Milestone-Proposal:Honda Electro Gyrocator: The World's First Map-based Automotive Navigation System, 1981


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Docket #:2014-10

This Proposal has been approved, and is now a Milestone


To the proposer’s knowledge, is this achievement subject to litigation? No

Is the achievement you are proposing more than 25 years old? Yes

Is the achievement you are proposing within IEEE’s fields of interest? (e.g. “the theory and practice of electrical, electronics, communications and computer engineering, as well as computer science, the allied branches of engineering and the related arts and sciences” – from the IEEE Constitution) Yes

Did the achievement provide a meaningful benefit for humanity? Yes

Was it of at least regional importance? Yes

Has an IEEE Organizational Unit agreed to pay for the milestone plaque(s)? Yes

Has an IEEE Organizational Unit agreed to arrange the dedication ceremony? Yes

Has the IEEE Section in which the milestone is located agreed to take responsibility for the plaque after it is dedicated? Yes

Has the owner of the site agreed to have it designated as an Electrical Engineering Milestone? Yes


Year or range of years in which the achievement occurred:

1981: The year 1981 is the one when the world’s first navigation system ‘Honda Electro Gyrocator’ was released.

Title of the proposed milestone:

Map-Based Automotive Navigation System, 1981

Plaque citation summarizing the achievement and its significance:

The world’s first map-based automotive navigation system, ‘Honda Electro Gyrocator’, was released in 1981. This system was based on inertial navigation technology using mileage and gyro sensors. It pioneered the on-board display of the destination path of a moving vehicle on overlaying transparent road-map sheets, and contributed to the advancement of automotive navigation systems.

In what IEEE section(s) does it reside?

IEEE Tokyo Section

IEEE Organizational Unit(s) which have agreed to sponsor the Milestone:

IEEE Organizational Unit(s) paying for milestone plaque(s):

Unit: IEEE Tokyo Section
Senior Officer Name: Senior officer name masked to public

IEEE Organizational Unit(s) arranging the dedication ceremony:

Unit: IEEE Tokyo Section
Senior Officer Name: Senior officer name masked to public

IEEE section(s) monitoring the plaque(s):

IEEE Section: IEEE Tokyo Section
IEEE Section Chair name: Section chair name masked to public

Milestone proposer(s):

Proposer name: Proposer's name masked to public
Proposer email: Proposer's email masked to public

Please note: your email address and contact information will be masked on the website for privacy reasons. Only IEEE History Center Staff will be able to view the email address.

Street address(es) and GPS coordinates of the intended milestone plaque site(s):

Honda Collection Hall

Address: 120-1 Hiyama, Motegi-cho, Haga-gun, Tochigi, 321-3597 Japan

GPS Coordinates: Latitude : 36.526825, Longitude : 140.226713,

Describe briefly the intended site(s) of the milestone plaque(s). The intended site(s) must have a direct connection with the achievement (e.g. where developed, invented, tested, demonstrated, installed, or operated, etc.). A museum where a device or example of the technology is displayed, or the university where the inventor studied, are not, in themselves, sufficient connection for a milestone plaque.

Please give the address(es) of the plaque site(s) (GPS coordinates if you have them). Also please give the details of the mounting, i.e. on the outside of the building, in the ground floor entrance hall, on a plinth on the grounds, etc. If visitors to the plaque site will need to go through security, or make an appointment, please give the contact information visitors will need. Honda Collection Hall, which is exhibiting all of Honda’s historical products and award certificates/plaques, including the world’s first map-based automotive navigation system 'Honda Electro Gyrocator’.

Are the original buildings extant?

The original building is extant, belonging to Honda Motor, Co., Ltd.

Details of the plaque mounting:

The plaque is to be displayed in the exhibition room of Honda Collection Hall.

How is the site protected/secured, and in what ways is it accessible to the public?

The plaque will be displayed in an acrylic showcase in the exhibition room of Honda Collection Hall, which can be accessible to the public.

Who is the present owner of the site(s)?

Honda Motor Co., Ltd.

2-1-1 Minami-Aoyama, Minato-ku, Tokyo, 107-8556 Japan

What is the historical significance of the work (its technological, scientific, or social importance)?

The major historical significance of the world’s first automotive navigation system ‘Honda Electro Gyrocator’ is briefed below.

1)Technological Significance of Development of ‘Honda Electro Gyrocator’

With the rapid advances in automotive technology and roadway environment, the motorization in Japan achieved drastic progress in the 1970’s. However, in those days there was still a hard reality that the automobile could not exert its potential of convenience to the full extent, due to traffic congestions caused by the drastic increase in motor traffic as well as by the sharp rise in personal mobility. Accordingly, the Japanese government launched the project ‘Comprehensive Automobile Traffic Control System’ in 1973, with the aim of equipping a moving vehicle with an innovative function to provide dynamic route guidance on its on-board display with reference to the actual traffic situation.

This project envisioned constructing a regional-scale navigation system provided with hardware capabilities of (i) transmitting the information on the present location and destination of each moving vehicle from its on-board antenna to the center computer via loop antennas embedded in major crossroads, and (ii) visualizing the optimal destination path of a moving vehicle on its on-board display with reference to traffic conditions. However, such a large-scale system necessitated a vast range of too peculiar functions to be implemented for practical use, and moreover it was useless in any area without such an infrastructure. Thus, at that time the automotive navigation technology was barely able to provide a moving vehicle with a routing ability to indicate its destination direction with the use of a magnetic compass.

Honda therefore determined to develop a completely self-contained navigation system, with the intention to equip a moving vehicle with a navigational function to visualize its traveled course including the present location on its on-board CRT (Cathode Ray Tube) display, without relying on any external installation like a radio station. To realize such a function, the most fundamental issue was how to display the present location of a moving vehicle on CRT screen. Thus, even prior to the advent of GPS (Global Positioning System), Honda tried to display the traveled course of a moving vehicle on its on-board CRT screen, referring to the idea inspired by inertial navigation systems which had so far been developed for airplanes [1-3].

Specifically, Honda first developed an elaborate procedure for seeking positioning data on the location of a moving vehicle by detecting its moving distance and direction by means of the ‘mileage’ sensor of Fig. 3 and the ‘gas-rate gyro’ sensor of Fig. 4, respectively, and then constructed a sophisticated mechanism to display on its on-board CRT screen its traveled course including the present location, which was derived from positioning data sought by applying the above procedure to a sequence of its moved locations [3]. Eventually, Honda managed to devise a novel man-machine processing scheme to overlay a transparent road-map sheet on the traveled course displayed on CRT screen. This scheme was successfully evolved into the navigation system ‘Honda Electric Gyrocator’, which was released in 1981 for the first time in the world [1-8].

2)Social Significance of Automotive Navigation Systems from Historical Viewpoint

When tracing the pedigree of map-based automotive navigation systems, we can not help reaching ‘Honda Electro Gyrocator’ released in 1981 [1,5,6,7,8]. Since this navigation system was constructed prior to the advent of GPS, the procedure for seeking positioning data on locations of a moving vehicle was implemented by means of the ‘mileage’ and ‘gas-rate gyro’ sensors on the basis of inertial navigation systems so far developed for airplanes. Its technological practicability of visualizing the traveled course and destination path of a moving vehicle paved the way for map-based automotive navigation [1-8].

Now that the vehicle-positioning technology using gyro and GPS devices has been extensively diffused, and furthermore, the information of traffic congestions has been widely open to the public through the Web, significant benefits have been largely obtained from capabilities of efficient route finding to avoid traffic congestions as well as to raise fuel economy. Moreover, this automotive navigation technology will contribute greatly to the emerging vehicle-to-vehicle and vehicle-to-infrastructure communication, and will enhance the social practicability of ITS (Intelligent Transport System) through safe and efficient driving [7,8].

Thus, basic technologies originally developed for ‘Honda Electro Gyrocator’ contributed primarily to the recent advancement of map-based automotive navigation systems, as well as to the driving safety and environmental integrity [7,8]. Furthermore, the basic idea for seeking positioning data on locations of a moving vehicle was carried over into today’s GPS-based navigation systems, which are continuing to stimulate progressive development to enable more accurate and efficient route finding by adopting innovative gyro and GPS devices [9-15].

What obstacles (technical, political, geographic) needed to be overcome?

The navigation system ‘Honda Electro Gyrocator’ encountered the following three obstacles in its development and operation stages.

Obstacle 1: How to seek and display positioning data on the traveled course of a vehicle.

Obstacle 2: How to view the present location of a vehicle on a road-map.

Obstacle 3: How to correct the traveled course of a vehicle displayed on CRT screen, in case it deviated from a road.

These obstacles were overcome, as outlined below.

Obstacle 1: How to seek and display positioning data on the traveled course of a vehicle.

To construct an automotive navigation system, Honda first developed an elaborate procedure for seeking positioning data on locations of a moving vehicle by means of the ‘mileage’ sensor of Fig. 3 and the ‘gas-rate gyro’ sensor of Fig. 4 [3], as already stated, where it should be added that the reason why these sensors were employed was because existing radio navigation systems, such as LORAN (LOng-RAnge Navigation), Omega System, etc., could not work correctly in urban canyons, underground roads, or tunnels.

Specifically, the ‘mileage’ sensor of Fig. 3 was utilized to emit electric signals to inform the ‘computer unit’ shown in Fig. 1 of the number of wheel revolutions of a moving vehicle with the use of a revolution sensing module composed of ‘Hall’ device [3]. On the other hand, the ‘gas-rate gyro’ sensor of Fig. 4 was employed to emit electric signals to inform the ‘computer unit’ of the directional orientation of a moving vehicle. This gyro was composed of a piezo-vibrator pump for circulating helium gas in the case, an injection nozzle for injecting uniform helium gas, and two hot wires for sensing deviation of the injected gas flow, as shown in Fig. 5 [3]. When a vehicle was moving straight ahead, helium gas hit both hot wires equally to keep them at the same temperature. When the vehicle turned, the flow of helium gas deviated to produce a temperature difference between the two hot wires, which could be detected as a change in output power for determining its directional change of the vehicle [3].

The ‘computer unit’ and ‘display unit’ in Fig. 1 were constructed to run on a 16-bit microprocessor TMS9901 of Texas Instruments Inc., together with 10-kb ROM, 1-kb SRAM, and 16-kb DRAM, which were installed in the circuit board of Fig. 2 [3]. Based on distance signals emitted from the ‘mileage’ sensor and yaw-rate signals from the ‘gas-rate gyro’ sensor, the ‘computer unit’ calculated positioning data on the present location in two-dimensional coordinates and the present directional angle, respectively, and then wrote these data into a data table prepared for storing positioning data. In this way, positioning data on a series of traveled locations were calculated one at a time, which were written into this data table. On the other hand, the ‘display unit’ displayed a picture of traveled course on CRT screen by applying the display processing mechanism to the positioning data just stored in the table, so that the picture could be enlargeable, parallel movable, and rotatable [3].

It should be noticed here that apart from conventional microprocessors, this ‘computer unit’ had the capability not only to deal with precise electric signals on moving distance/direction as input, but also to perform integral/repeated calculations with high accuracy enough to prevent cumulative errors from being significant.

Obstacle 2: How to view the location of a vehicle on a road-map.

Due to the limitation that the moving range of every vehicle should be strictly on roads, its location had to be displayed on a road in a map. Thus, digital road-maps were indispensable for viewing on what road a vehicle is moving. However, even at the end of the 1970’s, the amount of digital data contained in a road-map book necessitated too high volume media to be carried in a vehicle, and hence Honda had to prepare for road-map data separately from the display system. Honda thereby decided to co-develop the transparent road-map sheets, as shown in Fig. 6, with a map-maker of Shobunsha Publications, Inc., on the basis of the 1/250,000-scale maps produced by Geospatial Information Authority of Japan. The transparent map sheets were intended to be overlaid on pictures of traveled courses, so that the driver could view the present location over a transparent road-map. The arrangement of colors for map sheets was decided in contrast to green CRT light, where such prohibited regions as rivers were printed in red. In addition, ‘HONDA Marking Pen’ of Fig. 7 was also co-developed with Mitsubishi Pencil Co., Ltd., which was used for marking destination paths on map sheets [1-3].

In fact, Honda devised a novel processing scheme to overlay a transparent road-map sheet on the picture of a traveled course displayed on CRT screen [1-3]. If any part of the traveled course deviated from a road of a map sheet, the picture of traveled course had to be modified so that it could be completely displayed on roads [3-6], as will be described below.

Obstacle 3: How to correct the traveled course of a vehicle displayed on CRT screen, in case it deviated from a road.

The ‘computer unit’ in Fig. 1 also could enlarge, reduce, and rotate pictures of traveled courses displayed on CRT screen according to a driver’s manual operations. When the driver of a vehicle found that the picture of its traveled course on CRT screen deviated from a road of overlapping map sheet, the driver had to adjust the picture so as to be completely on roads using facilities as shown in Figs. 8 and 9 [1-3].

Two functions were prepared for the process of adjusting the picture of a traveled course displayed on CRT screen. One was a function to enable a driver to adjust vertically, horizontally, and rotationally the picture of a traveled course on CRT screen according to the driver’s operation, as illustrated in Fig. 10. The other was to adjust finely positions of roads on the map sheet by sliding or rotating.

Especially, it should be added here that since the ‘computer unit’ had to meet a driver’s operational demands while executing an extremely heavy task of seeking positioning data on locations of a moving vehicle in real time, this unit could not control properly task switching only by interrupt processing. Thus, the Real Time OS (Operation System) was strongly required, but such a ready-made Real Time OS for the CPU was not yet put into the market, and hence Honda had to develop by itself all systems from application programs to kernel in OS, in a move unusual for an automotive manufacturer [3].

Consequently, novel ideas of introducing transparent road-map sheets to be overlaid on CRT screen, as stated above, realized the map-based route guidance for the first time.

What features set this work apart from similar achievements?

A number of distinctive features of ‘Honda Electro Gyrocator’ are briefed below.

As of 1981, there had been a navigation system that could detect the moving distance and direction of a vehicle by means of ‘wheel revolution’ and ‘geomagnetic’ sensors, respectively. However, this system could not guide a route by map-based navigation, and moreover had the following three disadvantages.

(1) It stopped navigation when a vehicle faced such an obstacle as a river, because it displayed only a direction of its destination.

(2) Large errors could occur when a driver faced big magnetic substances such as iron bridges, railroad crossings, etc., which caused magnetization of the vehicle body, because the system used geomagnetism for direction detection.

(3) A driver could neither recognize an error nor adjust it manually, because information of vehicle’s position existed only in the internal system, to which the driver could not access.

As compared with the above system, ‘Honda Electro Gyrocator’ had distinctive advantages as follows.

(A) This navigation system was map-based, and hence could pursue route finding along every possible path toward its destination to avoid every obstacle.

(B) This system could detect a vehicle’s traveled course including present location without being affected by disturbance or magnetization of the vehicle body, because the ‘mileage’ sensor of Fig. 3 and the ‘gyro’ sensors of Fig. 4 were utilized to search for every possible path.

(C) Even when the driver of a moving vehicle found that its present location or its traveled course displayed on CRT screen deviated from a road of a map sheet, the driver could revise it to be completely on roads.

Eventually, it should be stressed that the concept of these three distinctive features has been carried over into today’s GPS-based navigation systems as global standards [1-3].

References to establish the dates, location, and importance of the achievement: Minimum of five (5), but as many as needed to support the milestone, such as patents, contemporary newspaper articles, journal articles, or citations to pages in scholarly books. You must supply the texts or excerpts themselves, not just the references. At least one of the references must be from a scholarly book or journal article.

[1] http://www.jsae.or.jp/autotech/data_e/14-2e.html. See Appendix 1.

[2] http://www.youtube.com/watch?v=hOqig8rixOU (in Japanese). See Appendix 2.

[3] K. Tagami, T. Takahashi, and F. Takahashi: “Electro Gyrocator” New Inertial Navigation System for Use in Automobiles, SAE Technical Paper, 830659, Feb.-Mar., Detroit, MI, 1983. See Appendix 3.

[4] http://world.honda.com/history/challenge/1981navigationsystem/index.html

[5] http://www.hondanews.info/news/ja/corporate/c810824: Aug. 24, 1981 (Japanese). See Appendix 4.

[6] http://www.hondanews.info/news/ja/corporate/c811217: Dec. 17, 1981 (Japanese). See Appendix 5.

[7] http://www.ieee.org/about/awards/bios/envsaf_recipients.html. See Appendix 6.

[8] http://sites.ieee.org/itss/itss-awards/other/. See Appendix 7.

[9] United States Patent; 4402050: Apparatus for visually indicating continuous travel route of a vehicle, patented on Aug.30, 1983.

[10] United States Patent; 4470124: Method of adjusting the zero-point of rate type sensor, patented on Sep.4, 1984.

[11] United States Patent; 4484284: Apparatus for visually indicating current travel route of a vehicle, patented on Nov.20, 1984.

[12] Japan patent; 62-15920: Apparatus for visually indicating traveled route of a vehicle, submitted on Nov.24, 1981, patented on Apr. 9, 1987 (in Japanese).

[13] Japan Patent; 58-24794: Apparatus for visually indicating traveled route of a vehicle, submitted on Nov. 28, 1979, patented on May 23, 1987 (in Japanese)

[14] Japan Patent; 2-36952: Apparatus for visually indicating traveled route of a vehicle, submitted on Feb. 5, 1980, patented on Aug. 21, 1990 (in Japanese)

[15] Japan Patent; 3-21846: Apparatus for visually indicating traveled route of a vehicle, submitted on Sep. 28, 1980, patented on Mar. 25, 1991 (in Japanese)

Supporting materials (supported formats: GIF, JPEG, PNG, PDF, DOC): All supporting materials must be in English, or if not in English, accompanied by an English translation. You must supply the texts or excerpts themselves, not just the references. For documents that are copyright-encumbered, or which you do not have rights to post, email the documents themselves to ieee-history@ieee.org. Please see the Milestone Program Guidelines for more information.

A number of materials contained in the references cited above, which may make this achievement be more understandable, are shown as appendices in what follows.

Appendix 1: Copy of Reference [1],which shows copy of JSAE WEB site; 240 Landmarks of Japanese Automotive Technology,'Honda Electro Gyrocator'

Appendix 2: Copy of Reference [2], which shows YouTube indicating how to use Honda Gyrocator (in Japanese).

Appendix 3: Figures, system diagram and basic composition of “Honda Electro Gyrocator”, presented in Reference [3].

Appendix 4: Copy of Reference [5], which shows Honda news released in Japan

Appendix 5: Copy of Reference [6], which shows Honda news released in Japan

Appendix 6: Copy of Reference [7], which shows IEEE Awards.

Appendix 7: Copy of Reference [8], which shows IEEE Awards.

Appendix 8: Photos and figures indicating how to use Honda Electro Gyrocator. Photos and figures of Honda Electro Gyrocator.

Please email a jpeg or PDF a letter in English, or with English translation, from the site owner(s) giving permission to place IEEE milestone plaque on the property, and a letter (or forwarded email) from the appropriate Section Chair supporting the Milestone application to ieee-history@ieee.org with the subject line "Attention: Milestone Administrator"