一种典型DDS锻造操作机运动学分析

锻造操作机的运动学分析是实现操作机运动控制的基础,鉴于大部分学者仅对典型DANGO&DIENENTHAL(DDS)锻造操作机的主运动机构进行运动学分析,对一种典型DDS锻造操作机的整体机构进行运动学分析。该整体机构是由一个平行四杆机构和一个并联机构组成的串并联形式的混联机构。采用修正的Grübler-Kutzbach公式计算其中并联机构的自由度,计算结果表明并联机构的自由度数多于其主动输入数,所以该并联机构的运动无法直接确定。究其原因是机构中4S闭环的侧摆运动规律不唯一,因此对4S闭环的侧摆运动进行优化分析,利用旋转相似变换得到4S闭环侧摆后其输出件的姿态可用yzy欧拉角描述,从而确定该并联机构的运动。采用yzyy欧拉角描述钳杆的姿态,使得前三个姿态角恰好为4S闭环发生侧摆后其输出件的姿态角,从而很容易地建立该操作机整体机构主动输入与钳杆位姿之间的位置关系。在此基础上对该操作机整体机构进行速度分析,并用ADAMS软件对位置分析和速度分析进行仿真验证。

Kinematic Analysis of a Typical DDS Forging Manipulator

Kinematic analysis of forging manipulator is the basis for motion control of the forging manipulator.As most scolars only analyzed kinematics of the main-motion mechanism of the typical DANGO & DIENENTHAL(DDS) forging manipulators,kinematic analysis of the whole mechanism of a typical DDS forging manipulator is carried out.The whole mechanism is a hybrid serial-parallel mechanism,composed of a parallel four-bar mechanism and a parallel mechanism.The degree of freedom of the parallel mechanism is calculated by using the modified Grübler-Kutzbach criterion,the result shows that the parallel mechanism’s degree of freedom is greater than the number of the active inputs,so the motion of the parallel mechanism can not be determined directly.The reason is that the yawing motion law of the 4S closed-loop within the mechanism is not unique,so optimization analysis of the 4S closed-loop is performed.Using rotation similarity transformation,the orientation of the output link of 4S closed-loop after the yawing motion can be described by yzy Euler angle,and the motion of the parallel mechanism is thus determined.yzyy Euler angle is used to describe the orientation of the gripper carrier,resulting in that the first three angles just describe the orientation of the output link of 4S closed-loop after the yawing motion,the relation between the active inputs and the pose of the gripper carrier is then established easily.Velocity analysis of the whole mechanism is also constructed based on the position equations,and the mechanism is simulated by ADAMS software to testify the correctness of the position and velocity analysis.