JP2011145922A - Vehicle speed control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle speed control device capable of alerting a driver according to the driver's condition so that he will not depend too much on ACC control. <P>SOLUTION: The vehicle speed control device includes: a target information calculation means for calculating information about the movement of a moving body as target information by applying an electric wave to the moving body in front of a vehicle, and receiving a reflected wave reflected from the moving body; a face information calculation means for imaging the face of the driver of the vehicle, and calculating information about the driver's face using the image taken; a vehicle speed control means for controlling the vehicle speed of the vehicle based on the target information; an alert means for performing an alert action to the driver when the vehicle is stopped by the vehicle speed control means; and an alert changing means for changing according to the face information the mode of the alert action performed by the alert means. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vehicle speed control device, and more specifically to a vehicle speed control device that recognizes other vehicles ahead of the vehicle and controls the movement of the vehicle so as to maintain a predetermined distance.

  In recent years, a radar device mounted on the host vehicle recognizes the distance between the host vehicle and another vehicle traveling in front of the host vehicle, and keeps the distance between the host vehicle and the other vehicle constant (hereinafter referred to as ACC). Devices that can perform (sometimes referred to as (Active Cruise Control) control) have been put into practical use. As an example of such an apparatus, there is an apparatus disclosed in Patent Document 1, for example.

JP 2009-101822 A

  The device disclosed in Patent Document 1 stops the operation of the follow-up traveling control (corresponding to the ACC control) when the line-of-sight direction of the driver (driver) of the host vehicle is not the forward direction. In other words, from the state where the host vehicle and the other vehicle traveling in front of the host vehicle are stopped, the follow-up traveling control is stopped when the line-of-sight direction of the driver of the host vehicle is not the forward direction when the other vehicle starts. It is something to be made.

  Furthermore, the device disclosed in Patent Literature 1 is directed to the driver's line-of-sight direction when the other vehicle starts from a state where the own vehicle and the other vehicle traveling in front of the own vehicle are stopped. When is not in the forward direction, a warning that the other vehicle has started is issued to the driver of the host vehicle.

  By the way, the ACC control performs control to keep the distance between the host vehicle and the other vehicle constant. For example, when the other vehicle decelerates and the host vehicle and the other vehicle approach each other, the brake device of the host vehicle is used. Is controlled so that the host vehicle decelerates or stops. In general, when the brake device of the host vehicle is controlled and the host vehicle decelerates, an alarm or the like is urged so that the driver himself performs a brake operation so that the driver does not depend too much on the ACC control. In particular, while the host vehicle and another vehicle approach each other while the host vehicle is traveling, the driver depends on the control to decelerate the host vehicle by controlling the brake device of the host vehicle. It is considered that it is excessive dependence to depend on the control to stop the control or hold the stop state.

  However, when the host vehicle's brake device is controlled and the host vehicle decelerates or stops, the driver may feel troublesome if he / she is prompted to perform a brake operation. That is, for example, every time the other vehicle decelerates and the own vehicle approaches the other vehicle, an alarm or the like is issued so that the driver does not depend on the ACC control too much (so that the driver performs the brake operation). I felt annoying. Further, the apparatus disclosed in Patent Document 1 cannot reduce the annoyance of an alarm or the like that is performed each time the other vehicle decelerates and the own vehicle approaches the other vehicle.

  The present invention has been made in view of the above circumstances, and its purpose is to urge a driver to be alerted according to the state of the driver so as not to depend on ACC control too much. An object of the present invention is to provide a vehicle speed control device that can perform the above-described operation.

  In order to achieve the above object, the present invention employs the following configuration. That is, the first invention is a vehicle speed control device that recognizes a moving body in front of the vehicle and controls the vehicle speed of the vehicle so that the moving body and the vehicle maintain a predetermined distance. The vehicle speed control device irradiates a moving body in front of the vehicle with electromagnetic waves and receives reflected waves reflected from the moving body, thereby calculating information relating to the movement of the moving body as target information; Face information calculation means for capturing an image of the driver's face of the vehicle and calculating information related to the driver's face as face information using the captured image, and controlling the vehicle speed of the vehicle based on the target information Vehicle speed control means, warning means for performing a warning operation to the driver when the vehicle stops by the vehicle speed control means, and a mode of the warning operation performed by the warning means based on the face information And an alarm changing means.

  In a second aspect based on the first aspect, the face information calculation means calculates a face direction angle of the driver based on the imaging direction as the face information. The warning changing means changes a mode of the warning operation performed by the warning means depending on whether or not the driver's face orientation angle is within a threshold angle.

  According to a third aspect, in the second aspect, the warning changing unit does not cause the warning unit to perform the warning operation when the driver's face orientation angle is within the threshold angle. And

  In a fourth aspect based on the second aspect, the vehicle speed control means controls the vehicle speed of the vehicle by controlling a brake device provided in the vehicle. The vehicle further includes control changing means for changing the control of the brake device performed by the vehicle speed control means depending on whether or not the driver's face angle is within the threshold angle.

  In a fifth aspect based on the fourth aspect, the control change means performs the first control on the vehicle speed control means when the driver's face orientation angle is within the threshold angle. When the driver's face angle is outside the threshold angle, the vehicle speed control means performs second control different from the first control.

  In a sixth aspect based on the fifth aspect, the first control and the second control performed by the control change unit on the vehicle speed control unit cancel the stop state of the vehicle by the brake device. And the second control is more rapid than the first control.

  According to the first aspect of the present invention, it is possible to provide a vehicle speed control device that can prompt attention to avoid depending on the ACC control too much according to the state of the driver. That is, the manner of attention to the driver is changed according to the state of the driver's face, more specifically, according to the driver's face orientation and closed eye state. Therefore, for example, it is possible to reduce the annoyance caused by being alerted when the driver is facing the front. On the other hand, it is possible to call attention in a scene where it is necessary to call attention when the driver is watching.

  According to the second aspect, it is possible to change the manner of attention to the driver according to the face orientation angle of the driver.

  According to the third aspect, the warning changing unit does not cause the warning unit to perform a warning operation when the face orientation angle of the driver is within the threshold angle. For example, when the driver is facing the front, The annoyance caused by being cautioned can be further reduced.

  According to the fourth aspect, since the control over the brake device is changed according to the driver's face orientation angle, the driver can be alerted even using the brake device provided in the vehicle.

  According to the fifth aspect, different brake control can be performed according to the state of the driver.

  According to the sixth aspect of the invention, since the stop holding by the brake device is performed rapidly, the driver can be alerted.

The block diagram which showed an example of the structure of the vehicle speed control apparatus which concerns on one Embodiment of this invention. A flowchart showing an example of processing performed in the radar cruise ECU 1, the brake ECU 2, and the driver monitor ECU 3 The flowchart which shows an example of the process in step S25 of FIG.

  Hereinafter, the configuration and operation of a vehicle speed control device according to an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, description will be made assuming that the vehicle speed control device is installed in a passenger car (hereinafter simply referred to as the host vehicle mv). FIG. 1 is a block diagram showing an example of the configuration of a vehicle speed control device according to an embodiment of the present invention.

  As shown in FIG. 1, a vehicle speed control device according to an embodiment of the present invention includes a radar cruise ECU (Electric Control Unit) 1, a brake ECU (Electric Control Unit) 2, and a driver monitor ECU (Electric Control Unit) 3. Each ECU is connected by an in-vehicle LAN or the like.

  The radar cruise ECU 1 is connected to a radar device 4, a warning device 5, a brake pedal (device capable of outputting information indicating that the driver of the host vehicle mv has stepped on the brake pedal) 6, and the like. Further, a vehicle speed sensor 7, a brake device 8, and the like are connected to the brake ECU 2, and a camera 9 and the like are connected to the driver monitor ECU 3.

  The radar cruise ECU 1 is typically a microcomputer including a central processing unit and a readable / writable storage medium. The radar cruise ECU 1 keeps the vehicle speed of the host vehicle mv constant or uses information output from the radar device 4 to be described later as appropriate for the host vehicle mv and other vehicles traveling in front of the host vehicle mv. Control to maintain a proper inter-vehicle distance.

  Specifically, the radar cruise ECU 1 uses a signal acquired from a radar device 4 to be described later, and the position, speed, distance, etc. of a target for the host vehicle mv, that is, another vehicle traveling in front of the host vehicle mv. Target information for is calculated. For example, the radar cruise ECU 1 targets the relative distance, relative speed, relative position, and the like of the target with respect to the radar device 4 using the sum and difference between the electromagnetic wave irradiated by the radar device 4 and the received reflected wave, transmission / reception timing, and the like. Calculate as information. Then, the radar cruise ECU 1 instructs the brake ECU 3 based on the target information and automatically performs brake control of the host vehicle mv by the brake device 8. The radar device 4 and the radar cruise ECU 1 correspond to target information calculation means described in the claims, and the radar cruise ECU 1 corresponds to an example of a vehicle speed control means and an alarm change means, respectively.

  The radar device 4 is installed at a predetermined position of the host vehicle mv (for example, the center of the front part of the host vehicle mv), emits electromagnetic waves toward the outside of the host vehicle mv, and monitors the surroundings in front of the host vehicle mv. To do.

  The warning device 5 provides various information to the driver of the host vehicle mv by voice or display. Specifically, the warning device 5 notifies the driver of warnings and information according to instructions from the radar cruise ECU 1. The warning device 7 is specifically a warning light, a liquid crystal display, a head-up display, a speaker, or the like provided in the host vehicle mv. The warning device 5 corresponds to an example of warning means described in the claims.

  Specifically, the brake pedal 6 acquires information indicating that the driver of the host vehicle mv has stepped on the foot brake pedal, and can output the information to the radar cruise ECU 1, for example, a foot brake pedal of the host vehicle mv. An installed sensor or the like.

  The radar cruise ECU 1 instructs the brake ECU 2 based on the target information to automatically perform brake control of the host vehicle mv by the brake device 8, or the host vehicle mv and the host vehicle based on the target information. The control for warning the driver of the host vehicle mv by the warning device 5 when the distance to the other vehicle traveling in front of the vehicle mv is less than a predetermined distance is hereinafter referred to as collision prevention control. Sometimes called.

  Next, the brake ECU 2 will be described. The brake ECU 2 is typically a microcomputer including a central processing unit and a readable / writable storage medium. The brake ECU 2 controls the hydraulic pressure, air pressure, etc. in the master cylinder and disc brake of the host vehicle mv. The brake ECU 2 corresponds to an example of a vehicle speed control means described in the claims.

  As described above, the vehicle speed sensor 7 is connected to the brake ECU 2, and the vehicle speed sensor 7 detects the traveling speed of the host vehicle mv. Furthermore, the brake device 8 is connected to the brake ECU 2 as described above. In this description, the brake device 8 includes a brake booster (a booster device), a master cylinder, a brake hose, and the like that are mounted on the host vehicle mv, for decelerating and stopping the host vehicle mv. It is a generic term for devices.

  Here, the collision prevention control performed by the radar cruise ECU 1 will be specifically described.

  In general, the collision prevention control means that the radar cruise ECU 1 makes a constant distance between the host vehicle mv and another vehicle traveling ahead of the host vehicle mv based on information obtained from the radar device 4. Control to keep at. In addition, the radar cruise ECU 1 determines that the host vehicle mv and another vehicle traveling in front of the host vehicle mv approach each other and the host vehicle mv and the other vehicle may come into contact with each other. In this case, a warning is issued to the driver of the host vehicle mv via the warning device 5, or the brake ECU 2 is instructed to control the brake device 8 to automatically reduce the speed of the host vehicle mv. Such control performed by the radar cruise ECU 1 may hereinafter be referred to as ACC (Active Cruise Control) control.

  For the collision prevention control, not only the ACC control described above, but also, for example, the radar cruise ECU 1 determines whether an object (another vehicle, a roadside object, etc.) and the host vehicle mv are based on information obtained from the radar device 4. The driver determines whether or not there is a risk of collision, warns the driver when the risk of collision with the object is high, and controls the brake device 8 provided in the host vehicle mv so that the driver So-called collision avoidance control that assists the brake operation to be performed is also included. When the radar cruise ECU 1 determines that a collision between the object and the host vehicle mv is unavoidable, the radar cruise ECU 1 winds up a seat belt (not shown) or drives the seat, thereby driving the host vehicle mv. This includes so-called collision damage reduction control that increases the restraint of passengers and reduces collision damage. Such control may be referred to as PCS (Pre-Clash Safety) control.

  For example, regarding the ACC control, it is assumed that the host vehicle mv and another vehicle traveling in front of the host vehicle mv are both traveling at 30 km / h, and then traveling in front of the host vehicle mv. Suppose that the other vehicle is slowing down for some reason. In the following description, another vehicle traveling in front of the host vehicle mv may be simply referred to as a preceding vehicle. At this time, if the host vehicle mv is too close to the preceding vehicle, the radar cruise ECU 1 instructs the brake ECU 2 to control the brake device 8 to automatically reduce or stop the speed of the host vehicle mv. To do. The state in which the host vehicle mv is automatically stopped by the ACC control and the stop state of the host vehicle mv is continued may be simply referred to as stop holding hereinafter.

  The ACC control supports safe driving of the driver who drives the host vehicle mv. For example, even in the case of the above-described example, the driver himself performs a brake operation so that the host vehicle mv is a preceding vehicle. Even if the host vehicle mv is stopped and held automatically by the brake device 8 (the host vehicle mv is stopped by the control of the brake device 8), the driver himself steps on the brake to drive the host vehicle mv. It is desirable to stop the operation.

  However, for example, when the driver of the host vehicle mv is looking aside or looking away, the driver of the host vehicle mv may not notice the preceding vehicle that is approaching. Therefore, the vehicle speed control apparatus according to the present embodiment includes a driver monitor ECU 3 and the like, and details thereof will be described later, but the radar cruise ECU 1 performs various controls described later based on information obtained from the driver monitor ECU 3.

  Returning to the description of FIG. 1, the driver monitor ECU 3 is typically a microcomputer including a central processing unit and a readable / writable storage medium. The driver monitor ECU 3 processes the image captured by the camera 9 to generate information related to the driver's face (specifically, the driver's face orientation, eye closing time, eye closing time, etc.), and outputs the information to the radar cruise ECU 1 To do.

  The camera 9 is, for example, a CCD camera, a CMOS camera, an infrared camera, or the like. The camera 9 is installed, for example, on a steering column in order to capture the face of the driver seated in the driver's seat. For example, the camera 9 captures the driver's face at predetermined time intervals, and outputs the captured image to the driver monitor ECU 3.

  FIG. 2 is a flowchart illustrating an example of processing performed in the radar cruise ECU 1, the brake ECU 2, and the driver monitor ECU 3 of the vehicle speed control device according to the present embodiment.

  2 is performed by executing a predetermined program stored in a storage unit (not shown) provided in each of the radar cruise ECU 1, the brake ECU 2, and the driver monitor ECU 3. In the flowchart shown in FIG. The process shown in the flowchart of FIG. 2 is started when the power supply of the vehicle speed control device is turned on (for example, the ignition switch of the host vehicle mv on which the vehicle speed control device is mounted), and is turned off. finish. The ignition switch is hereinafter abbreviated as IG.

  In step S21, the radar cruise ECU 1 determines whether or not the IG of the host vehicle mv is ON. If it is determined that IG is ON (YES), the process proceeds to the next step S22. On the other hand, when the radar cruise ECU 1 determines that the IG of the host vehicle mv is not ON, that is, the IG is OFF (NO), the processing in the flowchart ends.

  In step S22, the radar cruise ECU 1 determines whether or not to perform collision prevention control, particularly ACC control. And radar cruise ECU1 advances a process to the following step S23, when the judgment of the said step S22 is affirmed (YES). On the other hand, when the radar cruise ECU 1 denies the determination in step S22 (NO), the radar cruise ECU 1 returns the process to step S21. The determination in step S22 is, for example, information obtained by the user of the host vehicle mv pressing a switch (a switch for executing (starting) or stopping ACC control) provided in the host vehicle mv. It can be judged by such as.

  More specifically, for example, when the radar cruise ECU 1 obtains information indicating that the ACC control switch is pressed by the driver, the radar cruise ECU 1 may affirm the determination in step S22. If the determination in step S22 is affirmative (YES), the ACC control is performed on the host vehicle mv.

  Proceeding to the next step S23, the radar cruise ECU 1 acquires vehicle information. Specifically, the radar cruise ECU 1 acquires a signal from the radar device 4 and acquires the vehicle speed of the host vehicle mv output from the vehicle speed sensor 7 from the brake ECU 2. The radar cruise ECU 1 then proceeds to the next step S24.

  In step S24, the radar cruise ECU 1 determines whether or not the host vehicle mv is just before stopping. If the determination in step S24 is affirmative (YES), the process proceeds to the next step S25. On the other hand, the radar cruise ECU 1 returns the process to step S23 when the determination in step S24 is negative (NO). The determination in step S24 will be specifically described. For example, immediately before stopping the vehicle, for example, the brake device 8 automatically controls the brake of the host vehicle mv according to an instruction from the brake ECU 3, and the host vehicle mv. Is a situation that is trying to stop. More specifically, in the present description, immediately before stopping, the vehicle speed of the host vehicle mv is not 0 km / h (stopped state), but the host vehicle mv decelerates and is about to stop (for example, the vehicle speed of 5 km / h). Degree) situation.

  Further, as a specific scene in which the determination in step S24 is affirmed, for example, the radar cruise ECU 1 determines that the host vehicle mv is too close to the preceding vehicle based on information output from the radar device 4, and brakes. Examples include a case where the ECU 3 is instructed to automatically perform brake control of the host vehicle mv by the brake device 8 and the host vehicle mv is about to decelerate or stop.

  The radar cruise ECU 1 may determine the determination in step S24 in relation to the preceding vehicle. For example, the radar cruise ECU 1 is based on information obtained from the radar device 4, that is, based on the relative distance, relative speed, relative position, and the like between the host vehicle mv and another vehicle. It is determined whether the distance is kept constant or whether the vehicle is too close to the preceding vehicle. That is, for example, when the preceding vehicle accelerates after the preceding vehicle decelerates and approaches the own vehicle mv, the distance between the own vehicle mv and the preceding vehicle may be kept constant. Conceivable. Accordingly, even in a situation where the host vehicle mv is decelerating and is about to stop, in this case, for example, when the preceding vehicle is accelerated, the radar cruise ECU 1 negates (NO) the determination in step S24. May be.

  Proceeding to step S25, the driver monitor ECU 3 performs image processing. Hereinafter, the image processing in step S25 will be described with reference to FIG. FIG. 3 is a flowchart showing an example of processing in step S25 of FIG.

  First, in step S31 of FIG. 3, the driver monitor ECU 3 acquires an image captured by the camera 9. Then, the driver monitor ECU 3 advances the processing to the next step S32.

  In step S <b> 32, the driver monitor ECU 3 detects the face width of the driver in the image captured by the camera 9. Specifically, the driver monitor ECU 3 detects a face width by searching for a contour portion of the driver's face in the image, for example, by an edge extraction process using a known Sobel operator. And driver monitor ECU3 advances a process to the following step S33.

  In step S33, the driver monitor ECU 3 estimates the positions of the driver's eyes, nose, and mouth (hereinafter referred to as face parts) in the image captured by the camera 9, using the face width detected in step S32. For example, the driver monitor ECU 3 uses the data indicating the face width detected in step S32 and the face information (such as a template image) stored in the storage unit (not shown) of the driver monitor ECU 3 to A range where each face part is expected to be present is set.

  And driver monitor ECU3 performs the process which extracts an edge line with respect to the image in the set range, The said edge line is used using the template image of each face part stored in the memory | storage part of driver monitor ECU3. Pattern matching is performed on the extracted image, the position of each face part is estimated, and the process proceeds to the next step S34.

  In step S34, the driver monitor ECU 3 obtains the center line of the face. As an example of processing, the driver monitor ECU 3 obtains the center line of the face in the image based on the eye, nose, and mouth positions estimated in step S33. And driver monitor ECU3 advances a process to the following step S35.

  In step S35, the driver monitor ECU 3 calculates the driver's face orientation angle θR or θL, outputs the calculation result to the radar cruise ECU 1, and ends the process of the flowchart shown in FIG.

  The driver's face orientation angle will be described. First, it is assumed that the driver's head has a cylindrical shape with the top of the head. The driver's face rotates around the center line of the cylindrical head. Here, the driver's face orientation angle is θ, and the state of facing the front with respect to the camera 9 is θ = 0 °. Then, the driver monitor ECU 3 calculates the face orientation angle θR when the driver faces the right with respect to the camera 9, and calculates the face orientation angle θL when the driver faces the left. The face orientation angles θR and θL are set with reference to the optical axis (not shown) of the camera 9.

  In the state where the driver is seated in the driver's seat of the host vehicle mv, the value of the face angle θR increases as the driver faces the front right side of the host vehicle mv, and the value of the face direction angle θL increases as the driver faces the left side. Note that the above-described method for calculating the face direction angle is an example, and the method for calculating the face direction angle is not limited to the above example, and a conventionally known method may be used.

  Returning to the description of the flowchart of FIG. 2, in step S <b> 26 of FIG. 2, the radar cruise ECU 1 refers to the driver's face orientation angle θR or θL output from the driver monitor ECU 3, and the driver's face orientation is front or not. Determine whether. If the determination in step S26 is affirmative (YES), the process proceeds to step S27. On the other hand, the radar cruise ECU 1 advances the process to step S28 if the determination in step S26 is negative (NO).

  Hereinafter, the determination in step S26 will be specifically described. As described above, the value of the face angle θR increases as the driver faces the front right side of the host vehicle mv, and the value of the face angle θL increases as the driver faces the left side. That is, it is considered that as the values of the angles θR and θL become larger, the driver is not facing the front, in other words, the possibility of looking aside or looking away is high. Therefore, for example, the angles ΘR and ΘL are set as threshold angles.

  When the driver's face orientation angles θR and θL deviate from the respective threshold angles, that is, when θR> ΘR or θL> ΘL, the driver is looking aside or looking away, in other words, the driver's face orientation Judge that is not the front. More specifically, for example, it is assumed that the threshold angle values, that is, the values of the angles ΘR and ΘL, are temporarily set as ΘR = 20 ° and ΘL = 20 °, respectively. When the driver face orientation angle θR output from the driver monitor ECU 3 is θR = 25 °, or when the driver face orientation angle θL is θR = 30 °, the driver's face It is determined that the direction is not the front (NO in step S26).

  In step S28 in which it is determined in step S26 that the driver's face is not in front, the radar cruise ECU 1 instructs the warning device 5 to warn the driver of the host vehicle mv with various information by voice or display. And encourage the driver to face the front. The warning to the driver may be continued until the driver performs a brake operation and / or until the ACC control is released.

  Furthermore, in the above-described example, only when it is determined that the driver's face direction is not the front, the radar cruise ECU 1 instructs the warning device 5 to warn the driver of the host vehicle mv with various information by voice or display. went. However, the present invention is not limited to this. For example, even when step S26 affirms the determination (YES), a warning may be given. That is, the driver recognizes that the host vehicle mv is approaching the preceding vehicle and intends to perform braking, but may give a warning in order to further promote the driver's own brake operation. The warning in this case is preferably a warning different from the warning in step S28. That is, the warning in this case is that the driver is facing the front and sufficiently recognizes that the own vehicle mv is approaching the preceding vehicle. Therefore, the driver is compared with the warning in step S28. For example, a warning with a changed pitch, volume, warning timing, or the like may be used without feeling bothersome.

  In step S27 in which it is determined in step S26 that the driver is facing the front, the radar cruise ECU 1 acquires information from, for example, a sensor or the like installed on the foot brake pedal 6 of the host vehicle mv. It is determined whether or not the driver of the vehicle mv has depressed the foot brake pedal. In other words, the radar cruise ECU 1 determines whether or not a brake operation has been performed by the driver in step S27. And radar cruise ECU1 advances a process to step S21, when the judgment of the said step S27 is affirmed (YES). On the other hand, the radar cruise ECU 1 advances the process to step S29 when the determination in step S27 is negative (NO).

  Note that the case where the radar cruise ECU 1 affirms the determination in step S27 means, for example, that the driver feels that the host vehicle mv is approaching the preceding vehicle and brakes or the driver is looking aside or looking away. Although the vehicle mv did not notice that it was approaching the preceding vehicle, the driver turned to the front by the warning in step S28 and felt that the host vehicle mv was approaching the preceding vehicle, etc. Conceivable.

  Thus, when the own vehicle mv is approaching the preceding vehicle and the driver is facing the front, no warning is given. That is, although the driver recognizes that the host vehicle mv is approaching the preceding vehicle and intends to brake, the driver does not feel bothered by the warning. On the other hand, when the driver is looking aside or looking away and the own vehicle mv is approaching the preceding vehicle, the above warning is given, so that safe driving can be supported.

  In step S26, the radar cruise ECU 1 determines whether or not the driver's face is front, but the present invention is not limited to this. For example, although the driver did not notice that he was approaching the preceding vehicle, the driver noticed in front by the warning in step S28 and felt that the host vehicle mv was approaching the preceding vehicle. It is not limited to when the driver is not facing the front. For example, when the driver's face is in front but the driver is asleep (when eyes are closed), the driver does not notice that he is approaching the preceding vehicle, and the driver notices the warning in step S28. It is also conceivable that the host vehicle mv feels that it is approaching the preceding vehicle and brakes are performed.

  Therefore, the radar cruise ECU 1 determines whether or not the driver's face direction is the front, and for example, the opening degree of the driver's eyes, that is, the distance between the upper and lower eyelids of the driver is a predetermined distance. You may add the judgment whether it is above.

  Note that the driver monitor ECU 3 may calculate the distance between the upper eyelid and the lower eyelid of the driver from the image captured by the camera 9 using a known method, for example, the following method.

  The driver monitor ECU 3 estimates the position of the driver's eyes using the detected face width, detects the upper eyelid and the lower eyelid by pattern matching or the like, and calculates the distance between the upper eyelid and the lower eyelid. Then, the radar cruise ECU 1 may determine whether the distance between the upper heel and the lower heel is equal to or greater than a predetermined distance. Then, if the distance between the upper and lower eyelids of the driver is less than a predetermined distance, the driver monitor ECU 3 determines that the driver is sleeping (closed eyes), for example. May be warned.

  Returning to the description of the flowchart in FIG. 2, in the next step S <b> 29 in which it is determined that the brake operation has not been performed by the driver in step S <b> 27, the radar cruise ECU 1 determines whether or not the host vehicle mv has stopped. Specifically, for example, the radar cruise ECU 1 acquires the vehicle speed of the host vehicle mv output from the vehicle speed sensor 7 from the brake ECU 2, and determines whether the host vehicle mv has stopped. And radar cruise ECU1 advances a process to step S210, when the judgment of the said step S29 is affirmed (YES). As described above, as a specific scene in step S29, a brake operation by the driver is not performed. Specifically, the radar cruise ECU 1 instructs the brake ECU 2 by the ACC control to provide a brake device. 8 is controlled and the own vehicle mv is automatically stopped.

  On the other hand, the radar cruise ECU 1 returns the process to step S27 when the determination in step S29 is negative (NO).

  Although not shown in the flowchart of FIG. 2, the radar cruise ECU 1 makes a warning again (for example, similar to step S28 above) after affirmative (YES) and negative (NO) determination in step S29. Warning). In this way, for example, even when the driver is looking aside or looking away, it is expected that the driver will turn to the front by a warning or that the driver himself will perform a brake operation.

  In step S210, the radar cruise ECU 1 refers to the driver's face angle θR or θL output from the driver monitor ECU 3, and determines whether or not the driver's face direction is the front. If the determination in step S210 is affirmed (YES), the process proceeds to step S211. On the other hand, the radar cruise ECU 1 advances the process to step S212 when the determination in step S210 is negative (NO). The processing in step S210 has been described in step S26 and will not be repeated.

  Even in step S210, it may be determined whether or not the opening degree of the driver's eyes, that is, the distance between the upper and lower eyelids of the driver is equal to or greater than a predetermined distance. Good.

  Next, the radar cruise ECU 1 instructs the brake ECU 2, and the brake ECU 8 is controlled by the brake ECU 2. Specifically, the host vehicle mv is stopped by the ACC control in the processing so far, but the processing after step S210 is performed based on the determination in step S210, that is, whether the driver's face direction is the front or not. The release operation for stopping and holding the brake device 8 differs depending on the type.

  Here, the operation of the brake device 8 when the radar cruise ECU 1 determines that the driver's face is in front in step S210 is referred to as brake release (A) (step S211). On the other hand, the operation of the brake device 8 when the radar cruise ECU 1 determines in step S210 that the driver's face is not front is referred to as brake release (B) (step S212). Hereinafter, the control of the brake device 8 performed by the brake ECU 2 instructed by the radar cruise ECU 1, that is, the brake release (A) and the brake release (B) will be described.

  First, the brake release (A) will be described. As described above, the brake release (A) is a process that is performed next when the driver's face is in front in step S210. Therefore, the driver recognizes that the host vehicle mv is approaching the preceding vehicle, and the driver himself is assumed to perform the brake operation. Therefore, in the brake release (A), the stop holding performed by the brake device 8 is performed. Release gently.

  On the other hand, the brake release (B) is a process that is performed next when the driver's face orientation is not the front in step S210. Therefore, since the driver may not recognize that the host vehicle mv is approaching the preceding vehicle, the brake device 8 performs the brake release (B) as compared with the brake release (A). Releases the held stop suddenly. This can also prompt the driver to call attention.

  Returning to the explanation of FIG. 2, in step S213, the radar cruise ECU 1 determines whether or not the IG of the host vehicle mv is turned off. If it is determined that IG is OFF (YES), the processing in the flowchart is terminated. On the other hand, when the radar cruise ECU 1 determines that the IG of the host vehicle mv is not turned off (NO), the radar cruise ECU 1 returns the process to step S22.

  As described above, according to the vehicle speed control device of the present embodiment, it is possible to change the mode of attention to the driver in accordance with the state of the driver's face, more specifically, according to the driver's face orientation and closed eye state. . Therefore, for example, it is possible to reduce the annoyance caused by being alerted when the driver is facing the front. On the other hand, it is possible to call attention in a scene where it is necessary to call attention when the driver is watching.

  Furthermore, according to the vehicle speed control device according to the present embodiment, when the stop holding by the brake device 8 is released, the release method differs depending on the state of the driver. Specifically, in a scene where it is necessary to call attention when the driver is looking aside, the stop holding by the brake device 8 is performed rapidly, so the driver can be alerted. Further, in the case of a brake device in which the stop holding after the host vehicle mv is automatically decelerated cannot be maintained for a certain period of time, it may be necessary to release the stop holding. However, according to the vehicle speed control device according to the present embodiment, even if the host vehicle mv is equipped with such a brake device, the release method is changed depending on the driver's state, thereby allowing the driver to In situations where attention is required, attention can be urged.

  The aspect demonstrated by the said embodiment shows a specific example only, and does not limit the technical scope of this invention at all. Therefore, any configuration can be adopted within a range where the effect of the present application is achieved.

  The vehicle speed control device according to the present invention is useful for a vehicle speed control device that recognizes other vehicles ahead of the vehicle and controls the movement of the vehicle so as to maintain a predetermined distance.

1 ... Radar cruise ECU
2 ... Brake ECU
3. Driver monitor ECU
4 ... Radar device 5 ... Warning device 6 ... Brake pedal 7 ... Vehicle speed sensor 8 ... Brake device 9 ... Camera

Claims (6)

A vehicle speed control device that recognizes a moving body in front of a vehicle and controls the vehicle speed so that the moving body and the vehicle maintain a predetermined distance,
Target information calculating means for calculating information regarding movement of the moving body as target information by irradiating the moving body in front of the vehicle with electromagnetic waves and receiving a reflected wave reflected from the moving body;
Face information calculating means for capturing an image of the face of the driver of the vehicle and calculating information about the driver's face as face information using the captured image;
Vehicle speed control means for controlling the vehicle speed of the vehicle based on the target information;
Warning means for performing a warning operation to the driver when the vehicle stops by the vehicle speed control means;
A vehicle speed control apparatus comprising: a warning changing unit that changes a mode of the warning operation performed by the warning unit based on the face information. The face information calculation means calculates a face direction angle of the driver with respect to an imaging direction as the face information,
2. The vehicle speed control according to claim 1, wherein the warning changing unit changes a mode of the warning operation performed by the warning unit depending on whether or not a face angle of the driver is within a threshold angle. apparatus.   The vehicle speed control device according to claim 2, wherein the warning changing unit does not cause the warning unit to perform the warning operation when the driver's face orientation angle is within the threshold angle. The vehicle speed control means controls the vehicle speed of the vehicle by controlling a brake device provided in the vehicle,
The vehicle speed control device according to claim 2, further comprising control change means for changing control of the brake device depending on whether or not the driver's face orientation angle is within the threshold angle.   The control change means performs first control on the vehicle speed control means when the driver's face direction angle is within the threshold angle, and the driver's face direction angle is outside the threshold angle. 5. The vehicle speed control device according to claim 4, wherein if there is, the vehicle speed control means performs a second control different from the first control. 6.   The first control and the second control performed by the control change unit with respect to the vehicle speed control unit are controls for releasing the stop state of the vehicle by the brake device. 6. The vehicle speed control device according to claim 5, wherein the control of No. 2 is abrupt.

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