School of Mechanical Engineering, Hefei University of Technology, Hefei 230009, China.
Sensors (Basel). 2018 Sep 1;18(9):2898. doi: 10.3390/s18092898.
Three-dimensional (3D) printing technology has been greatly developed in the last decade and gradually applied in the construction, medical, and manufacturing industries. However, limited workspace and accuracy restrict the development of 3D printing technology. Due to the extension range and flexibility of cables, cable-driven parallel robots can be applied in challenging tasks that require motion with large reachable workspace and better flexibility. In this paper, a cable-driven parallel robot for 3D Printing is developed to obtain larger workspace rather than traditional 3D printing devices. A kinematic calibration method is proposed based on cable length residuals. On the basis of the kinematic model of the cable-driven parallel robot for 3D Printing, the mapping model is established among geometric structure errors, zero errors of the cable length, and end-effector position errors. In order to improve the efficiency of calibration measurement, an optimal scheme for measurement positions is proposed. The accuracy and efficiency of the kinematics calibration method are verified through numerical simulation. The calibration experiment based on the motion capture system indicates that the position error of end-effector is decreased to 0.6157 mm after calibration. In addition, the proposed calibration method is effective and verified for measurement positions outside optimal positions set through experiments.
三维（3D）打印技术在过去十年中得到了极大的发展，并逐渐应用于建筑、医疗和制造业。然而，有限的工作空间和精度限制了 3D 打印技术的发展。由于电缆的延伸范围和灵活性，缆索驱动的并联机器人可应用于需要大可达工作空间和更好灵活性的挑战性任务。本文开发了一种用于 3D 打印的缆索驱动并联机器人，以获得更大的工作空间，而不是传统的 3D 打印设备。提出了一种基于缆索长度残差的运动学标定方法。在 3D 打印缆索驱动并联机器人运动学模型的基础上，建立了几何结构误差、缆索长度零位误差和末端执行器位置误差之间的映射模型。为了提高标定测量的效率，提出了一种测量位置的优化方案。通过数值模拟验证了运动学标定方法的准确性和效率。基于运动捕捉系统的标定实验表明，标定后末端执行器的位置误差降低到 0.6157mm。此外，通过实验验证了测量位置不在最优位置集时，所提出的标定方法也是有效的。
