摘要
农业机器人通常采用履带式或轮式机构作为下肢运动单元,这类农业机器人实现跨越障碍的能力较弱。为了克服这类农业机器人存在的缺点,扩大农业机器人的应用范围,本文提出一种基于3分支6自由度腿部运动单元作为农业机器人的下肢运动单元。该腿部运动单元采用3-UPS机构作为原型,它与履带式、轮式的下肢运动单元相比,具有良好越障能力;对腿部运动单元进行运动学性能分析和结构参数设计,首先推导腿部运动单元的运动学传递方程,利用范数理论定义了腿部运动单元的运动学性能评价指标,分析了运动学性能评价指标的分布情况,采用空间模型理论对腿部运动单元进行了结构参数设计,应用基于全域性能图谱的蒙特卡罗的参数优选方法选取了结构参数。分析结果表明:农业机器人腿部运动单元的运动传递性能指标呈对称分布,腿部运动单元结构参数设计的范围为:上平台半径为120～130mm,下平台半径为40～50mm,上下平台初始姿态的高度为650～700mm,根据优化的结构参数,设计了腿部运动单元的虚拟样机,为农业机器人下肢运动单元的研究提供了理论基础。
The agricultural robot usually adopts caterpillar or wheel mechamsm as lower limbs kinematical unit, the agricultural robot has disadvantage of poor across obstacles. In order to overcome this disadvantage and expand the application range of agricultural robot, this paper proposed a novel leg kinematical unit which has three branches of 6-DOF. The leg kinematical unit use 3-UPS parallel mechanism as the prototype, it has good advantage of good across ob stacles comparing with caterpillar and wheel mechanisms. The kinematics performance of legkinematical unit was analyzed and the structure parameters were designed. First, the kinemat ics transmission equation of leg kinematical unit was established, and the kinematics perform- ance evaluation indexes were defined using the norm theory, and kinematics characteristics were analyzed. Then, using space model theory, the structure parameters of leg kinematical u nit were designed, and the optimal structural parameters are given using the Monte Carlo pa rameters selecting method based on global performances atlas,. Analysis results show that ki- nematics transfer performance indexes display the symmetric distribution of the agriculture leg kinematical unit, upper platform radius is 120 to130 mm, lower platform radius is 40 to 50 mm, and the height of the upper platform and lower platform initial posture is 650 to 700mm. Finally, using a set of optimal structural size parameters, the virtual prototype of leg kinemat ical unit was designed which provides theory basis for the researeh of agricultural robot lower limbs kinematical unit.
出处
《河北农业大学学报》
CAS
CSCD
北大核心
2012年第5期118-122,128,共6页
Journal of Hebei Agricultural University
基金
机械系统与振动国家重点实验室开放课题基金资助项目(NO.MSV-2010-24)
关键词
农业机器人
运动学分析
腿部运动单元
agricultural robots l kinematical analysis l leg kinematical unit
