Buying a Used Mobile Robot: What to Ask About Its Safety Scanner

A used mobile robot may arrive with a laser scanner attached, but a photograph of that scanner is not proof that the vehicle is ready to operate safely at a new site. A buyer needs to identify the installed equipment, obtain its documentation and understand how the complete vehicle was configured. The new operating environment and intended use also need a proper assessment before deployment.

Identify the actual scanner and its role

Ask the seller for the scanner manufacturer, model, serial number, mounting position and the associated controller or vehicle model. Request the relevant manuals and any available maintenance history. Some sensors support navigation or obstacle detection; others are intended for safety functions. Do not infer the function from a device's shape or from the word laser in a sales listing.

SICK's Safe AGV Easy instructions describe protective fields and how a scanner is evaluated according to travel direction in that system. This is an example of a system design, not the behavior or condition of every used vehicle. The robot manufacturer's system documentation and the installed configuration are necessary to understand the complete safety function.

Ask for the configuration and its history

Request records showing which scanner settings and field sets are installed, who last changed them and whether the vehicle has been repaired or modified. Ask whether the files are readable using currently supported tools and whether access requires a license or account. If the seller does not have the records, treat this as missing evidence to be resolved with a qualified integrator, rather than assuming the scanner uses factory settings.

Ask whether the seller can demonstrate the vehicle's operating modes and provide the corresponding documentation. A mobile platform may use different field sets in different conditions, but the exact behavior depends on its design. Record which mode was active during a demonstration and whether the seller can substantiate the settings. A brief inspection does not replace a review of the vehicle's intended routes and complete safety system.

Record whether the offer includes all scanners, cables, mounting hardware and any associated safety controller. A scanner can be physically present while another necessary component or configuration is absent. Compare the delivered equipment with the agreed inventory and document any discrepancy before acceptance.

Separate warning fields from protective fields

Some systems use a warning field to initiate a warning or speed response and a protective field as part of a safety function. The SICK Safe AGV Forklift instructions describe different responses when its warning and protective fields are interrupted. This example is specific to that system and its instructions; the buyer must consult the documentation for the equipment actually installed.

A sales demonstration that shows a vehicle slowing near an object does not by itself establish the protective function, correct field geometry or stopping performance. Ask the seller to identify what was demonstrated and what was not. Do not redesign field settings based on a brief demonstration or treat a warning field as a substitute for a protective field.

Inspect the equipment and request maintenance evidence

Ask about damaged housings, loose mounts, replaced covers, cable repairs, fault messages and cleaning procedures. A visible indicator can prompt further inspection, but the absence of a warning does not establish that the complete safety system is functioning correctly.

Keep photographs and service records with the vehicle identifier. A qualified technician should inspect and test the system according to the manufacturer's instructions and the site's procedures. Avoid using an unapproved cleaning product, changing alignment or opening a safety device without following the applicable instructions.

Consider the new operating environment

The previous site may have had different routes, floor conditions, traffic, loads or visibility than the proposed workplace. The purchaser should provide the integrator with the intended speed, load, route, intersections and nearby people or equipment. The complete application needs an appropriate risk assessment and commissioning process; the seller's historical use does not automatically establish suitability for the new site.

Ask who is responsible for configuring the vehicle, validating the safety functions, documenting test results and training operators. Include those responsibilities in the purchase and installation agreement. If the system requires updates or replacement parts, obtain written compatibility information from the manufacturer or a qualified service partner.

Make acceptance evidence specific

An acceptance file can list the delivered scanner and controller identifiers, document versions, configuration records, unresolved defects and the checks agreed by both parties. Separate a seller's demonstration from the independent commissioning required at the destination. If a safety-related record is unavailable, write that limitation explicitly and agree how it will be resolved before putting the vehicle into service.

For a separate purchasing issue, read our used mobile robot battery and shipping guide and browse the equipment buying archive. Knowing exactly what evidence accompanies a scanner helps a buyer plan the work needed for a safe installation.