Design Of Six Wheeled Leg-Swing Chassis For Forestry Equipment And Its Obstacle Performance

Chassis,which is the key component of forestry equipment,directly determined whether it could work in the forest or not.The development of this is shifting from the traditional model to the new generation.The dissertation was supported by the Fundamental Research Funds for the Central Universities-Special Forestry Equipment(TD2013-4).The work is based on the real site conditions in China,such as,there are many small obstacles and gully.A Six Wheeled leg-Swing Chassis of Forestry Equipment,which has a strong performance in obstacle-surmounting and terrain adaptability,is presented in this paper.The main research works were listed as follows:1.The development of Six Wheeled leg-Swing Chassis of Forestry Equipment.By studying about the Structural features and functions of engineering machinery and Forestry Equipment,with the processes on the Demonstration of key components,design and optimization about structure and spare parts,Validation about the drawing,the prototype machine was assembled.2.A kinematics model about Six Wheeled leg-Swing Chassis of Forestry Equipment was established with the D-H method.Maximum vertical obstacle clearance height was calculated with Positive and inverse solutions based on D-H method.According to the assembly error of each joint,Vertical obstacle height deviation and the speed ratio of each joint were studied based on Robot Differential Transformation and Jacobian matrix.Through the ADAMS simulation and prototype experiment,the Kinematic model was tested and verified.3.The Key structural parameters,optimal location of dual putter on the front wheeled leg and its Pressure ratio were analyzed in this paragraph.By establishing the Mathematical relational model between the optimal layout of Double push rod and Maximum obstacle clearance height,the optimal ratios were generated,which will be regard as the Theoretical basis to improve the Obstacle performance.4.Based on the kinematics model,chassis simulation was done in the virtual roaming environment of OSG software,by implementing the chassis wheel-legged movement and the structure of the whole terrain interaction to verify the obstacle-surmounting performance.Verify the correctness of the algorithm for relationship between chassis posture angle and change of the terrain height,which provides a theoretical basis for the future large-scale development and application of intelligent forestry mechanical chassis.In this paper,the design of six swing arm type wheel-legged chassis prototype can completely work according to the requirement of design,its wheel-legs can reach the biggest vertical obstacle height of more than 400 mm,which accords with theoretical calculation.By OSG virtual roaming environment simulation,the validity of the designed chassis kinematics model was demonstrated,the chassis is entirely suitable for application in the field of forestry atypical unknown terrain.The research provides theory basis for solving this problem of our country forestry equipment chassis' barrier performance requirements.