Why an AGV needs a different sensor from a drone
An automated guided vehicle does not need range. It needs a reliable 0.1 to 5 m, several times per second, in a factory where the floor is grey, the pallets are brown and someone has just walked in front of the truck. The failure mode that stops a fleet is not “the sensor cannot see 200 m”; it is “the sensor reported a wall at 1.4 m because the return came off a reflective floor strip”.
Single-point laser distance sensors sit between ultrasonic and full 3D LiDAR in cost and complexity. They answer one question — how far is the nearest thing in this direction — but they answer it fast, in a tight beam, and without the cost of a scanning head. For AGV and AMR work that is often exactly the question the safety logic needs.
Modules used for AGV and AMR obstacle sensing
| Model | Published range | Price | Where it fits |
|---|---|---|---|
| LRF10VB | 0.05–9 m at 90% reflectivity; 0.05–5 m at 10% | $80 | Lowest-cost close-range guard; 940 nm, so the spot is invisible to people nearby |
| LRF22VB | 0.05–20 m at 90%; 0.05–10 m at 10% | $90 | Forward obstacle guard and dock alignment |
| LRF50VB | 0.05–50 m at 90%; 0.05–20 m at 10% | $140 | Longer approach zones, aisle entry |
| LRF50H | 0.05–50 m at 90%; 0.05–15 m at 10% | $160 | Industrial head with a 9–36 V DC supply — no separate 5 V rail |
| LRF200H | 0.05–200 m at 90%; 0.05–70 m at 10% | $250 | Vehicle-to-vehicle spacing in large yards |
| SPD1200N3 | 3–1,000 m | $94.5 | Cheap single-photon long range, but the 3 m floor rules it out as a close guard |
Notice the pattern: every module states two numbers, and the second one is what happens on a dark target. An AGV in a warehouse is surrounded by dark targets — shrink-wrap, black rubber, steel with a mill finish, and people in dark clothing. Plan against the low-reflectance column and the sensor will not surprise you on the shift where everything goes wrong at once.
What you actually wire
Most of these modules present a UART interface with a documented frame and checksum, and report distance in a documented unit — the H series reports centimetres. Three integration details decide whether the AGV behaves:
- Update rate against vehicle speed. At 1.5 m/s a vehicle covers 15 cm in 100 ms. A sensor sampling at 10 Hz gives you a 15 cm gap between two consecutive readings of a moving obstacle. Rangefinder update rate for moving platforms works through the arithmetic.
- Enable-pin behaviour at power-up. If the enable pin polarity is inverted, the vehicle starts with a sensor that reports nothing for a second — and the safety PLC cannot tell that apart from “clear path”. Polarity and wake time.
- Serial frame integrity. Checksums matter most in exactly the environment you are building for: motor drives, VFDs and 24 V contactors. Serial protocol frames and checksums.
Where a single-point sensor is not enough
A beam is a beam. It measures what it hits, and if the thing it hits is not the thing that will hit the vehicle, it reports a safe distance while the truck collides with a low pallet edge or a hanging strap. The honest architecture is layered: a 3D LiDAR or a safety laser scanner for the safety-rated envelope, plus one or more single-point modules for the functions that need a cheap, fast, deterministic answer — dock alignment, aisle end detection, gap measurement, load height.
If the requirement is a safety function certified to a category and performance level, a component module with a UART output is not that product. Use it where the system, not the sensor, carries the rating.
Next step
Send the vehicle speed, the required detection distance, the target materials on your floor and the supply rail available on the truck to tommy@erdimail.com, or use the sample request form. You will get a specific model recommendation and the conditions behind its range figure within one business day (Chengdu, UTC+8). Broader background: 905 nm rangefinder for AGV/AMR obstacle avoidance and the level and AGV sensing checklist.
Where two source documents for a model conflict, the model page states the conflict rather than choosing one value, and the current datasheet governs the order.