Toyota Jidosha Kabushiki Kaisha

Shigeki Aoshima

Tomohisa Harada

A vehicle-mounted satellite signal receiving system adopting a satellite tracking system combining gyro tracking and hybrid tracking is disclosed which can correct a sensitivity coefficient for correcting a gyro sensor output signal to make up for a sensitivity error, even when a drift is produced in the sensitivity error. In this system, gyro tracking is caused when the received power level is above a threshold power level. The gyro tracking is done by determining the angular velocity .omega. of an antenna as .omega.=-(.omega.G.times..DELTA.SB+.omega.G from a value obtained by inverting the sign of the product of a gyro tracking angular velocity .omega.G and a sensitivity coefficient .DELTA.SB for dealing with the sensitivity error and a predetermined offset error correction value .omega.G and setting the antenna to .omega.. When .DELTA.SB is inaccurate and a sensitivity error is generated in the gyro sensor output signal, the received power level is reduced. When the received power level becomes lower than a threshold power level LB, the sensitivity coefficient is corrected on the basis of the sense of the angular velocity .omega.S in the hybrid tracking (step tracking) and in the gyro tracking.

Vehicle-mounted satellite signal receiving system

In a vehicle mounted satellite signal receiving apparatus which adopts a satellite tracking system combining a gyro tracking with a hybrid tracking, there is provided a device which can revise an offset error correction value of a gyro sensor, even if there is a drift in the offset error. In this device, gyro tracking is performed when a reception level is a threshold value L.sub.C or more. The gyro tracking is performed by setting an antenna at an angular velocity .omega., which is derived from an equation,.omega.=-.omega.G+.DELTA..omega.G, where -.omega.G is a value resulted from conversion of sign for gyro angular velocity .omega.G, and .DELTA..omega.G is a prescribed offset error correction value. A reception level declines if the offset error correction value .DELTA..omega.G deviates and therefore an apparent offset error arises in the gyro sensor. When the reception level declines below a threshold value L.sub.B, the aforementioned offset error correction value .DELTA..omega.G is revised, basing on the direction of an angular velocity .omega.S which is used in the hybrid tracking (or step tracking).

Vehicle-mounted satellite signal receiving apparatus

A sound processor (12) calculates first through third parameters according to an LPC cepstrum, a primary delta cepstrum and a secondary delta cepstrum. The first parameter catches a static characteristic, the second parameter catches a dynamic characteristic with time, and the third parameter catches a locally dynamic characteristic with time. A word dictionary (14) stores first through third parameters for a standard pattern. Hence, a DP matching unit (16) recognizes a voice based on a distance between an input voice of the three parameters and the standard pattern.

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Susono, Japan

Shigeki Aoshima