Nippondenso Co., Ltd.

Kazushi Akutsu

Kazuaki Minami

Koshi Hasebe

Kunio Miura

Takashi Ono

Shinzo Totani

Hajime Mikuni

Hitoshi Ichikawa

Kazuo Muramoto

Shinji Ohyama

Susumu Akiyama

Yuji Hirabayashi

Katsuhiro Ina

Kiyohumi Kage

A correction apparatus for an azimuth calculation system which includes an azimuth sensor mounted on a moving body for producing two mutually perpendicular magnetic field components relative to the earth's magnetism acting thereon, and wherein the azimuth sensor is moved in a full circle so that an azimuth circle is formed by the two magnetic field components. The correction apparatus is arranged to store a plurality of interspaced X-axis lines in parallel with the abscissa of a right-angled coordinate and a plurality of interspaced Y-axis lines in parallel with the ordinate of the coordinate, to determine maximum and minimum values respectively defined by intersections of the azimuth circle with the X-axis lines and maximum and minimum values respectively defined by intersections of the azimuth circle with the Y-axis lines, to determine first and second center values of the azimuth circle based on each mean value of the first-named maximum and minimum values and the second-named maximum and minimum values, to correct the magnetic field components respectively in accordance with the first and second center values, and to calculate a direction of the moving body on a basis of the corrected magnetic field components.

Correction apparatus for an azimuth calculating system

Disclosed is an azimuth determination apparatus attached to a motor vehicle for determinating the forward direction of the vehicle. The azimuth determination apparatus includes an azimuth sensor for generating orthogonal first and second signals indicative of the forward direction of the vehicle. Two azimuth vectors are obtained on the basis of the orthogonal first and second component signals, first components of the two azimuth vectors being maximum and minimum. The determination is made in terms of the fact that the difference between second components of the two azimuth vectors is below a predetermined value. In accordance with the determination, the orthogonal first and second component signals are corrected on the basis of said two azimuth vectors so that the accurate moving direction of the motor vehicle can be obtained irrespective of the remanence of the vehicle.

Azimuth determination apparatus

An azimuth calculation apparatus includes an azimuth sensor mounted on a moving body for detecting a direction of the moving body, the azimuth sensor having an excitation winding wound on an annular magnetic core and a pair of output windings wound on the core perpendicularly relative to one another to produce first and second output signals therefrom in response to energization of the excitation winding. The calculation apparatus is arranged to detect a temperature of the azimuth sensor and to determine a pair of correction values based on the detected temperature of the azimuth sensor so as to correct each value of the first and second output signals from the output windings to an optimal value for calculating the direction of the moving body in dependence upon the corrected output signals from the output windings.

Azimuth sensor which corrects azimuth circle diameter and center for

In a navigator for vehicles, a distance sensor detects a distance travelled by a vehicle and a heading sensor detects a direction of travel of the vehicle. In response to the detection signals from the sensors a microcomputer computes the present position of the vehicle and generates a position signal. In accordance with the position signal from the microcomputer and the selection of display selection switches a display tube gives a graphic display of a road map or a character display of a road map data.

Navigator for automotive vehicles

In a vehicle-mounted navigator, a control unit reads map data from a memory unit and displays a corresponding road map on a CRT display unit. In response to signals from a distance sensor and a direction sensor, the present position in relation to the running of the automotive vehicle is computed to display by superimposition the present position on the road map display of the display unit. When the computed present position has reached to a predetermined portion of an adjacent area, the map data of the road map adjacent to the road map on display is read from the memory unit and a corresponding road map is displayed on the display unit manually or automatically. In accordance with this updated display, the present position display is moved to a corresponding position on the updated road map display.

Vehicle-mounted navigator

An automotive navigator using a microcomputer displays a car position by a cursor on a road map displayed on a CRT screen. The navigator uses a cassette tape which stores a plurality of road map data and several kinds of reduced map data and expanded map data. It also uses a group of manual switches including a switch for changing the displayed area, a switch for selecting an expanded map or reduced map and a switch for moving the cursor position. Necessary data are displayed on the screen by the state of each switch. A region corresponding to the cursor position is displayed by the expanded map.

Electronic navigator for automotive vehicles

In a navigation system arranged to display a road map in accordance with road map information from a cassette tape, and the present location of a motor vehicle equipped with the navigation system, a cassette tape distinguishing circuit is provided to a cassette tape player which picks up the road map information from a predetermined cassette having a window at given portion of the cassette housing. A switching circuit is responsive to the cassette tape distinguishing circuit so that the output data of the cassette tape is processed to display a given map only when a cassette carrying road map information is loaded in the cassette tape player. In the case a normal cassette carrying audio signals, such as music, is loaded the picked up audio signal is transmitted to an amplifier so that sound reproduction is effected. Thus, a single cassette player can be used in common as both a part of the navigation system and a part of a sound reproduction system.

Navigation system for use with an automobile and reading unit for the

A mobile navigator comprises a distance detector for generating a running distance signal, an azimuth detector for generating a progression azimuth detecting signal, a CRT display for indicating the current position of an automotive vehicle, a microcomputer for calculating the current position of the vehicle from the distance detecting signal and the progression azimuth detecting signal and supplying the current position signal to the display, and a memory in which is stored a plurality of map data, earth's magnetic field declination information different for each area in association with the map data, and earth's magnetic field strength information.

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Kariya, Japan

Kazushi Akutsu