Automated Asparagus Harvester Feasibility Study

• Main Author: Lewis, Andrew Geoffrey
• Language: en
• Published: University of Canterbury. Engineering Management 2013
• Subjects: asparagus; feasibility; project management; automation; image processing
• Online Access: http://hdl.handle.net/10092/7442

The Tendertips Company (TTC) is an asparagus growing a packing business which has a problem. Not enough New Zealanders are willing to manually harvest asparagus. Samoan workers are being employed through the recognised seasonal employer (RSE) scheme which incurs a large cost to TTC. This scheme is also susceptible to a change in government policy at any time. Automated asparagus harvesters have been designed in the past however they inflict too much damage to asparagus plants and the paddocks in which they grow. Several research projects have also been undertaken to minimise this damage while robotically harvesting asparagus however no solutions currently exist. In this project a low-cost system was designed and constructed to determine the feasibility of selectively harvesting asparagus without inflicting damage to asparagus plants or the paddock. The most technical component in this system was identified, accurately identifying and locating asparagus spears to be harvested. A camera and lighting system, along with an asparagus data logging system was designed and tested, with the assumption that if this system succeeded, the development of an automated asparagus harvester would have a very high chance of success. The system proved that individual asparagus spears can be located accurately enough so as not to inflict damage on other spears during the harvesting process: • 96.8% of asparagus spears were located. • Average location error of 3.0mm. The measurement of the size and height of asparagus spears was not very accurate due to the lighting system, however this is expected to be fixed with a design change. A global positioning system (GPS) successfully saved the calculated size of the asparagus spear with its global location to allow for analysis of the asparagus paddocks using the Google Earth application. The cost of robotically harvesting asparagus is forecast to be much less than manual harvesting: • Manual harvesting cost $1.40 per kilogram • Forecast robotic harvesting cost $0.41 per kilogram. If one other investor was obtained to create a new business, which developed an automated asparagus harvester before harvesting asparagus in New Zealand and California, the forecast financials are: • Net present value (NPV) of $1.613 million after ten years. • Internal rate of return (IRR) of 33% after ten years. • Maximum accumulated investment from TTC of $449,000 four years after development first begins. The forecast income is through harvesting asparagus only as selling the machines or leasing the intellectual property is not viable. A guiding document was created to guide TTC with the development of an automated asparagus harvester if it aligns with their business model. The development of an automated harvester: • Is technically viable. • Will lower harvesting costs. • Will ensure all of TTC’s asparagus is harvested when required. • Will return sustainable profits to the child business that TTC should create. The project management techniques adopted in this project ensured the project was completed on the planned day of completion, while remaining on budget: • Budgeted cost of work scheduled $24,478.21 • Budgeted cost of work performed $24,027.54