Akustisches Radar zur Detektion von Objekten im Heuschwad

During the collecting of hay in agriculture there are often damages on the pick up module of the trailer due to objects (e.g. stones, metal pieces, pieces of wood…) hidden inside the hay swath. Therefore it was asked for a system which should be applied in front of the traction engine to penetrate the hay. This system should then provide a signal to the trailer if any obstacles are detected. We propose an acoustic UWB radar system, because sonic waves from 500 Hz to 5 kHz can penetrate the hay without great losses. To achieve a better resolution in motion and propagation direction, we use chirp pulses which are modulated with m-sequences. Thus a continuous, noise like broadcasting is realised which is hardly disturbed by the tractor engine noise. The analysis and the sending of the signal are both carried out on commercial available audio hardware which is accessed via Linux.