In certain aspects, this invention is a "control system" that detects and minimizes (or otherwise optimizes) an angle between vehicle centerline (or other reference axis) and vehicle velocity vector--as for JDAM penetration. Preferably detection is exclusively by optical flow (which herein encompasses sonic and other imaging), without data influence by navigation. In other aspects, the invention is a "guidance system", with optical-flow subsystem to detect an angle between the vehicle velocity vector and line of sight to a destination--either a desired or an undesired destination. Here, vehicle trajectory is adjusted in response to detected angle, for optimum angle, e.g. to either home in on a desired destination or avoid an undesired destination (or rendezvous), and follow a path that's ideal for the particular mission--preferably by controlling an autopilot or applying information from navigation. Purposes include real-time angle optimization to improve autopilots or guidance, and vehicle development or testing.