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.