## 1 Introduction
Compared to traditional video-mediated collaboration, MR-based remote collaboration offers more natural and intuitive interactions, reduces task execution time, offers a more engaging user experience, and enables users to share important nonverbal cues, which have been found to increase empathy, reliability, efficiency, and collaboration [34]. MR-based collaboration for interactive tasks has recently been used in academia and industry. It has shown great potential in multiple areas, such as telemedicine, education, training, remote assistance, maintenance, intuitive HRI, and other remote collaboration tasks [35]. MR systems continue to make new advances, creating imaginative and interactive schemes that push the edges previously explored in Computer-Supported Cooperative Work (CSCW) [36]. Three complementary factors that can enhance collaboration in MR environments are annotation techniques, collaborative object manipulation, and perception and cognition [37]. MR has been applied to robotic teleoperation systems to enhance user perception of the remote side in order to enable immersive robotic teleoperation (IRT) [38; 39; 40]. A three-dimensional virtual world similar to the slave side can be simulated through MR and displayed to the user on the master side. By implementing MR as an HRI interface, the user experiences a physical presence in the remote environment, and co-existence with the robotic platform via the MR subspace, while guiding and monitoring the robotic platform in the local user space [41; 42]. MR-enhanced teleoperation allows direct mapping of control commands and the actions between the user and the robot, and has the potential for performance enhancements by serving as an intermediary for the integration of imitation-based motion mapping and 3D visualization [43]. Most recent research on MR-enhanced teleoperation systems has focused on collecting demonstrations for robotic learning, solving long time delays, the development of immersive manipulation, and poor virtual transparency problems [44; 45; 46]. However, those tele robotic systems do not fully exploit the potential performance enhancements provided by using the MR subspace as an intermediary for the integration of imitation-based motion mapping and 3D visualization mapping. In this paper, an MR-enhanced velocity-centric mapping scheme for tele-control is proposed to ensure natural and intuitive robot interaction with effective 3D visual feedback. Precise hand motion tracking and robot movement control are achieved. Acceptable remote manipulation results are accomplished for novice operators by reducing the reliance on operator skills. Spatial motion mapping involves linear velocities and angular velocities. The updated six-vector spatial twist, a representation of the linear and angular velocity of users' hand motions, is transmitted from the user space to the robot space. The integration of spatial motion mapping and 3D visual feedback through the MR subspace is applied in robotic teleoperation as an interface to enable novice users to remotely control the robotic arm-hand system for performing manipulation tasks in harsh, unstructured situations. To analyze system performance, the isometric-rate tele-control paradigm through MR-based 3D motion and visualization retargeting scheme for teleobotics is compared to the isotonic-position 3D interaction condition and conventional 2D baseline over two tabletop object manipulation experiments. This paper is organized into four sections. The first section presented here describes the background, research objectives, and contributions of this research. Section 2 (Materials and Methods) highlights the system overview, experiments and analyses. Section 3 (Results and Discussion) presents the objective and subjective measures of the experiments. Section 4 (Conclusions and Future Work) summarizes the research outcomes and next steps in future work.