AGV车转向总承设计
AGV车转向总承设计,AGV,转向,设计
山 东 轻 工 业 学 院
中英文翻译
院系名称 机械工程学院
学生姓名 孙昌荣
专业班级 机械设计制造及其自动化08-4
指导教师 范维华
二○一二 年 四 月 二十 日
Aluminum multi-degreeof freedom manipulator Design and Implementation
Mechanical hand, is also called from begins, auto hand can imitate the manpower and arm's certain holding function, with by presses the fixed routine to capture, the transporting thing 'OR' operation tool's automatic operation installment. It may replace person's strenuous labor to realize the production mechanization and the automation, can operate under the hostile environment protects the personal safety, thus widely applies in departments and so on machine manufacture, metallurgy, electron, light industry and atomic energy.
The manipulator is mainly composed of the hand and the motion. The hand is uses for to grasp holds the work piece (or tool) the part, according to is grasped holds the thing shape, the size, the weight, the material and the work request has many kinds of structural styles, like the clamp, the request hold and the adsorption and so on. The motion, causes the hand to complete each kind of rotation (swinging), the migration or the compound motion realizes the stipulation movement, changes is grasped holds the thing position and the posture. Motion's fluctuation, the expansion, revolving and so on independence movement way, is called manipulator's degree-of-freedom. In order to capture in the space the optional position and the position object, must have 6 degrees-of-freedom. The degree-of-freedom is the key parameter which the manipulator designs. The degree-of-freedom are more, manipulator's flexibility is bigger, the versatility is broader, its structure is also more complex. Generally the special-purpose manipulator has 2~3 degrees-of-freedom.
The manipulator's type, may divide into the hydraulic pressure type, the air operated according to the drive type, electromotive type, the mechanical manipulator; May divide into the special-purpose manipulator and the general-purpose manipulator two kinds according to the applicable scope; May divide into the position control and the continuous path according to the path control mode controls the manipulator and so on.
The manipulator usually serves as the engine bed or other machine's add-on component, like on the automatic machine or the automatic production line loading and unloading and the transmission work piece, replaces the cutting tool in the machining center and so on, generally does not have the independent control device. Some operating equipment needs by the person direct control, if uses in the host who the atomic energy department manages the dangerous goods from the type operator also often being called the manipulator.
Robot is a type of mechantronics equipment which synthesizes the last research achievement of engine and precision engine, micro-electronics and computer, automation control and drive, sensor and message dispose and artificial intelligence and so on. With the development of economic and the demand for automation control, robot technology is developed quickly and all types of the robots products are come into being. The practicality use of robot products not only solves the problems which are difficult to operate for human being, but also advances the industrial automation program. At present, the research and development of robot involves several kinds of technology and the robot system configuration is so complex that the cost at large is high which to a certain extent limit the robot abroad use. To development economic practicality and high reliability robot system will be value to robot social application and economy development.
With the rapid progress with the control economy and expanding of the modern cities, the let of sewage is increasing quickly: With the development of modern technology and the enhancement of consciousness about environment reserve, more and more people realized the importance and urgent of sewage disposal. Active bacteria method is an effective technique for sewage disposal,The lacunaris plastic is an effective basement for active bacteria adhesion for sewage disposal. The abundance requirement for lacunaris plastic makes it is a consequent for the plastic producing with automation and high productivity. Therefore, it is very necessary to design a manipulator that can automatically fulfill the plastic holding.
With the analysis of the problems in the design of the plastic holding manipulator and synthesizing the robot research and development condition in recent years, a economic scheme is concluded on the basis of the analysis of mechanical configuration, transform system, drive device and control system and guided by the idea of the characteristic and complex of mechanical configuration, electronic, software and hardware. In this article, the mechanical configuration combines the character of direction coordinate and the arthrosis coordinate which can improve the stability and operation flexibility of the system. The main function of the transmission mechanism is to transmit power to implement department and complete the necessary movement. In this transmission structure, the screw transmission mechanism transmits the rotary motion into linear motion. Worm gear can give vary transmission ratio. Both of the transmission mechanisms have a characteristic of compact structure. The design of drive system often is limited by the environment condition and the factor of cost and technical lever. ''''The step motor can receive digital signal directly and has the ability to response outer environment immediately and has no accumulation error, which often is used in driving system. In this driving system, open-loop control system is composed of stepping motor, which can satisfy the demand not only for control precision but also for the target of economic and practicality. On this basis,the analysis of stepping motor in power calculating and style selecting is also given.
The analysis of kinematics and dynamics for object holding manipulator is given in completing the design of mechanical structure and drive system. Kinematics analysis is the basis of path programming and track control. The positive and reverse analysis of manipulator gives the relationship between manipulator space and drive space in position and speed. The relationship between manipulator’s tip position and arthrosis angles is concluded by coordinate transform method. The geometry method is used in solving inverse kinematics problem and the result will provide theory evidence for control system. The f0unction of dynamics is to get the relationship between the movement and force and the target is to satisfy the demand of real time control. in this chamfer, Newton-Euripides method is used in analysis dynamic problem of七he cleaning robot and the arthrosis force and torque are given which provide the foundation for step motor selecting and structure dynamic optimal ting.
Control system is the key and core part of the object holding manipulator system design which will direct effect the reliability and practicality of the robot system in the division of configuration and control function and also will effect or limit the development cost and cycle. With the demand of the PCL-839 card, the PC computer which has a. tight structure and is easy to be extended is used as the principal computer cell and takes the function of system initialization, data operation and dispose, step motor drive and error diagnose and so on. A t the same time, the configuration structure features, task principles and the position function with high precision of the control card PCL-839 are analyzed. Hardware is the matter foundation of the control. System and the software is the spirit of the control system. The target of the software is to combine all the parts in optimizing style and to improve the efficiency and reliability of the control system. The software design of the object holding manipulator control system is divided into several blocks such as system initialization block, data process block and error station detect and dispose model and so on. PCL-839 card can solve the communication between the main computer and the control cells and take the measure of reducing the influence of the outer signal to the control system.
The start and stop frequency of the step motor is far lower than the maximum running frequency. In order to improve the efficiency of the step motor, the increase and decrease of the speed is must considered when the step motor running in high speed and start or stop with great acceleration. The increase and decrease of the motor’s speed can be controlled by the pulse frequency sent to the step motor drive with a rational method. This can be implemented either by hardware or by software. A step motor shift control method is proposed, which is simple to calculate, easy to realize and the theory means is straightforward. The motor'''' s acceleration can fit the torque-frequency curve properly with this method. And the amount of calculation load is less than the linear acceleration shift control method and the method which is based on the exponential rule to change speed. The method is tested by experiment.
A t last, the research content and the achievement are sum up and the problems and shortages in main the content are also listed. The development and application of robot in the future is expected.
多自由度铝合金机械手的设计与实现
能模仿人手和臂的某些动作功能,用以按固定程序抓取、搬运物件或操作工具的自动操作装置。它可代替人的繁重劳动以实现生产的机械化和自动化,能在有害环境下操作以保护人身安全,因而广泛应用于机械制造、冶金、电子、轻工和原子能等部门。
机械手主要由手部和运动机构组成。手部是用来抓持工件(或工具)的部件,根据被抓持物件的形状、尺寸、重量、材料和作业要求而有多种结构形式,如夹持型、托持型和吸附型等。运动机构,使手部完成各种转动(摆动)、移动或复合运动来实现规定的动作,改变被抓持物件的位置和姿势。运动机构的升降、伸缩、旋转等独立运动方式,称为机械手的自由度 。为了抓取空间中任意位置和方位的物体,需有6个自由度。自由度是机 械手设计的关 键参数。自由 度越多,机械手的灵活性越大,通用性越广,其结构也越复杂。一般专用机械手有2~3个自由度。
机械手的种类,按驱动方式可分为液压式、气动式、电动式、机械式机械手;按适用范围可分为专用机械手和通用机械手两种;按运动轨迹控制方式可分为点位控制和连续轨迹控制机械手等。
机械手通常用作机床或其他机器的附加装置,如在自动机床或自动生产线上装卸和传递工件,在加工中心中更换刀具等,一般没有独立的控制装置。有些操作装置需要由人直接操纵,如用于原子能部门操持危险物品的主从式操作手也常称为机械手。
机器人是典型的机电一体化装置,它综合运用了机械与精密机械、微电子与计算机、自动控制与驱动、传感器与信息处理以及人工智能等多学科的最新研究成果,随着经济的发展和各行各业对自动化程度要求的提高,机器人技术得到了迅速发展,出现了各种各样的机器人产品。机器人产品的实用化,既解决了许多单靠人力难以解决的实际问题,又促进了工业自动化的进程。目前,由于机器人的研制和开发涉及多方面的技术,系统结构复杂,开发和研制的成本普遍较高,在某种程度上限制了该项技术的广泛应用,因此,研制经济型、实用化、高可靠性机器人系统具有广泛的社会现实意义和经济价值。
由于我国经济建设和城市化的快速发展,城市污水排放量增长很快,污水处理己经摆在了人们的议事日程上来。随着科学技术的发展和人类知识水平的提高,人们越来越认识到污水处理的重要性和迫切性,科学家和研究人员发现塑料制品在水中是用于污水处理的很有效的污泥菌群的附着体。塑料制品的大量需求,使得塑料制品生产的自动化和高效率要求成为经济发展的必然。
本文结合塑料一次挤出成型机和塑料抓取机械手的研制过程中出现的问题,综述近儿年机器人技术研究和发展的状况,在充分发挥机、电、软、硬件各自特点和优势互补的基础上,对物料抓取机械手整体机械结构、传动系统、驱动装置和控制系统进行了分析和设计,提出了一套经济型设计方案。采用直角坐标和关节坐标相结合的框架式机械结构形式,这种方式能够提高系统的稳定性和操作灵活性。传动装置的作用是将驱动元件的动力传递给机器人机械手相应的执行机构,以实现各种必要的运动,传动方式上采用结构紧凑、传动比大的蜗轮蜗杆传动和将旋转运动转换为直线运动的螺旋传动。机械手驱动系统的设计往往受到作业环境条件的限制,同时也要考虑价格因素的影响以及能够达到的技术水平。由于步进电机能够直接接收数字量,响应速度快而且工作可靠并无累积误差,常用作数字控制系统驱动机构的动力元件,因此,在驱动装置中采用由步进电机构成的开环控制方式,这种方式既能满足控制精度的要求,又能达到经济性、实用化目的,在此基础上,对步进电机的功率计一算及选型问题经行了分析。
在完成机械结构和驱动系统设计的基础上,对物料抓取机械手运动学和动力学进行了分析。运动学分析是路径规划和轨迹控制的基础,对操作臂进行了运动学正、逆问题的分析可以完成操作空间位置和速度向驱动空间的映射,采用齐次坐标变换法得到了操作臂末端位置和姿态随关节夹角之间的变换关系,采用几何法分析了操作臂的逆向运动学方程求解问题,对控制系统设计提供了理论依据。机器人动力学是研究物体的运动和作用力之间的关系的科学,研究的目的是为了满足是实时性控制的需要,本文采用牛顿-欧拉方法对物料抓取机械手动力学进行了分析,计算出了关节力和关节力矩,为步进电机的选型和动力学分析与结构优化提供理论依据。
控制部分是整个物料抓取机械手系统设计关键和核心,它在结构和功能上的划分和实现直接关系到机器人系统的可靠性、实用性,也影响和制约机械手系统的研制成本和开发周期。在控制主机的选用上,采用结构紧凑、扩展功能强和可靠性高的PC工业控制计算机作为主机,配以PCL-839卡主要承担系统功能初始化、数据运算与处理、步进电机驱动以及故障诊断等功能;同时对PCL-839卡的结构特点、功能原理和其高定位功能等给与了分析。硬件是整个控制系统以及极限位置功能赖以存在的物质基础,软件则是计算机控制系统的神经中枢,软件设计的目的是以最优的方式将各部分功能有机的结合起来,使系统具有较高的运行效率和较强的可靠性。在物料抓取机械手软件的设计上,采用的是模块化结构,分为系统初始化模块、数据处理模块和故障状态检测与处理等几部分。主控计算机和各控制单元之间全部由PCL-839卡联系,并且由该卡实现抗干扰等问题,减少外部信号对系统的影响。
步进电机的启停频率远远小于其最高运行频率,为了提高工作效率,需要步进电机高速运行并快速启停时,必须考虑它的升,降速控制问题。电机的升降速控制可以归结为以某种合理的力一式控制发送到步进电机驱动器的脉冲频率,这可由硬件实现,也可由软件方法来实现。本文提出了一种算法简单、易于实现、理论意义明确的步进电机变速控制策略:定时器常量修改变速控制方案。该方法能使步进电机加速度与其力矩——频率曲线较好地拟合,从而提高变速效率。而且它的计算量比线性加速度变速和基于指数规律加速度的变速控制小得多。通过实验证明了该方法的有效性。
最后,对论文主要研究内容和取得的技术成果进行了总结,提出了存在的问题和不足,同时对机器人技术的发展和应用进行了展望。
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