1. Field of the Invention
This invention relates to a vehicle travel control system which controls the travel of a plurality of unmanned or manned vehicles.
2. Description of the Related Art
In extensive mine sites and the like, it is necessary to convey ore one way over several tens of kilometers by means of dump trucks. In this type of industry, the use of unmanned vehicles has become widespread. Position measuring devices such as GPS (Global Positioning System) are provided in the vehicles and this position measuring device is used to compare continuously the position measured using the position measuring device and the recorded course data and the two are adjusted so that they correspond. By this means, the unmanned vehicle travels along the predetermined course.
Apart from the unmanned vehicles (dump trucks), there are various types of service vehicles on the travel track in an extensive mine site such as graders and water sprinklers, conveying vehicles carrying excavators, and light vehicles conveying operators and performing maintenance operations.
The velocity of these various types of vehicle varies to a great extent. Vehicles such as graders have an extremely low velocity of approximately 7 km while they are operating, while vehicles such as dump trucks and light vehicles travel at a high velocity (of the order of 50 km). For this reason, the low-velocity vehicles constitute an obstacle for the high velocity vehicles. In addition, vehicles which have broken down ahead and fallen rocks and the like also constitute obstacles.
For this reason, when there is a grader ahead of a dump truck (unmanned vehicle) performing repair operations at extremely low velocity, and there is a broken down vehicle or fallen rock or the like ahead of the dump truck (unmanned vehicle) there is no choice but to interrupt the conveying operations using the dump trucks until the grading operations have been completed or the obstacle has been removed. Interrupting the conveying operations reduces the operating efficiency. In particular, in seasons when there is a lot of rain, it is necessary to perform grading operations with rapid succession and the reduction in the operating frequency is felt keenly.
In the prior art, various inventions have been applied for patents and publicized in which, when there is an obstacle ahead of a unmanned vehicle, the obstacle is detected with an obstacle detector and on the basis of this detection a track permitting the obstacle to be avoided is sought and that evasive track is adopted.
For example, Japanese Patent Application Laid-Open No. 62-88006 has disclosed an invention in which, if an obstacle has been discovered by means of an obstacle sensor, the direction in which there is no obstacle is determined by changing the direction in which the vehicle is facing and the vehicle is made to move in the direction determined.
In addition, Japanese Patent Application Laid-Open No. 9-269828 discloses an invention in which, if there is an obstacle ahead of a unmanned vehicle, the vehicle is made to travel along a guide provided on the underlying surface, and if an obstacle is detected by means of sensors, a bypass track away from the guide is determined and the unmanned vehicle is made to move along this bypass track.
However, these technologies are based on the presumption that there are sufficiently extensive, level areas on which the unmanned vehicle can travel to the side of the path on which it travels in such covered travel tracks over short distances. In outdoor industrial facilities such as mines where the travel track distances extend in one direction over an as long stretch as several tens of kilometers and it is not possible to ensure that there are flat and sufficiently large areas for vehicles to pass etc., it is not possible to apply such technology as it is.
In addition, for example, even if it were possible to provide passing level areas on both sides of the travel track, there is the fear that the side of the track will collapse under the weight of large dump trucks. In fact, when laden the dump trucks"" weight exceeds 200 t. For this reason, when vehicles pass on the shoulder of the track which is fragile and has not been maintained, there is also the risk that the tires will become stuck and in the worst case the vehicles may slip of the track and fall. In addition, there is the problem of correctly implementing the means for sensing the state of the surface of the shoulder of the track.
On extensive mine sites, there is generally a 2-way dual lane vehicle track. For this reason, if there is an obstacle present ahead of the vehicle, a system has been devised in which the vehicles are made to pass the obstacle by traveling on the oncoming lane of the track. Because the oncoming lane is maintained, the abovementioned problems such as the risk of getting stuck and of collapse of the shoulder which are due to insufficient maintenance of areas such as the shoulder of the track do not occur. However, as a result of the vehicles being made to travel on the oncoming track, there is the risk of a head on collision.
When there are manned vehicles traveling on the oncoming lane, it is not possible to anticipate when a unmanned vehicle will disrupt the oncoming lane. For this reason, it is difficult to avoid the risk of head-on collisions. In addition, if the oncoming vehicle is also a unmanned vehicle, it is not possible to stop at a safe position after confirming the presence of passing vehicles by means of sensors mounted on the vehicles. This is because the effective detection range of obstacle sensors is limited. After detecting stationary obstacles with an obstacle sensor, it is possible to maintain a sufficient stopping distance and stop safely, but after detecting vehicles traveling at high velocity it is not possible to maintain sufficient stopping distance and stop safely For this reason, it is not possible to avoid the risk of head-on collisions.
In the prior art as mentioned above, when vehicles are made to travel on the oncoming lane in order to avoid obstacles on their original lane, vehicles on the oncoming lane cannot maintain sufficient stopping distance and there is a risk of a head-on collision.
The present invention is designed with the above circumstances in mind, and resolves the first problem by making it possible that when vehicles are made to travel on the oncoming lane in order to avoid an obstacle on their original lane, there is no risk of a head-on collision and the vehicles can pass safely.
In contrast to unmanned vehicles which travel in covered factories and the like, the travel condition of the unmanned vehicles which travel outdoors in places such as mines is changed according to the various external factors.
For example, not only are there sometimes obstacles such as broken down vehicles and fallen rocks on the travel track on which the vehicles are traveling, but also the surface of the travel track is in some cases degraded by rainfall and sprayed water and the effective range of the sensors is shortened. In addition, on a mine site, because the surface on which the vehicles travel is paved, only part of the surface of the track becomes muddy and slippery.
Therefore, in view of such things as the aforementioned changes in the state of the travel track, it is necessary to bring about changes in the travel conditions such as the position and velocity of the vehicles in order to be able to ensure safety.
In extensive industrial sites according to the prior art, if changes are brought about in the travel conditions of the vehicles, the data on the travel conditions of the entirety of the extensive travel tracks has to be updated and this updated data has to be transmitted to all the vehicles.
The radio load when attempting to transmit the data relating to the travel conditions of the entirety of the aforementioned extensive travel tracks becomes extremely large. A method is adopted in which data is transmitted to all the vehicles after all they have all been temporarily stopped. However, the problem with temporarily stopping all the vehicles is that it reduces the production efficiency. In addition, instead of adopting a method in which the vehicles are temporarily stopped, a method is adopted in which data relating to the travel conditions of the entirety of the extensive travel tracks is converted into compact data and transmitted over a long period. However, when compact data is transmitted over long periods, there is a long delay until all the changes to the data are completed. For this reason, there is a safety problem that interference is generated among the vehicles as a result of this delay.
This invention is designed to deal with such a situation, and it resolves the second problem by enabling data to be transmitted quickly when the travel conditions have been set or changed but does not cause the production efficiency to be reduced as a result of all the vehicles being stopped or give rise to a safety problem due to the delay in the data changes.
In some cases manned vehicle travel tracks are temporarily provided in such way that they intersect with the unmanned vehicle travel tracks. In this case, it is necessary to temporarily stop the unmanned vehicles just before reaching that temporarily provided travel track. However, in this case also, data relating to the travel conditions of all the travel tracks of the extensive site has to be updated and this updated data has to be transmitted to all the vehicles.
For this reason, as mentioned above, there is a problem that stopping all the vehicles reduces the efficiency and there is a safety problem due to the delay in the data changes.
The present invention is designed with this situation in mind, and it resolves the third problem by enabling data to be transmitted quickly if it has become necessary to temporarily stop the vehicles, but does not cause the production efficiency to be reduced as a result of all the vehicles being stopped or give rise to a safety problem due to the delay in the data changes.
In order to resolve the aforementioned first problem, a first aspect of the present invention is defined in that a vehicle travel control system in which travel conditions of a travel track made up of 2-way dual-lane vehicle tracks on which a plurality of vehicles travel are monitored by a monitor station, and travel instructions are issued to the plurality of vehicles from the monitor station; comprising
means for setting a no-entry area which, on the basis of the monitored result of the travel conditions of the travel track, sets the no-entry area ahead of one of the vehicles traveling on one lane of the 2-way dual-lane vehicle track;
first instruction means which issues to the one of the vehicles travel instructions which cause the vehicle to avoid the no-entry area and travel on a section of an oncoming lane whose traffic runs in an opposite direction to the one lane; and
second instruction means which issues to an oncoming vehicle traveling on the oncoming lane travel instructions which prohibit entry to the section of the oncoming lane.
In addition, a second aspect of the present invention is defined in that the first aspect of the invention further comprises means for setting a prohibited section in which it is prohibited for one of the vehicles to travel on the oncoming lane; wherein, if the section of the oncoming lane is not the prohibited section, the first instruction means and the second instruction means issue the travel instructions to the one of the vehicles and to the oncoming vehicle.
The first and second aspects of the invention will be explained with reference to FIGS. 6(a) and 6(b).
In the first and second aspects of the invention, no-entry areas E are established ahead a vehicle Jm traveling on one lane of a 2-way dual-lane vehicle track, on the basis of the monitored result of the travel state of the travel track. Then travel instructions are issued to the vehicle Jm traveling on one lane, the travel instructions causing them to avoid the no-entry area E and travel on part of a section L of an oncoming lane, a lane whose traffic runs in the opposite direction to the aforementioned lane. Travel instructions are issued to an oncoming vehicle Jt traveling on the oncoming lane which prohibit entry to the part of the track section L. In this way, even if the vehicle Jm on one lane avoid a no-entry area E ahead of them and travel on the oncoming lane, there is no risk of a head-on collision between the vehicle Jm on one lane and the vehicle Jt traveling on the oncoming lane and they can travel safely.
In addition, in order to resolve the aforementioned second problem, a third aspect of the present invention is defined in that a vehicle travel control system in which travel conditions of a travel track on which a vehicle travels are set by a monitor station and travel instructions corresponding to the travel conditions are issued to the vehicle by the monitor station; comprising
means for setting an upper limit velocity which sets the upper limit velocity on a section of the travel track; and
instruction means for issuing, as the travel instructions to the vehicle, travel conditions including the set upper limit velocity for the section of the travel track;
wherein, when the travel instructions are issued by the instruction means, the vehicle travels on the section of the travel track at a velocity which does not exceed the upper limit velocity.
The third aspect of the invention will be explained with reference to FIG. 4.
In the third aspect of the invention, a velocity limit is set on the section 47 of the track. Then, travel conditions, including the aforementioned upper limit velocity set for the section 47, are issued as travel instructions to the aforementioned vehicle. If travel instructions have been issued to the vehicle, the aforementioned vehicle travels on the section 47 of the aforementioned travel track at a velocity which does not exceed the aforementioned upper limit velocity.
In this way, in the third aspect of the invention, the data transmission load is minimized because the travel conditions are not updated for all the sections of the travel tracks and it is possible to regenerate and transmit, as travel instructions, only travel conditions relating to the section 47. For this reason, when the travel conditions are set or changed it becomes possible to transmit data quickly but the problem of the production efficiency being reduced as a result of all the vehicles being stopped does not arise nor is there a safety problem due to the delay in the data changes.
In addition, a fourth aspect of the present invention is defined in that a vehicle travel control system in which travel conditions of a travel track system on which a vehicle travels are changed by a monitor station and travel instructions corresponding to the changed travel conditions are issued to the vehicle from the monitor station; comprising
travel velocity changing means for changing a travel velocity on a section of the travel track; and
instruction means for issuing, as the travel instructions to the vehicle, travel conditions including the changed travel velocity for the section of the travel track;
wherein, when the travel instructions are issued by the instruction means, the vehicle travels on the section of the travel track at the changed velocity.
The fourth aspect of the invention will be explained with reference to FIG. 4.
In the fourth aspect of the invention, the travel velocity in the section 47 of the travel track is changed. Then, travel conditions including the aforementioned changed travel velocity for the section 47 are issued to the vehicle as travel instructions. If travel instructions are issued, the vehicle travels on the section 47 at a changed velocity.
In this way, in the fourth aspect of the invention, the data transmission load is minimized because the travel conditions are not updated for all the sections of the travel tracks and it is possible to regenerate and transmit, as travel instructions, only travel conditions relating to the section 47. For this reason, when the travel conditions have been set or changed it becomes possible to transmit data quickly but the problem of the production efficiency being reduced as a result of all the vehicles being stopped does not arise nor is there a safety problem due to the delay in the data changes.
In addition, a fifth aspect of the present invention is defined in that a vehicle travel control system which is applied to a travel track on which a vehicle slips in accordance with a lateral acceleration applied in a lateral direction relative to a direction of travel of the vehicle, and in which travel conditions for the travel track on which the vehicle is traveling are set by a monitor station and travel instructions corresponding to the travel conditions are issued to the vehicle by the monitor station; comprising
lateral acceleration setting means for setting an upper limit value for the lateral acceleration on a section of part of the travel track; and
instruction means for issuing, as the travel instructions to the vehicle, travel conditions including an upper limit velocity corresponding to the lateral acceleration for the section of the part of the travel track;
wherein, when the travel instructions are issued by the instruction means, the vehicle travels on the section of the travel track at a velocity not exceeding the upper limit velocity.
The aforementioned fifth aspect of the invention will be explained with reference to FIG. 4.
In the fifth aspect of the invention, an upper limit value is set for the lateral acceleration on the section 47 of the travel track. Then, travel conditions including an upper limit velocity corresponding to the aforementioned lateral acceleration for the aforementioned section are issued as travel instructions to the vehicles. If travel instructions. are issued, the vehicle travels on the section 47 of the aforementioned travel track at a velocity not exceeding the aforementioned upper limit velocity.
In this way, in the fifth aspect of the invention, the data transmission load is minimized because the travel conditions are not updated for all the sections of the travel tracks and it is possible to regenerate and transmit, as travel instructions, only travel conditions relating to the section 47. For this reason, when the travel conditions have been set or changed it becomes possible to transmit data quickly but the problem of the production efficiency being reduced as a result of all the vehicles being stopped does not arise nor is there a safety problem due to the delay in the data changes.
In addition, a sixth aspect of the present invention is defined in that a vehicle travel control system in which travel conditions of a travel track system on which a vehicle travels are set by a monitor station and travel instructions corresponding to the travel conditions are issued to the vehicle by the monitor station, comprising:
means for setting a stopping point which sets at one point on the travel track a stopping point at which the vehicle is supposed to stop traveling; and
instruction means for issuing, as the travel instructions to the vehicle, travel conditions including the stopping point,
wherein when the travel instructions are issued by the instruction means, the vehicle stops at the stopping point.
The aforementioned sixth aspect of the invention will be explained with reference to FIG. 4.
In the sixth aspect of the present invention, a stopping point at which the vehicle is supposed to stop traveling is defined at a certain point 49 on the travel track. Then, travel conditions including the aforementioned stopping points 49 are issued to the vehicle as travel instructions. If travel instructions have been issued, the vehicle stops traveling at a stopping point 49.
In the sixth aspect of the invention, the data transmission load is minimized because the travel conditions are not updated for all the sections of the travel tracks and it is possible to regenerate and transmit, as travel instructions, only travel conditions relating to a certain stopping point 49. For this reason, it becomes possible to transmit data quickly when it becomes necessary to stop the vehicle temporarily but the problem of the production efficiency being reduced as a result of all the vehicles being stopped does not arise nor is there a safety problem due to the delay in the data changes.
A seventh aspect of the present invention is defined in that if, in the aforementioned third to sixth aspects of the invention, when the travel instructions are issued by the instruction means, the vehicle gradually decreases a travel speed so as to reach a velocity instructed for the section or so as to stop traveling at the stopping point.
In the seventh aspect of the invention, if travel instructions are issued to the aforementioned vehicle, the travel velocity is gradually decreased until the velocity stipulated in the instruction is reached. In addition, the travel velocity is gradually decreased until the vehicle stops at the stopping point 49. This makes it possible to prevent the vehicle rolling over and the like.