Field Notes
Engineering observations from the warehouse floor. Proximity sensing, safety compliance, deployment operations, and human-robot interaction research from the Closer team in Fukuoka.
Measuring robot obstacle response time: what 80ms means for a moving aisle
How we measure proximity-triggered deceleration to a stop, and why the 80ms figure matters for operators planning mixed-traffic aisles alongside human pickers.
Deploying without exclusion zones: a logistics operator's first week
Notes from a Fukuoka 3PL pilot -- what changed operationally when the cage came down and the robot shared the aisle from day one.
Depth camera and ultrasonic proximity: why we use both
Neither sensor alone handles every aisle scenario. Here is how the two layers complement each other in our sensing architecture.
ISO 3691-4 and what it actually requires from an industrial mobile robot
A plain-language breakdown of the safety standard that applies to autonomous mobile robots in industrial settings -- and how each requirement maps to robot behavior.
Floor tape, magnetic strips, and software zones: tradeoffs for dynamic aisle layouts
Operators ask whether they need to repaint or retape floors when they reconfigure aisles. Short answer: no. Longer answer below.
Human-robot shared aisle: what ergonomics research says
A review of academic and industry findings on how workers adapt their behavior around mobile robots in shared aisles -- and design implications for robot motion.
Integrating a mobile robot with your WMS over MQTT: a practical guide
Step-by-step notes on connecting Closer's fleet API to a warehouse management system -- topic subscriptions, task dispatch payloads, and status feedback.
Before you deploy a floor robot in retail: a 12-point readiness checklist
Questions to answer before a robot goes live in a retail space -- from aisle width minimums to staff briefing requirements and emergency stop placement.
Why we added floor-contact force sensing as a third proximity layer
Camera and ultrasonic sensors handle above-floor obstacles well. Floor-contact force feedback catches what they miss: a bag on the floor, a child crouching, a misplaced pallet foot.
Calculating ROI on a cage-free mobile robot: what the numbers look like
Cage installation, floor marking, and reconfiguration downtime add up. Here is a rough model for operators comparing fenced versus proximity-aware deployment.
Building hardware in Fukuoka: what the city offers a robotics startup in 2025
Why Fukuoka works as a base for hardware R&D -- proximity to manufacturing partners, logistics density, and the Tenjin startup ecosystem.
Three design principles for a robot that works arm-to-arm with people
The earliest decisions we made when designing Closer -- what it means to build proximity-first rather than cage-first, and the tradeoffs that follow.