Abstract:An inverse kinematics algorithm with improved tip following movement is proposed to solve the problems of expensive computational cost, exceeding joint limits and large configuration deviation for the inverse kinematics of hyper-redundant snake-arm robots. Constraints on the bending angles of snake arm are introduced to the tip-following method. And the update mode of the joint position is adjusted to make joints locate on the axis of the snake arm. By updating the spatial position of joints successively, the inverse kinematics of the hyper-redundant multi-section arm is converted into the inverse kinematics of a single-section arm with 2 degree-of-freedoms. Finally, the trajectory tracking effects of the snake-arm robot with the base moving, and also with the base fixed, are analyzed by simulation, and the performances of different methods under the same target position are compared. Results show that the improved algorithm can ensure that the bending angles do not exceed the given range and the amount of joint movement is diminishing from the tip to the base, yielding a more concordant movement. Compared with the Jacobian-based numerical method and the existing heuristic methods, the computational cost is decreased and the generated configuration deviation of the whole robot is reduced using the proposed method, which is more applicable for the real-time control of a snake-arm robot.
[1] Buckingham R, Chitrakaran V, Conkie R, et al. Snake-arm robots:A new approach to aircraft assembly[R/OL]//SAE Technical Paper. (2007-09-17)[2016-09-01]. http://papers.sae.org/2007-01-3870/.
[2] 姚艳彬,杜兆才,魏志强.蛇形臂机器人装配系统研究[J].航空制造技术,2015,491(21):26-30.Yao Y B, Du Z C, Wei Z Q. Research on the snake-arm robot assembly system[J]. Aeronautical Manufacturing Technology, 2015, 491(21):26-30.
[3] Buckingham R, Graham A. Snaking around in a nuclear jungle[J]. Industrial Robot, 2005, 32(2):120-127.
[4] Simaan N, Taylor R, Flint P. A dexterous system for laryngeal surgery[C]//IEEE International Conference on Robotics and Automation. Piscataway, USA:IEEE, 2004:351-357.
[5] Wolf A, Brown H B, Casciola R, et al. A mobile hyper redundant mechanism for search and rescue tasks[C]//IEEE/RSJ International Conference on Intelligent Robots and Systems. Piscataway, USA:IEEE, 2003:2889-2895.
[6] Hannan M W, Walker I D. Kinematics and the implementation of an elephant's trunk manipulator and other continuum style robots[J]. Journal of Field Robotics, 2003, 20(2):45-63.
[7] Godage I S, Branson D T, Guglielmino E, et al. Path planning for multisection continuum arms[C]//IEEE International Conference on Mechatronics and Automation. Piscataway, USA:IEEE, 2012:1208-1213.
[8] 阳方平,李洪谊,王越超,等.一种求解冗余机械臂逆运动学的优化方法[J].机器人, 2012,34(1):17-21,31.Yang F P, Li H Y, Wang Y C, et al. An optimization method for solving the inverse kinematics of redundant manipulator[J]. Robot, 2012, 34(1):17-21,31.
[9] Williams Ⅱ R L, Mayhew IV J B. Obstacle-free control of the hyper-redundant NASA inspection manipulator[C]//Proceed-ings of the 5th National Conference on Applied Mechanics and Robotics. Cincinnati, USA:ASME. 1997:12-15.
[10] Coimbra A P, CrisÃ'stomo M M, Ferreira J Ã. Position and anti-collision algorithms for a 3D hyper-redundant robot[C]//6th IFAC Conference on Management and Control of Production and Logistics. Laxenburg, Austria:IFAC, 2013:572-576.
[11] Cho C N, Jung H, Son J, et al. An intuitive control algorithm for a snake-like natural orifice transluminal endoscopic surgery platform:A preliminary simulation study[J]. Biomedical Engineering Letters, 2016, 6(1):39-46.
[12] Tappe S, Pohlmann J, Kotlarski J, et al. Towards a follow-the-leader control for a binary actuated hyper-redundant manipulator[C]//IEEE/RSJ International Conference on Intelligent Robots and Systems. Piscataway, USA:IEEE, 2015:3195-3201.
[13] Sreenivasan S, Goel P, Ghosal A. A real-time algorithm for simulation of flexible objects and hyper-redundant manipulators[J]. Mechanism and Machine Theory, 2010, 45(3):454-466.
[14] Aristidou A, Lasenby J. FABRIK:A fast, iterative solver for the inverse kinematics problem[J]. Graphical Models, 2011, 73(5):243-260.
[15] Ananthanarayanan H, Ordóñez R. Real-time inverse kinematics of (2n+1) DOF hyper-redundant manipulator arm via a combined numerical and analytical approach[J]. Mechanism and Machine Theory, 2015, 91:209-226.
[16] Palmer D, Cobos-Guzman S, Axinte D. Real-time method for tip following navigation of continuum snake arm robots[J]. Robotics and Autonomous Systems, 2014, 62(10):1478-1485.
[17] Craig J J. Introduction to robotics:Mechanics and control[M]. Upper Saddle River, UK:Pearson Prentice Hall, 2005.