# An ARCore-Based Augmented Reality Campus Navigation System
## 1 Introduction  
Nowadays, the campus area is gradually expanding with the increasing number of university students. The number of the buildings in the campus has also increased. Thus, it is difficult for freshmen or visiting staff to find a specific building at the campus. In modern campuses, campus navigation systems are often implemented in order to provide navigation services for these newcomers. These campus navigation systems usually provide a web version and an App version. The web version [1; 2; 3; 4] is based on network queries, which is real-time and proactive. However, system users need to switch to the campus intranet in order to obtain information, which brings inconvenience. The App version [5; 6; 7; 8; 9; 10] is designed for calling navigation services provided by the third-party. Thus, the route planning function of such systems is limited by third-party service platforms, and the 2D map interface induces difficulties for users in terms of good interface and experience. The main defects in the existing navigation systems are summarized as follows: (1) During navigation, the buildings are often introduced only with 2D texts, pictures and other information; thus, the navigation experience is not intuitive. Additionally, (2) the system cannot simultaneously provide high-precision navigation for both indoor andoutdoor environments. (3) Several virtual objects from different systems superimpose into the real environment, but the system is designed with little human-computer interaction, resulting in a bad user experience. (4) These systems need to be employed in a networking environment, and some of them are also required to connect with the campus intranet and are limited to authenticated and authorized users, causing inconvenience to newcomers. In order to achieve enhancement to the reality, augmented reality (AR) [11; 12; 13] aims to superimpose computer-generated virtual objects and information resources into a real environment. Its coverage is wide, including a series of interdisciplinary knowledge such as spatial localization technology and computer image technology. The advantages of AR technology [14; 15; 16; 17] are as follows. Firstly, it is possible to integrate different types of augmented virtual information. For example, sensor information fusion technology is used for real-time tracking and for completing the scene extension. Moreover, it can superimpose and supplement augmented virtual information into the real world. Secondly, it can complete the design of the human-computer interaction interface by relying on third-party software on the basis of the visualization. By these processes, it can realize the interaction between real information and virtual information. Finally, it can also improve the accuracy of the system's visual interaction and meet modern requirements for intelligent and refined management. In this paper, we design a mobile campus navigation app that combines visual inertial odometry and ARCore-based virtual and real fusion technology based on the research progress and application status of navigation and localization technology in China and abroad. The characteristics are as follows:  
1. During the whole process, the system superimposes the virtual route into the real environment by the technology of AR. Meanwhile, 3D augmented information is integrated with the real buildings by using the camera in order to enhance the user's sensory experience. 2. The navigation system uses the visual odometry and inertial sensors for the localization and map building in order to solve the problem that the GPS cannot provide users with satisfactory accuracy localization in outdoor situations. Therefore, the system can provide high precision navigation in both indoor and outdoor environments. 3. The system uses Unity as the development platform. By writing corresponding scripts, it can design plentiful human-computer interaction functions according to the different scenarios and user needs. 4.