Background
The customer is a Tier-1 automotive parts manufacturer in North China operating a 24-meter AS/RS. The system processes roughly 1,800 inbound and 1,500 outbound pallets per day using stacker cranes and AGVs. Loads consist of metal totes, with single-pallet weights of 700–900 kg.
Challenges
- Insufficient racking-load capacity on standard pallets led to excessive mid-span deflection.
- AGV stability issues caused by low base rigidity and minor pallet rocking.
- Tight dimensional tolerance required for AS/RS alignment and error-free handling.
Solution
1. Reinforced pallet design
- 1200×1000 mm 3-runner pallets with three steel reinforcements.
- One-piece injection-molded high-stiffness material with controlled tolerances.
- Strengthened fork-entry geometry for stable stacker-crane handling.
2. Racking-load and beam spacing matching
- Calculated racking load using 1000 mm beam spacing as baseline.
- Target racking load: 1000 kg with a 1.2 safety factor.
- Optimized load distribution to prevent off-center placement.
3. AGV compatibility tuning
- Bottom flatness controlled within ±2 mm.
- Added guide blocks at AGV transfer points for consistent fork angles.
- Introduced incoming QC standards to maintain batch consistency.
Results (first 3 months)
- 60% reduction in stacker-crane alarms due to improved pallet stability.
- ~10% faster picking and replenishment cycles from smoother AGV travel.
- Beam deflection kept within specification, eliminating previous over-limit incidents.
- Batch consistency stabilized and handling errors were largely eliminated.
Lessons for peers
- In high-bay systems, racking load is the key metric, not just dynamic load.
- AS/RS and AGV operations demand tight tolerances—control flatness and consistency at the pallet level.
- Load placement matters; off-center loads amplify deflection and alarms.
For high-bay projects, early pallet selection and load validation significantly reduce operational risk and long-term maintenance cost.
