AUTOMATED STORAGE/RETRIEVAL SYSTEMS
Figure 1: Destamat 1224 Major Components
The Storage Control System (SCS):
The ULC determines bin location and directs the SRM movement through the SCS, in the form of missions. When a mission is complete, the SCS communicates this to the ULC. The ULC notifies the Strategic Inventory Management System (SIMS) of the pallet location. Through the use of the system, product inventory is maintained.
This section provides an overview of how pallets are received, stored, and transferred into the rack for storage and picking.
Figure 4: Typical Storage and Retrieval Machine Input/Output Area
Input pallet position.
Output pallet position.
BK-25 Pallet Conveyor
Chain-driven conveyor used to move pallets. This conveyor is located at:
Automated Guided Vehicle (AGV)
Unmanned guided vehicle used to move a pallet load from one location to another.
Area where the pallet loads are profiled (weight and dimension).
Pallet tag bar code is scanned.
AGV ID is scanned.
Bar code information is provided to the ULC for coupling the pallet load to the AGV.
Area where a rejected pallet is taken for corrective action before being re-inducted into the system.
Personnel in the receiving area take delivery and palletize product destined for the Destamat 1224's located in the hi-rise warehouse. The pallet is inspected for damage, the load is positioned on the pallet to conform to proper configuration, and a label is applied to the load. The pallet loads are then placed on the BK-25 conveyor, which indexes the load forward to the AGV pick-up location. When the load reaches the pick-up point a signal is sent to the ULC, via a photo eye. The ULC then schedules an AGV to pick up the load.
The AGV picks up the load from the BK-25 conveyor and proceeds to the sizing station.
At the sizing station:
If the load is within the preset parameters and an expected receipt is on file, the AGV proceeds to the assigned SRM aisle. If the load is not within the parameters or there is no expected receipt on file, the load is sent to the pallet hospital. After corrective actions are completed, the load is re-introduced into the system through the Strategic Inventory Management System (SIMS).
The AGV takes the pallet to BK-25 input conveyor at one of eight aisles. If an expected receipt is on file, the load is stored in a location. The load is moved to the outbound (AP) conveyor if:
The load is them transported by AGV to the pallet hospital and SIMS is notified of the unknown load.
The load is positioned for SRM pickup at the SRM input position (EP).
The BK-25 lifting table rises, creating a fork window for the SRM to pick up the load. When the load blocks the photocell on the input conveyor, the conveyor control sends the load present information to the ULC.
When the load is in position and the lift table is up, the BK-25 conveyor Programmable Logic Controller (PLC) turns on an output. The output is wired to the SRM and indicates that it is safe to pick up the pallet.
The SRM must be in automatic mode and the Storage Control System (SCS) computer set for remote operation before the ULC will issue a mission command via the Ethernet. This mission indicates that the SRM can pick up the load and move it to the storage location selected by the ULC. The SCS will execute the mission upon receipt from the ULC.
The SRM moves horizontally and vertically to reach the input position. When the SRM arrives at the input position, the SRM will verify that the signal from the BK-25 conveyor PLC is available indicating it is safe to pick up the pallet.
When the safe signal is recognized, the Load Handling Device (LHD) extends below the pallet, lifts it to a bin high position and then retracts back to the center position. When the LHD moves off-center for the pick up, the LHD centered signal to the conveyor controls is turned off and prevents the BK-25 conveyor from indexing the next load forward.
During the lift to the bin high position, the SRM checks the weight of the load to insure it does not exceed the 2000 pound weight limit, If the pallet weight exceeds 2000 pounds, the pick up cycle stops and a fault is issued to the ULC. Manual intervention is required to correct the fault and remove the overweight load from the system.
If the load is less than the 2000 pound weight limit, the LHD retracts to the center position with the pallet on board. When the LHD returns to center, the LHD centered signal turns back on indicating that the SRM input position on the inbound conveyor is available for the next load.
If the load destination is a pick face location, SIMS will direct the ULC through the expected receipt, where to place the load. If the load is designated for a storage location through the expected receipt, the ULC will determine the storage location of the load.
Once the SRM has picked up a pallet load and no fault has occurred, it moves to the assigned location. Before the LHD cycles, the SRM checks the location to verify that it is empty.
If the location is empty, the LHD will extend, deposit the pallet, and retract to center.
If the location is occupied, a Full Bin Logical Error is generated and sent to the ULC. When a Full Bin Logical Error is identified, the ULC directs the SRM to store the load into an alternative location and then notifies SIMS. After the pallet has been deposited into a location and the LHD has returned to center, the SCS sends a mission complete to the ULC and waits for its next mission.
When a load is to be removed from the system, SIMS sends an expected receipt to the ULC.
The ULC sends a mission to the SRM to remove the load from a location and deposit the load at the AP. The SRM travels to the location, picks up the load, and travels to the AP. At the AP the forks will extend and deposit the load. When the forks are returned to center a mission complete message is sent to the ULC. The SRM is now ready for the next mission.
When the load arrives at the AP the load is indexed forward to the AGV pick up position.
When the load reaches the AGV pick up location the ULC registers a pick up call and assigns an AGV to pick up the load. The assigned AGV travels to the pick up point and picks up the load.
The AGV then travels to the required destination and deposits the load.
Additional system functions:
This section describes safety precautions that should be followed before, during and after maintenance and troubleshooting tasks.
The rail-guided handling equipment is built according to the latest state-of-the-art engineering, the currently applicable safety rules, and has passed manufacturer's safety testing.
The rail-guided handling equipment has been delivered to the owner by Siemens Dematic in technically perfect condition and has passed an acceptance test.
The documentation supplied by Siemens Dematic concerning operation and maintenance of the rail-guided handling equipment must be adhered to during equipment operation. Siemens Dematic is not liable for damage attributable to incorrect handling or non-compliance with the guidelines governing operation and maintenance.
Changes to the factory settings made by Siemens Dematic may only be performed after the express written permission of the manufacturer has been granted.
It must be ensured at all times that the rail-guided handling machines are only operated when in perfect working order, that the operating personnel are aware of the hazards, and that it is operated in accordance with its intended purpose.
In addition to the initial training of personnel (when equipment is first placed into operation), continuous training is required on a regularly scheduled basis. The purpose of continuous training is to reinforce the importance of safe work practices by ALL employees, including new hires and transfers working with or around the equipment.
The customer is responsible to provide training for employees to ensure that they are knowledgeable in the safe operation and maintenance practices of the equipment.
When performing maintenance work, all personnel must strictly comply with the regulations governing the handling of the switch key system.
A single switch key is assigned to each SRM in the switch key system. If several SRMs are used in an installation, each SRM has its own switch key with a different lock.
The switch key of an SRM operates the following locks:
Spare keys must be kept under lock and key and must not be accessible under normal circumstances.
The switch keys are used to determine the mode of operation (automatic, manual or emergency) and to turn off the SRM. The SRM must be switched off and the switch key removed before switching to a different mode of operation.
The access doors to the rack aisles are fitted with door contacts. The SRM is automatically switched off when an aisle door is opened.
Authorized personnel must comply with the following rules when handling the switch keys:
The following procedures must be followed prior to Manual Operation or Maintenance of the equipment. These steps apply to one or multiple SRM(s) depending on its application.
If the multiple SRMs are attached to a single SCS, follow these steps unless all SRMs on the SCS are to be serviced or shutdown.
After all of these steps have been completed for the desired SRMs, continue to the next section.
The primary purpose for a lockout/tagout procedure is to protect workers from injury caused by the unexpected energizing or start-up of equipment.
The rule requires that energy sources for equipment be turned off or disconnected, and that the switches are locked and labeled with a warning tag. This ensures that the equipment has been shut down for service or maintenance and will not reactivate while employees are working on it. The regulation defines that service and maintenance includes "lubrication, cleaning or unjamming of machines or equipment," among other things.
It is important to note that the lockout/tagout procedure is considered to be just one element of the control procedure for hazardous energy. The employer is responsible for providing procedures that include de-energizing of equipment, isolation of energy sources, verification that equipment has been de-energized, and complete diffusion of stored energy.
The standard requires an ongoing program of control procedures and employee training by the employer to ensure that the purpose and functions of energy controls are understood and applied. Lockout/tagout should take place before any service or maintenance work begins.
The service person who locks and tags a machine must be the one who unlocks the machine.
Never remove a lock or tag that is not yours.
Never lock or tag equipment for another person.
If a lock or tag is left on during a shift change, leave it in lockout/tagout condition. Assume the equipment is locked or tagged for a good reason. Contact your supervisor for further direction. If work is done in shifts and the work is not completed, the new shift employees should install their locks or tags while the existing shift is removing theirs. When possible, the new shift should install their locks before the existing shift removes theirs so nothing is ever unlocked.
Figure 10: OSHA Approved Lockout/Tagout Devices
Before beginning work, ensure that power is actually removed by checking various points to ground with a test meter. Although power to the device being serviced is removed, some points of the device may be energized due to interconnections with other equipment. Such areas are appropriately marked.
If maintenance must be performed with power in the ON or 1 position, be sure the following precautions are taken:
While working never forget that other pieces of equipment can be involved when a particular START or STOP pushbutton is pressed. Before energizing '''''ANY''''' element of the system, it is essential to:
The manual control mode can be selected in order to correct simple faults, such as overhanging goods, loads not picked up centrally or excessive loads, without having to deactivate the safety devices of the machine.
The manual control mode is started from the on-board control panel. Commands are provided by means of a control terminal. See the Operations Training Guide for more information.
The emergency control mode is activated from the on-board control panel. It is operated via operating elements located in/on the control cabinet.
The Interbus system is the communication system for control of the SRM. The Interbus collects all the input and output data of the SRM and sends this information to the co-processor. The Interbus has various devices arranged in series. When a fault within the Interbus occurs, the device that has malfunctioned is indicated at the SCS through the co-processor.
To troubleshoot the Interbus, the maintenance person must be able to identify the devices using the electrical drawings located in the Operation and Maintenance Manual.
Figure 11: Interbus (IBS) Assembly
When a fault occurs:
Preventive maintenance of the SRMs is critical for the safe and efficient operation of the units. This section assists the customer in administering a maintenance program and provides a sample PM schedule.
This section contains information on the following sections of the Operation and Maintenance Manual.
The following checks will be conducted prior to SRM start-up:
A table is provided for the correct torque specifications for all mechanical fasteners in the Operation and Maintenance Manual.
Follow the lubrication guide in the Operation and Maintenance Manual.
Dampen a clean lint-free rag with lubricant and wipe the vertical guide rail only as required to prevent rust. Remove any excessive oil using a dry lint-free rag.
The preventive maintenance checklist provides a list of all maintenance requirements for a major component and the time frame in which the maintenance should be conducted. The maintenance schedule is outlined in the following chart.
The catch device is a piece of safety equipment designed to mechanically stop the carriage in a free fall situation.
A speed governor is attached to the catch device through a cable which actuates a mechanical wedge located inside the catch device. The combination of the wedge and knurled roller is clamped against the guide rail to stop the carriage.
The catch device can be actuated by the following:
The catch device is the last line of defense for a free falling carriage. Maintenance of this device is crucial for proper operation. All maintenance procedures for the catch device must be performed every 1800 hours of operation. See the Operation and Maintenance Manual for preventive maintenance requirements.
The catch device must be overhauled every ten years in conjunction with the SRM overhaul.
After a catch device has been actuated the carriage is mechanically bound to the mast guide rail. Trying to lift the carriage with the motor will not release the catch device. The following procedure must be followed to release the catch device.
The following equipment will be needed for carriage ejection:
The following procedure is used to eject the carriage:
Figure 12: Carriage Ejection