基于UDE的掘进机器人非奇异终端滑模控制

Non-singular terminal sliding mode control of tunneling robot based on UDE

  • 摘要: 随着科学技术的不断进步,煤矿悬臂式掘进机正朝着自动化、少人化、智能化的方向发展。巷道断面成形是悬臂式掘进机的一个主要任务,针对煤矿掘进机器人截割头轨迹控制易受外界未知干扰、系统非线性以及参数不确定性等因素影响,提出一种基于未知动态估计器(Unknown Dy-namic Estimator,UDE)的非奇异终端滑模控制方法。首先,考虑液压驱动部分建立了掘进机截割电液驱动系统的3阶非线性严反馈状态空间模型。其次,利用有限时间状态收敛的超螺旋滑模微分器估计系统的未知速度状态,基于低通滤波器设计UDE估计系统的非匹配项集总不确定性,并采用非奇异终端滑模面和幂指数趋近律设计快速终端滑模控制律,对UDE观测的系统扰动进行实时前馈补偿可有效缓解传统滑模控制存在的控制器抖振问题。同时为降低高阶虚拟控制量导数计算复杂度,引入指令滤波技术,并采用高增益鲁棒反馈抑制系统匹配项扰动,利用李雅普诺夫准则证明闭环系统的稳定性。最后,利用搭建的掘进机器人样机开展实验验证。试验结果表明:在跟踪阶跃信号、0.1 Hz正弦信号以及混频信号时,所提出的控制方法相较传统的PI控制跟踪误差的平均值分别降低了61.60%、66.51%、66.27%,跟踪误差的均方根值分别降低了54.00%、64.53%、61.90%,可有效地抑制系统的多源不确定性扰动,进而实现掘进机器人截割系统的高精度位置控制与动态快速响应。

     

    Abstract: With the rapid development of science and technology, the coal mine boom-type roadheader is developing towards the direction of automation, fewer people, and more intelligence. The formation of roadway sections is the main task of the boom-type roadheader. A non-singular terminal sliding mode control method based on an unknown dynamic estimator (UDE) is proposed aiming at the trajectory control of the cutting head for the coal mine tunneling robot, which is affected by unknown external disturbance, system nonlinearity, and parametric uncertainty. Firstly, considering the hydraulic driving system, a 3-order nonlinear strict feedback state-space model of the roadheader cutting electro-hydraulic driving system is established. Secondly, a super spiral sliding mode differentiator with finite time state convergence is used to estimate the unknown speed state of the system. The UDE is designed based on a low-pass filter to estimate the lumped uncertainty of the unmatched items of the system, and a fast terminal sliding mode control law is designed using a nonsingular terminal sliding mode surface and a power exponential reaching law. Real-time feedforward compensation for the system disturbances observed by the UDE can effectively alleviate the controller chattering problem existing in traditional sliding mode control. At the same time, in order to reduce the computational complexity of derivatives of high-order virtual control variables, the command filtering technology is introduced, and high gain robust feedback is used to suppress the disturbance of system matching terms. The stability of the closed-loop system is proved by using the Lyapunov synthesis method. Finally, the prototype of the tunneling robot is utilized to carry out experimental verification. The experimental results show that when tracking step signals, 0.1 Hz sinusoidal signals, and mixed frequency signals, the average value of the tracking error of the proposed control method is reduced by 61.60%, 66.51%, and 66.27% respectively compared with the traditional PI control. And the root mean square value of the tracking error is reduced by 54.00%, 64.53%, and 61.90% respectively. The algorithm can effectively suppress the multi-source uncertainty disturbance of the system, and realize the high-precision position control and dynamic fast response of the cutting system of the roadheader robot.

     

/

返回文章
返回