Make ground strikes a thing of the past
Ulf Thorstensson Product Development Manager for HARDI Australia was given a brief to investigate and provide HARDI with a boom AutoHeight control solution.
Suspension dampened outrigger wheels have kept wide booms at a constant height and parallel to the ground or from striking the ground in undulating and rough conditions. These outrigger wheels have saved many booms from destruction but they have their limitations. Wheels add weight and when they make ground contact extra forces that can cause fatigue and damage are transferred through the boom.
Although a number of off the shelf systems were available, understanding the dynamics of in-field boom behavior and the ultrasonic height control system capabilities was paramount to the selection process.
‘Being able to fine tune the boom and the electronics was the key to delivering the right solution for HARDI’ said Ulf who doesn’t do things by halves, ‘and I believe thorough testing will always deliver the best result’.
The project team of David Shillabeer and Alan Miller tested three auto boom height control systems at the HARDI test farm north of Adelaide to determine who offered the best available technology. Four different tests were captured on video to examine the system capability for contour following, crop and ground clearance, speed, wing roll and cornering reactions.
‘We chose a Canadian based company, Norac as our future partner in this new boom height control technology, explained Ulf. ‘Their system works on flow based proportional valve control regulation of the tilt cylinders and delivers excellent response times over undulating terrain.’
Working closely with Dean Hockley and James Schnaider from Norac to incorporate the UC4 auto boom height control on a 36m FORCE boom, the HARDI engineering team employed a combination of hands-on experimentation as well as a solid understanding of the theory behind the boom movement characteristics. Ongoing collection of boom movement data and valve activity was used to analyse and adjust the system for optimal performance.
A third sensor controls the centre height
‘Norac’s sensors are designed to identify both crop and ground height as separate targets. The system employs a third sensor on the boom centre to control the centre height off the ground and monitors chassis roll to reduce the effect on the boom by instantly compensating the wing tilt ’ Said David Shillabeer.
The Norac sensors are encased in very solid alloy housings and then mounted on a well built arm. On setup the correct boom model is selected in the software and automatically uses settings tested to be the best for the boom.
‘The Norac initial setup and calibrating process that is done in the HARDI factory is simple and only take 15-20 minutes’. explained Alan Miller, who did most of the test driving. ‘A recalibration by the farmer will only take 5-8 minutes’.