# A Systematic Review of Virtual Reality Interfaces for Controlling and Interacting with Robots
## 3 Results and Discussion
### Interaction  
Interaction papers focus on both the development of new interaction techniques for controlling robots in VR and identifying the best interaction practices. Ref. [44] develops a VR interface that incorporates object affordances to simplify teleoperation of two robotic arms equipped with dexterous robot hands. They provide grasping and manipulation assistance by allowing the operator to teleoperate the arms towards an object of interest and then provide an affordance menu. The affordance menu allows the user to select from a list of possible grasps and actions that can be performed on the object. Ref. [45] designs a visual programming system to define navigation tasks for mobile robots. Their system works by constructing a VR environment built from the output of the robot's visual simultaneous localization and mapping (vSLAM) and then allowing users to select high-level landmarks along with task-level motion commands. From there, their system can plan a path for the robot in order to accomplish the desired tasks. Ref. [46] looks at how predictive components can improve operator situational awareness and workload in VR interfaces for multi-robot systems.  
Their results show that there is insignificant improvement when using predictive components. However, the authors acknowledge that these results could be due to lack of operator training in understanding the predictive cues. Therefore, there is additional work to be done in this area. Ref. [47] implements a system that allows users to collaborate with a robot to conduct 3D mapping of indoor environments using VR. Their system works by using VR headset pose data to estimate human intentions, which is then used to navigate a mobile robot to build a 3D map of the environment. This map is rendered inside the VR headset to provide an immersive view for the user.  
There has also been some work towards identifying the best way to interact with robots in VR. Ref. [48] compares two different VR interactions, position control and trajectory control, to remotely operate a robotic manipulator. In position control, the user can place a single waypoint for the robot to autonomously navigate to and the user has the option to stop the motion at any time. In trajectory control, the user can move the arm by pressing a button and the robot will follow the relative movements of the controller. They conduct a 12 person user study comparing their two VR interfaces and find that when using positional control, users, in general, were both faster and more accurate in the tasks. Ref. [49] explores developing a VR interface for humanoids by taking inspiration from VR video games to identify the best control schemes and practices for VR. They summarize a total of 14 VR games, specifically looking at what viewpoint they use, how movement in the game is accomplished, how manipulation is done, and how information is brought up to be displayed. Ref. [50] investigates using different controllers, VR controllers to allow for grabbing and 3D mouses for driving, in operating a pair of robotic arms for a pick-and-place task and ultimately find that using the VR controllers allowed for faster operation due to faster gross movement control.