## 3 Intuitive and Natural Teleoperation
Multi-camera arrangements can provide the relative position of objects and allow users to view and judge the distance from various perspectives, compensating for the limits of a single monocular 2D camera. However, as telerobotic systems become more complex, avoiding robot collisions with surrounding objects with only multiple 2D feedbacks inevitably leads to low robot control efficiency and increased operator workload. Different levels of depth perception in telemanipulation can improve task performance for various manipulation and grasping tasks [47; 48; 49]. Using binocular cameras can provide additional depth information to assist operators. Stereoscopic vision and point cloud are two methods of providing stereo-depth information and have been applied in various telerobotic systems for remote vision [50; 51; 52]. Binocular visual feedback for robotic teleoperation has been widely studied on unmanned aerial vehicles and mobile robots [53; 54]. Leveraging depth perception in remote robot teleoperation tasks for general object manipulation is not well studied on mobile manipulators. In addition, neither multi-camera nor binocular camera setups allow the user the flexibility to continuously change the viewing angle to observe the remote work without introducing additional mechanisms on the robot side [55]. Incorporating haptic feedback in telerobotics offers numerous advantages in creating immersive and natural teleoperation schemes, notably enhancing the user's tactile experience and augmenting immersion [56]. This technological integration enables users to perceive and manipulate objects remotely with a heightened sense of realism. Such realistic feedback proves invaluable in tasks necessitating a keen sense of touch, such as delicate surgical procedures or the handling of fragile items [57]. Additionally, haptic feedback serves to enhance the operator's spatial awareness, offering vital cues about the robot's environment and the forces it encounters. This heightened perception significantly contributes to the precise control and manipulation of the robotic system. Moreover, haptic interfaces alleviate the cognitive burden on operators by delivering intuitive, natural feedback. This intuitive interaction allows operators to concentrate more on the task at hand, reducing their dependence on interpreting visual information [44]. Nevertheless, the integration of haptic feedback into telerobotics is not without challenges. One of the primary hurdles involves ensuring real-time responsiveness, as any delay in haptic feedback can disrupt the user's control and sense of immersion [58]. Achieving high-fidelity haptic feedback demands advanced hardware components and sophisticated algorithms, thereby augmenting the overall complexity and cost of the system. Additionally, the design of haptic interfaces catering to a diverse array of tasks and user preferences poses a formidable challenge [59]. Different applications may require varying levels of force, precision, and feedback sensations, necessitating a delicate balance to accommodate these diverse requirements effectively. Addressing these challenges is imperative for harnessingthe full potential of haptic feedback in telerobotics, ensuring seamless integration and optimal user experience in various telerobotic applications. In the process of integrating robotic teleoperation systems with diverse hardware platforms, several specific challenges were encountered. Ensuring compatibility between various hardware components, such as sensors, actuators, and communication interfaces, was a primary challenge due to differences in data formats, protocols, and communication speeds, which posed hurdles in achieving seamless integration [60]. Additionally, interfacing multiple sensors, including cameras, depth sensors, and force/torque sensors, required careful consideration and calibration to integrate data from different manufacturers in real time, ensuring accurate and coherent information for operators [61].