| Landscape trimming is an important part of landscape engineering in modern city.With the improvement of automation level today,the level of automatic garden trimming equipment still needs to be improved although this kind of equipment has been developing.Therefore,this paper researches and designs a new automatic garden trimming manipulator which can topiary,and achieving orientating the hedge trimming position based on image recognition methods.In this paper,adopt the structural scheme of joint coordinate manipulator according to the performance requirement of garden trimming manipulator,and then designing virtual prototype of manipulator with Pro/E software.The paper analyzed three typical different operating conditions,the key parts of the garden trimming manipulator such as base,big arm and middle arm were analyzed by finite element method.The mechanical properties of these key components are guaranteed under various working conditions.Static analysis and fatigue analysis are carried out on the main shaft of cutting tools to ensure the service life of the main shaft of cutting tools.In order to prevent the machine from resonance under the influence of the external environment,modal analysis is carried out on the pruning manipulator to obtain the natural frequency and vibration mode of the manipulator,so as to ensure the machine can work smoothly.Making the kinematics analysis of the garden trimming manipulator by algebraic method to solve the forward and inverse kinematics of this manipulator,and the trajectory planning of the hemispheric helix.The working space is analyzed by using the Monte Carlo method.The dynamic model of the pruner is established to determine the relationship between the speed and the force in each joint of the manipulator based on the Lagrange method which provides theoretical basis for dynamic analysis.Combined with ADAMS to achieve the kinematics and dynamics simulation of virtual prototype.The driving force of each joint of the trimming machine is obtained under normal operation condition which provides a basis for the selection of the driving part.Studying to determine the scheme of image acquisition of hedge,and designing a scheme for the obtained hedge image.Defects in depth images obtained by the Kinect,designing the restoration algorithm of depth image.Combining the geometric features of the hedge image and the distance information of the depth image,determining the position characteristics of the pruning center point of the hedge.In order to further improve the speed and stability of mid-movement,RBF neural network algorithm was adopted to solve the inverse kinematics of the garden pruning manipulator to improve the d-h method to solve the complex and slow solving process of inverse kinematics,and then the optimized s-curve was used for speed control.Selecting parts,processing and assembling physical prototype.Researching and developing the automatic garden trimming manipulator control system which includes the software and hardware design.After completing the above work,carry out spot test of experimental prototype,hedge trimming test and alignment test,the experimental results all meet the expected requirements,and also experiment on hemispheric moulding of hedge.The above works provide theoretical and experimental basis for the subsequent related products research and development. |
