In this paper, we address the problem of relative localization of two mobile agents. Specifically, we consider the Dual-IMU system, where each agent is equipped with one IMU, and employs relative pose observations between them. Previous works, however, typically assumed known ego motion and ignored biases of the IMUs. Instead, we study the most general case of unknown biases for both IMUs. Besides the derivation of dynamic model equations of the proposed system, we focus on the observability analysis, for the observability under general motion and the unobservable directions arising from various special motions. Through numerical simulations, we validate our key observability findings and examine their impact on the estimation accuracy and consistency. Finally, the system is implemented to achieve effective relative localization of an HMD with respect to a vehicle moving in the real world.

翻译：本文研究了两个移动代理的相对定位问题。具体而言，我们考虑双IMU系统，其中每个代理配备一个IMU，并利用两者之间的相对位姿观测。然而，以往的研究通常假设已知自身运动并忽略IMU的偏置。相反，我们研究了两个IMU均存在未知偏置的最一般情况。除了推导所提出系统的动态模型方程外，我们重点进行了可观测性分析，包括一般运动下的可观测性以及各种特殊运动导致的不可观测方向。通过数值仿真，我们验证了关键的可观测性发现，并分析了其对估计精度和一致性的影响。最终，该系统被实现用于在真实世界中实现头戴显示器（HMD）相对于运动车辆的有效相对定位。