| 摘要 |
PURPOSE: To detect the degradation of road environment without using an exclusive sensor or judge the failure of a distance sensor without needing two distance sensors so as to secure the reliability of control while reducing cost. CONSTITUTION: A travel control device for an automobile is provided with a laser radar for detecting inter-vehicle distance between an own vehicle and a preceding vehicle and performs auto-cruise according to the inter-vehicle distance detected by the laser radar. The output power of the laser radar is measured, and outside air temperature is estimated on the basis of the temperature characteristic of output power. When the outside air temperature is in an area of not lower than the temperature where the output power of an optical distance sensor is lowered to the specified value or less, or in an area of the road surface freezing temperature or lower, the road environment is judged to be bad, and auto-cruise is stopped. Reflecting bodies are disposed being spaced by the specified distance in front of the laser radar, and laser beams are emitted to the reflecting bodies from the laser radar to measure the distance and reflecting quantities between both reflecting bodies. When at least either one of the measured distance and reflecting quantity is out of an allowable range, the failure of the laser radar is judged, and auto-cruise is stopped. |
