【作者】 范超；

【导师】 郝明晖；

【作者基本信息】 哈尔滨工业大学 ， 机械设计及理论， 2010， 硕士

【摘要】 作为工业机器人家族的一员,工业用大型机器人被广泛应用于汽车制造、造纸、食品、玻璃生产等行业。交流伺服具有响应快、精度高、调速性能好等优点,被广泛应用于工业机器人中。然而由于大型机器人操作臂的负载、自重较大,运动过程中巨大的偏重力矩与耦合力矩对驱动系统提出了很高的要求,给交流伺服系统在大型机器人中的应用带来了困难。针对此点,本文从机构设计、轨迹规划及控制三方面出发对工业用大型机器人操作臂进行展开研究。操作臂机构设计方面,为了增加操作臂运动的灵活性,以最大工作空间为优化目标对操作臂臂长参数进行了优化;为了减少偏重力矩的影响,设计了肩关节的偏重力矩平衡机构;为了降低驱动系统负载、提高系统刚度、减小振动,设计了带有局部闭环肘关节的配重机构及腕关节驱动机构;并对操作臂的主要零件进行了有限元受力分析。操作臂轨迹规划方面,为了充分利用永磁同步电机的过载能力,降低所需电机的额定转矩,以操作臂运动过程中的功率最大值及方差构造目标函数;为了保证运动的平稳性,采用五次插值曲线作为离散点间的插值曲线,利用矩阵对约束方程组进行求解,大大简化了大量约束条件下插值曲线系数的求解问题,并利用遗传算法完成轨迹参数的优化;为了验证文中轨迹规划的有效性,建立Adams仿真平台,并进行对比仿真实验,结果表明:与普通的五次插值法相比,采用文中方法所得到的轨迹,运动过程中各驱动系统功率幅值减小明显,达到了通过轨迹规划减小驱动系统负担的目的。操作臂控制方面,建立了三相永磁同步电机控制模型;以基于确定轨迹运动的大型操作臂作为研究对象,采用根据位置指令查表的方法对运动过程中的扰动量进行前馈补偿,并建立了前馈控制系统的电流环、速度环控制模型;为了验证文中前馈控制方法的有效性,以Adams软件中操作臂模型为被控对象,搭建了Matlab-Adams联合仿真平台,并与普通PID控制进行比较仿真,仿真结果表明,采用文中的前馈控制方案可以完成对确定轨迹的操作臂控制,并且控制效果明显好于普通PID控制。更多还原

【Abstract】 As an important member in industrial robot family, large industrial manipulator was widely used in automobile manufacturing, paper making, food, glass production industries; benefited for fast response, high precision and speed control performance, AC servo was widely used in industrial robots, but because great load and deadweight existed in the moving process, a huge gravity and coupling torque propose a high demand for the AC servo system, at the same time, difficulties are made for AC servo applicated in manipulator. On this point, this paper takes a expanded study on large-scale industrial manipulator with four degrees of freedom, by the aspects of structural design, trajectory planning, and control strategy.In manipulator structure design aspect, the structure with local closed loop was adopted; in order to increasing the flexibility in the moving process, took the maximum of working space as the optimal target; in order to releasing the impact of gravity torque, the balance mechanism for shoulder joint and counter balance mechanism for elbow joint had been designed; and the stress analysis of main parts were also accomplished by the finite element software.In manipulator trajectory planning design aspect, in order to reduce the burden of motor drive system in large torque output condition, according to the relationship between motor back-EMF voltage equation and output torque in voltage equitation, established the optimal function by maximum power and variance objective function in the moving progress; To ensure the smooth character in the movement, using the five order interpolated curve as the curve between discrete points, and using matrix to solve the constraint equations, greatly simplifies the solving progress on interpolation curve parameters under lots of motion constrained conditions, and take advantages of genetic algorithm to complete trajectory parameters optimization; In order to verify the validity of the text in the trajectory planning, Adams virtual prototyping simulation platform was established, by comparing simulation, the results showed that compared to the ordinary planning trajectory, the drive system power amplitude of five interpolation which was obtained by the study, had a significantly reduced, reached the purposes of releasing drive system burden by trajectory planning.In manipulator control aspect, established a three-phase permanent magnet synchronous motor(PMSM) control model; take the large manipulator which working in a invariable trajectory as the study object, by look-up table method according to the position instruction, feedforward compensation was adopted to the conquer disturbance in the movement, established the current loop, velocity loop control model for feedforward control system; in order to verify the validity of feed-forward control method in the paper, adopted Adams virtual prototype model as the control object, and established Matlab-Adams combine simulation platform, carried out the comparison of simulation with ordinary PID control, the results illustrate that the control of large manipulator which working in a invariable trajectory can be done by the method in the paper, what is more, the control effect is manifest better than the normal PID control .更多还原