JPH0533857B2 - - Google Patents

Abstract

PURPOSE:To collect a nearly prescribed number of idle vehicle data by a central management room by controlling the sensitivity of a district receiver from a base station via a wired line. CONSTITUTION:A radio/control display system 4 of a base station generates a sensitivity control signal to switch the sensitivity of a receiver 1-0 of a district from a generator 4-2 as required. The signal is sent to a sensitivity controller 1-1 via a wired line 5-1 tying the district reception system 1 and the base station. The controller 101 decodes the reception signal to switch the sensitivity of the receiver 1-0. Even when the transmission of a vehicle number transmitter 2 of a mobile station is constant, the sensitivity of the receiver 1-0 at the said district is changed, resulting that the arrival effective range of a radio wave is changed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is an AVM (Automatic Application) system that can monitor the operation status of a large number of vehicles such as taxis in a central control room and streamline operation management.
This invention relates to a distributed reception type automotive vehicle position display system that applies a vehicle monitoring (Vehicle Monitoring) method.

[Prior art]

In the conventional automatic vehicle position display system of this kind, the regional receivers are distributed at key points within the driving range of the vehicle, and the vehicle (mobile station) transmits signals indicating the own vehicle's vehicle signal, etc. Repeatedly transmits with low power,
When the vehicle approaches the local receiver, signals such as the vehicle number are received by the local receiver. This received signal is decoded and transmitted from the district receiver to the base station via a wired circuit. The base station processes the data and displays the vehicle's location, number, etc., and also provides necessary instructions and communications to the vehicle via a communication radio system.

[Problem that the invention seeks to solve]

In such a conventional system, the transmitter output of the vehicle number etc. signal is constant, and the sensitivity of the district receiver is also constant, so the effective range of the district receiver is also constant. This is not appropriate for certain tasks. For example, in taxi business,
The number and distribution of empty cars vary greatly depending on the time of day. That is, during busy periods, there are few empty cars and they are scattered widely. During off-peak hours, there are many empty cars, and they tend to be concentrated in several specific areas. For this reason, during busy times there is a high probability that there will be no empty cars within the effective range of the local receiver, and during off-peak times there will be many empty cars within the effective range of the local receiver. Therefore, an object of the present invention is to variably move the effective reception range of the district receiver to display a distributed reception type vehicle position display that can place more empty cars in the area during busy times and fewer empty cars during quiet times. The goal is to provide a system.

[Means for solving problems]

The distributed reception type automatic vehicle position display system according to the present invention includes a plurality of district receivers arranged in a distributed manner, and a mobile station vehicle that is close to any of these district receivers and transmits an identification signal of its own vehicle. In a communication system comprising a wireless device and a base station wireless device that communicates with the vehicle wireless device when the district receiver receives information received from the vehicle wireless device via a wired circuit, the base station wireless device communicates with the vehicle wireless device. A sensitivity control signal generator is provided on the station wireless device side, and a sensitivity controller is provided on the district receiver side, and when the sensitivity controller receives the sensitivity control device from the sensitivity control signal generator via a wired circuit, The sensitivity controller is characterized in that it decodes the received sensitivity control signal to control the reception sensitivity of the district receiver.

[Embodiments of the invention]

Next, an embodiment of the automobile position display system according to the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the structure of an embodiment according to the present invention. In this figure, 1 is a district reception system, 2 is a transmitter of signals such as vehicle number installed on the vehicle, 3 is a radio system for communicating with the base station installed in the vehicle, and 4 is a radio/control display system of the base station. , 5 is a wired circuit between the district receiving system 1 and the base station 4. Furthermore, 1-0 is a receiver, 1-1 is a sensitivity controller for a district receiver, 3-0 is a radio transmitter for communication, 3-1 is a radio transmitter for communication, and 4-0 is a radio transmitter for communication. , 4
-1 is a communication radio receiver, 4-2 is a sensitivity control signal generator, and 4-3 is a data signal processing/display device.

To explain the operation of the system configured in this way, first, the radio/control display system 4 of the base station
, the sensitivity control signal generator 4 is used as necessary.
-2 to the sensitivity of the local receiver 1-0. This signal may be of several types, and may be in tone or digital form, and is transmitted to the sensitivity controller 1-1 via a wired circuit 5-1 connecting the district receiving system 1 and the base station 4.
The sensitivity controller 1-1 of the local reception system receives and decodes this signal, and controls the sensitivity of the receiver 1-0 to be changed.

As a result, even if the transmission output of the vehicle number transmitter 2 of the mobile station is constant, the receiver 1-
The receiving sensitivity of 0 changes, and as a result, the effective reach range of radio waves changes. FIG. 2 shows the characteristics of the required electric field strength at the receiving point versus the effective distance range, which can be changed by controlling the receiving sensitivity in this manner. In other words, if the sensitivity of the district receiver 1-0 is high, the effective range will be wide, so the number of vehicles that can fit there will increase, and if the reception sensitivity is low, the effective range will be narrow.
The number of vehicles that can fit inside is subject to restrictions.

In addition, in the above embodiment, the sensitivity controller 1-
1 may be a mechanically movable part as long as it can be controlled electronically, and the amount of change may be continuous or stepwise. Also, in Figure 1,
Common functional circuits that apply to current receive distributed AVMs are only shown in outline. In particular, the audio part of the communication radio system is omitted because it is not directly related to the features of the present invention.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, by controlling the reception sensitivity of the receiver in the area from the base station via the wired circuit, the arrival of radio waves sent from the mobile station transmitter is improved. Since the range can be adjusted as necessary, it can be applied to taxi services, for example, to avoid situations where there are too many or too few empty cars depending on the time of day, and to centralize data on an almost constant number of empty cars. The benefits of being able to collect information in the control room are significant.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a graph showing the characteristics of received electric field strength versus reachable range in a district receiver. In the figure, 1 is a district reception system, 2 is a vehicle number transmitter, 3 is a communication radio system, 4 is a base station radio/control display system, 1-0 is a receiver, 1-1 is a sensitivity controller, 3 -0 is a communication radio receiver, 3-1 is a communication radio transmitter, 4-0 is a communication radio transmitter, 4-1
is a communication radio receiver, 4-2 is a sensitivity control signal generator, 4-3 is a data signal processing/display device, 5-1,
5-2 is a wired circuit.

Claims (1)

[Claims] 1. A plurality of district receivers arranged in a dispersed manner, a mobile station vehicle radio device that is close to one of these district receivers and transmits an identification signal of the own vehicle, and the district receiver is connected to the vehicle radio In a communication system comprising a base station wireless device that communicates with the vehicle wireless device when information received from the device is received via a wired line, a sensitivity control signal generator is provided on the base station wireless device side. , and a sensitivity controller is provided on the district receiver side, and when the sensitivity controller receives a sensitivity control signal from the sensitivity control signal generator via a wired line, the sensitivity controller transmits the received sensitivity control signal. 1. A reception distributed type automobile position display system, characterized in that the reception sensitivity of the district receiver is controlled by decoding the information.