This paper describes the working of three basic types of pre-crash sensor system: radar, video and infra-red (IR) or lidar. Radar is usually a single beam system operating on a pulse sent and received. More powerful systems use three to five beams behind a projecting lens. Video systems need additional illumination: systems available employ object identification to give position and distance using one or two receivers. IR systems use a short light pulse which is reflected from the object, in a single- or multi- channel system. Examples of sensor systems are given. Future applications of pre-crash sensors could be in airbag deployment only at certain speeds with a trigger delay, and in the use of safety actuators to avoid the collision. For the covering abstract see ITRD E126782.
Abstract