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英文资料文献Load-Haul-DumpI. Literature 1.1 Introduction Within this dissertation the field of control systems and their implementation to existing rim, methodology and the general overview of the conducted research, design and co bots will be examined and finally carried out. This chapter will outline and discuss the constructions of the control systems. 1.2 Project Aim The aim of this project is to investigate suitable control strategies for the maneuvering of a Load-Haul-Dump (LHD) unit within the confines of a mine. Further research is to be done specifically on a tale-operational and fully automated control system to investigate what would be required to implement such a system to a LHD unit. Due to the tale-operational system requiring the use of a camera, the automated system will also utilizes this tool by using machine vision as its guidance system. The core of this project will then be the implementation of these two control systems to an existing scale model of a LHD unit. 1.3 Methodology The following steps are the way in which this project will be undertaken. All of these will be conducted under the supervision of a professional engineer who will assist with guidance and provide some technical information and advice. 1.4 Conclusion This chapter has introduced the project at hand implementing a tele-operatedand automated control system to an already constructed LHD model unit. Discussed in the next chapter is beneficial background information which will form the basis for latter sections of this report. 1.5 LHD Model Analysis Analyses the already constructed LHD model to ascertain how it all operates, as well as the mechanical, electrical and control features. This information was gathered by experimenting with it and testing its boundaries. The following could then be determined: Whether the existing mechanical features, circuitry and programming are appropriate for my project.What equipment, components or programming needs to be re-designed to allow the unit to be tale-operated and auto mated. 1.6 Modeling Review an appropriate modeling technique for the LHD unit, choose appropriate state variables and derive an algebraic equation for the control of the unit. This will be done by researching different modeling methods through databases, libraries and previous engineering related study. Simulation is used to test these, and to verify the unit will act how one would expect it to according to various inputs. This simulation will be conducted using Microsoft Visual Basic 6.0. 1.7 Programming Construct the communication programs for the unit to run tale-operated and automated. This program will also be coded using Microsoft Visual Basic 6.0, and will include functions to do all of the following: Receive the visual from the unit to the computer. Instruct the unit what direction it should go (far tale-operational), or detect the walls of the tunnel and move accordingly (for automated). 1.8 Testing Finally, the LHD unit will be physically tested to ensure it will operate correctly for both of the control strategies. This will be done by putting together a simulated tunnel for the unit to maneuvers its way through without encountering any collisions. 1.9 Conclusion This chapter has introduced the project at hand, implementing a tale-operated and automated control system to an already constructed LHD model unit. IILoad-Haul Dump Units 2.1 Introduction This chapter will review literature to establish the need for a suitable control strategy for the widely used Load-Haul-Dump (LHD) unit. After researching and gathering the relevant background information appropriate for this project, it is then possible to implement these strategies to an actual model LHD unit. 2.2 Load-Haul Dump Units The load-haul-dump (LHD) unit is used extensively in underground mining to perform a variety of tasks within this field. Although their main role is to return and transport the mines ore from the point of cutting to either dumping points, haulage trucks or crushing station (Tyson ). The underground mining environment is extremely dangerous where some LHD accidents have caused major injury and occasional deaths to the operators onboard these vehicles as well as other mining crew. These vehicles must be able to travel through narrow winding tunnels which have high temperatures, dusty and dirty conditions as well as withstanding the occasional collision with the walls of the tunnel. Typical LHD units, as shown in figure 1.1, are either diesel or electric powered, running on four solid rubber tires and no suspension. They are made up of an articulated body with the two section connected by a kingpin hitch that can pivot. This articulated setup uses two hydraulic actuators to provide the steering for the unit which provides excellent curve negotiation within the tight winding tunnels. Figure 1.1: Load-Haul-Dump unitThe two sections of the unit both have a single axle with non steerable wheels, the front section contains the bucket or scoop, and the back section contains the engine. The profile of the vehicle complies with the cross section of the mining tunnels they are used in, this means they are long, low and relatively wide compared to their height (Tyson n.d.). 2.3 Control Strategies A control system implemented onto a LHD unit would be ideal for the dangerous mine environments in which they operate, although would prove to be difficult due to the rough, unpredictable state of the mines. Stents(2001) stated that a semi-automated system would promote features such as increased productivity, reduced operational costs and improved safety. There is a wide range of different control strategies that could be implemented onto a LHD unit. The two main categories of these are either infrastructure assisted guidance or an independent vehicle strategy that required no infrastructure construction or modifying of the tunnels (Billingsley 1997, p3). The advantage of the independent vehicle control strategy is that since no changes need to be made to the physical tunnel of the mine the LHD unit is being used in, the vehicle can be used in any mine at anytime. The four main control strategies that were analyzed and compared regarding the LHD unit were manual operation, remote control, tale-operational and fully automated. 2.3.1 Manual Operation Manual operation is currently the most common strategy used in the mining industry, where a driver is onboard the LHD unit at all times positioned in a closed cabin. The cabin is positioned perpendicular to the direction of travel for viewing where the vehicle is going in the forward and backward direction. The main disadvantage to this operating method is the concern of the drivers safety, driver fatigue and basic human error. The advantage to this method, compared to remote control and tale-operational methods is that the unit can travel much faster through the tunnels as the operator is on board, this is due to remote sensory perception (Robert et al. 2000).2.3.2 Remote Control A remote control vehicle means that the operator is out and distanced from the machine but still in the line of sight of the unit to control it via a remote control transmitter. The advantage to this system is that the operator is located away from the immediate danger the LHD would otherwise put an onboard driver in. Saying this, there is still the risk of injury and accidents due to the line of sight rule and there is still the concern of driver fatigue and human error. The disadvantage to this system is that the driver is not in any type of cabin area and since they must be in line of sight of the vehicle at all times it usually requires them to stand while controlling the unit. Consequently there is still the risk of injury with driver fatigue and human error still a concern.2.3.3 Tele-operated Control A tale-operated control system is similar to a remote controlled system, where the operator is still in full control of the vehicle at all times but there is greater distance between the operator and the device. The operator can be safe and comfortable aboveground controlling the vehicle by an operator interface. This interface consists of two basic components; the vision system and control panel. The main disadvantage to this control system is that the vehicle is not able to be driven as fast as what could be achieved with a driver actually onboard the unit. This is due to the limited remote sensory perception (Robert et al. 2000). 2.3.4 Fully Automated Control An automated system means the operator is still above ground, but he is playing a supervisory role to the system, hence they are still remote from the danger within the mine. There are a number of ways to implement an automated system the most common include machine vision, sensors and receivers, and GPS. These will be covered later. The main advantage to this system is that since the vehicle is capable of autonomous steering throughout the underground tunnels, the LHD unit can travel at a greater speed, hence improving productivity whilst still maintaining a safe environment. 2.5 Machine Vision Machine vision is the acquiring and processing of an image and then the deciphering of information presented in the image for controlling a specific purpose. It uses digital cameras, image processing software and relevant communication between digital input/output devices of the system it is controlling. The key characteristics of any standard machine vision system is a digital camera with a camera interface program which captures the cameras image and converts the image into an array of numbers. This array represents the pixels of the image and the image is then manipulated or analyzed by computer software depending on the application of the system. 2.6 Modeling To successfully design a control system for any type of vehicle it is essential to have a model the can describe the vehicles position, orientation and other important vehicle parameters at any point in time. As stated by Ridley and Corke (2003), for a LHD unit the basic kinematic model is the most appropriate modeling method for the vehicle, although this can be a challenging task due to the unique articulated structure of the unit. 2.7 Conclusion This chapter reviewed literature and established a clear view of the Load-Haul- Dump (LHD) unit, the type of modeling to be conducted and also a brief summation on the control strategies to be implemented to the vehicle. 中文部分： 铲运机1.文献1.1简介 在本论文中，控制系统及其在现有机器上的实施领域将审议并最终执行。本章将概述和讨论研究的目的,方法和普遍概况,和控制系统的建设与设计。1.2项目目标 这个项目的目的是为地下铲运机的机动性探讨适当的控制策略。进一步的研究工作将展开尤其是远程操作系统和完全自动化控制系统，调查在一个铲运机上实施这样一个系统需要什么。由于远程业务系统要求使用照相机，自动系统也将利用此工具，将机器视觉作为指导系统。这个项目的核心将是这两个控制系统在一个现有规模的铲运机模型上的实施。1.3方法 下面的步骤是在本项目将采取的方式。所有步骤将在专业工程师监督协助指导下进行，并由他们提供一些技术资料和意见。相关文献于以下方面： 一个典型的铲运机的主要特征，以及他们需要做什么。 自动化的实施。自动化可以实现什么？自动铲运机对采矿业意味着什么？ 这两个控制策略：远程操作和自动化系统.这些控制策略的优点和缺点是什么？实施这些系统时将用到哪些设备和任务？这是来源于检索数据库，图书馆和其他公共信息。1.4铲运机模型分析 分析已经建成的铲运机模型来查明铲运机是如何操作的，如机械，电气和控制功能。这些资料是靠对它做试验和测试它的边界收集到的。下面可确定： 是否现有的机械特性，电路和编程适合我的项目。 哪些设备，部件或编程需要重新设计才能实现机器的远程操作和自动化。1.5 建模 回顾一下适当的铲运机建模技术，为机器的控制选择适当的状态变量并得出一个代数方程。这项工作通过研究不同的建模方法来实施，其资源来自数据库，图书馆和以往工程相关研究。使用模拟技术测试，并核实该机器直到它能够依照各种输入来采取行动。这种模拟将采用微软的Visual Basic 6.0。1.6 程序设计为铲运机构建通讯方案用来运行远程操作和自动化。这个程序也被Microsoft Visual Basic 6.0编码使用，并将包括以下所有功能： 从装置接收视觉信号并发送到计算机。 指示机器应该朝什么方向走（最远距离操作），或者检测隧道的墙壁和相应地移动（自动化）1.7测试 最后，铲运机将被检验，以确保它能在两种控制策略下正常运行。这项测试将铲运机放入一个模拟隧道中通过其演习行走而不遇到任何碰撞。1.8结论 本章介绍了手头的项目，实施远程操作和自动化控制系统，一个已经建成铲运机模型。2. 地下铲运机2.1简介 本章文献，为广泛使用的铲运机建立一个合适的控制策略。经过对这个项目的研究和有关背景资料的收集，则可能实施以一个实际的模型铲运机为单位的策略。 2.2铲运机 铲运机广泛用于矿山井下这个领域，执行多种任务。尽管他们的主要作用是往返和运输矿物于挖掘点和倾倒点之间，像托运卡车。地下开采的环境是极其危险的地方，有些铲运机事故会造成那些机器操者以及其他采矿人员的重伤，严重的会死亡。这些车辆必须能够穿过狭窄蜿蜒的隧道，隧道里温度很高，很脏，有很多灰尘，以及抵御和隧道壁的偶尔相撞偶尔。 . 典型铲运机，如图1.1所示，用柴油或电力发动，支撑在四个实心橡胶轮胎上，没有间隙。它们是由一个铰接式机体组成，由一个主销栓连接两个部分。这种铰接式格局使用两个液压系统，为机器在曲折狭窄的隧道中转向提供良好的督导。该机器的两节都有一个装有不可操纵轮的轴，前面部分包铲斗或铲头，和后面的部分包含引擎。机器的外形必须符合它们工作的巷道，这意味着机器的外形较长，较宽，较矮。 2.3控制策略 一个控制系统安装到铲运机上是理想的，由于其工作在危险的煤矿环境中。但这是非常困难的，由于粗糙的，不可预知的环境。斯滕茨声称半自动化系统将促进生产力，如增加产量，降低运营成本，提高了安全性。在铲运机上有许多不同的控制策略可以实施。这些当中有两个主要的类别，分别是基础设施辅助和独立的整车战略，没有对基础设施或隧道修改上的要求。独立控制车辆的优势，是不需要对铲运机工作的隧道作出任何改变，车辆可以用在任何时候运行在任何矿井。对铲运机的四个主要控制策略做了分析和比较，分别是人工操作，远程控制，远程操作和全自动化。 2.3.1手动操作 手动操作是当前用于采矿业最常见的手段，坐在封闭仓内的司机可以随时定位。机舱的位置于运行方向垂直，用来观察该车辆前进和后退的方向。这种操作方法的主要缺点是关系到司机的安全，驾驶疲劳和基本人为错误。与远程控制和远程操作的方法相比，该方法的优势是该机器可以更快在隧道行走，2.3.2远程控制 远程控制车辆是指操作者远离了机器，但该机器仍然在他的视线范围内，通过一个遥控话筒来控制机器。该系统的优势，这是操作者位于远离及时危险的地方，而不是直接在铲运机上操作。虽然这么说，但仍然存在伤害和意外事故的风险，因为铲运机要在视线范围内运作，还事关司机的驾驶疲劳和人为错误。该系统的缺点是，操作者没有在机舱操作，而铲运机在工作过程中必须一直在他们的视线范围内，这要求他们在操作过程中要一直站着。因此仍然有受伤的风险，也关系到司机疲劳损伤和人为错误。 2.3.3远程操作控制 遥操作控制系统是一个类似远程控制的系统，其中操作者在铲运机工作室完全掌控它，但二者之间有一段很长的距离。舒适的在地面通过操作界面来控制车辆。这个接口由两个基本组成部分：视觉系统和控制面板。主要缺点是，这种系统控制的车辆不能像有司机在车上操作运行时行走的那么快。这是由于有远程感官知觉的局限（罗伯特等人。2000年）。 2.3.4全自动控制 自动化系统是指操作者仍位于地面，但他担任着一个监督该系统的角色，因此他们依然远离危险。有很多方法可以实现自动化系统，最常用的包括机器视觉，传感器和接收器和全球定位系统，将来也会用到这些。该控制系统的主要优点是，由于车辆转在整个地下隧道中有能力自主监督，铲运机可以以更快的速度运行，因而提高生产力的同时还保持一个安全的环境。 2.4机器视觉 机器视觉是靠获取影像和对它进行处理，然后破译图像中的信息达到对机器控制的目的。它使用所控制的系统中的数码相机，图像处理软件和有关数字通信设备。任意规格的机器视觉系统的主要特征是数码相机的接口方案，其中一个相机捕捉到图像并把该图像转换为数字序列。这个序列代表图像的像素，然后在系统运行时用电脑操作和分析这个图像。 2.5建模 要成功的设计一个任意类型的车辆控制系统，有必要拥有一个能在任意时间内描述车辆位置，方向和其他重要的车辆参数的模型。正如里德利和科克所说，对一个铲运机来说，基本运动模型是最合适的车辆造型方式，尽管这是一项艰巨的任务，因为其独特的铰接式结构。 2.6 结论 本章回顾文献，并建立了对铲运机明确的看法，并在建模和控制策略的实施上做一个简短的总结。
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