JP2008186384A - Controller for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a deterioration in safety caused by a change of a slope of a road surface. <P>SOLUTION: In a vehicle 10, a safety system 500 operates when a collision flag is on. The collision flag is set by collision flag setting processing. In the processing, an object corresponding to reflection intensity is detected as an obstacle when reflected wave intensity Pr obtained when a millimeter wave emitted from a front millimeter wave radar is reflected from a front object is equal to or larger than a threshold S1. When the obstacle is not a static object or when an absolute value of a difference between a gradient value G0 of a self-vehicle and a front gradient value Gf is less than a reference value C2, a threshold Ct of a collision predicted time TTC when the collision flag is on is set to Ct1. On the other hand, when the obstacle is a static object and when the absolute value of a difference between the gradient value G0 of the self-vehicle and the front gradient value Gf is equal to or larger than the reference value C2, the relevant threshold Ct is set to Ct2 smaller than Ct1 to make the safety system 500 difficult to operate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technical field of a vehicle control device that controls a vehicle to cope with, for example, a collision with an obstacle.

  As a conventional technique related to this type of apparatus, a technique considering a road gradient has been proposed (see, for example, Patent Document 1). According to the vehicular image processing device disclosed in Patent Document 1, the gradient change point ahead of the host vehicle is detected from the navigation information, and the image processing area for recognition of the preceding vehicle is corrected by the road curvature radius. It is said that the position of the car can be detected more accurately.

  In addition, a technique for correcting a narrowed-down area, which is an image acquisition area for detecting an object, in consideration of a pitch angle of an automobile and a change in road gradient from navigation information and infrastructure information has been proposed (for example, patents). Reference 2).

  In addition, a technique has been proposed in which the threshold value is increased in order to correct the detection area to the insensitive side according to the tilt angle when a change in the tilt angle of the vehicle is detected within a predetermined time (see, for example, Patent Document 3). ).

JP 2005-148816 A JP 2003-237509 A JP 2003-194939 A

  When the slope of the road surface changes, it is not easy to recognize the target object, for example, the road surface itself, a pattern such as a pedestrian crossing, or a structure is likely to be recognized as the target object, which may easily cause an erroneous detection of the target object. In the above-described various conventional techniques, an image processing area for detecting an object (including the above-described image acquisition area or detection area) is corrected by reflecting a road surface gradient, a vehicle inclination, a vehicle height, or the like. However, such erroneous detection occurs because it is relatively easy to determine that the object is an object due to a change in gradient, rather than depending on an image processing region or the like. Therefore, in the conventional technique, an erroneous detection of the target object may occur in the corrected image processing area. On the other hand, this type of device may be provided with various systems to improve the safety of the vehicle when there is a possibility of collision between the vehicle and the obstacle. May cause malfunction of these systems. That is, the conventional technique has a technical problem that the safety of the vehicle may be lowered depending on the change in the slope of the road surface.

  This invention is made | formed in view of the problem mentioned above, and makes it a subject to provide the control apparatus of the vehicle which can suppress the fall of the safety | security resulting from the gradient change of a road surface.

  In order to solve the above-described problems, a vehicle control apparatus according to the present invention includes a detection unit that can detect an object in a front detection range, and a predetermined type of safety system that can improve collision safety during operation. A vehicle control apparatus for controlling a vehicle equipped with first determination means for determining whether or not the detected object is an object, and that the detected object is the object When the determination is made, the operation control means for operating the safety system according to a predetermined type of operation criterion, the first specifying means for specifying the first gradient indicating the gradient at the traveling position of the vehicle, A second specifying unit that specifies a second gradient that represents a gradient at a forward position; and a changing unit that changes the operation reference according to a relative relationship between the specified first and second gradients. Characteristic To.

  The vehicle according to the present invention is provided with detection means that can take various aspects such as radio wave radar, laser radar, sonar, image sensor, or video camera, and an object in a predetermined detection range set in front of the vehicle. Is detected as, for example, reflected radio waves, reflected laser light, reflected sound, or an image.

  The vehicle according to the present invention further includes various DSS (Driving Support System), for example, various safety systems such as PCS (Pre Crush Safety system), more specifically, For example, PB (Pre-crush Brake: Pre-crash Brake Control), PSB (Pre-crush Brake Assist: Pre-Crash Brake Assist), PBA (Pre-crush Brake Assist) Suspension control, output control of various alarm devices, various steering support control using EPS (Electronic Power Steering), for example, headrest control for head protection, seat control for human body protection , Various physical, mechanical, mechanical or electrical systems to realize various controls such as active hoods or active bumpers Or, further equipped with a driving load reduction system such as ACC (Adaptive Cruise Control), LKA (Lane Keeping Assist), or IPA (Intelligent Parking Assist) In operation, the collision safety in the vehicle is improved.

  The “collision safety” described here is intended to include safety in the sense of avoiding collision with an obstacle while including safety at the time of collision with an obstacle.

  According to the vehicle control device of the present invention, the first control unit can take various forms such as various processing units such as an ECU (Electronic Control Unit), various controllers, various computer systems such as a microcomputer device, and the like. Is determined to be capable of detecting an object with a degree of reliability that allows at least a practically significant benefit from being detected, for example, among the detected objects, and depending on the mode of the detection means, For example, it is determined whether or not the detected object is a target according to a predetermined type of determination criterion that can take various aspects such as various index values.

  Here, the “object” in the present invention is an object related to whether or not various DSSs can be operated, and the concept is included as a part of the object detected by the detection means. For example, the target object is a vehicle that exists in a detection range set in front of the vehicle, for example, whether it is stopped or traveling (hereinafter referred to as “front vehicle” as appropriate), or the course of the vehicle. It refers to the fallen object, placed object, or installed object.

  On the other hand, according to the vehicle control device of the present invention, when it is determined that the detected object is a target object during operation, various processing units such as an ECU, various controllers, a microcomputer device, etc. The safety system described above is operated according to a predetermined type of operation standard by operation control means that can take the form of various computer systems and the like.

  Here, the “operation standard” according to the present invention may cause a collision or may be difficult to avoid or avoid a collision in, for example, a front region of the vehicle, more specifically, for example, on the course of the vehicle. Including the timing and scale of operation of the safety system when the above safety system is activated regardless of the driver's braking operation (ie, automatically) when the presence of an obstacle to be detected is detected. Control conditions.

  By controlling the safety system according to such an operation standard, for example, when the relative distance between the obstacle and the vehicle becomes a predetermined value or less, or when the vehicle travels at the current vehicle speed, it collides with the obstacle. When the time until the time becomes less than a predetermined value, for example, a braking force is applied to the wheels, the collision between the vehicle and the obstacle is avoided, the shock at the time of the collision is buffered, or the vehicle before and after the collision The behavior change is suppressed, and safer driving in the vehicle can be ensured. That is, collision safety can be improved.

  In particular, depending on the road surface gradient in the detection range, erroneous detection of an object is likely to occur as described above. More specifically, for example, various patterns such as road surfaces themselves, pedestrian crossings or road signs, or various structures such as overbridges, guardrails, installation signs, bulletin boards, tunnels, etc. that should not be judged as objects. A stationary object can be easily identified as an object. When such a false detection occurs, the safety system is controlled by the operation control means, and the safety system including, for example, the braking means, for example, is not in a condition that should be originally operated, for example, at a timing that is not expected by the driver. By operating at an inappropriate timing, the safety of the vehicle may be impaired.

  Therefore, in the vehicle control apparatus according to the present invention, a decrease in safety is suppressed in consideration of changes in the road surface gradient as follows. That is, according to the control apparatus for a vehicle according to the present invention, at the time of its operation, for example, by the action of the first specifying means that can take the form of various processing units such as an ECU, various controllers or various computer systems such as a microcomputer device, For example, the first gradient representing the gradient at the traveling position of the vehicle is specified via a car navigation device, an inclinometer, an inclination angle sensor, or the like as appropriate. In addition, according to the object detection device of the present invention, the operation of the second specifying means that can take the form of various processing units such as an ECU, various controllers, various computer systems such as a microcomputer device, etc. A second gradient representing the gradient at the front position of the vehicle is identified.

  Here, the “front position” according to the specifying means may be a position within the detection range of the detection means or a position outside the detection range as long as it is ahead of the traveling position of the vehicle. The “gradient” according to the present invention includes a wide angle including, for example, an inclination angle with respect to a preset reference plane such as a horizontal plane or a vertical plane, and an index value having a one-to-one or many-to-one relationship with the inclination angle. It is a concept.

  Note that “specific” in the present invention refers to, for example, detecting directly or indirectly as a physical numerical value or an electrical signal or the like corresponding to a physical numerical value via some detection means, appropriate storage means, etc. Selecting a corresponding numerical value from a map or the like stored in the map, or estimating through such selection, a preset algorithm based on the detected physical numerical value or electrical signal or the selected or estimated numerical value It is a broad concept encompassing derivation or estimation according to a calculation formula or the like, or simply acquiring a value detected, selected, estimated or derived as an electric signal or the like.

  On the other hand, the vehicle control device according to the present invention is further provided with changing means that can take the form of various processing units such as ECUs, various controllers or various computer systems such as microcomputer devices, etc. The aforementioned operation criteria are changed according to the relative relationship between the first and second gradients specified by the second specifying means. When the operating standard is changed, the operation control means naturally controls the safety system in accordance with the changed operating standard.

  Here, the “relative relationship” is defined by the first gradient and the second gradient, for example, a qualitative relationship in which the first gradient is larger or smaller, or the difference between the first gradient and the second gradient. This includes a relationship that has a causal relationship with at least the occurrence of erroneous detection of an object or the occurrence of malfunction of a safety system, including an equal quantitative relationship. For example, the changing means, for example, when a certain index value that defines the relative relationship is equal to or greater than a predetermined threshold value, for example, the timing at which the safety system is activated, the operation scale (for example, the magnitude of the braking force, the rising characteristics, etc.) The operation reference is changed by changing the control amount in a binary manner or by changing the control amount continuously or stepwise according to an index value that defines the relative relationship.

  The “change” according to the present invention means that a predetermined basic operation standard, preferably the above-described control amount or the like is subjected to some numerical operation or logical operation processing, or is set in advance, for example. Various control variables can be set separately from the basic control variable as a result of numerical calculation independent of the basic control variable according to the appropriate algorithm, or by selecting a corresponding value from an appropriate map, etc. It is a concept that encompasses setting etc.

  As described above, the operating standard is an element that determines the operating state of the safety system. By making the change, for example, the safety system can be operated earlier, or the operation of the safety system can be delayed. Is also possible. Therefore, for example, in the basic state (or a state that can be regarded as such), the safety system is set to be relatively easy to operate, and according to the relative relationship (for example, significant between the first gradient and the second gradient). When the operating standard is changed so that it becomes difficult to operate the safety system as appropriate, or, for example, in the basic state, the safety system is set to be relatively difficult to operate. In accordance with the relative relationship (for example, when a difference between the first gradient and the second gradient is not recognized), the operation standard is changed so that the safety system can be operated appropriately. Therefore, it is possible to reduce and ideally eliminate the influence of the change in the road surface gradient on the operating state of the safety system. That is, according to the vehicle control apparatus of the present invention, the malfunction of the safety system is suppressed, and the decrease in the safety of the vehicle is suppressed.

  In one aspect of the control apparatus for a vehicle according to the present invention, the changing means operates so that the safety system becomes difficult to operate when the degree of deviation between the first gradient and the second gradient is large. Change the standard.

  According to this aspect, when the degree of divergence between the first gradient and the second gradient is large, the operation reference is changed by the changing means so that the safety system becomes difficult to operate. In situations where the road surface gradient is changing significantly, for example, the road surface itself, various patterns such as pedestrian crossings or road signs, or stationary objects such as various structures such as overbridges, guardrails, installation signs, bulletin boards or tunnels, etc. Even if it is mistakenly detected as an object, the safety system is difficult to operate, so that a reduction in safety is suppressed. Note that “when the degree of deviation is large” does not necessarily indicate all such cases, and at least a part of such cases, for example, the difference between the second gradient and the first gradient is predetermined. This is to the extent that it may be greater than or equal to or less than or equal to a predetermined value.

  In addition, the change made “so that the safety system is difficult to operate” means that various modes can be inevitably taken according to the contents of the operation standard, and the safety system is relatively difficult to operate relatively. The aspect is not limited at all as long as the decrease in safety due to the false detection of the object can be suppressed to some extent. Note that the safety system is difficult to operate is not a property that depends solely on whether or not the safety system is operated, but is a concept including a state in which the influence of the safety system on the vehicle is difficult to be realized. Therefore, even if there is no significant difference in the operation timing of the safety system itself, for example, as long as the influence of the safety system is relatively suppressed, it is a category “not easily operated” according to the present invention.

  In this aspect, the changing means may change the operation reference when the absolute value of the difference between the first gradient and the second gradient that defines the degree of deviation is equal to or greater than a predetermined value. Good.

  According to this aspect, the absolute value of the difference between the first gradient and the second gradient is referred to as the index value that defines the degree of deviation described above, and the operation standard is changed when the difference is equal to or greater than a predetermined value. The The absolute value of the difference is a value that becomes significantly larger when the front side of the vehicle is an uphill road or a downhill road having a relatively large inclination angle compared to the current position, and is determined as an original object. This is an index value that can be correlated with the possibility of discriminating an object that does not need to be detected as an object. Therefore, the absolute value of the difference is set in advance as a value that can be practically manifested by a decrease in safety due to erroneous detection of an object, for example, experimentally, empirically, theoretically, or based on simulation. When the value is equal to or higher than a predetermined value, various index values that define the operation reference are changed, for example, in a binary manner, stepwise, or continuously, so that a reduction in safety is efficiently suppressed.

  In another aspect of the vehicle control device according to the present invention, the operation standard is changed so that the safety system becomes difficult to operate. The safety system includes braking means capable of applying a braking force to the vehicle, The changing means includes (i) the timing at which the braking force is applied is delayed, (ii) the braking force to be applied is reduced, or (iii) the increase rate of the braking force at the start of the application. The operation standard is changed so as to decrease the value.

  In this case, the safety system includes braking means such as a brake device that can apply a braking force to the vehicle, and control of PB, PBA, etc. in the PCS described above can be realized through the application of the braking force to the vehicle. . At this time, the changing means reduces the applied braking force so that the timing of applying the braking force is delayed, or reduces the increase rate of the braking force at the start of applying (for example, remarkably controlling). Since the operation standard is changed (so that the gradient of the power rise is relatively gentle), it is difficult for the malfunction of the braking means that can significantly reduce the safety of the vehicle to become obvious, and the reduction in safety is effective. To be suppressed.

  In another aspect of the vehicle control device according to the present invention, the vehicle control device further includes second determination means for determining whether or not the detected object is a stationary object, and the changing means is configured to detect the detected object. The operation reference is changed when it is determined that the object is the stationary object.

  According to this aspect, for example, the relative speed between the vehicle and the detected object can be adjusted by the second determination means that can take the form of various processing units such as an ECU, various controllers or various computer systems such as a microcomputer device. Based on this, the object detected by the detection means is a stationary object as a concept including various patterns such as road surfaces, pedestrian crossings or road signs, or various structures such as overbridges, guardrails, installation signs, bulletin boards or tunnels ( In other words, it is determined whether or not the relative speed with respect to the road surface is zero or an object that can be regarded as zero.

  Here, the changing means changes the operation reference when it is determined that the detected object is a stationary object. That is, according to this aspect, the operation reference is changed at least preferentially (preferably only for a stationary object) with respect to a stationary object. In view of the installation purpose of the vehicle control device according to the present invention, an object that is not a stationary object (that is, an object having a relative speed with respect to the road surface, and at least a forward vehicle (including an oncoming vehicle) with a high probability in practice). It is an object that may need to operate a safety system from the viewpoint of ensuring safety, in other words, an object that is unlikely to be falsely detected as a target object, is there. Accordingly, when the detected object is a stationary object, at least priority is given to the change of the operation standard, thereby erroneously determining that the road surface and various structures are objects (i.e. The safety system can be quickly activated for situations where the safety system should be operated according to the operating standards, while reducing the possibility (or frequency or degree) of the malfunction of the safety system based on the detection) A very high profit can be enjoyed.

  In another aspect of the vehicle control apparatus according to the present invention, the detection means emits a radio wave having a predetermined wavelength in the detection range and receives a reflected wave formed by reflecting the emitted radio wave on the object. A radar capable of detecting the object, wherein the first discrimination means detects the detected object based on a comparison between an index value corresponding to the intensity of the received reflected wave and a first threshold value. It is determined whether or not is an object.

  According to this aspect, the detection means is configured to include a radar configured to be able to emit a radio wave such as a millimeter wave and to be able to receive a reflected wave reflected from an object existing in the detection range. And is detected based on a comparison between the first threshold and an index value as a concept including the intensity of the reflected wave or some index value that may have a one-to-one relationship with the intensity of the reflected wave. It is determined whether or not the detected object is a target object. Therefore, according to this aspect, the object can be detected quickly and accurately, and the effect of improving the collision safety related to the control of the safety system according to the operation standard is remarkably exhibited.

  The radio wave in this aspect is strictly a concept including electromagnetic waves having a frequency of 30 Hz to 3 THz. However, as a preferable aspect, a millimeter wave of 30 to 300 GHz (in the object detection device according to the present invention). Furthermore, the 76 to 77 GHz band is used remarkably) or infrared rays or the like is employed.

  In another aspect of the vehicle control apparatus according to the present invention, the detection means includes an imaging means capable of imaging the detection range, and the first determination means is an image obtained via the imaging means. It is determined whether or not the detected object is the target object based on a comparison between an index value that defines the presence or absence of a three-dimensional object and a second threshold value.

  According to this aspect, the detection means includes an image sensor having various aspects such as monaural (monocular) or stereo (compound eye), or an imaging device such as a video camera. Alternatively, the image forming apparatus includes a device capable of detecting the number of edges from the captured image by various known edge detection processes.

  On the other hand, the first discrimination means defines the presence or absence of a three-dimensional object in the captured image, for example, the number of edges described above (remarkably, for example, in the case of a monaural image) or the number of corresponding points between a plurality of images. Whether or not the detected object is a target is determined based on a comparison between various index values such as (for example, in the case of a stereo image) and the second threshold value. Therefore, according to this aspect, the object can be detected quickly and accurately, and the effect of improving the safety related to the control of the safety system according to the operation standard is remarkably exhibited.

  In another aspect of the vehicle control apparatus according to the present invention, the vehicle further includes position information acquisition means capable of acquiring a predetermined type of position information relating to the travel position of the vehicle, wherein the first and first At least one of the two specifying means specifies at least one of the first and second gradients corresponding to the at least one based on the acquired position information.

  According to this aspect, the vehicle is provided with position information acquisition means that can take an aspect such as a car navigation device or a positioning system using GPS (Global Positioning System), for example, a coordinate position on an appropriate map, or A predetermined type of position information is acquired as a concept including information that can specify the travel position of the vehicle, such as absolute latitude, absolute longitude, or absolute altitude.

  Here, at least one of the first and second specifying means specifies the corresponding gradient based on the acquired position information. Therefore, according to this aspect, at least one of the first and second gradients, preferably both, can be specified with relatively high accuracy, and the change of the operation reference according to the change in the gradient of the road surface can be made more finely. Can be performed. When such a car navigation device or the like is mounted on a vehicle, it is possible to estimate a near-future travel route if a travel route is set in advance or in view of a travel history, surrounding road environment, and the like. In some cases, a relatively large amount of the second gradient that can be used for comparison with the first gradient in the near future can be stored. In such a case, when the stored second gradient is actually used for comparison with the first gradient, the process can be executed smoothly, which is preferable.

  Such an operation and other advantages of the present invention will become apparent from the embodiments described below.

<Embodiment of the Invention>
Hereinafter, various preferred embodiments of the present invention will be described with reference to the drawings as appropriate.

<First Embodiment>
<Configuration of Embodiment>
First, the configuration of the vehicle 10 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram conceptually showing a configuration of a portion of the vehicle 10 related to the vehicle control device according to the present invention.

  In FIG. 1, a vehicle 10 includes an ECU 100, a navigation device 200, a forward millimeter wave radar 300, a vehicle speed sensor 400, and a safety system 500.

  The ECU 100 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like (not shown) and can control the operation of each element of FIG. 1 including an engine (not shown). 1 is an example of a “vehicle control device” according to the present invention configured. The ECU 100 is configured to be able to execute a collision flag setting process described later according to a control program stored in the ROM.

  The navigation device 200 is displayed on various display means such as a liquid crystal display panel installed on the front console panel of the vehicle 10 based on map data stored in an appropriate storage means such as an HDD (Hard Disk Drive). It is an example of a “position information acquisition unit” according to the present invention configured to be able to display information on an absolute position obtained via various positioning systems such as GPS on a map screen. The navigation device 200 is electrically connected to the ECU 100 and is data relating to the road on which the vehicle 10 is traveling, more specifically, data relating to the gradient of the road surface at the traveling position of the vehicle 10 (hereinafter referred to as “gradient data” as appropriate). Is configured to be grasped by the ECU 100 continuously or at a constant or indefinite period as long as the positioning system is in operation, regardless of whether the map screen is displayed on the display means. Yes.

  The forward millimeter wave radar 300 is capable of emitting a millimeter wave for object detection (that is, an example of “radio wave” according to the present invention) to the front area of the vehicle 10 and is an outgoing wave reflected from an object in the front area. It is an example of the “detection means” according to the present invention configured to be able to receive a reflected wave. The forward millimeter wave radar 300 is electrically connected to the ECU 100, and the operation state thereof is controlled by the ECU 100 to the upper level. The forward millimeter wave radar 300 further determines the position of the obstacle (that is, the distance from the vehicle 10) and the relative speed between the obstacle and the vehicle 10 based on the propagation time of the emitted millimeter wave and the frequency difference caused by the Doppler effect. Etc. can be detected.

  The vehicle speed sensor 400 is a sensor configured to be able to detect the vehicle speed Vv that is the speed of the vehicle 10. The vehicle speed sensor 400 is electrically connected to the ECU 100, and the detected vehicle speed Vv is grasped by the ECU 100 constantly or at a constant or indefinite period.

  The safety system 500 is an example of a “safety system” according to the present invention that can improve the collision safety of the vehicle 10, and includes a braking device 510, a seat belt control device 520, and an alarm device 530. It should be noted that the elements constituting the safety system 500 may include those used for normal traveling control in the vehicle 10 such as the braking device 510, for example.

  The braking device 510 is an example of a “braking unit” according to the present invention configured to be able to apply a braking force to a wheel (not shown) of the vehicle 10. The braking device 510 applies a braking force according to the hydraulic pressure of the hydraulic fluid transmitted to a wheel cylinder or the like provided in each wheel via transmission means such as a brake actuator in accordance with the operation of the brake pedal by the driver. Is a disc brake device that is configured to be possible. In addition, the aspect of the braking device 510 is not limited to this. Since the brake actuator described above is under the control of the ECU 100, a braking force is automatically applied to each wheel independently of the braking operation by the driver (such as stepping on the brake pedal described above). It is the structure to obtain.

  The seat belt control device 520 is a protection means for protecting the body of an occupant of the vehicle 10 including the driver. The seat belt control device 520 is configured to include a belt unit that physically protects an occupant, and a control system that controls the pressure applied to the belt, and the control system is controlled by the ECU 100 in a higher level. It has a configuration. Therefore, the pressure applied when the belt portion protects the occupant is controlled by the ECU 100.

  The alarm device 530 is an alarm device disposed on, for example, the front console panel of the vehicle 10. The alarm device 530 is electrically connected to the ECU 100, and when activated by the ECU 100, an alarm or warning sound of a predetermined volume flows in the vehicle interior.

<Operation of Embodiment>
<Overview of safety system operation>
The braking device 510, the seat belt control device 520, and the alarm device 530 that constitute the safety system 500 are provided in the ECU 100 when an obstacle (that is, an example of the “object” according to the present invention) exists in the front area of the vehicle 10. Thus, the vehicle 10 is controlled in a coordinated manner to improve the collision safety of the vehicle 10. The respective operation standards are different from each other, and the braking device 510 applies a braking force to the wheels, for example, 0.6 seconds before the collision between the vehicle 10 and the obstacle occurs, and the seat belt control device 520. The warning device 530 further provides a predetermined alarm to the driver 2 seconds before the collision occurs so that the seat belt pressure increases 0.8 seconds before the collision occurs. Each is controlled.

  Whether each element of the safety system 500 can be operated is controlled by a collision flag set for each element. When the collision flag is turned on, each element constituting the safety system 500 is operated. Therefore, the state of the collision flag is an element that determines the operating state of the safety system 500. That is, the setting state of the collision flag is an example of the “operation standard” according to the present invention. The state of the collision flag is controlled by a collision flag setting process executed by the ECU 100.

<Details of collision flag setting processing>
Here, the details of the collision flag setting process will be described with reference to FIG. FIG. 2 is a flowchart of the collision flag setting process.

  In FIG. 2, the ECU 100 detects the intensity of a millimeter wave (that is, a reflected wave) reflected from an object existing in the front area of the vehicle 10 from the front millimeter wave radar 300 (hereinafter, referred to as “reflected wave intensity” as appropriate) Pr. Is acquired (step A10). At the stage where the reflected wave is acquired, the presence of an object in the front area of the vehicle 10 is detected.

  Next, the ECU 100 determines that the detected object is an obstacle based on a comparison between the acquired reflected wave intensity Pr and a preset threshold value S (that is, an example of the “first threshold value” according to the present invention). It is determined whether or not it is an object (step A11). Here, the threshold value S is such that the longer the distance Df is, that is, the farther it is from the vehicle 10 in the coordinate system in which the vertical axis and the horizontal axis represent the reflected wave intensity Pr and the distance Df from the vehicle 10 in the front area, respectively. , Expressed as a decreasing curve. The ECU 100 compares the acquired reflected wave intensity Pr with the threshold value S at the distance corresponding to the reflected intensity Pr in the process according to step A11, and when the acquired reflected wave intensity Pr is equal to or greater than the threshold value S. The object corresponding to the reflected wave intensity Pr is determined as an obstacle.

  When there is no obstacle (step A11: NO), the ECU 100 returns the process to step A10 and repeats a series of processes. When there is an obstacle (step A11: YES), the ECU 100 detects the obstacle. Distance L, vehicle speed Vv of vehicle 10, and relative speed Vr of vehicle 10 with respect to the detected obstacle are acquired (step A12). The vehicle speed Vv is acquired based on the output of the vehicle speed sensor 400, and the distance L and the relative speed Vr are the frequency differences caused by the millimeter wave propagation time and the Doppler effect when the object is detected by the forward millimeter wave radar 300. Is calculated by the forward millimeter wave radar 300 based on the above and acquired by the ECU 100.

  Next, the ECU 100 determines whether or not the absolute value of the difference between the vehicle speed Vv and the relative speed Vrj is less than the reference value C1 (step A13). Here, the reference value C1 is set to zero or a value small enough to be regarded as zero, and the process according to step A13 is a process for determining whether or not the obstacle is a stationary object. Yes. More specifically, if the obstacle is a stationary object, the relative speed Vrj with respect to the vehicle 10 is substantially the same as the vehicle speed Vv, the absolute value is relatively small, and the determination processing according to step A13 is “ YES ”. On the other hand, if the obstacle is a forward vehicle or the like, the relative speed Vrj tends to be a sufficiently small value with respect to the vehicle speed Vv, although there is a difference in the vehicle speed, and the absolute value becomes relatively large, and the determination related to step A13. The process is “NO”. If the obstacle is not a stationary object (step A13: NO), the process proceeds to step A18. The process related to step A18 will be described later.

  On the other hand, when the obstacle is a stationary object (step A13: YES), the ECU 100 further refers to the gradient data supplied from the navigation device 200, and the vehicle gradient, which is the gradient value of the road surface at the current position of the vehicle 10. The value G0 is acquired (step A14), and the front gradient value Gf, which is the gradient value of the road surface at the front position of the vehicle 10, is acquired (step A15). Here, the distance from the vehicle 10 at the position where the forward gradient value is defined is not necessarily within the detection range of the forward millimeter wave radar 300. In addition, the distance may be a fixed value or a variable value, and if it is variable, the distance is set to be as close as possible to the position of the object determined as an obstacle. May be. Furthermore, according to the navigation device 200, the distance that defines the forward gradient value can be selected relatively freely, so that an optimum distance may be set for the position of the obstacle each time.

  When the own vehicle gradient value G0 and the forward gradient value Gf are acquired, the ECU 100 calculates the absolute value of the difference between them and determines whether or not the calculated absolute value is equal to or greater than the reference value C2 (step). A16). Here, the reference value C2 is set as a value that prescribes the degree of change in the slope of the road surface that can affect the erroneous detection of an obstacle, for example, experimentally, empirically, theoretically, or based on simulation. It is an example of the “predetermined value” according to the present invention.

  When the absolute value of the difference between the gradient values is less than the reference value C2 (step A16: NO), the ECU 100 proceeds to step A18. That is, qualitatively, in this case, even if the detected obstacle is a stationary object, it is considered that the change in the gradient of the road surface does not cause erroneous detection. On the other hand, when the absolute value of the difference between the gradient values is greater than or equal to the reference value C2 (step A16: YES), the ECU 100 proceeds to step A17.

  In the processing according to step A17 and step A18, a threshold value Ct of the collision prediction time TTC is set. Here, the predicted collision time TTC is a value obtained by dividing the distance L to the obstacle by the relative speed Vr of the vehicle 10 with respect to the obstacle, and collides with the obstacle when the current relative speed is maintained. It is time until. The threshold value Ct of the collision prediction time TTC is a threshold value that defines the timing at which the collision flag should be turned on (as described above, the timing is substantially the same as the timing at which the safety system operates).

  In the process according to step A18, that is, under the condition that it is estimated that no erroneous detection of an obstacle has occurred, the ECU 100 sets the threshold value Ct to Ct1. Here, Ct1 is stored in advance in the ROM as a fixed value individually for each element constituting the safety system 500. On the other hand, in the process according to step A17, that is, under the condition that it is estimated that the possibility of erroneous detection of an obstacle is relatively high, the ECU 100 sets the threshold Ct to Ct2 (Ct2 <Ct1). Set. Here, Ct2 is stored in advance as a fixed value for each element constituting the safety system 500 in the ROM in the same manner as Ct1.

  When the threshold value Ct of the collision prediction time TTC is set, the ECU 100 determines whether or not the collision prediction time TTC is less than the threshold value Ct (step A19). When the collision prediction time TTC is less than the threshold Ct (step A19: YES), the ECU 100 controls the collision flag to be in an ON state (step A20), and when the collision prediction time TTC is equal to or greater than the threshold Ct (step A19: NO). The ECU 100 controls the collision flag to be in an OFF state (step A21). When the process according to step A20 or step A21 is executed, the ECU 100 returns the process to step A10 and repeats a series of processes.

  According to the collision flag setting process according to the present embodiment, the obstacle defined as the object having the millimeter wave reflection intensity Pr equal to or higher than the threshold value S is based on the relative speed between the vehicle 10 and the obstacle. Whether or not the obstacle is a stationary object is determined, and when it is determined that the obstacle is a stationary object, the obstacle is further based on the absolute value of the difference between the gradient of the current position of the vehicle 10 and the gradient of the front position. Thus, it is determined whether or not the road surface gradient change is large. If the gradient change is large, there is no need to detect it as an obstacle, for example, various patterns such as the road surface itself, pedestrian crossings or road signs, or various structures such as overbridges, guardrails, installation signs, bulletin boards or tunnels. In consideration of the possibility that a stationary object such as an object is erroneously detected as an obstacle, the threshold Ct of the collision prediction time TTC is compared with the case where the obstacle is not a stationary object or the gradient change is relatively small. Is set to a small value. Since the collision flag is set to the ON state when the collision prediction time TTC is less than the threshold value Ct, the safety system 500 becomes difficult to operate when the change in the road gradient is large. That is, a decrease in safety due to a malfunction of the safety system 500 is suppressed.

  In the collision flag setting process described above, the threshold Ct is described as if it is a value shared among the components of the safety system 500 in the processes in Step A17 and Step A18. In reality, the threshold value Ct is set individually for each of the braking device 510, the seat belt control device 520, and the alarm device 530 constituting the safety system 500.

  In addition, the threshold values Ct corresponding to these elements may of course be changed completely independently, and for example, a magnitude relationship or a more detailed numerical relationship is maintained so that the mutual relationship before and after the change is maintained. It may be set so that.

  In this embodiment, as an example of the “operation standard” according to the present invention, the threshold value Ct of the predicted collision time TTC that defines the operation timing of the safety system 500 is changed according to the change in the road surface gradient. Examples of the reference are not limited to this, and various modes can be adopted. For example, when the collision flag is in the ON state, the maximum value of the braking force forcibly applied via the braking device 510 is relatively decreased, or the force is changed forcibly via the seat belt control device 520. The operating scale of the safety system 500 may be changed by relatively reducing the pressure applied to the seat belt, or by relatively reducing the volume of the alarm related to the alarm device 530.

Second Embodiment
<Configuration of Embodiment>
The means for detecting the object is not limited to the forward millimeter wave radar 300 in the first embodiment. Here, the second embodiment of the present invention will be described. First, the configuration of the vehicle 11 according to the second embodiment will be described with reference to FIG. FIG. 3 is a block diagram conceptually showing the configuration of a portion of the vehicle 11 related to the vehicle control device according to the present invention. In the figure, the same reference numerals are given to the same portions as those in FIG. 1, and the description thereof will be omitted as appropriate.

  In FIG. 3, the vehicle 11 does not have the front millimeter wave radar 300 according to the first embodiment, and is a monocular image sensor 600 (that is, “imaging unit” according to the present invention) as another example of the “detection unit” in the present invention. Is different from the vehicle 10 according to the first embodiment.

  The monocular image sensor 600 detects a monocular imaging unit that images the front region of the vehicle 11, an image processing unit that generates an image of the captured front region, and the number of edges (that is, the number of edges) in the generated image. And an edge detection unit (both not shown) for detecting an object in the front area of the vehicle 10. The monocular image sensor 600 is electrically connected to the ECU 100, and the detected number of edges is grasped by the ECU 100 constantly or at a constant or indefinite period. Note that, as a method of edge detection in the monocular image sensor 600, a method of obtaining a spatial density change of an image using a first derivative is adopted, but various known methods can be used for edge detection. Is possible. Note that the number of edges in the captured image may be executed by the ECU 100 or may be determined by another image processing device.

<Operation of Embodiment>
Next, a collision flag setting process according to the second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a flowchart of the collision flag setting process. In the figure, the same reference numerals are given to the same portions as those in FIG. 2, and the description thereof will be omitted as appropriate.

  In FIG. 4, the ECU 100 acquires the number of edges EG in the image of the front area of the vehicle 10 captured by the monocular image sensor 600 (step B10).

  Next, the ECU 100 determines that the imaged object is an obstacle based on a comparison between the acquired number of edges EG and a preset threshold value S (that is, an example of the “second threshold value” according to the present invention). Is determined (step A11). Here, the threshold value S is stored in the ROM as a fixed value adapted in advance. In the process according to step A11, the ECU 100 compares the acquired edge number EG with the threshold value S. If the acquired edge number EG is equal to or greater than the threshold value S, the ECU 100 It is determined that it is a thing.

  Note that the monocular image sensor 600 needs to calculate the relative speed of the vehicle with respect to the object and the distance to the object based on a plurality of images. Therefore, in the process according to step A12, the imaging and edge analysis processes are originally repeated a plurality of times. However, in FIG. 4, that point is omitted for the purpose of preventing the drawing from becoming complicated. Further, the processing related to step A13 and subsequent steps is basically the same as that in the first embodiment.

  As described above, according to the obstacle determination process according to the second embodiment, the monocular image sensor 600 is provided instead of the millimeter wave radar 300 of the first embodiment, and the obstacle is detected. On the other hand, since the obstacle detection accuracy by the monocular image sensor 600 is also affected by the change in the gradient of the road surface, the threshold Ct of the collision prediction time TTC is changed as in the first embodiment. With the change of the threshold value Ct, the safety system 500 becomes difficult to operate, and a decrease in safety due to a malfunction of the safety system 500 is suppressed.

  In the first and second embodiments described above, the degree of change in the road surface gradient is adopted as an example of the “relative relationship” according to the present invention, and the absolute difference between the vehicle gradient value G0 and the forward gradient value Gf is adopted. Although the value is used for comparison with the reference value C2 as a value, the index value that defines the relative relationship is not limited to this. In calculating the absolute value of the difference, the vehicle gradient value G0 is acquired based on position information obtained by the navigation device 200. For example, when the vehicle is provided with a pendulum type acceleration sensor, for example. The vehicle gradient value G0 may be acquired based on, for example, a comparison between an acceleration value detected by the pendulum acceleration sensor and an acceleration value obtained as a time differential value of the vehicle speed Vv obtained from the vehicle speed sensor 400. .

  In the various embodiments described above, each of the detection means according to the present invention includes a millimeter wave radar or a monocular image sensor, but of course, the detection means according to the present invention may be physical, mechanical, You may be comprised from several means from which mechanical or electrical structure differs. More specifically, for example, the vehicle may include both radio wave positioning means such as a millimeter wave radar and imaging means such as a monocular image sensor. For example, since millimeter wave radar detects an object as a reflected wave to the last, it is difficult to detect the width and three-dimensional shape of the object, but physical quantities such as distance and speed are accurately detected. On the other hand, a monocular image sensor may be inferior to millimeter waves in detection accuracy of physical quantities such as distance and speed, but can detect the width and shape of an object relatively accurately. Therefore, by combining these, it is possible to effectively suppress the occurrence of erroneous detection of an obstacle itself.

  The present invention is not limited to the above-described embodiments, and can be changed as appropriate without departing from the spirit or concept of the invention that can be read from the claims and the entire specification. Is also included in the technical scope of the present invention.

1 is a block diagram conceptually showing a configuration of a portion related to a vehicle control device according to the present invention in a vehicle according to a first embodiment of the present invention. It is a flowchart of the collision flag setting process in the vehicle of FIG. It is a block diagram which expresses notionally the composition of the portion related to the control device of the vehicle concerning the present invention in the vehicle concerning a 2nd embodiment of the present invention. It is a flowchart of the collision flag setting process which concerns on 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Vehicle, 100 ... ECU, 200 ... Navigation device, 300 ... Forward millimeter wave radar, 400 ... Vehicle speed sensor, 500 ... Safety system, 510 ... Braking device, 520 ... Seat belt control device, 530 ... Alarm device, 600 ... Monocular Image sensor.

Claims (8)

A vehicle control apparatus for controlling a vehicle including a detection unit capable of detecting an object in a front detection range, and a predetermined type of safety system capable of improving collision safety during operation,
First determining means for determining whether or not the detected object is a target;
An operation control means for operating the safety system in accordance with a predetermined type of operation standard when it is determined that the detected object is the object;
First specifying means for specifying a first gradient that represents a gradient at the traveling position of the vehicle;
Second specifying means for specifying a second gradient representing a gradient at a forward position of the vehicle;
A vehicle control apparatus comprising: a changing unit that changes the operation reference according to the relative relationship between the specified first and second gradients. The said change means changes the said action | operation standard so that the said safety system becomes difficult to operate | move, when the degree of deviation of the said 1st gradient and the said 2nd gradient is large. Vehicle control device. The said change means changes the said action | operation reference | standard when the absolute value of the difference of the said 1st gradient and the said 2nd gradient which prescribes | regulates the degree of said deviation is more than predetermined value. The vehicle control device described in 1. The safety system includes braking means capable of applying a braking force to the vehicle,
The changing means includes (i) the timing at which the braking force is applied is delayed, (ii) the braking force to be applied is reduced, or (iii) the braking force is increased at the start of the application. The vehicle control device according to claim 2 or 3, wherein the operation reference is changed so that the rate decreases. Further comprising second determination means for determining whether or not the detected object is a stationary object;
The vehicle according to any one of claims 1 to 4, wherein the change unit changes the operation reference when it is determined that the detected object is the stationary object. Control device. The detection means includes a radar capable of detecting the object by emitting a radio wave having a predetermined wavelength in the detection range and receiving a reflected wave formed by reflecting the emitted radio wave on the object,
The first determination unit determines whether or not the detected object is the target object based on a comparison between an index value corresponding to the intensity of the received reflected wave and a first threshold value. The vehicle control device according to any one of claims 1 to 5, wherein The detection means includes an imaging means capable of imaging the detection range,
In the first determination unit, the detected object is the target object based on a comparison between an index value that defines the presence or absence of a three-dimensional object in the image obtained through the imaging unit and a second threshold value. It is discriminate | determined whether it is. The vehicle control apparatus as described in any one of Claim 1 to 6 characterized by the above-mentioned. The vehicle further includes position information acquisition means capable of acquiring a predetermined type of position information related to the traveling position of the vehicle,
At least one of the first and second specifying means specifies at least one of the first and second gradients corresponding to the at least one based on the acquired position information. Item 8. The vehicle control device according to any one of Items 1 to 7.

Images