Multiple Degrees Of Freedo M Mechanical Arm Kinematics And Dyna Mics Research In Vehicle

Multifunctional truck that this paper refers to aims to finish some work every once in a while in urban road of both sides, such as trimming hedges, spraying pesticide, pruning branches, digging holes on the side of the road, etc. Multiple degrees of freedom mechanical arm in the end of multifunctional truck can realize the function of lifting, rotation, pitching scaling, Designing a unified platform for the quick change at the end of the multi degree of freedom mechanical arm can quickly change various devices and complete all kinds of the corresponding work, which achieves a variety of purposes of a car, greatly reduces the number of the truck of a single function, saves the cost of the equipment and management and improves the working efficiency.The tasks of multifunctional truck have big differences. Multi degree of freedom mechanical arm in the end has different posture because of different working conditions, such arms bent, horizontal scaling vertical rise, frequent turning, etc, which causes complex motion state and makes some status in dangerous conditions of overturning easily. The devices in the end have larger weight and can produce larger and more complex load during working, which leads to making the vehicle and local institutions in big alternating load condition, and complex and serious stress condition.This paper introduces the utility vehicle and makes kinematics and dynamics analysis about multiple degrees of freedom mechanical arm in the rear. The following analysis and research work is main content of the paper:(1) Introduction of the overall structure and analysis of working condition.The paper analyzes the main structure and working principle of mechanical arm that can realize these functions of lifting, rotation, pitching, scaling. The paper also makes the mechanical arm having smaller size, better stability and reliability under the premise of satisfying the requirement of stiffness and strength. The end of the mechanical arm installs the device of keeping level and quick change device, which is the key of achieving the various functions of the truck; This article also made a more in-depth analysis about these.(2) Three-dimensional modeling and simulation and overturning resistance analysisThe article introduces the modeling process of mechanical arm. Using the simulation software ADAMS conducts dynamics simulation, which can obtain the curve of displacement, velocity, acceleration, and the corresponding angular velocity angular acceleration about the execute device. The article also makes overturning resistance analysis to the truck to verify the stability of under bad conditions.(3) Kinematics analysisKinematics analysis includes positive and inverse kinematics analysis. By establishing the kinematics equation, we can obtain relations of displacement, velocity and acceleration about mechanical arm to make the position of the mechanical arm to reasonable requirements.(4) Dynamics analysisDynamics studies relations between movement and stress about mechanical arm, which plays an important role in the simulation research, dynamic property and optimum index. Using finite element analysis software ANSYS studies strength and stiffness of mechanical arm, which can obtain the maximum strain value, the maximum stress value of dangerous parts, and also makes modal analysis. These can reach the requirements of stability and safety of mechanical arm.