Biologically-inspired time and location of impact prediction from optical flow

We investigated the use of optical flow to predict the time and location of impact of an incoming object. By examining local patterns of optical flow, we make predictions on an object's trajectory with respect to a stationary observer, and its time-to-contact with the observer's (assumed planar) body. Such a cue may serve as inputs to motor responses for reactive threat avoidance, or object interception (such as catching a ball). The presented approach is based on the observed behaviour of neurons in the F4 region of the pre-motor cortex of primates and it is part of a larger project which aims at modelling multi-sensory neurons and their contribution to reaching behaviour on the iCub humanoid platform. We present preliminary experimental results of a computation model of F4's visual responses using real image sequences acquired from the robot, and demonstrate their application in a real-time threat detection/prediction system.