Optimum Design and Trafficability Analysis for an Articulated Wheel-Legged Forestry Chassis

Abstract High trafficability and stability are the most two significant features of the forestry chassis. In this study, in order to improve surface trafficability, a novel articulated wheel-legged forestry chassis (AWLFC) is presented. To balance the trafficability and stability, a serial suspension system which is a combination with the active four-bar linkage articulated suspension (AFLAS) and passive V shape rocker-bogie is proposed. Then, parameter optimization with a comprehensive object function is implemented not only to enhance the trafficability and stability benefit of the structure but also to reduce the wheel slip. After that, through the flexible kinematic model based on screw theory, characteristics such as leveling ability and surface profile accessibility of the chassis are analyzed. The minimum accessible radius is obtained as 3088 mm, and the longitudinal and lateral leveling angle reaches to 22 deg and 28.7 deg separately. The new chassis performs better on leveling ability and surface profile accessibility than the forestry chassis in the current literature. Finally, through the results of simulation and prototype experiment, error rates related to the flexible analysis are reduced by 12.2% and 8.6% compared with the rigid model. Previously inaccessible forestry working environments can be available with the development of AWLFC.