JP2008146169A - Cruise control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cruise control system which, when a plurality of vehicles are driven in a line, can increase the safety of the whole line of vehicles. <P>SOLUTION: The ECU 10 of a vehicle cruise control device 1 creates cruise plans for vehicles that form a line, starting with the vehicles surrounded on the front and rear by at least either the vehicles that form the line or vehicles that do not form a line. After cruise plans are created preferentially for vehicles likely to collide with vehicles in front and behind that are close to the center G of gravity of the line of vehicles, cruise plans for relatively safe vehicles not surrounded by other vehicles on the front and rear and located away from the center G of gravity of the line of vehicles are set, whereby the safety of the whole line of vehicles can be increased. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a traveling control system, and more particularly, to a traveling control system that forms a platoon with a plurality of vehicles and travels the vehicles.

2. Description of the Related Art Conventionally, there is one that performs vehicle running control by running a vehicle by forming a formation by a plurality of vehicles. For example, Patent Document 1 discloses a technique for controlling a probe car as a leading vehicle group or a whole traffic flow including a vehicle group in consideration of efficiency, safety, and the environment by appropriately controlling the probe car. It is disclosed. The technology of this Patent Document 1 inputs at least one of a probe car control strategy or a vehicle group strategy based on a road map database or traffic data, evaluates the validity of this strategy, determines an appropriate strategy, The determined strategy is transmitted to the probe car.
JP 2002-123894 A

  However, in the above technology, since the travel plan is determined from the probe car at the front of the platoon, the degree of freedom in the travel plan for the vehicles behind the platoon is reduced, and there is no room for control to prevent rear-end collisions. There is a drawback. For example, when the vehicle is decelerated in order from the first vehicle in the platoon, there is a possibility that the vehicle behind the platoon may be forced to decelerate suddenly in order to keep the distance between the vehicles, which may impair the safety of the vehicles in the entire platoon.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a travel control capable of further enhancing the safety of the vehicle of the entire platoon when the platoon is formed by a plurality of vehicles and the vehicle is traveled. To provide a system.

  The present invention is a travel control system for traveling a vehicle by forming a platoon with a plurality of vehicles, comprising travel plan generation means for generating a travel plan for each of the vehicles forming the platoon, It is characterized in that a travel plan is generated in order from a vehicle surrounded front and rear by at least one of a vehicle forming a convoy and a vehicle not forming a convoy.

  According to this configuration, the travel plan generation unit sequentially creates a travel plan from a vehicle that is enclosed in front and rear by at least one of a vehicle that forms a convoy and a vehicle that does not form a convoy. In order to generate a relatively safe vehicle travel plan in which the front and rear vehicles are not surrounded by other vehicles after the travel plan is preferentially created from the vehicles that may collide with the front and rear vehicles. As a result, the safety of vehicles in the entire platoon can be further increased.

  In this case, it is preferable that the travel plan generation unit generates the travel plan in order from the vehicle having the smallest sum of the inter-vehicle distance with the front vehicle and the inter-vehicle distance with the rear vehicle.

  According to this configuration, the travel plan generation means generates the travel plan in order from the vehicle having the smallest sum of the inter-vehicle distance with the front vehicle and the inter-vehicle distance with the rear vehicle, so the inter-vehicle distance and the rear with the front vehicle. Therefore, a travel plan is preferentially set from a vehicle having a small sum of the distances between the two vehicles and the possibility of a rear-end collision, and a travel plan suitable for the situation of each vehicle can be generated.

  Alternatively, in this case, it is preferable that the travel plan generation unit generates the travel plan in order from the vehicle closest to the center position in the platoon.

  According to this configuration, the travel plan generation means generates a travel plan in order from the vehicle closest to the center position in the platoon, so that the travel plan is preferentially set from the vehicle located in the densest part in the platoon, Furthermore, it is possible to generate a travel plan adapted to the situation of each vehicle.

  Particularly in this case, the center position in the platoon is preferably the center of gravity of the platoon calculated from the weight of each vehicle forming the platoon and the inter-vehicle distance between the vehicles.

  According to this configuration, the center position in the platoon is the center of gravity of the platoon calculated from the weight of each vehicle forming the platoon and the inter-vehicle distance between the respective vehicles. A travel plan is preferentially made from a vehicle with a high risk of rear-end collision or the like, and a travel plan adapted to the situation of each vehicle can be generated.

  Alternatively, the center position in the platoon is preferably the midpoint of a straight line connecting the front end of the first vehicle in the platoon and the rear end of the last vehicle.

  According to this configuration, the center position in the platoon is the midpoint of the straight line connecting the front end of the first vehicle in the platoon and the rear end of the rearmost vehicle, and based on only the positional relationship of the vehicles in the platoon, Since the center position is determined, there is an advantage that the calculation becomes easy.

  On the other hand, the travel plan generation means calculates safety indicators from the inter-vehicle distance and relative speed of each vehicle that forms the platoon with either the front or rear vehicle, and the travel plans from the vehicles with the lowest safety according to the indicators. Is preferably generated.

  According to this configuration, the travel plan generation means calculates the safety-related index from the inter-vehicle distance and the relative speed with respect to either the front or rear vehicle of each vehicle forming the platoon, and the vehicle with low safety based on the index For example, even if the vehicle is the first vehicle or the last vehicle in the platoon, if the vehicle is approaching a vehicle outside the platoon, the vehicle Therefore, it is possible to generate a travel plan suitable for the situation of each vehicle.

  According to the traveling control system of the present invention, when a vehicle is driven by forming a platoon with a plurality of vehicles, the safety of the vehicles in the entire platoon can be further enhanced.

  Hereinafter, a travel control system according to an embodiment of the present invention will be described with reference to the accompanying drawings.

  Hereinafter, the case where the traveling control system according to the present invention is applied to an in-vehicle vehicle traveling control apparatus will be described as an example. FIG. 1 is a schematic configuration diagram of a vehicle travel control apparatus according to the first embodiment. As shown in FIG. 1, the vehicle travel control apparatus according to the present embodiment is mounted on a vehicle and performs travel control of the vehicle. The vehicle travel control device 1 includes an ECU 10. The ECU 10 is an electronic control unit that performs overall control of the vehicle travel control device 1 and is configured mainly by a computer including a CPU, a ROM, and a RAM, for example. The ECU 10 functions as a travel plan generation unit that generates a travel plan for each vehicle forming the platoon.

  A vehicle equipped with the vehicle travel control device 1 includes an engine (internal combustion engine) 30 that is a main drive source and a brake device 34 that applies a braking force to each wheel. The vehicle is provided with a throttle actuator 32 for adjusting the opening of the throttle valve as means for adjusting the driving force of the engine 30. Further, the vehicle is provided with a brake actuator 36 for adjusting the hydraulic pressure supplied to the brake device 34 as means for adjusting the braking force of the brake device 34.

  In addition, it may replace with the engine 30 which is a drive source, a motor may be used, and the engine 30 and a motor may be used together.

  A vehicle equipped with the vehicle travel control device 1 is provided with a steering motor 44. The steering motor 44 applies a steering force to the steering force transmission mechanism of the vehicle to perform automatic steering. The steering motor 44 is attached to a steering force transmission mechanism such as a steering shaft, for example, and applies a steering force through a gear mechanism or the like. The steering motor 44 operates in accordance with a control signal output from the ECU 10. As the steering motor 44, it is preferable to use an assist motor used in an electric power steering steering system.

  The vehicle is also provided with a wheel speed sensor 41 for detecting the rotation of the wheel, a GPS (Global Positioning System) device 40, a radar sensor 45, and an image sensor 46. The ECU 10 takes in the detection outputs of these sensors, gives operation commands corresponding to the detection values of the sensors to the throttle actuator 32 and the brake actuator 36, respectively, and gives a desired braking / driving force to the engine 30 and the brake device 34. generate.

  The wheel speed sensor 41 functions as a means for detecting the vehicle speed, and for example, an electromagnetic pickup type is used. The GPS device 40 receives radio waves transmitted from satellites, detects the current position based on the radio wave information, and functions as means for detecting the position of the vehicle. As a means for detecting the position of the vehicle, other devices may be used instead of the GPS device 40. For example, a magnetic sensor that detects magnetic markers embedded at regular intervals along the road surface may be used. The radar sensor 45 and the image sensor 46 function as means for detecting other vehicles in the platoon and other vehicles outside the platoon or other obstacles. Detect direction and running speed.

  The vehicle is provided with a road-vehicle communication unit 42. The road-vehicle communication unit 42 communicates with the loop antenna A embedded in the road surface to communicate traffic information, weather information, and the like. For example, a communication device that communicates using radio waves as an information transmission medium is used. The loop antenna A in the road surface is connected to a road-vehicle communication device 90 provided as an infrastructure facility. In the vehicle travel control device, the installation of the road-vehicle communication unit 42 may be omitted.

  A vehicle-to-vehicle communication unit 43 is provided in the vehicle. The inter-vehicle communication unit 43 performs inter-vehicle communication for communicating with other vehicles, and communicates vehicle information such as the current position of the vehicle, a target speed pattern, and a control target position with each other.

Next, row running by the vehicle running control device according to the present embodiment will be described. FIG. 2 is a flowchart showing a processing procedure using the vehicle group center of gravity according to the first embodiment, and FIG. 3 is a plan view of a row running using the vehicle group center of gravity. The process shown in FIG. 2 is repeatedly executed by the ECU 10 at a predetermined cycle (for example, 50 ms). As shown in FIG. 3, the vehicles B ₁ , B ₂ , B ₃ and B ₄ travel along the road 61 in a row according to the vehicle travel control of the travel control system, forming one vehicle group. . Each of the vehicles B _{1 to} B ₄ is equipped with the vehicle travel control device 1 according to the present embodiment, and the vehicle's current position, vehicle speed, and target control position are detected by the inter-vehicle communication unit 43 of each vehicle travel control device 1. The vehicle information such as the target speed pattern and the distance between other vehicles is communicated with each other.

  In the process described below, it is not necessary that the vehicle travel control device 1 of the present embodiment is mounted on all the vehicles forming the platoon, and the vehicle of the present embodiment is mounted on at least one of the vehicles forming the platoon. It is sufficient if the traveling control device 1 is mounted. In addition, the following calculation processing related to control is performed by a vehicle travel control device mounted on one vehicle forming a platoon representing the platoon, and other vehicles follow the calculation processing result. In this case, there is no relation between the vehicle on which the traveling vehicle control device that performs the arithmetic processing is mounted and the order in which the traveling plan is generated in the vehicle platoon, and the vehicle on which the vehicle traveling control device that performs the arithmetic processing is mounted The travel plan may be generated first or may be generated last. Preferably, a vehicle travel control device for a vehicle equipped with a device having the highest processing capability in the platoon may perform the arithmetic processing on behalf of the platoon.

Further, when traveling in a row like the vehicles B ₁ , B ₂ , B ₃ and B ₄ , it is desirable that the distance between the vehicles is short. That is, by shortening the inter-vehicle distance, it is possible to prevent interruption of another vehicle to the platoon and improve driving safety. Moreover, the traveling air resistance of the rear traveling vehicle can be reduced, and fuel consumption can be reduced.

As shown in FIG. 2, in the convoy travel in this embodiment, the vehicle group center of gravity of the convoy is first calculated by the ECU 10 of the vehicle equipped with the vehicle travel control device 1 that performs the arithmetic processing (S11). The vehicle group center of gravity is the distance between the vehicles acquired by the GPS device 40, the radar sensor 45, and the image sensor 46 mounted on each vehicle B ₁ , B ₂ , B _3, and B ₄ , and each vehicle. It is calculated from the vehicle weight. That is, the center of weight of the vehicle group is centered on a point that is balanced as the center of weight when the entire platoon is placed on a large table as it is. For example, in the example shown in FIG. 3, since the vehicle weight of the vehicle B ₂ is heavier than the vehicle B ₃ , the vehicle group center of gravity G is between the vehicles B ₂ and B ₃ and is slightly positioned from the vehicle B _2. It becomes.

Next, the order in which a travel pattern (travel plan) is generated among the vehicles B ₁ , B ₂ , B ₃ and B ₄ forming the vehicle group is determined (S12). The travel pattern is generated in order from a vehicle close to the center of gravity of the vehicle group, which is a vehicle having the lowest degree of freedom in determining the travel pattern. In the example illustrated in FIG. 3, the travel pattern is determined in the order of the vehicle B ₂ , the vehicle B ₃ , the vehicle B ₁ , and the vehicle B _{4 from} the order close to the vehicle group center of gravity G.

  In this case, when the weight of each vehicle forming the vehicle group cannot be acquired, the vehicle information obtained by the inter-vehicle communication unit 43 may be used for estimation. Alternatively, the running pattern may be determined in the order close to the midpoint of the straight line connecting the front end of the first vehicle and the rear end of the last vehicle without calculating the vehicle group center of gravity using the weight of the vehicle. . Furthermore, if it is difficult to measure the positional relationship between the vehicles belonging to the vehicle group due to bad weather, etc., the travel plans are simply made in order from the vehicle with the smallest sum of the distance between the front vehicle and the distance between the rear vehicle. You may make it produce | generate.

Generating a running pattern of the vehicle B ₂ first generate a running pattern (S13). Running pattern of the determined vehicle B ₂ is transmitted to the other vehicles in the vehicle group by the vehicle travel control device 1 vehicle inter-vehicle communication unit 43 that is mounted to perform the calculation processing (S14). Next, travel patterns of the vehicle B ₃ , the vehicle B ₁ , and the vehicle B ₄ are generated in order based on the travel pattern of the already generated vehicle, and the generated travel pattern is transmitted to other vehicles in the vehicle group, It repeats until the running pattern of all the vehicles is generated (S15).

  According to the vehicle travel control device of the present embodiment, the ECU 10 of the vehicle travel control device 1 surrounds the front and the rear by at least one of the vehicle forming the platoon and the vehicle not forming the platoon. In order to generate a travel plan in order from the vehicle that is, the comparison that the front and rear are not surrounded by other vehicles after making a travel plan preferentially from vehicles that may collide with the front vehicle and the rear vehicle Therefore, it is possible to further improve the safety of the vehicles of the entire platoon because the travel plan of the safe vehicle is made.

  In particular, in the present embodiment, a travel plan is generated in order from the vehicle closest to the center position in the platoon, and the center position in the platoon is calculated from the weight of each vehicle forming the platoon and the inter-vehicle distance between the vehicles. Since it is the center of gravity of the platoon, a travel plan is preferentially created from vehicles with high risk of rear-end collisions in places where heavy vehicles are congested, and a travel plan that matches the situation of each vehicle is generated And the safety of the entire vehicle group can be secured.

  Furthermore, in this embodiment, when it is difficult to measure the positional relationship between the vehicles belonging to the vehicle group due to bad weather or the like, the vehicle with the smallest sum of the inter-vehicle distance with the front vehicle and the inter-vehicle distance with the rear vehicle is in order. A travel plan can also be generated, and a travel plan can be preferentially created from vehicles with a high possibility of rear-end collision, so that it is possible to generate a travel plan that suits the situation of each vehicle, and to improve the safety of the entire vehicle group It can be secured.

  Alternatively, in this embodiment, without using the weight of the vehicles forming the vehicle group, the center position in the platoon is set as the midpoint of a straight line connecting the front end of the leading vehicle and the rear end of the last vehicle, A travel plan can be generated in order from the vehicle closest to the midpoint, and the center position in the platoon is determined based only on the positional relationship of the vehicles in the platoon, which has the advantage of facilitating calculations.

  Hereinafter, a second embodiment of the present invention will be described. FIG. 4 is a flowchart showing a processing procedure using the safety margin according to the second embodiment, and FIG. 5 is a plan view of the row running using the safety margin. In the present embodiment, a safety margin, which is an index related to safety, is calculated from the inter-vehicle distance and relative speed between each of the vehicles forming the platoon and either of the front and rear vehicles, and a travel plan is calculated in order from the vehicle with the lowest safety margin. The point of generation is different from the first embodiment.

As shown in FIG. 4, in platooning according to the present embodiment, a safety margin with the vehicles in the vehicle group is calculated by the ECU 10 of the vehicle on which the vehicle traveling control device 1 that performs arithmetic processing is mounted (S21). The safety margin is calculated by calculating the required distance from the vehicle speed of each vehicle in the vehicle group and dividing the distance between the vehicles at that time by the required distance as the safety margin. In the example of FIG. 5, for example, a vehicle d ₁ of the vehicle B1 and vehicle B2, calculates a safety margin based on the vehicle B1 and vehicle B2 each vehicle speed. In this case, the necessary distance between the vehicles is set so that the rear-end collision in the platoon can be avoided even in the event of a worst-case scenario such as simultaneous occurrence of malfunctions, and the effect of improving fuel efficiency by reducing air resistance can be obtained. .

  For example, during acceleration and steady running, for a preceding vehicle, when an immediate stop is started due to a failure, the control position at the time of occurrence of an emergency stop is the farthest in the error range with respect to the target position at that time. For the following vehicle (following vehicle), the control position is set to the target position at the time of the emergency stop of the preceding vehicle in consideration of the case where the emergency stop start speed is the lowest within the error range. On the other hand, it is the most forward position in the error range, the emergency stop start speed is the lowest in the error range, and the necessary inter-vehicle distance is set considering the case where communication failure occurs simultaneously from the start of communication when the preceding vehicle has failed The

  On the other hand, during deceleration, in the case of a preceding vehicle, as in acceleration and steady running, when an immediate stop is started due to a failure, the control position at the time of emergency stop is relative to the target position at that time. In the case of a follower vehicle, the control position is the target of the time at the time of the emergency stop occurrence of the preceding vehicle in consideration of the case where it is the rearmost position in the error range and the emergency stop start speed is the lowest in the error range Necessary inter-vehicle pattern considering the case where the position is the farthest in the error range with respect to the position, the emergency stop start speed is the lowest in the error range, and communication failure occurs simultaneously from the start of the failure occurrence communication of the preceding vehicle Is set.

  Alternatively, the safety margin can be calculated in order from a vehicle having a shorter collision time (TTC: Time to collision) = (distance between vehicles with surrounding vehicles) / (relative speed in the direction of approaching with surrounding vehicles). You may make it produce | generate.

Next, for a vehicle located at the end of the vehicle group, a safety margin with a vehicle outside the vehicle group is obtained in the same manner (S22). For example, in the case of vehicles B4 shown in FIG. 5, the inter-vehicle distance d ₂ between the vehicle group outside the vehicle C1, calculating a safety margin based on the vehicle B4 and vehicle group outside the vehicle C1 each vehicle speed.

Further, a safety margin is similarly obtained in the horizontal direction (S23). For example, in the case of vehicles B4 shown in FIG. 5, calculates the lateral vehicle distance d ₃ between the vehicle group outside the vehicle C2, a safety margin based on the vehicle speed in the lateral direction of each vehicle B4 and vehicle group outside the vehicle C2 To do.

  The ECU 10 of the vehicle on which the vehicle travel control device 1 that performs the arithmetic processing is mounted has a safety margin with the vehicles inside and outside the vehicle group for each of the vehicles B1, B2, B3, and B4 calculated as described above. The minimum safety margin is selected as the minimum safety margin of the vehicle (S25). Further, the ECU 10 of the vehicle travel control device 1 generates a travel pattern in order from the vehicle having the smallest minimum safety margin (S26).

In the subsequent processing, similarly to the first embodiment, the travel patterns of the vehicle B ₃ , the vehicle B ₁ , and the vehicle B ₄ are sequentially generated based on the travel pattern of the vehicle that has already been generated, and the generated travel is performed. The pattern is transmitted to other vehicles in the vehicle group, and is repeated until the traveling patterns of all the vehicles are generated (S27, S28).

  According to this embodiment, the ECU 10 of the vehicle travel control device 1 calculates a safety indicator, that is, a safety margin, from the inter-vehicle distance and the relative speed with respect to either the front or rear vehicle of each vehicle forming the platoon. In order to generate a travel plan in order from the vehicle with the lowest safety margin, for example, even if it is a vehicle that is approaching a vehicle outside the platoon, Regardless of the relationship, a travel plan is preferentially set for the vehicle, and a travel plan suitable for the situation of each vehicle can be generated. That is, even when the leading vehicle or the last vehicle in the platoon is approaching a vehicle outside the platoon, the safety of the least safe vehicle can be secured, and the entire vehicle group has a safe driving pattern. It can be generated, increasing the safety of the entire traffic flow.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made. In the present embodiment, the case where the traveling control system of the present invention is applied to an in-vehicle vehicle traveling control apparatus has been mainly described, but the traveling control system of the present invention is not limited to this. For example, an aspect in which a vehicle travel control device that controls the travel control system of the present invention is installed in a facility outside the vehicle, and vehicles that form a platoon according to a command from the vehicle travel control device is controlled from the outside is also within the scope of the present invention. included.

1 is a schematic configuration diagram of a vehicle travel control device according to a first embodiment. It is a flowchart which shows the process sequence using the vehicle group gravity center which concerns on 1st Embodiment. It is a top view of platooning using a vehicle group center of gravity. It is a flowchart which shows the process sequence using the safety margin which concerns on 2nd Embodiment. It is a top view of platooning using a safety margin.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vehicle travel control apparatus, 10 ... ECU, 30 ... Engine, 32 ... Throttle actuator, 34 ... Brake device, 36 ... Brake actuator, 40 ... GPS apparatus, 41 ... Wheel speed sensor, 42 ... Road-to-vehicle communication part, 43 ... Vehicle-to-vehicle communication unit, 44: steering motor, 45 ... radar sensor, 46 ... image sensor, 61 ... road, 90 ... road-to-vehicle communication device, B1, B2, B3, B4 ... vehicle, C1, C2 ... vehicle outside vehicle group, G ... vehicle group center of _{gravity, d 1, d 2, d} 3 ... vehicle-to-vehicle distance.

Claims (6)

A travel control system that forms a platoon with a plurality of vehicles and travels the vehicles,
Travel plan generating means for generating a travel plan for each vehicle forming the platoon,
The travel plan generation unit generates the travel plan in order from a vehicle that is enclosed in front and rear by at least one of a vehicle that forms the platoon and a vehicle that does not form the platoon. A traveling control system.   The travel control system according to claim 1, wherein the travel plan generation unit generates the travel plan in order from a vehicle having a smaller sum of an inter-vehicle distance with a preceding vehicle and an inter-vehicle distance with a rear vehicle.   The travel control system according to claim 1, wherein the travel plan generation unit generates the travel plan in order from a vehicle close to a center position in the platoon.   4. The travel control system according to claim 3, wherein the center position in the row is a center of gravity of the row calculated from the weight of each vehicle forming the row and the inter-vehicle distance between the vehicles.   4. The travel control system according to claim 3, wherein the center position in the row is a midpoint of a straight line connecting a front end of a leading vehicle and a rear end of the last vehicle in the row.   The travel plan generation means calculates an index related to safety from the inter-vehicle distance and relative speed with either the front or rear vehicle of each vehicle forming the platoon, and sequentially from the vehicle with the lowest safety according to the index. The travel control system according to claim 1, wherein the travel control system generates a travel plan.

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