JP5321153B2 - Driving operation support device and driving operation support method - Google Patents

Description

  The present invention relates to a driving operation support device and a driving operation support method that support a vehicle operation performed by a driver to avoid contact with an obstacle.

  Conventionally, an obstacle existing ahead of the traveling path of the host vehicle is detected, and a steering pattern (time-series change in steering angle) for avoiding contact with the detected obstacle is calculated, and the calculated steering is calculated. There is known a driving operation support device that supports the driver's avoidance operation for an obstacle by controlling the steering of the host vehicle so as to follow the pattern.

Japanese Patent No. 3130970

  According to the conventional driving operation support device, when the avoidance control intervenes, the target steering angle is delayed with respect to the driver's steering angle, in other words, the driver starts the avoidance operation before the avoidance control intervenes. In this case, the steering control in the direction opposite to the steering angle direction of the driver may be activated, and the driver may feel uncomfortable with the avoidance control.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a driving operation support apparatus and a driving operation support method that can reduce the uncomfortable feeling felt by the driver with respect to avoidance control.

The driving operation support device and the driving operation support method according to the present invention predict the steering amount of the host vehicle at the time of starting the steering control based on the steering amount of the host vehicle, and perform steering for increasing the predicted steering amount. Calculate the correction amount, correct the predicted steering amount using the calculated steering correction amount, calculate the time when the target steering amount of the avoidance steering pattern becomes the corrected steering amount, and avoid from the calculated time Steering control is performed to avoid the vehicle from coming into contact with an obstacle according to the steering pattern.

According to the driving operation support device and the driving operation support method according to the present invention, when the avoidance control is started, the target steering amount is corrected by the steering correction amount for increasing the driver's steering amount. The uncomfortable feeling felt by the driver can be reduced.

It is a block diagram which shows the structure of the driving operation assistance apparatus used as embodiment of this invention. It is a functional block diagram of the driving operation support device shown in FIG. It is a flowchart figure which shows the flow of the driving operation assistance process used as embodiment of this invention. It is a figure which shows an example of (a) basic steering pattern and (b) avoidance locus | trajectory. It is a figure which shows the modification of a basic steering pattern. FIG. 4 shows results of experimentally measuring the response of the steering angle and the steering angle command value when the driving operation support process shown in FIG. 3 is not performed at the time of switching from the steering operation by the driver to the autonomous steering control. FIG. 4 shows the results of experimentally measuring the response of the steering angle and the steering angle command value when the driving operation support process shown in FIG. 3 is performed at the time of switching from the steering operation by the driver to the autonomous steering control. The result of having measured the torque reaction force by experiment when not performing the driving operation assistance process shown in FIG. 3 at the time of switching from the steering operation by the driver to the autonomous steering control is shown. FIG. 4 shows a result of experimentally measuring a torque reaction force when the driving operation support process shown in FIG. 3 is performed at the time of switching from the steering operation by the driver to the autonomous steering control.

  Hereinafter, with reference to the drawings, a driving operation support device and its operation (driving operation support method) according to an embodiment of the present invention will be described.

[Configuration of driving support device]
First, with reference to FIG. 1, FIG. 2, the structure of the driving operation assistance apparatus used as embodiment of this invention is demonstrated.

  As shown in FIG. 1, the driving operation support apparatus according to the embodiment of the present invention is mounted on a vehicle 1 having a power steering unit, and includes a laser radar 2, a laser radar control unit 3, a photographing apparatus 4, an image processing apparatus 5, and the like. A yaw rate sensor 6, a lateral G / front / rear G sensor 7, wheel speed sensors 8a to 8d, a vehicle speed sensor 9, a steering angle sensor 10, a torque sensor 11, a power steering control unit 12, and a control unit 13 are provided as main components.

  The laser radar 2 irradiates laser light in front of the vehicle 1 and receives reflected light from an object irradiated with the laser light by a light receiving system. The laser radar control unit 3 measures the presence / absence of an obstacle, the relative distance and relative speed of the obstacle with respect to the vehicle 1 by detecting a time difference between the laser emission time and the reflected light reception time. The laser radar control unit 3 inputs the measurement result to the control unit 13. The imaging device 4 is provided in the front part of the vehicle 1, captures an image in front of the vehicle 1, and outputs it to the image processing device 5. The image processing device 5 detects the external environment information of the vehicle such as the surrounding vehicle and the road environment by performing image processing on the photographed image of the photographing device 4, and inputs the detection result to the control unit 13. The laser radar 2, the laser radar control unit 3, the imaging device 4, and the image processing device 5 function as the external environment detection means 21 according to the present invention shown in FIG.

  The yaw rate sensor 6 detects the yaw rate generated in the vehicle 1 and inputs the detected value to the control unit 13. The lateral G / longitudinal G sensor 7 detects lateral acceleration G (lateral G) and longitudinal acceleration G (longitudinal G) generated in the vehicle 1, and inputs the detected values to the control unit 13. The wheel speed sensors 8 a to 8 d and the vehicle speed sensor 9 detect the traveling speed of the vehicle 1 and input the detected value to the control unit 13. The steering angle sensor 10 detects the steering angle and the steering angular velocity of the steering wheel 14 of the vehicle 1 and inputs the detected value to the control unit 13. The torque sensor 11 detects torque generated by steering the steering wheel 14 and inputs the detected value to the control unit 13. When the detection values of these sensors have right and left directions, the detection values in the right direction are positive, and when there are front and rear directions, the detection values in the front direction are positive. That is, the yaw angle is positive when turning right, and the lateral displacement is positive when it is shifted to the right with respect to the obstacle. The traveling direction of the vehicle 1 is also positive. The yaw rate sensor 6, the lateral G / front / rear G sensor 7, the wheel speed sensors 8a to 8d, the vehicle speed sensor 9, the steering angle sensor 10, and the torque sensor 11 function as the own vehicle state detection means 22 according to the present invention shown in FIG. To do.

  The power steering control unit 12 controls the steering operation of the vehicle 1 by operating the steering rack 16 left and right by controlling the power steering unit 15 according to the control unit 13 or a command value from the outside. The power steering control unit 12 functions as the avoidance control means 28 according to the present invention shown in FIG. The control unit 13 is constituted by a microcomputer, and includes a laser radar control unit 3, an image processing device 5, a yaw rate sensor 6, a lateral G / front / rear G sensor 7, wheel speed sensors 8a to 8d, a vehicle speed sensor 9, a steering angle sensor 10, The operation of the power steering control unit 12 is controlled based on the information input from the torque sensor 11. The control unit 13 executes the control program by the internal CPU, whereby the emergency level calculation means 23, the avoidance control start determination means 24, the avoidance steering pattern calculation means 25, and the steering operation state prediction means according to the present invention shown in FIG. 26 and steering correction amount calculating means 27. The power steering control unit 12 and the control unit 13 function as avoidance control means 28 according to the present invention shown in FIG.

[Driving operation support processing]
In the driving operation support device having such a configuration, the control unit 13 executes the driving operation support process described below, thereby reducing the uncomfortable feeling that the driver feels with respect to the avoidance control. Hereinafter, the operation of the control unit 13 when executing the driving operation support process will be described with reference to the flowchart shown in FIG.

  The flowchart shown in FIG. 3 starts at the timing when the ignition switch of the vehicle 1 is switched from the off state to the on state, and the driving operation support process proceeds to step S1.

  In the process of step S1, the control unit 13 uses the input information from the laser radar control unit 3 and the image processing device 5 to obstruct the vehicle 1 in an area where the vehicle 1 can travel (hereinafter referred to as “traveling road”). Is detected. Since the obstacle detection method is already known at the time of filing of the present invention, a detailed description thereof will be omitted. For details of the obstacle detection method, refer to, for example, Japanese Patent Application Laid-Open No. 2000-207693. The control unit 13 then detects the obstacle based on the position information of the obstacle, the external environment information of the vehicle 1 detected by the image processing device 5, and the vehicle speed detected by the wheel speed sensors 8 a to 8 d and the vehicle speed sensor 9. The urgency level of the vehicle 1 for avoiding the contact is calculated.

Specifically, the control unit 13 calculates a time TTC until the vehicle 1 comes into contact with an obstacle using the following formula 1, and when the calculated time TTC is equal to or greater than a predetermined value T1, Is determined to be a “safe” level. On the other hand, if the calculated time TTC is greater than or equal to the predetermined value T2 (<predetermined value T1) and less than the predetermined value T1, the control unit 13 determines the urgency level to be the “warning” level, and the calculated time TTC is equal to the predetermined value T2. If it is less, the control unit 13 determines the urgency level to be a “danger” level. In Equation 1, parameters Y ₀ , Vc, and V _y0 indicate the relative longitudinal distance of the obstacle with respect to the vehicle 1, the longitudinal speed of the vehicle 1, and the longitudinal speed of the obstacle, respectively. Thereby, the process of step S1 is completed and the driving operation support process proceeds to the process of step 2.

  In the process of step S2, the control unit 13 determines which of the “safety”, “warning”, and “danger” levels is the urgency calculated by the process of step S1. If the urgency level is the “safe” level, the control unit 13 returns the driving operation support process to the process of step 1. On the other hand, if the urgency level is “warning level”, the control unit 13 advances the driving operation support process to step S3. If the urgency level is “risk level”, the control unit 13 sets the driving operation support process. The process proceeds to step S4.

  In the process of step S3, the control unit 13 outputs a warning that the vehicle 1 may come into contact with an obstacle, and then the driver avoids contact with the obstacle via the steering angle sensor 10. It is determined whether or not the steering wheel 14 has been steered by a predetermined threshold (a predetermined steering angle or a predetermined steering angular velocity) within a predetermined time. As a result of the determination, if the driver does not steer the steering wheel 14 beyond a predetermined threshold, the control unit 13 returns the driving operation support process to the process of step S1. On the other hand, when the driver steers the steering wheel 14 by a predetermined threshold or more, the control unit 13 advances the driving operation support process to the process of step S4.

In the processing of step S4, the control unit 13 uses the input information from the laser radar control unit 3 and the image processing device 5 to avoid the target left-right movement distance X ₀ of the vehicle 1 to avoid contact with an obstacle. (Distance between the obstacle and the vehicle 1 when the obstacle position is reached) is calculated. The control unit 13 calculates a steering pattern that can move to the target lateral movement distance X ₀ using the vehicle model based on the calculated target lateral movement distance X ₀ and the traveling state (vehicle speed, yaw rate) of the vehicle 1. To do. Specifically, the control unit 13 stores in advance a sine wave-like steering pattern having a cycle Ts and an amplitude θmax as shown in FIG. 4A as a basic steering pattern, and changes the values of the cycle Ts and the amplitude θmax. Thus, a time-series change of the steering angle that avoids contact with the obstacle at a position that is a distance X _{0 in the} lateral direction from the obstacle as shown in FIG. 4B is calculated as a steering pattern. However, the present invention is not limited to this embodiment, and the control unit 13 stores in advance, for example, a steering pattern having a waveform other than a sine wave as shown in FIGS. 5A and 5B as a basic steering pattern. The avoidance steering pattern may be calculated by changing the parameters of these basic steering patterns. Thereby, the process of step S4 is completed and the driving operation support process proceeds to the process of step S5.

In the process of step S5, the control unit 13 detects the steering angle theta _a steering angular speed omega _a of the steering wheel 14 through a steering angle sensor 10, by the driver by Equation 2 below using the detection value The steering angle θ _next and the steering angular velocity ω _next at the time of switching from the steering operation to the autonomous steering control are predicted. In Equations 2 and 3, the parameter δT indicates the time required for switching from the steering operation to the autonomous steering control. Further, the control unit 13 may predict the steering angle θ _next and the steering angular velocity ω _next when switching from the steering operation by the driver to the autonomous steering control using the yaw angle or the yaw rate. Thereby, the process of step S5 is completed and the driving operation support process proceeds to the process of step S6.

In the process of step S6, when the control unit 13 switches from the steering operation to the autonomous steering control based on the steering angle θnext and the steering angular speed ωnext predicted by the process of step S5 , the target steering angle and the target angular speed are changed to the steering angle. as not delayed with respect to the steering angular velocity Omeganext and Shitanext, calculates the steering angle correction amount for increasing the steering angle Shitanext, and steering angular velocity Omeganext. Specifically, the control unit 13 calculates the steering angle correction amount θp according to the following formula 4, and increases the steering angle correction amount as the steering angular velocity ωnext increases. Further, the control unit 13 may decrease the value of the steering angle correction amount as the steering angle θnext is closer to the maximum steering angle command value. The control unit 13 may increase the value of the steering angle correction amount as the time TTC calculated by the process of step S1 is shorter. In Equation 4, the parameter Ka indicates a constant (> 0). Thereby, the process of step S6 is completed and a driving operation assistance process progresses to the process of step S7.

In the process at step S7, the control unit 13, a value obtained by adding the steering angle correction amount θp calculated by the process at step S6 the predicted steering angle θnext by the processing in step S5, the autonomous steering from the steering operation by the driver calculated by the target steering angle at the time of switching to the operation, to calculate the time on the avoidance steering pattern as a target steering angle calculated. Thereby, the process of step S7 is completed and the driving operation support process proceeds to the process of step S8.

In the process of step S8, the control unit 13 controls the power steering control unit 12 to execute the steering control according to the avoidance steering pattern from the time calculated by the process of step S7. Specifically, the control unit 13 calculates the deviation θ _r between the actual steering angle and the target steering angle, and uses the calculated deviation θ _r to set the command value θ _v calculated by the following formula 5 as the target steering. The angle command value is output to the power steering control unit 12. In Equation 5, the parameters K _p , K _d , and _Ki indicate constants (> 0). When the calculated target steering angle command value θ _v is equal to or larger than the maximum steering angle command value θ ₀ that can be output to the steering control unit 12, the control unit 13 uses the maximum steering angle command value θ ₀ as the target steering angle command value. Output. Then, the power steering control unit 12 controls the steering operation of the vehicle by controlling the power steering unit 15 according to the target steering angle command value θ _v from the control unit 13 to operate the steering rack 16 left and right (autonomous steering control). ) Thereby, the process of step S8 is completed and the driving operation support process proceeds to the process of step S9.

In the process of step S9, the control unit 13 determines that the absolute value of the deviation θ _r between the actual steering angle and the target steering angle is less than a predetermined value, the absolute value of the speed of the vehicle 1 is less than a predetermined value, and It is determined whether or not the absolute value of the relative distance to the obstacle is greater than or equal to a predetermined value. The absolute value of the deviation θ _r between the actual steering angle and the target steering angle is less than the predetermined value, the absolute value of the speed of the vehicle 1 is less than the predetermined value, and the absolute relative distance between the vehicle 1 and the obstacle is If the value is not greater than or equal to the predetermined value, the control unit 13 returns the driving operation support process to the process of step S8. On the other hand, the absolute value of the deviation θ _r between the actual steering angle and the target steering angle is less than the predetermined value, the absolute value of the speed of the vehicle 1 is less than the predetermined value, and the relative distance between the vehicle 1 and the obstacle is If the absolute value is greater than or equal to the predetermined value, the control unit 13 ends the series of driving operation support processing.

[Example]
FIG. 6 and FIG. 6 show the results of experimentally measuring the response of the steering angle and the steering angle command value when the driving operation support processing is not performed and when the driving operation support processing is performed when switching from the steering operation by the driver to the autonomous steering control. 7 shows. When the driving operation support processing is not performed at the time of switching from the steering operation by the driver to the autonomous steering control, as shown in the regions R1 and R2 in FIGS. It operates in the opposite direction to the steering direction of the person. For this reason, the driver may feel uncomfortable with the autonomous steering control because the steering direction by the autonomous steering control is different from the steering direction of the driver. On the other hand, when the driving operation support process is performed at the time of switching from the steering operation by the driver to the autonomous steering control, as shown in regions R3 and R4 in FIGS. 7A and 7B, Since the reverse response of the steering angle can be almost eliminated, it is considered that the driver hardly feels the sense of incongruity with the autonomous steering control.

  FIG. 8 and FIG. 9 show the results of experimentally measuring the torque reaction force when the driving operation support processing is not performed and when the driving operation support processing is performed when switching from the steering operation by the driver to the autonomous steering control. 8 and 9, the solid line and the alternate long and short dash line indicate the torque reaction force and the autonomous steering locus, respectively. When the driving operation support process is not performed at the time of switching from the steering operation by the driver to the autonomous steering control, a large torque reaction force is generated in the direction opposite to the command value as shown in a region R5 in FIG. Yes. For this reason, the driver may feel uncomfortable with the autonomous steering control because the steering direction by the autonomous steering control is different from the steering direction of the driver. On the other hand, when the above-described driving operation support processing is performed at the time of switching from the steering operation by the driver to the autonomous steering control, as shown in a region R6 in FIG. Since the torque reaction force is generated, it is considered that the driver hardly feels uncomfortable with the autonomous steering control.

As is clear from the above description, according to the driving operation support processing according to the embodiment of the present invention, the control angle is set to the steering angle θnext when the control unit 13 switches from the steering operation to the autonomous steering control. calculated by the target steering angle at the time of switching to autonomous steering operation the added value from the steering operation by the driver, it calculates the time on the avoidance steering pattern as a target steering angle calculated. Then, the control unit 13 executes steering control for avoiding the host vehicle from contacting the obstacle according to the avoidance steering pattern from the calculated time. According to such a configuration, since the target steering angle is delayed with respect to the steering angle at the time of switching from the steering operation to the autonomous steering control, the autonomous steering control in the direction opposite to the steering direction of the driver does not operate. The uncomfortable feeling felt by the driver with respect to the avoidance control can be reduced.

Further, according to the driving operation support process according to the embodiment of the present invention, the control unit 13 increases the steering correction amount as the steering angular velocity ω _next at the time of switching from the steering operation to the autonomous steering control increases. Can perform the steering control in consideration of the risk felt for obstacle avoidance. Further, according to the driving operation support processing according to the embodiment of the present invention, the control unit 13 increases the steering correction amount as the steering angle θ _next at the time of switching from the steering operation to the autonomous steering control approaches the maximum steering angle command value. Therefore, it is possible to prevent the driver from feeling uncomfortable due to an increase in steering at the time of switching from the steering operation to the autonomous steering control. Further, according to the driving operation support process according to the embodiment of the present invention, the control unit 13 increases the steering correction amount as the time until the vehicle 1 comes into contact with the obstacle becomes shorter. Steering control can be performed in consideration of the risk of the relative positional relationship between the vehicle and the obstacle.

  Further, according to the driving operation support process according to the embodiment of the present invention, the control unit 13 calculates the emergency level of the vehicle 1 for avoiding contact with an obstacle, and the calculated emergency level is equal to or greater than a predetermined value. If there is, it is determined whether or not the steering angle or steering angular velocity of the vehicle 1 is greater than or equal to a predetermined value, and when the steering angle or steering angular velocity of the vehicle 1 is greater than or equal to a predetermined value, the processing of steps S4 to S9 is performed. Therefore, in a state where there is a risk that the vehicle 1 comes into contact with the obstacle, the steering control can be performed in consideration of the willingness to avoid the obstacle or the risk that the driver feels for avoiding the obstacle. .

  As mentioned above, although embodiment which applied the invention made by the present inventors was described, this invention is not limited by the description and drawing which make a part of indication of this invention by this embodiment. That is, it should be added that other embodiments, examples, operation techniques, and the like made by those skilled in the art based on the above embodiments are all included in the scope of the present invention.

1: vehicle 2: laser radar 3: laser radar control unit 4: imaging device 5: image processing device 6: yaw rate sensor 7: lateral G / front and rear G sensors 8a to 8d: wheel speed sensor 9: vehicle speed sensor 10: steering angle sensor 11: Torque sensor 12: Power steering control unit 13: Control unit 14: Steering wheel 15: Power steering unit 16: Steering rack 21: External environment detection means 22: Own vehicle state detection means 23: Emergency level calculation means 24: Avoidance control Start determination means 25: avoidance steering pattern calculation means 26: steering operation state prediction means 27: steering correction amount calculation means 28: avoidance control means

Claims (7)

An external environment detection means for detecting information related to the external environment of the host vehicle including obstacles existing around the host vehicle;
Own vehicle state detecting means for detecting the running state of the own vehicle;
Based on the travel path of the host vehicle detected by the external environment detection unit and the travel state of the host vehicle detected by the host vehicle state detection unit, the host vehicle contacts the obstacle detected by the external environment detection unit. Avoidance steering pattern calculation means for calculating a time series change of the target steering angle and the target steering angular velocity of the host vehicle for avoiding the operation as an avoidance steering pattern;
Steering operation state prediction means for predicting the steering angle and steering angular speed of the host vehicle at the time of starting steering control based on the steering angle and steering angular speed of the host vehicle detected by the host vehicle state detection means;
Steering correction amount calculating means for calculating a steering correction angle for increasing the steering angle as a numerical value proportional to the steering angular velocity with respect to the steering angle predicted by the steering operation state prediction means;
The steering correction amount calculated by using the steering correction angle calculated by means corrects the steering angle predicted by the steering operation state predicting means, a time when the steering angle target steering angle is corrected in the avoidance steering pattern the avoidance control means for executing the steering angle after the correction, and the calculated on the basis of the steering angular velocity, the steering control for avoiding the host vehicle contacts the obstacle in accordance with avoidance steering pattern from the calculated time ,
A driving operation support device comprising: The driving operation support device according to claim 1,
The steering correction amount calculating means increases the steering correction angle as the steering angular velocity predicted by the steering operation state prediction means increases. In the driving operation support device according to claim 1 or 2,
The steering correction amount calculating means reduces the steering correction angle as the steering angle predicted by the steering operation state prediction means approaches a maximum steering angle command value. In the driving operation support device according to any one of claims 1 to 3,
The driving operation support device, wherein the steering correction amount calculation means increases the steering correction angle as the time until the host vehicle comes into contact with the obstacle detected by the external environment detection means decreases. In the driving operation support device according to any one of claims 1 to 4,
Urgent level calculating means for calculating the urgent level of the host vehicle for avoiding contact with the obstacle detected by the external environment detecting means;
When the urgency level calculated by the urgency level calculation unit is equal to or greater than a predetermined value, it is determined whether or not the steering angle of the host vehicle detected by the host vehicle state detection unit is equal to or greater than a predetermined value. When the steering angle is greater than or equal to a predetermined value, the avoidance steering pattern calculation means, the steering operation state prediction means, the steering correction amount calculation means, and the avoidance control start determination means for starting the operation of the avoidance control means A driving operation support apparatus comprising: In the driving operation support device according to any one of claims 1 to 4,
Urgent level calculating means for calculating the urgent level of the host vehicle for avoiding contact with the obstacle detected by the external environment detecting means;
When the urgency level calculated by the urgency level calculation means is greater than or equal to a predetermined value, it is determined whether or not the steering angular velocity of the host vehicle detected by the host vehicle state detection means is greater than or equal to a predetermined value. When the steering angular velocity is greater than or equal to a predetermined value, the avoidance steering pattern calculation means, the steering operation state prediction means, the steering correction amount calculation means, and the avoidance control start determination means for starting the operation of the avoidance control means A driving operation support apparatus comprising: An external environment detection process in which the external environment detection means detects information related to the external environment of the host vehicle including obstacles existing around the host vehicle;
Vehicle state detection means, and the vehicle state detection processing for detecting the running condition of the vehicle,
Based on the traveling path of the host vehicle and the traveling state of the host vehicle, a time series change of the target steering angle and the target steering angular velocity of the host vehicle for avoiding contact of the host vehicle with an obstacle is calculated as an avoidance steering pattern. Processing,
A process of predicting the steering angle and the steering angular velocity of the host vehicle at the time of starting the steering control based on the steering angle and the steering angular velocity of the host vehicle;
A process of calculating a steering correction angle for increasing the steering angle as a numerical value proportional to the steering angular velocity with respect to the predicted steering angle ;
By using the calculated steering correction angle by correcting the predicted steering angle, the time at which the steering angle target steering angle is corrected in the avoidance steering pattern, the steering angle after the correction, and on the basis of the steering angular velocity A process of calculating and executing steering control for avoiding contact of the vehicle with the obstacle according to an avoidance steering pattern from the calculated time ;
A driving operation support method characterized by comprising:

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