Toyota Jidosha Kabushiki Kaisha

Kabushiki Kaisha Toyota Chuo Kenkyusho

Denso Corporation

Other

Masaru Ogawa

Kunitoshi Nishikawa

Toshiaki Watanabe

Shin-ichiro Matsuzawa

Tomohisa Harada

Koji Suzuki

Kento Nakabayashi

Kazuo Sato

Atsushi Kawakubo

Isahiko Tanaka

Makoto Ohkado

Koji Takeuchi

Tetsuya Katayama

Eiji Teramoto

A radar system includes an arithmetic processing unit, which calculates the second derivative of the intensity of a reflected wave and determines whether a target is an upper structure or a vehicle, based on the second derivative. Alternatively, the arithmetic processing unit decomposes the waveform of the intensity of the reflected wave into frequency components and determines whether the target is an upper structure or a vehicle, based on the intensity of a predetermined frequency component.

Radar system and detection method

An antenna cover () for a radar () for a vehicle has a rectangular parallelepiped shape, having a flat cover top () that faces a microstrip antenna () of the radar () and a sidewall () that covers the microstrip antenna () sideways. The sidewall () is located out of the range where the electromagnetic waves to be received by the microstrip antenna () are directly received. An inner face () of the sidewall () is at a right angle to the cover top (). An outer face () of the sidewall () is at a constant angle &#x3b8; larger than 0 degree but smaller than 90 degrees, to the inner face () of the sidewall (). The sidewall () is structured such that its thickness increases toward the side where the microstrip antenna () is present.

Antenna cover

A radar system includes an arithmetic processing unit, which sends a warning command to a warning device when a local minimum point of the intensity of the reflected wave from a target within a predetermined detection range is detected. By determining whether it is necessary to send a warning command based on whether there is a local minimum point of the intensity within the detection range, it is made possible to determine whether it is necessary to send a warning command more quickly as compared to the conventional system.

A radar apparatus forming a series-feed array-antenna includes an array antenna having transmission/reception antennas, and each antenna includes a plurality of antenna elements arrayed with feed-lines to be series-connected each other. A calibration line is disposed between the transmission antenna and the reception antenna via a switch which connects or disconnects the calibration line. The signal having a phase shift is transmitted via the calibration line when the switch connects the calibration line and an amount of phase shift from the signal transmitted via the calibration line is calculated based on a reference phase at the transmission antenna thereby calibrating the phase shift.

Radar apparatus provided with series-feed array-antennas each including a plurality of antenna elements

The antenna includes a first ground plate, a first dielectric substrate formed on the first ground plate, a transmission line made of a conductive material formed on the first dielectric substrate, and a plurality of antenna elements electromagnetically coupled to the transmission line. The transmission line is constituted of at least one first line serving as a resonator having a resonator length equal to (2n&#x2212;1)/2 times (n being a positive integer) a guide wavelength of the transmission line and a plurality of second lines each having an electrical length longer than half the guide wavelength, the first and second lines being disposed alternately at predetermined intervals. Each of the antenna elements is electromagnetically coupled to a corresponding one of the second lines.

Antenna

A radar system includes radars and a controller. The controller controls waveform patterns of the radars. As a signal processing unit of each of the radars receives an instruction from the controller, the signal processing unit selects a frequency modulation pattern of a VCO between an FM-CW mode and a CW mode stored in a waveform memory to perform mode switching, and then outputs a radio wave from a transmission antenna. Then, the controller instructs each signal processing unit for a frequency modulation pattern of each radar or an output timing of each pattern so that a time, at which continuous wave signals output from the radars have the same frequency, is not continuous.

Radar system

A feed probe (), a semicylindrical sub-reflector () forming a primary radiator together with the feed probe (), and a main reflector () arranged such that mirror surfaces of said main reflector () and the sub-reflector face across the feed probe () are all disposed on a ground plate (a recfector face) (). The main reflector () has a predetermined focal point or focal line on which the feed probe () is located, and is mounted on the ground plate () at a predetermined installation angle &#x3b8;. A converter () for converting linearly and circularly polarized waves is provided on the mirror surface of the main reflector (). The converter () is composed of a plurality of grooves () and ridges () formed between the grooves, so that a wave component orthogonal to the grooves is reflected at the bottom of the grooves while a wave component parallel to the grooves is reflected on the ridge surface, thereby causing a phase difference according to the height H of the grooves when a radio wave is reflected on the main reflector to thereby perform linear to circular polarization conversion.

Antenna system

There is provided an antenna system applicable to an in-vehicle satellite tracking antenna system. A feed probe (,) is inserted into a ground plate (,) from a lower surface of the ground plate (,) toward an upper surface to protrude from the upper surface. A semicylindrical sub-reflector (,) forming a primary radiator together with the feed probe (,) is arranged on the upper surface of the ground plate (,) in the vicinity of the feed probe (,), and a main reflector (,) is arranged on the ground plate (,) such that mirror surfaces of the reflectors face to each other across the feed probe (,). The main reflector (,) is parabolic in at least one axis, and has a predetermined focal point or a predetermined focal line. The main reflector (,) is standing on the ground plate (,) such that the feed probe (,) is positioned on the focal point or the focal line, which is mounted on the ground plate (,) at a predetermined installing angle &thgr; so that an elevation angle of the antenna is directed in a direction that receives radio waves or a direction that radiates radio waves. Tracking of the antenna system with respect to an azimuth is carried out by turning the ground plate (,) in a fashion being out of contact with the feed probe (,). By virtue of the above construction, the antenna system can be downsized or given a low profile.

A directional beam antenna device includes: an antenna supporting member which is supported on a base in such a manner as to be rotatable about a first rotational axis; an antenna portion which is supported on the antenna supporting member in such a manner as to be rotatable about a second rotational axis which is perpendicular to an antenna aperture and is inclined at a first angle with respect to the first rotational axis, the direction of an antenna beam being inclined at a second angle with respect to the second rotational axis; a first driving unit for rotating the antenna supporting member about the first rotational axis with respect to the base; and a second driving unit for rotating the antenna portion about the second rotational axis with respect to the antenna supporting member. A directional beam controlling apparatus is provided with a controlling unit for controlling an elevation angle of the antenna beam to a target value by causing the second driving unit to rotate the antenna portion with respect to the antenna supporting member, and for controlling an azimuth angle of the antenna beam to a target value by causing the first driving unit to rotate the antenna supporting member with respect to the base.

Directional beam antenna device and directional beam controlling

A control portion performs gyro control at control intervals of .DELTA.t, by using -.omega.G, which is obtained by inverting the polarity of an angular rate .omega.G outputted from an angular rate sensor portion. On the other hand, a receiving level is detected at constant control intervals of .DELTA.T (=M.DELTA.t: M is an integer). The rotation of an antenna portion is controlled by using .omega.s, if the receiving level has increased, or by using -.omega.s, if the receiving level has decreased, i.e. by step track control. By accumulating the control amount .+-..omega.s for a predetermined long time period of N.DELTA.T, accumulation of an error contained in each angular rate .omega.G is obtained. The accumulated value is then divided by N to calculate an error .DELTA..omega.G contained in .omega.G. This error .DELTA..omega.G is used to compensate the actual error, so that the gyro control can be made more accurate.

Tracking antenna system

In an annular microstrip antenna element, an annular radiant conductor plate is mounted on a ground conductor plate via a dielectric layer. A coaxial transmission line is provided, whose external conductor is connected to the ground conductor plate, and whose central conductor is connected to the radiant conductor plate, via a feeding point, with a pair of microstrip lines. The pair of microstrip lines extend from the feeding point to two connecting points on the radiant conductor plate, forming an angle between them like a V shape. By varying the angle, it is possible to adjust the input impedance of the annular microstrip antenna element at the feeding point, so that impedance matching with the coaxial transmission line is achieved. In a radial line antenna system comprising a plurality of the antenna elements, the antenna elements are mounted on concentric circles with a constant space between the adjacent antenna elements, thereby reducing undesirable electromagnetic coupling.

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Seto, Japan

Masaru Ogawa