农业工程学报2017，Vol.33Issue(10)：49-58,10.DOI:10.11975/j.issn.1002-6819.2017.10.007
基于改进PSO的模糊PID高枝修剪机械臂末端抑振算法与试验
Experiment and vibration suppression algorithm for high-branch pruning manipulator based on fuzzy PID with improved PSO
摘要
Abstract
Pruning trees is an important work in forestry production, which plays an important role on the growth of trees and timber and the forest fire prevention. However, domestic and foreign high-altitude pruning machinery is still in its infancy, whose working height is generally less than 8 m and is not high flexible. It is difficult to effectively improve work efficiency in pruning high branches. In this paper, a simple, low-cost mobile tall tree pruning machine was designed, which could be easily towed to the forest area, and prune high branches within 15 m height. This machine had the working radius of 6 m and the maximum pruning diameter of 10 cm. However, in the process of sawing and positioning, due to the long arm span and high load weight ratio, there were obviously flexible features for its arms, and the end-effector (pruning saw) was easy to vibrate during its positioning. Thus, it was difficult to achieve fast and accurate positioning, as well as fix the branch to be cut. Aiming to the above problems, this paper analyzed the flexible characteristics of the boom system with the boom display and the high load weight ratio. On this basis, the vibration suppression control method of the end of pruning saws was investigated to achieve the rapid and accurate positioning of the end of pruning saws. In this paper, focusing the flexible characteristics of the manipulator and the vibration suppression of the end-point, based on the introduction of the boom structure and working principle, we analyzed the impact of flexible features on the positioning of the end of pruning saws by geometric derivation, and the FEM (finite element modeling) was used for the dynamics analysis of the boom system. And the fuzzy PID (proportion, integral, derivative) controller was designed based on an improved PSO (particle swarm optimization) algorithm, in order to realize the active vibration suppression control of the end of the actuator. In the designed fuzzy PID controller, the improved PSO algorithm was used on the numerical simulation model to optimize the fuzzy domain intelligently. The parameters of the PID controller were adjusted and the vibration of the pendulum saw was suppressed, and the simulation and experimental verification were performed in the SIMULINK environment and a prototype system, respectively. The experimental results showed that the design of the tall trees pruning manipulator control method could realize the end-point vibration suppression, and the pruning saw could be accurately positioned into the steady state during the localization process in a short period of time. The actual measured data showed that the overshoot was less than 50% under the open-loop state, the amplitude decay was less than 5% of the peak after 1 s, the vibration adjustment time was less than 1 s, and the system could achieve steady state, and achieve a more effective vibration suppression effect. Verification results showed that under the effect of the control algorithm and the controller designed in this paper, the end-effector could be stabilized in a short time after the positioning to achieve better active vibration suppression effect. The control algorithm improved the pruning saw's positioning accuracy and speed, and optimized the dynamic performance of the entire machinery to ensure the flexible control of high branch pruning machinery. Through the simulation analysis and prototype test using the proposed active control algorithm, the results verify the reliability of the algorithm and accumulate the valuable experience for the further development of the high branch pruning machinery.关键词
机械臂/林业/振动控制/振动抑制/柔性特征/改进粒子群/模糊PIDKey words
manipulators/forestery/vibration control/vibration suppression/flexible Features/improved PSO/fuzzy PID分类
农业科技引用本文复制引用
李扬,侯加林,苑进,赵新学,刘雪美,张丽..基于改进PSO的模糊PID高枝修剪机械臂末端抑振算法与试验[J].农业工程学报,2017,33(10):49-58,10.基金项目
国家自然科学基金项目(51675317、51475278) （51675317、51475278）
"十二五"国家科技支撑计划资助项目(2014BAD08B01-2) （2014BAD08B01-2）
山东科技发展计划项目(2013GNC11203、2014GNC112010) （2013GNC11203、2014GNC112010）
山东省农机装备研发创新计划项目(2015YB201) （2015YB201）
