Reconstructed Reality: Enabling Teleportation-Based Locomotion in Immersive Telepresence

Imagine trying to walk through a room while wearing a heavy helmet that shows you a live video feed of a different room, but the video is delayed by nearly two seconds. Every time you turn your head or take a step, the image you see lags behind your actual movement. This mismatch between what your eyes see and what your inner ear feels for balance is a primary cause of motion sickness in virtual reality. For years, this sensory conflict has been a major barrier to using robots for remote tasks, such as checking on an elderly relative or inspecting a distant facility. When operators use standard joysticks to move these robots, the delay makes navigation feel sluggish and disorienting, often causing nausea that forces them to stop. Researchers have long sought a way to let people feel present in a remote location without the physical toll of that lag.

A team of researchers at the University of Oulu has developed a method to solve this problem by changing how people move through these remote spaces. Instead of trying to steer a robot continuously like a car, their system allows the user to instantly "teleport" to a new location within a digital map of the remote room. While the user is moving in this digital space, the actual robot travels to that spot on its own. Because the user is not watching the robot struggle through the delay, they do not feel the motion sickness that usually comes with the lag. The researchers tested this idea in two stages, first with a pre-made digital map and then with a system that builds the map in real time as the robot moves. Their findings show that this teleportation method significantly reduces sickness and helps people complete tasks faster, even when the video connection is slow.

The core of the problem lies in how the human brain processes movement. When a person wears a headset and sees a video of a robot moving, their eyes tell their brain that they are traveling. However, their inner ear, which controls balance, senses that they are sitting still. This contradiction creates a conflict that the brain interprets as a sign of poisoning, triggering symptoms of nausea and dizziness. This issue is particularly severe when using 360-degree cameras to stream video from a remote robot, because the high-quality video requires more data to send, which increases the delay. In the experiments described, the delay between the robot's action and the user seeing it on their screen was measured at approximately 1.8 seconds. At this speed, trying to steer a robot with a joystick is frustrating and physically taxing, often leading to poor performance as the operator struggles to guess where the robot will be when the video finally catches up.

To address this, the researchers introduced a system called VEIPE, which stands for Virtual Environment Interface to a Physical Environment. In this setup, the user does not steer the robot directly. Instead, they look at a 3D reconstruction of the remote room inside their headset. This digital room is built to match the real one. When the user wants to move, they point at a spot on the floor in the digital room and click. The user instantly appears at that spot in the virtual world, and the robot begins to drive there on its own. During the time it takes for the robot to travel the distance, the user sees the robot moving in the digital space, but because the user's own body is not moving, the sensory conflict is minimized. Once the robot arrives, the view switches back to the live video feed so the user can see the real world clearly.

The researchers first tested this concept using a digital map that had been created before the experiment began. They asked participants to navigate a robot through a room to find specific objects, such as checking if a pill bottle was present or if a trash can was full. Half the participants used the traditional joystick method, while the other half used the teleportation system. The results were clear: those using the teleportation method reported significantly less nausea. On a standard scale used to measure motion sickness, the joystick group scored much higher, indicating severe discomfort, while the teleportation group scored near zero. Furthermore, the teleportation group completed more navigation tasks in the same amount of time. They also reported feeling less mentally exhausted. The participants overwhelmingly preferred the teleportation method, with most stating they would choose it if they had to control a robot again.

To ensure these results were not just a fluke of a pre-made map, the team conducted a second, more challenging study. This time, they used a robot equipped with a special camera that could scan the room and build the 3D map while it moved. This meant the digital environment was being created in real time, rather than being a perfect copy made in advance. The task was more complex, requiring the robot to travel longer distances in a larger space to perform observational checks, simulating a real-world scenario like an elder-care assistant. The delay in the video stream was slightly higher in this setup, measured at 1.8 seconds, due to the higher quality of the video and the processing required for the real-time map.

Even with the added complexity of a live, building map, the teleportation method proved superior. Participants using the real-time system experienced significantly less motion sickness than those using the joystick, though the overall sickness scores were slightly higher than in the first study, likely due to the longer duration of the task. The teleportation group also completed more tasks successfully. The researchers found that the time it took for the robot to travel did not hinder the user's ability to plan their route, because the user could see the entire path in the digital map and jump to the destination immediately. This eliminated the frustration of trying to steer through a laggy video feed. The subjective workload, or how hard the users felt they were working, was also significantly lower for the teleportation group.

However, the study revealed one surprising nuance regarding user preference. While the teleportation method was objectively better for health and performance, the participants did not unanimously choose it as their favorite. In the second study, only about two-thirds of the participants preferred the teleportation method, while the rest still chose the traditional joystick. The researchers noted that some users felt a stronger sense of control when they could steer the robot themselves, even if it made them feel sick. One participant mentioned feeling "disembodied" when using the teleportation system, preferring the direct connection of the joystick. This suggests that while the technology solves the physical problem of motion sickness, the psychological desire for direct control remains a factor that designers must consider.

The researchers also looked at how easy the system was to use. The teleportation method received a slightly higher score on a usability scale, but the scores were not overwhelmingly high. Some participants found it frustrating when the robot could not reach a spot they had selected in the digital map, such as when they teleported too close to a wall or an object. This indicates that the system needs to be smarter about which spots are reachable, perhaps by showing a clear path or restricting teleportation to safe areas. Despite these minor usability issues, the data confirms that the method works. The researchers concluded that using a 3D reconstructed environment to teleport a robot is a viable and effective way to overcome the limitations of high-latency connections.

This work demonstrates that the future of remote robotics does not necessarily depend on faster internet or better cameras to reduce delay. Instead, it may depend on changing how humans interact with the machine. By allowing the user to skip the laggy journey and appear instantly at the destination, the system removes the sensory conflict that causes sickness. The study provides strong evidence that this approach allows people to navigate remote environments more effectively and comfortably, even when the connection is slow. While the technology is not yet perfect, and some users still prefer the feeling of direct control, the results offer a clear path forward for making telepresence systems usable for the general public. The ability to check on a loved one or inspect a remote site without feeling ill could transform how we interact with the world beyond our immediate reach.