Denso Corporation

Nippon Soken, Inc.

So-ken Corporation

Tohoku University

Akira Takaoka

Takashi Saitou

Takatoshi Sekizawa

Nobuya Watabe

Masashi Mori

Youichirou Suzuki

Munenori Matsumoto

Yuukou Murase

Kenichiro Sanji

Yuuji Kakuya

Yoshie Sugiura

Fan Wang

Noriaki Okada

Tomohiro Kuno

Shiro Koide

Hideki Saito

Hiromichi Naito

Ichiro Shigetomi

Takafumi Nishi

Hiromichi Naitoh

Tomotsugu Sekine

Koji Ito

Koichi Ito

Hideaki Ishihara

Yoichiro Suzuki

Taiji Abe

Toshihiro Wakamatsu

Masahiro Sugiura

Kouji Yamashita

Akihiko Hayashi

Toshifumi Shimoda

Hiroki Kuwano

Hidenori Wada

Hirokazu Ooyabu

Yoshinori Hanai

Tohru Yamaguchi

A power generation device is provided. A weight may vibrate in one direction as an axial direction in response to an external vibration. A beam may be arranged in at least one side with respect to the weight in the axial direction of the weight, and vibrate together with the weight. A piezoelectric element may be mounted on the beam. A guide may include a hollow guiding a movement of the weight in the axial direction. A stopper may be included in the weight. The stopper may restrict an amount of the movement of the weight in the axial direction within a predetermined amount. A stopper wall may stop the movement of the weight in the axial direction by contacting with the stopper.

Power generation device

In order to detect a road surface condition, a road surface condition estimation device extracts a detection signal of a portion that detects vibration in a tire tangential direction in a vibration detection and power generation unit which is in a ground contact section, for example, a vibration power generation element. In this case, it is identified that the vibration detection and power generation unit is in the ground contact section, based on whether a centrifugal force acting on the vibration detection and power generation unit is generated, or not, and it is identified that a time when no centrifugal force is generated is in the ground contact section. As a result, even if a pulse level of an output voltage of the vibration detection generation unit changes according to a traveling speed of the vehicle, the ground contact section can be accurately identified.

Road surface condition estimation device

A road surface condition estimation device extracts a detection signal of a vibration power generation element during a ground contact section to detect a road surface condition. A threshold used for determination of the ground contact section is variable according to a traveling speed of a vehicle. As a result, even if a pulse level of an output voltage of the vibration power generation element changes according to the traveling speed of the vehicle, the threshold corresponding to the change can be set. The ground contact section is determined with the use of the above thresholds, thereby being capable of performing the determination with high accuracy. Therefore, the road surface condition can be detected with high accuracy based on the ground contact section determined with high accuracy.

A vehicle control device including a tire-side device and a vehicle-side device is provided. The tire-side device includes a vibration detection unit that outputs a detection signal corresponding to a magnitude of vibration of a tire, a signal processing unit that generates &#x3bc; data representing a friction coefficient between the tire and a road surface by processing the detection signal, and a transmitter that transmits the &#x3bc; data. The vehicle-side device includes a receiver that receives the &#x3bc; data and a travel control unit that estimates the friction coefficient based on the &#x3bc; data, acquires a braking distance of the vehicle based on the friction coefficient, and controls acceleration and deceleration of the vehicle based on the braking distance.

Vehicle control device

A road surface condition estimation device includes a tire side device and a vehicle side device. The tire side device includes a vibration detection unit attached to a back surface of a tire tread and outputting a detection signal indicating a tire vibration magnitude, a signal processing unit, and a transmitter. The signal processing unit extracts a ground contact duration during which a portion of the tread corresponding to an arrangement position of the vibration detection unit is in contact with a ground, and calculates a high frequency component level of the detection signal detected during the ground contact duration as road surface condition data. When the ground contact duration is ended, a transmission trigger is transmitted to the transmitter and the transmitter transmits the road surface condition data. The vehicle side device estimates a road surface condition of the travelling road based on the road surface condition data.

A road-surface-condition estimation device is configured by a tire-side device and a vehicle-side device so as to grasp a road surface condition based on road surface condition data transmitted from a tire-side device. As a result, the road surface condition or a road surface &#x3bc; of a traveling road surface of a vehicle can be accurately detected, and a more accurate lane keeping control can be performed according to the detection result. In particular, since the tire-side device estimates the road surface condition by detecting the vibration of a ground contact surface of the tire, the road surface condition can be estimated more accurately. Therefore, the more accurate lane keeping control can be performed.

Lane keeping control system

A road surface condition estimation device includes a tire side device and a vehicle side device. The tire side device includes a vibration detection unit outputting a detection signal indicating a tire vibration magnitude, a signal processing unit, and a transmitter. The signal processing unit extracts a ground contact duration during which a portion of the tread corresponding to an arrangement position of the vibration detection unit is in contact with a ground, calculates a high frequency component level of the detection signal detected during the ground contact duration, counts cumulative rotation number of the tire, and corrects the level of the high frequency component based on the cumulative rotation number of the tire. The transmitter transmits corrected level of the high frequency component as road surface condition data. The vehicle side device estimates a road surface condition of the travelling road based on the received road surface condition data.

An erroneous start is controlled based on vibrations of a tire, irrespective of a poor visibility or an algorithm of an image processing. A tire-side unit detects a vibration of a tire when the tire has collided with a wheel stop or the like, and outputs collision data to a vehicle-side unit. The vehicle-side unit determines an erroneous start of the vehicle. Therefore, the erroneous start of the vehicle can be controlled without being affected by the poor visibility or the algorithm of the image processing as in a case of utilizing a camera or a radar.

Vehicle erroneous start control device

A tire device includes a vibration power generating element, a signal processing unit, and a transmitter. The vibration power generating element is arranged inside a tire and outputs a voltage corresponding to a time variation of a vibration generated in a tread of the tire. The signal processing unit is disposed inside the tire and performs signal processing on the voltage outputted from the vibration power generating element. The transmitter is arranged inside the tire and sends data subjected to the signal processing in the signal processing unit to a device provided outside the tire. The signal processing unit and the transmitter are driven by power generated in the vibration power generating element.

Tire device

In a vehicular control device, an operating intention detection unit is disposed on a tire or wheel rim of a vehicle to detect an operating intention of a user relative to an opening/closing body of the vehicle. An operating intention acquisition unit is disposed on the vehicle body of the vehicle to acquire the operating intention. An ID code acquisition unit acquires, from a mobile device carried by the user, an ID code that identifies the user or the mobile device. An ID code determination unit determines whether the ID code is correct. The condition establishment determination unit determines, based on the operating intention of the user and on the result of ID code determination, whether an output condition for outputting operating instruction information that designates an operation of the opening/closing body is established. An output unit outputs the operating instruction information when the output conditions are established.

Vehicular control device

The communication system includes a first communication device, a second communication device, and a third communication device. The first communication device outputs a high frequency alternating current power, and a power receiving circuit of the second communication device receives the high frequency alternating current power via a second antenna. A power line is connected between the second antenna and the power receiving circuit. A first power line has a first semicircle portion and a second power line has a second semicircle portion. The first and second semicircle portions are combined together to provide a loop-shaped antenna. The third communication device receives the high frequency alternating current power output from the loop-shaped antenna. At least two of the first, second, or third communication devices transmit or receive communication signals using respective antennas. The first and second power lines are twisted with each other at a portion other than the loop-shaped antenna.

Communication system

Data representing a ground contact time of a tire is transmitted from a tire side device, and received by a vehicle side device to calculate the ground contact time of the tire, to thereby calculate a ground contact length of the tire at that time. In a situation where a tire air pressure may change such as a tire exchange, the ground contact length at that time is set as a reference ground contact length, and a determination reference value is set on the basis of the reference ground contact length. As a result, the relative determination reference value corresponding to the tire type can be set, and a variation of the reduction rate of the tire air pressure when it is determined that the tire air pressure is reduced can be reduced. As a result, the reduction in the tire air pressure can be detected with high precision regardless of the tire type.

Tire condition detection device

In an antenna, a first element is connected to a GND of a feeder, on the same plane as a GND of a wireless circuit, and isolated from the GND of the wireless circuit. A second element is on the same plane as the GND of the wireless circuit and a first end connected to the first element and a second end as an open end. The third element has a first end connected to a power source of the feeder and located in a region occupied by the first element perpendicularly to the first element so that its first end source faces down. The fourth element has a first end connected to a second end of the third element and a second end as an open end, is parallel to the first element, and is perpendicular to a line connecting the first and second ends of the second element.

Antenna

A communication device changes an applied voltage output from a voltage circuit, and allows a capacitance measuring device to measure the respective capacitance values of a variable capacitance element before and after a change in the applied voltage. The communication device calculates a voltage correction value for correcting an initial variation of the capacitance value of the variable capacitance element using the respective capacitance values of the variable capacitance element before and after the change in the applied voltage, and respective applied voltage values before and after the change, and a correction voltage for canceling the initial variation in the capacitance value of the variable capacitance element, and outputs the correction voltage from the voltage circuit.

Communication device and method of adjusting applied voltage for matching circuit

An opening area between twisted portions of a pair of twisted wires is arranged to be opposite to an opening area of an aperture antenna of each of communication apparatuses. Thus, the use of the pair of twisted wires permits division of electric power among the communication apparatuses and also communication of signals. In particular, among the opening areas between the twisted portions of the pair of twisted wires, only an opening area, which is in between the twisted portion and the twisted portion and is opposite to the aperture antenna, is formed to be larger than a different opening area. This provides a vehicular power line communication system and a transmitter in the system; the system strengthens electromagnetic induction connection between the transmitter and the receiver to permit power line communication.

Growing community of inventors

Okazaki, Japan

Akira Takaoka