Research On 6-DOF Robot Arm Trajectory Planning Based On Given Key Points

The robot has high efficiency,repeated mechanical action and the ability to work in harsh environments,and is widely used in economic life and industrial production.The trajectory planning design is an important part of the robot's execution action,which determines the robot positioning and precision operation efficiency.The traditional trajectory planning method makes it difficult for industrial robots to have too long loading time and inaccurate loading position due to mechanical arm vibration during loading.In this thesis,the 6-DOF manipulator loading process is taken as the research object,based on the given key points(the key points are selected by multiple teaching methods),the mechanical arm structure model construction,the trajectory planning positive and negative solutions,and the trajectory are studied.Interpolation method,time optimal trajectory planning.Through this research,the feeding time is shortened,and the dynamic parameters are used as optimization constraints to reduce the impact of shock and vibration to ensure the accuracy of loading.The contributions and innovations of this paper are mainly reflected in the following aspects:(1)The mechanical arm structure model is built.This paper studies and analyzes the DH parameter method,taking the rotation angle of the previous link as the description of the rotation angle of the next link,and combining the length of the next rod to determine the next adjacent by the two values.The pose state of the rod,and then analogy to complete the parametric model construction of the entire robot arm.(2)The trajectory planning is positive and negative.In this paper,by analyzing the current mainstream three positive and negative solutions,this paper proposes an improved numerical calculation method suitable for this study,and establishes the algorithm studied in this paper.After inputting the initial value,the positive solution of the end pose and the end pose are obtained.The inverse solution of the joint,and then the calculated inverse solution is automatically connected with the program of the next trajectory planning.Compared with the traditional calculation method,the time cost is shortened to 0.1s,and the calculation error is controlled within 0.5%.(3)Track interpolation method.In this paper,the Cartesian spatial interpolation method and the joint rotation angle interpolation method are analyzed.Based on the joint position interpolation method,the 5-7-5 piecewise polynomial interpolation function suitable for this study is proposed for mathematical modeling.The advantage of using the piecewise function as an interpolation function is that it not only preserves the computational simplicity of the low-order function,but also obtains the feature that the high-order function is easy to optimize,making the planned trajectory smoother and more convenient to control.(4)Time optimal trajectory planning.In the previous research process,we found that the planned trajectory can meet the needs of the work,but it can be further optimized to reduce energy waste while meeting the mechanical properties(vibration and shock).After analysis and comparison,the composite shape method is selected in the end.This method has the advantages of fast iteration and accurate constraint calculation for the model with fewer constraints.In this paper,the trajectory planning function planned in the previous paragraphs is based on kinematic parameters.As a constraint,the angle,rotation speed,rotational acceleration,etc.are introduced into the composite method for experimental analysis.The final time is optimized by about 16% with respect to the initial value,which improves the production efficiency and responds to the call of the green industry.In this study,industrial robots are used to grasp raw materials as experimental analysis conditions to discuss trajectory planning problems.After the mechanical arm has been taught to determine the key points,the robot arm trajectory can be quickly and efficiently planned,the running time is reduced and the planned trajectory handling performance is better;at the same time,the inverse solution value can be quickly calculated,to a certain extent.Lay the research foundation for avoiding obstacles and other issues.