What building a service robot involves
A service robot, such as a delivery, cleaning, reception or telepresence robot, combines a chassis, a drive system of motors, wheels and gearboxes, a large lithium-ion battery pack, sensors for navigation and safety (LiDAR, depth cameras, ultrasonic sensors, bumpers and cliff sensors), an onboard computer, displays and cosmetic covers. Manufacturing it is a box build: dozens of subassemblies from many suppliers come together in a largely manual final assembly, followed by sensor calibration, drive tests and burn-in on every unit.
Volumes per model are usually far below consumer electronics, often in the hundreds or low thousands of units a year, while the bill of materials is long and multi-tier. That changes the economics compared with consumer electronics. Tooling decisions trade upfront cost against unit cost and cosmetic quality, supplier management covers a long tail of mechanical and electrical parts, and safety in spaces shared with people is a design input rather than a test at the end. Serviceability matters as much as build cost, because these robots are repaired in the field for years.
Architecture and key subsystems
| Subsystem | Typical content | Sourcing considerations |
|---|---|---|
| Chassis and frame | Sheet metal, welded steel or aluminum extrusion | Dimensional accuracy at sensor and wheel mounts, corrosion protection, welding distortion |
| Drive | Hub motors or motors with gearboxes, motor drivers, encoders, casters, suspension | Torque, noise and braking behavior; consistency varies widely between hub motor suppliers |
| Battery | Lithium-ion pack with battery management system, often 24 V or 48 V | Pack maker qualification, cell traceability, UN 38.3, and a safety standard suited to the use, such as IEC 62619 or UL 2271 |
| Sensing | LiDAR, depth cameras, ultrasonic sensors, IMU, bumpers, cliff sensors, emergency stop | Lead times, calibration needs, laser classification of LiDAR units |
| Compute | Embedded processor or GPU module, storage, networking | Product life and availability, thermal design, ownership of the software stack |
| Covers and interface | Large plastic or composite covers, displays, speakers, trays or compartments | Tooling route, paint and color matching, cleaning-chemical resistance |
| Charging dock | Contacts, power supply, alignment features | A separate product with its own certification and test |
Tooling for low volumes
Covers are the largest visible parts and the largest tooling decision. The main routes are:
- Thermoforming: low tooling cost, limited detail and wall control, suitable for simple shapes
- Reaction injection molding: large, painted parts from lower-cost molds, widely used for covers at modest volumes
- Aluminum injection tooling: faster and cheaper than steel, with a shorter tool life
- Steel injection tooling: highest upfront cost, lowest unit cost and best repeatability at volume
- Sheet metal with paint or powder coat: for structural or industrial-looking panels
- Urethane casting or 3D printing: for prototypes and the first pilot units
A common pattern is to bridge from a low-cost route during pilot and early fleet deployment to hard tooling once the design and demand are stable. The tooling glossary entry covers ownership and maintenance terms.
Core manufacturing processes
- Sheet metal fabrication, welding and powder coating of the frame
- Wire harness production, usually at a specialist supplier; harness faults are a frequent source of field failures
- PCB assembly for power distribution and motor control boards, often with conformal coating
- Battery pack assembly at the pack maker, with cell-level traceability
- Station-based final assembly with torque control and a serial record for each major module: battery, motors, sensors and compute
- Calibration of sensor positions relative to each other and to the wheels, stored per unit
- End-of-line testing on a drive track: obstacle and cliff detection, emergency stop, docking and charging, display, audio and network
- Burn-in and a final inspection before crating
Testing and validation: EVT, DVT and PVT
EVT integrates the subsystems: drive and navigation performance, battery capacity and thermal behavior, compute load and heat, and early EMC scans, since motors and switching supplies are strong noise sources.
DVT tests the robot against its operating environment and safety case:
- Endurance driving over cumulative distance, door thresholds, ramps and the floor types of target venues
- Bumper and collision tests, stopping distances and speed limits near people
- Battery abuse and thermal tests at pack and system level
- Exposure to cleaning chemicals and liquids, especially for cleaning and food-delivery robots
- Vibration, shock, EMC and ESD testing
- Verification of every safety function in the safety concept
- Field pilots in real venues, with failure data feeding design changes
PVT proves the production flow: station balance, calibration time, test coverage, crating and the service kit. The pilot production run guide covers how to plan those builds.
Design for service and fleet support
Service robots are maintained where they work, often by technicians who did not build them. Several decisions that make field service practical are made on the production line:
- Define field-replaceable modules, such as the battery, drive modules, LiDAR, compute and bumpers, and a target time to swap each one
- Use keyed connectors at module boundaries instead of spliced or soldered harness joints
- Label every replaceable module with a serial number and revision, and let the software read them where possible
- Record which module revisions are in each robot, so an engineering change can be targeted at the affected units
- Size spare-parts stock from DVT and pilot failure data, and hold it near the fleet
- Write repair and retest procedures during PVT, reusing factory test steps where you can
Safety and certification
Which standards apply depends on the robot’s task, environment and markets. Agree the list with a notified body or test laboratory before DVT.
| Area | Typical requirements |
|---|---|
| EU machinery | The Machinery Directive, being replaced by the Machinery Regulation from January 2027, which adds explicit requirements for autonomous mobile machinery |
| Robot and functional safety | ISO 13482, first written for personal care robots and revised to cover service robots in personal and commercial settings; ISO 13849-1 or IEC 61508 for safety-related control functions; in North America, UL 3300 for service robots and UL 3100 for automated mobile platforms |
| Radio and EMC | FCC Part 15 in the US and CE under the Radio Equipment Directive in the EU, with EMC requirements for the whole machine |
| Batteries | UN 38.3 and dangerous-goods rules for transport; the EU Battery Regulation |
| Lasers | Classification of LiDAR and any other laser sources under IEC 60825-1 |
| Materials | RoHS, REACH and WEEE in the EU |
Robots for factories and warehouses usually fall under industrial mobile robot standards instead, such as ISO 3691-4 and, in North America, the R15.08 series. Business customers also often ask for testing by a nationally recognized laboratory in North America, even where no law requires it.
What drives the cost
- Sensors and compute: LiDAR, cameras and processing modules
- Battery pack: cells, battery management and pack certification
- Drive system: motors, gearboxes and wheels
- Covers and tooling: the route chosen above sets both upfront and unit cost
- Labor: assembly, calibration and test hours per robot
- Freight: crated robots and dangerous-goods shipping
- Certification: safety assessment of a complex machine can be a significant line item
- Field service: spares, repairs and software support over the fleet’s life
What to ask a manufacturing partner
- Which electromechanical box builds of similar size and volume are running now, and can we walk the line and the drive-test area?
- Who manages the sub-tier suppliers for harnesses, sheet metal and the battery pack? The turnkey vs consignment model should be explicit.
- Who designs and owns the calibration and end-of-line test fixtures?
- How are serial numbers of major modules recorded against each robot?
- How are engineering changes introduced during ramp-up, and how will fielded robots be updated?
- Where will drive tests and burn-in happen, and how many robots can run at once?
Common mistakes
- Cutting steel tools for covers before the design and the fleet feedback are stable
- Leaving the safety concept to the certification stage, when it should shape the design from EVT
- Leaving harness design and routing to the assembler without a specification
- Designing a robot whose wheel motor or battery cannot be replaced without removing every cover
- Forgetting that the charging dock is its own product, with its own test and certification
- Running field pilots after DVT, when their findings can no longer shape the design
Where Zefinity helps
Service robot programs succeed or stall on early decisions: architecture, supplier structure, tooling route and the safety scope. Our Develop service covers manufacturing readiness assessments, supply chain strategy and access to engineering resources across the network, so those decisions are made before suppliers quote. Related robotics and automation topics are covered under industrial and robotics.
Frequently asked questions
What volume makes hard injection molds worthwhile for robot covers?
There is no universal break-even. It depends on part size, complexity, finish and the cost gap between processes at your volume. Get quotes for at least two routes, such as reaction injection molding or aluminum tooling against steel tooling, and compare total cost over the forecast. Design stability matters as much as volume: changing a large steel mold is slow and expensive.
How are service robots shipped with large lithium battery packs?
Lithium-ion packs are dangerous goods for transport, and packs above 100 Wh are fully regulated, with strict limits for air freight. Robots usually ship by sea with dangerous-goods documentation, a UN 38.3 test summary for the pack and packaging that meets the rules. Some programs ship packs separately from the robot; plan the route with the forwarder before PVT.
Should final assembly happen at the same factory as the electronics?
Not necessarily. Robot final assembly needs floor space, drive-test areas and mechanical skills that many electronics factories lack, while specialist box-build assemblers may buy in PCB assemblies. What matters is clear responsibility for the finished robot, controlled interfaces between suppliers and one traceability record across them.