Previous experiments using a biohybrid fly-robotic-interface (FRI) revealed that the neural activity of an identified directional-selective cell in the blowfly motion vision system indicates proximity to the walls of an experimental area. For a constant turning radius of the FRI along an oscillatory trajectory, the spike rate of the H1-cell was inversely proportional to wall distance. We have now implemented a distance estimation algorithm on a small 2-wheeled robot, based on a parsimonious model of directional motion detection in flies and tested its performance under different conditions. Applied to monocular and binocular image motion captured with an on-board video camera, the algorithm enabled the avoidance of collisions at a success rate of 93.5% and 98.8%, respectively. Further improvements of the algorithm to enable higher scores in arbitrary visual environments are discussed.