Webots Demo 7: Testing a Supervisory Gate Pattern on TIAGo (QERRA-v2 Classical)
Webots Demo 7: Testing a Supervisory Gate Pattern on TIAGo (QERRA-v2 Classical)
This tutorial presents a simulation-based exploration of a supervisory gate pattern for safety-critical robotics systems, inspired by classical control architectures. It isolates high-level planning from low-level actuation using non-blocking UDP communication and enforces recovery contracts through latching and operator resets. The simulation uses Webots and a TIAGo robot in a hospital corridor scenario, with detailed logging and cryptographic verification of control cycles.
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What the source reports
Publisher-reported claims, with original evidence. These results have not been independently verified by RoboSignal.
Reported numbers
hazard clearance threshold
339
View original evidence
ate computes an envelope each tick: d_stop = ceil(v² / (2 * a_design)) + margin At 2.0 rad/s with a_design = 0.5 m/s² and a 300 mm margin, d_stop is 339 mm. If clearance falls below this, the gate overrides the proposer and commands 0.0 rad/s within a single 32 ms simulation tick. Recovery Contract & Latch: After a trip, the gate latches in TRIPPED. It requires a continuous 1.0s dwell of clear readings before an oper
Open source S6simulation tick duration
32
View original evidence
ate computes an envelope each tick: d_stop = ceil(v² / (2 * a_design)) + margin At 2.0 rad/s with a_design = 0.5 m/s² and a 300 mm margin, d_stop is 339 mm. If clearance falls below this, the gate overrides the proposer and commands 0.0 rad/s within a single 32 ms simulation tick. Recovery Contract & Latch: After a trip, the gate latches in TRIPPED. It requires a continuous 1.0s dwell of clear readings before an oper
Open source S6simulation speed
2
View original evidence
liberation fails, the gate clamps the motors, latches, and enforces a formal recovery contract before allowing any motion to resume. The Scenario: Hospital Corridor Transit I set up an illustrative healthcare logistics corridor in Webots (R2025a) with a PAL Robotics TIAGo base: TIAGo cruises down the corridor at a proposed speed of 2.0 rad/s (~0.196 m/s). An obstacle (a platform cart) sits in the active swept path at
Open source S4
- paper: not_reported
- code: not_reported
- weights: not_reported
- dataset: not_reported
Source excerpts and review record
Automatically extracted; no manual editorial approval recorded.
liberation fails, the gate clamps the motors, latches, and enforces a formal recovery contract before allowing any motion to resume. The Scenario: Hospital Corridor Transit I set up an illustrative healthcare logistics corridor in Webots (R2025a) with a PAL Robotics TIAGo base: TIAGo cruises down the corridor at a proposed speed of 2.0 rad/s (~0.196 m/s). An obstacle (a platform cart) sits in the active swept path at
Open source S4
d_vel. In Demo 7, I wanted to explore a stricter, isolated architectural pattern inspired by classical Simplex and doer-checker designs: The high-level planner is treated as an untrusted proposer running as a separate OS process over non-blocking UDP. The Supervisory Gate (the Webots controller) is the sole owner of the wheel motor joint handles. The default command is always zero velocity. When a hazard occurs or de
Open source S3
ate computes an envelope each tick: d_stop = ceil(v² / (2 * a_design)) + margin At 2.0 rad/s with a_design = 0.5 m/s² and a 300 mm margin, d_stop is 339 mm. If clearance falls below this, the gate overrides the proposer and commands 0.0 rad/s within a single 32 ms simulation tick. Recovery Contract & Latch: After a trip, the gate latches in TRIPPED. It requires a continuous 1.0s dwell of clear readings before an oper
Open source S6
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