SOLUTION

  • Order Generation

    Natural Navigation leverages Laser Range Sensors to identify environmental landmarks such as walls and fixed structures. The AGV’s position is continuously updated using encoder feedback, which tracks wheel rotations, along with real-time sensor data from the environment. This ensures that localization is maintained continuously during operation, keeping the navigation system active at all times.

    Transport activities in the AGV system are treated as orders. Typically, an order defines a transport task between two pre-configured positions or stations. Once initiated, the order triggers a sequence of predefined transport operations configured by the system designer within the AGV Control System. Transport orders are usually auto-generated using one of the following methods:

    A. Push-button or Sensor
    Activating a push-button or sensor input triggers a transport request. These input devices are generally wired directly to the AGV control system or interfaced via an I/O module.
    B. Host System
    An integrated host system such as MES (Manufacturing Execution System), WMS (Warehouse Management System), or ERP (Enterprise Resource Planning) can generate transport orders. These systems communicate with the AGV Control System via standard industrial communication protocols over the network to initiate transport sequences.

  • Order Allocation

    After an order is generated, the AGV control system identifies the most suitable vehicle to execute the transport task and calculates the most efficient route to the destination. In systems with multiple vehicle types, the control system evaluates the vehicle type best suited to the specific requirements of the order. If no compatible or available vehicle is found at that moment, the order is placed into a pending queue until resources become available. In cases where multiple suitable and available vehicles exist, the vehicle closest to the pick-up station is selected to ensure minimal response time.

  • Order Completion

    Upon successful completion of a transport task, the AGV sends a confirmation message to the AGV Control System. If required, the AGV Control System then forwards the order completion status to the higher-level process control system. This transport sequence, from order generation to order completion, continues cyclically while the system is operational.

    Exception Handling

    In case of unexpected scenarios where an order cannot be completed as planned, the AGV Control System is equipped to manage a wide range of exceptions during the transport process. For instance, if an order is cancelled mid-execution, the control system terminates the task immediately and instructs the AGV to perform a pre-programmed fallback action specific to the case.

  • Traffic Management

    To ensure optimal traffic flow, layout design should ideally incorporate two-way paths to minimize the risk of collisions between AGVs. In situations where vehicles must share a single-lane segment or intersection, the AGV control system is responsible for dynamically deciding which vehicle receives right-of-way. This mechanism is referred to as traffic management.

    Driving Path Allocation
    Upon receiving a movement command, the AGV control system allocates exclusive path segments to the vehicle and marks them as occupied to prevent path conflicts with other AGVs. This reservation-based method ensures safe and collision-free navigation.
    Deadlock Resolution
    If multiple AGVs obstruct one another’s paths, a deadlock condition may arise. When such scenarios are detected, the AGV control system automatically attempts to resolve them by rerouting one or more vehicles, restoring traffic flow and system efficiency.

  • Traffic Rules

    To prevent traffic congestion, traffic rules should be established during the system design phase. The following are standard traffic rules typically applied in single-lane paths or intersection zones. However, strict adherence is not mandatory, as systems can be optimized dynamically based on operating conditions and system-specific requirements.

    Driving Priority Assignment in Traffic Section
    • Vehicles that arrive first are given driving priority.
    • Vehicles assigned to a goods transport task are prioritized.
    • Vehicles currently executing a transport order are given priority.
    • Vehicles in the process of loading goods are prioritized.
    • Vehicles transporting goods with higher assigned priority are granted right of way.

  • General Data Flow of AGV system

    The figure below illustrates the data flow between various components of the AGV system, including the interface-level communication with the Process Control System. Typically, wireless communication protocols are employed for real-time data exchange between the AGV Control System and the autonomous vehicles. Conversely, Ethernet connections are utilized for stable and high-speed data transmission between the AGV Control System and external control systems.

  • Inteface with Eqiupment Controller

    In certain scenarios, the AGV system must interface directly with factory equipment such as automatic doors, conveyors, and other operational units. Digital input signals are typically used to reflect the current operational status of the equipment, while the AGV Control System issues conditional commands via digital outputs to trigger or modify equipment behavior.

    • Interface for Vehicle Driving
      When equipment is located along the AGV’s path, the AGV Control System communicates with it to ensure the path is made accessible for vehicle movement.
      Once the AGV has cleared the area, the control system re-initiates communication to cancel the request and return the equipment to its original state.
    • Interface for Load Handling
      When load handling operations are executed in coordination with station equipment, the AGV Control System performs a handshake protocol to manage sequential load handling tasks.
      In some implementations, the AGV can also directly initiate communication with the equipment for autonomous load handling.
    • Interface for Safety
      To avoid potential collisions between the AGV and adjacent equipment during navigation or handling operations, the AGV Control System issues a stop request to temporarily halt nearby equipment.
      This safety interface remains active until the AGV exits the operational area, ensuring safe coexistence of mobile and stationary systems.

  • Interface with Other Control Systems

    In an automated factory environment, there may be multiple control systems operating alongside the AGV Control System. To ensure seamless coordination (for tasks such as order generation, load handling, or safety) AGV systems often need to interface with these other control units. There is no single standard method for integration; the interface approach is selected based on the specific communication requirements.

    A. Database Sharing
    When interfacing via a database, a designated table is created to facilitate mutual sharing of real-time operational data. Each system periodically queries the database to detect updates made by the other system, enabling indirect synchronization through scheduled data polling.
    B. Message Transmission
    This interface approach allows systems to exchange data through structured messages based on a predefined data protocol. Messages are transmitted either upon the occurrence of specific events or at regular intervals, ensuring timely delivery of status updates and commands.
    C. Hard-Wired I/O
    Direct digital input/output (I/O) signals can also be employed for interfacing between systems. Because the systems are physically connected via I/O devices, the data exchange is immediate and deterministic, making this method suitable for time-sensitive operations.