Method and apparatus for determining collision courses

Claim 1

IN COMBINATION, A MOVING VEHICLE, AND CONTROL MEANS ON SAID VEHICLE ADAPTED TO DETERMINE WHEN SAID VEHICLE IS ON A COLLISION COURSE WITH AN INTERFERING OBJECT, SAID CONTROL MEANS COMPRISING FIRST MEANS FOR MEASURING THE TANGENTIAL COMPONENT OF RELATIVE VELOCITY BETWEEN SAID VEHICLE AND OBJECT, SAID FIRST MEANS BEING OPERATIVE TO PRODUCE A FIRST CONTROL SIGNAL WHEN SAID TANGENTIAL COMPONENT HAS A MAGNITUDE BELOW A PREDETERMINED LIMIT INDICATIVE OF THE LINE-OF-SIGHT BETWEEN SAID VEHICLE AND OBJECT REMAINING SUBSTANTIALLY PARALLEL TO ITSELF AS THERELATIVE MOTION BETWEEN SAID VEHICLE AND OBJECT PROGRESSES, SECOND MEANS FOR MEASURING THE RADIAL COMPONENT OF RELATIVE VELOCITY BETWEEN SAID VEHICLE AND OBJECT, SAID SECOND MEANS BEING OPERATIVE TO PRODUCE A SECOND CONTROL SIGNAL WHEN SAID RADIAL COMPONENT HAS A SENSE INDICATIVE OF SAID VEHICLE AND OBJECT APPROACHING ONE ANOTHER AS SAID RELATIVE MOTION PROGRESSES, AND THIRD MEANS RESPONSIVE TO THE SIMULTANEOUS PRESENCE OF SAID FIRST AND SECOND CONTROL SIGNALS FOR INDICATING THE PRESENCE OF A COLLISION COURSE BETWEEN SAID VEHICLE AND OBJECT.