Vehicle control device

Abstract

To reduce a possibility that unnecessary vehicle control is executed due to the false recognition of a stationary object, in position estimation processing (dead reckoning) of estimating the position, with respect to a vehicle, of an object which an object sensor has no longer detected.SOLUTION: When an object which an object sensor detected is no longer detected, a control unit executes position estimation processing of estimating an object position at and after a time point when the object is no longer detected by the object sensor. While the control unit is executing the position estimation processing at an OFF time point when the ignition of a vehicle is changed from an ON state to an OFF state, if the object is a stationary object, the control unit stores the object position of the stationary object at the OFF time point and the current position of the vehicle at the OFF time point. At an ON time point when the ignition is changed from the OFF state to the ON state, in a case where it is determined that the vehicle is moved within a period from the OFF time point to the ON time point, the control unit does not estimate the object position of the stationary object by the position estimation processing.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a vehicle control device that executes a position estimation process (dead reckoning) for estimating the position of an object relative to the vehicle when the object sensor no longer detects the object. [Background technology]

[0002] Conventionally, there have been known vehicle control devices that perform dead reckoning to estimate the position (object position) of an "object that is no longer detected by an object sensor (radar, camera, etc.)" relative to the vehicle. For example, a vehicle control device described in Patent Document 1 (hereinafter referred to as the "conventional device") performs dead reckoning to estimate the position of other vehicles based on the detection information that was acquired immediately before the detection information could no longer be received and data acquired from various sensors of the vehicle when it is unable to acquire detection information of other vehicles. The conventional device then controls the vehicle based on the positions of other vehicles. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2013 / 153660 Summary of the Invention

[0004] The inventors are considering the following vehicle control device (hereinafter referred to as the "considered device") in order to recognize stationary objects at the on-point using "the result of dead reckoning at the off-point". The ON time is when the vehicle ignition changes from the OFF state to the ON state, i.e., when the vehicle ignition key switch changes from the OFF position to the ON position. The OFF time is when the vehicle ignition changes from the ON state to the OFF state, i.e., when the vehicle ignition key switch changes from the ON position to the OFF position.

[0005] The study device stores the result of the dead reckoning (the position of the stationary object relative to the vehicle) that was executed when the device was turned off in a non-volatile memory (e.g., EEPROM). When the study device is turned on, the study device estimates the object position of the stationary object based on the result of the dead reckoning that was stored in the non-volatile memory.

[0006] According to the study device, the object position of a stationary object is estimated when the vehicle ignition is turned on under the assumption that the vehicle and the stationary object do not move during the period when the vehicle ignition is turned off. As a result, even if the stationary object is not detected by the object sensor when the vehicle ignition is turned on, the study device can estimate the object position of the stationary object.

[0007] However, during the off period from the off time to the on time, the vehicle may be moved by a tow truck or the like. In such a case, if the object position of the stationary object is estimated at the on time based on the dead reckoning result stored by the investigation device, it may be erroneously recognized that a stationary object exists around the vehicle after the vehicle has moved, even though the stationary object does not exist around the vehicle. Then, unnecessary vehicle control may be executed based on the object position of the erroneously recognized stationary object.

[0008] The present invention has been made to address the above-mentioned problems. That is, one of the objects of the present invention is to provide a vehicle control device that prevents a stationary object that does not exist around the vehicle from being erroneously recognized when the vehicle is moving during an off period, and reduces the possibility of unnecessary vehicle control being executed.

[0009] The vehicle control device of the present invention (hereinafter also referred to as the "device of the present invention") is an object sensor (21, 22) for detecting an object located within a predetermined detectable area (DA) around a vehicle (VA); a state value sensor (23, 24, 25) configured to detect a driving state value related to a driving state of the vehicle; a control unit (20, 30, 40) configured to perform a predetermined vehicle control for the object (step 640) when an index value acquired based on an object position, which is a position of the object detected by the object sensor relative to the vehicle, satisfies a predetermined control condition (step 635 "Yes"); Equipped with.

[0010] The control unit If the object that was detected by the object sensor is no longer detected because it is located outside the detectable area (step 525 "Yes"), a position estimation process is executed to estimate the object position of the object that is no longer detected by the object sensor based on the traveling state value and the object position when it was detected by the object sensor (step 545); When the position estimation process is being performed (step 710 “Yes”) at the off time when the ignition of the vehicle changes from an on state to an off state (step 705 “Yes”), if the object whose position was estimated by the position estimation process is a stationary object (step 715 “Yes”), off position identification information capable of identifying the object position of the stationary object at the off time and the position of the vehicle at the off time is stored (step 720, step 730); At the on-time when the ignition changes from the off state to the on state (step 845 “Yes”), if it is determined that the vehicle has not moved during the period from the off-time to the on-time based on the on-location identification information and the off-location identification information that can identify the location of the vehicle at the on-time (step 830 “Yes”), the object location of the stationary object is estimated by the location estimation process (step 835); When it is determined that the vehicle has moved during the period based on the on-location identification information and the off-location identification information at the on-time point (step 830 "No"), the object position of the stationary object is not estimated by the position estimation process (step 815); It is structured as follows.

[0011] If the vehicle moves during the off period from the off time to the on time, the current position of the vehicle at the on time is likely not within a predetermined range from the current position of the vehicle at the off time. In this case, the positional relationship between the stationary object and the vehicle has changed, so the stationary object is likely not present around the vehicle. Therefore, according to the device of the present invention, even if the object position of the stationary object is estimated by the position estimation process at the off time, the position of the stationary object is not estimated by the position estimation process at the on time. As a result, if the vehicle moves during the off period, the object position of the stationary object that is not present around the vehicle is not estimated, so that it is possible to prevent the stationary object that is not present around the vehicle from being erroneously recognized. And it is possible to reduce the possibility that unnecessary vehicle control is executed due to the erroneous recognition of the stationary object.

[0012] In the above description, in order to facilitate understanding of the invention, the names and / or symbols used in the embodiments described below are enclosed in parentheses with respect to the configuration of the invention corresponding to the embodiments. However, each component of the invention is not limited to the embodiments defined by the names and / or symbols. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic system configuration diagram of a vehicle control device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an explanatory diagram of the detectable and undetectable areas of the millimeter wave radar and the front camera shown in FIG. [Diagram 3] FIG. 3 is an explanatory diagram of the dead reckoning performed by the vehicle control device according to the embodiment of the present invention. [Figure 4] FIG. 4 is an explanatory diagram illustrating an outline of the operation of the vehicle control device according to the embodiment of the present invention. [Diagram 5] FIG. 5 is a flowchart showing an object recognition routine executed by the CPU of the driving assistance ECU shown in FIG. [Figure 6] FIG. 6 is a flowchart showing a vehicle control routine executed by the CPU of the driving assistance ECU shown in FIG. [Figure 7] FIG. 7 is a flowchart showing an off-time storage routine executed by the CPU of the driving assistance ECU shown in FIG. [Figure 8] FIG. 8 is a flowchart showing an on-time determination routine executed by the CPU of the driving assistance ECU shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] <Configuration> As shown in FIG. 1, a vehicle control device (hereinafter, referred to as "the control device") 10 according to an embodiment of the present invention is mounted on a vehicle VA.

[0015] The control device 10 includes a driving assistance ECU 20, an engine ECU 30, and a brake ECU 40. Hereinafter, the driving assistance ECU 20 will be referred to as "DSECU 20."

[0016] These ECUs are control units (Electronic Control Units) that include a microcomputer as a main component, and are also called "controllers" or "control units." The microcomputer includes a CPU, ROM, RAM, a writable non-volatile memory (EEPROM in this example), and an interface (I / F), etc. These ECUs are connected via a Controller Area Network (CAN) so that they can send and receive information to each other. The CPU realizes various functions by executing instructions (programs, routines) stored in the ROM. Some or all of these ECUs may be integrated into a single ECU.

[0017] Furthermore, the control device 10 includes a millimeter wave radar 21, a front camera 22, a wheel speed sensor 23, an acceleration sensor 24, a steering angle sensor 25, and a GNSS (Global Navigation Satellite System) receiver 26. These are connected to the DSECU 20 so as to be able to exchange data.

[0018] The millimeter-wave radar 21 is a well-known sensor for detecting an object by transmitting millimeter waves ahead of the vehicle VA and receiving millimeter waves reflected by the object (reflected waves). Based on the received reflected waves, the millimeter-wave radar 21 calculates the distance to the object (object distance) L, the relative speed (object relative speed) Vr of the object with respect to the vehicle VA, and the direction of the object. Then, the millimeter-wave radar 21 transmits "radar object information including the object distance L, object relative speed Vr, and object direction" to the DSECU 20 every time a predetermined time elapses.

[0019] As shown in FIG. 2, the millimeter wave radar 21 is disposed in the front end center of the front grill FG of the vehicle VA. The millimeter wave radar 21 transmits millimeter waves that have a predetermined angle θd in the left and right directions from a "central axis C1 extending from the front end center in the longitudinal direction Dx of the vehicle VA" and propagate to an area from the front end center to a maximum detection distance Lmax. Therefore, the millimeter wave radar 21 can detect objects present in the above area. However, the millimeter wave radar 21 cannot detect objects present in a non-detectable area NDA that is less than the minimum detection distance Lmin from the front end center. The millimeter wave radar 21 detects objects present in a detectable area DA that is equal to or greater than the minimum detection distance Lmin from the front end center and less than the maximum detection distance Lmax.

[0020] 2, the direction indicated by the symbol Dx is the front-rear direction of the vehicle VA as described above and is referred to as the "front-rear direction Dx." The direction indicated by the symbol Dy is the width direction of the vehicle VA and is referred to as the "vehicle width direction Dy."

[0021] The front camera 22 is disposed at the center upper part of the front window FW inside the vehicle VA, and captures an image of the area in front of the vehicle VA (hereinafter, also referred to as a "front image"). The front camera 22 acquires the distance to an object and the direction of the object based on the front image. The front camera 22 transmits camera object information including these to the DSECU 20 every time a predetermined time elapses. 2, the front camera 22 cannot detect an object that exists in a non-detectable area NDA' that is less than the minimum detection distance Lmin' from the front camera 22. The front camera 22 detects an object that exists in a detectable area DA' that is equal to or greater than the minimum detection distance Lmin' from the front camera 22 and less than the maximum detection distance Lmax'. In this example, as shown in Fig. 2, the distance Lmin of the undetectable area NDA from the front end of the vehicle VA is shorter than the distance of the undetectable area NDA' from the front end of the vehicle VA. Therefore, if an object is located in an area shorter than the minimum detection distance Lmin, neither the millimeter wave radar 21 nor the front camera 22 can detect the object, and therefore the DSECU 20 cannot recognize the object.

[0022] The wheel speed sensor 23 is provided for each wheel of the vehicle VA. Each wheel speed sensor 23 generates one wheel pulse signal each time the corresponding wheel rotates a predetermined angle. The DSECU 20 counts the number of pulses per unit time of the wheel pulse signal received from each wheel speed sensor 23, and obtains the rotation speed of each wheel based on the number of pulses. Then, the DSECU 20 obtains a vehicle speed Vs indicating the speed of the vehicle VA based on the wheel speed of each wheel. As an example, the DSECU 20 obtains the average value of the wheel speeds of the four wheels as the vehicle speed Vs.

[0023] The acceleration sensor 24 measures the acceleration Gx of the vehicle VA in the longitudinal direction Dx and the acceleration Gy of the vehicle VA in the vehicle width direction Dy, and generates detection signals representing the acceleration Gx and the acceleration Gy. The DSECU 10 identifies the acceleration Gx and the acceleration Gy of the vehicle VA by receiving the detection signal from the acceleration sensor 24.

[0024] The steering angle sensor 25 detects a steering angle θ, which is a rotation angle of a steering wheel (not shown) of the vehicle VA with respect to a neutral position, and generates a detection signal representing the steering angle θ. The DSECU 10 identifies the steering angle θ by receiving the detection signal from the steering angle sensor 25.

[0025] The wheel speed sensor 23, the acceleration sensor 24, and the steering angle sensor 25 are sensors for detecting driving state values ​​related to the driving state of the vehicle VA, and may be referred to as "state value sensors."

[0026] The GNSS receiver 26 receives "signals from artificial satellites (GNSS signals)" and identifies the current position (latitude, longitude) of the vehicle VA based on the GNSS signals. The GNSS receiver 26 transmits a signal indicating the current position of the vehicle VA to the DSECU 10 every time a predetermined time elapses.

[0027] The engine ECU 30 is connected to an engine actuator (engine Act) 32. The engine actuator 32 includes a throttle valve actuator that changes the opening of a throttle valve of an engine (E / G) 34. The engine ECU 30 can change the torque generated by an engine (internal combustion engine) 34 by driving the engine actuator 32. The torque generated by the engine 34 is transmitted to driving wheels via a transmission (not shown). Therefore, the engine ECU 30 can control the driving force of the vehicle VA and change the acceleration Gx by controlling the engine actuator 32.

[0028] If the vehicle VA is a hybrid vehicle, the engine ECU 30 controls the driving force of the vehicle VA generated by either or both of the "engine and the electric motor" as the vehicle driving source. Furthermore, if the vehicle VA is an electric vehicle, the engine ECU 30 controls the driving force of the vehicle VA generated by the electric motor as the vehicle driving source.

[0029] The brake ECU 40 is connected to a brake actuator (Brake Act) 42. The brake actuator 42 is provided in a hydraulic circuit between a master cylinder (not shown) that pressurizes hydraulic oil by the depression force of a brake pedal (not shown) of the vehicle VA, and a friction brake mechanism 44 provided on each wheel of the vehicle VA. The friction brake mechanism 44 includes a brake disc 44a fixed to the wheel, and a brake caliper 44b fixed to the vehicle body.

[0030] The brake actuator 42 adjusts the hydraulic pressure supplied to the wheel cylinder built into the brake caliper 44b in response to a command from the brake ECU 40, and operates the wheel cylinder with the hydraulic pressure. As a result, the brake actuator 42 presses the brake pad against the brake disc 44a to generate a friction braking force. Therefore, the brake ECU 40 can control the braking force of the vehicle VA by controlling the brake actuator 42, thereby changing the acceleration Gx (negative acceleration Gx).

[0031] <Object recognition> DSECU10 identifies the position of object Ob relative to vehicle VA (hereinafter referred to as "object position P") based on radar object information and camera object information every time a predetermined time has elapsed. Since object Ob is located in detectable area DA at time ta shown in FIG. 3, millimeter wave radar 21 can detect object Ob. DSECU10 identifies object position Pta at time ta based on radar object information and camera object information. DSECU10 estimates object position P'ta+1 at time ta+1, a predetermined time after time ta.

[0032] In detail, first, the DSECU 10 obtains the position of the object Ob at the time ta+1 when it is assumed that the object Ob moves for a predetermined time along the moving direction of the object Ob at the time ta at the absolute speed Va of the object Ob at the time ta. The moving direction of the object Ob is identified based on the "history of the object position P (Pta-1, Pta-2)" and the "traveling course of the vehicle VA identified based on the vehicle speed Vs and the steering angle θ at the time ta-1 and the time ta-2". The absolute speed Va at the time ta is identified based on the object relative speed Vr at the time ta and the vehicle speed Vs at the time ta. Next, the DSECU 10 determines the position of the vehicle VA at the time ta+1 based on the acceleration Gx, the acceleration Gy, and the vehicle speed Vs at the time ta. Furthermore, the DSECU 10 determines the orientation of the vehicle VA at the time ta+1 based on the steering angle θ at the time ta. Then, the DSECU 10 estimates the object position P'ta+1 based on the position of the object Ob, the position of the vehicle VA, and the orientation of the vehicle VA at the time point ta+1.

[0033] At time ta+1, the object Ob is located in the non-detectable area NDA, so that neither the millimeter wave radar 21 nor the front camera 22 can detect the object Ob, and the DSECU 20 cannot recognize the object Ob. As a result, the DSECU 10 cannot find the object Ob within a predetermined range from the object position P'ta+1. The DSECU 10 identifies the object Ob as a lost object and estimates the object position Pta+1 at time ta+1 by executing dead reckoning (position estimation processing) to estimate the position of the object Ob relative to the vehicle VA. The dead reckoning is substantially the same as the estimation processing of the object position P'ta+1 at the above-mentioned time ta. However, in the dead reckoning, the DSECU 10 differs from the above-mentioned estimation processing in that the DSECU 10 identifies the position of the vehicle VA at time t1 based on the actual "acceleration Gx, acceleration Gy, and vehicle speed Vs of the vehicle VA" during the period from time ta to time ta+1.

[0034] At time ta+2, similarly to time ta+1, the DSECU 20 cannot recognize the object Ob. Therefore, the DSECU 10 estimates the object position Pta+2 at time ta+2 by dead reckoning.

[0035] DSECU10 continues the dead reckoning of the lost object until the object position P estimated by the dead reckoning is behind a predetermined position (e.g., the front end) of the vehicle VA. That is, DSECU10 starts the dead reckoning when a certain object Ob becomes a lost object, and ends the dead reckoning when the object position P of the lost object reaches the predetermined position of the vehicle VA.

[0036] <Vehicle Control> The DSECU 10 obtains an index value based on at least the object position P, and performs a predetermined vehicle control when the index value satisfies a predetermined control condition.

[0037] As an example, the index value is TTC (Time To Collision). TTC is a value that indicates the time it takes for an object to collide with the vehicle VA (time required for collision). The DSECU10 acquires the TTC based on the relative speed Vr and the object position P of the object.

[0038] When the TTC is equal to or less than the threshold time Tth, the DSECU 10 determines that the index value satisfies the control condition, and executes braking control as vehicle control. In this braking control, the DSECU 10 transmits a predetermined target acceleration Gxt (Gxt<0) in the forward / rearward direction Dx to the engine ECU 30 and the brake ECU 40. The engine ECU 30 and the brake ECU 40 control the engine actuator 32 and the brake actuator 42, respectively, so that the actual acceleration Gx coincides with the target acceleration Gxt.

[0039] The index value and the vehicle control are not limited to the above examples, and other examples of the index value and the vehicle control will be described later.

[0040] (Overview of operation) 4, the DSECU10 determines whether or not dead reckoning is being performed at the off time toff when an ignition key switch (not shown) of the vehicle VA is changed from the on position to the off position. If the ignition key switch is in the on position, the ignition of the vehicle VA is in the on state (i.e., the vehicle drive source is running), and if the ignition key switch is in the on position, the ignition of the vehicle VA is in the off state (i.e., the vehicle drive source is not running). When dead reckoning is being performed, the DSECU 20 determines whether the object Ob, whose object position P is estimated by dead reckoning, is a “stationary object.” In detail, the DSECU 10 acquires the moving speed of the object Ob based on the last detected object relative speed Vr and vehicle speed Vs of the object Ob, and determines that the object Ob is a stationary object if the moving speed is equal to or lower than a predetermined threshold speed. If the object Ob is a stationary object, the DSECU10 stores the object position P of the object Ob estimated by dead reckoning and the current position Pvoff of the vehicle VA in the EEPROM at the off time toff. Hereinafter, the object position P estimated by dead reckoning is referred to as the "object position Pdr." Information capable of identifying the current position Pvoff of the vehicle VA stored in the EEPROM may be referred to as the "off position identification information."

[0041] Thereafter, at the on-time ton when the ignition key switch is changed from the off position to the on position, if the object position Pdr of the stationary object is stored in the EEPROM (i.e., if the object position Pdr of the stationary object is estimated by dead reckoning at the off-time toff), the DSECU10 acquires the current position Pvon of the vehicle VA at the on-time ton. Note that information capable of identifying the current position Pvon of the vehicle VA at the on-time ton may be referred to as "on-position identifying information." Then, the DSECU10 obtains the distance Loff between this current position Pvon and the "current position Pvoff of the vehicle VA stored in the EEPROM." This distance Loff is the distance traveled by the vehicle VA during the off period when the ignition key switch was in the off position, and is referred to as the "travel distance Loff."

[0042] If the moving distance Loff is equal to or less than the threshold distance Lth (i.e., if the current position Pvon of the vehicle VA is within a predetermined range from the current position Pvoff of the vehicle VA), the DSECU10 determines that the vehicle VA has not moved during the off period. In this case, the DSECU10 continues the dead reckoning of the stationary object on the assumption that the object Ob (stationary object) is located at the object position Ptoff stored in the EEPROM.

[0043] When the driver of the vehicle VA depresses the accelerator pedal or takes his / her foot off the brake pedal after the on-time ton, causing the vehicle VA to move forward, the index value of the object Ob satisfies the control condition, and vehicle control is performed.

[0044] On the other hand, if the moving distance Loff is longer than the threshold distance Lth (i.e., if the current position Pvon of the vehicle VA is not within a predetermined range from the current position Pvoff of the vehicle VA), the DSECU10 determines that the vehicle VA has moved during the off period due to towing or the like. In this case, the DSECU10 does not perform dead reckoning. That is, the DSECU10 determines that the object Ob is not located at the object position Ptoff. Therefore, even if the driver of the vehicle VA depresses the accelerator pedal or releases his / her foot from the brake pedal after the on time ton, the index value of the object Ob does not satisfy the control condition. As a result, if the situation around the vehicle VA at the on time ton has changed from the off time toff due to the movement of the vehicle VA during the off period, the DSECU10 recognizes the object Ob based on the radar object information and camera object information after the on time ton without using the result of dead reckoning at the off time toff. Therefore, the DSECU 10 can prevent erroneous recognition of the object Ob that no longer exists at the on-time ton, and can prevent unnecessary vehicle control.

[0045] (Specific operation) <Object Recognition Routine> The CPU of the DSECU 10 (hereinafter, when the term "CPU" is used, it refers to the CPU of the DSECU 10 unless otherwise specified) executes an object recognition routine shown by the flowchart in FIG. 5 every time a predetermined time elapses.

[0046] Therefore, at a predetermined timing, the CPU starts the process from step 500 in FIG. 5, and executes steps 505 to 525 in order.

[0047] Step 505: The CPU acquires radar object information from the millimeter wave radar 21. Step 510 : The CPU acquires camera object information from the front camera 22 . Step 515: The CPU identifies the object position P based on the radar object information and the camera object information. The CPU determines the distance L to the object Ob based on the radar object information, and determines the direction of the object Ob based on the camera object information. That is, the CPU determines the position of the object Ob in the longitudinal direction Dx relative to the vehicle VA based on the radar object, and determines the position of the object Ob in the vehicle width direction Dy relative to the vehicle VA based on the camera object information. The CPU determines the object relative speed Vr based on the radar object information.

[0048] Step 520: As described above, the CPU predicts an object position P', which is the object position P of the object Ob after a predetermined time has elapsed. Step 525: The CPU determines whether there is a new missing object. In detail, if an object Ob predicted to be present at "object position P' predicted in step 520 the last time this routine was executed" is not detected within a specified range of object position P', the CPU identifies the object Ob as a new missing object.

[0049] If there is no new lost object, the CPU determines "No" in step 525 and determines whether the value of the dead reckoning flag Xdr is "1". The value of the dead reckoning flag Xdr is set to "1" when dead reckoning is performed, and is set to "0" when dead reckoning is not performed.

[0050] When the value of the dead reckoning flag Xdr is "0", the CPU makes a "No" determination in step 530, proceeds to step 595, and temporarily ends this routine.

[0051] If a new lost object is found when the CPU proceeds to step 525, the CPU determines "Yes" in step 525 and proceeds to step 535. In step 535, the CPU determines whether the value of the dead reckoning flag Xdr is "0" or not. If the value of the dead reckoning flag Xdr is "0", the CPU determines "Yes" in step 535 and executes steps 540 to 550 in sequence.

[0052] Step 540: The CPU sets the value of the dead reckoning flag Xdr to “1”. Step 545: The CPU estimates the object position Pdr of the missing object by dead reckoning. Step 550: The CPU determines whether or not the termination condition is met for all currently lost objects. The termination condition for each vanished object is a condition that is met when the object position Pdr of the vanished object is behind the front end of the vehicle VA. The CPU will no longer regard the object for which the termination condition is met as a lost object, and will not estimate the object position Pdr by dead reckoning the next time this routine is executed.

[0053] If there is a lost object for which the end condition has not been met, the CPU determines "No" in step 550, proceeds to step 595, and temporarily ends this routine.

[0054] When this routine is executed and the CPU proceeds to step 525 after the value of the dead reckoning flag Xdr is set to "1" in step 540, if there is no new lost object, the CPU determines "No" in step 525 and proceeds to step 530. Then, the CPU determines "Yes" in step 530 and proceeds to step 545 to estimate the object position Pdr of the lost object by dead reckoning. If a new missing object is present in the above case, the CPU determines "Yes" in step 525, proceeds to step 545, and estimates the object position Pdr of the missing object by dead reckoning.

[0055] If the termination condition is satisfied for all lost objects when the CPU proceeds to step 550, the CPU determines "Yes" in step 550 and proceeds to step 555. In step 555, the CPU sets the value of the dead reckoning flag Xdr to "0." After that, the CPU proceeds to step 595 and temporarily ends this routine.

[0056] <Vehicle control routine> The CPU executes a vehicle control routine shown in the flowchart of FIG. 6 every time a predetermined time elapses.

[0057] Therefore, at a predetermined timing, the CPU starts the process from step 600 in FIG. 6, and executes steps 605 and 610 in that order.

[0058] Step 605: The CPU obtains the object position P identified in the previously executed object recognition routine. Step 610: The CPU determines whether the value of the dead reckoning flag Xdr is "1" or not.

[0059] If the value of the dead reckoning flag Xdr is "0", the CPU determines "No" in step 610 and executes steps 615 to 625 in order. Step 615: The CPU estimates the moving direction of the object Ob based on a predetermined number of object position histories of the object Ob. Step 620: The CPU estimates a predicted movement path of the vehicle VA based on the steering angle θ and the vehicle speed Vs. Step 625: The CPU determines whether or not there is an obstacle that may collide with the vehicle VA, based on the moving direction of the object Ob and the predicted moving path of the vehicle VA.

[0060] If no obstacle is present, the CPU makes a "No" determination in step 625, proceeds to step 695, and temporarily ends this routine. On the other hand, if an obstacle is present, the CPU determines "Yes" in step 625 and executes steps 630 and 635 in this order.

[0061] Step 630: The CPU obtains the TTC of the obstacle. Step 635: The CPU determines whether the TTC is less than or equal to the threshold time Tth.

[0062] If TTC is greater than the threshold time Tth, the CPU determines "No" in step 635, proceeds to step 695, and ends this routine for the time being. On the other hand, if the TTC is equal to or less than the threshold time Tth, the CPU determines "Yes" in step 635 and proceeds to step 640. In step 640, the CPU transmits a predetermined target acceleration Gxt (Gxt<0) in the forward / rearward direction Dx to the engine ECU 30 and the brake ECU 40. After that, the CPU proceeds to step 695 and temporarily ends this routine.

[0063] If the value of the dead reckoning flag Xdr is "1" when the CPU proceeds to step 610, the CPU determines "Yes" in step 610 and proceeds to step 645. In step 645, the CPU obtains the object position Pdr estimated by the dead reckoning. After that, the CPU executes the processes from step 615 onward.

[0064] <Off-time memory routine> The CPU executes an off-time storage routine shown in the flowchart of FIG. 7 every time a predetermined time has elapsed.

[0065] Therefore, at a predetermined timing, the CPU starts the process from step 700 in Fig. 7 and proceeds to step 705. In step 705, the CPU determines whether the ignition key switch has been changed from the ON position to the OFF position.

[0066] If the ignition key switch has not been changed from the ON position to the OFF position, the CPU determines "No" in step 705, proceeds to step 795, and temporarily ends this routine.

[0067] On the other hand, if the ignition key switch has been changed from the ON position to the OFF position, the CPU determines "Yes" in step 705 and proceeds to step 710. In step 710, the CPU determines whether the value of the dead reckoning flag Xdr is "1".

[0068] If the value of the dead reckoning flag Xdr is "1", the CPU determines "Yes" in step 710 and proceeds to step 715. In step 715, the CPU determines whether or not a stationary object is present among the objects Ob whose object positions Pdr have been estimated by dead reckoning.

[0069] If a stationary object is present, the CPU determines "Yes" in step 715 and executes steps 720 to 730 in sequence. Step 720: The CPU stores the object position Pdr of the stationary object in the EEPROM. Step 725: The CPU obtains the current position of the vehicle VA as the off-vehicle position Pvoff. Step 730: The CPU stores the off-time vehicle position Pvoff in the EEPROM as off-time position specifying information. Thereafter, the CPU proceeds to step 795 and ends this routine.

[0070] If the value of the dead reckoning flag Xdr is "0" when the CPU proceeds to step 710, the CPU makes a "No" determination in step 710, proceeds to step 795, and temporarily ends this routine.

[0071] If no stationary object is present when the CPU proceeds to step 715, the CPU makes a "No" determination in step 715, proceeds to step 795, and temporarily ends this routine.

[0072] <On-time determination routine> The CPU executes an off-time storage routine shown in the flowchart of FIG. 8 every time a predetermined time has elapsed.

[0073] Therefore, at a predetermined timing, the CPU starts the process from step 800 in Fig. 8 and proceeds to step 805. In step 805, the CPU determines whether the ignition key switch has been changed from the OFF position to the ON position.

[0074] If the ignition key switch has not been changed from the OFF position to the ON position, the CPU determines "No" in step 805, proceeds to step 895, and ends this routine for the time being.

[0075] On the other hand, if the ignition key switch is changed from the OFF position to the ON position, the CPU judges "Yes" in step 805 and proceeds to step 810. In step 810, the CPU judges whether or not the object position Pdr of the stationary object is stored in the EEPROM.

[0076] If the object position Pdr of the stationary object is not stored in the EEPROM, the CPU determines "No" in step 810 and proceeds to step 815. In step 815, the CPU sets the value of the dead reckoning flag Xdr to "0." After that, the CPU proceeds to step 895 and temporarily ends this routine.

[0077] On the other hand, if the object position Pdr of the stationary object is stored in the EEPROM, the CPU determines "Yes" in step 810 and executes steps 820 to 830 in order.

[0078] Step 820: The CPU acquires the current position of the vehicle VA as the on-vehicle position Pvon (on-position identification information). Step 825: The CPU obtains the moving distance Loff of the vehicle VA during the OFF period based on the ON-time vehicle position Pvon and the OFF-time vehicle position Pvoff. Step 830: The CPU determines whether the movement distance Loff is equal to or less than the threshold distance Lth.

[0079] If the travel distance Loff is equal to or less than the threshold distance Lth, the CPU determines "Yes" in step 830 and proceeds to step 835. In step 835, the CPU sets the value of the dead reckoning flag Xdr to "1". After that, the CPU proceeds to step 895 and temporarily ends this routine. If the travel distance Loff is equal to or less than the threshold distance Lth (i.e., if the vehicle VA is not moving during the off period), the positional relationship between the vehicle VA and the stationary object does not change between the off time and the on time. Therefore, even after the on time, estimation of the object position Pdr of the stationary object by dead reckoning continues. More specifically, in step 545 of the object recognition routine shown in FIG. 5, which is executed after the value of the dead reckoning flag Xdr is set to "1" in step 835, the object position Pdr of the stationary object is estimated.

[0080] On the other hand, if the moving distance Loff is greater than the threshold distance Lth, the CPU determines "No" in step 830 and proceeds to step 815, where it sets the value of the dead reckoning flag Xdr to "0". After that, the CPU proceeds to step 895 and ends this routine. If the moving distance Loff is greater than the threshold distance Lth (i.e., if the vehicle VA moves during the off period), the positional relationship between the vehicle VA and the stationary object changes between the on time and the off time. For this reason, after the on time, the object position Pdr of the stationary object is not estimated by dead reckoning. 5, which is executed after the value of the dead reckoning flag Xdr is set to "0" in step 815, step 545 is not executed. Therefore, the object position Pdr of a stationary object is not estimated.

[0081] As can be seen from the above, according to this control device, when the vehicle VA moves during the off period, the object position Pdr of a stationary object is not estimated by dead reckoning, thereby preventing the erroneous recognition of a stationary object that does not exist around the vehicle.

[0082] The present invention is not limited to the above-described embodiment, and various modifications can be adopted within the scope of the present invention.

[0083] (First Modification) The distance Lmin from the front end of the vehicle VA to the undetectable area NDA may be longer than the distance from the front end of the vehicle VA to the undetectable area NDA'. In this case, the DSECU 20 cannot recognize the object Ob located in the undetectable area NDA', determines that such an object Ob is a lost object, and estimates the object position Pdr by dead reckoning. The vehicle control device 10 needs to be equipped with at least one of the millimeter wave radar 21 and the forward camera 22, and the "sensor for detecting an object" equipped in the control device 10 may be referred to as an "object sensor". The millimeter wave radar 21 may be any remote sensing device capable of detecting a target by transmitting a wireless medium instead of millimeter waves and receiving the reflected wireless medium.

[0084] (Second Modification) In the above embodiment, the TTC is obtained based on the relative velocity Vr and object position P of the object Ob. However, the TTC may be obtained based on the relative acceleration, the relative velocity Vr and object position P of the object Ob. In the above embodiment, the index value is described by taking the TTC as an example, but the index value is not limited to the TTC, and may be the distance between the object Ob and the front end of the vehicle VA. Furthermore, in the above embodiment, deceleration control has been described as an example of vehicle control. However, the vehicle control is not limited to deceleration control, and may be acceleration limit control, warning control, steering control, braking force maintenance control, or the like. -Acceleration limit control Typically, the greater the depression amount of the accelerator pedal, the greater the driving force generated by the vehicle driving source (such as the engine 34). The acceleration limit control is a control that limits the driving force generated by the vehicle driving source so that it does not exceed a threshold driving force. Alarm control The warning control is a control for generating a buzzer sound from a speaker (not shown) to notify the driver of the presence of the object Ob. The warning control may be a control for displaying the position of the object Ob relative to the vehicle VA on a display (not shown). Steering control The steering control is a control for avoiding a collision with an object Ob by controlling a steering actuator (not shown) to change the steering angle of the steering wheels of the vehicle VA. Braking force maintenance control The braking force maintenance control is a control in which a predetermined braking force is continued to be generated by the brake actuator 42 even if the driver takes his / her foot off the brake pedal.

[0085] (Third Modification) The DSECU 20 of this modification stores the front image captured by the front camera 22 at the off time as off-position identification information in step 720 shown in Fig. 7. Furthermore, the DSECU 20 of this modification acquires the front image captured by the front camera 22 at the on time as on-position identification information in step 820 shown in Fig. 8. Then, the DSECU 20 of this modification determines whether the vehicle VA has moved during the off period by comparing the front image at the on time with the rear image at the off time. If a stationary object is located in the non-detectable area NDA at the off time, it is highly likely that only the stationary object is captured in the forward image. If the vehicle VA moves during the off period, the forward camera 22 captures a different landscape at the on time from that at the off time, so there is a high possibility that the forward image at the on time and the forward image at the off time will be significantly different. On the other hand, when the vehicle VA is not moving during the off period, the front camera 22 captures the same scenery at the off time and the on time, so there is a high possibility that the front image at the on time and the front image at the off time will be similar.

[0086] In this way, the off-position specifying information and the on-position specifying information do not have to be information capable of accurately specifying the current position of the vehicle VA at the time of off and the time of on, respectively. The off-position specifying information and the on-position specifying information only need to be information indicating "the position of the vehicle VA for determining whether or not the vehicle VA has moved during the off period," like the above-mentioned forward image.

[0087] (Fourth Modification) In the above embodiment, when an object that is unlikely to collide with the vehicle VA is no longer detected by the millimeter wave radar 21 and the front camera 22, the DSECU 20 regards the object as a lost object and performs dead reckoning. When an object that is unlikely to collide with the vehicle VA is no longer detected, the DSECU 20 of this modified example does not regard the object as a lost object and does not perform dead reckoning. In other words, only when an object (obstacle) that is likely to collide with the vehicle VA is no longer detected, the DSECU 20 of this modified example regards the object as a lost object and performs dead reckoning.

[0088] (Fifth Modification) In the OFF time storage routine, the storage device (storage medium) in which the stationary object position Pdr and the OFF time vehicle position Pvoff are stored may be any non-volatile storage medium and is not limited to an EEPROM. [Explanation of symbols]

[0089] 10...vehicle control device, 20...driving assistance ECU, 21...millimeter wave radar, 22...forward camera, 23...wheel speed sensor, 24...acceleration sensor, 25...steering angle sensor, 26...GNSS receiver, 30...engine ECU, 40...brake ECU.

Claims

[Claim 1] A millimeter wave radar that transmits millimeter waves in front of a vehicle and detects an object by receiving the millimeter waves reflected by the object; A state value sensor configured to detect a driving state value related to a driving state of the vehicle; a control unit configured to perform deceleration control for decelerating the vehicle when a control condition is satisfied that a time required for an object detected by the millimeter wave radar to collide with the vehicle is equal to or shorter than a threshold time; Equipped with The millimeter wave radar cannot detect an object located in a non-detectable area, which is an area less than a minimum detection distance from the millimeter wave radar, The control unit when an object that has been detected by the millimeter wave radar is positioned in the undetectable area and is no longer detected, executes a position estimation process to estimate an object position of the object that is no longer detected by the millimeter wave radar based on the traveling state value and an object position that is the position of the object relative to the vehicle when it was detected by the millimeter wave radar; When the position estimation process is being performed at an off time when the ignition of the vehicle is changed from an on state to an off state, if an object whose position has been estimated by the position estimation process is a stationary object, off position identification information capable of identifying the object position of the stationary object at the off time and the position of the vehicle at the off time is stored; When it is determined that the vehicle has not moved during a period from the off time point to the on time point based on on position specifying information capable of specifying the position of the vehicle at the on time point and the off position specifying information at an on time point when the ignition is changed from the off state to the on state, the object position of the stationary object is estimated by the position estimation process; when it is determined at the on time point that the vehicle has moved during the period based on the on position identification information and the off position identification information, the object position of the stationary object is not estimated by the position estimation process; It was configured as follows: Vehicle control device.

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