Design of Ground Surface Sensing Using RADAR
Ground sensing is the key task in harvesting head control system. Real time sensing of field topography under vegetation canopy is very challenging task in wild blueberry cropping system. This paper presents the design of an ultra-wide band RADAR sensing, scanning device to recognize the soil surface level under the canopy structure. Requirements for software and hardware were considered to determine the usability of the ultra-wide band RADAR system.An automated head elevation sensing system is developed and tested in wild blueberry fields. The developed system consisted of ultra wide band RADAR system customized to cover the width of the harvester head, a real-time kinematics global positioning system (RTK-GPS), custom built software for analyzing the electromagnetic waves, and a single board computer. The custom software acquired and processed the RADAR sensing data in real-time by using Fast Fourier Transform technique. Two wild blueberry fields were selected in central Nova Scotia to evaluate the performance of the developed system. One-hundred four experimental plots were randomly constructed within two fields and ground level were recorded manually and compared with RADAR sensed data to evaluate the accuracy of the developed system. Results of regression and scatter plots revealed that the proposed system was able to sense the ground level in real-time. The test results showed the potential of applying such system on working harvesters.