From Pets to Robots: MojiKit as a Data-Informed Toolkit for Affective HRI Design

Paper Title

From Pets to Robots: MojiKit as a Data-Informed Toolkit for Affective HRI Design

Publication Info

• Topic area: Affective behavior design for animal-inspired social robots
• Keywords: Affective HRI, zoomorphic robots, MojiKit, emotional interaction design, human–pet interaction, behavior prototyping, design reference cards, MomoBot, creativity support, robotic pets

Background and Problem

• Problem / challenge: Designing affective behaviors for animal-inspired robots often relies on intuition, leading to fragmented and inconsistent outcomes. Existing approaches lack systematic, accessible tools for modeling and implementing expressive motions that align with human emotional interpretations.
• Significance: Effective design of zoomorphic robots can enhance emotional resonance and provide companionship, particularly for users unable to own real pets. Addressing design challenges can improve usability and emotional engagement in therapeutic, educational, and everyday contexts.
• Motivation and related work: Prior work has focused on either high-fidelity animal behavior replication or intuition-driven design, but both approaches have limitations in scalability, coherence, and systematic reuse. This paper builds on these efforts by introducing a structured, data-informed toolkit to bridge these gaps.

Solution

• Proposed approach: MojiKit, a toolkit combining structured design reference cards, a zoomorphic robot prototype (MomoBot), and a behavior control studio for prototyping affective robot behaviors.
• Novelty:
  1. Development of a structured, data-informed design reference resource derived from human–pet interaction analysis and ethological literature.
  2. Integration of a tangible zoomorphic robot prototype with a code-free behavior control studio for real-time prototyping.
  3. Empirical evidence demonstrating MojiKit’s ability to empower users to design diverse and emotionally expressive robot behaviors.
• Procedure and key techniques:
  • Analyzed 65 human–pet interaction videos and validated findings with ethological literature and pet-owner interviews to create Design Reference Cards.
  • Built MomoBot, a zoomorphic robot with 16 actuated joints, enabling expressive body movements.
  • Developed a Behavior Control Studio with a timeline-based editor for creating and testing motion sequences on MomoBot.
  • Conducted nine co-creation workshops with 18 participants to evaluate MojiKit’s usability, creativity support, and design outcomes.

Results

• Concrete findings:
  • Participants created 35 validated interaction patterns, with 71.4% conveying positive affect.
  • Creativity Support Index (CSI) scores showed high ratings for collaboration (4.69/5) and enjoyment (>4.3/5), with room to improve expressiveness (3.64/5).
  • Design Reference Cards were rated highly for comprehensibility (4.33/5) and inspiration (~4.2/5).
  • MomoBot’s real-time feedback was effective for understanding parameter-behavior links (4.3/5).
• Advantage over baselines:
  • MojiKit lowered creative barriers, enabling non-experts to design expressive behaviors without programming knowledge.
  • Structured resources facilitated systematic exploration, while the tangible prototype inspired ideas beyond its built-in capabilities.
• Experiments / evaluation:
  • Workshops involved participants with varying levels of pet experience, who collaboratively designed interaction patterns using MojiKit.
  • Mixed-methods evaluation included CSI, targeted questionnaires, and thematic analysis of interviews and design outcomes.
• Limitations and future work:
  • Limited real-world deployment and follow-up evaluations of designed behaviors.
  • Prototype constraints (e.g., lack of perceptual sensing, limited expressive range).
  • Anthropocentric focus, with no consideration of robot–animal interactions.
  • Future work includes enhancing MojiKit’s capabilities, testing in diverse contexts, and exploring interspecies interactions.

Summary

MojiKit is a novel, data-informed toolkit that supports the design of emotionally expressive behaviors for animal-inspired robots. By integrating structured Design Reference Cards, a zoomorphic robot prototype (MomoBot), and a code-free Behavior Control Studio, MojiKit empowers users to create diverse interaction patterns while lowering creative barriers. Results from co-creation workshops demonstrate its effectiveness in fostering creativity, systematic exploration, and emotional engagement. Future work aims to extend MojiKit’s capabilities, deploy it in real-world settings, and explore its impact on human–robot and robot–animal interactions.