GB2066953A

GB2066953A - Route indicating apparatus

Info

Publication number: GB2066953A
Application number: GB8037597A
Authority: GB
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 1979-11-28
Filing date: 1980-11-24
Publication date: 1981-07-15
Also published as: JPS5677882A; GB2066953B; FR2470954B1; FR2470954A1; JPS5824794B2

Abstract

Apparatus for use in a vehicle comprises means (1) for periodically detecting the distance travelled by a vehicle, means (2) for detecting the bearing taken by a vehicle, a signal processor (3) for arithmetically obtaining a current location of the vehicle in terms of two-dimensional coordinates at intervals, using signals from the means (1, 2), means (4) for storing data regarding such locations, means (5) for displaying the path of travel of the vehicle in accordance with the data stored, and operating means (6) for controlling the display. The means (3), (4), (5) are located in a housing with a display screen of the display (5) arranged at a front surface of the housing. Map holding means are arranged on the housing for releasably holding a map in front of the display screen. <IMAGE>

Description

SPECIFICATION Travel route indication apparatus The present invention relates to travel route indication apparatus.

In an attempt to prevent the driver of a vehicle or the like from losing his way when driving, on such an occasion as at night or in a strange piace, away from his desired route of travel, there has been developed a variety of apparatus for indicating continuously or discretely a current vehicle position or like information by means of an indicator panel or display screen, including a related road map or the like, disposed at the driver's seat so that he may receive suitable guidance relating to the vehicle's current position with respect to a desired course of travel.

In the conventional travel route indication apparatus for such an application, the current running distance of a vehicle is detected in accordance with its running speed and time by a distance detecting section, and a current bearing and thus azimuthal deviation of the vehicle are detected by a bearing detecting section empioying, for example, a rate gyroscope or the like adapted to detect a possible angular velocity produced about the axis of yawing of the vehicle. The current location of the vehicle along its travel route is thus obtained by an arithmetic operation using this detected data, and the results are indicated by way of spot information varying from time to time on a display which also indicates a suitable road map of routes or roads on which the vehicle runs.

With the conventional arrangement described above, however, it is very possible that spot information showing a current location of the vehicle on the display would deviate from a predetermined course of travel owing to an accumulated error in detection (as created from a possible drift of the gyroscope) while the vehicle is running, to such an extent that such information would indicate an erroneous location of the vehicle on the display screen including a map of complicated and crowded roads and streets.

Therefore, it is practically very difficult or even impossible for the vehicle's driver to determine whether the displayed information on the screen is erroneous or his vehicle is actually running in a different or wrong way, thus making it ambiguous.

According to the present invention there is provided travel route indication apparatus for use in a vehicle, which apparatus comprises, in combination: first detection means adapted to detect in use a current distance travelled by such a vehicle; second detection means adapted to detect a current bearing taken by such a vehicle; signal processing means adapted to arithmetically obtain a current location of the vehicle, in terms of two-dimensional coordinates, at intervals of a given unit running distance of such a vehicle on the basis of signals from the first and second detection means; path of travel storage means adapted to store data regarding such locations obtained at intervals from the signal processing means; display means adapted to display the path of travel of such a vehicle in accordance with such data stored in the storage means; operating means for controlling the display of the path of travel by the display means; a housing for the signal processing means, the path of travel storage means, and the display means, a display screen of the display means being disposed at the front surface of the housing and map holding means disposed on the housing for releasably holding a map in front of the display screen.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 7 shows a schematic block diagram of circuitry of a vehicle travel route indicating apparatus; Figure 2 shows a schematic view of a typical visual indication on a display unit of the apparatus shown in Figure 1; Figure 3 shows a plan view from above of the apparatus of Figure 1; Figure 4 shows a front elevational view of the apparatus of Figure 1; Figure 5 shows a vertical cross-sectional view through the apparatus shown in Figures 3 and 4; and Figure 6 shows a side elevational view of the apparatus shown in Figures 3 and 4 with a douser hood thereof in its retracted position.

Referring to Figure 1, the travel route indicating apparatus shown comprises a distance detection unit 1 which is adapted to generate an electrical signal to enable calculation of a current running distance of a vehicle and which includes a sensor and pulse generator of the photoelectric, electromagnetic or mechanical contact type for generating electrical pulses proportional to, for example, the number of revolutions of the vehicle's wheels. The apparatus further comprises a bearing detection unit 2 for providing an electrical signal proportional to a current bearing, or a current amount of azimuthal deviation, of the vehicle corresponding to a current running direction thereof with respect to a predetermined reference and which includes, for instance, a rate gyroscope adapted to detect an angular velocity in the yawing plane.A signal processing unit or central processing unit (CPU) 3 is adapted to count the electrical pulses from the distance detection unit 1 so as to measure the current running distance of the vehicle, and is also adapted to determine the current running direction of the vehicle from the output signal of the bearing detection unit 2 and to arithmetically obtain a current position in twodimensional coordinates at intervals of a unit running distance of the vehicle, while centrally controlling the entire apparatus. A path of travel storage unit or random access memory (RAM) 4 is adapted to sequentially store data concerning distance positions or spots in the two-dimensional coordinates which vary from time to time and which are obtained by the signal processing unit 3, and to hold the data as finite and continuous information regarding the current location of the vehicle.A display unit 5 including a CRT display, a liquid crystal display, etc.

is adapted to visually indicate such information, as updated from time to time, as the current running distance of the vehicle, a path of travel from a given zone to the current location, and the current vehicle running direction and the time required, in accordance with the output from the signal processing unit 3. A manual operating unit 6 is adapted to appropriately modify settings such as a directional change of the path of travel of the vehicle as visually indicated on the display unit 5, a shift of the position of such an indication, a partially enlarged indication of the path of travel, a manual selection of a scale of indication, etc.

In operation of the apparatus, firstly, a predetermined starting or reference point of the vehicle and a desired scale of indication are manually preset on the display unit 5, in accordance with a road map displayed thereon, by the manual operating unit 6.

After such setting, and when the vehicle starts running, a single electrical pulse signal is sent at intervals of a unit running distance from the distance detection unit 1 to the signal processing unit 3, wherein the number of pulses is counted so as to measure a current running distance of the vehicle.

The output of the bearing detection unit 2 is also supplied to the signal processing unit 3 so as to determine a cruising direction or azimuth of the vehicle at each instant. The signal processing unit 3, as stated above, operates to arithmetically obtain from time to time a current location or graphic point (x, y) on the X-Y coordinates in the preselected scale of indication on the display unit 5 in accordance with the current running distance and the current azimuthal deviation of the vehicle. The results of the arithmetical operation are sequentially sent to the display unit 5, and also to the path of travel storage unit (RAM) 4 for storage therein. The stored content of the RAM 4 is constantly read-out and supplied to the display unit 5 continually.At the same time, an azimuthal signal at the current location of the vehicle is sequentially supplied from the signal processing unit 3 to the display unit 5.

More specifically, as typically shown in Figure 2, these inputs to the display unit 5 from both the path of travel storage unit 4 and the signal processing unit 3 are adapted to visually indicate, on the display unit 5, by means of an azimuthal indication mark M1 appearing at the current location B of the vehicle and a path of travel indication mark M2 showing the path of travel from the predetermined starting or reference point A to the current location B of the vehicle in a simulated manner to foilow the travel route of the vehicle.In this connection, for the purpose of verifying whether or not the path of travel of the vehicle up to a current point complies with a desired path, it is arranged that a retrieval mark M3 may be placed anywhere along the path of travel indication mark M2 indicated on the display unit 5 by a manual operation of the manual operating unit 6.

The display unit 5 is also arranged, as shown in Figure 2, so that there may be indicated such additional auxiliary information, in accordance with signals supplied from the signal processing unit 3, as an indication of time D1 required for the vehicle's travel, for instance, from the current location B to a predetermined reference point (which is adaptable by the use of a suitable timer incorporated in the signal processing unit 3 so as to work during the time period that the vehicle runs), an indication of the current total mileage D2 up to that location B, or an indication of the display scale selected by means of the manual operating unit 6, as desired.

As there is a physical or spatial limit to the visual indication of the path of travel of the vehicle on the display 5 (which has a finite display area), then when the path of the vehicle's travel extends beyond the extremity of the display as the vehicle proceeds, it may be arranged that a new starting or reference point A' is set on a cleared or refreshed indication on the display unit 5 by the manual operating unit 6, thus providing another scroll of indication. This procedure may be repeated as often as desired. In this connection, it is feasible to arrange for a limit frame (not shown) to be shown for a single scroll of indication on the display such that when the current location B of the vehicle reaches that limit frame on the display, a warding to that effect is immediately given to the vehicle's driver.More specifically, there are preset maximum values in both the X and Y axes of coordinates corresponding to the frame area of such a limit frame in the signal processing unit 3, thus enabling an alarm to function when a warning input is produced upon the current location point (x, y) of the vehicle reaching either of these maximum values. Also, it is of course possible for the driver to provide the signal processing unit 3 with a command by means of the manual operating unit 6 when so desired, whereupon the contents of the path of travel storage unit 4 are read-out for indication on the display unit 5 instead of the constant indication of the path of travel on the display unit 5 as described above.

It is thus possible for the vehicle's driver to readily and assuredly identify in which way his vehicle is cruising by means of reference of a current path of travel as visually indicated upon the screen of the display unit 5 to the pattern of a road on the map shown on the display screen. Even if there has been an accumulated error from a relatively long travel of the vehicle till the moment of inspection by the driver, when a part of the path of travel is specifically compared to a corresponding pattern of a road followed by the vehicle where there is particularly a specific feature - such as the last curve as shown in Figure 2then only an accumulated error after that particular pattern of road will be noted, thus enabling the vehicle's driver to determine his location at that moment with an easy approximation.

In addition, by virtue of advantages such that the path of travel of the vehicle is held continuously in the visual indication for a given extension or zone that has been travelled by the vehicle, it is possible for the vehicle's driver to grasp a general idea of deviation of the actual travel of his vehicle, if any, in terms of either distance or orientation away from the desired or predetermined path of travel.Also, it is practicable for him to determine a current location of the vehicle more efficiently and assuredly by means of changing the scale of indication of the path of travel on the display screen, lustifying the thus- obtained indication upon the due course of travel on the map indicated on the display, rotating selectively the orientation of the indication on the display to suit to the current direction of cruising, or enlarging particular points passed by the vehicle, as desired.

Referring now to Figures 3 to 5, there is shown an outer housing or cabinet 7 for the apparatus, in which there are assembled, as a unit, the signal processing unit 3, the path of travel storage unit 4, the display unit 5 and the manual operating unit 6 (ail of which are not shown in these figures). In addition, a cathode ray tube (CRT) 8 is arranged in the housing 7 with its screen facing the front thereof, a map holder plate 9 being disposed in the front of the CRT screen for supporting, in position, a sheet of road map for specific use with this apparatus in such a manner that the road map may be selectively displaced along the screen face in any direction according to the passage of the vehicle.A light table 10 (i.e. a back-lit area) is disposed in the front of the housing 7 and has an area as large as the overall front elevational side of the housing 7 except for the screen of the CRT 8 located therein. A lamp house 11 is included in the interior of the housing 7 and is adapted to illuminate the lighttable 10. An operating switch panel 12 is disposed in the front lower part of the housing 7, and a douser hood 13 is slidably engaged with a rail 16 located on the top of the housing 7 and consisting of a top plate 131 and side plates 132 depending downwardly therefrom with a wider space therebetween than the overall width of the housing 7. A map receiving pocket 14 is integrally formed in the upper plate 131 of the douser hood 13, and a tab 15 projects outwardly from the front end of the upper plate 131 for manual handling of the douser hood 13.Though not shown in the drawing, there are arranged a control drive circuit for the CRT 8, the signal processing unit 3 and the path of travel storage unit 4 in a space 17 inside the housing 7. Also, in the operating switch panel 12, there is provided an upper cover 121 adapted to assist a bright projection of the sheet of road map, in which upper cover 121 there are included a main supply switch SW1, a switch SW2 for the lamp house 11, and a group of switches SW3 for the manual operating unit 6.Among the group of switches SW3 switches for such desired controi as the adjustment of the gyroscope for the bearing detection unit 2, the seting of the timer, the setting of a predetermined starting point in the display unit 5, and the selection of a desired scale of indication on the display unit 5 may be arranged for easy operation by the vehicle's driver at his seat during driving.Also, switches for adjustments that are required for the recognition of a current location of the vehicle by reference to the road map set against the screen of the CRT 8, such as the shifting of the visual indication on the display unit 5, the rotation or enlargement (for example, magnification of the order of 2n) of such indication, etc. and/or switches for the setting of visual marks along the current path of travel may be enclosed in an independent, handy case disposed for ready operation by the driver.

The apparatus functions in the following manner.

First, a sheet of road map prepared for specific use with the apparatus is held in position in front of the display screen of the CRT 8 by using the map holder plate 9. A desired scale of indication on the display screen in accordance with a given scale of the map and a starting or reference point of the vehicle motion in accordance with a desired course of travel on the map may then beset appropriately, prior to starting, by using the switches of the switch panel 12. After such preliminary procedures, the vehicle is started and subsequently there is visually indicated an actual path of travel of the vehicle as the driver drives his vehicle in accordance with the road map on display. Accordingly, it is feasible for the vehicle's driver to constantly determine a current location of the vehicle efficiently and assuredly while referring to the map on display.However farthe vehicle may deviate, away from a predetermined course of travel on the map, on the display screen because of an accumulated error in the positional detection as the vehicle runs, it is easy to correct such an occasional deviation by manual adjustment of the displayed position by using an operating switch or by the manual shifting of the map resiliently held by the - holder plate 9. By virtue of the douser hood 13, which may be adjusted by sliding such that it extends over the display screen of the CRT 8, any external lights from above or either side may effectively be blocked-out so that details displayed on the CRT 8 may be viewed clearly, while allowing the map held by the holder plate 9 to be moved for .

adjustment as desired. When the douser hood 13 is not in use, it may be slidably retracted to its storage position above the housing 7 as shown in Figure 6, thus effecting a saving of space therearound within the limited confinement of the vehicle's interior.

Also, by illuminating the light table 10 as desired, the map may be viewed brightly and easily. This is particularly advantageous for driving in darkness.

With such a construction it is possible in practice to house all of the components of the apparatus compactly within its housing 7 in such a manner that the driver of a vehicle can constantly determine the current status of travelling of his vehicle efficiently and confidently while referring to the suitable sheet of road map.

Claims

1. Travel route indication apparatus for use in a vehicle, which apparatus comprises, in combination: first detection means adapted to detect in use a current distance travelled by such a vehicle; second detection means adapted to detect a current bearing taken by such a vehicle; signal processing means adapted to arithmetically obtain a current location of the vehicle, in terms of two-dimensional coordinates, at intervals of a given unit running distance of such a vehicle on the basis of signals from the first and second detection means; path of travel storage means adapted to store data regarding such locations obtained at intervals from the signal processing means; display means adapted to display the path of travel of such a vehicle in accordance with such data stored in the storage means; operating means for controlling the display of the path of travel by the display means; a housing for the signal processing means, the path of travel storage means, and the display means, a display screen of the display means being disposed at a front surface of the housing; and map holding means disposed on the housing for releasably holding a map in front of the display screen.

2. Travel route indication apparatus according to claim 1, further comprising a douser hood which is slidably engaged with rail means disposed at an upper surface of the housing.

3. Travel route indication apparatus according to claim 2, further comprising a recessed pocket integrally formed on an upper surface of the douser hood and adapted to receive such a map.

4. Travel route indication apparatus according to any preceding claim, wherein the front surface of the housing is provided with a back-lit area for illuminating such a map.

5. Travel route indication apparatus according to any preceding claim, wherein the operating means is attached to the housing.

6. Travel route indication apparatus substantially as herein described with reference to the accompanying drawings.

7. Avehicle provided with travel route indication apparatus according to any preceding claim.