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Operation

Theory of Operation​

The PowerHive system is essentially an automated battery reload system with managed charge profiles for batteries in the system. It can store and reload multiple battery voltages and sizes as needed and maintain the appropriate number of batteries in a “ready” state at any given time. It is intended to be a system that requires very minimal operator involvement and one that will eliminate the operator from decisions around which battery to deploy and how to do it. The operator only needs to stand on a pad and press a button, then wait for the system to unload and reload the best battery for the vehicle.

In addition to the battery reload “Hive,” the PowerHive system includes a “Cradle” that is used in the vehicle as a counterweight and electrical interface for the battery. The cradle contains some monitoring and connection hardware to disconnect the power from the vehicle in the event of a battery fault and displays the current State of Charge of the battery.

Batteries are designed to be of minimal size and weight so as to be easily moved from the forklift to the charging racks and back using the robot arm. Maintenance is minimal with the batteries and user-serviceable parts are located on the outside of the battery, away from the module stacks inside the enclosure. Battery packs are UL 2580 rated for safety.

Diagrams and Terminology​

It is important that all operators are familiar with this section in order to ensure safe and smooth operation of the PowerHive system. Additionally, knowing the correct terminology for parts of the system will ensure proper understanding of the manual and encourage accurate communication between operators and service technicians.

Definitions​

Battery Pack: A lithium battery containing cells, BMS, communication board, contactor, fuse, and cooling and heating system. BDI: Battery Discharge Indicator Cradle: The housing that stays in a vehicle in which a battery is loaded. Docking Light: A vertical light bar located at the top of the opening to the PowerHive Cell. The light will turn green when a battery in the hallway is in a swapable location. E-Stop: Emergency Stop button. Used to halt all PowerHive system operations. “Go” Button: Physical button used for triggering tasks and resetting errors. HMI: Also known as the Human / Machine Interface. Contains the buttons and touchscreen used for interacting with the PowerHive system. Pressure Pad: A black mat that detects the presence of an operator. Operators must remain on the pressure pad throughout the entirety of a swap. SOC: State of Charge

PowerHive Layout / Terminology​

Figure 2: System Overview

HMI Overview​

Figure 3: Human Machine Interface - HMI

For instructions about using the HMI and the available options, see the dedicated manual entitled, “HMI Manual.”

Completing a Battery Reload​

Parking the Forklift​

  1. As you approach the PowerHive, perform a visible check to make sure there are no obstructions in the hallway.

  2. Pull the truck into the hallway such that the battery is on the robot side of the hallway.

    • a. In most cases the ROBOT should be on your RIGHT side when parking.

  3. As you park, utilize the docking light located above the robot cell opening.

    • a. Pull in slowly and parallel to the hallway

    • b. When the docking light turns green , stop the truck and apply the parking brake.

  4. Complete site-specific steps for preparing the truck for a swap.

    • a. Some trucks require lifting of the seat before the swap can occur.

    • b. Some trucks require lifting the battery retention bracket before a swap.

  5. The system is programmed to complete any ongoing “idle” task when a truck is detected, then go to “home position” to wait for a swap to be initiated.

  6. Walk to (and stand on) the pressure pad located at the base of the HMI.

Initiating the Reload​

  1. While standing on the pressure pad, perform a visual check of the hallway and robot cell. Ensure there are no people or other obstruction present in the hallway or cell.

  2. After the visible check has been completed, wait for the green Go Button to begin flashing.

    • a. If the green light does not start flashing, the system may be finishing an “idle

task” such as moving or scanning a battery in the racks. This can take as much as 30s to complete in some rare cases.

  • b. If the Docking Light is green, the system is aware of the forklift and will eventually go to the home position to prepare for a swap.
  1. Press the green flashing Go Button to initiate the swap.

Notes:​

If the system detects that a person is visible in the cell or hallway the user will be informed via the HMI to perform a second check of the hallway and cell to ensure there are no people present.

If the system detects that the current truck needs its seat raised to perform the swap, it will notify the user to lift the seat and then reinitiate the swap.

During the Reload​

  1. During the swap the HMI will display the current and completed steps.

    • a. A green bubble next to a step means that the step has been completed. b. Yellow means the step is in progress.

    • c. Red means a step has failed.

  2. Stay on the Pressure Pad

    • a. If you leave the pad, a 5 second warning timer starts and the HMI will begin beeping.

    • b. Staying off the pad for more than 5 seconds will result in a pause in the swap process until you return to the pad.

E-Stop:​

Throughout the swap the operator should be aware of the robot’s actions. If necessary due to a collision or other dangerous malfunction of the system, the operator should quickly press the Emergency Stop button and then move away to a safe location.

  • a. Inform a supervisor immediately.

  • b. Contact your service department for assistance.

Finishing the Reload​

  1. After a reload has finished, the HMI will inform the operator and request you return to your truck.

  2. At this time, return to your truck and pull out of the hallway. This will make the system available to the next driver in need of a swap.

    • a. Notice the red lights on the floor will change from blocking out the hallway, to blocking out the robot area – this is a good indication for you to return to your forklift.

    • b. Flashing red lights on the floor indicate that a light curtain has been tripped and should be corrected before leaving the area.

      • i. Stand on the pad and pressing the “Go Button”

Important Notes​

  1. Before leaving the hallway, double check that the red light on the floor between the hallway and robot areas is SOLID RED (not flashing).

    • a. This indicates that the robot is ready to complete idle tasks and will work properly when the next person pulls in for a swap.

    • b. On some occasions, an operator may unintentionally trip this light curtain when lowering their seat or leaning over the edge of their seat while in the forklift.

    • c. If the light on the floor is flashing, go to the HMI and press the green button to reset the system before leaving the area.

Troubleshooting​

Emergency Stop Faults​

Floor Scanner or Light Curtain Fault​

  • 4.4.3 Non-Resettable Fault