针对一种用于月面起飞模拟的九索驱动并联机构，在考虑输入饱和和状态受限的情况下，采用基于反步法的自适应容错控制方法（Adaptive fault tolerant control，AFTC）设计九索并联机构控制器，提升索并联机构在驱动系统故障状态下的运行性能。控制器设计过程中，以乘性误差和加性误差的形式描述驱动系统故障对控制信号的影响，设计带有指令滤波器的辅助系统确保控制信号满足输入饱和条件，采用正切型界限李雅普诺夫方程（Tan-type barrier Lyapunov function，tan-type BLF）设计控制器确保动平台状态满足限制条件。仿真试验表明，基于AFTC方法设计的控制器可以有效辨识控制信号中的乘性误差和加性误差，在考虑输入饱和和状态受限的情况下，位置误差和姿态误差均可以被控制在一定范围内，同时保证控制过程中，九索并联机构索力连续变化且满足索力限制条件。
A novel adaptive fault tolerant control (AFTC) scheme, which is based on backstepping method, is used for the position and attitude tracking of a parallel mechanism driven by nine cables with both multiplicative and additive actuator faults.Both input saturation and full-state constrains are considered. A novel tan-type barrier Lyapunov functions (BLF) is taken to handle the full-state constrains. An auxiliary system is designed to analyze the effect of the input saturation. Simulation confirms that the estimation error of unknown actuator faults are bounded and the position and attitude tracking errors will converge to a neighborhood of zero. Meanwhile, the required full-state constrains and the constrains of cable force will not be violated during operation.
[1] TANG X. An overview of the development for cable-driven parallel manipulator[J]. Advances in Mechanical Engineering,2014,2014(1):1-9.
[2] WANG W,TANG X,SHAO Z,et al. Design and analysis of a wire-driven parallel mechanism for low-gravity environment simulation[J]. Advances in Mechanical Engineering,2014,2014(1):1-11.
[3] ZI B,LI Y. Conclusions in theory and practice for advancing the applications of cable-driven mechanisms[J]. Chinese Journal of Mechanical Engineering,2017,30(4):763-765.
[4] OUYANG B, SHANG W. Rapid optimization of tension distribution for cable-driven parallel manipulators with redundant cables[J]. Chinese Journal of Mechanical Engineering,2016,29(2):231-238.
[5] KRAUS W,SCHMIDT V,RAJENDRA P,et al. System identification and cable force control for a cable-driven parallel robot with industrial servo drives[C]//IEEE International Conference on Robotics and Automation,31 May-7 June,2014,Hong Kong,China. New York:IEEE,2014:5921-5926.
[6] MEUNIER G,BOULET B,NAHON M. Control of an overactuated cable-driven parallel mechanism for a radio telescope application[J]. IEEE Transactions on Control Systems Technology,2009,17(5):1043-1054.
[7] CHELLAL R,LAROCHE E,CUVILLON L. An H∞ methodology for position control of 6-DOF cable-driven parallel robots[C]//European Control Conference. June 24-27,2014,Strasbourg,France. New York:IEEE,2014:358-363.
[8] 保宏,段宝岩,陈光达. 输入不确定的6自由度悬索并联机器人位置控制[J]. 机械工程学报,2007,43(7):128-132. BAO Hong,DUAN Baoyan,CHEN Guangda. Position control of 6-DOF cable-suspended parallel robotic with uncertain input[J]. Chinese Journal of Mechanical Engineering,2007,43(7):128-132.
[9] 刘志远,陈炼,邵珠峰,等. FAST馈源支撑系统的终端精度保证研究[J]. 机械工程学报,2017,53(17):50-59. LIU Zhiyuan,CHEN Lian,SHAO Zhufeng,et al. Terminal accuracy of the feed support system in FAST[J]. Journal of Mechanical Engineering,2017,53(17):50-59.
[10] 訾斌,段宝岩,杜敬利,等. 一种柔索并联机器人的动力学建模与主动控制[J]. 振动与冲击,2007,26(3):96-100. ZI Bin,DUAN Baoyan,DU Jingli. Modeling and active control of a cable-suspended parallel manipulator[J]. Journal of Vibration and Shock,2007,26(3):96-100.
[11] 曹凌,唐晓强,王伟方. 基于定矢量力输出的八索并联机构索力优化及实验研究[J]. 机器人,2015,37(6):641-647. CAO Ling,TANG Xiaoqiang,WANG Weifang. Tension optimization and experimental research of parallel mechanism driven by 8 cables for constant vector force output[J]. Robot,2015,37(6):641-647.
[12] 游贤强,陈伟海,崔翔,等. 基于后推技术的绳驱动拟人肩关节动力学控制[J]. 北京航空航天大学学报,2012,38(12):1671-1675. YOU Xianqiang,CHEN Weihai,CUI Xiang,et al. Dynamic control of a cable-driven humanoid-shoulder joint based on backstepping technique[J]. Journal of Beijing University of Aeronautics and Astronautics,2012,38(12):1671-1675.
[13] LAM Q M,DRAKE D T,RIDGELY D B. Input saturation treatments:A performance comparison of direct adaptive control and θ-D control methodologies[C]//IEEE Aerospace Conference,IEEE,2007:1-15.
[14] TEE K P,GE S S,LI H,et al. Control of nonlinear systems with time-varying output constraints[C]//IEEE International Conference on Control and Automation,IEEE,2010:2511-2516.
[15] CHEN M,GE S S,HOW B V. Robust adaptive neural network control for a class of uncertain MIMO nonlinear systems with input nonlinearities[J]. IEEE Transactions on Neural Networks,2010,21(5):796-812.
[16] JIN X,XU J. A barrier composite energy function approach for robot manipulators under alignment condition with position constraints[J]. International Journal of Robust & Nonlinear Control,2014,24(17):2840-2851.
[17] JIN X,XU J X. Iterative learning control for output-constrained systems with both parametric and nonparametric uncertainties[M]. Oxford:Pergamon Press, 2013.
[18] JIN X. Adaptive fault tolerant control for a class of input and state constrained MIMO nonlinear systems[J]. International Journal of Robust & Nonlinear Control,2016,26(2):286-302.
[19] BORGSTROM P H,JORDAN B L,SUKHATME G S,et al. Rapid computation of optimally safe tension distributions for parallel cable-driven robots[J]. IEEE Transactions on Robotics,2009,25(6):1271-1281.
[20] DIAO X,MA O. Force-closure analysis of 6-dof cable manipulators with seven or more cables[J]. Robotica,2009,27(2):209-215.
[21] 魏青铜,陈谋,吴庆宪. 输入饱和与姿态受限的四旋翼无人机反步姿态控制[J]. 控制理论与应用,2015,32(10):1361-1369. WEI Qingtong,CHEN Mou,WU Qingxian. Backstepping-based attitude control for a quadrotor UAV with input saturation and attitude constrains[J]. Control Theory & Applications,2015,32(10):1361-1369.
[22] DIAO X,MA O. Workspace analysis of a 6-DOF cable robot for hardware-in-the-loop dynamic simulation[C]//IEEE/RSJ International Conference on Intelligent Robots and Systems,IEEE,2007:4103-4108.
