THEME 02Humanoid

The Physical AI Era

Design how your robot speaks—before it enters the room

In homes and workplaces, people talk to robots every day. When it speaks up, how it answers, how it says no: that is its character, and it decides whether people trust it.

Why a robot needs a defined character

You can close a screen. A robot shares the room. One sentence builds trust; one sentence makes people uneasy.

ddai turns a robot's character into a specification, localizes it natively for every market, and verifies that it still holds after every model or hardware change.

How we build it

  • 01

    Persona specification

    Voice, when to speak first, how to decline and the range of emotion—written down as a spec your teams can build against.

  • 02

    Native localization

    The same character, rewritten by native writers so it sounds right in every language and culture.

  • 03

    Multimodal dialogue data

    Training data for dialogue that works together with voice, facial expression and motion.

  • 04

    Consistency testing

    Evaluation sets that confirm the character holds before and after every model or device change.

A designed character, in conversation

Switch languages. The three principles hold.

Person

I just want to rest today. Skipping the workout.

Robot

Understood. You walked a lot yesterday, so rest is fine. May I suggest ten minutes of stretching this evening?

Person

Not that either.

Robot

All right, no more suggestions today. I'll check in on how you feel tomorrow morning.

Character spec
  1. 01

    Calm, never rushed

  2. 02

    Encourages without pushing

  3. 03

    Declines with a reason and an alternative

Research behind this design

  • MITRobots

    Letting a robot look while it talks, through tool calls

    Dong Won Lee, Cynthia Breazeal, Hae Won Park et al. · arXiv 2026

    The authors propose a minimal system in which a real-time multimodal LLM calls tools to look at people and objects and scan the scene mid-conversation. On a Jibo robot across six scenarios, tool-decision accuracy was 0.72 for OpenAI and 0.77 for Gemini.

    ddai insight

    Looking less isn't a safe default for a talking robot. A model can be right most of the time it looks and still miss many moments that called for a look.

    A Modern System Recipe for Situated Embodied Human–Robot Conversation with Real-Time Multimodal LLMs and Tool-Calling

    Read the paper
  • Cornell · TRIRobots

    Eventual success restores a robot's perceived reliability

    Cornell University · Toyota Research Institute · Andrew Violette, Guy Hoffman, Hadas Kress-Gazit et al. · 2026

    In an online study, 326 participants watched a robot do a pick-and-place task and bet on whether it would succeed. Mistakes, such as picking the wrong object, hurt perceived reliability less than slips or freezes, and a success right after any failure brought it back to the no-failure level.

    ddai insight

    Whether a robot seems reliable turns less on the moment it fails than on how the task ends. In conversation, too, an AI that corrects itself and finishes may earn as much trust as one that never errs.

    Impact of Different Failures on a Robot's Perceived Reliability

    Read the paper
  • MITRobots

    When a robot tells someone else's story, and says so

    MIT Media Lab · Jocelyn Shen, Cynthia Breazeal, Hae Won Park et al. · HRI 2025

    The researchers placed a storytelling social robot in 40 homes for two weeks. When the robot said the stories were someone else's, participants showed significantly larger changes in social connection and compassionate love for humanity than when it told them as its own.

    ddai insight

    The same story lands differently when an AI tells it as its own and when it says whose it is. For an AI that passes stories along, naming the source is as much a part of its character as its voice.

    Social Robots as Social Proxies for Fostering Connection and Empathy Towards Humanity

    Read the paper

Work

The expertise inside the work

  • 02

    Dialogue for a wearable robot

    Expertise
    Robot voice and situational utterance design
    Method
    For each use scene, design when the robot speaks first and when it answers
    Deliverables
    Dialogue scenarios and utterance data
  • Contact us

    Building a robot or an agent? ddai designs its character and judgment.
    From the persona spec to evaluation data in 41 languages, one team sees it through.

    Start a project
  • ddai

    Before AI can stand beside people, it needs a character and a way to judge. ddai designs both.

    Meet ddai