Abstract:This research aims to systematically solve the obstacle avoidance problem of the long-arm redundant robot painting the inner surface of complex ducts. Firstly, an online collision detection method is proposed based on spatial interpolation. The method is universal for different shapes of ducts, and the accuracy increases with the sample density. Because the position and posture of the robot end link is determined by constraints of the goal position and posture. The obstacle avoidance of end link cannot be performed by redundant degrees of robot. As for inevitable end collision, a method of relaxing the target point attitude constraint is proposed. The collision avoidance direction is used to determine the fastest escape direction of robot end link, and the minimum posture change matrix is calculated for satisfying obstacle avoidance requirements. At the same time, the obstacle avoidance ability of other joints of the redundant robot is optimized, by proposing a optimization algorithm based on the virtual axis of the duct and the fastest escape direction of each joint. The simulation results of the inner surface painting of complex duct verify the effectiveness of the proposed method, solving inevitable end collision problem and improving obstacle avoidance ability of the robot. Compared with the existing methods, the method can deal with the obstacle avoidance problems in more complicated ducts.
[1] Okamoto Jr. J, Adamowski J C, Tsuzuki M S G, et al. Autonomous system for oil pipelines inspection[J]. Mechatronics, 1999, 9(7):731-743.
[2] 刘晓洪,郑毅,高隽恺,等.新型蠕动式气动微型管道机器人[J].液压气动与密封,2007,27(1):16-18.Liu X H, Zheng Y, Gao J K, et al. A new type of squirmy pneumatic micro-pipeline robot[J]. Hydraulics Pneumatics & Seals, 2007, 27(1):16-18.
[3] 张淑珍,杨萍,袁晓鹏.管道清灰机器人系统设计[J].机械设计与制造,2006(8):125-127.Zhang S Z, Yang P, Yuan X P. Design of in-pipe clearing ash robot system[J]. Machinery Design & Manufacture, 2006(8):125-127.
[4] 梅江平,杨志永,张大卫.喷漆机器人尺寸优化设计及控制系统总体规划[J].组合机床与自动化加工技术,2004(10):62-64.Mei J P, Yang Z Y, Zhang D W. Optimized dimension design and NC scheme layout of painting robot[J]. Modular Machine Tool & Automatic Manufacturing Technique, 2004(10):62-64.
[5] Chen Y, Chen W Z, Chen K, et al. Mechanism configuration of super-redundant robot[M]//Advanced Materials Research, Vol.744. Durnten-Zurich, Switzerland:Trans Tech Publications Ltd., 2013:68-73.
[6] Lozano-Perez T. Automatic planning of manipulator transfer movements[J]. IEEE Transactions on Systems, Man, and Cybernetics, 1980, 11(10):681-698.
[7] Khatib O. Real-time obstacle avoidance for manipulators and mobile robots[M]//Autonomous Robot Vehicles. New York, USA:Springer-Verlag, 1986:500-505.
[8] Liegeois B A. Automatic supervisory control of the configuration and behavior of multibody mechanisms[J]. IEEE Transactions on Systems, Man, and Cybernetics, 2007, 7(12):868-871.
[9] 贾庆轩,张倩茹,高欣,等.预选择最小距离指标的冗余机器人动态避障算法[J].机器人,2013,35(1):17-22.Jia Q X, Zhang Q R, Gao X, et al. Dynamic obstacle avoidance algorithm for redundant robots with pre-selected minimum distance index[J]. Robot, 2013, 35(1):17-22.
[10] 张立栋,李亮玉,王天琪.冗余度机器人梯度投影避障算法的改进[J].机械科学与技术,2015,34(10):1511-1516.Zhang L D, Li L Y, Wang T Q. Improvement of obstacle avoidance algorithm for a redundant robot based on gradientprojection method[J]. Mechanical Science and Technology for Aerospace Engineering, 2015, 34(10):1511-1516.
[11] 高涵,张明路,张小俊,等.冗余机器人的任务优先级轨迹规划方法[J].机械科学与技术,2018, 37(1):24-29.Gao H, Zhang M L, Zhang X J, et al. An approach for task priority trajectory planning of redundant robots[J]. Mechanical Science and Technology for Aerospace Engineering, 2018, 37(1):24-29.
[12] 申浩宇,吴洪涛,陈柏,等.基于主从任务转化的冗余度机器人避障算法[J].机器人,2014,36(4):425-429.Shen H Y, Wu H T, Chen B, et al. Obstacle avoidance algorithmfor redundant robots based on transition between the primary and secondary tasks[J]. Robot, 2014, 36(4):425-429.
[13] 胡平,刘璇,张建华.一种任务转化的动态避障算法[J].机械设计与制造,2018(7):55-58.Hu P, Liu X, Zhang J H. Algorithm for dynamic obstacle avoidance based on the transformation of tasks[J]. Machinery Design & Manufacture, 2018(7):55-58.
[14] 徐朋,赵东标,程锦翔,等.冗余机器人逆运动学解流形的多目标优化[J].机器人,2016,38(6):704-710.Xu P, Zhao D B, Cheng J X, et al. Multi-objective optimization for inverse kinematics solution manifolds of redundant robots[J]. Robot, 2016, 38(6):704-710.
[15] 邵君奕,张传清,陈雁,等.用于空间内曲面喷涂的冗余度机器人轨迹规划方法[J].清华大学学报(自然科学版),2014(6):799-804.Shao J Y, Zhang C Q, Chen Y, et al. Trajectory planning for redundant robots for internal surface spraying[J]. Journal of Tsinghua University (Science & Technology), 2014(6):799-804.
[16] Chen W Z, Chen Y, Li B, et al. Design of redundant robot painting system for long non-regular duct[J]. Industrial Robot, 2015, 43(1):58-64.