Guidance Navigation Limited - the use of multibeam laser sensing to provide 3D environment analysis for a position and attitude reference sensor for offshore dynamic vessel or other control systems

许多近海船舶使用基于GPS的动态定位（DP）系统来辅助导航和控制。新的位置测量设备（PME）船级社规则要求在某些操作中使用三个独立的PME。独立性的要求是基于共同的失效模式，所以多个GPS不能被认为是独立的。目前，与海上设施相关的船舶近距离定位是通过2D激光或雷达定位系统与船舶DP系统一起工作，这些系统提供x和y坐标。现有设备依赖于专门的目标，例如固定海上平台上的激光棱镜集群，在操作开始之前被正确部署和维护，以识别相对位置，见图1。为了使现有系统正确可靠地运行，需要仔细定位目标。在作业开始前的关键时期，由于外部影响，例如其他船只遮挡了现有设备所要求的视线，或其他移动反射装置的错误反射，任何问题往往会在作业期间变得明显。图2展示了一个典型的系统。参见来自太古集团（最大的DP船队运营商之一）的问题确认。船舶定位也受到与传感器位置相关的目标可见性的限制，从而限制了进近角度。这可能会阻碍在恶劣天气条件下的操作，也经常导致船只排队进入，增加了大量的操作成本。目标的位置受可用体系结构的限制，可能不是最佳位置。与这些目标相关的设置和维护成本很高。在平台上定位反射器的要求也增加了安装、维护和责任方面的商业复杂性。在无人装置上定位传感器是一个特别的挑战。现有系统提供二维平面位置视图，不能识别高程视场中的潜在异常。该项目旨在开发一种多光束激光传感系统，该系统可以从激光图像（如图3所示）中提供导出的3d位置，并集成到DP系统中，从而实现无目标的海上作业。它将增加操作的灵活性，例如进场方向、天气窗口，从而使业主获得更高的租赁率和利用率。它能够识别x、y和z区域的异常情况，降低碰撞风险和后续成本，并提高安全性。定位能力是自包含在船舶内。对于海上建筑工地等动态海上设施来说，这种灵活性也很有趣。它还可以与其他船舶控制系统接口，如稳定或起重机控制。

Many offshore vessels use GPS based Dynamic Positioning (DP) systems to assist navigationand control. New position measurement equipment (PME) classification society rules for DPvessels require that three independent PME are used during certain operations. Therequirement for independence is based on common failure modes, so multiple GPS cannot becounted as independent. Currently close positioning of vessels in relation to offshoreinstallations is undertaken with 2D laser or radar positioning systems working in conjunctionwith the vessels DP system, these provide x & y coordinates. Existing equipment relies onspecialised targets, e.g. laser prism clusters on fixed offshore platforms, being correctlydeployed and maintained prior to operational commencement to enable the identification ofthe relative location, see Fig 1. The targets need to be carefully positioned in order for existingsystems to function correctly and reliably. Any problems tend to become apparent during thecritical period before operations commence and occasionally during operations, due toexternal influences e.g. other vessels obscuring the line of sight required by existingequipment or false reflections from other mobile reflective devices. Fig 2 illustrates a typicalsystem. See confirmation of issues from Swire Group one of the largest DP fleet operators inApp A. Vessel positioning is also limited by the visibility of the targets in relation to thesensor location, constraining the angle of approach. This may hamper operational access inadverse weather conditions and also often leads to vessels queueing for access, addingsignificant operational costs. The location of targets is limited by available architecture andmay not be optimally sited. There are significant set up and maintenance costs associated withthese targets. The requirement for locating the reflectors on the platform also adds commercialcomplexities, in terms of installing, maintaining and liability. Locating the sensors is aparticular challenge on unmanned installations. Existing systems provide a 2D planar view ofthe position and do not identify potential anomalies in the elevation field of view.The project aims to develop a multibeam laser sensing system that provides the derived 3Dposition from the laser image (see Fig 3 for example) for integration into the DP system toenable offshore operation without targets. It will increase operational flexibility, e.g. directionof approach, weather window, consequently allowing the owners to achieve higher lease andutilisation rates. It enables the identification of anomalies in x,y and z fields reducing the riskof collisions and subsequent costs, and improving safety. The positioning capability is selfcontainedwithin the vessel. The flexibility is additionally interesting for more dynamicoffshore installations such as offshore construction sites. It could also interface with othervessel control systems such as stability or crane control.