Abstract: A detection system for use in a movable large haulage vehicle operating in a controlled ground environment to prevent collision with other objects in the environment wherein such objects each have a source for omnidirectionally radiating an optical pulsed signal having a selected pulse repetition rate which identifies the object. The vehicle uses detectors mounted at selected locations on the vehicle, which detectors respond to pulsed signals from objects in close proximity to the vehicle. Appropriate circuitry is used to detect the presence of the objects, the ground direction of the objects relative to the vehicle, and the type of objects so detected.