Combining two radar techniques to implement a collision avoidance system

Many microwave collision avoidance radars have been tested using FMCW (frequency modulated continuous wave) radar and pulsed radar working around 10, 35 and 60 GHz. The aim of this paper is to describe an efficient radar system, termed bimodal, obtained by the combination of these two systems. The FMCW sensor is used for close detection and easier speed calculation, and the pulsed one for large distances and multi-target separation. The bimodal system has been used to improve the performances of the two sensors by retaining the advantages of each. The new radar is able to detect obstacles between 2 and 150 m with low emitted power. The whole system is controlled by a decision program unit. An accuracy of +/-1 m has been achieved.