Chand Ravinesh, Chand Ronal Pranil, Kumar Sandeep Ameet
School of Mathematical and Computing Sciences, Fiji National University, Suva, Fiji.
School of Information Technology, Engineering, Mathematics and Physics, University of the South Pacific, Suva, Fiji.
PeerJ Comput Sci. 2022 Feb 11;8:e885. doi: 10.7717/peerj-cs.885. eCollection 2022.
Robotic arms play an indispensable role in multiple sectors such as manufacturing, transportation and healthcare to improve human livelihoods and make possible their endeavors and innovations, which further enhance the quality of our lives. This paper considers such a robotic arm comprised of revolute links and a prismatic end-effector, where the articulated arm is anchored in a restricted workspace. A new set of stabilizing switched velocity-based continuous controllers was derived using the Lyapunov-based Control Scheme (LbCS) from the category of classical approaches where switching of these nonlinear controllers is invoked by a new rule. The switched controllers enable the end-effector of the robotic arm to navigate autonomously a series of landmarks, known as hierarchal landmarks, and finally converge to its equilibrium state. The interaction of the inherent attributes of LbCS that are the safeness, shortness and smoothness of paths for motion planning bring about cost and time efficiency of the controllers. The stability of the switched system was proven using Branicky's stability criteria for switched systems based on multiple Lyapunov functions and was numerically validated using the RK4 method (Runge-Kutta method). Finally, computer simulation results are presented to show the effectiveness of the continuous time-invariant velocity-based controllers.
机器人手臂在制造、运输和医疗保健等多个领域发挥着不可或缺的作用，以改善人类生活，并使他们的努力和创新成为可能，进而提高我们的生活质量。本文考虑了一种由旋转连杆和棱柱形末端执行器组成的机器人手臂，其中关节臂固定在一个受限的工作空间内。利用基于李雅普诺夫的控制方案（LbCS），从经典方法类别中推导了一组新的基于切换速度的连续稳定控制器，这些非线性控制器的切换由一个新规则触发。切换控制器使机器人手臂的末端执行器能够自主导航一系列地标，即分层地标，并最终收敛到其平衡状态。LbCS固有属性（即运动规划路径的安全性、短路径性和平滑性）的相互作用带来了控制器的成本和时间效率。基于多个李雅普诺夫函数，使用布兰尼基切换系统稳定性准则证明了切换系统的稳定性，并使用龙格 - 库塔方法（RK4方法）进行了数值验证。最后，给出了计算机仿真结果，以展示基于连续时间不变速度的控制器的有效性。
