Frame sensing and open-edge sensing are not interchangeable
A framed window gives a robot a raised physical boundary. Frameless panels end with an open edge, so the machine must detect a different change before its drive system crosses the glass. Marketing phrases such as smart navigation or edge detection do not by themselves prove the device is approved for frameless use. Look for an explicit statement in the exact model manual or official support material.
Even within one brand, capability can differ by model. Never transfer a frameless claim from a flagship product to a cheaper or older unit. The safe editorial state is documented match, possible fit—confirm, or not documented. It is not reasonable to infer a safety-critical capability from appearance, suction rating or reviews.
Seams, corners and clamps complicate the pane
A clean outer edge is different from the gap between two balcony panels, an overlap in a shower enclosure or a seam filled with silicone. Clamps, hinges, handrails and standoffs can interrupt the route or create air leakage. Treat every uninterrupted panel separately unless the manual explicitly approves crossing the joint.
Measure the clear width and height of each panel after accounting for hardware. Check whether rounded corners, beveled borders, frosting, decals or cutouts enter the planned path. If the robot maker cannot confirm the arrangement from your measurements and photos, use manual cleaning. A safety feature is not a license to test an undocumented architectural condition.
Setup still requires secondary protection
Open-edge sensing is only one layer. Attach the manufacturer-supplied safety tether to a fixed indoor object before placing the robot, route the cord without tension, clear the area below, and remain present. Keep enough distance from the boundary if the starting-position instructions specify it. Never begin a frameless exterior run where safe recovery would require reaching outside or climbing.
Start on an accessible interior frameless surface if the manual permits it. Watch the first complete boundary approach. Stop and retrieve the unit if it hesitates unpredictably, crosses a seal, loses suction, or produces an edge or pressure alert. Do not catch a falling robot or rely on holding the rope by hand.
How to choose without overclaiming
Filter first for exact-model frameless approval, minimum pane dimensions and supported orientation. Then compare cleaning system, controls, pad availability, cord reach and support. A listing should be eligible for a frameless collection only when a manufacturer source supports that use; popularity or a retailer title is not enough.
If the documentation says only framed windows, reject it for this use. If the documentation cannot be located, label it unverified and ask the manufacturer. This conservative distinction protects the user and makes comparisons more valuable than a broad list of products that merely look similar.
Questions readers ask
Can edge detection prevent every fall?
No. It reduces one risk when used within documented limits. Suction, backup power, tethering, supervision and a controlled area below remain necessary.
Can a robot cross between glass balcony panels?
Assume it cannot cross a seam or gap unless the exact manual expressly permits that transition.
Does thick frameless glass make a robot safer?
Glass thickness does not replace open-edge approval, minimum size, intact surface, tethering or safe access.