Normal speed must resume only after confirming that the person has fully left or is safely separated
Aliases: safe restart · safeguarded-space clearance · restart interlock
What it is
Safe restart after workspace clearance requires protective sensing, plus manual confirmation where needed, to establish that no one remains in the hazard zone or that every person has separation appropriate to current motion. Disappearance of the stop trigger is not itself permission to regain normal speed.
Why it happens
A brief absence signal may reflect occlusion, scan gaps, or someone concealed within equipment. Immediate acceleration gives nearby people no time to form an expectation of motion. Safe restart therefore latches state: clear the entry condition, verify the space, issue a perceptible pre-start warning, and reset deliberately. Any new entry revokes permission.
Studying it
Occlusion, staggered departure of several people, sensor chatter, reset location, and start warning can vary while measuring restart with someone present, recovery delay, reset errors, and prediction of initial motion. Power restoration, controller restart, and re-entry after reset belong in the test set.
Where it stops holding
Visual clearance is limited by sight lines and memory, while one presence sensor may miss cavities, platforms, or machine interiors. Safe separation varies with speed, payload, and stopping performance rather than remaining a fixed floor mark. Restart after an emergency may also require fault diagnosis.
Applying it
- Latch protective events and release them only after all zones remain stably clear and an authorized person resets from outside.
- Announce direction and timing before motion, begin in a restricted mode, and revoke restart on renewed entry.
- Rehearse multiple people, concealment, tailgating, sensor chatter, and power restoration; no single reset action may start normal motion with a person inside.
Related
- Same group: X5.05.1 Detecting a person in the workspace requires immediate slowing or stopping · X5.05.2 Response must distinguish accidental intrusion from authorized collaborative entry · X5.05.4 Frequent false stops encourage operators to bypass safeguards
- Adjacent: X5.03 Emergency stop · X2.01 Previewing action intent
- Search terms:
safe restart·manual reset·presence sensing