JPH0343846B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle travel control device mounted on each vehicle in a system in which a plurality of vehicles travel as one formation.

Systems are being developed in which vehicles are operated unmanned to transport people or cargo from station to station. In such a transportation system, the operation of vehicles is centrally controlled at a center, and all vehicles run based on instructions from the center. In order to increase the transportation efficiency of the system, it is necessary to operate a large number of vehicles simultaneously and to reduce the distance between the vehicles. However, if we shorten the distance between vehicles and increase the number of vehicles traveling, a huge amount of data must be processed in a short amount of time.
The control equipment installed at the center becomes huge, making economical operation difficult in terms of equipment and maintenance costs.

Therefore, a large number of vehicles are run as a single formation without being physically connected, and only the leading car of each formation is controlled by the center, while the following cars are kept at a constant distance from each other. It is conceivable to perform independent travel control to reduce the control burden at the center. In such a vehicle operation system, since the driving control of the leading vehicle and the driving control of the following vehicles are different, different driving control devices are required for each vehicle. However, if each vehicle is equipped with a separate travel control device depending on the order of the formation, for example, if the lead vehicle is equipped with a travel control device only for driving at the front, that vehicle will be able to function as the lead vehicle. Since it only has the following functions, it becomes impossible to organize vehicles freely.

An object of the present invention is to provide a system in which a plurality of vehicles are operated as one formation and the leading vehicle and the following vehicles are individually controlled.
To provide a vehicle travel control device that enables free vehicle organization and also enables independent travel of one vehicle.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a transport system in which a plurality of vehicles are run as one train without being physically connected. The leading vehicle 1 is controlled to run at a predetermined constant speed, as will be described later. The following vehicle 2 is controlled to maintain a constant inter-vehicle distance from the preceding vehicle. However, all vehicles 1 and 2 have exactly the same configuration. Each vehicle 1, 2 includes an inter-vehicle distance measuring device 3 for measuring the inter-vehicle distance to the preceding vehicle, and an inter-vehicle distance measuring device 3 for assisting in measuring the inter-vehicle distance and, if necessary, for measuring the inter-vehicle distance to the following vehicle. A measuring device 5 and a main control device 4 are provided for determining whether the vehicle is a leading vehicle or a following vehicle and for performing travel control based on this determination. If necessary, each vehicle 1, 2 is equipped with a communication device for transmitting and receiving data to and from the center.

FIG. 2 shows a more detailed configuration of each of the above-mentioned devices. The inter-vehicle distance measuring devices 3 and 5 measure the inter-vehicle distance between two vehicles in succession using ultrasonic waves. The device 3 includes an ultrasonic transmitter 11 and a receiver 12 provided at the front of the vehicle body, and a transmitting/receiving circuit 10. The device 5 includes an ultrasonic transmitter 14 and a receiver 15 provided at the rear of the vehicle body, and a transmitting/receiving circuit 13. The main control device 4 includes two central processing units (referred to as CPUs) 17 and 20, and an acceleration/deceleration drive circuit 22. A microprocessor is preferred as the CPU. The CPU 17 includes the transmitting/receiving circuit 10,
13, calculation of inter-vehicle distance, and determination processing of whether the vehicle is the leading vehicle or the following vehicle. CPU20 is
It performs acceleration/deceleration control and controls the drive circuit 22. These CPUs 17 and 20 are equipped with a ROM 19 that stores their execution programs and a RAM 18 that stores various data. Furthermore, the vehicles 1 and 2 are provided with a vehicle speed detector 23 that detects the running speed of the vehicle and outputs a series of pulses proportional to the running speed. Transmission/reception circuits 10, 13, acceleration/deceleration drive circuit 22, and speed detector 23 are connected to CPUs 17, 20 via interfaces 16, 21, respectively.

A transmitter 11 is driven by the transmitter/receiver circuit 10, and ultrasonic waves having a frequency f1 (for example, 25 KHz) are transmitted forward. When there is a preceding vehicle ahead and this ultrasonic wave is received by the receiver 15, the transmitter/receiver circuit 13 immediately changes the frequency to f2.
Ultrasonic waves (for example, 20 KHz) are transmitted backward from the transmitter 14. When this ultrasonic wave of frequency f2 is received by the receiver 12 of the following vehicle,
The transmitter/receiver circuit 10 again transmits the ultrasonic wave having the frequency f1 from the transmitter 11 forward. In this way, the ultrasonic waves of frequencies f1 and f2 reciprocate between successive vehicles. This method of repeatedly transmitting and receiving ultrasonic waves between vehicles is called the sing-around method. The reason why ultrasonic waves having different frequencies f1 and f2 are used is to prevent mutual interference.

Ignoring the time delay between receiving and transmitting ultrasonic waves by the transmitting/receiving circuit, the transmission period T of the ultrasonic waves by the transmitting/receiving circuit 10 is equal to the time required for the ultrasonic waves to travel back and forth between successive vehicles. Therefore,
The inter-vehicle distance L from the following vehicle to the preceding vehicle is expressed as L=T/2·W using the wave transmission period T. Here, W is the speed of sound. CPU1
7 uses the transmitted and received signals from the transmitting/receiving circuit 10 to calculate the inter-vehicle distance to the preceding vehicle, as will be shown later. Similarly, the inter-vehicle distance to the following vehicle can also be calculated using the transmitted and received signals from the transmitting/receiving circuit 13.

The transmitter 11 may not transmit the ultrasonic waves immediately after the receiver 12 receives the ultrasonic waves, but the transmitter/receiver circuit 10 may transmit the ultrasonic waves at regular intervals. Alternatively, the transmitted ultrasonic waves from the transmitter 11 may be reflected by the rear surface of the preceding vehicle, and the reflected waves may be received by the receiver 12. However, in the sing-around method, the transmission period of ultrasonic waves changes depending on the distance between vehicles, and as the distance between vehicles becomes smaller, the transmission period becomes shorter.
This is advantageous because more distance information can be obtained.

FIG. 3 shows part of the contents of RAM 18. The RAM 18 includes an area for storing the measured vehicle speed V and inter-vehicle distance L from the preceding vehicle, an area for storing predetermined maximum and minimum allowable distances Lmax and Lmin for constant inter-vehicle distance control, and an area for storing the predetermined allowable maximum and minimum distances Lmax and Lmin for constant speed control. An area for storing a predetermined constant speed parameter VO, and areas used as a leading vehicle flag F1 and a following vehicle flag F2 are provided.

Figure 4 shows ultrasonic wave transmission and reception control by the CPU 17,
The procedure for calculating the inter-vehicle distance L and determining whether the vehicle is the leading vehicle or the following vehicle is shown. First, transmitter 11
(Step 3)
0), CPU 17 calculates the time corresponding to the measurable distance.
(step 31).
Then, it is checked whether the receiver 12 has received the ultrasonic wave of frequency f2 (step 32), and if it has received the ultrasonic wave, it calculates the inter-vehicle distance L to the preceding vehicle according to the above-mentioned principle, and the RAM 18 (Step 35). Since the inter-vehicle distance L is proportional to the time from ultrasonic wave transmission to ultrasonic wave reception, this time may be stored in the RAM 18 as distance L. The fact that the receiver 12 receives the ultrasonic wave with the frequency f2 means that there is a preceding vehicle, so this vehicle is the following vehicle, and the following vehicle flag F2 is turned on (step 36). .

If the ultrasonic wave of frequency f2 is not received even after the preset time preset in the timer has elapsed (NO in step 32, YES in step 33), in principle, if the ultrasonic wave is not received within the measurable distance, Since this means that there is no other vehicle, this vehicle is the leading vehicle, and the leading vehicle flag F1 is turned on (step 34). After the processing in steps 34 and 36, the process returns to step 30 and the ultrasonic wave transmission is repeated.

When the receiver 15 receives an ultrasonic wave of frequency f1 from the following vehicle, this received signal is transmitted to the CPU 1.
7, and the CPU 17 executes the interrupt process. When ultrasonic waves are received (step 3)
7) The ultrasonic wave of frequency f2 is transmitted from the transmitter 14 (step 38), and the interrupt processing is completed.

After transmitting ultrasonic waves from the transmitter 4, by checking whether the receiver 15 has received the ultrasonic waves within a certain period of time (processing similar to steps 30 to 34), the following vehicle can You can determine whether it exists. If there is neither a preceding vehicle nor a following vehicle, this vehicle is traveling alone.

Although illustration of the procedure for measuring the vehicle speed is omitted, the vehicle speed V is determined by counting the time interval of pulses input from the speed detector 23 or the number of pulses input within a certain period of time. V is stored in RAM18. The vehicle speed measurement process is performed at regular intervals.

FIG. 5 shows the procedure of acceleration/deceleration control processing by the CPU 20. First, it is sequentially checked whether the leading vehicle flag F1 is on (step 40) and whether the following vehicle flag F2 is on (step 42). If the flag F1 is on, this vehicle is the leading vehicle, so constant speed control is performed so that it travels at a constant speed represented by the constant speed parameter VO stored in the RAM 18 (step 41). If the leading vehicle is controlled by the center, the constant speed parameter VO is transmitted from the center and stored in the RAM 18. Since the answer at step 40 is YES for a solo vehicle, this constant speed control is performed.

If the flag F2 is on, this vehicle is the following vehicle, so acceleration/deceleration control is performed so that the distance between the vehicle and the preceding vehicle is constant. Read the measured inter-vehicle distance L and the allowable maximum and minimum distances Lmax and Lmin stored in the RAM 18 (step 4).
3), compare these distances. If L>Lmax (YES in step 44), the vehicle is too far away from the preceding vehicle, so an acceleration command is output to the drive circuit 22 to accelerate it (step 45). If L<Lmin (YES in step 46), the vehicle is getting too close to the preceding vehicle, so a deceleration command is output to decelerate the vehicle (step 47). If Lmax≧L≧Lmin (NO in both steps 44 and 46), the vehicle distance is within the allowable range, so the vehicle is allowed to travel at the same speed. In this way, the distance between the following vehicle and the preceding vehicle is maintained within the range of Lmax to Lmin. The process shown in FIG. 5 is repeated at regular intervals. In the acceleration/deceleration control of the following vehicle, if the traveling speed V of the vehicle is taken into consideration and the acceleration/deceleration is performed in multiple stages, more accurate constant inter-vehicle distance control becomes possible.

As described above, the vehicle running control device according to the present invention is applicable to a system in which the operation of a plurality of vehicles is controlled so that they run at a distance from each other in the front and rear without being physically connected. It is installed and used on.

The running control device of this vehicle includes a following distance measuring device that measures the following distance between the preceding vehicle and the preceding vehicle, and a following distance measuring device that measures the following distance between the preceding vehicle and the preceding vehicle. means for detecting the presence or absence of a vehicle and thereby determining whether it is a leading vehicle or a following vehicle; a vehicle speed detector for measuring the traveling speed of the vehicle; The vehicle travels at a predetermined constant speed using the traveling speed measured by the detector, and when it is determined that the vehicle is following, the distance between the vehicle and the preceding vehicle is kept constant using the distance measured by the distance measuring device. The vehicle is equipped with an acceleration/deceleration control device that controls the traveling speed of the vehicle.

All vehicles equipped with the advance control device according to the present invention have a function to determine whether they are the leading vehicle or the following vehicle, and the leading vehicle is subject to constant speed control, and the following vehicle is subject to constant inter-vehicle distance control. It is done. Therefore, when multiple vehicles are operated as a formation, the leading vehicle travels at a constant speed determined in advance, and the following vehicles follow the leading vehicle and reduce the distance between them and the preceding vehicle. Drive at a constant distance between vehicles. Since each vehicle determines its position in the formation order, it is possible to organize the vehicles freely. It is also possible for a single vehicle to travel alone.

[Brief explanation of drawings]

Figure 1 is a diagram showing how multiple vehicles are organized, Figure 2 is a block diagram showing the travel control device of each vehicle, Figure 3 is a diagram showing the contents of RAM, and Figure 4 is a diagram showing the CPU Figure 5 is a flow chart showing the procedure for inter-vehicle distance measurement and vehicle identification processing.
Flowchart showing the acceleration/deceleration control processing procedure by the CPU.
It's a chat. DESCRIPTION OF SYMBOLS 1... Leading vehicle, 2... Following vehicle, 3, 5... Inter-vehicle distance measuring device, 4... Main control device, 11, 14... Ultrasonic wave transmitter, 12, 15... Ultrasonic wave receiver, 10, 1
3... Transmission/reception circuit, 17, 20... CPU, 23... Speed detector.

Claims (1)

[Scope of Claims] 1. A vehicle mounted on each vehicle that is used in a system in which operation is controlled so that a plurality of vehicles run as one train at a distance from each other without being physically connected. It is a driving control device that measures the distance between the preceding vehicle and the preceding vehicle, and includes a following distance measuring device that measures the following distance between the preceding vehicle and the preceding vehicle depending on whether or not the following distance measuring device has obtained the following distance data between the preceding vehicle and the preceding vehicle. means for detecting the presence or absence of a vehicle and thereby determining whether it is a leading vehicle or a following vehicle; a vehicle speed detector for measuring the running speed of the vehicle; and a vehicle speed detection device when the determining means determines that the vehicle is the leading vehicle. When the vehicle is determined to be a following vehicle, the distance between the vehicle and the preceding vehicle is kept constant using the distance measured by the distance measuring device. A vehicle running control device comprising: an acceleration/deceleration control device that controls the running speed of the vehicle. 2 The inter-vehicle distance measurement device transmits ultrasonic waves toward the preceding vehicle, receives the reflected waves from the preceding vehicle, or receives the ultrasonic waves transmitted from the preceding vehicle based on the received ultrasonic waves. The distance between vehicles is measured based on the round trip time of the vehicle, and the determining means determines that the vehicle is the leading vehicle if it does not receive ultrasonic waves from the preceding vehicle for a certain period of time after the ultrasonic wave is transmitted by the distance measuring device. The travel control device according to claim 1.