Designing mobile robots for better human–robot interaction

Human-Robot Interaction (HRI) refers to the complex interplay between people and physical machines. HRI research in the context of mobile robots encompasses many streams of studies, from path planning and motion cues to robot design features as well as broader factors influencing user experiences.

In Haaga-Helia’s HosByte project, we explore HRI design best practices in real-world contexts.

Expressive movement design

Mobile robots refer to autonomous or remotely operated robots capable of moving and navigating through their environment without being fixed to one physical location. A key goal for making mobile robots work safely in real-world settings is to make their navigation legible.

Clear motion cues allow nearby people to quickly understand the robot’s intent, which enhances user comprehension, trust, and comfort. For example, instead of abruptly zipping through a crowded lobby, a service robot might slow down and pause when guests cross its path, using a gentle stop or a soft audio chime as a cue that it’s yielding. Predictability and politeness in motion helps guests feel safe and confident around a mobile robot.

For instance, when designers at Futurice were tasked with developing a robot for the Oodi Central Library, a key insight was to give the mobile robot googly eyes that indicate where the robot is going to turn next (Schwab 2019).

Similarly, through their collaboration with Alepa and more recently Wolt, Starship’s outdoor delivery robots and their extended blinking flag have become familiar sights in many locations across Finland. The robots use the blinking flag to stand out from the environment, to improve detection and to convey intent.

In short, expressive movement design – from smooth, human-aware navigation to small gestures – helps mobile robots convey intentions transparently. This leads guests to perceive them as safer, more reliable, and ultimately more enjoyable parts of the service experience.

Leveraging anthropomorphism and social presence

Besides expressive movement, another major design factor in HRI is anthropomorphism – endowing robots with human-like or pet-like features – to create a warm social presence. People naturally respond to social cues, so giving a service robot a ‘personality’ can dramatically improve how humans engage with it. This can be achieved e.g. through facial expressions, voice modulation, and interactive gestures that make the robot feel like a social actor rather than a mere appliance.

Studies have found that service robots with some human-like attributes (the kind that make users say ‘it’s so cute!’) are more likely to satisfy customers, particularly in hedonic consumption contexts (Guo et al. 2024). The goal is not to fool anyone into thinking the robot is human, but rather to trigger empathy and build rapport.

For instance, BellaBot – a mobile robot used e.g. at HuaDu restaurant in Helsinki – has a feline face and can blink its digital eyes and even purr when you pet its head, much like a friendly cat. This playful touch invites guests to interact and creates an emotional connection. Such robots do not just deliver dinner: they turn the service into an engaging experience.

Effective anthropomorphic design also involves how robots speak and respond. A pleasant, well-timed voice greeting (e.g. a cheerful ‘Hello, I have your order!) and subtle gestures like a nod, a wave, a blink or a blush can make the interaction feel more natural. For over a decade, world’s most popular humanoid robot Pepper has leveraged its expressive eyes, arm movements, and a friendly tone-of-voice to actively engage guests, creating the impression of a social presence (Tuomi, Tussyadiah & Hanna 2021).

This social presence can put guests at ease and even increase trust. Guests tend to ascribe intent and emotions to robots that behave socially, which can have real benefits for service outcomes.

Real-world prototypes as part of Haaga-Helia’s project

To explore HRI design best practices in real-world contexts, we are testing different logistics tasks, e.g. dish collection, information provision and item delivery, with Keenon’s T5 mobile robot during spring 2025. The service prototypes are part of Haaga-Helia’s HosByte-project, and are carried out in collaboration with hospitality tech provider Yonoton, whose key design principle across their product portfolio is user-centric design.

To drive acceptance, a key focus of the real-world prototypes is on exploring design features that drive successful HRI. As part of our testing, we will explore different types of intent expression in mobile tasks, e.g. path planning based on customer flows, pre-planned routes vs. on-demand call of the robot, as well as different interaction features for collision detection.

We will also test different forms of anthropomorphism. At the beginning of the project, we launched a naming competition to help craft the desired persona of our robot. Next, our robot – called Robobby – will adopt different personas, as we test specific interaction modes (tablet vs. voice), scripts for user interaction, as well as of course different AI-generated background music, voices and tones of voice.

Mobile robots for user-friendly interaction

The success of mobile robots comes from blending a practical service with user-friendly behaviour. A robot that simply navigates to you – or for you – might be useful, but one that does so while politely announcing its arrival and e.g. displaying a cheerful icon on its screen becomes a memorable part of the guest experience.

Tech-savvy hospitality leaders have found that embracing expressive movement and anthropomorphic design yields higher guest comfort and often a marketing boost (guests share their robot encounters on social media due to the novelty factor).

Of course, there is a balance to strike – the design should avoid the ‘uncanny valley’ of being too human-like, and always prioritize the task at hand. But when done right, a waiter or room-service robot that moves clearly and behaves warmly can enhance service quality and guest satisfaction in a unique way. In an industry built on hospitality, these design elements ensure the robots are not just efficient gadgets, but charming ambassadors of the brand experience.

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