Structural Synthesis And Automatic Kinematics Analysis Of Face-shovel Digging Device

With an increase of open-pit mining requirements, the large-scale face-shovelhydraulic excavators have been applied more and more widely. However, at present thereexist only two kinds of structures for the face-shovel digging device and only one can beused domestic products because of the monopoly of abroad intellectual property. In viewof that,15kinds of new structures of face-shovel excavators are synthesized in this paperand also, the automatic kinematics analysis of the corresponding structures are achieved.Inspired by America Terex Corporation presented Triple-Power type digging&loading device, which has12-link and3degrees of freedom (3DOF), planarsimple-jointed topological graphs with12-link and3DOF are synthesized on basis oftopological graph atlas database of kinematic chains. Finally15kinds of new structuresfor face-shovel excavating appliances are refined in this paper by developing andcomplying “322selection principle”,“kinematic chains transformation principle” and“face-shovel digging device optimization principle”.In order for further analyzing of performance for those mechanisms, the first step isto accomplish their kinematics analysis. Aiming at the features of Multi-loop CouplingMechanism, an analysis approach called “minimum kinematics unit” is presented. Themain procedures of the above-mentioned analysis approach are demonstrated as follows:Firstly, the face-shovel digging device is split into minimum kinematics units andkinematic analysis is conducted, then programmed as subprogram module; Secondly,block diagrams of kinematics analysis are built according to the geometrical relationsbetween loops, which not only reflect the minimum unit needed by kinematic analysis ofits corresponding mechanism but the input and output transmission relations of each unit;Finally based on those relations main program for kinematics analysis of the wholemechanism is compiled and thus, automatic analysis for kinematic is realized.Software of automatic kinematic analysis for face-shovel digging devices areprogrammed based on MATLAB programming language, by which the forward positionsolutions, inverse position solutions, workspace, velocity analysis and Jacobian matrixes of the15varieties are able to be automatically presented.