the necessity to newly set the obstacle as a target is low at that time. Conceivable. Therefore, in such a case, the monitoring determination unit 102 determines that the obstacle is not monitored without setting the obstacle as the target. If the plot point is within the region C at the time of the first determination, it is determined that the obstacle is not monitored because the condition for monitoring the obstacle is not satisfied.

  By performing the monitoring determination in this way, it is possible to monitor the obstacle according to the behavior of the vehicle 1 and the obstacle (target object).

Next, an operation example of the monitoring determination unit 102 will be described. FIG. 4 is a flowchart for explaining an operation example of the monitoring determination unit 102. Monitoring determination unit 102, based on the detection result acquired from the radar device 11 or the camera unit 12 detects the value of the horizontal position offset at a certain point in time, whether the value is a predetermined threshold value x _th smaller Determine (step S1).

If the value of the horizontal position offset is determined to be smaller than the predetermined threshold value x _th at step S1, then the monitoring determination unit 102, the value of TTC obtained from TTC calculating section 101 reaches a predetermined threshold value t _It is determined whether it is smaller than _th (step S2).

If it is not determined in step S2 that the value of TTC is smaller than the predetermined threshold value t _th , the monitoring determination unit 102 changes the TTC so that plot points are changed from region A to region C in FIG. It is determined whether or not the transition has been made (step S3). If it is determined in step S3 that the plot point has shifted from the region A to the region C in FIG. 3, the flow proceeds to step S4 described later, and otherwise proceeds to step S5 described later.

On the other hand, if it is determined in step S2 that the value of TTC is smaller than the predetermined threshold value t _th and if it is determined in step S3 that the plot point has shifted from region A to region C, the monitoring determination unit 102 determines that the obstacle is monitored (step S4).

Further, in step S1, when the value of the horizontal position offset is not determined that the predetermined threshold value x _th smaller and, when the plot point to the region C from the region A in Step S3 is not determined to have migrated The monitoring determination unit 102 determines that the obstacle is not monitored (step S5).

  And if the monitoring determination part 102 performs monitoring determination in step S3 and step S5, a flow will return to step S1. In this way, the monitoring determination unit 102 repeats the monitoring determination as shown in FIG. 3 every predetermined time.

  As described above, the monitoring / determining device according to the embodiment of the present invention is based on the estimated collision time (TTC), which is the estimated time until the vehicle 1 collides with an obstacle, and the obstacle in the traveling direction of the vehicle 1. Based on the amount of lateral displacement (lateral position offset), the monitoring determination unit 102 repeats the determination as to whether or not to monitor an obstacle every predetermined time. If it is larger than the predetermined threshold value (in the case of region B shown in FIG. 3), it is determined that the obstacle is not monitored, the lateral position offset is smaller than the predetermined threshold value, and TTC is a predetermined threshold value. If smaller than the value (in the case of the area A shown in FIG. 3), it is determined that the obstacle is monitored, and the lateral position offset is smaller than the predetermined threshold value and the TTC is larger than the predetermined threshold value. (Region shown in FIG. In the case of (1), it is determined whether or not the estimated collision time has changed from a state smaller than a predetermined threshold value to a state larger than the threshold value. If not, it is determined that the obstacle is not monitored.

  With such a configuration, when the lateral position offset is smaller than the predetermined threshold value and TTC is larger than the predetermined threshold value, that is, when the plot point is in the region C in FIG. Thus, only when the region A has shifted to the region C, the monitoring determination unit 102 determines that the obstacle is to be monitored, and otherwise determines that the obstacle is not to be monitored. By performing the monitoring determination in this way, it is possible to monitor the obstacle according to the behavior of the vehicle 1 and the obstacle (target object).

  The above-described embodiments are merely examples of implementation in carrying out the present invention, and the technical scope of the present invention is not limited by these embodiments. That is, the present invention can be implemented in various forms without departing from the gist or the main features thereof.

  The above-described monitoring determination apparatus 100 performs the above-described operation by executing a data recording program stored in a storage medium such as a magnetic disk, an optical disk, or a flash memory (not shown) on an arithmetic device such as a CPU (not shown). Do. Alternatively, the monitoring determination device 100 may be realized using a hardware circuit. Further, the data recording program executed in the monitoring determination device 100 may be provided via a public communication network such as the Internet, in addition to being provided by being stored in a storage medium.

  INDUSTRIAL APPLICABILITY The present invention is useful for a monitoring / determination device that detects and monitors an object present around a host vehicle.

DESCRIPTION OF SYMBOLS 100 Monitoring judgment apparatus 101 TTC calculation part 102 Monitoring judgment part 103 Automatic brake control part 1 Vehicle 11 Radar apparatus 12 Camera part 13 Vehicle speed detection part 14 Brake operation part 15 Main brake 16 Wheel 17 Auxiliary brake 18 Engine 19 Axle

Claims (3)

It is determined for a predetermined time whether or not the object is to be monitored based on the estimated collision time that is the estimated time until the vehicle collides with the object and the amount of lateral displacement of the object with respect to the traveling direction of the vehicle. A monitoring determination unit that repeats every time,
If the lateral displacement amount is larger than a predetermined threshold value, it is determined that the object is not monitored, the lateral displacement amount is smaller than the predetermined threshold value, and the expected collision time is predetermined. If the threshold value is smaller than the threshold value, it is determined that the object is to be monitored, and the lateral displacement amount is smaller than a predetermined threshold value and the predicted collision time is larger than the predetermined threshold value. Determines whether or not the estimated collision time has changed from a state smaller than a predetermined threshold to a state larger than the threshold, and determines that the object is to be monitored if the change has occurred, Otherwise, it is determined that the object is not monitored.
Monitoring judgment device. An automatic brake control unit that automatically activates the brake based on the estimated collision time;
The determination performed by the monitoring determination unit is a determination as to whether or not the object is to be monitored as an object for avoiding a collision or reducing the damage of the collision by an automatic brake performed by the automatic brake control unit.
The monitoring determination apparatus according to claim 1. It is determined for a predetermined time whether or not the object is to be monitored based on the estimated collision time that is the estimated time until the vehicle collides with the object and the amount of lateral displacement of the object with respect to the traveling direction of the vehicle. A monitoring judgment method that repeats every time,
If the lateral displacement amount is larger than a predetermined threshold value, it is determined that the object is not monitored, the lateral displacement amount is smaller than the predetermined threshold value, and the expected collision time is predetermined. If the threshold value is smaller than the threshold value, it is determined that the object is to be monitored, and the lateral displacement amount is smaller than a predetermined threshold value and the predicted collision time is larger than the predetermined threshold value. Determines whether or not the estimated collision time has changed from a state smaller than a predetermined threshold to a state larger than the threshold, and determines that the object is to be monitored if the change has occurred, Otherwise, it is determined that the object is not monitored.
Monitoring judgment method.

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