Whew, second post and I am still standing.

This blog is dedicated to telling a real-time story from a front row-seat of a fully automated parking development. It will start with Concept move to Construction followed by Commissioning and end with Completion.

“The beginning of wisdom is a definition of terms.” – Socrates

If it was good enough for a 5th Century BC philosopher, it is good enough for me.

As with any industry jargon, terms and acronyms can at times be overwhelming. I would like to say that the automated parking is unique but that would be misleading at best and a complete fabrication of the truth. So below is a set of terms that we have repurposed, developed and refined for a fully automated parking structure.


Short List Quick Definition:


  • Conveyor –  Series of rollers that transfer pallets  between subsystems. This is a part of Shuttle, Lift or Cell Subsystem


  • Lift – vertical movement of a pallet; the automotive industry also uses the term VDL which stands for Variable speed Drive Lift. A drive is device that controls the electricity flow to a motor and thus controls speed, direction and torque.


  • Load Bay – location where vehicles are deposited and returned


  • Pallet – indivisible platform that a vehicles rests upon. The pallet is conveyed between subsystems such as Lift, Shuttle, Turn Table, and Cell. A pallet normally resides in a cell or during a transaction it may reside temporarily on a Shuttle, Lift or in a Load Bay.


  • Shuttle –  horizontal movement of a pallet


  • Shuttle Lane – defined area where the shuttle travels


  • Tandem Cell – enumerated, fixed storage location for two pallets


  • Turntable – rotating movement of a pallet



The relationship of most of these subsystems is shown below:

Chapter 2 - IMG 1


System Physical Relationship Diagram


Expanded List Extended Definitions – Reference Only


AutoParkit (API) System: is the infrastructure, mechanical, electrical, controls and software components that comprise an automated parking structure designed, installed and commissioned by AutoParkit. It is a modular system that can be customized for each installation base on site specific information. The major subsystems are: Lifts, Shuttles, Turn Table, Conveyors, Cells, Load Bays, Valet Station, Main Control Panel, Micro Data Center, Pallets, GarageFloor24™ .


Cell, Single – Single storage location. The Single Cell can be empty, ready (empty pallet), or full (pallet with a vehicle).

Chapter 2 - IMG 2

Figure 2.3  Three States of a Single Cell and Key


Cell, Tandem – Two cell locations side by side. The cell closest to the shuttle or lift is the front cell while the cell farthest from the shuttle or lift is the back cell. The Tandem Cell has 9 different states.

Chapter 2 - IMG 3

Figure 2.4 Nine States of the Tandem Cell


Cell, Triple – Three cell location side by side by side. The cell closest to the shuttle or lift is the front cell, the next one is the middle cell and finally the back cell. A Triple Cell has 27 different combinations. Some are theoretical and shall never occur in a normal operating API System but are show here for completeness.

Chapter 2 - IMG 4

Figure 2.5 Twenty-seven States of a Triple Cell


Cell, Non-Powered – Is a Single, Tandem or Triple Cell that has NO dedicated electric motor(s) to assist the move of the pallet via conveyor.

Chapter 2 - IMG 5


 The conveyors on these Non-Powered Cells are powered by a Parasitic Drive on the Shuttle or Lift. Vehicles move from the Shuttle to the front (Outer Cell) of a tandem cell.  As a second vehicle is loaded into a tandem cell, the front vehicle (Outer Vehicle) is transferred to the back (Inner Cell).


To retrieve the Inner Vehicle on a tandem cell, the Outer Vehicle must be moved first.  A buffer cell is used for the temporary storage of the Outer Vehicle while the Inner Vehicle is moved to the Load Bay for departure.



Cell, Powered – Is a Single, Tandem or Triple Cell that has dedicated electric motor(s) to assist the move of the pallet via conveyor.  Powered Cells are driven by a motorized conveyor.  There are three types of powered cells – Single, Tandem and Triple cells Two vehicles can be parked in a Tandem Cell by parking one at the front (Outer Cell) and one at the back (Inner Cell).  A Triple Cell allows for 3 vehicles. Three vehicles can be parked in a Triple Cell by parking one at the front (Outer Cell), one in the middle (Middle Cell) and one at the back (Inner Cell).  Vehicles move from the Shuttle or lift to the front (Outer Cell) of a tandem/triple cell.  As a second vehicle is loaded into a tandem cell, the front vehicle (Outer Vehicle) is transferred to the back (Inner Cell). For a Triple Cell the process is repeated.



Chapter 2 - IMG 6




To retrieve the Inner or Middle Vehicle, the Outer Vehicle must be moved first.  A buffer cell is used for the temporary storage of the Outer Vehicle while the Inner/Middle  Vehicle is moved to the Shuttle or Load Bay for departure.


Conveyor: A conveyor moves a pallet from subsystem to subsystem.


Cell to Cell

Cell to Shuttle

Cell to Lift

Cell to Turn Table

Shuttle to Cell

Shuttle to Lift

Shuttle to Turn Table

Lift to Cell

Lift to Shuttle

Lift to Turn Table

Conveyor to Shuttle

Conveyor to Lift


Driver – is a User who is operating the vehicle that is requesting to park in the API System or exiting the API System while operating a vehicle.


GarageFloor24™  –  System SCADA (Supervisory Control And Data Acquisition) software that executes on a local server in the MDC. GargeFloor24 also executes on a remote server.


Handicap Vehicle  – Any Vehicle that is equipped for a handicap driver.


Keyfob– A site specific RFID that contains the identification of the user and their associated vehicles. It is used for driver authentication.


Lane – The space between cells where a shuttle travels. A Lane may have multiple Shuttles assigned to it.


Level – A set of Cells on the same plane.  Level heights can vary due to vehicle heights. A level may or may not have a floor.


Lift –Vertical movement of a pallet between storage levels. During storage it lowers or elevates the car from the existing level to the designated level. If the lift is located in a Load Bay and it is not in use, the lift remains in the home position at the Load Bay with an empty pallet onboard, and the locking pins extended.

Chapter 2 - IMG 7


Top View Lift Position


Load Bay – Location in the API System where the vehicle is either (1) delivered by a user to the API System for storage [nose in] or (2) delivered by the API [nose out].  The Load Bay isolates people from the parking system.  Before a vehicle is automatically parked, the user must have exited the Load Bay via the security door, the garage door must be closed, the security doors must be closed, and the vehicle must fit within the maximum size envelope for the vehicle.  On departure, vehicles are returned by the automated parking system to the Load Bay.  The Load Bay shall have either a conveyor or a lift. The lift or conveyor may be equipped with a turntable.


Log – A collection of records kept on an aspect of the API System. The Logs shall be defined as follows: Alarm Log, Asset Management Log, Configuration Log[System Parameters, User Data], Control Log [Virtual Rack System], Engineering Log, Event Log, Maintenance Log, Performance Log, Project Log. These records kept shall be generated and visualized by GF24 and local HMI Screens. The Logs are locally stored on the System Server and the original data shall reside in the PLC located inside the MCP.


Main Control Panel (MCP) – overall control and safety supervision of the system


Micro Data Center (MDC)  – provides remote internet access, controls user interfaces and  provides system backup


Network Access Point (NAP) – strategically placed control panels containing LAN equipment and remote I/O connectivity for low voltage field devices.


Operator – Any person who is trained to manage an API System after a complete installation.


Overhead Door Controller (ODC) – drive/motor and controls for opening and closing of an overhead door


Pallet – Carrier of the vehicle or storage contents that has a fixed width, length, weight and storage capacity.


Shuttle –vertical movement of a pallet on the same level. Moves an empty pallet or a full pallet to an empty cell location and then loads the pallet and contents to the empty cell. Or positions itself to a full cell location and loads the pallet onto the shuttle for delivery to another cell on the same level or delivers pallet to a Lift, Load Bay, Conveyor, Turntable, etc. The Shuttle consists of a carriage that moves horizontally on rails. Power is delivered to the Shuttle via power rails.  The Shuttle has motorized rollers to move the vehicle off the Shuttle and into a cell or onto the Lift.  The Shuttle also has a parasitic drive motor that will engage the slave cells and drive the conveyor to transfer the vehicle off the Shuttle and into the slave cell.

Chapter 2 - IMG 8


Top View Shuttle Position


Site Specifics – All characteristics that are unique to the actual implementation of the API System. Although each system is built from the same core subsystems the arrangement and organization of these systems are unique to the implementation. However the subsystems employed shall follow the exact definition, interface and behavior from site to site.


Stacker – holds multiple pallets than can be dispensed or retained for temporary storage


Storage Rack – Is the collection of Cells that are organized in Levels and Lanes. The hierarchy shall be Level:





Supervisory Control Panel (SCP) – coordination of multiple MCPs (optional)


System Data – Refers to the sum total of the real-time information of the API System.


Traditional Parking – Parking Structures built above grade in a pre-cast or column basis with ramps, turn radius and end-user access. Including 24-7 lighting, POS, etc.


Total Retrieval Time – The elapsed time between when a user enters a parking structure and exits with their vehicle. Abbreviate (TrT)


Total Storage Time – The elapsed time between when a user initially drives into a parking structure and then leaves the parking structure after having the vehicle parked. Abbreviated (TsT)


Valet Station – A safe and secure location in the API System where a user requests retrieval services via Human Machine Interface (HMI) devices (e.g. touch screens, display screens, card or fob readers, point of sales (POS) systems, audio alarms, warning alarm lights). Users are allowed to be in the Valet Station at any time while waiting to pickup a vehicle and have full access to all HMI devices in that area.


User – Any person who requires and/or pays for the services provided by an API System. A user can also be referred to as a customer, tenant or driver. User, Customer, Tenant, Driver are all used interchangeably.


User Kiosk – location where users interact with system