MSc thesis · UNIST · 2026

A design-to-engineering framework for non-humanoid robot actions

The thesis proposes a three-stage framework for designing contextually appropriate physical actions for non-humanoid robots, together with the tools to apply it.

The bound thesis, a black hardcover titled A Framework for Designing Contextually Appropriate Physical Actions in Non-Humanoid Robots, next to an orange 3D-printed part

Overview

Title

A Framework for Designing Contextually Appropriate Physical Actions in Non-Humanoid Robots

Advisor

Prof. KwanMyung Kim

Committee

Prof. James Self and Prof. Jaeyeon Lee

Defended

December 16, 2025. MSc in Engineering Design, February 2026

Tools developed

A Blender add-on, a web CSV plotter, an iOS AR app and a visionOS app

Evaluated with

Older and younger participants, Blender users, and seven design and engineering experts

Designers work in animation; engineers need parameters. Design intent is lost in the handoff, and robots end up moving as their motors allow rather than as people need. The thesis addresses this gap.

“How can we create a structured framework for designing and evaluating contextually appropriate actions in non-humanoid robots that balance user experience with engineering feasibility?”

Main research question (RQ)

Three stages, with test results feeding back into design

Each stage feeds the next, and test results feed back into design.

  1. 1

    Design robot actions

    Build an action catalogue, decompose motion into components, and measure user preferences.

    Stage 1
  2. 2

    Integrate and export

    Validate animations against the robot’s physical constraints, correct infeasible motion and export data engineers can use.

    Stage 2
  3. 3

    Test in augmented reality

    Place the life-size robot in people’s own homes with AR on iPhone, and check it on Apple Vision Pro, before the hardware ships.

    Stage 3
Diagram comparing a conventional action design workflow, which loops from text and 3D animation through engineering and prototype testing, with the proposed approach, which adds AR deployment and early user testing before engineering
Conventional workflows defer user testing until a physical prototype exists. The framework moves it earlier, into AR.

Stage 1 · Design robot actions

Component-based action design grounded in user preferences

This stage applies the method from the Lemmy study. A designer workshop produced a 22-action catalogue, interviews identified four motion components, and paired comparisons measured preferences.

An early round with 36 younger, multinational participants favored curved paths, whereas older adults preferred straight ones, indicating that motion preferences vary by user group. In the validation study, actions built from older adults’ preferred components scored 7.7 out of 10, against 5.3 for non-preferred ones.

Learn more
Six renders of Lemmy in a dim living room, shot at three focal lengths, each with and without depth of field
Designing the stimuli: the same scene at 35, 85 and 150 mm, with and without depth of field.

Stage 2 · Integrate and export

Plausible animations can be physically infeasible

A two-wheeled robot cannot slide sideways, and a gentle-looking move can demand wheel speeds no motor can deliver. I developed True RoboAnimator, a Blender add-on that enforces these constraints during animation.

Chassis only
The body glides along its path while the wheels stay still.
Wheels keyed by hand
Hand-keyed wheel rotation approximates the motion but is not guaranteed to match it.
True RoboAnimator
Wheel angles are derived from the chassis motion itself, frame by frame.
The True RoboAnimator panels in Blender, with sections for validation, correction, wheel caching and export

Validation, correction and export

  • Validate motion. Flags every frame in which the robot would have to slide sideways.

  • Autocorrect. Replaces infeasible paths with a smooth S-curve or a rotate–move–rotate sequence; corrections are reversible.

  • Wheel kinematics. Computes left and right wheel angles and RPM, with limits on speed and acceleration.

  • Engineering export. Per-frame or fixed-rate CSV, keyframe CSV or JSON for AR, and a web plotter for reviewing the data.

Two correction strategies for an infeasible path: a linear rotate-move-rotate solution and a smooth S-curve solution
Two ways the add-on repairs an infeasible path: a linear rotate–move–rotate sequence, or a smooth S-curve that respects the robot’s minimum turning radius.

Blender user ratings of True RoboAnimator

Mean rating out of 10 from external Blender users after a think-aloud session

  • Responsiveness and stability8.6
  • Fits the existing workflow8.4
  • Better than working without it8.2
  • Overall satisfaction7.6
  • Supports iteration7.4
  • Helps explore and express motion7.0
  • Easy to understand6.8

No crashes were reported. Ease of understanding scored lowest, so the next version should expose its intermediate steps rather than act as a one-click black box. The add-on subsequently passed Blender’s official review and was published on Blender Extensions, where it has more than 7,000 downloads.

Stage 3 · Test in augmented reality

Life-size AR testing in participants’ homes

Screens shrink robots and flatten motion. A native iPhone app anchors Lemmy to the floor at true scale, so participants can observe its motion relative to their own furniture.

The Lemmy AR Experience app: a home screen, an actions screen with a 3D render, an AR view of Lemmy on a real floor, a settings screen with accessibility options, and the TestFlight page
Lemmy AR Experience, the final iteration, distributed through TestFlight. Settings include high contrast, text size, haptics and sound.

A native implementation, from CAD to device

The app is written in Swift with SwiftUI, ARKit and RealityKit. It anchors the robot to the floor and supports placing and repositioning it on detected planes, pausing with a pinch, and capturing screenshots without the interface. It includes 20 animations grouped as base, functional and expressive.

Each animation originates from Lemmy’s engineering CAD, passes through Blender and the add-on, and ships as USDZ, so what people see in AR matches what engineers receive.

Pipeline from SolidWorks to an STL file, into Blender for optimization, animation and correction, then to a USDZ file and a Swift app
SolidWorks → STL → Blender → USDZ → Swift.
A visionOS window listing Lemmy’s action variants, floating in a virtual environment
A visionOS version pairs a menu window with an immersive space, checked on Apple Vision Pro and in the simulator.
Lemmy’s model open in Reality Composer Pro on a Mac
Preparing the model in Reality Composer Pro. Both apps passed Apple’s review for TestFlight.

Participant ratings of the AR experience

Mean rating out of 10. Participants aged 17 to 29 used their own iPhones at home.

  • Clarity8.3
  • Stability8.1
  • Ease of use8.0
  • Helped judge scale, orientation and path7.8
Scale

AR made size and paths legible. Participants could judge the robot’s size, the direction it faced and where it was heading, relative to their own space.

Pet-like

Motion alone did not convey emotion. Shown without labels, expressive movements were often misread. Fast motion was read as alertness, and many participants described Lemmy as pet-like.

Multimodal

Expression requires multimodal cues. Future work will pair motion with the robot’s screen and sound cues rather than rely on movement alone.

Learn more

Expert evaluation of the full framework

Seven experts in their twenties, with two to six years of post-bachelor’s experience, reviewed the full framework. Four were from design (UI/UX, industrial and product design, XR) and three from engineering (robotics software, VR/AR, mechatronics).

Expert ratings after the walkthrough

Mean agreement out of 10

  • AR testing gives valid insights8.6
  • Clear and easy to follow8.4
  • Covers the essential steps8.4
  • A novel or improved method8.4
  • Bridges designers and engineers8.0
  • Viable in real projects7.9
  • Add-on turns animation into engineering data7.9
  • Adapts to other robots and contexts7.6

Expert concerns define the next steps

Experts valued the adjustable motion components (“knobs”), the support the framework gives 3D artists, and the CSV exports. They also raised concerns:

  • The screen, sound and distance channels are not yet covered.
  • AR cannot convey motor noise or weight.
  • Generalization to more complex robots is unclear.
  • The validator’s one-click behavior is difficult to trust.

These limits define the next steps: replicate the preference studies across ages, cultures and robots; support more drive types; add multimodal cues; and test the same exports on real hardware.

Danyal presenting a slide about the AR page of the Lemmy app to three seated reviewers
Presenting the AR app at UNIST.