Performance tests of three-point mounted implement guidance systems: II. Results

Side-shift and disk-steer implement guidance systems were tested for differences in performance during cultivation on fields with 0 and 5% side slope. Test speeds were slow (4.8 km/h, 3 km/h) and medium (8.0 km/h, 5 mph). Test path shapes included a tractor ramp, implement ramp, sine and curve. Performance measures included tractor positional error, implement positional error, torque from side forces on the cultivator non-swiveling coulter, and travel speed Relatively few significant differences between guidance systems were detected, and most of those involved interaction with path shape. Therefore, no clear conclusion could be reached indicating one guidance system was better than the other. There were no differences between the effects of the two travel speeds on the performance measures directly related to the implement guidance (implement positional error and the torque on either coulter) indicating that for future experiments only one of the travel speeds need be included. The implement positional error distributions indicated the side-shift system kept a higher percentage of errors within the +/-3 cm (+/-1.2 in.) and +/-5 cm (+/-2.0 in.) acceptable error bands in the test situations where the rows were mostly straight (tractor ramp, implement ramp and sine path shapes), while the disk-steer system performed better with the +/-3 cm (+/-1.2 in,) acceptable error band in the rest situations were the rows were mostly curved. Both implement guidance systems performed well in keeping the implement centered between the crop rows as at least 80% of the implement positional errors were within the +/-5 cm (+/-2.0 in) acceptable error band. The torque from side forces on the non-swiveling, residue-cutting coulters of the side-shift system were less than or equal to, not greater than the torque for the disk-steer system.