Method and system for controlling a plurality of vehicles as a group unit

Abstract: When a joining vehicle group (10) operated in higher density by a moving target system under vehicle-to-vehicle control approaches to a joining location, a joining MT1 is allocated to only a head vehicle of the joining vehicle group. A head MT2 in a continuous null MT group on a main road (6) greater in length than the joining vehicle group is set, as an MT (21) on the main road, in synchronism with the joining MT1 and, by doing so, vehicle joining is achieved.

Description: The present invention relates to a method and system for automatically controlling, as a group unit, a plurality of vehicles running on a running road. The moving target method (hereinafter referred to as an MT method) is conventionally known as a method for automatically controlling running vehicles on a running road. A system using such an MT method comprises, as shown in FIG. 1, a group of position information equipment 73 for detecting the position and speed of running vehicles, a running control computer 75 for performing the management, control, etc., of the running vehicles on the basis of information on the position detected by the position information equipment 73, and a communication equipment 74 for conducting communication by providing information from the computer 75 to the running vehicle, transmitting a control instruction, and obtaining information from the running vehicle. The MT method is a control method for, as shown in FIG. 2, setting an imaginary running path 800 on the running control computer 75 equivalent to an actual running road (real road), setting a point (moving target hereinafter referred to as an MT) ideally running at a predetermined interval and speed on the imaginary running path 80, or at a vehicle-to-vehicle distance and running speed matching to the meteorological condition such as the falling of snow or frozen surface of a road, and enabling a real vehicle to run in a way to follow the MT. In this case, there exist, as shown in FIG. 2, an MT (null MT) 720 not allocated to the running vehicle and MT (not-null MT) 721 allocated to the running vehicle. As in an example of FIG. 1, an MT (main road MT) 72 is generated on a main road 76 at a predetermined interval and speed and the MT72 is allocated to a vehicle entering a vehicle control section 78. An MT72 (corres. to the MT720 in FIG. 2) not allocated to the vehicle is moved as a null MT72 on the main road 76. A joining MT71 corresponding to the MT72 on the main road 76 is generated on a branch road 77. The MT71 is allocated to a respective vehicle (joining vehicle) entering the branch road 77. Further, the null MT72 on the main road 76 corresponds to the joining MT71 allocated to the joining vehicle and is handled as the MT72 on the main road. The joining MT71 allocated to the joining vehicle is set in synchronism with the MT72 on the main road, so that vehicle joining is achieved at a joining point. It is to be noted that the MT71, being not allocated to the vehicle, moves as the null MT71 (corres. to the MT720 in FIG. 2) on the branch road 77. Further, as the method for controlling running vehicles there is a vehicle-to-vehicle control method. The vehicle-to-vehicle control method comprises setting a vehicle-to-vehicle detection sensor such as a radar for detecting a distance between individual vehicles and running a given vehicle in a way to keep a predetermined distance relative to a preceding vehicle on the basis of the vehicle-to-vehicle distance detected by the sensor. It is possible to control a plurality of vehicles as a group by combining a vehicle-to-vehicle communication with such vehicle-to-vehicle control. In the conventional technique using the MT method, however, it is necessary to apply the MT to each vehicle. The interval between the MTs is generally set somewhat greater among various kinds of vehicles so as to provide ample safety even if there is a difference in vehicle length and in braking capability. At vehicle joining, there was some restriction in number of running vehicles per given interval length and hence some restriction in high density/high effective vehicle joining control. Under the vehicle-to-vehicle control it is possible to increase the number of running vehicles per given section length in comparison with the MT method. For the application of the conventional MT method to the vehicle-to-vehicle control, however, it is necessary to constantly follow the MT so as to be matched to a corresponding vehicle under the vehicle-to-vehicle control. For this reason, the load of a computer necessary to calculate the position, speed, etc., of the MT cannot be ignored. Further, there was also the problem of how effectively the MT of a vehicle running on the main road should be controlled. It is accordingly the object of the present invention to provide a method and system for controlling a running vehicle group, which enable a running vehicle from a branch road to be joined onto the main road in high density and high efficient way. In order to solve the above-mentioned task, there is provided a running vehicle group controlling method for automatically controlling a plurality of vehicles running on a running road which comprises the steps of: allocating only a head vehicle of a joining vehicle group (a joining vehicle group controlled as a unit under vehicle-to-vehicle control for keeping a vehicle-to-vehicle distance constant) approaching from a branch road and joining onto a main road under vehicle-to-vehicle control, and joining on a main road, to a joining MT; and, when a length of a continuous null MT group on the main road is longer than that of the joining vehicle group, handling the head MT of the null MT group as a joining MT on the main road, setting the joining MT in synchronism with the joining MT on the main road and, by doing so, achieving vehicle joining on the main road. Here, the control above is conducted by mounting a vehicle-to-vehicle detection sensor for detecting a vehicle-to-vehicle distance relative to a preceding vehicle to each of joining vehicle groups and effecting communication (road/vehicle communication) via communication equipment on the basis of the vehicle-to-vehicle distance detected by the vehicle-to-vehicle sensor as well as data (position/speed data of the running vehicle) from a communication (vehicle/vehicle communication) between the vehicles and/or position information equipment installed on the running roads. Further, according to the present invention, when the length of a continuous null MT group on the main road is shorter than that of a joining vehicle group, the joining vehicle group is divided into a plurality of vehicle groups so as to make the length of the joining vehicle group smaller than that of the null MT group; a joining MT is allocated to a respective divided joining vehicle group; and a head MT of the null MT group is handled as an MT on the main road and the joining MT is sequentially set in synchronism with the MT on the main road and, by doing so, vehicle joining is achieved. In the running vehicle group controlling method, an MT is generated on the main road at predetermined interval and moving speed and the MT is allocated to any vehicle approaching to a vehicle control section. The MT not allocated to the vehicle is handled as a null MT and a length is found on the continuous null MT group (null Mt group). Since the vehicle group (joining vehicle group) joining from the branch road onto the main road is obeyed under vehicle-to-vehicle control for keeping the vehicle-to-vehicle distance constant, and the length (joining vehicle group length) of the joining vehicle group can be found as follows: The length of the joining vehicle group = where An: the length of an N-th vehicle in the joining vehicle group; B: the vehicle-to-vehicle length; and N: the number of vehicles in the joining vehicle group. Here, in the case where the length of the null MT group is greater than that of the joining vehicle group, a joining MT is allocated to only a head vehicle in the joining vehicle group. And the head MT in the null MT group is handled as an MT on the main road and the joining MT is set in synchronism with the MT on the main road and, by doing so, vehicle joining is achieved. In the case where the length of the null MT group is shorter than that of the joining vehicle group, the joining vehicle group is divided into a plurality of new joining vehicle groups so as to make the length of the joining vehicle group shorter than that of the null MT group. And the joining MT is allocated to only a head vehicle in the respective new vehicle group. In order to be matched to the respective joining MT allocated to the head vehicle, the new joining vehicle group handles a head MT in the null MT group on the main road as an MT on the main road and sets it in synchronism with the MT on the main road and, by doing so, vehicle joining is achieved. This summary of the invention does not necessarily describe all necessary features so that then invention may also be a sub-combination of these described features. This invention can be more fully understood from the following detailed description when taken in conjunction with the accompanying drawings, in which: FIG. 1 is a view showing an arrangement of a conventional system using an MT method; FIG. 2 is a view for explaining the MT method; FIG. 3 is a view diagrammatically showing a running vehicle group controlling method according to one aspect of the present invention; FIG. 4 is a view showing an arrangement of an on-road system for achieving vehicle-to-vehicle control using the system of FIG. 3; FIG. 5 is a view showing an on-vehicle system for realizing vehicle-to-vehicle control using the system; FIG. 6 is a view for explaining a running vehicle group controlling operation in the system above; FIG. 7 is a view for explaining a running vehicle group controlling operation when the length of a null MT group is shorter than that of a joining vehicle group in the system; and FIG. 8 is a model view for explaining, in more detail, the control operation of a running vehicle group in the example of FIG. 7. An embodiment of the present invention will be explained below with reference to the accompanying drawing. FIG. 3 is a diagrammatic view showing a system using a running vehicle group controlling method according to one aspect of the present invention. The present system uses an MT method and has an arrangement necessary to detect the positions of vehicles on roads (main road 6, branch road 7) and allocate an MT (MT2 on a main road, MT1 on a branch road) to an associated vehicle. That is, the present system relating to the MT method comprises a group of position information equipment 3 set on the running roads and detecting the position and speed of the running vehicles 100, a running control computer 5 for effecting the control, management, etc., of the running vehicles on the basis of information on the positions detected at the position information equipment 3, and a communication equipment 4 for providing information from the computer 5 to the running vehicles, transmitting control instructions and conducting communications for obtaining information from the running vehicles. It is to be noted that, for brevity in explanation, the "joining" aspect of the vehicle is explained in connection with FIG. 3 but that the same thing can also be said about a "branching aspect" of a vehicle. FIG. 4 shows an arrangement of an on-road system for achieving vehicle-to-vehicle control with the use of the present system. Here the vehicle-to-vehicle control is done under which, with a vehicle-to-vehicle sensor 80 such as a radar mounted on the vehicle 100, the vehicle 100 can run in a way to be kept at a predetermined distance (vehicle-to-vehicle distance) relative to a preceding vehicle on the basis of the vehicle-to-vehicle distance detected by the sensor 80 and a group of vehicles can run as one unit in a way to be kept at such a predetermined distance. The vehicle-to-vehicle control is accomplished both with the use of the vehicle-to-vehicle distance detected by the sensor 80 and through the utilization of a communication (hereinafter referred to as a vehicle/vehicle communication) 91 between the vehicle and the adjacent vehicle or a communication (hereinafter referred to as a road/vehicle communication) 92 made on data items (data items on the position and speed of the running vehicle) from the position information equipment 3 via the communication equipment 4. FIG. 5 shows an arrangement of an on-vehicle system for realizing the vehicle-to-vehicle control. As shown in FIG. 5, the vehicle 100 has the vehicle-to-vehicle sensor 80 so as to detect the vehicle distance relative to the preceding vehicle and includes vehicle/vehicle communication device 81 for conducting the vehicle/vehicle communication 91, a road/vehicle communication device 82 for conducting a communication (road/vehicle communication) 92 between itself and the running control computer 5 via the communication equipment 4, and a vehicle-to-vehicle device 82. The vehicle-to-vehicle control device 83 is connected to the vehicle-to-vehicle detection sensor 80, vehicle-to-vehicle communication device 81 and road/vehicle communication device 82. And data items are passed between a drive device 84 and these associated devices. With reference to FIG. 6, an explanation will be given below about the control operation of the vehicle group in the system thus arranged. First, an MT (MT on the main line) 2 is generated by the running control computer 6 on the main road (imaginary running line equivalent to the main road set on the running control computer in FIG. 3) 2 at a predetermined interval and moving speed. When the vehicle 100 running on the main road 6 approaches to a given vehicle control section 8 set near a joining point between the main road 6 and the branch road 7, the running control computer 5 allocates the MT2 to the approaching vehicle. An MT2 not imparted to the vehicle moves as a null MT2 on the main road 6. When, on the other hand, a group of vehicles 10 to be controlled under vehicle-to-vehicle control approaches to the branch road 7, the running control computer 5 allocates an MT (joining MT) 1 to only a head vehicle in the group of vehicles (joining vehicle group). At this time, the running control computer 5 calculates a length of the joining vehicle group, 10, as follows: The length of joining vehicle group = where An: the length of an N-th vehicle in the joining vehicle group; B: the vehicle-to-vehicle distance; and N: the number of vehicles in the joining vehicle group. In the case where the length of a group (group of null MTs) 40 of null MTs (MTs on the main road) continuously moving on the main road 6 is longer than the calculated length of the group of the joining vehicles, the running control computer 5 handles the head MT2 of the MT group 40 as an MT on the main road. The running control computer 5 allows the joining MT1 which is allocated to the head vehicle of the joining vehicle group 10 to synchronize with, and follow, a corresponding MT21. At this time, the respective vehicle in the joining vehicle group 10 is vehicle-to-vehicle controlled. Therefore, in spite of the joining MT1 being not allocated to other than the head vehicle of the joining vehicle group 10, it is possible to effect stable joining of the subsequent vehicle in the vehicle group. In the running vehicle group controlling method, if the above-mentioned condition is not met, that is, if the length of the null MT group is shorter than that of the joining vehicle group, a wait is required until a null MT group satisfying the length of the joining vehicle group arrives. This leads to a time loss. With reference to FIGS. 7 and 8 an explanation will be given below about the running vehicle group control under which, even if the length of the null MT group is shorter than that of the joining vehicle group, it is not necessary to wait for a null MT group satisfying the length of the joining vehicle group. First, the running control computer 5 in FIG. 3 finds the lengths of null MT groups 40A, 40B, ···, that is, continuous null Mt2 groups divided by a corresponding vehicle (on the main road) as shown in FIG. 7. Further, the running control computer 5 divides the joining vehicle group 10 which approaches to the branch road 7 into a plurality of joining vehicle groups so as to make the length of the joining vehicle group shorter than that of the found null MT group. That is, the joining vehicle groups are reorganized. Here, it is assumed that, as shown in FIG. 8, the lengths MTA, MTB, MTC ··· of the null MT groups 40A, 40B, 40C, ··· are found and that the joining vehicle group 10 is divided into joining vehicle groups 10A, 10B, 10C ···. After such a division, the running control computer 5 allocates a joining MT1 to only a head vehicle in the respective joining vehicle groups 10A, 10B, 10C ···. First with respect to the joining vehicle group 10A, the running control computer 5 handles a head MT2 of the null MT group 40A as a corresponding MT21 on the main road and sets the joining MT1 of the joining vehicle group 10A in synchronism with a corresponding MT21 on the main road, so that vehicle joining is achieved. Also with respect to a subsequent joining vehicle group 10B, the running control computer 5 handles a head MT2 of a subsequent null MT group 40B as a corresponding MT21 on the main road and sets joining MT1 of the joining vehicle group 10B in synchronism with the corresponding MT21 to achieve vehicle joining. In the same procedure as will be set out above, safe joining is achieved for all joining vehicle groups divided. According to the present invention as set out above in more detail, for the joining vehicle groups under highly densely operated vehicle-to-vehicle control, a joining MT is allocated only to the head vehicle and a head MT of a continuous null MT group greater in length than the joining vehicle group is handled as a corresponding MT on the main road and the joining MT is set in synchronism with the corresponding MT. By doing so it is possible to achieve simpler but high-efficient joining without allocating a joining MT to every vehicle and disturbing vehicle-to-vehicle control. According to the present invention, in the case where any null MT group is not greater in length than the joining vehicle group, the length of a joining vehicle group is so divided as to be matched to that of the null MT group and, by doing so, the joining vehicle group is reorganized. It is, therefore, possible to achieve still higher-efficient vehicle joining without allocating a joining MT to every vehicle, disturbing the vehicle-to-vehicle control among the vehicle groups and involving any loss time for waiting for a null MT group greater in length than a joining vehicle group.

Claims: A running vehicle group controlling method for automatically controlling a plurality of vehicles (100) running on a running road, characterized by comprising the steps of: when a group of vehicles controlled as a unit under vehicle-to-vehicle control for keeping a vehicle-to-vehicle distance constant approaches from a branch road and joins a main road, allocating a moving target for joining to only a head vehicle in a joining vehicle group (10); and, when a length of a continuous null moving target group (40) on the main road is longer than that of the joining vehicle group (10), setting a head moving target (21) of the null moving target group (40) in synchronism with the moving target (1) for joining and, by doing so, achieving vehicle joining. The method according to claim 1, characterized in that , when the length of the null moving target group (40) is shorter than that of the joining vehicle group (10), the joining vehicle group (10) is divided into groups (10A, 10B) so as to make the length of the joining vehicle group (10) shorter than that of the null moving target group (40) and setting the head moving target of the null moving target group (40), as a moving target (21) on the main road side, in synchronism with the moving target (1) for joining and, by doing so, achieving vehicle joining. A running vehicle group controlling system for automatically controlling a plurality of vehicles running on a running road, characterized by comprising an on-road system (3, 4, 5) installed on the running road and adapted to control the running of the plurality of vehicles on the road in a way to follow a moving target running on an imaginary running road corresponding to the running road and an on-vehicle system (80, 81, 82, 83) installed on the vehicles (100) and adapted to perform vehicle-to-vehicle control of the plurality of vehicles running on the running road, wherein the on-road system (3, 4, 5) and on-vehicle system (80, 81, 82, 83) comprise: means for, when a vehicle group controlled as a unit under vehicle-to-vehicle control for keeping a vehicle-to-vehicle distance constant approaches from a branch road and joins a main road, allocating a moving target (1) for joining to only a head vehicle of a joining vehicle group (10); and means for, when a length of continuous null moving target group (40) on the main road is greater than that of the joining vehicle group (10), setting a head moving target (21) of the null moving target group (40), as the moving target (21) on the main road, in synchronism with the moving target (1) for joining and, by doing so, achieving vehicle joining. The system according to claim 3, characterized in that the on-road system (3, 4, 5) and on-vehicle system (80, 81, 82, 83) further comprise: means for, when a length of the null moving target group (40) is shorter than that of the joining vehicle group (10), dividing the joining vehicle group (10) into joining vehicle groups (10A, 10B) so as to make the length of the joining vehicle group (10) shorter than that of the null moving target group (40), means for allocating a moving target (1) for joining to head vehicles of the joining vehicle groups (10A, 10B), and means for setting the head moving target of the null moving target group (40), as a moving target (21) on the main road, in synchronism with the moving target (1) for joining and, by doing so, achieving vehicle joining. The system according to claim 3, characterized in that the on-road system (3, 4, 5) comprises: a position information equipment group (3) for detecting a position and speed of the running vehicle; a running control computer (5) for effecting a management and control of the running vehicle on the basis of vehicle position information detected by the position information equipment group (3); and a communication equipment (4) for allowing communication to be conducted by providing the information to the running vehicle from the computer (5), transmitting a control instruction and obtaining information form the running vehicle. The system according to claim 3, characterized in that the on-vehicle system (80, 81, 82, 83) comprises: a vehicle-to-vehicle detection sensor (80) for detecting a vehicle-to-vehicle distance relative to a preceding vehicle; vehicle/vehicle communication device (81) for conducting vehicle/vehicle communication; a road/vehicle communication device (82) for conducting road/vehicle communication between itself and the running control computer (5) via the communication equipment (82); and a vehicle-to-vehicle control device (83) connected to the vehicle-to-vehicle sensor (80), vehicle/vehicle communication device (81), road/vehicle communication device (82) and vehicle drive device (84) and adapted to conduct vehicle-to-vehicle control relative to a preceding vehicle.

Inventors: HIGASHI SHINICHI, MATSUMOTO SHINICHI, NAKAGAWA YOSHIROU, SAEKI HIROSHI, HIGASHI, SHINICHI, MATSUMOTO, SHINICHI, NAKAGAWA, YOSHIROU, SAEKI, HIROSHI, Higashi, Shinichi, Mitsubishi Heavy Ind., Ltd., Matsumoto, Shinichi, Mitsubishi Heavy Ind., Ltd., Saeki, Hiroshi, Mitsubishi Heavy Ind., Ltd.
Applicants: MITSUBISHI HEAVY IND LTD, MITSUBISHI HEAVY INDUSTRIES, LTD.
Application year: 1998
Main classification: G08G1
IPC codes: G08G1, B60R21, B60W30