JP2007168741A - Vehicle control device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle control device and a method capable of controlling an own vehicle so as to reduce speed without giving uncomfortable feeling to a driver by properly deciding a speed reducing means in response to an estimated travelling condition of the own vehicle after reducing speed. <P>SOLUTION: In the case of reducing speed of the own vehicle on the basis of road information and a real vehicle speed, a speed reduction target point and a target car speed are decided, and a gear ratio of a transmission mechanism for properly reducing speed by an engine brake is decided on the basis of the real vehicle speed, the target vehicle speed and a distance to the speed reduction target point. In the case that the traveling condition quantity of the own vehicle when speed is reduced to the target vehicle speed at the decided gear ratio is a predetermined condition threshold which is determined based on a lower limit value of the travelling condition quantity wherein the engine brake is operated as a reference or more, speed reduction control using the engine brake is decided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle control apparatus and method for performing vehicle control for decelerating a host vehicle by an appropriate deceleration method according to the situation.

  As a technique related to a vehicle control apparatus that performs vehicle control for decelerating the host vehicle by an appropriate deceleration method according to the situation, for example, the following technique is disclosed in Patent Document 1 below. This vehicle control device calculates the radius of the curve when a curve exists in the traveling direction of the host vehicle based on the road data stored in the storage means. Next, based on the curve radius and the road surface friction coefficient, a target speed for turning the curve without difficulty is calculated. Then, based on the target speed, the current host vehicle speed, the distance to the curve, and the road surface friction coefficient, the engine brake and the wheel brake by the downshift are operated to execute control for appropriately decelerating the host vehicle. At this time, at the same vehicle speed, the deceleration amount is increased as the road surface friction coefficient is higher. In addition, with the same road surface friction coefficient, the engine brake and the wheel brake are operated so that the higher the vehicle speed, the higher the engine brake operating ratio.

Japanese Patent Laying-Open No. 2005-267260 (page 3-4, FIG. 1-2)

  In the above technique, when the deceleration control is performed using the engine brake and the wheel brake, control is performed so that the operating ratio of the engine brake increases as the vehicle speed increases. Therefore, regardless of the expected traveling state after deceleration of the host vehicle, when the vehicle speed is decelerated from a high state, the engine brake operation ratio is always increased. However, when the engine is decelerated by the engine brake, the engine speed increases, so that a loud noise or vibration is generated from the engine. Therefore, when decelerating using the engine brake when finally decelerating to a speed close to the stop or stop state, such as when stopping at a temporary stop or red light, for example, the wheel will eventually become In spite of the deceleration by the brake, noise and vibration are generated unnecessarily, which may give the driver a sense of incongruity. Therefore, depending on the expected traveling state after deceleration of the host vehicle, it may be preferable from the viewpoint of noise and vibration to decelerate only with the wheel brake without using the engine brake.

  The present invention has been made in view of the above-described problems, and an object thereof is to give an uncomfortable feeling to the driver by appropriately determining a deceleration means according to an expected traveling state after deceleration of the host vehicle. It is another object of the present invention to provide a vehicle control apparatus and method that can perform control for decelerating the host vehicle.

  The characteristic configuration of the vehicle control device according to the present invention for achieving the above object includes position information acquisition means for acquiring position information of the own vehicle, and road information of the traveling direction of the own vehicle based on the position information. When the host vehicle needs to decelerate based on the road information acquiring unit, the vehicle speed information acquiring unit for acquiring information on the current vehicle speed of the host vehicle, and the road information and the current vehicle speed, a deceleration target The speed ratio of the speed change mechanism for performing appropriate deceleration by engine braking based on the deceleration target determination means for determining the point and the target vehicle speed, the current vehicle speed and the target vehicle speed, and the distance to the deceleration target point A speed ratio determining means for determining and a speed reduction control determining means for determining a speed reduction control type for decelerating the host vehicle, wherein the speed reduction control determining means is determined by the speed ratio determining means. When the traveling state quantity of the host vehicle when the vehicle is decelerated to the target vehicle speed at a determined gear ratio is greater than or equal to a predetermined state threshold value defined with reference to a lower limit value of the traveling state quantity at which the engine brake acts, The point is to decide to perform deceleration control using the brake.

  According to this characteristic configuration, the traveling state quantity of the host vehicle after deceleration at the transmission ratio determined by the transmission ratio determining means is a predetermined state threshold value determined based on the lower limit value of the traveling state quantity on which the engine brake acts. If it is less than that, the deceleration control using the engine brake is not performed. That is, when the vehicle is finally stopped or decelerated until the low-speed traveling state is less than a predetermined state threshold, deceleration without using the engine brake is performed by vehicle control or driver's operation. Therefore, it is possible to suppress the generation of unnecessary noise and vibration, and the host vehicle can be decelerated without causing the driver to feel uncomfortable.

More specifically, the travel state amount is set as a vehicle speed, and the deceleration control determining means uses the target vehicle speed as a reference based on the lower limit value of the vehicle speed at which the engine brake is applied for the speed ratio determined by the speed ratio determining means. When the vehicle speed is equal to or higher than the predetermined threshold vehicle speed determined as follows, it is preferable that the deceleration control using the engine brake is determined.
According to this configuration, the engine speed can be determined by comparing the target vehicle speed determined by the deceleration target determination means with a threshold vehicle speed as a state threshold predetermined for each gear ratio with reference to the lower limit value of the vehicle speed at which the engine brake acts. It can be determined whether or not to perform deceleration control using a brake.

Further, the travel state quantity is set as the engine speed, and the deceleration control determining means determines the engine speed when the engine speed is reduced to the target vehicle speed at the speed ratio determined by the speed ratio determining means. It is also suitable as a configuration for determining that the deceleration control using the engine brake is to be performed when the rotation speed is equal to or higher than a predetermined threshold rotation speed determined with the lower limit of the rotation speed as a reference.
If comprised in this way, the predetermined | prescribed state threshold value defined on the basis of the engine speed after deceleration to the target vehicle speed in the gear ratio determined by the gear ratio determination means, and the lower limit value of the engine speed at which the engine brake acts It is possible to determine whether or not the deceleration control using the engine brake is to be performed by comparing with the threshold rotational speed as.

  Here, the vehicle further includes reacceleration determining means for determining the possibility that the own vehicle will reaccelerate after passing the deceleration target point, and the deceleration control determining means is configured such that the running state amount of the own vehicle is applied by the engine brake. The engine brake is used when it is greater than or equal to a predetermined state threshold determined with reference to the lower limit value of the running state amount to be determined and there is a possibility of reacceleration by the reacceleration determination means. It is preferable to adopt a configuration that determines to perform deceleration control.

  If comprised in this way, when there exists a possibility of accelerating again after deceleration, the deceleration control using an engine brake will be performed. For this reason, at the time of reacceleration after deceleration, the transmission gear ratio is in a large state (a state on the low speed side), so that the acceleration response at the time of reacceleration can be improved. On the other hand, when the vehicle is finally stopped or decelerated until a low-speed traveling state less than a predetermined state threshold value is reached, deceleration without using an engine brake is performed by vehicle control or a driver's operation. Therefore, it is possible to suppress the generation of unnecessary noise and vibration, and the host vehicle can be decelerated without causing the driver to feel uncomfortable.

  The determination of the possibility that the own vehicle will be reaccelerated by the reacceleration determining means corresponds to, for example, one or more situation pattern information that defines a situation where the own vehicle needs to decelerate, and each situation pattern information. According to the information on the possibility of reacceleration specified in the above. Here, the information on the situation in which the host vehicle needs to decelerate is, for example, map information stored in a map database or the like, the host vehicle position and host vehicle direction information, imaging information from a vehicle-mounted camera, VICS (Vehicle Information and It can be acquired based on traffic information from Communication System: registered trademark, etc.).

  Further, the deceleration control determining means is a case where the host vehicle needs to decelerate, and the case where it is determined that the deceleration control using the engine brake is to be performed or the deceleration by only the engine brake is not sufficient. In one or both of the cases, it is preferable to adopt a configuration in which it is determined to perform deceleration control using a wheel brake.

  With this configuration, the host vehicle can be appropriately decelerated using the wheel brake even when deceleration control using the engine brake is not performed or when deceleration using only the engine brake is insufficient. Therefore, it is possible to suppress generation of noise and vibration in vain, and to perform deceleration control of the host vehicle without causing the driver to feel uncomfortable.

  Further, the deceleration control determining means is a case where the host vehicle needs to decelerate, and the case where it is determined that the deceleration control using the engine brake is to be performed or the deceleration by only the engine brake is not sufficient. In one or both cases, it is preferable to adopt a configuration in which it is determined to perform notification control that prompts the driver to decelerate.

  If comprised in this way, even when the deceleration control using an engine brake is not performed, or even when the deceleration only by an engine brake is not enough, a driver | operator can be operated to decelerate the own vehicle. Therefore, it is possible to suppress the generation of unnecessary noise and vibration, and the host vehicle can be decelerated without causing the driver to feel uncomfortable.

  The characteristic configuration of the vehicle according to the present invention is the vehicle control device having the above-described configuration, and when the deceleration control determination unit of the vehicle control device determines to perform the deceleration control using the engine brake, And a speed change mechanism that is controlled so as to be the speed change ratio determined by the speed change ratio determining means.

  According to this characteristic configuration, when it is determined that the vehicle control device having the above-described configuration performs the deceleration control using the engine brake, the gear ratio is appropriately changed and the deceleration control by the engine brake is executed. Can do. Therefore, it is possible to suppress the generation of unnecessary noise and vibration, and it is possible to realize a vehicle capable of appropriately performing deceleration control without causing the driver to feel uncomfortable.

  A characteristic configuration of the vehicle control method according to the present invention includes a position information acquisition step of acquiring position information of the own vehicle, and a road information acquisition step of acquiring road information of the traveling direction of the own vehicle based on the position information. A vehicle speed information acquisition step for acquiring information on the current vehicle speed of the host vehicle, and when the host vehicle needs to decelerate based on the road information and the current vehicle speed, a deceleration target point and a target vehicle speed are determined. A deceleration target determining step; and a gear ratio determining step for determining a gear ratio of a transmission mechanism for performing appropriate deceleration by engine braking based on the current vehicle speed, the target vehicle speed, and the distance to the deceleration target point; A deceleration control determining step for determining a deceleration control type for decelerating the host vehicle, wherein in the deceleration control determining step, the speed ratio determining step When the traveling state quantity of the host vehicle when the vehicle is decelerated to the target vehicle speed with the determined gear ratio is greater than or equal to a predetermined state threshold defined with reference to a lower limit value of the traveling state quantity on which the engine brake acts. In this respect, it is determined that the deceleration control using the engine brake is performed.

  According to this characteristic configuration, the predetermined state threshold value determined based on the lower limit value of the travel state amount at which the engine brake acts is determined by the travel state amount of the host vehicle after deceleration at the speed ratio determined in the speed ratio determination step. If it is less than that, the deceleration control using the engine brake is not performed. That is, when the vehicle is finally stopped or decelerated until the low-speed traveling state is less than a predetermined state threshold, deceleration without using the engine brake is performed by vehicle control or driver's operation. Therefore, it is possible to suppress the generation of unnecessary noise and vibration, and the host vehicle can be decelerated without causing the driver to feel uncomfortable.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram illustrating a configuration of a vehicle control device 1 according to the present embodiment. When it is determined that the host vehicle 2 needs to decelerate, the vehicle control device 1 determines an appropriate deceleration control type according to the expected traveling state after deceleration of the host vehicle 2 and decelerates the host vehicle 2. Control to make it happen. In the present embodiment, there are three types of specific deceleration control types: deceleration control using an engine brake, deceleration control using a wheel brake, and notification control that prompts the driver to decelerate. The vehicle control device 1 selects and executes one or more deceleration controls from these three types of deceleration control. In addition, the predicted traveling state after deceleration of the host vehicle 2 that is a determination material for determining the deceleration control type includes the vehicle speed as the traveling state quantity and the motion state of the host vehicle 2 (stopped state, slow traveling state, and restarting state). Acceleration state, etc.).

  Hereinafter, according to FIG. 1, the structure of each part of the vehicle control apparatus 1 which concerns on this embodiment is demonstrated. Note that each functional unit of the vehicle control device 1 includes a hardware or software (program) or a functional unit for performing various processes on input data with an arithmetic processing unit such as a CPU as a core member. Both are implemented and configured.

1. Around the Location Unit 4 The location unit 4 acquires information from the GPS receiver 5, the direction sensor 6, and the vehicle speed sensor 7. Here, the GPS receiver 5 is a device that receives a signal from a GPS satellite (not shown), and acquires various types of information such as the position (latitude and longitude) and the moving speed of the GPS receiver 5 based on the received signal. . The direction sensor 6 includes a geomagnetic sensor, a gyro sensor, an optical rotation sensor attached to the rotating part of the handle H, a rotary resistance volume, an angle sensor attached to the wheel part, and the like. Is detected. The vehicle speed sensor 7 includes a vehicle speed pulse sensor that detects the number of rotations of the wheel, a combination of a yaw / G sensor that detects the acceleration of the host vehicle, and a circuit that integrates the detected acceleration twice. The present vehicle speed Vp is detected.

  And the location part 4 performs the calculation which pinpoints the position and direction of the own vehicle by a well-known method based on the information acquired from these GPS receiver 5, the direction sensor 6, and the vehicle speed sensor 7. FIG. The position and direction of the host vehicle 3 specified by the location unit 4 are output to the road information acquisition unit 8, the deceleration target determination unit 9, and the gear ratio determination unit 10 as host vehicle position information and host vehicle direction information. The The vehicle speed information indicating the current vehicle speed Vp of the host vehicle 2 acquired by the vehicle speed sensor 7 is output to the deceleration target determination unit 9 and the gear ratio determination unit 10 in addition to the location unit 4. Therefore, in the present embodiment, the location unit 4 constitutes “position information acquisition means” in the present invention, and the vehicle speed sensor 7 constitutes “vehicle speed information acquisition means” in the present invention.

2. Map database DB
Map information including road information C is stored in the map database DB. FIG. 2 is an explanatory diagram showing the contents of the map information stored in the map database DB. As shown in this figure, here, a road network layer X1, a road information layer X2, and a feature layer X3 are stored as map information. This map database DB is a hard disk drive having a recording medium capable of storing information and its driving means, such as a hard disk drive, a DVD drive with a DVD-ROM, and a CD drive with a CD-ROM. It is provided as a wear configuration.

  The road network layer X1 is a layer indicating connection information between roads. Specifically, it has information on a large number of nodes N having position information on a map expressed by latitude and longitude, and information on a large number of links K that connect the two nodes N to form a road. It is configured. Each link K has information such as the type of road (type of highway, toll road, national road, prefectural road, etc.) and link length as the link information.

  The road information layer X2 is a layer that is stored in association with the road network layer X1 and shows detailed information on the road. Specifically, there are a large number of information on each node N associated with the road network layer X1, and position information on the map that is arranged between the two nodes N (on the link K) and expressed in latitude and longitude. The shape complementing point S is included. In the road information layer X2, various information such as road gradient information, width information, cant (bank) information, lane number information, and the like are stored in association with each node N and each shape complement point S. . In this application, in order to avoid complexity, both the node N and the shape complement point S are referred to as a node N. Unless otherwise specified, the node N includes the shape complement point S.

  The feature layer X3 is stored in association with the road network layer X1 and the road information layer X2, and shows information on various features such as paint display and three-dimensional objects provided on the road and its surroundings, and information on the background, etc. It is a layer. The paint display feature information Cc1 stored in the feature layer X3 includes stop lines, pedestrian crossings, lane markings (including information on types of lane markings such as solid lines, broken lines, and double lines), and each lane. A direction-by-direction traffic classification display for specifying the direction of travel, a speed display, and the like are included. The feature information Cc2 of the three-dimensional object includes traffic lights, various road signs, guardrails, buildings, utility poles, signboards, and the like.

3. Road information acquisition unit 8
As shown in FIG. 1, the road information acquisition unit 8 acquires own vehicle position information and own vehicle direction information output from the location unit 4, and road information C on the traveling direction of the own vehicle 2 based on these information. Is acquired from the map database DB. Specifically, the acquired road information C includes a road shape within a predetermined distance in the traveling direction of the host vehicle 2, feature information Cc of the feature existing on the road, and the like. Here, the road shape includes the arrangement of the node N representing the shape of the road center line, the presence or absence of an intersection, the number of lanes, the width, and the like. When the road information C is acquired, the road information acquisition unit 8 acquires road information C within a search range set in advance from the position indicated by the own vehicle position information toward the traveling direction of the own vehicle 2. Here, the search range is defined by the distance from the vehicle position, and the distance can be set to, for example, 100 [m] or 300 [m]. The road information C acquired by the road information acquisition unit 8 is output to the deceleration target determination unit 9 and the deceleration necessity determination unit 11. In the present embodiment, the road information acquisition unit 8 constitutes “road information acquisition means” in the present invention.

4). Deceleration target determination unit 9
When the host vehicle 2 needs to decelerate based on the road information C acquired by the road information acquisition unit 8 and the current vehicle speed Vp of the host vehicle 2 acquired by the vehicle speed sensor 7, the deceleration target determination unit 9 Then, the process of determining the deceleration target point Pt and the target vehicle speed Vt is performed. Here, the deceleration target point Pt is a target point when performing deceleration control of the host vehicle 2, and the target vehicle speed Vt is a target value of the vehicle speed at the deceleration target point Pt. In addition, the necessity determination of the deceleration of the own vehicle 2 is performed in the deceleration necessity determination part 11 mentioned later. In the present embodiment, the deceleration target determination unit 9 constitutes “deceleration target determination means” in the present invention.

  An example of a method for determining the deceleration target point Pt and the target vehicle speed Vt in the deceleration target determination unit 9 will be described. Here, as shown in FIG. 3, an example in which deceleration control is performed when the host vehicle 2 enters a curve will be described. FIG. 4 is a diagram illustrating a method of determining the deceleration target point Pt. As shown in this figure, when determining the deceleration target point Pt, first, the recommended vehicle speed vai (i is a natural number) at each node Ni (i is a natural number) included in the road information C within the search range is determined.

  Here, the recommended vehicle speed vai is a predetermined recommended lateral acceleration in which the turning lateral acceleration acting on the vehicle 2 is based on the shape of the road at each node Ni, specifically, the curvature radius of the road at a curve or a right-left turn intersection. The vehicle speed will be determined. Here, the recommended lateral acceleration is determined on the basis that the vehicle 2 can turn stably and does not give the driver unpleasant feeling, for example, 0.2 [G] (G is gravitational acceleration). It is preferable. FIG. 5 is a diagram showing a map representing the relationship between the curvature radius of the road and the recommended vehicle speed. In this map, a constant low vehicle speed is defined in a region where the curvature radius of the road is very small, and in other regions, the turning lateral acceleration is a recommended lateral acceleration (here, 0.2%) according to the curvature radius of the road. [G]) is defined. The recommended vehicle speed vai at each node Ni is determined according to the map shown in FIG. Here, the radius of curvature of the road at each node Ni is calculated by calculating a circle passing through the position of each node Ni and the position of the adjacent node N before and after the node Ni, and the radius of the circle is calculated as the radius of curvature of the road at each node Ni. Can be calculated.

Then, based on the current vehicle speed Vp of the host vehicle 2, the distance Li from the host vehicle position to each node Ni (i is a natural number), and the recommended vehicle speed vai at each node Ni, the necessary deceleration acceleration Gi ( i is a natural number). Specifically, as shown in FIG. 4, the necessary deceleration acceleration Gi required for decelerating from the actual vehicle speed V to the recommended vehicle speed vai at each node Ni during the distance Li from the own vehicle position to each node Ni. It calculates by following Formula (1).
Gi = (Vp ² −vai ² ) / (2 × Li) (1)
The distance Li from the vehicle position to each node Ni is based on the position information of each node N included in the road information C within the search range in the direction along the road from the vehicle position to each node Ni. It is obtained by calculating the distance (distance on the road).

  Then, the node Ni having the maximum value of the required deceleration acceleration Gi among the nodes Ni within the search range is determined as the deceleration target point Pt. In the example shown in FIG. 4, the change in the vehicle speed from the vehicle position to each of the nodes N1, N2, and N3 (see FIG. 3) is indicated by three deceleration acceleration curves. Here, each deceleration acceleration curve corresponds to the required deceleration acceleration G1, G2, and G3, and indicates that the greater the curvature of the deceleration acceleration curve, that is, the tighter the bending, the greater the required deceleration acceleration. Therefore, in the example shown in FIG. 4, the necessary deceleration acceleration G2 with respect to the node N2 is the maximum, and therefore the node N2 becomes the deceleration target point Pt. Further, the recommended vehicle speed vai at the deceleration target point Pt becomes the target vehicle speed Vt. Therefore, in the example shown in FIG. 4, the recommended vehicle speed va2 at the node N2 is the target vehicle speed Vt. In the example shown in FIG. 4, the calculation is performed only for the three nodes N1 to N3. However, in reality, a larger number of nodes Ni are often calculated.

5. Gear ratio determining unit 10
The gear ratio determination unit 10 is based on the current vehicle speed Vp and the target vehicle speed Vt determined by the deceleration target determination unit 9 and the distance from the vehicle position to the deceleration target point Pt determined by the deceleration target determination unit 9. Thus, a process for determining the gear ratio of the automatic transmission mechanism 2b for performing appropriate deceleration by the engine brake, that is, the control gear ratio Rt is performed. Here, the gear ratio determination unit 10 is connected to the output shaft rotational speed sensor 18. The output shaft rotational speed sensor 18 is a sensor that detects the rotational speed of the output shaft (the wheel W side shaft) of the automatic transmission mechanism 2b. Information detected by the output shaft rotational speed sensor 18 is output to the gear ratio determination unit 10. In this example, the output shaft rotational speed sensor 18 is configured differently from the vehicle speed sensor 7, but these may be the same sensor.

  The automatic transmission mechanism 2b has an input shaft connected to the engine 2c via a driving force transmission mechanism such as a torque converter or a clutch (not shown). The automatic transmission mechanism 2b has an output shaft connected to the wheel W via a differential gear or a drive shaft. In the present embodiment, a case where a stepped (five steps) automatic transmission is used as the automatic transmission mechanism 2b will be described as an example. The automatic transmission mechanism 2b is configured to automatically increase (shift down) the gear ratio when the engine 2c becomes equal to or less than the idling speed Ec.

  An example of a method for determining the gear ratio of the automatic transmission mechanism 2b in the gear ratio determining unit 10 will be described. First, the transmission ratio determination unit 10 determines the automatic transmission mechanism 2b from the current vehicle speed Vp and the necessary deceleration acceleration Gi (G2 in the example shown in FIG. 4) up to the deceleration target point Pt obtained by the deceleration target determination unit 9. A recommended input shaft rotational speed that is a recommended rotational speed of the input shaft (the shaft on the engine 2c side) is determined. FIG. 6 is a diagram showing a map for determining the recommended input shaft speed. In this map, the straight line γmax indicates the relationship between the input shaft speed of the automatic transmission mechanism 3 and the vehicle speed when the transmission gear ratio of the automatic transmission mechanism 3 is set to the maximum (when the transmission gear ratio is set to the lowest speed side). The straight line γmin indicates the relationship between the input shaft speed of the automatic transmission mechanism 3 and the vehicle speed when the transmission gear ratio of the automatic transmission mechanism 3 is set to the minimum (when the transmission gear ratio is set to the highest speed side). Line γ1 shows the relationship between the vehicle speed and the recommended input shaft speed when the required deceleration acceleration is 1 [G], and line γ2 shows the vehicle speed when the required deceleration acceleration is 0.2 [G]. And the recommended input shaft speed. When the required deceleration acceleration is between 0.2 [G] and 1 [G], a value between the line γ1 and the line γ2 is appropriately selected. Therefore, according to this map, the recommended input shaft speed according to the current vehicle speed Vp and the necessary deceleration acceleration Gi up to the deceleration target point Pt is determined. At this time, the recommended input shaft speed increases as the required deceleration acceleration increases. As the recommended input shaft speed increases, the gear ratio of the automatic transmission mechanism 3 increases as will be described later. In the map of FIG. 6, the numerical values shown as the vehicle speed on the horizontal axis and the recommended input shaft rotation speed on the vertical axis are examples, and can be changed as appropriate.

Then, the gear ratio determination unit 10 performs the actual output shaft rotation that is the recommended input shaft rotational speed determined as described above and the rotational speed of the output shaft of the automatic transmission mechanism 2 b detected by the output shaft rotational speed sensor 18. The recommended gear ratio is determined from the number. Specifically, it is calculated by the following equation (2).
(Recommended transmission ratio) = (Recommended input shaft speed) / (Actual output shaft speed) (2)
In the present embodiment, since a stepped (five-step) automatic transmission is used as the automatic transmission mechanism 2b, the transmission ratio determination unit 10 performs the transmission closest to the recommended transmission ratio obtained by the above equation (2). A gear having a ratio is selected, and the gear ratio set for the gear is determined as the control gear ratio Rt of the automatic transmission mechanism 2b. In the present embodiment, the reduction gear ratio determination unit 10 constitutes “transmission ratio determination means” in the present invention.

6). Deceleration necessity determination unit 11
The deceleration necessity determination unit 11 performs a process of determining whether the host vehicle 2 needs to decelerate. Here, the deceleration necessity determination unit 11 includes a reacceleration determination unit 12. The reacceleration determination unit 12 performs a process of determining the possibility that the host vehicle 2 will reaccelerate after passing through the deceleration target point Pt. In the present embodiment, the determination of the necessity of deceleration by the deceleration necessity determination unit 11 and the determination of the possibility of reacceleration by the reacceleration determination unit 12 are the road information C of the traveling direction of the host vehicle 2 and the imaging device 13. Various information related to the situation of the vehicle 2 such as the surrounding situation of the own vehicle 2 indicated in the image recognition result using VICS, traffic information from the VICS, etc., the state of the turn signal 2d and the guidance route of the navigation device, etc. This is performed by applying the situation pattern information defined in the pattern table Tb. Here, the reacceleration determining unit 12 constitutes “reacceleration determining means” in the present invention. This will be specifically described below.

The deceleration necessity determination unit 11 is connected to the image recognition unit 14 and the VICS receiver 15. The image recognition unit 14 is connected to the imaging device 13 and is configured to receive imaging information. The imaging device 13 is configured by an in-vehicle camera mounted on the host vehicle 2. Here, the imaging device 13 is disposed toward the front of the host vehicle 2 and is provided so that the road in the traveling direction of the host vehicle 2 and its surroundings are photographed. The image recognition unit 14 performs image recognition processing on imaging information output from the imaging device. Specifically, in this image recognition processing, in the traveling direction of the host vehicle 2, the presence / absence of a traffic light, the state of a signal such as a red signal or a green signal, paint display on the road, road signs, road shape, driving during driving Recognize lanes. This image recognition processing is performed using a known method such as pattern matching.
The VICS receiver 9 is a device that receives a signal transmitted from a signal transmitter installed at a predetermined point on the road, and receives a VICS optical beacon and radio wave beacon, or a VICS signal multiplexed in FM broadcasting. It is a device that can do. The deceleration necessity determination unit 11 can acquire various types of traffic information such as traffic jam information, construction information, and accident information using the VICS signal.
The deceleration necessity determination unit 11 is configured to receive road information C in the traveling direction of the host vehicle 2 acquired by the road information acquisition unit 8.

  The situation pattern table Tb includes one or more situation pattern information that defines a situation in which the host vehicle 2 needs to decelerate, and information on the possibility of reacceleration that is defined corresponding to each situation pattern information. It is a table defined in association. FIG. 7 is a diagram showing a specific example of the situation pattern table Tb. As shown in this figure, the situation pattern information is obtained from “road information” obtained from the road information C in the traveling direction of the host vehicle 2 obtained by the road information obtaining unit 8 and the image recognition result obtained by the image recognition unit 14. "Image recognition information", "traffic information" obtained from the VICS signal received by the VICS receiver 9, "other information" obtained from the turn signal 2d of the host vehicle 2, guidance route information of a navigation device (not shown), etc. It consists of a plurality of situation patterns that combine one or more pieces of information. In addition, information on the possibility of reacceleration is given to each situation pattern.

  In this situation pattern table Tb, only patterns that require the host vehicle 2 to decelerate are defined. Therefore, the deceleration necessity determination unit 11 determines that the host vehicle 2 needs to be decelerated when the situation pattern defined in the situation pattern table Tb is applicable, and if not, the own vehicle 2 2 can be determined that there is no need to decelerate.

  Further, the reacceleration determining unit 12 determines whether or not the re-acceleration associated with the situation pattern is in accordance with which situation pattern specified in the situation pattern table Tb is the current surrounding situation of the host vehicle 2. The possibility of reacceleration after passing through the deceleration target point Pt is determined according to the information on the possibility of existence. For example, the situation patterns (1) to (5) shown in FIG. 7 are given information that the possibility of re-acceleration is “Yes”, and the situation patterns (6) to (9) have the possibility of re-acceleration “ Information “nothing” is given. Therefore, when the current surrounding situation of the host vehicle 2 is applicable to the situation pattern (2), for example, it is determined that the possibility of re-acceleration is “present”.

  Each situation pattern (1)-(9) shown in FIG. 7 is demonstrated. The situation pattern (1) is a case where the road shape obtained from the road information C in the traveling direction of the host vehicle 2 is “curve”. In this case, it is highly likely that the host vehicle 2 decelerates and enters the curve, and then accelerates again after passing the curve. In the situation pattern (2), the road shape obtained from the road information C in the traveling direction of the host vehicle 2 is “intersection (crossroad)”, the signal state obtained from the image recognition result is “green light”, and the turn When the signal 2d is in a blinking state and a guidance route is set, the route indicates a right turn or a left turn. In this case, the host vehicle 2 decelerates when entering the intersection, and is likely to accelerate again after changing course (turning right or left) at the intersection. In the situation pattern (3), the road shape obtained from the road information C in the traveling direction of the host vehicle 2 is “intersection (T-junction)”, and the signal state obtained from the image recognition result is “green light” It is. In this case, the host vehicle 2 decelerates when entering the intersection, and is likely to accelerate again after changing course (turning right or left) at the intersection. The situation pattern (4) is a case where the road shape obtained from the road information C in the traveling direction of the host vehicle 2 is “width reduction”. In this case, the host vehicle 2 is likely to accelerate again after entering the road where the width of the host vehicle 2 is decreasing and the width is decreasing. The situation pattern (5) is a case where it is found from the image recognition result that an obstacle exists in the traveling direction of the host vehicle 2. Here, the obstacle includes, for example, a vehicle parked on the road, a fallen object on the road, a pedestrian, and the like. In this case, the host vehicle 2 is likely to accelerate again after decelerating to avoid an obstacle. Therefore, these situation patterns (1) to (5) stipulate that the necessity of deceleration is “present” and the possibility of reacceleration is also “present”.

  The situation pattern (6) is a case where the state of the signal obtained from the image recognition result is “red signal”. In the situation pattern (7), when feature information Cc representing “pause” such as a stop sign or a road paint on a stop line is obtained as a feature existing on the road in the traveling direction of the host vehicle 2. It is. In these cases, the host vehicle 2 is likely to stop after decelerating, and is unlikely to be accelerated again. The situation pattern (8) is a case where traffic information indicating “congestion” is obtained from the VICS signal received by the VICS receiver 9. The situation pattern (9) is a case where traffic information indicating “development of construction” is obtained from the VICS signal received by the VICS receiver 9. In these cases, the host vehicle 2 is likely to travel at a slow speed over a certain distance after being decelerated, and is less likely to be accelerated again. Therefore, in these situation patterns (6) to (9), the necessity of deceleration is defined as “present”, and the possibility of reacceleration is defined as “none”.

The situation patterns (1) to (9) defined in the situation pattern table Tb are merely examples, and more situation patterns are defined and stored in the actual situation pattern table Tb. In addition, image recognition information may be used supplementarily for recognizing road information such as curves and intersections, and for recognizing traffic information such as traffic congestion and construction slowdown. In addition, about the operation | movement of deceleration and reacceleration of the own vehicle 2 when it corresponds to each situation pattern prescribed | regulated to these, although the operation | movement of possibility is prescribed | regulated, actual operation | movement of the own vehicle 2 is a situation pattern table. Naturally, it may be different from that defined for Tb.
Information on the determination result regarding the necessity of deceleration and the possibility of reacceleration by the deceleration necessity determination unit 11 including the reacceleration determination unit 12 is output to the deceleration control determination unit 16.

7). Deceleration control determination unit 16
The deceleration control determination unit 16 performs a process of determining a deceleration control type for decelerating the host vehicle 2. In the present embodiment, the deceleration control determination unit 16 is configured to select one of two types of engine brake and hall brake as the deceleration control type. Then, the deceleration control determining unit 16 determines that the target vehicle speed Vt determined by the deceleration target determining unit 9 is the lower limit value of the vehicle speed at which the engine brake acts on the control gear ratio Rt determined by the gear ratio determining unit 10. When the vehicle speed is equal to or higher than a predetermined threshold vehicle speed Vs set as a reference, and 2) when the reacceleration determination unit 12 determines that there is a possibility of reacceleration, it is determined to perform deceleration control by engine braking. . In this example, the threshold vehicle speed Vs is set to a speed that matches the lower limit value of the vehicle speed at which the engine brake acts on the control speed ratio Rt determined by the speed ratio determining unit 10. In the present embodiment, the deceleration control determination unit 16 constitutes “deceleration control determination means” in the present invention.

  First, the predetermined vehicle speed Vt determined by the above-described 1) deceleration target determination unit 9 is determined based on the lower limit value of the vehicle speed at which the engine brake acts on the control gear ratio Rt determined by the gear ratio determination unit 10. The condition when the vehicle speed is equal to or higher than the threshold vehicle speed Vs will be described. In this example, the threshold vehicle speed Vs is set to a speed that matches the lower limit value of the vehicle speed at which the engine brake acts. FIG. 8 is a graph showing a method for determining the threshold vehicle speed Vs. This graph shows the relationship between the vehicle speed and the engine speed for each of a plurality of shift speeds (1st to 5th). These relationships are represented by straight lines. In this example, the automatic transmission mechanism 2b is provided with five shift stages from 1st to 5th. In this graph, the engine idling speed Ec is indicated by a broken line.

  The engine 2c is set so as not to be equal to or less than the idling rotational speed Ec in a no-load state. Therefore, when the engine rotational speed is less than the idling rotational speed Ec, the wheel W is driven by the engine 2c that attempts to maintain the idling rotational speed Ec, and the engine brake does not act. That is, the lower limit value of the engine speed at which the engine brake acts is equal to the idling speed Ec, which is the engine speed at which the engine braking force becomes zero. Therefore, as shown in FIG. 8, the lower limit value of the vehicle speed at which the engine brake acts corresponds to the vehicle speeds Vc1 to Vc5 of the first to fifth gears at the idling speed Ec. In this example, the threshold vehicle speed Vs is a lower limit value Vc1 to Vc5 of the vehicle speed at which the engine brake acts. That is, the threshold vehicle speed Vs for the control gear ratio Rt determined by the gear ratio determination unit 10 is the vehicle speed Vci (i = 1 to 5) of any gear stage having the control gear ratio Rt. For example, when the gear stage having the control gear ratio Rt is the third speed, the threshold vehicle speed Vs is Vc3 in FIG.

  The deceleration control determining unit 16 decelerates by engine braking when the condition of the above 1) is satisfied and 2) the reacceleration determining unit 12 determines that there is a possibility of reacceleration as described above. Decide to control. On the other hand, the deceleration control determination unit 16 performs the deceleration control by the wheel brake in cases other than when it is determined that the deceleration control using the engine brake is performed, that is, when the conditions 1) and 2) are not satisfied. Decide what to do. The content determined by the deceleration control determination unit 16 is output to the control unit 17 and executed.

8). Control unit 17
The control unit 17 performs deceleration control of the host vehicle 2 in accordance with the content of the deceleration control determined by the deceleration control determination unit 16. In this embodiment, deceleration control is performed by either engine braking or wheel braking. The deceleration control by the wheel brake is performed by controlling the operation of the brake actuator 2 a provided on the wheel of the host vehicle 2 by the control unit 17. This deceleration control is performed so as to approach the target vehicle speed Vt at the deceleration target point Pt determined by the deceleration target determination unit 9. The deceleration control by the engine brake is performed by controlling the operations of the transmission 2b and the engine 2c by the control unit 17. Specifically, control is performed to turn off the throttle of the engine 2c and change the transmission gear ratio of the transmission 2b to the control gear ratio Rt determined by the gear ratio determination unit 10.

9. Vehicle Control Method Next, a vehicle control method by the vehicle control device 1 according to the present embodiment will be described in detail based on the flowchart shown in FIG. First, the vehicle control device 1 acquires the vehicle position information and the vehicle direction information from the location unit 4 (step # 01). Next, the road information acquisition unit 8 acquires road information C in the traveling direction of the host vehicle 2 from the map database DB (step # 02). In this example, as the road information C, the road shape within the search range set in advance from the current position of the host vehicle 2 in the traveling direction, the feature information Cc of the feature existing on the road, and the like are acquired. In addition, the image recognition result by the image recognition unit 14 using the imaging device 13, the surrounding situation of the host vehicle 2 indicated by the traffic information acquired by the VICS receiver 15, the state of the turn signal 2 d, and guidance of a navigation device (not shown) Various information related to the state of the host vehicle 2 such as the route is acquired (step # 03).

  Next, the deceleration necessity determination unit 11 including the reacceleration determination unit 12 determines whether the host vehicle 2 needs to be decelerated and whether there is a possibility of reacceleration (step # 04). Then, when there is no need for deceleration (step # 05: NO), the process ends. If there is a need for deceleration (step # 05: YES), the deceleration target determination unit 9 determines the deceleration target point Pt and the target vehicle speed Vt (step # 06). The deceleration target point Pt and the target vehicle speed Vt are determined based on the road information C acquired by the road information acquisition unit 8 and the current vehicle speed Vp of the host vehicle 2 acquired by the vehicle speed sensor 7 as described above. Next, the transmission gear ratio determination unit 10 determines the control transmission gear ratio Rt of the automatic transmission mechanism 2b for performing appropriate deceleration by engine braking (step # 07). As described above, the control gear ratio Rt is determined based on the current vehicle speed Vp and the target vehicle speed Vt determined by the deceleration target determination unit 9 and the vehicle position up to the deceleration target point Pt determined by the deceleration target determination unit 9. And based on the distance from.

  Then, the deceleration control determining unit 16 determines a deceleration control type for decelerating the host vehicle 2. That is, the deceleration control determination unit 16 determines whether the vehicle speed is reduced by engine braking depending on whether 1) the target vehicle speed Vt is equal to or higher than the threshold vehicle speed Vs and 2) the reacceleration determination unit 12 determines that there is a possibility of reacceleration. Select control or deceleration control by wheel brake. These conditions 1) and 2) are as already described. If both conditions 1) and 2) are satisfied (step # 08: YES), the deceleration control determination unit 16 determines to perform deceleration control by engine braking (step # 09). Then, the control unit 17 controls the operations of the transmission 2b and the engine 2c, and executes deceleration control by engine braking (step # 10). On the other hand, when either one of the conditions 1) and 2) is not satisfied (step # 08: NO), the deceleration control determination unit 16 determines to perform the deceleration control by the wheel brake (step # 11). Then, the controller 17 controls the operation of the brake actuator 2a, and executes deceleration control by wheel brake (step # 12). The process ends here.

[Other Embodiments]
(1) In the above embodiment, the deceleration control determining unit 16 uses the engine brake when 1) the target vehicle speed Vt is equal to or higher than the predetermined threshold vehicle speed Vs, and 2) when it is determined that the possibility of reacceleration is high. The example of determining to perform the deceleration control that has been described has been described. However, the application range of the present invention is not limited to this configuration. That is, the deceleration control determining unit 16 does not consider the condition 2) above, and the target vehicle speed Vt is based on the lower limit value of the vehicle speed at which the engine brake acts on the control gear ratio Rt determined by the gear ratio determining unit 10. In another preferred embodiment, it is determined that the deceleration control using the engine brake is performed when the vehicle speed is equal to or higher than a predetermined threshold vehicle speed Vs determined as follows.

(2) In the above embodiment, the case where the threshold vehicle speed Vs is set to a speed that matches the lower limit values Vc1 to Vc5 of the vehicle speed at which the engine brake acts has been described. However, the threshold vehicle speed Vs in the present invention is not limited to such a value. That is, when the threshold vehicle speed Vs is set to a speed that matches the vehicle speed lower limit values Vc1 to Vc5 at which the engine brake acts, the braking force becomes small at the end of the deceleration control by the engine brake. Therefore, the threshold vehicle speed Vs is set to a vehicle speed that is higher by a predetermined amount than the lower limit values Vc1 to Vc5 of the vehicle speed at which the engine brake acts in order to ensure the braking force by the engine brake even in the final stage of the deceleration control. It is also suitable as a configuration. The predetermined amount at this time is preferably determined so as to be a vehicle speed at which an engine brake is applied so that the driver of the host vehicle 2 can experience deceleration acceleration. Even when the threshold vehicle speed Vs is set to a speed that matches the lower limit value of the vehicle speed at which the engine brake acts, at the time of reacceleration after deceleration, the speed ratio of the transmission is large (low speed state). Therefore, there is an advantage that the responsiveness of acceleration at the time of reacceleration can be improved.

(3) Further, in the above-described embodiment, the deceleration control determination unit 16 determines the vehicle speed at which the engine brake acts on the control gear ratio Rt determined by the gear ratio determination unit 10 with respect to the condition 1). The case has been described in which it is determined that the deceleration control using the engine brake is performed when the vehicle speed is equal to or higher than a predetermined threshold vehicle speed Vs determined with reference to the lower limit value. However, the condition of 1) is not limited to this, and the engine brake is applied to the running state amount of the host vehicle 2 when the vehicle is decelerated to the target vehicle speed Vt at the control speed ratio Rt determined by the speed ratio determining unit 10. A configuration may be adopted in which deceleration control using engine braking is determined when the value is equal to or greater than a predetermined state threshold value determined based on the lower limit value of the travel state amount. Therefore, for example, when the amount of running state is the engine speed, as shown in FIG. 10, at the time of deceleration that is the engine speed when decelerating to the target vehicle speed Vt at the control speed ratio Rt determined by the speed ratio determining unit 10. When the engine speed Ed is equal to or higher than a predetermined threshold speed Es determined with reference to the lower limit value of the engine speed at which the engine brake acts, the deceleration control using the engine brake is determined. This is also a preferred embodiment. The example shown in FIG. 10 is a case where the gear stage having the control gear ratio Rt is the third speed. The threshold rotational speed Es is set to a rotational speed that matches the idling rotational speed Ec, which is the lower limit value of the engine rotational speed at which the engine brake acts. The threshold rotational speed Es is set to a rotational speed that is higher by a predetermined amount than the lower limit value of the engine rotational speed at which the engine brake acts in order to ensure the braking force by the engine brake even in the final stage of the deceleration control. You can also It is preferable that the predetermined amount at this time is determined so that the engine speed is such that the engine brake is applied to such an extent that the driver of the host vehicle 2 can experience the deceleration acceleration as described in the above (2). .

(4) In the above embodiment, the case where a stepped automatic transmission is used as the automatic transmission mechanism 2b has been described. However, it is also a preferred embodiment to use a continuously variable transmission mechanism as the automatic transmission mechanism 2b. As this continuously variable transmission mechanism, for example, a belt type CVT (Continuously Variable Transmission), a toroidal type CVT, or the like is used. When such a continuously variable transmission mechanism is used, it is preferable that the transmission ratio determination unit 10 determines the recommended transmission ratio obtained by the above equation (2) as the control transmission ratio Rt of the automatic transmission mechanism 2b.

(5) In the above embodiment, the case where the deceleration control determination unit 16 is configured to select one of two types of engine brake and hall brake as the deceleration control type has been described. However, the scope of application of the present invention is not limited to this. That is, when the deceleration control determining unit 16 determines to perform the deceleration control using the engine brake, if the deceleration using only the engine brake is not sufficient, the deceleration control using the wheel brake is used together. This is also a preferred embodiment. Further, it is also preferable that the deceleration control determination unit 16 is configured to determine to perform notification control (one of the deceleration control types) that prompts the driver to decelerate instead of the deceleration control using the wheel brake. One of the forms. This is a control that causes the driver to operate the brake pedal to perform deceleration using the wheel brake, instead of directly controlling the wheel brake by the vehicle control device 1. In this case, specifically, the notification control can be performed by displaying a message on the monitor 19 shown in FIG. 1 or outputting a voice message, a warning sound, or the like using the speaker 20.

  According to the present invention, it is possible to perform vehicle control for decelerating the host vehicle by an appropriate deceleration method according to the situation, and therefore it can be suitably used as a vehicle control device mounted on various vehicles.

The block diagram which shows the structure of the vehicle control apparatus which concerns on embodiment of this invention. Explanatory diagram showing the contents of the map information stored in the map database The figure which shows the state when the own vehicle enters the curve Diagram for explaining how to determine the deceleration target point A diagram showing a map showing the relationship between the radius of curvature of the road and the recommended vehicle speed Diagram showing the map for determining the recommended input shaft speed The figure which shows the specific example of a situation pattern table Graph for explaining how to determine threshold vehicle speed The flowchart which shows the vehicle control method which concerns on embodiment of this invention. The graph for demonstrating the determination method of whether to perform the deceleration control using the engine brake which concerns on other embodiment of this invention.

Explanation of symbols

1: Vehicle control device 2: Host vehicle 4: Location part (position information acquisition means)
7: Vehicle speed sensor (vehicle speed information acquisition means)
8: Road information acquisition unit (road information acquisition means)
9: Deceleration target determination unit (deceleration target determination means)
10: Transmission ratio determining unit (transmission ratio determining means)
11: Deceleration necessity determination unit 12: Reacceleration determination unit (reacceleration determination unit)
16: Deceleration control determination unit (deceleration control determination means)
17: Control unit C: Road information Tb: Situation pattern table Vp: Current vehicle speed Pt: Deceleration target point Vt: Target vehicle speed Rt: Control gear ratio Vs: Threshold vehicle speed Es: Threshold rotation speed

Claims (9)

Position information acquisition means for acquiring position information of the own vehicle;
Road information acquisition means for acquiring road information of the traveling direction of the host vehicle based on the position information;
Vehicle speed information acquisition means for acquiring current vehicle speed information of the host vehicle;
A deceleration target determining means for determining a deceleration target point and a target vehicle speed when the host vehicle needs to decelerate based on the road information and the current vehicle speed;
A gear ratio determining means for determining a gear ratio of a speed change mechanism for performing appropriate deceleration by engine braking based on the current vehicle speed and the target vehicle speed and a distance to the deceleration target point;
A deceleration control determining means for determining a deceleration control type for decelerating the host vehicle,
The deceleration control determining means is configured such that the traveling state quantity of the host vehicle when the vehicle is decelerated to the target vehicle speed at the transmission ratio determined by the transmission ratio determining means is based on the lower limit value of the traveling state quantity on which the engine brake acts. The vehicle control apparatus which determines performing deceleration control using an engine brake, when it is more than the predetermined state threshold defined as follows.   The travel state quantity is a vehicle speed, and the deceleration control determining means is a predetermined speed determined based on a lower limit value of a vehicle speed at which the engine brake is applied with respect to the speed ratio determined by the speed ratio determining means. The vehicle control device according to claim 1, wherein when it is equal to or higher than a threshold vehicle speed, it is determined to perform deceleration control using an engine brake.   The travel state quantity is an engine speed, and the deceleration control determining means determines that the engine speed when the engine speed is reduced to the target vehicle speed at the speed ratio determined by the speed ratio determining means is the engine speed at which an engine brake acts. 2. The vehicle control device according to claim 1, wherein the vehicle control device determines to perform deceleration control using an engine brake when the number of rotations is equal to or greater than a predetermined threshold rotational speed determined based on a lower limit value of the number. Re-acceleration determination means for determining the possibility that the host vehicle will re-accelerate after passing the deceleration target point;
The deceleration control determining means is a case where the running state amount of the host vehicle is equal to or greater than a predetermined state threshold value determined with reference to a lower limit value of the running state amount to which engine braking is applied, and the reacceleration determination The vehicle control device according to any one of claims 1 to 3, wherein when it is determined that there is a possibility of reacceleration by means, it is determined to perform deceleration control using an engine brake.   The reacceleration determining means includes one or more situation pattern information that defines a situation in which the host vehicle needs to decelerate, and information on the possibility of reacceleration defined in correspondence with each situation pattern information; The vehicle control device according to claim 4, wherein the possibility of the host vehicle reaccelerating is determined according to   The deceleration control determining means is a case where the host vehicle needs to decelerate, and a case other than when it is determined to perform deceleration control using an engine brake or when deceleration using only the engine brake is insufficient. The vehicle control device according to any one of claims 1 to 5, wherein one or both of them determines to perform deceleration control using a wheel brake.   The deceleration control determining means is a case where the host vehicle needs to decelerate, and a case other than when it is determined to perform deceleration control using an engine brake or when deceleration using only the engine brake is insufficient. The vehicle control device according to any one of claims 1 to 5, wherein one or both of them decides to perform notification control that prompts the driver to decelerate.   The gear ratio determination when the vehicle control device according to any one of claims 1 to 7 and the deceleration control determination means of the vehicle control device determine to perform deceleration control using an engine brake. And a speed change mechanism that is controlled to achieve a speed change ratio determined by the means. A location information acquisition step for acquiring location information of the host vehicle;
A road information acquisition step for acquiring road information in the traveling direction of the host vehicle based on the position information;
Vehicle speed information obtaining step for obtaining information on the current vehicle speed of the host vehicle;
A deceleration target determining step for determining a deceleration target point and a target vehicle speed when the host vehicle needs to decelerate based on the road information and the current vehicle speed;
A speed ratio determining step for determining a speed ratio of a speed change mechanism for performing appropriate deceleration by engine braking, based on the current vehicle speed and the target vehicle speed, and a distance to the deceleration target point;
A deceleration control determination step for determining a deceleration control type for decelerating the host vehicle,
In the deceleration control determination step, the traveling state amount of the host vehicle when the vehicle is decelerated to the target vehicle speed at the transmission ratio determined in the transmission ratio determination step is based on a lower limit value of the traveling state amount on which the engine brake acts. A vehicle control method for determining that deceleration control using an engine brake is to be performed when a predetermined state threshold value determined as follows is exceeded.

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