## 4 Conclusions and Future Work  
This work presents the design of an MRS-based intuitive telemanipulation paradigm and a user-study evaluation of three control and visual feedback HRI modes on a practical robotic arm-hand platform. The particular interest lies in the potential benefits of deploying an MRS-enhanced 3D vision/motion mapping approach to improve the work efficiency and situation awareness of unskilled operators in teleoperated pick-and-place and assembly tasks. The IRT system introduced in the paper enabled novice users to intuitively and naturally perform high-quality manipulation tasks at a distance. The proposed MRS HRI interface for robotic tele-control is designed and implemented by leveraging the 3D mapping of motion and vision through an MR subspace. An intuitive and natural interaction scheme was achieved by mapping the user's hand motions to the robot movements and applying spatial velocity-centric control techniques. A VCMM approach was implemented to accurately track the operator's hand movements and minimize aggressive velocity commands, while generating smooth movement in the two typical manipulation tasks. A 3D point cloud rendering architecture was deployed in the MRS paradigm to form an incorporated 3D visualization of the remote site, provide the desired depth perception of the workspace, and maintain the inspection of the workpieces, remote site, and digital twin situated in the MR subspace as a whole. Telemanipulation experiments of novice operators were carried out to test the proposed intuitive teleoperation of the robotic platform. Figure 7: Boxplots of subjective measures about ease-of-use and usefulness for each HRI scheme across tasks. **(a)** The ease-of-use factor of user acceptance and perception; **(b)** the usefulness factor of user acceptance and perception. MRD and MRS denote MR SpaceMouse and MR subspace, respectively. Telemanipulation experiments show that the MRS-integrated scheme reduced aggregate task completion time by 48% compared to the 2D Baseline module, and 29% compared to the MR SpaceMouse module. The MRS-enhanced 3D mapping of motion and vision paradigm improved completion time for operators with minimal technical knowledge. Further, the learning time of the training tasks with the MRS scheme decreased by 53% and 36% compared to the 2D Baseline and MR SpaceMouse approaches, respectively, indicating that extra learning was required in the two typical HRI modules to reach the same competency as in the proposed MRS imitation-based HRI module. Finally, the proposed MRS teleoperation scheme achieved the desired telemanipulation results for novice users.And this scheme significantly reduced the physical and mental demand and frustration of participants, while offering higher user acceptance. Overall, the MRS teleoperation scheme for robotic arm-hand teleoperation presented improved remote pick-and-place and assembly performance of operators with minimal technical knowledge. The proposed teleoperation scheme using integrated 3D mapping of vision and motion through an MR subspace involving intuitive movement control provides improved tele-control performance of manipulation tasks and reduces the workload of operators. The following recommendations are presented for the extension of the current work. These include two major aspects of improvement. The first part regards using the haptic effect to further improve the developed immersive teleoperation platform. In the proposed telemanipulation schemes, the haptic effect on user performance, system usability, and collision avoidance was not investigated. Both haptic and tactile feedbacks have the potential to further improve task performance and users' situational awareness. The second part is about using machine learning strategies to learn the operator's behavior and predict their intentions for the latency mitigation for long-distance scenarios, and employing cloud computing to achieve better management of the developed telerobotic infrastructure. Teleoperation enables the most productive utilization of scarce expertise.