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凿岩机器人双三角钻臂自适应控制策略研究
Research on Adaptive Control Strategy of Double Triangle Boom of Rock-drilling Robot
【作者】 李力争;
【导师】 何清华;
【作者基本信息】 中南大学 , 机械电子工程, 2003, 博士
【摘要】 应用计算机实现液压凿岩台车的高度自动化是当今世界各国液压凿岩设备发展的主流,而双三角钻臂因为性能优良而被广泛应用于液压凿岩台车中。双三角钻臂属于直接定位钻臂,在工作区间可将钎头直接移位到目标位置。为了防止干涉、实现直接和精确定位,需要控制钻臂严格按规划轨迹移位。论文以实现双三角钻臂轨迹跟踪定位控制为目的,从双三角定位机构这一实际非线性对象出发,而展开对一般非线性系统的辨识、预测与控制的研究,然后将研究结果又回过来应用于双三角钻臂这一特定对象,主要内容如下。 论述了国内外液压凿岩设备的发展概况及非线性控制系统的研究现状,对双三角钻臂移位控制策略和方案选择进行了论证,指出了采用自适应控制策略的合理性;根据双三角钻臂的结构和运动特性,建立了直角坐标系和斜角坐标系,通过几何分析导出了钻臂各物理量之间的变换或换算关系,为双三角钻臂各液压缸运动速度的决策和钻臂位姿检测过程中的标度变换打下了基础;在分析了双三角钻臂运动特性的基础上,提出了一种双三角钻臂支臂缸运动速度的全程决策方法,为实现双三角钻臂平稳运行和直接定位控制创造了条件;从液压系统的基本方程入手,建立了双三角钻臂平行联动机构的简化模型,导出了连续时间输入输出传递函数、连续时间状态空间表达式、离散时间输入输出模型和离散时间状态空间表达式四种模型形式,通过对钻臂的结构和受力分析,导出了模型中的参数和液压缸负载力的估算公式和估算方法,为控制系统设计和仿真研究打下了基础;在介绍了确定性非线性系统和随机非线性系统的回归输入输出模型的基础上,给出并证明了随机非线性系统的时变线性模型的存在性定理,通过分析系统闭环预测存在的缺陷,并为了改善闭环预测性能,为一般系统提出了三类更简便实用的输入输出离散时间模型:即非齐次时变线性模型、非齐次增量型时变线性模型和增量型一元线性回归模型,给出并证明了其存在性定理;针对增量型一元线性回归模型推出了投影算法、加权限定记忆回归法的参数估计算式,并提出了一种新的滚动多模型加权平均参数估计算法,针对非齐次时变线性模型和增量型非齐次时变线性模型给出了渐消记忆递推最小二乘法和投影算法的参数估计算式,上述模型及其相应的参数估计方法为结构未知的一般系统的辨识与预测提供了便利;应用稳态运行时阀控液压缸的运行速度与电液比例伺服放大器输入电压的近似比例关系,并应用前一采样时刻对象的输入输出数据来确立这种关系,提出了保持两支臂缸运行速度之比为给定值的静态速比自适应控制方案;应用自适应广义预测控制理论,针对双三角钻臂具体的CARIMA模型,推出了具体的自适应广义预测控制算法;沿用自适应广义预测控制的理论与方法,提出了分别基于上述三类模型的自适应多步预测控制策略和自适应单步预测控制策略;分别采用上述三类模型的逆作为逆控制器,并与一阶滤波器串联构成双重自校正控制器,引入智能控制的基本方法,在控制过程中通过监测模型特征来作出控制决策,形成了以自适应逆控制为主、常规控制为辅的智能自适应逆控制策略;对原有双三角钻臂凿岩台车进了改造,设计和研制了一套完整的凿岩机器人两级计算机控制系统,在这一实验平台上对双三角钻臂控制系统进行了实验研究,完成了上述各种控制策略的验证工作,实现了基于上述各种控制策略的双三角钻臂直接定位控制。 论文为实现双三角钻臂轨迹跟踪和精确定位控制提供了一套完整了理论与方法,有关非线性控制系统的研究成果可推广应用于一般工业生产过程的控制。
【Abstract】 Using computer to realize the highly automation of hydraulic drill rig is a chief development of hydraulic rock drilling equipment, and double triangle boom is widely used in hydraulic drill rig for its fine behavior. Double triangle boom is a kind of directly positioning mechanism, it can remove the drill rod to a target position directly in its operating range. In order to avoid interference and realize direct and accurate positioning, it is necessary to control the boom to along a planed track precisely. Starting from the practical nonlinear object of the double triangle positioning mechanism, and aiming at the control for trajectory tracking and positioning of the boom, this paper makes research on identification, prediction and control of general nonlinear systems, and then uses the result back to the special object of the boom. The main contents are as follows.Firstly, the development of hydraulic rock-drilling equipment at home and abroad is surveyed, the status quo of the research on nonlinear control system is discussed, and the selection of the motion control strategy of double triangle boom is demonstrated, then the reasonableness of adopting adaptive control strategy is pointed out. Secondly, according to the structure and the motion characteristic of double triangle boom, a rectangular coordinates and a oblique coordinates are set up, then the dimension relation relevant to the boom is derived from geometrical analysis, thus laying the basis for the moving velocity programming of the supporting cylinders and the scale conversion in the measurement of the posture of the boom. Thirdly, by analyzing the motion characteristic of the boom, a method for the whole course moving velocity programming of the supporting cylinders of the boom is presented, and thereby the condition to control the boom for stable motion and directly positioning is created. Fourthly, starting with the basic equations of hydraulic systems, by modeling the boom and its hydraulic system in mechanism, a simplified model of the parallel translation linkage of the boom is obtained, and the four model forms of input-output continuous-time transfer function, continuous-time statespace expression, input-output discrete-time model and discrete-time statespace expression are deduced. By analyzing the structure of the boom and the load-bearing of the cylinders, the formulas and the methods for estimating the model parameters and the bearing force of the cylinders are presented. As a result, the foundation for the control system design and simulation is set up. Fifthly, after the recursive input-output models of deterministic and stochastic nonlinear systems being introduced, the existence theorem of the time-varying linear model for describing stochastic nonlinear systems is given and demonstrated. By analyzing the defect and in order to improve the behavior of the closed loop prediction of systems, three novel practical input-output discrete-time models: an inhomogeneous time-varying linear model, an inhomogeneous incremental time-varying linear model and an incremental simple linear regression model are put forward, the existence theorem of the three models are also given and demonstrated. Sixthly, in order to estimate the parameters of the incremental simple regression model, a projection algorithm and a weighted limited memory regression algorithm are deduced, and a new rolling multiple model weighted average algorithm is proposed. A recursive least squares with forgetting factor algorithm and a projection algorithm are also given to estimate the parameters of the inhomogeneous time-varying linear model and the inhomogeneous incremental time-varying linear model. The three models and therelative parameter estimation approach provide general systems with unknown structure with facilities for identification and prediction. Seventhly, as we know, the moving velocity of valve-controlled cylinders is approximately proportional to the input voltage of the servo amplifier of electro-hydraulic proportional valve when the cylinders are in st
【Key words】 rock-drilling robot; double triangle boom; nonlinear system; positioning control; adaptive control;