Vehicle navigation apparatus

摘要

A vehicle navigation apparatus wherein a detection unit comprising a gyro sensor operates by receiving a power supply from an onboard device. The onboard device comprises: a first control circuit which functions as a navigation apparatus; and a second control circuit which activates in a shorter time period (ΔT3) than the first control circuit, and starts the power supply to the detection unit, and collection of vehicle information. The detection unit comprises a zero point correction unit which samples the gyro voltage for a prescribed interval (ΔT0) after the power supply is started by the second control circuit. On the basis of the vehicle information which is transmitted after the activation of the first control circuit, the zero point correction unit determines whether the vehicle was stopped during the sampling interval, and sets a zero point for the gyro sensor on the basis of the gyro voltage sampling result

主权项

1. A vehicle navigation apparatus comprising:
an in-vehicle unit, the in-vehicle unit includes a first processor and a second processor, the first processor is configured to display a road map containing a vehicle position on a display portion to provide travel guidance for a vehicle; and a detection unit adapted to operate by being supplied with power from the in-vehicle unit, and detects a current position and a travel direction of the vehicle and outputs the current position and the travel direction to the in-vehicle unit, wherein the in-vehicle unit includes: a first control portion, comprises the first processor, the first processor is further configured to: communicate with the detection unit to transmit vehicle information to the detection unit and to acquire the current position and the travel direction from the detection unit and provide the travel guidance; and a second control portion, comprising the second processor, the second processor is further configured to: in response to start of power supply to the in-vehicle unit, start up in a shorter time than the first control portion, and start supplying the power to the detection unit and collecting the vehicle information, wherein
when the first control portion starts up later than the second control portion in response to the start of the power supply to the in-vehicle unit, the first control portion is further configured to transmit, during a period associated with the later startup of the first control portion, to the detection unit the vehicle information that is collected by the second control portion; wherein the detection unit includes:
a gyro sensor that detects an angular velocity applied to the vehicle; anda third processor, the third processor is configured to set, by a zero point correction portion, a zero point of an output of the gyro sensor, wherein
when the detection unit starts up in response to the power supply from the in-vehicle unit, the zero point correction portion
samples the output of the gyro sensor,determines whether or not the vehicle is in a stop state during sampling of the output of the gyro sensor based on the vehicle information transmitted from the first control portion, andsets the zero point of the output of the gyro sensor based on a sampling result when the vehicle is in the stop state during the sampling.