## 1 Introduction
They utilized the precision of surgical navigation systems (NAV) to address the hand-eye calibration problem, thereby localizing the mixed reality (MR) camera within a navigated surgical scene. The accuracy of this method complies with the accuracy and stability requirements essential for surgical applications. [PERSON] et al. [19] proposed a real-time two-branch approach that integrated human action-based human factor evaluations and object-based assembly progress observations. The experiments were carried out on human-object-integrated performances in the smart AR assembly, and the results illustrate that the proposed method alleviated the cognitive load. For the teleoperation of robots, recent studies have used MR for gesture recognition to control the digital twin of the real robot arm. The digital twin is a virtual model which is designed to accurately reflect the real object. [PERSON] et al. [20] designed an arm-free human-robot interaction interface (HRI) based on MR feedback. The HRI allows people to control a robot using speech recognition. This method can complete the grasping task, but the efficiency of this method is not high. [PERSON] et al. [21] proposed an MR-based interaction interface that allowed users to create and edit the robot's motion through waypoints. These waypoints represent the position where the robot arm's end effector must move, and a series of waypoints perform a motion. The interaction interface displays the predicted path of the robot arm from one waypoint to the next. Similarly, [PERSON] et al. [22] used an MR device to control the digital twin of the robot arm's end effector to indicate the robot arm's trajectory through gestures. This method also allowed users to simultaneously modify the virtual end effector's six Degrees of Freedom by holding and moving the virtual end effector. For mobile robots, [PERSON] et al. [23]used gestures to move the virtual end effector to control the robot arm on the quadruped robot through the MR device. In addition, remote interfaces can influence the efficiency of teleoperation, and the method of observing workspace can also influence the efficiency of teleoperation. In traditional robot arm teleoperation systems, users can only obtain the necessary information from the 2D display to control the robot arm, but it is difficult for users to obtain information using a 2D display. The main reason for this is that the information on the working scene provided by the 2D display is neither intuitive nor natural for the user. [PERSON] et al. [24] used a single 2D display to show the working scene of the remote robot arm. When users observed the workspace from one direction, they could not perceive the depth directly and had difficulty in accurately judging the distance between the robot arm's end effector and the objects. Because of the difficulty of observing objects, the method of using a single 2D display causes many collisions that occur between the robot arm and the objects. Additionally, users cannot observe the workspace and the controller simultaneously during the operation, which prevents users from paying attention to the robot arm's operation activities. [PERSON] et al. [25] used three monocular cameras to address the difficulty in judging the distance between the end effector and the objects. This method allowed users to observe the workspace and to judge the distances of objects from different perspectives. However, because the teleoperation robot system becomes more complex, the method using multiple 2D feedback to avoid collisions between the robot and the surrounding objects leads to inefficient robot operations and increases the operator's workload. MR makes it convenient for users to understand the work environment and provides users with better experiences. Improving 2D visualization to 3D visualization can offer additional depth information to users [26; 27; 28]. [PERSON] et al. [29] proposed a mixed reality head-mounted display (HMD) that overlaid the anticipated movement of a robot arm to the real environment.