部分断面掘进机的自动断面控制.doc

部分断面掘进机的自动断面控制Automatic Profile Control of a Roadheader Olaf Katowsk 墨伯娜公路隧道掘进时，使用了两台装有连续自动测量断面控制系统的部分断面掘进机。操作人员通过监视器监控给定断面的切削过程。 在隧道施工时，测量是最重要的：必须确定隧道的起点和终点，在施工过程中必须不断地进行监控，以确保按设计的路线掘进。 相当长的一段时间以来，隧道掘进机(TMB)使用合适的测量系统进行连续导向。最新一代的测量系统采用了同样的仪器，也可用于轴线的定线和检测已挖掘的隧道段。这些仪器（准确测量角度和距离的经纬仪）早已自动化，因此能用于全自动过程。 瑞士赫尔伯格的莱卡公司在自动经纬仪的基础上开发出经纬仪测量系统，该测量系统按照极座标测量系统发挥作用，也可用于监视和控制正在施工的机械。测量仪器自动地测量机械设备上待测点与经纬仪测点的角度和距离，该系统迅速进行所需要的计算。当设备移动到新位置时，搜寻方式自动确定设备的待测点，然后进行测量。在修建澳大利亚墨尔本城市连接项目的隧道时，在三井制造的S300部分断面掘进机上采用了两套这种系统。 每台部分断面掘进机的操作人员除控制设备行进外，还要控制刀盘的定位和进尺。与激光标记相比，以往是凭肉眼检查刀盘位置。根据当时的情况（如灰尘影响观测），激光技术并不总是容易掌握。这样，掘进断面的质量有时与要求相差甚远，这种情况也适用于精确度和表面。另外，由于种种理由，部分断面掘进机常常用于超挖。 采用自动经纬仪测量系统“引导”部分断面掘进机，能以很高的精确度和表面质量切削断面。这与无联机系统支持的切削相比，大大地提高了所能达到的精确度。因为在切削过程中，设备的位置和方位不变，所以当设备移至新的掘进位置时，首先需要进行测量。 在切削过程中，只有刀臂和刀盘移动，这样设备已确定的位置保持不变。尽管如此，在切削过程中，用经纬仪连续地监控设备，以便能够立即发现可能出现的无意造成的位移。测量过程 莱卡自动视距仪TCA1800直接固定在设备尾部位于隧道顶部下面的托架上。所谓的自由定位系统确定测量仪器在隧道坐标系统中的位置和方位。然后瞄准设备上四个待测点中的一个，视距仪自动连接到同步模式，用这个模式可以在测量过程中自动跟踪设备。图1莱卡TCA1800自动经纬仪自动搜寻待测点，确定后进行测量 当需要时，操作人员按下按钮就可获得设备位置和方位的信息，通过设备和测量仪器之间的无线电信号开始测量设备上的待测点。与设备的方位无关，经纬仪能自动地找到设备各待测点，并进行测量，然后，计算设备主要测点的位置以及设备在隧道坐标系统中的方位。接着，用集成线性编码器记录液压缸的伸出长度，用此计算刀盘的位置。储存在计算机内的设备几何数据用于此目的。设备操作人员能在监视器上不断地观察到刀盘在隧道断面所处的位置和其它的信息（轴线、断面类型、时间、在轴线上的位置和偏移）。图2 标有待测点的设备(设备点) 切削过程基本上是由操作人员通过监视器进行控制。该系统控制切削不超出给定断面。对于任何超出给定断面的切削，继电器断开使切削停止。操作人员只能将刀盘从断面拉回，却不能使刀盘前进。如果需要，停止切削可以由相应的软件开关进行控制。 另外，该系统还存储了由操作人员依据点密度确定的切削断面，这些数据以后可以用于显示切削断面。图3 设备监视器上的显示 输入有关工程项目的数据，可大体上得到轴线和给定的断面。一般，轴线保持不变。为了适应不同的地质条件，必须当场进行评估，也可能必须改变断面。这就意味着，虽然保留事先确定的断面类型，但是为了抵消松动岩石产生的崩落效应，有可能必须缩小断面宽度。 通过标记适当的待测点和画出相应的连接线确定轴线，并将这些信息储存于系统计算机里。也根据预测的岩石类型和掘进的量预先确定断面。将这些信息连同各个断面的形状和公里标（从/到）存储于数据库中。现场需作的任何改动将直接在系统计算机上进行。结果和前景 对于要求的设备定位的精确度达到了不超过1厘米。对于隧道施工人员来说，更重要的是精确度，要能够按此精确度切削断面。力求断面切削的精确度达到3厘米。借助经纬仪控制能够达到这个值，但主要受所切削岩石类型的影响。在说明精确度时，也必须考虑所用设备的性能。 已完成了对装有两套安装系统的上述测量系统的试验。这种测量系统也适用于其它制造厂家的部分断面掘进机以及引导钻孔车。在这方面，这种系统至少使钻孔车定位最优化。在安装这些系统时，要考虑用户的特殊要求。 目前，对这种系统作进一步的开发，以便使停走技术能投入使用，应用时要求连续监控。这主要涉及建设范围大的工程项目，如修建公路和铁路，或机场跑道。 Olaf Katowski 特许工程师，莱卡公司系统工程商务总经理，瑞士 HeerbruggBACK HOMEFor the heading of a Melbourne road tunnel, 2 roadheaders were equipped with automatic, continuously measuring profile control systems.The cutting process for the desired profile is monitored by the machine operator via a monitor.Surveying is of paramount importance during the construction of a tunnel: the starting and finishing points of the tunnel must be determined and during the construction phase, continuous monitoring is essential to ensure that the drive is following the stipulated route.Tunnel boring machines (TBMs) e.g. have been continuously guided for quite some time now thanks to suitable measuring systems. The latest generation of these measuring systems makes use of the same instruments, which are also employed for aligning axes and for inspecting the tunnel sections that have already been created. These instruments (theodolites for the precise measurement of angles and distances) have been motorised for some length of time and can accordingly be applied for fully-automatic processes.On the basis of its automatic theodoliets, the Leica AG, Heerbrugg/Switzerland, has developed theodolite measuring systems, which function in accordance with the polar measurement system and which in the interim, are also used for monitoring and controlling of machines on the construction sector. The measuring instrument automatically determines the angles and distances to each of the target points marked on the machine related to the theodolite station and the system subsequently carries out the required calcul-ations immediately. When the machine moves to a new position, the search mode ensures that the system automatically relocates the machine points and re-measures. Two of these systems are in use with S300 roadhe-aders made by Mitsui Miike for constructing the tunnels of the City Link Project in Melbo-urne, Australia. The operator of each roadheader controls the machine guidance as well as the positioning and advancing of the cutter head. Formerly, the cutter head position was checked visually with respect to laser markings. Depending on the local circumstances (e.g. impairment of vision as a result of dust development) the laser technique was not always easy to apply. This sometimes led to the quality of the cut profile leaving much to be desired. This applied both to the accuracy as well as the surface. In addition, for various reasons, it is often used to cut excessive profile.The application of an automatic theodolite measuring system for the guidance of the roadheader facilitates outstanding accuracy and surface quality during the cutting of the profile. Compared with cutting without the support of an on-line system, the accuracies that can be attained are considerably enha-nced. As the position and alignment of the machine do not change during the cutting procedure, measurements are first required when the machine is shifted.Only the cutter arm and the cutter head move so that the machines previously determined position is maintained. Nonetheless, during the cutting procedure, the theodolite contin-uously monitors the machine in order to ensure that any undesired displacements are identified right away.The Measuring ProcessThe automatic Leica-Tachymeter TCA 1800 is mounted on a bracket directly under the tunnel ridge at the rear of the machine. So-called free stationing enables the position and alignment of the measuring instrument to be determined in relation to the tunnel co-ordinate system. Subsequently, one of the 4 machine points is then targeted and the totalstation automatically switches to lock-in mode, through which it can track the machine during measuring.When necessary, the machine operator obt-ains information about the position and alignment of the machine by pressing a button. Radio signals between the machine and the measuring instrument initiate the measure-ments of the machine points. Regardless of the alignment of the machine, the theodolite automatically locates the individual machine points and carries out the measurement. Afterwards, the position of the main machine point as well as the machine alignment within the tunnel co-ordinate system are worked out. Furthermore, the extension movements of the hydraulic cylinders are registered by the inte-grated linear encoders and utilised to calc-ulate the position of the cutter head. The geo-metrical date of the machine stored in the computer are applied for this purpose. The machine operator is constantly provided with the cutter heads current position vis-a-vis the tunnel profile along with other date (axis, type of profile, time, position on the axis, offsets) on a monitor. The cutting procedure is by and large controlled by the operator via this monitor. The system ensures that cutting in excess of the desired profile is excluded. Any attempt to cut beyond the desired profile is blocked by the opening of a relay. The operator can then only withdraw the cutter head from the profile, he cannot progress any further. If need be, the blocking mode can be overri-dden by corresponding software.In addition, the system stores the cut profile in accordance with the point density defined by the operator. These data can subsequently be made use of to present the cut profile.The axis and desired profiles are obtained largely by incorporating the relevant project data. By and large, the axis is retained without alteration. In order to accommodate changing geoloical condi-tions,it must be possible to change the profile on the spot at short notice. This means in practice that the type of profile as originally defined is retained but possibly the width of profile may have to be reduced in order to counteract the effects of breakout resulting from the presence of loose rock.The axis itself is defined by marking appro-priate points and establishing of correspon-ding links. The system computer stores this information. The profiles are also defined in advance in accordance with the anticipated types of rock and the number of headings, They are stored in the database along with their individual designs and their chainage (from/to). Any modification that is required on site introduced directly into the systemcomputer. 图4 标有参数的典型断面 Results and Outlook The required accuracy for ascertaining the machine position of1 cm is attained. The accuracy with which the profile can be cut is even more important for the tunneller. The accuracy strived for here amounts to 3 cm. This goal can be arrived at thanks to theo-dolite guidance but the