RGV-type conveyor line for small-batch product assembly

This RGV-based assembly line uses a single center-mounted conveyor-equipped shuttle to carry standardized pallets between compact side transfer stations. Modular aluminum stations can be quickly swapped or extended, while RFID routing lets mixed small-batch products follow configurable paths. The RGV travels on a low-profile rail, docks within ±0.5 mm, and exchanges pallets in seconds; safety scanners and edges protect operators. The layout needs only one-third the floor space of a slat-chain line, supports 30-180 s takt, and is ready for MES and robot docking.

✅ 1. System Structure & Layout Logic

1.1 System Components

• RGV (Rail Guided Vehicle): One unit, equipped with行走 (travel), 定位 (positioning), and 托盘输送 (pallet conveying) functions.
• Side Transfer Stations: Symmetrically arranged on both sides for manual operations or automatic docking.
• Pallet System: Standardized pallets compatible with various product fixtures.
• Control System: PLC + sensors + RFID, supporting flexible process routing.
• Safety System: Laser scanner + safety edges + emergency stops, meeting PLd safety level.

1.2 Layout Logic

• The RGV travels along a central rail, transferring pallets between stations.
• Each side has multiple independent transfer stations, forming workstations.
• Operators or equipment work on pallets at the stations; RGV handles scheduling.
• Supports flexible routing: skipping stations, returning pallets, parallel paths, etc.

✅ 2. RGV Design (Center Conveyor Type)

2.1 Travel Mechanism

• Drive: Dual-wheel differential drive, servo motor + gearbox, adjustable speed (0.1–0.5 m/s).
• Guidance: Single rail + side guide rollers for smooth travel.
• Positioning: Barcode/QR code + servo control, repeatability ±0.5 mm.
• Power Supply: Conductor rail or battery-powered (optional), supports continuous operation.

2.2 Onboard Conveyor

• Type: Dual-chain / timing belt / motorized rollers, selected based on pallet weight/size.
• Width: Matches standard pallets (e.g., 400 mm).
• Speed: 0.1–0.3 m/s, synchronized with transfer stations.
• Positioning: Lift-pin mechanism to lock pallet on RGV.

2.3 Control & Communication

• Controller: Onboard PLC or remote I/O, wireless Ethernet to main controller.
• Sensors:
• Pallet presence (photoelectric)
• Pin status (magnetic)
• Safety edge & laser scanner status
• ID System: RFID reader for pallet info, supports multi-product mixed flow.

✅ 3. Transfer Station Design (Side-Mounted)

3.1 Structure

• Frame: Industrial aluminum profile + sheet metal base, modular assembly.
• Top Type:
• Non-powered rollers (light load, manual push)
• Motorized rollers (medium load, automatic)
• Lift & transfer unit (heavy load or redirection needed)
• Height: Aligned with RGV (typically 750 mm) for smooth handoff.

3.2 Positioning & Docking

• Pin Hole: Matches RGV lift pin for accurate docking.
• Stopper: Pneumatic or spring stopper to prevent pallet drift.
• Sensors:
• Pallet-in-place detection
• Operation-complete button or barcode scan
• Optional safety light curtain

3.3 Quick Changeover Support

• Tabletop with standard hole grid (e.g., 50×50 mm) for fast fixture adjustment.
• Whole station can be swapped in <5 minutes.
• Fixture sub-plate detachable from pallet; only sub-plate needs changing for new product.

✅ 4. Pallet & Fixture System

4.1 Pallet Structure

• Size: Standardized, e.g., 400×600 mm, 12 mm thick.
• Material: Aluminum alloy or engineered plastic, lightweight and strong.
• Interfaces:
• Corner bushings for RGV/station pins
• RFID tag slot underneath
• Mounting hole grid (M6 threaded or dowel holes)

4.2 Fixture Design

• Sub-plate: 300×400 mm replaceable fixture plate, hand-screw mounted.
• Clamping: Manual quick clamps, pneumatic grippers, magnets, etc.
• Compatibility: Multi-product pallets; only sub-plate changed for new product.

✅ 5. Control & Information System

5.1 Control Architecture

Level	Devices	Function
Device	RFID, servo, I/O	Real-time sensing & actuation
Control	PLC + HMI	Routing, RGV control, station management
Info	MES interface (optional)	Work order, routing, traceability

5.2 Process Flow Example (Single-Piece Flow)

1. Operator loads pallet at load station → presses “Call”.
2. RGV arrives → pallet transfers onto RGV → lift pins lock.
3. RGV moves to next station per routing table.
4. After operation, operator presses “Release”.
5. RGV returns, picks up pallet → continues.
6. At last station, RGV sends pallet to unload station.
7. Empty pallet can be returned manually or via optional return line.

5.3 Multi-Product Mixed Flow

• Each pallet RFID contains: product type, routing, quality status.
• RGV reads info and auto-selects path.
• Supports skipping, rework, parallel paths.
• Changeover: swap fixture sub-plate and select new product on HMI.

✅ 6. Safety & Ergonomics

6.1 Safety Systems

• Laser Scanner: 270° detection, zoned减速/停止 (slowdown/stop).
• Safety Edges: On RGV, trigger immediate stop.
• E-Stops: On RGV and key stations.
• Safety PLC: Handles all safety signals, PLd level.
• Audible/Visual Alarms: Indicate RGV status/faults.

6.2 Ergonomics

• Table height 750 mm, suitable for Asian operators.
• Buttons/scanner within arm’s reach, no twisting.
• Pallet flow direction consistent, minimal turning.
• Optional LED lighting and fan on station frame.

✅ 7. Expansion & Upgrade Options

Direction	Description
Add Stations	Rail extendable; RGV program auto-scales routing
Auto Load/Unload	Dock SCARA or 6-axis robot to station
Pallet Return Line	Add empty-pallet return conveyor, closed loop
MES Integration	Real-time upload of operation & quality data
Dual RGV	Add second RGV for higher throughput (<60 s takt)

✅ 8. Summary: Key Advantages

Feature	Benefit
High Flexibility	Multi-product mixed flow, configurable routing, fast changeover
Space-Saving	Line length ~1/3 of traditional slat chain, fits small workshops
Easy Expansion	Modular stations, scalable control & rail
Controllable Investment	Single RGV + modular stations, pay-as-you-grow
Digital-Ready	RFID + MES interface, future-proof for Industry 4.0