中文摘要：

为克服传统机械式挖掘机结构庞大复杂且不能完成灵活多变的挖掘动作等不足，以及液压式挖掘机液压元件加工精度要求高、维修保养成本高、容易漏油等缺点，设计了一种新型平面三自由度正铲式可控挖掘机构。它由三个控制电机驱动，可通过编程方便地实现柔性化的运动输出规律，且各零部件加工装配要求不高。为获得这类新型挖掘机构运动学输入输出关系的规律性认识，针对其结构特点，首先运用闭环矢量法建立机构的运动学模型，根据隐函数存在定理，分析了机构处于理论工作空间边界的条件，在此基础上，计算得到了机构的理论可达工作空间，并给出了仿真对比结果。结果表明：在给定尺度参数条件下，这种新型的可控机构式挖掘机挖掘距离为2．5m，举升高度为2m，能满足挖掘、举升、卸载和平整等工作需求。

英文摘要：

To overcome the problems of large structure and less flexible in operation of traditional mechanical excavator, and high demand in part processing, nance of widely used hydraulic excavator, a novel planar 3 type controllable excavating mechanism is proposed, which leakage of oil, and high cost of mainte- degree-of-freedom （DOF） face shovel can achieve flexible output trajectories because it is driven by three controllable motors and transmitted by linkages. To obtain a regularity understanding of the kinematic input-output relationship of this type of excavating mechanism, the kinematic model was established by using closed-loop vector method. The boundary condition of the- oretical workspace was analyzed according to the existence theorem of implicit function, and the at- tainable theoretical workspace was calculated. The simulation and comparison results indicate that： in a given dimensional parameter condition, digging distance of the new multi DOF controllable ex-cavating mechanism is 2.5 m, and the raising height is 2 m, which can satisfy the demands of shov- eling, lifting, dumping and leveling.