What are the obstacle detection methods?

Answer 1

There are a variety of competing methods that have been proposed for obstacle detection and many papers written on such methods. There have been few papers, however, which have offered more than a trivial comparison of the various methods, especially in any analytical fashion. All systems have their drawbacks, and almost all methods are susceptible to problems caused by environmental conditions such as ambient lighting (or lack thereof) or precipitation. A vehicle-mounted optical flow system is unlikely to be successful for static obstacle detection, but that a stereo system is likely feasible for obstacle detection in daylight. Current laser range-based methods have not been proven at highway distances and are too expensive as a solution for consumer vehicle obstacle detection. Laser intensity has been ignored as a potential solution by most researchers. Radar, while an excellent means of detecting vehicles, is an unlikely candidate for detecting small static obstacles because of their relatively low radar cross section. It is likely that multiple detection methods will be necessary for reliability. For example, the combination of stereo and laser shows promise since stereo works well in daylight, and a laser system works best in little or no ambient light.