JPS6233639B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides communication between a vehicle and the ground, measures the travel time of the vehicle in a predetermined section, and based on this measurement result, The present invention relates to a system for detecting the traveling speed of a vehicle, and can be applied to a traffic control system.

[Conventional technology]

Generally, means for externally detecting vehicle speed include ultrasonic or loop type vehicle detectors, which generate pulses with a duration inversely proportional to the vehicle speed, but pulses may vary depending on the shape and length of the vehicle. Since the width changes, it becomes a source of error, making it difficult to obtain accurate vehicle speed.

[Problem that the invention seeks to solve]

The main object of the present invention is to enable accurate speed data to be detected without the above-mentioned error factors.

[Means for solving problems]

Therefore _, in the present invention, in order to achieve the above object, as shown in _FIG . First thing to do
A roadside communication device R ₁ is installed at a second communication point P ₂ located a predetermined distance d from this first roadside communication device R ₁ , and transmits a second communication signal to the vehicle, and transmits a second communication signal to the vehicle. a second on-road communication device R ₂ that receives measurement data transmitted from a vehicle; and a second road communication device R 2 that is mounted on the vehicle C ₁ and runs from receiving the first communication signal to receiving the second communication signal. a measuring device 1 that measures time and transmits the measurement result as travel time measurement data to the _second on-road communication device; The traveling time measurement data received by the roadside communication device R ₂ and the first communication point P ₁
and a vehicle speed calculation device that calculates the traveling speed of the vehicle based on the distance d between the vehicle and the second communication point _P2 .

[Effect]

Therefore, when the vehicle C ₁ passes the first communication point, the first road communication device R ₁ outputs the first communication signal, and the measuring device 1 mounted on the vehicle C ₁ outputs the first communication signal. 1 communication signal is received and time measurement is started. When the vehicle V travels a distance d and reaches the second communication point, a second communication signal is transmitted from the second road communication device _R2 , and the measuring device 1 receives this second communication signal. The second on-road communication device uses the time measured up to that point as travel time measurement data.
Send to _R2 . This traveling time measurement data is transmitted from the second road communication device _R2 to the vehicle speed calculation device _E2 . The vehicle speed calculating device _E2 calculates the traveling speed of the vehicle _C1 from the traveling time measurement data and the pre-stored distance d between the first communication point _P1 and the second communication point _P2 .

As described above, according to the present invention, the measuring device 1 mounted on the vehicle starts measuring time when the vehicle _C1 reaches the first communication point, and starts measuring the time when the vehicle C1 reaches the second communication point. Since the measurement is stopped, the measured value of the time required to travel the predetermined distance d is
It is not affected by the size or type of C ₁ .

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, an antenna _{L 1 of a first communication device R 1 is} installed in the road space of a first communication point P 1 near an intersection I ₁ , and is located at a predetermined distance d from the point P ₁ .
An antenna L ₂ of a second communication device R ₂ is installed in the road space of a second communication point P 2 near the intersection I ₂ , which is located a distance away from the intersection I ₂ . The communication devices R ₁ and R ₂ are equipped with data conversion devices E ₁ and E ₂ that calculate the vehicle speed based on the data received from the antennas L ₁ and L ₂ and convert the calculation results into pulses with a time width indicative of the calculation result. It is connected. Furthermore, the data conversion devices E ₁ and E ₂ are connected to the traffic lights S ₁ and S 2 respectively, and the data conversion devices E 1 and E ₂ are connected to the traffic lights S ₁ and S ₂ respectively.
is connected to the air traffic control device A via signal transmission lines D ₁ and D ₂ . Therefore, pulses indicating vehicle speed data are sent to the air traffic control device A via the transmission lines _D1 and _D2 .
Based on this vehicle speed data, traffic control device A can perform traffic control of traffic signals S ₁ and S ₂ .

FIG. 2 shows the detailed configuration of the running time measuring device 1 mounted on the vehicle C ₁ , and the symbol 1 is a communication device.
An antenna for transmitting and receiving data to and from R ₁ and R ₂ is shown, and a signal received by antenna l is input to receiving circuit 1A. The receiving circuit 1A outputs a timing signal T1 when receiving the first communication signal from the communication device _R1 , and outputs _a timing signal _T2 when receiving the second communication signal from the communication device _R2 . It is configured. The time measurement circuit 1T is a digital clock 1B that outputs clock pulses of a constant frequency.
a counter 1C that counts the clock pulses 1B from when the timing signal _T1 is input until the timing signal _T2 is input; and an encoding circuit 1D that encodes the value counted by the counter 1C. It consists of The data encoded by the encoding circuit 1D is
The signal is transmitted via an antenna in the transmitting circuit 1E.

Next, the operation of this embodiment having the above configuration will be explained. In FIG. 1, it is assumed that the vehicle _C1 is moving in the direction of the arrow. When the vehicle C ₁ now arrives at the first communication point P ₁ , the vehicle's communication device (transmission circuit, reception circuit) and the communication device R ₁ on the road communicate with each other via the antennas L and L ₁ in a known manner. . At this time, the receiving circuit on the vehicle side generates a timing signal _T1 and applies it to the counter 1C according to a command from the roadside communication device _R1 . From this point on, the counter 1C starts counting by receiving clock pulses of a constant frequency from the on-board digital clock.

When the vehicle continues to travel and reaches the second communication point _P2 , the vehicle's communication device enters into communication with the communication device _R2 on the road. At this time, the receiving circuit on the vehicle side generates a timing signal _T2 according to a command from the roadside communication device _R2 , and the counter 1 is activated by this timing signal.
At the same time as stopping the function of C, the encoding circuit 1D is activated to obtain the count value CT, that is, from point P _1.
The travel time information up to P ₂ is encoded, for example a serial binary signal. This encoded information is sent to the roadside communication device R ₂ via the transmission circuit and antennas 1 and L ₂ .

The road communication device R ₂ extracts encoded information indicating the counter value from the data received from the vehicle C ₁ and transmits it to the data conversion device E. In the data conversion device E, since the distance d between points P ₁ and P ₂ is known in advance, the average vehicle speed V ₁₂ of the vehicle C ₁ is
It is obtained by digital calculation of V ₁₂ = d ₁₂ /CT (where CT is a count value). Furthermore, this calculation result is converted into time length data by a known binary number-to-time length conversion circuit, and the time width T ₁₂ =K・V ₁₂ (K
is a proportional coefficient) and is output as a pulse signal.

This pulse signal is transmitted to the higher-level traffic control device A via the traffic signal S ₂ and the signal transmission path D ₂ . Incidentally, a system is known in which detection data of a vehicle sensor is sampled at regular intervals using a traffic signal and transmitted to a higher-level control device, as described in the conventional example.

In this way, the traffic control device A can receive the vehicle speed data actually measured by the vehicle _C1 and perform predetermined traffic control.

Note that the number and location of communication points can be arbitrarily selected, and can be used to detect traffic conditions between each point. Furthermore, by providing communication points independently for each lane on the road, vehicle speed data for each lane can be obtained. Also, the vehicle
If data indicating the unique emergency vehicle of C ₁ is encoded and simultaneously transmitted from vehicle C ₁ to the roadside equipment, control device A can instruct traffic control so that the emergency vehicle can travel more smoothly. It also becomes possible.

〔Effect of the invention〕

As described above, the present invention encodes travel time vehicle speed data actually measured by a vehicle and transmits it to a road device.
By calculating the vehicle speed based on travel time data in a roadside device, there is an excellent effect that accurate speed data can be detected without errors caused by vehicle shape, vehicle length, etc.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of on-road equipment according to the present invention, FIG. 2 is a configuration diagram of on-vehicle equipment according to the present invention, and FIG. 3 is a block diagram showing the configuration of the present invention. 1...Measuring device, 1T...Time measuring circuit, C ₁
... Vehicle, l, L ₁ , L ₂ ... Antenna (antenna),
R ₁ , R ₂ ...Communication equipment forming road equipment, E ₁ , E ₂ ...Data conversion device (vehicle speed calculation device).

Claims (1)

[Claims] 1. A first road communication device R ₁ installed at a first communication point P ₁ on the road and outputting a first communication signal to a running vehicle; A second road device installed at a second communication point P ₂ a predetermined distance away from the communication device R ₁ and outputting a second communication signal to the vehicle and receiving measurement data transmitted from the vehicle. communication device
_R2 , which is mounted on the vehicle and measures the running time from receiving the first communication signal to receiving the second communication signal, and uses this measurement result as the running time measurement data to be used as the second communication signal. a measuring device 1 that transmits to a roadside communication device R ₂ ; a measuring device 1 that is connected to the second roadside communication device R ₂ so as to be able to transmit data; and the travel time measurement data that is received by the second roadside communication device R ₂ ; Based on the distance between the first communication point P ₁ and the second communication point P ₂ ,
Vehicle speed calculation device E ₂ that calculates the traveling speed of the vehicle
A vehicle speed measurement system for traffic control, comprising: