Identification of the Driver's Interest Point using a Head Pose Trajectory for Situated Dialog Systems

This paper addresses issues existing in situated language understanding in a moving car. Particularly, we propose a method for understanding user queries regarding specific target buildings in their surroundings based on the driver's head pose and speech information. To identify a meaningful head pose motion related to the user query that is among spontaneous motions while driving, we construct a model describing the relationship between sequences of a driver's head pose and the relative direction to an interest point using the Gaussian process regression. We also consider time-varying interest point using kernel density estimation. We collected situated queries from subject drivers by using our research system embedded in a real car. The proposed method achieves an improvement in the target identification rate by 14% in the user-independent training condition and 27% in the user-dependent training condition over the method that uses the head motion at the start-of-speech timing.