Robots are annoying - or not?

Initial results on feared and occurring critical situations in human-robot interaction in public spaces

In February and March 2023, we conducted a comprehensive survey study in the Sedelhöfe underpass in Ulm as a starting point for the further development of communication strategies for robots in public spaces. As part of this study, interviews were conducted with 67 invited test subjects, in which we investigated, among other things, which critical situations can occur when dealing with robots.

Knowledge of these situations helps us to understand where there is potential for improvement in coexistence with robots in public spaces - for example, in terms of involving and educating the public or making adjustments and improvements to the robots themselves.



Methodology of the study – Our study consisted of several parts:


  • Interviews and interaction:
    • The test subjects tested our three project robots (ADLATUS delivery robot, cleaning robot and sweeping robot) and interacted with them.
    • They were then asked, among other things, what critical situations they thought could arise when handling these robots.

  • Video observation: :
    • Observation of reactions of random passers-by in strict compliance with data protection regulations (see previous posts).
    • By analyzing these videos, we described the behavior of people in these and potentially critical situations.

We would like to present the initial results below. First results of the study

What conflicts and critical situations with robots in public spaces were feared by our participants?

A total of 405 specific fears were expressed about our robots, which can be divided into eight areas:

  1. risk of injury: 73% fear that people could be injured by the robots or associated falls
  2. functional limitations: 72% expressed concerns about the functionality and capabilities of the robots that could lead to limitations, such as the robot not being able to move freely everywhere
  3. disturbing/damaging the robots (“robot bullying”): 49% are concerned that the robots could be damaged, disturbed or misused by passers-by
  4. security gaps: 49% fear security gaps or problems due to defects in the robots’ software and hardware
  5. triggering (negative) emotions: 31% stated that the robots could evoke emotions, with fear, fright and confusion being among the most frequently mentioned negative emotions
  6. potential obstacle: 31% see robots as potential physical obstacles in public spaces
  7. walking volume: 13% cited the robots being too loud or too low as a problem
  8. infrastructural problems: 7% mentioned possible infrastructural challenges, such as a lack of space that could arise from the use of (too) many robots

Frequency of feared conflicts and critical situations

How do passers-by behave when they encounter our project robots in the Sedelhöfe underpass?

As part of the study, we observed and classified the reactions of passers-by on three consecutive days at selected times. We recorded 6 hours of video footage in which 428 people showed a behavioral adjustment due to the cleaning or sweeping robot:

  1. reactive behaviors (99%):
    – Slight or strong evasion
    – Repeated evasion
    – Stopping and (repeatedly) evading
    – Running away
    – (Near) collision
  2. proactive behaviors (1%):
    – Standing in front of the robot
    – Standing in front of the robot
    – Inspecting the robot for a longer period of time

Most passers-by who adapted their behavior easily avoided the robots (70%). In 24% of cases, people had to adjust their walking behavior several times, for example by stopping and avoiding the robot again. These stronger adaptations occurred particularly with the sweeping robot and in confined spaces, such as when the robot drove close to the wall, creating a bottleneck. Another reason for stronger behavioral adaptations was the turning of the robot in close proximity to the pedestrians.

Conclusions and outlook

The combination of interview results and video observations reveals that, in addition to technical improvements, spatial conflicts and collisions with the robots pose particular challenges for human-robot interaction. While some passers-by approach the robots with interest, the majority try to avoid them and continue on their way undisturbed.

These initial results will help us in the ZEN-MRI project to develop a better understanding of the interaction between humans and robots in public spaces and to identify factors for improving coexistence. Possible measures for improvement include:

  • Increase the predictability of the robot’s behavior, e.g. by communicating the planned directions of movement.
  • Drawing attention to the robot, especially when people are on an immediate collision course.

Further studies are already planned for this fall. Take part in our short survey to be informed about and invited to future studies with the robots: https://ww3.unipark.de/uc/zen-mri/

Special thanks to Tobias Hekele, who carried out the evaluation as part of his bachelor’s thesis in Human Factors at the University of Ulm.