JP2017004267A - Vehicle speed control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a vehicle speed control technique that enables a vehicle speed to be smoothly adjusted even when a speed limit changes.SOLUTION: In a vehicle speed control device 102, a first speed limit detecting unit detects a first speed limit of a first road X on which a subject vehicle 100 travels. A second speed limit detecting unit detects a second speed limit of a second road Y which connects to the first road X in a travelling direction of the subject vehicle 100. A limit setting unit sets a limit value for a travel speed of the subject vehicle 100, based on the first speed limit. A limit controlling unit executes a predetermined processing for limiting a vehicle speed when the travel speed of the subject vehicle 100 reaches the limit value. The limit setting unit changes setting of the limit value to a higher value at a spot Q closer than a connection spot P of the first road X and the second road Y when the second speed limit is larger than the first speed limit.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a technique for controlling the vehicle speed, and more particularly to a technique for controlling the vehicle speed in accordance with a speed limit on a road.

  In recent years, automobiles are equipped with a large number of information collection devices (hereinafter referred to as “sensor units”) such as sensors and cameras to enhance information collection capabilities. Along with this, a large number of processors such as an ECU (Electronic Control Unit) for managing the sensor unit are also mounted on the vehicle.

  Enhancing information collection capabilities will advance driving support technology. One of them is a vehicle speed control device that limits the vehicle speed in order to realize safe driving. The vehicle speed control device sets a “limit value” as a guideline for the maximum speed. Then, when the vehicle speed approaches the limit value or exceeds the limit value, a process of urging the driver to decelerate or automatically decelerating the vehicle (hereinafter referred to as “vehicle speed limit process”) is executed.

  In Patent Literature 1, a road speed limit (legal speed) is recognized by capturing an image of a road sign or road surface sign of a road on which the host vehicle is traveling. The recognized speed limit becomes the limit value.

JP 2005-128790 A

  The present inventor plans not only the speed limit (hereinafter referred to as “first speed limit”) of the road on which the vehicle travels (hereinafter referred to as “first speed limit”) but also a travel schedule ahead of the first road. The necessity of detection was also recognized for the speed limit (hereinafter referred to as “second speed limit”) of the road (hereinafter referred to as “second road”). For example, in order to smoothly merge from a low-speed first road to a high-speed second road, it is necessary to allow acceleration immediately before the merge. For this purpose, it may be necessary to recognize in advance that there is a second high-speed road ahead of the first road and adjust the limit value.

  The present invention has been made in view of such circumstances, and a main object thereof is to realize a vehicle speed control technique that enables smooth vehicle speed adjustment in a situation where the speed limit of a road changes.

A vehicle speed control device according to an aspect of the present invention is connected to a first speed limit detection unit that detects a first speed limit of a first road on which the host vehicle travels, and the first road in the traveling direction of the host vehicle. A second speed limit detecting unit for detecting a second speed limit of the second road; a limit setting unit for setting a limit value for the travel speed of the host vehicle based on the first speed limit; A limit control unit that executes a predetermined vehicle speed limit process when the speed reaches a limit value.
When the second speed limit is greater than the first speed limit, the limit setting unit changes the setting of the limit value to a higher value at a point before the connection point between the first road and the second road. .

  This vehicle speed control device sets a limit value that regulates the traveling speed. The limit value is set based on the speed limit of the road. When shifting from a low-speed road to a high-speed road, the vehicle speed can be adjusted smoothly by increasing the limit value before reaching the connection point of the two roads.

  According to the present invention, it is possible to perform vehicle speed limitation that facilitates smooth vehicle speed adjustment even when the speed limit changes.

It is a 1st schematic diagram for demonstrating the road condition where a 2nd speed limit is larger than a 1st speed limit. It is a 2nd schematic diagram for demonstrating the road condition where a 2nd speed limit is larger than a 1st speed limit. It is a schematic diagram for demonstrating the road condition where a 2nd speed limit is smaller than a 1st speed limit. It is a functional block diagram of a vehicle speed control device. It is a 1st flowchart which shows the process of the setting of a control value, and a vehicle speed restriction | limiting determination. It is a 2nd flowchart which shows the process of the setting of a control value, and a vehicle speed restriction | limiting determination.

  First, with reference to FIGS. 1 to 3, the road situation in which the speed limit changes and the concept of vehicle speed control at that time will be described.

FIG. 1 is a first schematic diagram for explaining a road situation in which the second speed limit is larger than the first speed limit.
FIG. 1 shows a situation in which a host vehicle 100 traveling on a road X (first road) enters a road Y (second road) having a larger speed limit. The first speed limit on the first road X is RX, and the second speed limit on the second road Y at the junction is RY. RY> RX.

  When the host vehicle 100 travels on the road X, a vehicle speed control device 102 (described in detail later) mounted on the host vehicle 100 acquires the first speed limit RX of the first road X that is traveling, and the first speed limit RX Based on the above, the limit value rx1 is set. The first speed limit RX may be acquired from a road sign or road surface sign, or may be acquired from road information of a navigation system. It is sufficient if RX ≧ rx1. Here, it is assumed that RX> rx1. In the present embodiment, when the vehicle speed S of the host vehicle 100 traveling on the first road X becomes equal to or greater than the limit value rx1, the vehicle speed control device 102 executes a predetermined vehicle speed limit process. Specifically, the driver is instructed to decelerate. When the vehicle speed S greatly exceeds the limit value rx1, or when the driver does not perform the deceleration operation for a certain period of time despite the deceleration instruction, the vehicle may be automatically decelerated.

  When the host vehicle 100 travels on the road Y, the vehicle speed control device 102 acquires the second speed limit RY and sets the limit value ry1 based on the second speed limit RY. The second speed limit RY may be acquired from a road sign or road marking, or may be acquired from road information of a navigation system. It is sufficient if RY ≧ ry1.

  When the host vehicle 100 on the first road X approaches the connection point P (a road junction), acceleration is necessary to smoothly join the vehicle train on the second road Y. However, if the limit value rx1 set on the first road X is too low compared to the second speed limit RY, acceleration may be excessively restricted. Therefore, in the present embodiment, the buffer zone X3 is set before reaching the merge point P, and when the host vehicle 100 enters the buffer zone X3, the limit value rx1 is set to a larger rx2 (> rx1). Control so that smooth acceleration is not hindered.

  When the host vehicle 100 is in the unrecognized region X1 far from the connection point P on the first road X, the vehicle speed control device 102 does not acquire the second speed limit RY on the second road Y. When the host vehicle 100 is in the recognition area X2 closer to the connection point P than the unrecognized area X1, not only the first speed limit RX but also the second speed limit RY is acquired. At this time, the vehicle speed control device 102 sets a buffer zone X3 close to the connection point P. The start point Q of the buffer zone X3 is set to a point that is a predetermined length before the junction point P. The start point Q may be set closer to the front as the speed difference between the first speed limit RX and the second speed limit RY is larger.

  When the host vehicle 100 actually enters the buffer zone X3, the limit value is changed from rx1 to a larger rx2. When the own vehicle 100 enters the second road Y beyond the connection point P, the limit value is changed from rx2 to ry1. rx2 = ry1 may be sufficient.

  Note that the boundary between the unrecognized region X1 and the recognized region X2 is arbitrary. When the second speed limit RY of the second road Y can be acquired from the navigation system, it may be fixedly set such as a point 500 meters from the connection point P. When the second speed limit RY is acquired from the road sign of the second road Y by the camera, the recognition area X2 may be started from a point where image recognition of the second speed limit RY of the second road Y is successful. .

FIG. 2 is a second schematic diagram for explaining a road situation in which the second speed limit is larger than the first speed limit.
FIG. 2 shows a situation where the host vehicle 100 traveling on the first road X having a narrow road width enters the second road Y having a wider road width. The relationship between the first speed limit RX of the first road X and the RY of the second speed limit of the second road Y that is the merging destination is RY> RX.

  Also in this case, the host vehicle 100 sets the limit value rx1 based on the first limit speed RX in the unrecognized region X1. When the host vehicle 100 enters the recognition area X2, the second speed limit RY is acquired and the buffer zone X3 is set. When the host vehicle 100 enters the buffer zone X3, the limit value is changed to rx2 larger than rx1.

FIG. 3 is a schematic diagram for explaining a road situation in which the second speed limit is smaller than the first speed limit.
FIG. 2 shows a situation where the host vehicle 100 traveling on the first road X having a large road width enters the second road Y having a narrower road width. The relationship between the first speed limit RX on the first road X and the second speed limit RY on the second road Y is RY <RX.

  As shown in FIG. 3, when the speed limit decreases after passing through the connection point P, the buffer zone X3 is not set before the connection point P. This is because if the vehicle decelerates too early, it may cause an interruption of another vehicle. Therefore, the point where the limit value is lowered is set after the connection point P.

FIG. 4 is a functional block diagram of the vehicle speed control device 102.
Each component of the vehicle speed control device 102 is centered on an arbitrary computer CPU, memory, a program that realizes the components shown in the figure loaded in the memory, a storage unit such as a hard disk for storing the program, and a network connection interface. It is realized by any combination of hardware and software. It will be understood by those skilled in the art that there are various modifications to the implementation method and apparatus. Each figure described below shows functional unit blocks, not hardware unit configurations.

  The vehicle speed limiting function of the vehicle speed control device 102 becomes effective when the main switch 120 is turned on. The vehicle speed control device 102 includes a speed limit detecting unit 110, a limit setting unit 116, and a limit control unit 118. The speed limit detector 110 detects the speed limit from road signs, road markings, navigation information, and the like. The imaging device 104 captures road signs and road markings and transfers the image information to the speed limit detection unit 110. The speed limit detection unit 110 detects the speed limit of the road from this image information and road information sent from the navigation device 106. Speed limit detection unit 110 includes a first speed limit detection unit 112 and a second speed limit detection unit 114. The first speed limit detector 112 detects the first speed limit RX of the first road X, and the second speed limit detector 114 detects the second speed limit RY of the second road Y.

  The limit setting unit 116 sets a limit value based on the speed limit. The limit setting unit 116 also sets the buffer zone X3. When the vehicle speed (traveling speed) obtained from the speedometer 108 is equal to or higher than the limit value, the limit control unit 118 executes a vehicle speed limit process.

  The changeover switch 124 switches the limit setting unit 116 to either the automatic setting mode or the manual setting mode. In the automatic setting mode, the limit setting unit 116 automatically sets a limit value based on the speed limit. In the manual setting mode, the driver sets a limit value with the selection switch 126. The current vehicle speed can be set as a limit value as it is.

  The restriction setting unit 116 recognizes the connection point P from the navigation information or the like, and sets the start point Q of the buffer zone X3 at a point before the connection point P by a predetermined length. As a modification, the restriction setting unit 116 may set the start point Q of the buffer zone X3 with reference to the instruction information from the direction indicator 122. In this case, the restriction setting unit 116 may determine that the driver is in front of the merge point P when operating the direction indicator 122. A point where the direction indicator 122 is operated or a point after a predetermined time after the operation may be set as the start value point Q.

  The start point Q of the buffer zone X3 may be set before the connection point P or the branch point. A point indicating the start or end of the road sign or a point in front of it may be set as the start point Q.

  The speed limit detection unit 110 may estimate the second speed limit RY based on the speed difference between the vehicle speed of the other vehicle traveling on the second road Y and the vehicle speed of the host vehicle 100. For example, when the vehicle speed of the host vehicle 100 on the first road X is 60 km / h and the speed of another vehicle running on the second road Y is 100 km / h, the difference between the first speed limit RX on the first road X and the speed 40 A value obtained by adding kilometers may be estimated as the second speed limit RY of the second road Y.

FIGS. 5 and 6 are flowcharts showing the process of setting the control value and determining the vehicle speed limit.
The processes shown in FIGS. 5 and 6 are repeatedly executed after the engine is started. In the present embodiment, the processes of S10 to S28 are periodically and continuously executed. In this flowchart, the limit value rx2 for the buffer zone X3 and the limit value ry1 for the second road RY are assumed to be the same.

  First, the first speed limit detection unit 112 acquires the first speed limit RX of the first road X on which the host vehicle 100 is traveling (S10). Next, the second speed limit detecting unit 114 acquires the second speed limit RY of the second road Y connected to the first road X in the traveling direction of the host vehicle 100 (S12).

  When the buffer zone X3 is set and the host vehicle 100 is inside the buffer zone X3 (Y in S14), the limit setting unit 116 sets a limit value ry based on the second speed limit RY (S16). Whether or not the host vehicle 100 is in the buffer zone X3 may be determined by a known position detection technique such as GPS (Global Posisioning System) information. When the host vehicle 100 has not reached the buffer zone X3 or when the buffer zone X3 is not set (N in S14), the limit setting unit 116 determines whether the relationship of RY> RX is satisfied (S18). When RY> RX (Y in S18), that is, when in the recognition area X2 shown in FIGS. 1 and 2, the restriction setting unit 116 sets the start point Q of the buffer zone X3. On the other hand, when RY ≦ RX or when the second speed limit RY cannot be detected (N in S18), the buffer zone X3 is not set. The limit setting unit 116 sets a limit value rx1 based on the first limit speed RX (S22).

Turning to FIG.
The restriction control unit 118 detects the vehicle speed S of the host vehicle 100 (S24). When the vehicle speed S is equal to or greater than the limit value (Y in S26), the limit control unit 118 executes a vehicle speed limit process (S28). When vehicle speed S <limit value (N in S26), S28 is skipped.

The vehicle speed control device 102 has been described above based on the embodiment.
In the present embodiment, when the host vehicle 100 enters the second high-speed road Y from the low-speed first road X, a buffer zone X3 for allowing acceleration is set before the connection point P. The limit value rx1 based on the first speed limit RX is set before entering the buffer zone X3, but when entering the buffer zone X3, the limit value rx1 is changed to a larger rx2 to prevent acceleration at the time of merging. The vehicle speed limiting process can be executed so as not to

  The present invention has been described based on the embodiments. The embodiments are exemplifications, and it will be understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are within the scope of the present invention. .

  DESCRIPTION OF SYMBOLS 100 Own vehicle, 102 Vehicle speed control apparatus, 104 Imaging apparatus, 106 Navigation apparatus, 110 Speed limit detection part, 112 1st speed limit detection part, 114 2nd speed limit detection part, 116 Limit setting part, 118 Limit control part, X3 Buffer zone.

Claims (1)

A first speed limit detecting unit for detecting a first speed limit of the first road on which the host vehicle travels;
A second speed limit detecting unit for detecting a second speed limit of a second road connected to the first road in the traveling direction of the host vehicle;
A limit setting unit for setting a limit value for the traveling speed of the host vehicle based on the first speed limit;
A limit control unit that executes a predetermined vehicle speed limiting process when the traveling speed of the host vehicle reaches the limit value,
When the second speed limit is greater than the first speed limit, the limit setting unit increases the limit value at a point before the connection point between the first road and the second road. A vehicle speed control device characterized in that the setting is changed to a high value.

Images