An Autonomous GNSS/MEMS-Based INS Integrated System for Unmanned Mapping Operations

近年来，小型无人水面飞行器(USV)和无人驾驶飞行器(UAV)的发展为开发可用于许多关键应用的低成本系统打开了大门。这些领域包括海底和地形测绘、灾害监测、搜救、公共安全、精准农业、露天采矿、道路检查等。然而，在这些关键应用中使用无人机和无人机通常需要连续的高精度定位和姿态信息。不幸的是，现有的定位和姿态系统要么非常昂贵和笨重，要么非常不准确。前一种系统通常集成了全球定位系统(GPS)和高端惯性传感器，由于重量和成本的原因，不能用于小型无人测绘系统。另一方面，后者往往依赖低成本的GPS系统，无法提供准确的定位和姿态信息，并且容易受到信号阻塞和干扰，特别是在城市地区。 为了克服上述局限性，本研究将开发一种低成本的自主定位定位系统。该系统集成了多星座全球导航卫星系统(GNSS)和新兴的基于微电子机械系统(MEMS)的惯性传感器。虽然是自主的，但拟议的系统将建立在申请者研究小组目前正在开发的精确点定位(PPP)概念之上，该概念提供的精度水平可与复杂差分实时运动学技术(即厘米到分米水平)相媲美。此外，拟议的系统将使用在原始测量领域进行的紧耦合机械化来开发。因此，即使卫星数量减少到四颗以下，GNSS信号仍然可以使用，而单独使用GPS系统则不是这样。此外，MEMS传感器相对独立于环境，体积小，价格便宜，重量轻，功耗非常低。这意味着，拟议的系统除了满足所需的准确性、可靠性和可用性外，还将是廉价、小巧和灵活的。因此，与现有系统相比，它具有显著的优势。 拟议研究项目的技术成果包括基于GNSS/MEMS的自主、低成本集成惯性系统的算法和估计方法，以及支持商业下一代小型无人机和无人机测绘作业的软件和原型系统。开发的软件可以作为独立的产品使用，也可以与其他系统集成，例如车载成像系统。这反过来可能导致一种智能系统的开发，该系统可以使整个无人机或无人机任务自动化。这样的创新系统在其他地方还没有开发出来。

The evolution of small unmanned surface vehicles (USVs) and unmanned aerial vehicles (UAVs) in recent years has opened the door for the development of low-cost systems that can be used for many critical applications. These include seafloor and topographic mapping, disaster monitoring, search and rescue, public safety, precision agriculture, open-pit mining, road inspection, and others. The use of USVs and UAVs in these critical applications, however, often requires continuous high accuracy positioning and attitude information. Unfortunately, existing positioning and attitude systems are either very expensive and bulky or very inaccurate. The former system types, which typically integrate differential global positioning system (GPS) and high-end inertial sensors, cannot be used on small unmanned mapping systems due to their weight and cost. The latter types, on the other hand, often rely on low-cost GPS systems, which cannot provide accurate positioning and attitude information and are susceptible to signal blockage and interference, especially in urban areas. To overcome the above limitations, a low-cost autonomous positioning and orientation system will be developed in this research. The proposed system integrates multi-constellation global navigation satellite systems (GNSS) and emerging micro-electro-mechanical system (MEMS)-based inertial sensors. Although autonomous, the proposed system will be built on the concept of precise point positioning (PPP) currently being developed by the applicant’s research group, which provides accuracy level comparable to that of complex differential real-time kinematic technique (i.e., centimetre to decimeter level). In addition, the proposed system will be developed using tightly coupled mechanization, which is carried out in the raw measurements domain. As such, the GNSS signal can still be used even if the number of satellites drops to below four, which is not the case with GPS-alone system. Moreover, MEMS sensors are relatively environment independent, small, inexpensive, light, and consume very low power. This means that the proposed system, in addition to meeting the required accuracy, reliability and availability, will be inexpensive, small and flexible. As such, it offers significant advantages over existing systems. The technological outcome of the proposed research project includes algorithms and estimation methodologies for an autonomous, low-cost integrated GNSS/MEMS-based inertial system as well as a software and a prototype system to support commercial next generation small USV and UAV mapping operations. The developed software can be used as a standalone product or can be integrated with another system, for example, on-board imaging systems. This in turn could lead to the development of a smart system that can automate the entire USV or UAV mission. Such an innovative system has not been developed elsewhere.