JP5692124B2 - Vehicle speed control system, vehicle speed control method, and vehicle speed control program - Google Patents

Description

  The present invention relates to a vehicle speed control system, a vehicle speed control method, and a vehicle speed control program.

  Conventionally, navigation cooperative control in which a vehicle navigation device and an ECU (Engine Control Unit) cooperate to control the speed of the vehicle has been performed. In the navigation cooperative control, a control target point is set ahead in the traveling direction of the vehicle based on the current position of the vehicle acquired by the navigation device and the map information stored in advance in the database of the navigation device. Then, based on the set control target point and the traveling state of the vehicle, the ECU automatically controls the vehicle speed so that the vehicle speed at the set control target point becomes a predetermined speed.

  In order to perform such navigation cooperative control accurately, it is necessary to accurately specify the travel route of the vehicle. The specification of the travel route is not a problem when the travel route is preset in the navigation device by the driver. However, when the travel route is not preset by the driver, the travel route is determined by the navigation device. Therefore, it is necessary to specify the control target point by predicting. For example, there is a case where a branch point exists in front of the traveling direction of the vehicle, and there are cases where a candidate for a control target point exists on each of a plurality of branch roads that branch from the branch point. In such a case, when it is necessary to start the navigation cooperative control for the candidates for the plurality of control target points before the vehicle reaches the branch point, the navigation cooperative control is performed before the vehicle reaches the branch point. It is necessary to narrow down candidates for the control target point by predicting which of the plurality of branch roads the vehicle will travel.

  For this reason, a technique for predicting which of a plurality of branch roads the vehicle travels has been proposed. For example, Patent Document 1 discloses a technique for storing traffic history information indicating a route traveled by a vehicle and determining priorities for a plurality of branch roads that branch at a branch point based on the traffic history information. Has been.

JP 2009-288251 A

  However, in the above conventional technique, the vehicle does not always travel on a branch road that has been passed in the past. Therefore, when the vehicle travels on a branch road that is different from the branch road predicted based on the traffic history information. There was a possibility that the navigation cooperation control could not be performed accurately because the prediction was wrong.

  The present invention has been made in view of the above, and in the case where a candidate for a control target point exists on each of a plurality of branch roads that branch from the branch point, which of the plurality of branch roads the vehicle travels on An object of the present invention is to provide a vehicle speed control system, a vehicle speed control method, and a vehicle speed control program that can accurately control the speed of the vehicle even when the vehicle speed cannot be predicted.

  In order to solve the above-described problems and achieve the object, the vehicle speed control system according to claim 1 includes map information storage means for storing map information, and current position acquisition means for acquiring the current position of the vehicle. A control target point that can be a target point for speed control of the vehicle based on the map information stored in the map information storage unit and the current position of the vehicle acquired by the current position acquisition unit Is a control target point determination means for determining whether or not there are at least two or more branch roads among a plurality of branch roads branching from a branch point existing forward in the traveling direction on the traveling road of the vehicle; , When it is determined by the control target point determination means that the control target point is present in each of the two or more branch paths, the control target point Control start point specification that specifies a control start point when the vehicle is speed-controlled at a predetermined first reference acceleration / deceleration until reaching the control target point so that the vehicle speed at the time of arrival reaches a predetermined speed And a fixed point specifying means for specifying a fixed point that is a point that exists in each of the two or more branch roads and that can determine the current position of the vehicle after passing through the branch point And, based on the control start point specified by the control start point specifying unit and the fixed point specified by the fixed point specifying unit, the control target points existing in the two or more branch paths The passage control means for determining whether there is a control target point in time even if the speed control is started after passing through the fixed point, and the control existing in the two or more branch paths From among the elephant points, exclude the control target points that are determined to be in time even if the speed control is started after passing through the fixed point by the passage permission determination unit, and until the vehicle reaches the branch point And a speed control means for controlling the speed.

  The vehicle speed control system according to claim 2 is the vehicle speed control system according to claim 1, wherein the map information storage means stores the map information including a branch angle of the branch road, The fixed point specifying unit specifies the fixed point based on a branch angle of the branch path included in the map information stored in the map information storage unit.

  According to a third aspect of the present invention, there is provided a vehicle speed control method comprising: a map information storing step for storing map information in a map information storing means; a current position acquiring step for acquiring a current position of the vehicle; and the map information storing step. Based on the stored map information and the current position of the vehicle acquired in the current position acquisition step, a control target point that can be a target point for speed control of the vehicle is advancing on the traveling road of the vehicle. A control target point determination step for determining whether or not each of at least two or more branch paths out of a plurality of branch paths branching from a branch point existing in the forward direction, and the control target point determination step When it is determined that a point to be controlled exists on each of the two or more branch paths, the control is performed for each of the points to be controlled. Control for specifying a control start point when speed-controlling the vehicle at a predetermined first reference acceleration / deceleration before reaching the control target point so that the speed of the vehicle at the time of reaching the elephant point becomes a predetermined speed A start point identifying step and a confirmation that identifies a confirmed point that is a point that exists in each of the two or more branch paths and that allows the current position of the vehicle to be determined after passing through the branch point The control target point existing in the two or more branch paths based on the point specifying step, the control start point specified in the control start point specifying step, and the fixed point specified in the fixed point specifying step A pass permission determination step for determining whether or not there is a control target point that is in time even if the speed control is started after passing the fixed point; From among the control target points existing on two or more branch paths, exclude the control target points that are determined to be in time even if the speed control is started after passing through the fixed point in the passability determination step. And a speed control step for controlling the speed of the vehicle before reaching the branch point.

  A vehicle speed control program according to claim 4 is a vehicle speed control program for causing a computer to execute the method according to claim 3.

  According to the vehicle speed control system according to claim 1, the vehicle speed control method according to claim 3, and the vehicle speed control program according to claim 4, based on the control start point and the confirmed point. It is determined whether or not there is a control target point that is in time even if the speed control is started after passing through the fixed point among the control target points existing on two or more branch paths. Since the speed control is performed before the vehicle reaches the branch point by excluding the control target point determined to be in time even if the speed control is started after passing the fixed point from the inside, a plurality of branches from the branch point Even when a candidate point to be controlled is set on each of the branch roads, and the vehicle is not predicted which of the plurality of branch roads is to be predicted, the vehicle speed control is performed accurately. Is possible.

  According to the vehicle speed control system of the second aspect, the fixed point is specified based on the branch angle of the branch path included in the map information, so that it is determined by considering the difference in the branch angle of the branch path. The point can be specified accurately.

1 is a block diagram illustrating a vehicle speed control system according to an embodiment of the present invention. It is a flowchart of a speed control process. It is explanatory drawing which illustrates the relationship between a branch point and a control object point. It is a flowchart of a control object point selection determination process. It is a figure which shows the relationship between the distance regarding speed control, and speed. It is explanatory drawing explaining the concept which specifies the coordinate of a fixed point. It is a flowchart of a fixed point specific process. It is a flowchart of the speed control process classified by control area.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a vehicle speed control system, a vehicle speed control method, and a vehicle speed control program according to the present invention will be described in detail with reference to the drawings. However, the present invention is not limited by this embodiment.

(Constitution)
First, the configuration of the vehicle speed control system according to the present embodiment will be described. FIG. 1 is a block diagram illustrating a vehicle speed control system according to the present embodiment. As shown in FIG. 1, the vehicle speed control system is attached to a vehicle (hereinafter, the host vehicle) and includes a navigation system 1 and an ECU 2. Further, the speed control system receives information on whether or not the vehicle brake is turned off via the ECU 2 or other known devices.

(Configuration-Navigation system)
The navigation system 1 is a system that performs navigation such as travel route guidance for the host vehicle, and includes a current position acquisition unit 10, a touch panel 20, a display 30, a speaker 40, and a navigation device 50.

(Configuration-Navigation system-Current position acquisition unit)
The current position acquisition unit 10 is a current position acquisition unit that acquires the current position of the host vehicle. Specifically, the current position acquisition unit 10 includes at least one of a GPS, a geomagnetic sensor, a distance sensor, and a gyro sensor (all of which are not shown), and displays the current position (coordinates) and direction of the host vehicle. Detection is performed by a known method.

(Configuration-Navigation system-Touch panel)
The touch panel 20 receives various manual inputs from the user when pressed by the user's finger or the like. The touch panel 20 is formed to be transparent or translucent, and is provided on the front surface of the display 30 so as to overlap the display surface of the display 30. As the touch panel 20, for example, a publicly known touch panel provided with operation position detecting means by a resistance film method or a capacitance method can be used.

(Configuration-Navigation system-Display)
The display 30 is a display unit that displays an image guided by the navigation device 50. The specific configuration of the display 30 is arbitrary, and a flat panel display such as a known liquid crystal display or organic EL display can be used.

(Configuration-Navigation system-Speaker)
The speaker 40 is output means for outputting various sounds based on the control of the navigation device 50. The specific form of the sound output from the speaker 40 is arbitrary, and it is possible to output a synthesized sound generated as necessary or a sound recorded in advance.

(Configuration-Navigation system-Navigation device)
The navigation device 50 is a device that performs navigation such as travel route guidance of the host vehicle, and includes a control unit 51 and a data recording unit 52.

(Configuration-Navigation system-Navigation device-Control unit)
The control unit 51 is a control means for controlling the navigation device 50. Specifically, the CPU, various programs interpreted and executed on the CPU (basic control programs such as an OS, and specific functions activated on the OS) And an internal memory such as a RAM for storing the program and various data. In particular, the vehicle speed control program according to the present embodiment is installed in the navigation device 50 via an arbitrary recording medium or network, thereby substantially configuring each unit of the control unit 51.

  The control unit 51 includes a control target point determination unit 51a, a control start point specification unit 51b, a fixed point specification unit 51c, a passability determination unit 51d, a speed control unit 51e, and a notification control unit 51f in terms of functional concept. The control target point determination unit 51a becomes a target point for vehicle speed control based on the map information stored in the map information DB 52a described later and the current position of the vehicle acquired by the current position acquisition unit 10. A control target point for determining whether or not a control target point to be obtained exists in each of at least two or more branch roads among a plurality of branch roads branching from a branch point existing in front of the traveling direction of the vehicle traveling road It is a determination means. When the control target point determination unit 51a determines that the control target point exists in each of two or more branch roads, the control start point specifying unit 51b targets each of the control target points and controls the control target point The control start point specification that specifies the control start point when the vehicle is speed-controlled at the predetermined first reference acceleration / deceleration until the vehicle reaches the control target point so that the vehicle speed at the time of reaching the predetermined speed is reached. Means. The fixed point specifying unit 51c specifies a fixed point that is a point that exists in each of two or more branch roads and that can determine the current position of the vehicle after passing through the branch point. Means. The passability determination unit 51d is a control that exists in two or more branch paths based on the control start point specified by the control start point specifying unit 51b and the fixed point specified by the fixed point specifying unit 51c. It is a passability determination unit that determines whether there is a control target point in time even if the speed control is started after passing through the fixed point. The speed control unit 51e is a control target that is determined to be in time even if the speed control is started after passing through the fixed point by the passability determination unit 51d from among the control target points existing on two or more branch paths. Speed control means for controlling the speed of the vehicle before reaching the branch point, excluding the point. When the speed control unit 51e controls the speed of the vehicle at the second reference acceleration / deceleration, the notification control unit 51f may control the speed of the vehicle at an acceleration / deceleration greater than the first reference acceleration / deceleration. Is a notification control means for performing control for notifying the driver of the vehicle. Specific processing performed by these units will be described later.

(Configuration-Navigation system-Navigation device-Data recording unit)
The data recording unit 52 is a recording unit that records programs and various data necessary for the operation of the navigation device 50, and is configured using, for example, a hard disk (not shown) as an external recording device. However, any other recording medium including a magnetic recording medium such as a magnetic disk or an optical recording medium such as a DVD or a Blu-ray disk can be used instead of or together with the hard disk.

  The data recording unit 52 includes a map information database (hereinafter, the database is referred to as “DB”) 52a. The map information DB 52a is map information storage means for storing map information. “Map information” is information necessary for specifying various positions including an intersection and a temporary stop point. For example, intersection data (intersection coordinates, etc.), map display data for displaying a map on the display 30, and A branch angle between a plurality of branch paths branching from each branch point is included.

(Configuration-ECU)
The ECU 2 is an engine control unit that controls the engine of the host vehicle, and controls the speed of the host vehicle in cooperation with the navigation device 50 by controlling an engine ignition mechanism, a fuel supply mechanism, an intake / exhaust mechanism, and the like (not shown). To do. Since the ECU 2 can be configured in the same manner as in the prior art, a detailed description thereof will be omitted.

(Processing-Speed control processing)
Next, speed control processing executed by the speed control system configured as described above will be described. FIG. 2 is a flowchart of the speed control process. This speed control process is a process for controlling the speed of the vehicle. For example, the speed control process is automatically activated after the start of traveling of the host vehicle and is repeatedly executed at predetermined intervals. In the following description of each process, a process that does not specify the control subject is assumed to be executed by the control unit 51 of the navigation device 50, and a case where the information acquisition source or acquisition route is not specified is known timing and It is preliminarily stored in the data recording unit 52 of the navigation device 50 by a known method, or is input by the user or the like via the touch panel 20 of the navigation device 50. Step is abbreviated as “S”.

  First, the current position acquisition unit 10 acquires the coordinates of the current position of the host vehicle (SA1). Next, the control target point determination unit 51a acquires the coordinates of the control target point existing ahead in the traveling direction of the host vehicle (SA2). Specifically, based on the map information acquired from the map information DB 52a and the coordinates of the current position of the host vehicle acquired in SA1, the traveling road of the host vehicle is identified and set to the identified traveling road. The coordinates of the control target point that is the control target point and exists ahead of the traveling direction of the host vehicle are acquired from the map information. Here, the “control target point” is a point that can be a target point for speed control of the vehicle, and its determination method is arbitrary. For example, an entry point to a curve having a predetermined curvature or more, a lane junction point, etc. The entry point to. Or you may preset the information which shows whether each link etc. correspond to a control object point in the link data etc. which are contained in map information. Regarding the range of control target points acquired in this way, for example, all the control target points existing within a predetermined distance (for example, within 1 km) ahead of the traveling direction of the host vehicle with respect to the coordinates of the current position of the host vehicle. Get the coordinates.

  Then, the control target point determination unit 51a determines whether or not the coordinates of the control target point have been acquired in SA2 (SA3), and if not acquired (SA3, No), it is necessary to continue the speed control process. If there is no, the speed control process is terminated. On the other hand, when it is acquired (SA3, Yes), it is determined whether or not there are a plurality of coordinates of the control target point acquired at SA2 (SA4), and when it is not a plurality (when there is only one). (SA4, No), the coordinates of the acquired control target point are finally selected as the coordinates of the control target point that is the target of the actual speed control, and the speed control is performed by a known method (SA8). . This speed control is performed in cooperation between the navigation device 50 and the ECU 2 (the same applies to the speed control hereinafter).

  On the other hand, when there are a plurality (SA4, Yes), the coordinates of the plurality of control target points are at least 2 out of a plurality of branch roads that branch from a branch point existing ahead in the traveling direction on the traveling road of the host vehicle. It is determined whether or not the coordinates of the control target point exist in each of the two or more branch paths (SA5). Specifically, based on the map information acquired from the map information DB 52a, the coordinates of the branch point existing ahead in the traveling direction on the traveling road of the host vehicle are specified. Then, based on the coordinates of the specified branch point and the coordinates of the control target point acquired in SA2, whether or not the coordinates of the plurality of control target points exist in each of at least two or more branch paths. judge. FIG. 3 is an explanatory diagram illustrating the relationship between a branch point and a control target point. In FIG. 3, a branch point Ps exists in front of the current position of the host vehicle, and two branch roads W1 and W2 branch from the branch point Ps. P1 exists and the control target point P2 exists on the branch road W2. Therefore, in the case of FIG. 3, in SA5, it is determined that the coordinates of the plurality of control target points P1 and P2 exist in each of the two or more branch paths W1 and W2.

  In FIG. 2, when the coordinates of the control target point do not exist on each of the two or more branch roads (SA5, No), regardless of which of the two or more branch roads the host vehicle travels. From among the coordinates of the plurality of control target points, the coordinates of the control target point that is the target of the actual speed control are finally specified by a known method (SA7), and the coordinates of the specified control target point are used. Based on this, speed control is performed by a known method (SA8). As a method for specifying the coordinates of the control target point in SA7, for example, when the host vehicle is accelerated / decelerated at a predetermined first reference acceleration / deceleration so that the speed of the host vehicle becomes the target speed at a plurality of control target points. The coordinates of the control start point where control should be started for each control target point can be specified, respectively, and the coordinate of the control start point closest to the current position of the host vehicle can be specified as the coordinate of the control target point. The target speed, the first reference acceleration / deceleration, and the control start point will be described later.

  However, when the coordinates of the control target point exist on each of two or more branch roads (SA5, Yes), it is impossible to accurately predict which of the two or more branch roads the host vehicle will travel. From this, since it is not possible to immediately specify which of the coordinates of the control target point existing in each of the two or more branch paths should be subjected to the speed control, the control target point selection determination process is started (SA6). .

(Processing-Speed control processing-Control target point selection determination processing)
The control target point selection determination process will be described. FIG. 4 is a flowchart of control target point selection determination processing. In this processing, the control start point specifying unit 51b refers to the map information acquired from the map information DB 52a, and calculates the distance from the coordinates of the branch point to each of the coordinates of the plurality of control target points acquired in SA2 of FIG. Obtain (SB1).

  Moreover, the control start point specific | specification part 51b acquires the target speed at the time of making each control object point into the object of speed control (SB2). Here, the “target speed” is a speed that is a target of speed control, and is a speed that should be taken when the host vehicle passes through the control target point. The target speeds may be the same at a plurality of control target points, or may be different from each other. The method for determining the target speed is arbitrary. For example, when the control target point is an entry point to a curve, the target speed is determined based on the curvature or speed limit of the curve, or the control target point is a lane. If there is an entry point to the junction, it is determined based on the speed limit of the road that is the destination. Alternatively, a target speed when each link corresponds to a control target point may be set in advance in the link data included in the map information.

  Next, the control start point specifying unit 51b specifies the coordinates of the control start point corresponding to the coordinates of each control target point (SB3). Here, the “control start point” is a point at which speed control is started. Specifically, each control target is based on the target speed, the predetermined first reference acceleration / deceleration, and the predetermined first reference speed when each control target point acquired in SB2 is the target of speed control. Calculate the distance from each point to each control start point. Then, from the coordinates of the respective control target points acquired in SB1, the coordinates closer to the traveling direction by the calculated distance are specified as the coordinates of the control start point. Here, the “first reference acceleration / deceleration” is an upper limit value of the acceleration / deceleration for safely accelerating / decelerating without giving the driver unpleasant feeling, and is set to 0.1 G, for example. Further, the “first reference speed” is a speed that becomes a reference when starting speed control by the first reference acceleration / deceleration at the control start point, and a speed estimated as the speed of the host vehicle is set. The first reference speed can be determined by estimating the speed of the host vehicle by a known method. For example, the speed limit of the traveling road on which the host vehicle is currently traveling can be used.

  FIG. 5 shows the relationship between the speed and the distance related to speed control. In this graph, the horizontal axis indicates the distance from the current position of the host vehicle to each position related to speed control, and the vertical axis indicates the speed of the host vehicle. Here, as shown in FIG. 3, the two branch roads W1 and W2 branch from the branch point Ps, the control target point P1 exists in the branch path W1, and the branch road W2 has a control. The case where the target point P2 exists is shown. Moreover, the case where the target speed V1 of the control target point P1 is set to be different from the target speed V2 of the control target point P2 is shown.

  Here, the method for specifying the control start point S1 corresponding to the control target point P1 will be conceptually described. A curve indicating the first reference acceleration / deceleration G1 so as to pass through the control target point P1 (hereinafter, referred to as the first reference adjustment rate). A position where the speed represented by the first reference acceleration / deceleration curve matches the first reference speed Vs1 is specified as the control start point S1. Further, the method of specifying the control start point S2 corresponding to the control target point P2 will be conceptually described. A first reference acceleration / deceleration curve is drawn so as to pass through the control target point P2, and is expressed by the first reference acceleration / deceleration curve. The position at which the speed to be matched with the first reference speed Vs1 is specified as the control start point S2. Here, the first reference speed Vs1 at the control target point P1 and the first reference speed Vs1 at the control target point P2 are the same, but different reference speeds may be employed.

  Next, the fixed point specifying unit 51c specifies a fixed point that is a point that exists in each of two or more branch roads and that can determine the current position of the vehicle after passing through the branch point. Therefore, the fixed point specifying process is activated (SB4). That is, even when the host vehicle passes through a branch point and enters one of two or more branch roads, the vehicle enters based on the current position of the host vehicle acquired by the current position acquisition unit 10. It is difficult to determine the branch road after the own vehicle has traveled to some extent from the branch point. This is because the accuracy of the current position of the host vehicle acquired by the current position acquisition unit 10 is limited. Therefore, the coordinates of the fixed point that can determine the branch road that has entered are specified by the fixed point specifying process.

(Processing-Speed control processing-Control target point selection determination processing-Confirmed point identification processing)
FIG. 6 is an explanatory diagram for explaining the concept of specifying the coordinates of a fixed point. As shown in FIG. 6, when two branch roads W1 and W2 branch from the branch point Ps as in FIG. 3, the error Ci of the position of the host vehicle between the branch roads W1 and W2 is Ci = (2Li · sin θ) / 2 (hereinafter, expression 1). Here, θ is a branch angle at a branch point (link angle between links set in each branch path), and Li is a travel distance from the branch point Ps to the position Pi1 of the branch path W1 = from the branch point Ps. This is the travel distance to the position Pi2 of the branch road W2. The error Ci is considered as a route cost caused by selecting one of the branch roads W1 and W2, and the host vehicle travels from the branch point Ps to the positions Pi1 and Pi2 of the branch roads W1 and W2. A point where the accumulated value of the route cost Ci becomes a predetermined threshold Th is defined as a fixed point.

  FIG. 7 is a flowchart of the fixed point specifying process. Initially, the fixed point specific | specification part 51c acquires the map information containing the branch angle of a branch road from map information DB52a (SC1). The “branch angle” is not only a horizontal branch angle that is a branch angle when the branch path exists on the same horizontal plane, but also a vertical branch angle that is a branch angle when the heights of the branch paths differ from each other, A composite branch angle in which the horizontal branch angle and the vertical branch angle are combined is included.

  Next, the fixed point specifying unit 51c determines the distance to each position from the branch angle acquired at SC1 and the coordinates of the branch point acquired at SB1 in FIG. 4 to the coordinates of each control target point. Based on the above, the route cost is calculated by the above-described formula 1 (SC2). For example, as shown in FIG. 6, in the case where a fixed point is specified for two branch roads W1 and W2, positions Pi1 and Pi2 of the same distance Li in the branch roads W1 and W2 are set from the branch point Ps. A straight line connecting the positions Pi1 and Pi2 is drawn. Then, the route cost Ci is calculated by the above equation 1 for the triangle formed by the straight line and the branch paths W1 and W2. Such calculation is repeated in the same manner while changing the positions Pi1 and Pi2 from the coordinates of the branch point Ps to the coordinates of each control target point.

  Then, the fixed point specifying unit 51c specifies the coordinates of the fixed point based on the route cost calculated in SC2 and the predetermined threshold (SC3). For example, the route costs Ci of the positions Pi1 and Pi2 calculated in SC2 are integrated until the positions Pi1 and Pi2 approach the coordinates of each control target point from the coordinates of the branch point Ps until the predetermined threshold Th is reached. Then, the positions Pi1 and Pi2 that have reached the predetermined threshold Th are specified as the coordinates of the fixed point. This completes the fixed point specifying process.

  Thereafter, the process returns to the control target point selection determination process of FIG. 4, and the control start point specifying unit 51b does not meet the control target point unless the speed control is started before the host vehicle passes the fixed point. It is determined whether or not a point exists (SB5). This determination can be made based on the relative positional relationship between the coordinates of the control start point specified in SB3 and the coordinates of the fixed point specified in SC3 in FIG. For example, in the case of the example in FIG. 5, since the control start point S1 is on the front side in the traveling direction with respect to the confirmed point PD, the own vehicle passes through the confirmed point PD when the own vehicle reaches the control start point S1. It will be understood that it will not be in time unless the speed control for the control target point P1 is started. On the other hand, since the control start point S2 is behind the confirmed point PD in the traveling direction, the control is performed when the own vehicle reaches the control start point S2 (after the own vehicle passes the confirmed point PD). It can be seen that even if the speed control for the target point P2 is started, it is still in time. Hereinafter, if necessary, a control target point that is in time even if speed control is started after the host vehicle has passed the fixed point is referred to as a “controllable point after passing”, and the speed control is performed after the host vehicle passes the fixed point. A control target point that is not in time because it has started is referred to as a “pre-pass control required point”.

  In FIG. 4, when there is no pre-pass control required point (that is, when there is only a post-pass controllable point) (SB5, No), the host vehicle actually travels after the host vehicle passes the fixed point. And the coordinates of the control target point that is the target of the actual speed control are finally specified by a known method from among the coordinates of the control target point existing on the specified branch path (SB7). ). This specification can be performed, for example, in the same manner as SA7 in FIG. Then, the control target point selection determination process is terminated and the process returns to the speed control process of FIG. 2, and the speed control is performed on the coordinates of the finally selected control target point by a known method (SA8).

  On the other hand, in FIG. 4, when there is a pre-pass control point (ie, when there is only a pre-pass control point, or when both a pre-pass control point and a post-control possible point exist) (SB5 , Yes), since the control target point to be actually targeted may differ depending on which of the branch road the host vehicle travels, the speed control process for each control region is started (SB6).

(Processing-Speed control process-Control target point selection determination process-Control area-specific speed control process)
The speed control process for each control area will be described. FIG. 8 is a flowchart of the speed control process for each control area. As a premise for performing this process, a second reference acceleration / deceleration G2 and control areas A to C are set. The “second reference acceleration / deceleration” is a value set as an acceleration / deceleration greater than the first reference acceleration / deceleration. For example, 0.15G is set. As shown in FIG. 5, the control area A is an area surrounded by a first reference acceleration / deceleration curve that passes through the horizontal axis, the vertical axis, and the control target point P1 closest to the host vehicle. When the traveling state of the own vehicle (the intersection of the position and speed of the own vehicle; the same applies hereinafter) is within this control area A, the first reference adjustment is performed regardless of whether or not the own vehicle has passed the fixed point. By performing acceleration / deceleration by acceleration / deceleration not exceeding the speed G1, the speed of the host vehicle at the control target point P1 can be set to the target speed V1. The control region B is a first reference acceleration / deceleration curve, a curve indicating the second reference acceleration / deceleration G2 drawn so as to pass through the control target point P1 closest to the host vehicle (hereinafter referred to as a second reference acceleration / deceleration curve), And an area surrounded by a fixed point. When the traveling state of the host vehicle is in the control region B, the first reference acceleration / deceleration G1 is larger than the first reference acceleration / deceleration G2 but does not exceed the second reference acceleration / deceleration G2 even after the host vehicle passes through the fixed point. By performing acceleration / deceleration by acceleration / deceleration, the speed of the host vehicle at the control target point P1 can be set to the target speed V1. The control region C is a region surrounded by the horizontal axis, the second reference acceleration / deceleration curve, the first reference acceleration / deceleration curve drawn so as to pass through the second closest control target point P2 from the host vehicle, and the fixed point. is there. When the traveling state of the host vehicle is in the control region C, acceleration / deceleration is performed by acceleration / deceleration that does not exceed the first reference acceleration / deceleration G1 even after the host vehicle passes through the fixed point. The speed of the host vehicle at the control target point P2 can be set to the target speed V2.

  Under such a premise, as shown in FIG. 8, the control start point specifying unit 51b specifies the second reference speed (SD1). The “second reference speed” is a speed that becomes a reference when starting speed control by the second reference acceleration / deceleration at the control start point. The method of specifying the second reference speed will be conceptually described. As shown in FIG. 5, a second reference acceleration / deceleration curve is drawn so as to pass through the control target point P1, and the second reference acceleration / deceleration curve and the fixed point are drawn. A speed corresponding to the intersection with the second reference speed Vs2 is specified.

  Next, the speed control unit 51e monitors whether or not the driver's accelerator is turned off by the driver (SD2). When the accelerator is turned off (SD2, Yes), based on the current running state of the host vehicle (the position and speed of the host vehicle) at the time when the accelerator is turned off, It is determined which of the control areas A to C the running state is in, and control according to the specified control areas A to C is performed (SD3).

  That is, when the accelerator is turned off, when the current position of the host vehicle is a position before the determined point and the traveling state of the host vehicle is in the control region A, the speed control unit 51e The coordinates of the control target point whose start point is closest to the current position of the host vehicle (the coordinate of the control target point at which the acceleration / deceleration required to make the speed of the host vehicle at the control target point the first reference speed) is the largest. Finally, it is selected as the coordinates of the control target point that is the target of the actual speed control. In the example of FIG. 5, the coordinates of the control target point P1 are finally selected. Then, the speed control process for each control region is finished and the control target point selection determination process is finished. In the speed control process of FIG. 2, the speed control unit 51e performs speed control by a known method (SA8). . In this case, the speed control unit 51e performs speed control at an acceleration / deceleration equal to or lower than the first reference acceleration / deceleration.

  On the other hand, in SD3, when the traveling state of the host vehicle at the time when the accelerator is turned off is in the control region B, the coordinates of the control target point P1 that is closest to the host vehicle are set as the target of the actual speed control. Finally, it is selected as the coordinates of the point, and the speed control process for each control region is completed and the control target point selection determination process is finished. In the speed control process of FIG. (SA8). In this case, the speed control unit 51e needs to perform speed control at an acceleration / deceleration greater than the first reference acceleration / deceleration and less than or equal to the second reference acceleration / deceleration. When speed control is performed at an acceleration / deceleration greater than the first reference acceleration / deceleration in this way, the notification control unit 51f can control the vehicle speed at an acceleration / deceleration greater than the first reference acceleration / deceleration for the driver. Control for notifying the driver of the vehicle that there is a possibility. Although the specific content of this control is arbitrary, for example, text data such as “I greatly accelerate / decelerate” is displayed on the display 30, or a voice message such as “I greatly accelerate / decelerate” is output from the speaker 40. To do.

  Alternatively, in SD3, when the traveling state of the host vehicle at the time when the accelerator is turned off is in the control region C, the coordinates of the control target point P2 that is second closest to the host vehicle are the targets of the actual speed control. The speed control unit 51e is finally selected as the coordinates of the control target point, ends the speed control process for each control region and ends the control target point selection determination process. In the speed control process of FIG. Is carried out by a known method (SA8). In this case, the speed control unit 51e performs the speed control at an acceleration / deceleration equal to or lower than the first reference acceleration / deceleration. This completes the speed control process.

(effect)
As described above, according to the present embodiment, speed control is performed after passing through the fixed point among the control target points existing in two or more branch paths based on the control start point and the fixed point. It is determined whether there is a control target point that is in time even if it starts, and excludes the control target point that is determined to be in time even if it starts after passing through the fixed point from the control target point Since the speed of the vehicle is controlled before reaching the branch point, a candidate for a control target point is set for each of a plurality of branch paths that branch from the branch point, and the vehicle Even when it is impossible to predict whether the vehicle will travel, it is possible to accurately control the speed of the vehicle.

  Further, since the fixed point is specified based on the branch angle of the branch road included in the map information, the fixed point can be accurately specified by considering the difference in the branch angle of the branch road.

[Modifications to Embodiment]
While the embodiments of the present invention have been described above, the specific configuration and means of the present invention may be arbitrarily modified and improved within the scope of the technical idea of each invention described in the claims. Can do. Hereinafter, such a modification will be described.

(About problems to be solved and effects of the invention)
First, the problems to be solved by the invention and the effects of the invention are not limited to the above contents, and may vary depending on the implementation environment and details of the configuration of the invention. May be solved, or only some of the effects described above may be achieved. For example, even if the vehicle speed control cannot be performed completely accurately, the speed control accuracy can be improved slightly compared to the conventional case, or the speed control accuracy comparable to the conventional case can be improved. If it can be achieved by a technique different from the above, the problem of the present invention has been solved.

(About distribution and integration)
Further, each of the electrical components described above is functionally conceptual and does not necessarily need to be physically configured as illustrated. In other words, the specific form of distribution / integration of each part is not limited to the one shown in the figure, and all or a part thereof may be functionally or physically distributed / integrated in arbitrary units according to various loads and usage conditions. Can be configured. For example, the components of the vehicle speed control system may be distributed and connected to each other via a network.

1 Navigation system 2 ECU
DESCRIPTION OF SYMBOLS 10 Current position acquisition part 20 Touch panel 30 Display 40 Speaker 50 Navigation apparatus 51 Control part 51a Control target point determination part 51b Control start point specification part 51c Confirmation point specification part 51d Passability determination part 51e Speed control part 51f Information control part 52 Data recording Department 52a Map information DB

Claims (4)

Map information storage means for storing map information;
Current position acquisition means for acquiring the current position of the vehicle;
Based on the map information stored in the map information storage unit and the current position of the vehicle acquired by the current position acquisition unit, a control target point that can be a target point for speed control of the vehicle is Control target point determination means for determining whether or not each of at least two or more branch roads among a plurality of branch roads branching from a branch point existing ahead in the traveling direction of the vehicle traveling road;
When it is determined by the control target point determination means that the control target point is present in each of the two or more branch paths, the control target point is set as the target, and when the control target point reaches the control target point Control start point specifying means for specifying a control start point when the vehicle is speed-controlled at a predetermined first reference acceleration / deceleration until the vehicle reaches the control target point so that the vehicle speed becomes a predetermined speed;
A fixed point specifying means for specifying a fixed point that is a point that exists in each of the two or more branch roads and that can determine the current position of the vehicle after passing through the branch point;
Based on the control start point specified by the control start point specifying unit and the fixed point specified by the fixed point specifying unit, among the control target points existing in the two or more branch paths A passage permission determination means for determining whether or not there is a control target point in time even if the speed control is started after passing through the fixed point;
From among the control target points existing on the two or more branch paths, exclude the control target points that are determined to be in time even if the speed control is started after passing through the fixed point by the passage permission determination means. Speed control means for controlling the speed of the vehicle before reaching the branch point;
A vehicle speed control system comprising: The map information storage means stores the map information including a branch angle of the branch road,
The fixed point specifying unit specifies the fixed point based on a branch angle of the branch path included in the map information stored in the map information storage unit;
The vehicle speed control system according to claim 1. A map information storage step for storing the map information in the map information storage means;
A current position acquisition step for acquiring the current position of the vehicle;
Based on the map information stored in the map information storage step and the current position of the vehicle acquired in the current position acquisition step, a control target point that can be a target point for speed control of the vehicle, A control target point determination step for determining whether or not each of at least two or more branch roads among a plurality of branch roads branching from a branch point existing forward in the traveling direction of the vehicle traveling road;
When it is determined by the control target point determination step that the control target point exists in each of the two or more branch paths, the control target point for each of the control target points and the time when the control target point is reached A control start point specifying step for specifying a control start point when the vehicle is speed-controlled at a predetermined first reference acceleration / deceleration until the vehicle reaches the control target point so that the vehicle speed becomes a predetermined speed;
A fixed point specifying step for specifying a fixed point that is a point that exists in each of the two or more branch roads and that allows the current position of the vehicle to be determined after passing through the branch point;
Based on the control start point specified in the control start point specifying step and the fixed point specified in the fixed point specifying step, among the control target points existing in the two or more branch paths, A passability determination step for determining whether or not there is a control target point in time even if speed control is started after passing through the fixed point; and
From among the control target points existing on the two or more branch roads, exclude the control target points that are determined to be in time even if the speed control is started after passing through the fixed point in the passability determination step. A speed control step for controlling the speed of the vehicle before reaching the branch point;
A vehicle speed control method.   A vehicle speed control program for causing a computer to execute the method according to claim 3.

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