JP2015063220A - Drive assist system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a drive assist system capable of preventing both deterioration in fuel economy and degradation in ride quality of a vehicle that exerts a control to stop idling during vehicle driving.SOLUTION: A drive assist system 5 of the present invention for exerting a control to stop idling for temporarily stopping an engine of a vehicle during vehicle driving, includes: preceding vehicle detection means detecting a preceding vehicle; preceding -vehicle-behavior prediction means predicting a behavior of the preceding vehicle; driving interval determination means determining a driving interval the vehicle drives based on own-vehicle position information and map information; history information acquisition means acquiring history information on previous controls to stop idling in the driving interval; and permission/prohibition determination means determining whether to permit or prohibit execution of the control to stop idling on the basis of a prediction content predicted by the preceding vehicle behavior prediction means and the history information acquired by the history information acquisition means.

Description

  The present invention relates to a travel support device for a vehicle that performs idle stop control for temporarily stopping an in-vehicle engine when the driving / running state of the host vehicle satisfies a predetermined condition during travel.

  In recent years, in the field of vehicle control, for the purpose of improving fuel consumption and reducing exhaust gas, for example, it has become widespread to perform idle stop control in which, for example, the engine is temporarily stopped during travel and then restarted.

  In conventional idle stop control during traveling, the driver usually depresses the brake pedal, and when the speed of the host vehicle falls below a predetermined speed (low speed), the engine is stopped and the driver releases the brake pedal. When it does, the engine is restarted.

  Patent Document 1 discloses that when the driving / running state of a vehicle satisfies a predetermined condition during traveling, the engine is temporarily stopped, and when the condition is not satisfied, the engine is restarted using the kinetic energy of the vehicle. A control to start is disclosed.

JP 2012-127265 A

  However, even if the engine is stopped by the idle stop control, for example, when the preceding vehicle that has been decelerated starts to re-accelerate, the engine needs to be restarted immediately. In such a case, the state in which the engine is stopped in the idle stop control cannot be continued for a predetermined time or longer. As a result, the fuel consumption is better if the idle stop control is not performed, and the effect of improving the fuel consumption by the idle stop control is obtained. I can't. Further, since the vehicle cannot be accelerated until the engine is restarted, the response becomes dull and the ride comfort of the occupant may be impaired.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a driving support device capable of preventing both a deterioration in fuel consumption and a decrease in riding comfort of a vehicle that performs idle stop control during driving. It is to be.

  The vehicle travel support device of the present invention that solves the above problems is a vehicle travel support device that performs idle stop control for temporarily stopping the engine of the host vehicle while traveling based on a predetermined idle stop condition. A preceding vehicle detecting means for detecting a preceding vehicle, a preceding vehicle behavior predicting means for predicting the behavior of the preceding vehicle, and a traveling section determination for determining a traveling section in which the own vehicle is traveling based on the own vehicle position information and map information Means, history information acquisition means for acquiring past history information of the idle stop control in the travel section, prediction contents predicted by the preceding vehicle behavior prediction means, and history information acquired by the history information acquisition means Based on whether or not the idle stop control is permitted or prohibited.

  According to the present invention, it is possible to reduce the occurrence rate of idle stop failure that is restarted before a predetermined time has elapsed after the engine is stopped by the idle stop control, thereby reducing vehicle fuel consumption and ride comfort. Both can be prevented. Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram which shows one Example of the driving assistance device of the vehicle which concerns on this invention with the vehicle to which it is applied. The functional block diagram which shows the principal part of the driving assistance apparatus of the vehicle shown by FIG. A figure used for explanation of the relationship between the vehicle and the preceding vehicle when following the preceding vehicle The figure used for explanation of the relationship between the own vehicle and the preceding vehicle at the time of the preceding vehicle following traveling on a slope. The flowchart explaining the processing content of the control routine by the driving assistance device in this Embodiment. The schematic of the map for demonstrating the content of map information. The graph which shows the average value of idle stop continuation time. The figure explaining the shortest time of the idle stop continuation time commensurate with the amount of fuel consumption increase. Normal distribution map of idle stop duration. The flowchart which shows an example of the processing content of the idle stop control routine which a vehicle integrated control unit performs, and its procedure. The flowchart which shows an example of the implementation result registration method of idle stop control. The flowchart which shows an example of the method of determining whether log | history information is equipped with log | history conditions. The flowchart which shows an example of the method of determining whether log | history information is equipped with log | history conditions. The flowchart which shows an example of the method of determining whether log | history information is equipped with log | history conditions. The flowchart explaining the update method of log | history information. The figure explaining the condition where the availability determination of idle stop control is made.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a schematic block diagram showing an embodiment of a vehicle driving support apparatus according to the present invention together with a vehicle to which the vehicle driving support apparatus is applied. FIG. 2 shows a main part of the vehicle driving support apparatus shown in FIG. It is a functional block diagram.

  The illustrated vehicle 1 includes, for example, an in-cylinder injection gasoline engine 10 as a driving power source, an automatic transmission 12 that can be connected to and separated from the engine 10, a propeller shaft 13, a differential gear 14, a drive shaft 15, This is a rear-wheel drive vehicle having a general configuration including wheels 16 and a hydraulic brake 18.

  The vehicle 1 includes a vehicle integrated control unit 20 that constitutes a main part of the driving support device 5 of the present invention that controls integrated control of devices, actuators, and devices mounted on the vehicle 1, and an engine control unit 30 that controls engine control. A control unit with a built-in microcomputer, such as a transmission control unit 40 that controls transmission, is disposed at a predetermined portion.

  Devices, actuators, and devices including each control unit and sensors, which will be described later, can exchange signals and data through an in-vehicle LAN (CAN).

  A stereo camera 17 is provided at the front of the vehicle 1. This stereo camera 17 has a control unit part with a built-in microcomputer, and the control unit part is based on the captured image, the relative speed of the preceding vehicle with the own vehicle, the preceding vehicle in front of the own vehicle, The distance between the obstacle, the oncoming vehicle, etc. and the own vehicle (inter-vehicle distance, etc.), the height from the road surface at the lower end of the body of the preceding vehicle, etc. are calculated and supplied to the vehicle integrated control unit 20.

  The vehicle integrated control unit 20 detects four wheel speed sensors 21 that detect the rotational speed of each wheel 16, an accelerator pedal sensor 26 that detects the opening (depression amount) of the accelerator pedal 25, and a depression amount of the brake pedal 27. A signal is also supplied from the brake sensor 28, the gyro sensor 19 that detects the gradient of the vehicle, the car navigation system 60, and the like.

  The illustrated vehicle 1 is an example of a vehicle to which the present invention is applicable, and does not limit the configuration of the vehicle to which the present invention can be applied.

  For example, a vehicle that employs a continuously variable transmission (CVT) instead of the automatic transmission 12 may be used, and one of a laser radar, a millimeter wave radar, a mono camera, and the like may be used as an external recognition sensor instead of the stereo camera 17. The relative speed, the inter-vehicle distance, and the like may be obtained using one or a plurality of combinations.

  Further, the depression amount of the brake pedal 27 is detected not only by the brake sensor 28 but also by a hydraulic pressure sensor (not shown) for detecting the brake hydraulic pressure in the control system of the brake 18.

  In addition to signals and data from control units such as the vehicle integrated control unit 20 and the transmission control unit 40, the engine control unit 30 includes an operation state of the engine 10 (engine The engine control unit 30 will be described later on the basis of these signals. The engine control unit 30 will be described later based on these signals, representing the rotational speed, intake air amount, throttle opening, in-cylinder pressure, etc.). As shown in FIG. 2, a predetermined control signal is supplied to the fuel injection valve 31, an ignition unit 33 including an ignition coil, an ignition plug, and the like, an electric throttle valve 34, etc., and fuel injection (amount) control, Ignition (timing) control, throttle opening control, etc. are executed.

  The driving support device 5 predicts the kinetic energy required for the vehicle in the future based on the kinetic energy of the own vehicle, the speed of the preceding vehicle, and the inter-vehicle distance from the preceding vehicle during the preceding vehicle following traveling. Based on the predicted kinetic energy and the current kinetic energy, it is determined whether or not there is sufficient kinetic energy (following kinetic energy) that the vehicle can follow the preceding vehicle by coasting. When it is determined that there is sufficient kinetic energy, and the driving / running state of the vehicle satisfies other idle stop conditions, the engine is temporarily stopped while the vehicle is running. .

  Next, the determination of whether the following kinetic energy is sufficient or insufficient will be described with reference to FIGS.

FIG. 3 shows a state where the host vehicle and the preceding vehicle are traveling on a flat road. FIG. 3A shows the relationship between the host vehicle and the preceding vehicle at time t = 0, and FIG. This represents an expectation when the host vehicle reaches the coordinate P (L, 0) by inertia traveling from the time t = 0 and the coordinate P (0, 0), and the time at that time is t = T (seconds). 3A and 3B (and FIG. 4 described later),
v ₁ : Current host vehicle speed V ₁ : Current preceding vehicle speed L: Current inter-vehicle distance v ₂ : Host vehicle speed after T seconds.

  As shown in FIG. 2, the vehicle speed is calculated based on signals from the four wheel speed sensors 21, and the preceding vehicle speed is based on the vehicle speed and the relative speed obtained from the stereo camera 17. Is calculated.

3 (A) and 3 (B), it can be seen that the following equation (1) needs to be established in order for the vehicle to follow the preceding vehicle in inertial running.
v ₂ > V ₁ (1)

  From equation (1), if m is the vehicle weight and A is the predicted deceleration, the following equation (2) can be derived.

  The own vehicle weight m is calculated as a weight obtained by adding the loading weight at the time of the current driving operation to a fixed value by internal processing, and the predicted deceleration A is based on the rate of change of the own vehicle speed because it is inertial driving. For example, it is expressed as 0.1 [G].

  The first term on the left side of Equation (2) is the current kinetic energy of the host vehicle, and the second term on the left side is the minimum when the host vehicle passes the coordinate P (L, 0) that is the current position of the preceding vehicle. Necessary kinetic energy. In other words, the second term on the left side is the predicted kinetic energy when the host vehicle is assumed to travel at the preceding vehicle speed. Therefore, the left side represents surplus kinetic energy, which is the difference between the kinetic energy of the host vehicle and the kinetic energy when the host vehicle is assumed to travel at the preceding vehicle speed.

  Further, the right side of the expression (2) stops the engine until the vehicle 1 reaches the coordinate P (L, 0) that is the current position of the preceding vehicle from the coordinate P (0, 0) that is the current position. This is the lost kinetic energy of the vehicle when coasting.

Therefore, Equation (2) shows that the surplus kinetic energy of the own vehicle is larger than the loss kinetic energy. If Equation (2) is satisfied, it can be said that the following kinetic energy is sufficient, and the own vehicle is inertial. The coordinates P (L, 0) can be passed at a speed equal to or higher than V ₁ by traveling.

  On the other hand, as shown in FIGS. 4 (A) and 4 (B), when the vehicle is traveling uphill, the above equation (1) is a relational equation such as equation (3) when the running resistance and the gradient are taken into account. It can also be expressed.

In FIG.
h: Relative height of the preceding vehicle. The relative height h of the preceding vehicle is calculated based on the gradient of the preceding vehicle and the inter-vehicle distance L. As shown in FIG. 2, the gradient of the preceding vehicle is, for example, the own vehicle speed and engine torque, the height position of the lower end of the vehicle body of the preceding vehicle obtained from the stereo camera 17, the own vehicle gradient obtained from the gyro sensor 19, etc. Is calculated (estimated) based on

Moreover, in Formula (3),
a (t): Traveling resistance at time t v (t): Vehicle speed at time t: Gravity acceleration.

  The left side of equation (3) is the same as equation (2) and is the kinetic energy of the current vehicle, and the second term on the left side passes through the coordinates P (L, H) where the vehicle is the current position of the preceding vehicle. This is the minimum kinetic energy that is required. In other words, the second term on the left side is the predicted kinetic energy when the host vehicle is assumed to travel at the preceding vehicle speed. Therefore, the left side represents surplus kinetic energy, which is the difference between the kinetic energy of the host vehicle and the kinetic energy when the host vehicle is assumed to travel at the preceding vehicle speed.

  The first term on the right side is the energy lost in the running resistance when the inertial running is performed with the engine stopped from the coordinates P (0, 0) to the coordinates P (L, H), and corresponds to the right side of the equation (2). To do. The second term on the right side is the relative potential energy of the coordinates P (L, H). That is, the right side of Equation (3) indicates the loss energy necessary for the host vehicle to reach the coordinates P (L, H) from the coordinates P (0, 0).

Therefore, the equation (3) shows a relationship in which the surplus kinetic energy of the own vehicle is larger than the lost kinetic energy. If the equation (3) is satisfied, it can be said that the following kinetic energy is sufficient, and the own vehicle is inertial. coordinates P (L, H) to be passed at _{V 1} or more speed travel.

  Next, the idling stop control at the time of the preceding vehicle follow-up travel performed by the travel support device 5 of the present embodiment will be described in detail.

  The driving support device 5 of the present embodiment includes a vehicle control unit 20 as a main part. As shown in the functional block diagram of FIG. 2, the vehicle control unit 20 includes surplus kinetic energy calculation means 51, lost kinetic energy calculation means 52, follow-up kinetic energy presence / absence determination means 53, and idle stop availability determination. Means 55 (appropriateness determination means).

  The surplus kinetic energy calculating means 51 is based on the difference between the kinetic energy of the own vehicle and the predicted kinetic energy of the own vehicle when the own vehicle is assumed to travel at the preceding vehicle speed V based on the own vehicle weight m and the own vehicle speed v. Calculate some surplus kinetic energy.

  The lost kinetic energy calculation means 52 is based on the own vehicle weight m, the predicted deceleration A or running resistance of the own vehicle, the inter-vehicle distance L with the preceding vehicle, and the relative height h of the preceding vehicle, and the lost kinetic energy of the own vehicle. Is calculated.

  Based on the surplus kinetic energy and the loss kinetic energy, the tracking kinetic energy presence / absence determining means 53 has sufficient kinetic energy (following kinetic energy) that the vehicle can follow the preceding vehicle by inertial running. Determine if it is missing. Here, if the surplus kinetic energy is larger than the loss kinetic energy, it is determined that the following kinetic energy is sufficient. If the surplus kinetic energy is smaller than the loss kinetic energy, the following kinetic energy is insufficient. Is determined.

The idle stop propriety judging means 55
(A) When it is determined that the following kinetic energy is sufficient and other idle stop conditions are satisfied, an engine stop command is output to the engine control unit 30. Other idle stop conditions include, for example, that the accelerator pedal 24 is not depressed as the driving / running state of the own vehicle, and that the idling stop control is prohibited while the running section of the own vehicle is running. This includes that it is not a prohibited section, that the current position is an idle stop continuation section, and that execution of idle stop control is permitted based on history information.
(B) When it is determined that the following kinetic energy is insufficient during idle stop (engine stop), an engine restart command is output to the engine control unit 30.
(C) When the depression of the accelerator pedal 24 is detected while the engine is stopped, an engine restart command is output to the engine control unit 30.
(D) While the depression of the brake pedal 27 is detected during low-speed traveling, an engine stop command is output to the engine control unit 30 even when it is determined that the following kinetic energy is insufficient.
(E) When it is determined that the following kinetic energy is sufficient during high-speed traveling, the idle stop condition during high-speed traveling (for example, the accelerator pedal 24 is not depressed) regardless of whether the brake pedal is depressed. Etc.), an engine stop command is output to the engine control unit 30.

  When the engine control unit 30 receives an engine stop command from the idle stop propriety determination means 55, the engine control unit 30 stops supplying the fuel injection (drive) pulse signal to the fuel injection valve 31 and further supplies the ignition signal to the ignition unit 33. Stop. As a result, the engine stops. Further, the engine control unit 30 resumes the supply of the fuel injection (drive) pulse signal to the fuel injection valve 31 when the engine restart command is received from the idling stop availability determination means 55, and further the ignition signal to the ignition unit 33. Supply will resume. This restarts the engine.

  In addition, when the engine stop command is output to the engine control unit 30, the idle stop propriety determination unit 55 outputs an engine shut-off command to the transmission control unit 40 and outputs an engine restart command at the same time. At the same time, an engine connection command is output to the transmission control unit 40. As a result, when the engine is stopped, the engine 10 and the transmission 12 are mechanically separated from each other and the engine brake is not applied, so that the running resistance is reduced. Further, after the engine is restarted, the engine 10 and the transmission 12 are connected and normal power transmission is performed.

  FIG. 5 is a flowchart for explaining the processing contents of the control routine by the driving support apparatus in the present embodiment.

  First, in step S101, processing for detecting a preceding vehicle is performed (preceding vehicle detection means). The preceding vehicle is detected based on an image captured by the stereo camera 17, for example, the preceding vehicle is detected by pattern matching, the inter-vehicle distance from the preceding vehicle is calculated by parallax, and the preceding vehicle is detected from the relative speed with the own vehicle. Calculate vehicle speed and acceleration / deceleration.

  Next, in step S102, processing for predicting the behavior of the preceding vehicle based on the preceding vehicle detection result is performed (preceding vehicle behavior predicting means). For example, it is predicted that the preceding vehicle will stop based on the vehicle speed and deceleration of the preceding vehicle, and the preceding vehicle stop prediction time until the preceding vehicle falls below a predetermined speed is calculated.

  And in step S103, the process which determines the traveling area in which the own vehicle is drive | working based on the own vehicle position and map information is performed (traveling section determination means). The travel section includes an idle stop continuation section that is set for preventing fuel consumption deterioration and an idle stop prohibition section that is set for preventing a decrease in riding comfort.

  The idle stop continuation section and the idle stop prohibition section have different uses. The idle stop continuation section is set to prevent deterioration of fuel consumption, and the idle stop prohibition section is set to prevent a decrease in riding comfort.

  FIG. 6 is a schematic diagram of a map for explaining the contents of the map information. For example, the car navigation system 60 has the map information. A portion indicated by a straight line in FIG. 6 is a road R, and an idle stop continuation section is set as shown in FIGS. 6A and 6B, and as shown in FIGS. 6C and 6D. In addition, an idle stop prohibition section is set.

  In the idle stop continuation section, history information of idle stop control is associated and stored, and can be read based on the vehicle position information. The history information includes a control result of idle stop control actually performed by the host vehicle in the past, and may include a control result of another vehicle. The control result actually performed by the host vehicle is stored as new history information in the database in the car navigation 60 from the history information storage means 57 provided in the vehicle 1, for example, and is read from the database in the car navigation 60 by the history information acquisition means 56. It is.

  The history information of the own vehicle or the other vehicle may be stored in a database in the car navigation system 60. For example, the history information of the own vehicle or another vehicle is stored in a database of an information center connected via a communication network. It is good also as a structure read from a database according to a request and supplied to the own vehicle from an information center.

  The idle stop prohibition section is set as a place where the response may deteriorate if the engine is stopped by idle stop control, such as in an intersection at the time of turning left or right, and the ride comfort may be deteriorated. It is forbidden. The idle stop prohibition section has no history information and is set in advance by an occupant such as a driver. And a time slot | zone may be set and implementation of idle stop control may be prohibited in the time slot | zone.

  Next, in step S104, processing for acquiring history information of idle stop control in a travel section in which the host vehicle is traveling is performed (history information acquisition means). The history information includes (1) average duration time, (2) failure rate, (3) control rate, and (4) reliability information for each time. For example, for (a) in FIG. 6, the continuation average time is set to 3 seconds, the failure rate is 60%, the control rate is 5%, and the reliability is 30%. For (b) in FIG. The time is set to 6 seconds, the failure rate is 40%, the control rate is 10%, and the reliability is 20%.

  As a method for determining the idle stop continuation section, the idle stop control may be ended from the position where the idle stop control is started. Also, in cases where idle stop continuation sections are sparsely installed around the intersection, the far section that is far from the intersection is set as the start position, and the section closest to the intersection is grouped as the end section. Two new idle stop continuation intervals may be set. Note that the location to be newly set as the idle stop continuation section is not limited to the intersection, but may be a road shape in which the idle stop control such as a curve or a slope frequently fails.

(1) The duration average time is represented by the section duration average value (μ) obtained by dividing the total idle stop duration time of the vehicle by the number of idle stop controls. FIG. 7 is a graph showing the section duration average value for each time in FIG. The section duration average value (μ) is calculated by calculating “the total number of idle stop durations in a given section / the number of idle stops in a given section” for a given time in a given section in which the vehicle has traveled. Is done.

(2) The failure rate represents how many times the idle stop has failed with respect to the number of times the idle stop control is performed. That is, it is the ratio of idle stop failure as a result of performing the idle stop control in the traveling section. The failure rate is calculated by the following calculation formula.

  Failure rate (%) = (the number of idle stop failures in a predetermined section / the number of idle stops performed in a predetermined section) × 100

  The idle stop failure is defined as a case where the idle stop duration is less than the reference time. The reference time for determining the idle stop failure is related to fuel injection at the time of engine restart, and also depends on the type of engine.

  FIG. 8 is a graph showing the fuel consumption when the engine is restarted. The fuel consumption per unit time when an engine with a displacement of 2000 cc is restarted with the automatic transmission range being N range and no load. It shows the transition of quantity. The fuel consumption during idling is 0.221 cc / sec, and the fuel increase accompanying engine restart is 1.05 cc. Therefore, the minimum idle stop duration time corresponding to the increase in fuel consumption is 1.05 ÷ 0.221 = 5 (sec), which is 5 seconds, and the reference time for determining the success or failure of the idle stop is set. It can be 5 seconds. That is, when the idle stop duration is 5 seconds or more, the idle stop is successful, and when it is less than 5 seconds, the idle stop is failed.

(3) The control rate represents how much the idle stop control is performed with respect to the number of times of travel in the travel section, and is a ratio of the idle stop control performed in the travel section. The control rate is calculated by the following calculation formula.

  Control rate (%) = (the number of idle stops in the travel section / total number of travels in the section at a certain time) × 100

  In addition, the frequency | count of a driving | running | working area shows how many times the own vehicle drive | worked in the area of a certain time. In short, the control rate represents what percentage of idling stop control is executed.

(4) The reliability is an index indicating how much history information may be trusted when the vehicle uses the history information. FIG. 9 is a normal distribution diagram of idle stop duration. For the reliability, the standard deviation of the idle stop duration is obtained by the following formula.

Standard deviation (σ) = √ (((total idle stop duration in running section−average idle stop duration in running section) ² ) ÷ total number of idle stops in running section)

  A method may be considered in which this standard deviation is treated as a reliability value, and idle stop control is permitted for those that do not exceed a threshold value. Since the value increases as the variation in the duration time increases, the history information is trusted as the variation decreases. Further, hereinafter, for a normal distribution, as shown in FIG. 9, a value obtained by the following calculation can be treated as a reliability value according to a confidence interval of 95% reliability.

  Confidence interval minimum value = interval duration average (μ)-(1.96 x standard deviation (σ)) ÷ √ Number of idle stops in the running section

  The confidence interval means that 95% of cases where the idle stop control is performed in the traveling interval falls within the following interval duration.

  Section duration average value (μ) − (1.96 × standard deviation (σ)) ÷ √ Section duration average value (μ) + (1.96 × standard deviation (σ)) from the number of idle stops in the section ÷ √ Idle stop in the section

  Therefore, the idea is that if the minimum value of the confidence interval is used and a certain threshold value is exceeded, the idle stop duration time is not short enough to deteriorate the fuel consumption.

  In step S105, a process of determining whether or not the idle stop control can be performed based on the prediction content of the preceding vehicle behavior predicted by the preceding vehicle behavior prediction process of step S102 and the history information acquired by the history information acquisition process of step S104. Is done.

  Therefore, when the idle stop control is performed, the idle stop success can be increased, the idle stop failure can be reduced, and both the deterioration of the fuel consumption of the vehicle and the decrease of the ride comfort can be prevented.

  Next, an example of the processing contents and the procedure of the idle stop control routine during travel (during the preceding vehicle following travel) executed by the vehicle integrated control unit 20 will be described with reference to the flowchart of FIG. This routine is repeatedly executed every predetermined time (cycle).

FIG. 10 explains the contents of the process shown in FIG. 5 more specifically.
First, in steps S111 to S113, it is confirmed that the current position of the host vehicle is not an idle stop prohibition section in which idle stop during prohibition of preceding vehicle follow-up is prohibited. Next, in step S114 to step S116, the stop of the preceding vehicle is predicted as the behavior of the preceding vehicle, and it is confirmed that the following kinetic energy of the own vehicle is sufficient. It is determined whether or not the camera is in a state where it is possible. In steps S117 to S120, a process for determining whether or not the idle stop control can be performed based on the history information of the idle stop control in the traveling section is performed.

  In step S111, an idle stop prohibited section list is acquired around the vehicle position. The idle stop prohibition section list is a list of a plurality of prohibition sections such as prohibition sections (c) and (d) shown in FIG. The position information and map information of the own vehicle are acquired from the car navigation system 60 or an information center connected via a communication network. The idle stop prohibition section is stored in the database of the car navigation system 60 or the database of the information center in a form associated with the map information as a list, and is read based on the position information of the own vehicle. The idle stop prohibition section list may inquire the information center of the idle stop prohibition section according to whether the ride comfort by the idle stop is good according to the characteristics of the vehicle.

  In step S112, a section through which the host vehicle passes next is calculated from the position information of the host vehicle and map information, and a corresponding idle stop prohibited section list is acquired. In step S113, it is determined whether the current position of the host vehicle is not in the idle stop prohibition section. If it is not in the idle stop prohibition section (Yes in step S113), it is determined whether a preceding vehicle is detected in step S114. Is done. When a preceding vehicle is detected (Yes in step S114), the process proceeds to step S115 and subsequent steps in order to determine whether the preceding vehicle is predicted to stop and whether or not the following vehicle has sufficient tracking kinetic energy. Further, when it is an idle stop prohibition section (No in step S113) or when a preceding vehicle is not detected (No in step S114), the process proceeds to step S120 to prohibit the execution of the idle stop.

  In step S115, a process for calculating the predicted stop time of the preceding vehicle and whether there is sufficient follow-up kinetic energy for the host vehicle until the preceding vehicle stops is performed. The predicted stop time of the preceding vehicle is determined based on the vehicle speed and deceleration of the preceding vehicle, and is the time until the vehicle speed of the preceding vehicle becomes equal to or lower than the predetermined speed.

  In step S116, it is determined whether or not the vehicle is in a state where it is possible to perform idle stop control. Specifically, the preceding vehicle is predicted to stop, and the vehicle's follow-up kinetic energy is sufficient. It is judged by whether or not the condition of being in is satisfied. The stop prediction of the preceding vehicle is determined based on the predicted stop time calculated in step S115.

  If it is determined that this condition is satisfied (Yes in step S116), the process proceeds to step S117 to determine whether or not the idle stop control is possible based on the history information of the idle stop control. On the other hand, if it is predicted that the preceding vehicle will stop and that the condition that the vehicle's following kinetic energy is sufficient is not satisfied (No in step S116), the idle stop is prohibited. Therefore, the process proceeds to step S120.

  In step S117, a process for evaluating whether or not to permit the execution of the idle stop control based on the history information of the idle stop control is performed. The idle stop continuation section has history information for each time. When carrying out the idle stop control, the own vehicle reads out the history information of the idle stop control in the time zone closest to the current time corresponding to the traveling idle stop continuation section and uses it in the own vehicle logic.

  In step S118, a process of determining whether or not the idle stop control can be performed based on the evaluation result of step S117 is performed. Additional information for determining whether or not to implement idle stop control to further improve fuel efficiency, such as vehicle type information such as the displacement of the vehicle, driver information, time zone information such as day and night, weather May be used.

  When the history information satisfies a certain condition (Yes in step S118), the process proceeds to step S119, and the implementation of the idle stop control is permitted (Yes in step S118). On the other hand, when the history information does not satisfy a certain condition (No in step S118), the process proceeds to step S120 and the execution of the idle stop control is prohibited.

  FIG. 11 is a flowchart illustrating an example of an idle stop control execution result registration method.

  When the idle stop control is performed, a process for registering the execution result, that is, whether the idle stop is successful or the idle stop failure, in the history information is performed. First, in step S201, the idle stop duration is counted, and in step S202, it is determined whether or not to cancel the idle stop control. The idle stop control is canceled when a predetermined condition is not satisfied, for example, an operation of depressing the accelerator pedal is performed.

  If it is determined in step S203 that the idle stop control is cancelled, the process proceeds to step S204, and a process for canceling the idle stop control is performed. On the other hand, if it is not determined in step S203 to cancel the idle stop control, the process returns to step S201, and the idle stop duration time is counted again.

  When the idle stop control is canceled in step S204, it is determined whether or not the idle stop duration is shorter than the reference time. If it is shorter than the reference time, the process proceeds to step S206, where it is determined that the idle stop has failed, and failure information is transmitted in step S207. The failure information includes the vehicle position where the idle stop has failed, the idle stop duration, and the like. On the other hand, if the idle stop duration is equal to or longer than the reference time, the process proceeds to step S208, where it is determined that the idle stop is successful, and success information is transmitted in step S209. The success information includes the vehicle position where the idle stop was successful, the idle stop duration, and the like. Failure information and success information are transmitted to the storage means and information server of the own vehicle, and are used for updating history information.

  12 to 14 are flowcharts illustrating an example of a method for determining whether or not history information includes a history condition. The provision of the history condition here means that the condition for determining whether or not to perform the idle stop control may be determined using the history information.

  In the case of the example shown in FIG. 12, in step S301, it is determined whether or not the number of executions of the idle stop control is greater than or equal to a predetermined reference number, and it is determined whether or not history information that has performed the idle stop is accumulated to some extent. . If the number of times is equal to or greater than the reference number, the history information is accumulated to some extent, and the process proceeds to the determination of the control rate in step S302.

  In step S302, it is determined whether the control rate is equal to or higher than a reference. Here, it is determined how much the idling stop control is performed out of the number of running times, and if the idling stop control can be performed every time, it is determined that the control rate is equal to or higher than the reference, and the failure rate of step S303. Proceed to the determination. In step S303, it is determined whether or not the failure rate is equal to or less than a reference. If the failure rate is equal to or less than a predetermined value (if not so much failed), the process proceeds to step S304 for determining reliability.

  In step S304, it is determined whether or not the section standard deviation is less than or equal to a reference. If the section standard deviation is less than or equal to the reference, it is determined that the reliability is high (the reliability is greater than or equal to the reference). This is because the greater the variation in idle stop duration, the greater the section standard deviation value, and the smaller the variation, the higher the reliability.

  Then, the process proceeds to step S305, where it is determined that the history condition for performing the idle stop control is provided. It is also determined that the history condition is provided when the number of implementations is small or when the control rate is less than a predetermined value. On the other hand, when the failure rate and the section standard deviation are higher than the reference, it is determined that the history condition for performing the idle stop control is not provided.

  In the case of the example shown in FIG. 13, the method for determining the reliability in step S314 is different from the example shown in FIG. In step S314, it is determined whether or not the confidence interval minimum value is equal to or greater than a predetermined value, and if it is equal to or greater than the predetermined value, it is determined that the reliability is high.

  In the example shown in FIG. 14, evaluation is performed by calculating the fuel consumption without using the failure rate. Steps S301 and S302 are the same as the example shown in FIG. 12. In step S323, it is determined whether or not the section standard deviation is equal to or smaller than a predetermined value. If the section standard deviation is less than or equal to the predetermined value, there is little variation in the idle stop continuation time, so it is determined that the reliability is high, and the process proceeds to step S324 and thereafter.

  In step S324, the fuel reduction amount at the time of success is calculated, and in step S325, the fuel deterioration amount at the time of failure is calculated. The fuel reduction amount and the fuel deterioration amount are calculated by the following formulas.

  Then, in step S326, the fuel reduction amount is compared with the fuel deterioration amount at the time of failure. If the reduction amount is larger, the process proceeds to step S327, and the history condition for performing the idle stop control is provided. To be judged. If the reduction amount is smaller, the process proceeds to step S328, and it is determined that the history condition for executing the idle stop control is not provided.

FIG. 15 is a flowchart for explaining a history information update method.
When the vehicle has finished traveling in the travel section, processing for updating the history information of the idle stop control is performed. However, this is limited to the case where idle stop control is performed in the target section.

  First, when it is determined in step S401 that the vehicle has finished running through the travel section, an average value of idle stop durations is calculated in step S402, and a control rate is calculated in step S403. In step S404, the failure rate in the travel section is calculated, and in step S405, the reliability is calculated. In step S406, each piece of information calculated in steps S402 to S405 is mapped to map information and associated with the travel section of the map.

  FIG. 16 is a diagram illustrating a specific example of a situation in which it is determined whether or not idle stop control is possible. FIG. 16 (A) is a diagram schematically showing Xkm square map information of the vehicle position, and FIGS. 16 (B) to 16 (E) are (1) to (4) of FIG. 16 (A). ) Is an enlarged view of each case.

  In the case of (1), if the idle stop control is performed only by detecting the preceding vehicle as in the conventional case, the engine stops at the intersection, and the preceding vehicle itself does not want to stop but decelerates. As a result, the acceleration sensitivity of the vehicle may be deteriorated. On the other hand, in this embodiment, since the idle stop prohibition section C1 is set in the T-junction intersection, when the vehicle enters the T-junction while turning right from the side road to the main road, Even if there is a preceding vehicle, the engine is not stopped by the idle stop control, and it is possible to prevent the acceleration sensitivity of the own vehicle from being impaired at the intersection.

  In the case of (2), there is a place where the prospect is bad on the curve, and when the preceding vehicle decelerates to make a right turn on the right turn road, conventionally, the own vehicle has been subjected to idle stop control. However, if the preceding vehicle immediately turns right, the vehicle must immediately release the idle stop control and restart the engine, which may cause an idle stop failure. In the case of (3), when the preceding vehicle decelerates on an uphill but then accelerates, conventionally, the idle stop control of the own vehicle is performed due to a decrease in the speed of the preceding vehicle, the engine stops, and the engine immediately stops. Stop control was canceled and the engine was restarted, which could cause idle stop failure. In the case of (4), when approach and separation from the preceding vehicle are repeatedly performed due to traffic jams, conventionally, engine stop by idle stop control and engine restart by release of idle stop control are performed in a short time. Repeatedly, there was a risk of idle stop failure.

  On the other hand, in this embodiment, since the idle stop continuation section C2 is set at the locations (2) to (4), the implementation of the idle stop control is prohibited, and the idle stop failure is prevented. Can do.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various designs can be made without departing from the spirit of the present invention described in the claims. It can be changed. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described. Further, a part of the configuration of an embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of an embodiment. Furthermore, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

DESCRIPTION OF SYMBOLS 1 Vehicle 5 Travel assistance apparatus 20 Vehicle integrated control unit 17 Stereo camera (preceding vehicle detection means)
53 Tracking kinetic energy presence / absence determination means (preceding vehicle behavior prediction means)
55 Idle stop availability determination means (Availability determination means)
60 Car navigation system (travel section judgment means)

Claims (6)

A traveling support device for a vehicle that performs idle stop control for temporarily stopping an engine of the vehicle during traveling based on a predetermined idle stop condition,
A preceding vehicle detection means for detecting a preceding vehicle;
Preceding vehicle behavior predicting means for predicting the behavior of the preceding vehicle;
Traveling section determination means for determining a traveling section in which the vehicle is traveling based on the vehicle position information and map information;
History information acquisition means for acquiring past history information of the idle stop control in the travel section;
Availability determination means for determining permission or prohibition of execution of the idle stop control based on the prediction content predicted by the preceding vehicle behavior prediction means and the history information acquired by the history information acquisition means;
A driving support device comprising:   The availability determination unit determines that the execution of the idle stop control is permitted when the preceding vehicle behavior prediction unit predicts the stop of the preceding vehicle and the history information includes a preset history condition. The travel support apparatus according to claim 1, wherein The history information includes information on the number of times the idle stop control has been performed in the travel section, information on a control rate that is a ratio of the idle stop control performed in the travel section, and the idle stop control in the travel section. As a result, information on the failure rate, which is the rate of idle stop failure when the idle stop duration is less than the reference time, and information on the reliability of idle stop control in the travel section are included,
The availability determination means includes the history when the number of executions of the idle stop control in the travel section is a reference number or more, the control rate is a reference or more, the failure rate is higher than a reference, and the reliability is a reference or more. 3. It is determined that a condition is satisfied, and when the failure rate is higher than a reference, or when the reliability is less than a reference, it is determined that the history condition is not provided. The driving support device according to 1.   4. The travel according to claim 3, wherein the availability determination unit determines that the history condition is satisfied when the number of executions is less than a reference number or when the control rate is less than a reference. Support device. As a result of performing the idle stop control in the travel section, it is determined whether the idle stop success time when the idle stop duration time is equal to or longer than a preset reference time or the idle stop failure time when the idle stop duration time is less than the reference time. Control result determination means;
History information update means for updating the history information using the determination result of the control result determination means;
The driving support device according to claim 1, wherein   2. The history information acquisition unit acquires the history information from at least one of a history information storage unit of the own vehicle or an information center connected via a communication network. Driving support device.

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