Equos Research Co., Ltd.

Kabushikikaisha Equos Research

Toyota Jidosha Kabushiki Kaisha

Mitsubishi Electric Corporation

Hiroyuki Yamakawa

Yasuo Ito

Naoki Gorai

Kenichiro Sato

Takashi Sugawara

Satoshi Kitano

Kenichirou Satou

Shinji Ichikawa

Koki Hayashi

Masaaki Kamikawa

Katsuya Maeda

Naoto Uenakai

A power transmission system transmits electric energy to a secondary resonator having a secondary resonator coil through an electromagnetic field of a predetermined frequency from a resonator having a resonator coil and reduces noise using two noise cancellation resonators with one predetermined frequency and its higher harmonic component set as noise reduction target frequency. The system includes, as two noise cancellation resonators, a first noise cancellation resonator including a first noise cancellation resonator coil and has a resonance frequency higher than the noise reduction target frequency by a first shift frequency determined according to a coupling degree between the resonator coil and first noise cancellation resonator coil and second noise cancellation resonator including a second noise cancellation resonator coil and has a resonance frequency lower than the noise reduction target frequency by a second shift frequency according to coupling degree between the resonator coil and second noise cancellation resonator coil.

Power transmission system

A power transmission system that can prevent a plunge in power transmission efficiency even when there is a positional shift of a power reception antenna with respect to a power transmission antenna. A power transmission system includes: a power transmission antenna that includes a wound power transmission coil that is placed on the ground; a power reception antenna that is disposed in such a way as to face the power transmission antenna, includes a wound power reception coil, and receives electric energy from the power transmission antenna via an electromagnetic field, wherein an area of a first projection plane that is formed by the power transmission coil in a vertical direction with respect to a horizontal plane is larger than an area of a second projection plane that is formed by the power reception coil in the vertical direction with respect to the horizontal plane.

The antenna coil unit includes a main coil and an auxiliary coil electrically insulated from the main coil, the auxiliary coil being arranged at a position in which an induction current is produced by a magnetic field produced by an electric current flowing through the main coil. The auxiliary coil is configured in a state in which a frequency deviating by a predefined amount in a predefined direction from a target frequency predefined within a harmonic component of the fundamental component of an electromagnetic wave produced by the electric current flowing through the main coil is taken as a resonance frequency. The direction and amount are such that the phase of an alternating-current current flowing through the auxiliary coil is in an opposite-phase state, which is opposite the phase of the harmonic component of an AC current flowing through the main coil.

Antenna coil unit

An electric power transmission system can include: a power transmission antenna that constitutes a series resonator with an inductance component of L1 and a capacitance component of C1, and to which AC power is input; a power receiving antenna that constitutes a series resonator with an inductance component of L2 and a capacitance component of C2, and which receives electromagnetic energy from the power transmission antenna via electromagnetic fields; a rectifying unit that rectifies an output of the power receiving antenna to output DC power; and a load to which an output of the rectifying unit is input, wherein, at times including when a coupling coefficient between the power transmission antenna and the power receiving antenna is k, if a load resistance value is R, the following relationships are established: 

Electric power transmission system with power transmission and receiving antennas

An electric power transmission system may include: a power transmission antenna that constitutes a series resonator with an inductance component of L1 and a capacitance component of C1, and to which AC power is input; a power receiving antenna that constitutes a series resonator with an inductance component of L2 and a capacitance component of C2, and which receives electromagnetic energy from the power transmission antenna via electromagnetic fields; a rectifying unit that rectifies an output of the power receiving antenna to output DC power; and a load to which an output of the rectifying unit is input, wherein, when a coupling coefficient between the power transmission antenna and the power receiving antenna is k, if load resistance value R is used in a range that satisfies Rmin&#x2266;R&#x2266;Rmax, the following relationships are established: 

In order to provide a noise cancellation resonator that is highly effective in reducing noise, a noise cancellation resonator of the present invention is characterized by including: a noise cancellation resonator coil with an inductance component of L; and a noise cancellation resonator capacitor with a capacitance component of C, wherein the noise cancellation resonator has a resonance frequency that is calculated by adding a shift frequency that is determined based on a degree of coupling between a main resonator coil and the noise cancellation resonator coil, to a predetermined frequency of an electromagnetic field generated by a main resonator that is a source of noise and includes the main resonator coil.

Noise cancellation resonator

Provided is an antenna coil capable of forming a magnetic field in a desired direction in an efficient manner, while suppressing leakage of magnetic flux into a space other than the space in which the magnetic field is formed. The antenna coil includes a main coil portion formed by winding a length of conductor wire around a first reference axis and an auxiliary coil portion formed by winding the conductor wire around a second reference axis. The second reference axis is set to intersect the magnetic flux of the main coil portion at an axial end of the auxiliary coil portion. The main coil portion and the auxiliary coil portion are connected to together form a closed circuit.

Antenna coil comprising plurality of coil portions

A power transmission system for transmitting electrical energy from a transmission antenna to a reception antenna via an electromagnetic field, including: an inverter for converting DC voltage into AC voltage having a prescribed frequency and outputting the AC voltage; a transmission-side control unit for performing a control for keeping the drive frequency of the inverter at a prescribed frequency, controlling the voltage of the DC voltage inputted into the inverter, and controlling to keep the power value outputted from the inverter constant; a transmission antenna into which the inverter inputs the AC voltage; a rectifier for rectifying the output from the reception antenna into DC voltage; a step-up/step-down unit for stepping up or down and then outputting the DC voltage from the rectifier; a battery charged by the output from the step-up/step-down unit; and a reception-side control unit for controlling the step-up/step-down unit and charging the battery most efficiently.

Electric power transmission system

Communication navigation system

A communication route guidance system provides exchange of data between an information center and each of a plurality of mobile units such as vehicles. The information center has the latest road data and searches it to prepare recommended route guidance data in response to a request from the mobile unit. The reccommended route guidance data is divided into a plurality of data segments, each usable as an independent guidance instruction in the mobile unit. The mobile unit has stored therein road data similar to the road data in the information center and determines if data communication with the information center is available. In a case where the mobile unit can not communicate with the information center, the mobile unit prepares route guidance based on the road data stored in the mobile unit. It thereby becomes possible to guide the user even in the case that the mobile unit can not communicate with the information center. Even in a case where a communication link is disrupted during transmission of route guidance data to the mobile unit, the mobile unit can effectively prepare whole route guidance data in combination with already-received route guidance data and additionally prepared route guidance data by reference to the road data stored in the mobile unit because the already received route guidance data is structured to be usable independently.

Communication route guidance system

A navigation system includes a navigation center and at least one moving body. The navigation center of the navigation system comprises memory means for storing navigation information; updating means for constantly updating the navigation information stored in the memory means; route searching means for setting a route from a current position of the moving body to a destination on the basis of the newest navigation information updated by the updating means; dividing means for dividing the searched route into at least two portions; extracting means for extracting navigation data concerning at least a head portion of the divided route from the memory means; transmitting means for transmitting to the moving body the extracted navigation data; and control means. After transmitting the navigation data for the head portion to the moving body and before transmitting navigation data for a remaining route, the control means controls each of the route searching means, the dividing means, the extracting means and the transmitting means so that each means performs the respective processes. This arrangement enables a user of the moving body to be provided with route guidance which is conducted using the navigation data formed based on the newest navigation information that reflects various road conditions.

Navigation method, navigation system, and information communications apparatus used in the navigation system

A navigation system includes a navigation center and a plurality of navigation apparatuses each of which has a data storage that stores various information. In this navigation system, data (coordinate data of each of traveling intersections) concerning a recommended route is transmitted from the navigation center to the navigation apparatus, and then route guidance is carried out in the navigation apparatus using the data received from the navigation center. In the case where the navigation apparatus has intersection data for an intersection specified by the data received from the navigation center, the navigation apparatus extracts the intersection data for the intersection from the data storage. Further, in the case where the navigation center does not have intersection data for an intersection specified by the data received from the navigation center, the navigation apparatus establishes the intersection as a newly-built intersection on the recommended route. Then, the navigation apparatus produces route guidance data (which is used for providing route guidance to a user) using the extracted intersection data, and/or intersection data concerning the established newly-built intersection in addition to the information in the data storage.

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Hokkaido, Japan

Hiroyuki Yamakawa