Self-driving yard trucks are autonomous vehicles that move trailers around warehouses, distribution centers, ports, and factory yards. They handle short, repetitive trips such as moving a trailer from a dock door to a parking spot or inspection area. These systems matter because yard moves can create bottlenecks, safety risks, and delays even when long-haul transportation is well planned.
Automation can improve timing, reduce idle time, and make yard operations easier to monitor.
Key Facts
- Average speed is v = d/t, where d is distance traveled and t is time.
- Stopping distance can be estimated by d = v^2/(2a), where a is the braking deceleration.
- A yard truck localization system often combines GPS, lidar, cameras, radar, and wheel odometry.
- Safe following time can be estimated by gap time = distance gap/speed.
- Throughput can be estimated by trailers per hour = 60/cycle time in minutes.
- Autonomous yard systems use geofenced routes, obstacle detection, path planning, and fleet scheduling software.
Vocabulary
- Autonomous yard truck
- A self-driving vehicle designed to move semi-trailers within a controlled logistics yard.
- Lidar
- A sensing technology that measures distances by sending laser pulses and timing their reflections.
- Geofence
- A virtual boundary that limits where an autonomous vehicle is allowed to operate.
- Path planning
- The process of computing a safe and efficient route for a vehicle from its current position to a target location.
- Trailer spotting
- The task of positioning a trailer at a dock door, parking space, or staging area.
Common Mistakes to Avoid
- Assuming autonomy means no supervision is needed. Yard trucks often operate under human monitoring, safety rules, remote assistance, and controlled operating zones.
- Ignoring braking distance when planning routes. A heavy yard truck and trailer may need much more distance to stop than a small vehicle, especially on wet pavement.
- Treating GPS as perfectly accurate. Warehouses, trailers, and metal structures can block or reflect signals, so systems usually combine GPS with lidar, cameras, radar, and maps.
- Counting only driving time in a cycle estimate. Coupling, uncoupling, checking clearances, waiting for dock availability, and safety pauses can dominate the total cycle time.
Practice Questions
- 1 A self-driving yard truck travels 360 m from a staging area to a dock at an average speed of 6 m/s. How long does the trip take in seconds and in minutes?
- 2 A yard truck completes one trailer move every 8 minutes, including coupling, travel, and uncoupling. How many trailer moves can one truck complete in a 6 hour shift?
- 3 Explain why an autonomous yard truck should use both sensors and a digital yard map rather than relying on only one source of information.