根据两转一移并联机构两转动自由度转轴的分布，提出构造五自由度混联机器人机构构型的新思路，基于2-RPU&UPR并联机构构造一种新型五轴混联机器人机构。建立2-RPU&UPR并联机构的位置正反解模型，由于该并联部分存在两条连续转轴，可将其等效成一个三自由度串联机构RPR，进而将整个混联机器人机构等效为一个四自由度串联机构RPRR和一个移动平台的组合进行分析，根据这两部分位姿之间的解耦性，建立了混联机器人完整的位置正反解模型，并用加工球面轨迹的算例验证了所建运动学模型的正确性。提出的5自由度混联机器人所有转动自由度均具有连续转轴，能够得到解析的位置模型表达式，能够很容易实现轨迹规划与运动控制，具有良好的应用前景。
许允斗
,
胡建华
,
张东胜
,
侯照伟
,
姚建涛
,
赵永生
. 一种所有转轴均连续的五自由度混联机器人机构[J]. 机械工程学报, 2018
, 54(21)
: 19
-24
.
DOI: 10.3901/JME.2018.21.019
A new way for constructing a kind of five-degrees-of-freedom hybrid manipulator is proposed based on the distribution of rotational axes of the two rotational degrees of freedom for the parallel mechanisms with two-rotation-and-one-translation. Based on the 2-RPU&UPR parallel mechanism, a novel five-axis hybrid manipulator is constructed. The forward and inverse position models of the 2-RPU&UPR parallel mechanism are established, because this parallel mechanism part has two continuous rotational axes, it can be equivalent to a three-degree-of-freedom serial mechanism of RPR. The whole mechanism of hybrid manipulator is equivalent to a combination of four-degree-of-freedom serial mechanism RPRR and a one-degree-of-freedom mobile platform. According to the pose decoupling between these two parts, the forward and inverse position models of the hybrid manipulator are established. An example of machining a spherical locus is given to verify the correctness of the kinematic models. This five-degree-of-freedom hybrid manipulator with all rotational degrees of freedom being of continuous axes, can get analytical expression of the position models, and can realize the trajectory planning and motion control easily, so it has good application prospects.
[1] LIU N,WU J. Kinematics and application of a hybrid industrial robot-Delta-RST[J]. Sensors &Transducers,2014,169:186-192.
[2] TERRIER M,DUGAS A,HASCOET J Y. Qualification of parallel kinematics machines in high-speed milling on free form surfaces[J]. International Journal of Machine Tools & Manufacture,2004,44(Suppl. 7-8):865-877.
[3] HUNT K H. Structural kinematics of in-parallel-actuated robot-arms[J]. Journal of Mechanisms,Transmissions,and Automation in Design,1983,105(4):705-712.
[4] XIE F G,LIU X J,ZHANG H,et al. Design and experimental study of the SPKM165,a five-axis serial-parallel kinematic milling machine[J]. Science China Technological Sciences,2011,54(5):1193-1205.
[5] WANG Y Y,HUANG T,ZHAO X M,et al,Finite element analysis and comparison of two hybrid robots-the tricept and the trivariant[C]//IEEE/RSJ International Conference on Intelligent Robots and Systems,October 9-15,2006,Beijing. China:IEEE,2006:490-495.
[6] SHI J,WANG Y,ZHANG G,et al. Optimal design of 3-DOF PKM module for friction stir welding[J]. The International Journal of Advanced Manufacturing Technology,2013,66(9-12):1879-1889.
[7] LIAN B,SUN T,SONG Y,et al. Stiffness analysis and experiment of a novel 5-DoF parallel kinematic machine considering gravitational effects[J]. International Journal of Machine Tools & Manufacture,2015,95:82-96.
[8] SICILIANO B. The Tricept robot:Inverse kinematics,manipulability analysis and closed-loop direct kinematics algorithm[J]. Robotica,1999,17:437-445.
[9] SUN T,SONG Y M,LI Y G,et al. Workspace decomposition based dimensional synthesis of a novel hybrid reconfigurable robot[J]. Journal of Mechanisms and Robotics,2010,2(3):031009-1-031009-8.
[10] ZHAO Y Q,JIN Y,ZHOU J. Kinetostatic modeling and analysis of an exechon parallel kinematic machine(PKM) module[J]. Chinese Journal of Mechanical Engineering,2016,29(1):33-44.
[11] SUN T,SONG Y M. Dimensional synthesis of a 3-DOF parallel manipulator based on dimensionally homogeneous Jacobian matrix[J]. Science China Technological Sciences,2010,53(1):168-174.
[12] SCHADLBAUER J,WALTER D R,HUSTY M L. The 3-RPS parallel manipulator from an algebraic viewpoint[J]. Mechanism & Machine Theory,2014,75(5):161-176.
[13] HUANG Z,FANG Y F. Motion characteristics and rotational axis analysis of 3-Dof parallel robot mechanisms[C]//IEEE International Conference on Systems,Man and Cybernetics,October 22-25,1995,Vancouver,BC,Canada. Canada:SMC,1995:67-71.
[14] LI Q,CHEN Q,WU C,et al. Geometrical distribution of rotational axes of 3-[P] [S] parallel mechanisms[J]. Mechanism and Machine Theory,2013,65:46-57.
[15] XU Y D,ZHOU S S,YAO J T,et al. Advances on theory and practice of robots and manipulators[M]. Springer,2014.
[16] 张东胜,许允斗,姚建涛,等. 2RPU/UPR并联机构自由度和位置分析[J]. 机械设计与制造,2014(12):53-56. ZHANG Dongsheng,XU Yundou,YAO Jiantao,et al. Position and DOF analysis of 2RPU/UPR parallel mechanism[J]. Machinery Design & Manufacture,2014(12):53-56.
[17] CHEN Q H,CHEN Z,CHAI X X,et al. Kinematic analysis of a 3-axis parallel manipulator:The P3[J]. Advances in Mechanical Engineering,2013,2013:1-10.
[18] XIE F G,LIU X J,LI T M. Type synthesis and typical application of 1T2R-Type parallel robotic mechanisms[J]. Mathematical Problems in Engineering,2013(2013):1-12.
