Research trends in methods for controlling macro-micro motion platforms

With ongoing economic,scientific,and technological developments,the electronic devices used in daily lives are developing toward precision and miniaturization,and so the demand for high-precision manufacturing machinery is expanding.The most important piece of equipment in modern high-precision manufacturing is the macro-micro motion platform(M3P),which offers high speed,precision,and efficiency and has macro-micro motion coupling characteristics due to its mechanical design and composition of its driving components.Therefore,the design of the control system is crucial for the overall precision of the platform;conventional proportional–integral–derivative control cannot meet the system requirements,and so M3Ps are the subject of a growing range of modern control strategies.This paper begins by describing the development history of M3Ps,followed by their platform structure and motion control system components,and then in-depth assessments of the macro,micro,and macro-micro control systems.In addition to examining the advantages and disadvantages of current macro-micro motion control,recent technological breakthroughs are noted.Finally,based on existing problems,future directions for M3P control systems are given,and the present conclusions offer guidelines for future work on M3Ps.

Research on Contour Error Based on CNC Multi-axis Motion Control System

The contour error was analyzed based on CNC multi-axis motion control, the contour error model was obtained focused on beeline and different radius of curvature and common contour of curve, for a CNC biaxial motion control system and the mechanism of producing contour error and the relationship between tracking error and contour error were presented. The theoretical and practical significance of modeling error and controlling error in motion control systems was carried out.

Adaptive Sliding Control of Six-DOF Flight Simulator Motion Platform

There is proposed an adaptive sliding controller in task space on the base of the linear Newton-Euler dynamic equation of motion platform in a six-DOF flight simulator. The uncertain parameters are divided into two groups： the constant and the time-varying. The controller identifies constant uncertain parameters using nonlinear adaptive controller associated with elimination of the influences of time-varying uncertain parameters and compensation of the external disturbance using sliding control. The results of numerical simulation attest to the capability of this control scheme not only to, with deadly accuracy, identify parameters of motion platform such as load, inertia moments and mass center, but also effectively improve the robustness of the system.

Platform motion minimization using model predictive control of a floating offshore wind turbine

Wind turbines are installed offshore with the assistance of a floating platform to help meet the world’s increasing energy needs.However,the incident wind and extra incident wave disturbances have an impact on the performance and operation of the floating offshore wind turbine(FOWT)in comparison to bottom-fixed wind turbines.In this paper,model predictive control(MPC)is utilized to overcome the limitation caused by platform motion.Due to the ease of control synthesis,the MPC is developed using a simplified model instead of high fidelity simulation model.The performance of the controller is verified in the presence of realistic wind and wave disturbances.The study demonstrates the effectiveness of MPC in reducing platform motions and rotor/generator speed regulation of FOWTs.

AUV Modeling and Motion Control Strategy Design

To provide a suitable model for AUV simulation and control purposes, a general nonlinear dynamic model including a novel thruster hydrodynamics model was derived. Based on the modeling method, the "AUV-XX" simulation platform was established to carry out fundamental tests on its motion characteristics, stability, and controllability. A motion control strategy consisting of both position and speed control in a horizontal plane was designed for different task assignments of underwater vehicles. Combined control of heave and pitch was adopted to compensate for the reduction of vertical tunnel thrusters when the vehicle is moving at a high speed. An improved S-surface controller based on the capacitor plate model was developed with flexible gain selections made possible by different forms of restricting the error and changing the rate of the error. Simulation results show that the derived general mathematical model together with simulation platform can provide a test bed for fundamental tests of motion control. Additionally, the capacitor plate model S-surface control shows a good performance in guiding the vehicle to achieve the desired position and speed with sufficient accuracy.

漂浮式海上风力机自适应超螺旋滑模桨距控制

针对额定风速以上漂浮式海上风力机系统的输出功率稳定、浮式平台运动和疲劳载荷抑制任务目标,考虑系统非线性和模型参数摄动及风浪扰动,提出一种基于自适应超螺旋二阶滑模和干扰观测补偿的桨距角鲁棒控制方案。首先,实现漂浮式海上风力机的仿射非线性不确定系统建模;其次,构建考虑风力机额定转速和平台纵摇的滑模函数,设计控制增益自适应调节的超螺旋二阶滑模控制律;再次,采用干扰观测器补偿模型参数摄动和风浪扰动不确定项;最后,基于FAST与Matlab/Simulink在不同风浪环境下进行仿真,验证所提方案有效性和优越性。时域和频域仿真结果表明,与传统比例积分控制方案相比,所提方案对稳定风力机系统输出功率、抑制浮式平台运动及减少塔基载荷具有更好的控制效果。

基于无模型自适应控制的半潜式平台运动性能研究

南海海域油气资源极其丰富,半潜式平台在该海域工作时常常面临着系泊失效这一重大危险情况。该研究以一艘装配有悬链式系泊系统和DP-3动力定位系统的半潜式平台为研究对象,利用AQWA软件开展系泊失效前后半潜式平台运动性能研究。同时,借助于AQWA软件二次开发功能,将无模型自适应控制作为动力定位系统控制理论,以研究半潜式平台系泊失效后运动性能恢复。数值仿真模拟结果表明,采用无模型自适应控制作为动力定位系统控制理论的半潜式平台能很好地恢复系泊失效后的运动性能,有效地减小系泊失效带来的危害;基于偏格式动态线性化和全格式动态线性化的无模型自适应控制比基于紧格式动态线性化的无模型自适应控制能让半潜式平台更快地恢复运动性能。

基于创新能力培养的自动化类专业实践教学探索

提升学生的创新能力和综合工程实践能力,构建高水平的创新实训平台是必不可缺的条件。结合行业背景和地方院校的自动化类专业特色,以具体的可编程逻辑控制器(programmable logic controller,PLC)三轴运动控制实训平台构建为例,按照标准工业自动化产品设计流程,从平台的硬件构建到软件设计,从基本功能实现到创新型功能设计,每一个环节都需要学生将所学课程知识充分理解且综合运用方能实现。该实训平台的构建可有效促进学生的实践能力和创新能力整体水平的提高,适应当今我国社会对复合型应用型专业人才培养的需求。

基于气体静压运动平台的自抗扰控制仿真分析与实验研究

为了进一步提高气体静压运动平台的稳定性以及抗干扰性能,针对气体静压运动平台自身存在的扰动对其控制算法进行研究。文章提出了一种PD控制与线性扩张状态观测器相结合的自抗扰控制算法,在Matlab/Simulink中搭建了控制模型进行仿真分析,并搭建平台进行实验验证。利用该算法解决了传统PID控制算法在气体静压运动平台存在的扰动问题。结果表明:相比于传统PID控制算法,自抗扰控制算法能够有效减小跟踪误差,降低超调,并且提高了气体静压运动平台的抗干扰性能。

高速重载大行程运动升降平台设计及实现

[目的]为满足恶劣海况下舰船的大幅运动模拟需求,开展高速、重载、大行程运动升降平台的研发工作。[方法]针对运动平台的重载、高速及变参数特点,基于Adams仿真平台对采用重量平衡、4钢缆同步伺服驱动的高速升降平台进行动力学仿真分析,提出一种基于模糊PID控制的多电机同步驱动控制系统,并基于控制特性相似原理研制了1∶14的缩比高速升降平台。[结果]通过平台的响应特性试验,验证了控制系统具有同步性强、控制精度高的优点,运动平台可以良好地模拟恶劣海况下舰船的升沉运动。[结论]所设计的重量平衡、4钢缆同步伺服驱动的高速升降平台可填补舰船大幅升沉运动模拟领域的空白,并对类似运动模拟器的研发具有参考意义。

面向多轴运动控制的EtherCAT主站设计与实时性优化

针对传统现场总线在多轴运动控制中存在带宽低、实时性不强、同步性能差的问题,提出了基于IgH EtherCAT Master开源软件框架和嵌入式硬件平台的EtherCAT主站实现方案。在以AM64x Sitara处理器为核心的硬件平台上,构建基于Xenomai实时内核的Linux实时操作系统,移植IgH主站框架,实现了高性能EtherCAT主站,并对EtherCAT总线的配置过程进行阐述,开发出主站应用程序,提出主站进程独占CPU和优化网卡驱动的方式对主站进行实时性能优化。最后通过六轴伺服控制平台进行实验验证,对主站发送的周期性EtherCAT数据帧进行抓包分析。实验结果表明:优化后的主站在500μs的高速通信周期下,最大抖动控制在20μs以内,均值抖动控制在1μs以内,能够满足高精度多轴运动控制的要求。

基于指数增益迭代学习三轴运动平台轮廓控制

为了得到三轴运动平台精确的轮廓误差估计值,提出了一种基于指数增益型迭代学习的轮廓控制方法。以永磁直线同步电机驱动的三轴运动平台为研究对象,建立三轴运动平台的数学模型,采用泰勒扩展轮廓误差估计法对轮廓误差进行估计,并设计了基于指数增益的PD型迭代学习控制器。采用交叉耦合控制策略,选取按比例的分配方式将轮廓误差补偿到原始参考轮廓上。仿真结果表明,针对给定马鞍形和心形曲线采用指数增益迭代学习比传统迭代学习控制的轮廓误差最大值以及均方差值均有所减小,可证明该方法能够有效减小系统轮廓误差,提升轮廓控制精度。

Design of computer vision assisted machine learning based controller for the Stewart platform to track spatial objects

The present work aims to develop an object tracking controller for the Stewart platform using a computer vision-assisted machine learning-based approach.This research is divided into two modules.The first module focuses on the design of a motion controller for the Physik Instrumente(PI)-based Stewart platform.In contrast,the second module deals with the development of a machine-learning-based spatial object tracking algorithm by collecting information from the Zed 2 stereo vision system.Presently,simple feed-forward neural networks(NN)are used to predict the orientation of the top table of the platform.While training,the x,y,and z coordinates of the three-dimensional(3D)object,extracted from images,are used as the input to the NN.In contrast,the orientation information of the platform(that is,rotation about the x,y,and z-axes)is considered as the output from the network.The orientation information obtained from the network is fed to the inverse kinematics-based motion controller(module 1)to move the platform while tracking the object.After training,the optimised NN is used to track the continuously moving 3D object.The experimental results show that the developed NN-based controller has successfully tracked the moving spatial object with reasonably good accuracy.

基于PLC的运动控制实训平台设计

文章针对运动控制技术实训平台缺乏具体的应用场景导致无法直观地展示出运动控制技术的应用问题,提出了以YL239A实训平台为载体的运动控制技术实训升级改造的新方案,并通过试验完成了运动控制技术在平台上的直观展示,从而达到了学生运动控制技术应用实践能力提高的目的。

Road vehicle-induced vibration control of microelectronics facilities

A hybrid control platform is investigated in this paper to mitigate microvibrations to a group of vibration-sensitive equipment installed in a microelectronics facility subject to nearby road vehicle-induced horizontal and vertical ground motions. The hybrid control platform, on which microelectronics equipment is installed, is mounted on a building floor through a series of passive mounts and controlled by hydraulic actuators in both horizontal and vertical directions. The control platform is an elastic body with significant bending modes of vibration, and a sub-optimal control algorithm is used to manipulate the hydraulic actuators with actuator dynamics included. The finite element model and the equations of motion of the coupled platform-building system are then established in the absolute coordinate to facilitate the feedback control and performance evaluation of the platform. The horizontal and vertical ground vibrations at the base of the building induced by nearby moving road vehicles are assumed to be stationary random processes. A typical three-story microelectronics building is selected as a case study. The case study shows that the vertical vibration of the microelectronics building is higher than the horizontal. The use of a hybrid control platform can effectively reduce both horizontal and vertical microvibrations of the microelectronics equipment to the level which satisfies the stringent microscale velocity requirement specified in the Bolt Beranek & Newman (BBN) criteria.

Implementation of Mooring Automatic Positioning System for Deepwater Semi-Submersible Platform Based on Dual-Stage Actuator

The automatic positioning control of mooring system for deepwater semi-submersible platform has become a key issue in the research and development field of deep-sea resources. The Dual- Stage Actuator (DSA) proposed in this paper can replace the single actuator to achieve the high speed and high precision positioning by cooperative control. The relative model and control algorithm of motion trajectory (CAMT) are designed and validated, which proves that the method proposed in this paper is effective.

工业机器人运动控制实训设计与实践

实训课是应用和巩固所学专业知识的一项重要环节,是培养学生能力和技能的一个重要手段。前期的实训课教学内容单一,形式单调,平台不足,导致学生实训效果不佳。针对这些问题,教研室成员针对机器人工程方向人才培养目标,从丰富实训内容、开发线上教学平台,采用线上线下结合的教学形式、整合虚拟和实物实训平台等方面对机器人运动控制实训课进行课程设计与实践。实践证明,之后的实训课更能激发学生的求知欲望,促进学生形成持久的学习兴趣,学生实训成果质量显著提升。

漂浮式风电机组无模型自适应控制

针对漂浮式风电机组叶片载荷、功率及浮式基础振动耦合问题,以尾缘襟翼偏角为输入,以叶根挥舞弯矩,电功率,浮式基础纵摇、艏摇为输出,设计无模型自适应控制系统。同时,将无模型自适应控制与漂浮式风电机组的基准主控系统通过滤波进行频率解耦。在改进FAST的含尾缘襟翼的气弹-伺服仿真平台中进行验证,结果表明所设计的无模型自适应控制系统在不牺牲功率波动的条件下,能够降低叶片疲劳载荷和基础振动。此外,交叉小波分析结果表明,尾缘襟翼控制量的引入削弱了漂浮式风电系统固有的气弹同步相关性,减少了入流风作用在风轮上的能量。

漂浮式风机运动抑制方法综述

通过可靠可控的技术手段,实现浮式风机系统支撑平台的运动抑制,对保障浮式风机的安全性与可靠性具有重要意义。综述各类主要浮式风机运动抑制方法与技术,介绍各种方法的基本原理、技术特点、研究现状和应用情况,以期为相关领域研究人员提供技术参考和研究思路。

无人艇工程控制课程实践教学平台开发

针对在教学环节中存在的问题,利用计算机技术和工业软件开发无人艇工程控制课程实践教学平台。该平台可进行无人水面艇(Unmanned Surface Vessel,USV)建模及运动轨迹控制。针对USV物理参数的不确定性,根据运动学和动力学模型设计控制器,分析控制器参数对USV运动性能的影响规律。无人艇工程控制课程实践教学平台的建设应用可提升学生对USV的运动操控、故障判断及维护保养能力。