Hybrid drive parallel arm for heavy material handling

A new hybrid cylinder/wire drive parallel arm (simply called 'a hybrid arm') for manipulating heavy materials in construction and ship building works is proposed. Various hybrid arms with different combination of cylinders and wires are compared with the conventional Stewart platform and a multi wire drive mechanism. Their workspaces considering orientation are evaluated. The most suitable hybrid arm for heavy material handling is the mechanism with three cylinders, four wires, and one connecting rod between the cylinders and the end plate. This hybrid arm is modified into a mechanism with a variable length rod for the application of manipulating a precasting concrete board with a size of 3 × 6 × 0.2<m] and a weight of 10<t], which is used in automatic building construction systems; a prototype of this arm has been designed and developed.