Date of this Version
A procedure is presented for determining the performance of three-point mounted implement guidance systems. A test track with tractor ramp, implement ramp, sine wave, and curve path shapes was used as the desired path to guide the tractor and implement, and as a reference location for measuring implement positional errors. Potentiometers were used with mechanical frames to measure the tractor and implement positional errors (lateral displacement between the intended and actual travel paths). An optoelectronic sensor triggered acquisition of data from all sensors at known locations [15.2 cm (6 in.) intervals] along the track. The accumulated errors for the tractor and implement positional error transducers included components of calibration, orientation angle, and wobble. The estimated accumulated errors for the tractor positional error transducer and implement positional error transducer were 0.91 cm (0.36 in.) and 0.99 cm (0.39 in.), respectively. The percentages of implement positional errors within an acceptable error band provide more relevant information for producers in row-crop agricultural situations than means, ranges and standard deviations. Tests were conducted with an articulated implement guidance system on fields with 0% side slope and fields with 5% side slopes at travel speeds of 4.8 and 8.0 km/h (3 and 5 mph). The tractor guidance system kept at least 70% of the tractor positional errors within a ±3 cm (±1.2 in.) error band except on the curve on the field with 0% side slope at 4.8 km/h (3.0 mph). When the error band was widened to ±5 cm (±2 in.), the tractor guidance system controller kept 94% of the tractor positional errors within the allowable error band on the curve on the field with 0% side slope at 4.8 km/h, and 100% of the tractor positional errors within the allowable error band for all other test combinations.