## 3 Intuitive and Natural Teleoperation  
In conventional telemanipulation systems, the user controls the remote robotic system with a joystick, gamepad, keyboard and mouse, or 3D mouse and simultaneously receives visual feedback from 2D displays [25; 26]. Robot control is not intuitive and natural to the user [27; 28]. The mismatch between the range of user control space and the limits of input device workspace can increase the difficulty of telemanipulation and lead to poor operation [29; 30]. Another disadvantage of typical telerobotic systems is the lack of depth perception due to monocular, 2D visualization of the remote site [31; 32; 33], limiting operator performance [34; 35] and any feelings of immersion and telepresence in the remote workspace [36; 37]. Intuitive human-robot interaction schemes are needed so the operator can easily guide the robotic system using natural motion. A conventional intuitive teleoperation platform was developed in [38] (Figure 2). The user manipulates the seven degree-of-freedom (DOF) master robot to intuitively drive the slave robot at a distance as if they were directly operating the slave robot. This platform requires a symmetrical relationship between the input (master) and output mechanisms (slave). However, for 2D visualization of the telemanipulation process, the user lacks a sense of presence. Monitoring the interaction process with a 2D monitor on the user side can also distract the user from effective robot control activities. In addition, using the isomorphic master robot as the motion input device on the user side in telemanipulation systems often leads to a significant hardware investment. Several noteworthy studies and frameworks have effectively implemented natural motion retargeting and multimodal feedback. One notable example is the work of [PERSON] et al. [39], in which the authors developed a telerobotic system integrating natural motion retargeting algorithms, significantly enhancing the operator's control precision. Another novel interface that features a motion retargeting method for effective mimicry-based teleoperation of robot manipulators was introduced in [40]. This framework allows novice users to interact with the remote robotic manipulators effectively and intuitively. Additionally, the framework proposed by [41] successfully incorporates multimodal feedback, combining visual, auditory, and haptic cues, leading to improved user immersion and  
Figure 2: A typical intuitive control approach for remote robotic manipulation. (**a**) The user manipulates the master robot of 7 DOF to intuitively drive the slave robot at a distance as if they were directly operating the slave robot. (**b**) The overview of the master–slave teleoperation architecture [38]. task performance. These studies demonstrate the practical implementation of natural motion retargeting and multimodal feedback in XR-enhanced telerobotics, emphasizing their impact on enhancing user experience and task efficiency. With the inevitable limitations in the field of view of remote on-site 2D cameras and the poor quality of the visual feedback sent back from the robot's workspace, users are often unable to achieve a level of situational awareness sufficient for effective and safe remote manipulation tasks [42]. The operator is unable to perceive the physical environment of the worksite in 3D due to the lack of stereoscopic depth information. Typical monocular visual feedback strategies greatly reduce the efficiency of remote-controlled robotic operations [43; 44]. More specifically, the lack of depth information from 2D vision causes ambiguity about the spatial positions of objects in static images. Operators cannot directly perceive depth in monoscopic vision (MV) streams and have difficulty in accurately determining the distance between the robot end-effector and workpieces. Thus, the user perception from 2D visual feedback makes it insufficient to accomplish remote tasks effectively. Hence, the success and efficiency of teleoperated tasks mainly depend on operator skill and proficiency [45; 46].