Vehicle navigation system

摘要

A control unit of a vehicle navigation system receives a voice input signal collected from a microphone included in a voice input unit when a synthesized voice is outputted from a voice output unit. An analog-to-digital converter of the control unit converts the voice input signal to a digital signal and a voice recognition circuit performs voice recognition on the digital signal. The control unit compares a result of the voice recognition with voice data. A synthesized voice signal produced by an output control circuit of the control unit via a digital-to-analog convert of the control unit is inputted to the analog-to-digital converter. The voice recognition circuit performs voice recognition on the synthesized voice signal. The control unit compares a result of the voice recognition with voice data. The control unit detects failures based on the results and the detected failures are stored in a data storage.