Portal Crane Luffing Mechanism Of Four-bar Linkage Optimization Design

The portal crane is a kind of representative rotary rail crane, which is also thefirst developed crane type in our country. And the design of luffer is an importantconstituent content during the structure design of portal crane. Its design qualitywill directly affect the economy, reliability and serviceability of the whole device. The paper studies four-bar linkage luffer of portal crane. By taking levelluffing as primary optimization object, thus the load could be moved along a levelline to save the driving power, a mathematical model of the luffer is established.Further more, some effective measures such as reducing the dimension of thedesign variable, returning to the last search spot when the variables overpass itsboundary, have be taken to against the frequently arising problem of overpassboundary during the solving of inverse trigonometric function. An improved genetic algorithm is provided to solve the mathematical modelmentioned above, which has a better performance than the classical methods toavoid trapping in locally optimal solution. A reliable CAD program of optimized design is also developed and a conciseand friendly interface is offered to the designer. Finally, the operating methods ofthe software are presented by the discussion of a practice example, which verifiesthe use value of the software, too.