Design of a wrist and operator interface for an agricultural manipulator : a thesis presented in partial fulfilment of the requirements for the degree of Master of Technology in Engineering and Automation at Massey University
Roadside mowing and tree pruning has always been a job that most people would consider as unpleasant. This project is concerned with the development of a system to make these tasks simpler, safer and more pleasant for the operator. 1.1 Software This project is involved with the design of a complex mechanical system, which could be done using a modern CAD package. To achieve this, research into what modelling package was best was necessary. Several contenders were considered. These include SolidWorks , Mechanical Desktop  and CADKEY . CADKHY was disregarded early as it is not as expandable as the other two. Both SolidWorks and Mechanical Desktop have additional software packages that allow for motion, force and stress analysis. The major difference between SolidWorks and Mechanical Desktop, is that SolidWorks is a true three dimensional modelling package, whereas Mechanical Desktop is based on the two dimensional AutoCAD system with a three dimensional toolbox. The choice was finalised to SolidWorks as it handles three dimensional modelling more efficiently. Massey University also uses SolidWorks. This allowed the project to continue while studying at the Turitea campus. 1.2 Overview This project is involved with the development of a wrist mechanism and hydraulic control system for an agricultural manipulator. The manipulator is called the Hydra Trim and was developed by Pivot Engineering Ltd. Napier . The wrist mechanism is an integral part of making the Hydra Trim a success. The hydraulic control requires not only the valves but also an interface between the operator and the valves.