| Broccoli harvesting has been a labor-intensive process requiring workers in the field to do considerable bending and stooping as they cut mature broccoli heads from the plants. Developing an operational mechanical broccoli harvester would eliminate the need for workers on the ground and the associated bending and stooping. To be functional, this system should have a potential harvest rate greater than 0.4 ha/da (1 ac/da).;Three broccoli harvester prototypes were developed and tested, the second and third prototypes were improvements on the previous units. Through prototype iterations, a working single-pass harvester has been developed and field-tested. The third harvester prototype was tested at various ground speeds. The harvester achieved harvest rates to 2.2 ha/da (5.4 ac/da) assuming a ground speed of 4.0 km/hr (2.0 mph), a row spacing of 0.9 m (3 ft), and 6 hours of harvester operation per day. Major damage to the heads and florets did not occur.;Once a functional mechanical broccoli harvester was developed, consideration was given to optimizing the hydraulic systems of the harvester to obtain the best selection of hydraulic components to minimize hydraulic system power requirements.;Equations were developed from node-to-node analysis of the hydraulic schematic diagram of the system. Two steady-state mathematical techniques were used. The first was to solve the system of equations for specific unknown quantities in the system. The other was to use nonlinear optimization of the system. This allowed the analysis of "what-if" applications. The nonlinear optimization analysis indicated power savings to 43% could be achieved by resizing hydraulic components.;In conclusion, both mathematical models indicate there are opportunities to improve the hydraulic system of the harvester. |
