Security Robot Winter: Operation in Frost and Snow

The plant manager of a logistics site in Upper Austria called us on 14 January 2024 at 04:17. Outside temperature minus 17 degrees. The guard at the west gate had been unreachable since 03:40. By around 05:30 the picture cleared: the colleague was sitting in the heated gatehouse container and had aborted the outside round because of black ice. This is not an isolated case, this is January operations in the DACH region. The use case for security robots in winter sits exactly here, and this is where marketing material parts ways from a defensible specification.

Security Robot Winter: What DACH Operations Actually Demand

Anyone specifying patrol robots for frost starts with the temperature window. Minimum requirement for German, Austrian and Swiss industrial sites: minus 20 degrees to plus 50 degrees continuous operation. Specifying below that means buying a device for three quarters of the year.

The IP rating decides the rest. IP54 covers light rain and splash water. For snow drifts, melting snow on sensor domes and icy meltwater during a thaw, you need IP65 or higher. The difference matters when the robot drives through a puddle at 06:00 with dissolved road salt in it.

Surface conditions shift through the day between slush, bare ice and wet road salt. That affects traction, sensor height and braking distance directly. A sensor ring at 35 cm height disappears inside the snow pile at the kerb. Round-the-clock shifts also mean patrolling at minus 15 degrees at 03:00, with nobody around to push the device back into the hall.

Important portfolio distinction: the QR-2 outdoor robot with thermal sensors is specified and contractually released for these conditions. The QR-1 is not. QR-1 runs indoors and in mild outdoor climates, but has no release for continuous winter operation. Anyone deploying QR-1 outdoors in January at minus 12 degrees loses warranty and insurance cover.

Battery Behaviour and Lithium Chemistry in Frost

Lithium-ion cells are the most critical component in winter. At minus 10 degrees, standard cells lose around 20 percent of usable capacity. At minus 20 degrees up to 35 percent. This is not a software question, this is electrochemistry.

Worse than the capacity loss is the charging process. If a lithium cell is charged below zero degrees internal cell temperature, metallic lithium plates onto the anode. This lithium plating is irreversible, permanently reduces capacity and raises fire risk. Any security robot without active battery preheating is a warranty case in preparation during winter.

The QR-2 uses an insulated battery box with a heating foil. The charge management releases charging current only once the cell reaches plus 5 degrees internal temperature. That extends the docking process in January by a few minutes, but protects cell chemistry. Patrol intervals still shorten by around 15 percent in winter. Anyone running a 90-minute outdoor round in summer plans for 75 minutes between docking phases in January.

The docking station itself must be thermally designed. A station standing outdoors at minus 18 degrees without its own heating is an ice sculpture with a plug contact. With spare-battery exchange inside the docking phase, downtime per swap falls below 4 minutes, provided the personnel are trained.

Thermal Sensors and Person Detection in Snowfall

Heavy snowfall reduces usable RGB visibility to 8 to 15 metres. In a strong snowstorm, a person in dark clothing at 12 metres distance can become invisible to a standard camera. A thermal camera in winter sees the same person reliably up to 60 metres, because the skin surface is around 30 degrees warmer than the environment.

Person detection via heat signature works even when someone wears camouflage clothing or snow-covered jackets. The chest and face region radiates regardless of textile pattern. That is the operational reason why thermal sensors in winter perimeter security are not optional.

LiDAR delivers excellent geometry data, but has a noise problem in heavy snowfall. Every snowflake is a reflection point. Without calibrated filter algorithms, the result is a point cloud of ghosts. The QR-3 for KRITIS with LiDAR combines LiDAR with thermal and compensates for single-modality failures contextually. When LiDAR reports noise, the thermal track gains weight. When the thermal camera briefly ices over, LiDAR takes over the geometry.

The false-positive rate rises with snow drifts when contextual motion filters are missing. A wind-driven snow cloud can trigger poorly parametrised detection. The fix is not sensor shutdown, but motion-pattern filters that distinguish snow drift from human step frequency.

Surface Conditions, Traction and Drivable Routes

No mobile outdoor robot in snow drives through 15 cm of fresh snow. The honest upper limit for current platforms is 8 cm. That means operationally: the clearing service must prioritise patrol routes before shift start, not only after clearing the access lane for the trucks.

On iced surfaces, permissible travel speed drops from 1.5 m/s to 0.8 m/s. Cornering radii grow, because the tyres build no lateral grip. Anyone ignoring this in the patrol configuration will see robots sliding into outer walls in January.

Road salt attacks bearing seals. This is not a theoretical problem, it is measurable at the drive axles after eight weeks of salt exposure. Maintenance intervals in the winter half-year therefore shorten from semi-annual to quarterly. Quarero builds this into the service plan.

In practical implementation, we define winter routes separately from summer routes together with the client. Gradients above 8 percent are blocked when ice forms, and we cover the sector with a fixed camera plus thermal module. That is a design decision, not a workaround. Anyone planning this in November has no 04:17 phone call in January. A deeper structural breakdown is in the post Perimeter Security in the Industrial Park.

Maintenance, Cleaning and Seal Care in the Winter Half-Year

Winter maintenance is visual inspection plus mechanical care. Weekly, the in-house guard or the Quarero technician checks sensor domes for ice build-up and seals for salt crystals. Salt crystals in a sealing lip act like sandpaper. Ignore them for six weeks, and the seal gets replaced in spring.

Pressure washers are permitted, but not all of them. Maximum 80 bar, minimum 30 cm distance to the sensor dome, never directly onto sealing gaps. Cleaning with 150 bar from 10 cm pushes water past the sealing lips into the housing. The robot then runs for another two weeks and dies in February.

Tyre tread is measurable. Monthly tread measurement, lower limit 3 mm in winter. Below that, traction on slush is no longer acceptable, and braking distance extends by several metres.

In the Robotics-as-a-Service model, maintenance is included in the monthly service price. No additional maintenance contract, no hourly rate per deployment. In case of complete failure, Quarero contractually provides a replacement device within 48 hours. This is where RaaS differs from purchase: the operator does not carry the hardware-availability risk.

Comparison Personnel Guard vs. Robot in Winter

The comparison gets clearer in January than in May. Guard personnel at minus 15 degrees need shortened outdoor intervals, have contractually regulated break duties under cold exposure, and show significantly higher sick rates in January and February than during the rest of the year. This is not a criticism of personnel, this is occupational medicine.

The BDSW industry data document a cost trend in the security industry that runs above general minimum-wage development, and a structural staffing shortage that becomes sharpest in winter operations. A 24/7-staffed outdoor post currently costs between 15,000 and 25,000 euros per month in the DACH region, depending on tariff area, hardship allowances and shift premium structure.

A QR-2 with winter specification in the RaaS model sits at around 3,500 euros per month, including maintenance, software updates and replacement-device guarantee. The robot does not take breaks, does not freeze, does not claim a hardship allowance and does not call in sick. It does not replace the escalation competence of a trained employee.

The operationally most stable configuration is therefore the hybrid model: the robot handles the outer perimeter, the human sits at reception or in the control room and handles escalation, visitor reception and intervention coordination. The detailed calculation with tariff areas and premium factors is in the TCO comparison guard service and robotics.

Regulatory Requirements and Conformity

Three frameworks are relevant for winter operation. First, EN ISO 13482 defines safety requirements for mobile service robots. The standard was originally developed for care and assistance robots, but is applied analogously to patrol robots because human-robot interaction is comparable.

Second, the EU Machinery Regulation 2023/1230 obliges the manufacturer to a risk assessment of environment-specific deployment scenarios. This explicitly includes weather conditions. A manufacturer who distributes a robot without documented winter limits does not meet the regulation.

Third, the BSI KRITIS Regulation requires KRITIS operators to document availability measures, including under extreme weather conditions. Anyone operating critical infrastructure must demonstrate that perimeter security continues to function at minus 20 degrees and in a snowstorm. A patrol that fails on black ice is a gap in audit documentation.

Quarero supplies a declaration of conformity and written weather-operation limits with every contract. From an insurance standpoint, this written weather specification is a precondition for operating liability coverage. Without it, the operator stands alone in a claim case with the statement that the robot was "somehow winter-capable". That does not hold up in court. Additional placement in the overall concept is at Perimeter security overview.

Winter Pilot Project: 14-Day Test on Your Own Site

The sober path to an investment decision is the test on your own site, not the demo on a dry plant car park in September. Quarero provides a QR-2 for 14 days. Delivery within 48 hours of signing the pilot frame. Briefing the security management takes 2 hours.

Test parameters are fixed in writing before the start: 3 patrol routes, of which at least one outdoor route with road salt exposure, 2 night shifts per week between 22:00 and 06:00, full documentation of all failures, sensor quality, false-positive reports and battery behaviour. We measure what is measurable, and write down what is not.

On day 15, Quarero project management and the client's security management sit together and evaluate. The result is either a concrete rollout plan with routes, docking locations, maintenance intervals and interfaces to the existing control room, or a justified rejection if site conditions do not fit. Both are legitimate.

If the project moves into the 24-month RaaS contract, the pilot device stays on site. No return, no second lead time, no second briefing. The patrol configuration from the pilot is carried over and fine-tuned in live operation.

Anyone who wants to test winter operation on their own site starts with the pilot enquiry to Quarero or requests the data sheet for the QR-2 outdoor robot with thermal sensors directly. In January the test starts too late. In October it is on time.