ORACLE - Our First RobotORACLE - Our First RobotExit CSIRO
David Henshaw had redesigned his machine to run longer shearing blows from the backbone to the bottom of the side but for this he needed a much longer track. He also needed a curved track which would allow the cutter to start almost level at the backbone, and then curve over the edge of the rib cage and down the side. The control system was improved too, with more robust electronic sensors under the comb and a more compact arrangement of the electric motors.
Sadly, the new arrangement never met David's expectations. The curvature of the track introduced speed control problems as the motor carriage rounded the corner and then moved off down the straight section. The sensors did not seem to work as well as expected. A special capacitance proximity sensor (p. 50) was designed and built under contract by AWA Pty Ltd, a large electronics firm, but its sensitivity was less than David had hoped. It just never seemed as good as the first machine 18 months before. In CSIRO's final technical report, it was written off with little more than a paragraph and a few comments of which only one had a positive note to it.
As soon as CSIRO had announced their intention to review their own work in October 1978, we were conscious of increasing pressure on us. There was little prospect of shearing with our rig before the review started. By September we were aware of the disappointments at CSIRO. We also knew that CSIRO were evaluating the economic prospects for shearing robots, but we were not at all happy with their analysis. Even though Roy Leslie and I were deep in the technical details of constructing our own machine we were apprehensive about the prospect of CSIRO deciding to withdraw from the project. What would be the reaction of the Corporation if they decided to pull out? We felt we were in a weak position with our own rig still under construction.
CSIRO reviewed all their results - technical and economic - by the middle of October, and their report finally arrived on my desk late in October with a request from the Corporation for my comments. I was immediately dismayed by the tone of the summary and conclusions:
'it is difficult to see a basis for regarding automated shearing as a worthwhile area for investment in the light of present knowledge or expectations'.
With great hope and optimism I finished my reply by predicting that our experimental results would soon be available and it would be premature to assign any great significance to the conclusions of CSIRO's report!
Two weeks later, the Corporation reluctantly accepted CSIRO's withdrawal but asked us to proceed as quickly as possible. It was all too easy for us to have felt undermined by the CSIRO decision to withdraw from the project. In retrospect, it was the right decision, and it left us in charge of our own destiny - an enviable position. We had felt very vulnerable without experimental results. But we were newcomers to wool research, and did not understand the determination of the Corporation to press on.
David Henshaw left CSIRO not long after, and commenced an active political career, representing the dockland areas of Melbourne in the Victorian state parliament.
Re-reading the full CSIRO report 11 years on I found some interesting comments made by David Henshaw in his own conclusions which I missed. I found justification for what I had always supposed were the real reasons for their withdrawal. In David's own words:
'The work described in this report, taken together with the more refined development work undertaken by the team at the University of Western Australia, suggests that automated shearing is technically feasible. However, it is not clear that any practical system would be commercially viable in terms of yielding a return to investors. Indeed, economic analysis, using assumptions which must be considered optimistic rather than pessimistic, indicate that it might well be more expensive than manual shearing. It may be that different approaches for a more refined analysis would lead to a different conclusion. In either case, this division of CSIRO does not have the expertise or resources available in areas such as electronics, digital processing, or hydraulic control to justify participation in the exacting work which would be required in further developments. In this respect it is suggested that the teams at the University of Western Australia and Musheep (Melbourne University Sheep Handling Experimental Establishment located at the University and at Werribee near Geelong and part of the Department of Civil and Agricultural Engineering of Melbourne University) are better situated.'
We inherited three jewels from the CSIRO crown. The first was the existence proof that automatic shearing was possible. Though intangible, it was, and still is, the most important of the three.
The second was resistance sensing for controlling the comb height. It was David's idea, and served us well for ten years of shearing experiments. Yet David himself had already realized that it was not the ultimate answer. It took ten years to find a better answer.
The third was David's design for the cutter, but just a few months later
we were to discover a major flaw. Yet the subsequent investigation of
its failure was to lead to the first real understanding of the physics of
wool cutting.
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September 1997