JPH0468566B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a travel route display device that displays the current position and travel trajectory of a moving object such as an automobile on a screen on which a map is displayed in advance.

Prior Art Recently, distance detection has been developed as the vehicle travels, in order to provide appropriate guidance so that the driver does not deviate from the planned course and get lost when driving a vehicle, for example, in an unfamiliar area. The distance traveled according to the vehicle speed is detected by the device, and the direction of travel and the amount of change thereof are detected by the direction detector every moment, and the current position of the vehicle, etc. on the two-dimensional coordinates is determined from each detected value by sequential calculation. To display continuous point information that changes every moment on a screen displaying a map of a planned driving area based on map image information read out in advance from a map information storage medium while storing and retaining the result. Accordingly, a driving route display device has been developed that allows the driver to confirm the current location.

Conventionally, in such a driving route display device,
If a geomagnetic sensor is used as a direction detector, the influence of disturbances such as when a moving object passes through a railroad crossing or an overpass is significant, so a gas rate sensor that is free from such disturbances is used. In a gas rate sensor, a gas flow is ejected from a nozzle in a sealed casing toward a pair of temperature-sensing elements as a flow sensor. This device detects the magnitude of angular velocity (rate) from the output difference between a pair of temperature sensing elements, and since changes in ambient temperature act as disturbances and adversely affect detection accuracy, the inside of the casing is forcibly heated using a heater. The internal temperature is monitored by a temperature sensor and temperature control is performed to maintain a constant temperature.

However, in a gas rate sensor that uses a temperature control means using a heater, the power consumption at the start-up time when the heater power is turned on is larger than that in the steady state. If power is applied to the gas rate sensor at the same time as a playback device for map information storage media such as a laser disk that requires motor drive current, the current capacity of the power supply system, including the fuse, must be set large. There is. Furthermore, it takes a relatively long time for the internal temperature to become constant, and the direction detection accuracy decreases during this time.

Purpose The present invention was made in consideration of the above points, and
Even when using a gas rate sensor that takes the above-mentioned temperature control means, the current capacity in the power supply system can be suppressed, and when the main power switch is turned on, accurate direction detection is immediately performed and the driving route display operation is started. The present invention provides a driving route display device that can display a driving route.

Configuration In order to achieve the object, the present invention provides the following steps when starting the travel route display device by turning on the main power switch.
A power supply control means for supplying power to the gas rate sensor after the map information storage medium reproducing device is powered on and power has been turned on, and a main power switch for preventing a delay in the driving route display operation. Backup means is used to detect the direction by the geomagnetic sensor from when the map information storage medium is turned on until the start-up of the map information storage medium reproducing device is completed and further until the start-up of the gas rate sensor is completed.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 shows the basic configuration of the travel route display device according to the present invention, which is composed of a photoelectric type, electromagnetic type, or mechanical contact type sensor that outputs a pulse signal proportional to the number of rotations of a tire. A distance detector 1 that generates a signal according to the distance, a direction detector 2 that outputs a signal proportional to the amount of change in the direction of movement of the moving body according to a change in the direction of travel, and a pulse from the distance detector 1. The moving distance of the moving object is measured by counting the signals, and the traveling direction of the moving object is determined from the output of the direction detector 2. A signal processing device CPU 3 which calculates the position on the two-dimensional coordinates by calculation and centrally controls the entire device; Consisting of a movement trajectory storage device RAM4 that sequentially stores data and holds it as finite continuous position information corresponding to the current position of the moving object, and a laser disk, video tape, etc. that stores image information of multiple maps in advance. A map information storage medium 5, a storage medium playback device 6 that reads out necessary map image information from the storage medium 5, displays a map image on a screen according to the read out image information, and displays the movement trajectory memory. Based on the position data stored in the device 4, a display command is given to the signal processing device 3 and a display device 7 that displays the current position of the moving body, its travel trajectory so far, the current direction of travel, etc. on the same screen in an updated manner every moment. At the same time, it is possible to select and designate the map to be displayed on the display device 7, change the direction of the displayed map and the driving trajectory, shift the display position, display enlarged portions of the map and the driving trajectory, select the display scale, etc. The vehicle is comprised of an operating device 8 that can be used to change settings, search for maps and travel trajectories, etc. as appropriate.

With this configuration, a map of the planned travel area that is accessed and read out from the map information storage medium is displayed on the screen of the display device 7, and a signal is displayed as the mobile object travels. The processing device 3 calculates the current position x, y on the X-Y coordinates every moment according to the map scale rate set in advance, and the results of the calculation are sequentially sent to the display device 7 and the movement trajectory. The data is sent to the storage device 4 and stored therein, and the stored contents are constantly read out and continuously sent to the display device 7, and the display device 7 displays the following information as shown in FIG.
On the travel schedule map displayed on the screen, there is a display mark M1 indicating the current position of the moving body, a display mark M2 indicating the traveling direction of the moving body at the current position, and a display mark indicating the traveling trajectory from the starting point to the current position. M3 is displayed in a simulated manner following the moving state of the moving body.

In such a traveling route display device, particularly in the present invention, a gas rate sensor with temperature control is used as the direction detector 2.

FIG. 5 shows an example of the configuration of this type of gas rate sensor.

In the configuration shown in the figure, gas trapped in the casing 10 is compressed in the pump chamber 11 in which the piezo plate 12 is provided, and the compressed gas is discharged from the discharge port 13 to the outer flow path 14 and from the nozzle hole 16. The inner flow path 2 of the sensor main body 15 is rectified.
2 and is ejected toward a pair of temperature sensing elements 17 and 18. However, when an angular velocity motion is applied to such a gas rate sensor from the outside, the gas flow in the inner flow path 22 is deflected depending on the magnitude of the motion, and a difference in output occurs between the pair of temperature sensing elements 17 and 18 at that time. , a detection signal based on a minute change in the output difference is amplified by the amplifier circuit 19 and taken out to the outside.

A heater wire 20 is spirally wound around the outside of the casing 10.
A temperature sensor 21 is provided inside the casing 10, and the temperature inside the casing 10 is kept constant at all times by controlling the supply of electricity to the heater wire 20 while being monitored by the temperature sensor 21. Specifically, the signal processing device 3 in the travel route display device reads the output of the temperature sensor 21 and controls the energization of the heater wire 20 so that the detected temperature is constant.

Therefore, in the present invention, first of all, when starting the travel route display device, power is supplied to the gas rate sensor after the map information storage medium reproducing device 6 having the motor drive unit is powered on and the power supply is completed. I am trying to take control measures.

FIG. 1 shows a specific circuit configuration for controlling the power supply.

Here, we will turn on the main power switch of the driving route display device.
The timer T is set in advance in anticipation of the time from when the battery power supply B is turned on to the storage medium playback device 6 when the switch is turned on until the start-up is completed. After the elapsed time, relay RY is energized and its relay contacts
By closing RY-a, battery power source B is turned on to direction detector 2, which is a gas rate sensor with temperature control.

FIG. 2 shows the current characteristics of the storage medium reproducing device 6 and the direction detector 2 consisting of the gas rate sensor at the time of startup. In the figure, t ₀ is the time when the main power switch SW is turned on, t ₁ is the time when the storage medium playback device 6 completes startup, t ₂ is the time when the direction detector 2 consisting of a gas rate sensor with temperature control completes startup, and Tw is the time when the startup is completed. Each shows the set time of timer T.

Therefore, by adopting such a power supply control means, it is possible to reduce the load on the battery power supply B when the main power switch SW of the travel route display device is turned on, and effectively suppress its power consumption. It becomes possible to set the current capacity in the power supply system to a small value including the current capacity.

As another specific means for power supply control, the signal processing device 3 detects the completion of start-up of the map information storage medium reproducing device 6 by monitoring the motor speed or motor drive current, and uses the detection signal as a signal. Accordingly, the direction detector 2, which is a gas rate sensor with temperature control, may be powered on.

Note that when the engine of the mobile object is stopped while the power supply control is being executed, the signal processing device 3 detects the engine stop state and stops the power supply control.

In addition, in the present invention, secondly, as shown in FIG. 1, a geomagnetic sensor 9 is additionally provided, and the start-up of the direction detector 2 consisting of a gas rate sensor with a temperature sensor under the aforementioned power supply control is completed. Until then, that is, the period from t ₁ to t ₂ in Figure 2,
Backup means is used to detect the direction using the geomagnetic sensor 9.

However, if such direction detection backup means is adopted, it is possible to eliminate the need to use the direction detector 2, whose detection accuracy is unstable until the temperature inside the gas rate sensor rises to a constant level. During this time, the direction is detected by the geomagnetic sensor 9, so that the driving route can be immediately displayed with high precision.
Note that for backup, it is necessary to start up the storage medium playback device 6 preferentially.

Effects As described above, in the traveling route display device according to the present invention, when a gas rate sensor with a temperature control that maintains the internal temperature constant by forced heating is used as a direction detector, the above-mentioned power supply control means and Since the geomagnetic sensor is also used as a backup means for direction detection, the current capacity of the power supply system can be effectively suppressed, and accurate direction detection can be performed immediately when the main power switch is turned on. This has the excellent advantage of being able to start the driving route display operation.

[Brief explanation of the drawing]

Fig. 1 is an electric circuit diagram showing an example of the configuration of a power supply control circuit, Fig. 2 is a waveform diagram showing current characteristics at startup of the storage medium playback device and direction detector, and Fig. 3 is a waveform diagram of the driving route display device. FIG. 4 is a block diagram showing an example of display contents on the screen of the travel route display device, and FIG. 5 is a front sectional view showing an example of the configuration of a gas rate sensor with temperature control. 1... Distance detector, 2... Direction detector, 3...
Signal processing device, 4... Movement trajectory storage device, 5...
Map information storage medium, 6...Storage medium playback device, 7
...Display device, 8...Operation device, 9...Geomagnetic sensor, T...Timer, RY...Relay.

Claims (1)

[Claims] 1 Based on the detection outputs of the distance detector that detects the traveling distance of the moving object and the direction detector that detects the traveling direction, the signal processing device calculates the position on the two-dimensional coordinates for each unit of traveling distance of the moving object. , and a driving route display device that updates and displays the current position of a moving object on a map displayed on the screen of a display device from a map information storage medium in which map image information is stored in advance through the storage medium playback device. In,
A gas rate sensor with a temperature control that maintains the internal temperature constant by forced heating by a heater is used as the direction detector, and when the driving route display device is started by turning on the main power switch, the storage medium reproducing device A power supply control means is provided to supply power to the gas rate sensor after the start-up is completed by turning on the power, and after the main power switch is turned on, the start-up of the storage medium reproducing device is completed and further the start-up of the gas rate sensor is completed. 1. A travel route display device characterized in that a backup means is used to detect a direction using a geomagnetic sensor.