Hi everyone my name is Markku Suomalainen from the university of Oulu, Finland and I'm presenting our
work claiming that unwinding rotations improves user comfort with immersive telepresence robots
Before we get to the main point let's discuss immersive telepresence, the use case we propose
Essentially, we have a remote user who's wearing a virtual reality Head-Mounted Display (HMD)
On the left (the figure is also from our user study), then somewhere else is a mobile robot
which is equipped with a 360 degree camera streaming video into the hmd
such that the user can just look around in the remote environment as they normally would they
can also move the robot around, tell it to move somewhere with some unspecified means
So why should we use an HMD over the current commercial telepresence robots such as
the Beam on the left. They are much nicer looking than our prototype on the right The main reason
is immersiveness. An hmd is more immersive so you are kind of really in there because all
you see is the environment and that has been shown to have a strong connection to presence
with the work of Mel Slater. Then why do we care about presence? There's an interesting study in
HRI a few years back showing that in a group work if there were three local people
and one person through a telepresence robot the person through the telepresence robot
spoke less and found the tasks more difficult and we believe that might be due to the lack
of presence, they really didn't feel as if they really were there with the other people.
So why isn't everybody then using an HMD? A few challenges, a couple of technical challenges with
bandwidth and stitching images from multiple videos together they are under active research
they are not really our concern there are already research-level solutions to this
VR sickness however is what we care about so similarly as you might get motion sick
in a car you might get sick in VR because your eyes see something but your vestibular organs
sense something else so you see rotation on the screen but you don't sense it and that can cause
nausea, headache, even vomiting
To remedy that we propose unwinding the rotations
of the telepresence robot such that the user never actually experiences the rotational
motions which are shown to be stronger than translational motions in causing VR sickness.
How do we do that? If you will look at the figure in figures (a) and (d) the robot is approaching a
cross section, figure (a) is the user's point of view, and then the robot makes a turn and if the
rotations are unwound so the robot rotates right, however the user's viewpoint at the same time
rotates left so the user never sees the robot physically rotate but keep staring at the wall
and then the robot starts moving from the user's point of view to the right.
If this is not done, then as in figure (c) the user will see the direction where the
robot is headed right away so obviously this needs that the user then must have a
means to physically rotate themselves such as a swivel chair.
We pre-registered for hypothesis of what would happen if,
for a telepresence robot moving autonomously, and the person aboard through an hmd,
so what would happen if the rotations are unwound.
Those hypotheses were that the users would get less sick, they would prefer the unwinding, and
they would find it more comfortable, and finally they would retain their sense of orientation
such that the error in path integration is not increased. We worry this might happen if people
do not rotate themselves to face the robot's direction of motion, then it might be that they
lose their sense of orientation which is something we don't want to cause for telepresent people
To test our hypothesis we designed a virtual environment
in blender and unity we had 34 participants
who saw two conditions of the same video either unwound rotations or coupled rotations,
which is what we call when the user's viewpoint rotates along with the robot.
We also collected head motion data during the experiment, asked participants
questioners and at the end asked them to point towards the origin,
and we had also some simulated humans there as you see on the figure on the bottom left
And then I can happily say that all our hypotheses were confirmed.
To measure VR sickness we use the simulator sickness questionnaire,
the SSQ, a very standard method for measuring VR sickness. There was a significant difference.
Then for preference and comfort we used forced-choice questions after the participants had
seen both videos, and there was also a significant difference we also asked about intuitiveness we
didn't pre-register that but users found it intuitive also to rotate themselves,
and there was no significant difference in the path integration error.
Other results: through the head tracking data we found out that the participants
did rotate themselves to face forward as in the robot's direction of motion,
even though we never told them they have to do it, they still instinctively did it. And
as you can see from the figure, people had also a different amount of rotation so the
two figures above are from the same participant the two below are from another participant so
some looked around less but it made no difference whether there was unwinding or not. And also the
speed of one meter per second was considered adequate, distance to the walls was okay,
however one meter distance to people from the camera viewpoint was considered a bit too close.
To conclude: for autonomous motions of a telepresence robot it's beneficial to
unwind the rotations rather than make the user's viewpoints rotate with the robot.
There's a bunch of interesting follow-up questions, such as: now we assume that the
user can, for example, use a minimap to choose the destination. However, if somebody wants to use a
joystick is it still okay to unwind the rotations, or does that make it too confusing for users?
Does unwinding increase the feeling of presence even? We had some of the qualitative data pointing
that way we might want to study that in the future. And then of course further research
in two-way communication through HMD and the 360 camera, because now we only considered the remote
user watching things. And then we also presented a future work of showing this with a real robot,
so we are happy to say that we currently have run the experiments and we are now analyzing the data
and hopefully by the time the conference happens I can give you an archive link to a submitted paper
showing what happens when all this is done, instead of simulation, it's done on a real robot
That's it, thanks a lot, please don't hesitate to send me a mail if you have any further questions,
I will be happy to talk to you about this and thanks for listening.