International Transportation (67) 2 | 2015 40 SCIENCE & RESEARCH Car Parking Automated parking systems - Operation and practical-experience Parking space, automated parking systems, planning and specifications Automated parking systems have been available in various forms since the 1920s. Nevertheless, the total parking capacity they provide remains limited. Due to the relatively satisfactory parking space supply, the-demand for automated parking is quite low in Germany. Approximately 10,000 parking spaces are provided in a total of 200 automated parking systems. Due to their mostly non-public use, their existence is not widely known. Far more parking spaces, for around 1.7 percent of the country’s total vehicle stock per January 1, 2015, are available in mechanical parking systems, which are not fully automated. Abroad, German manufacturers have also realized systems with higher numbers of parking spaces. The following article gives an overview of today’s operation and planning. Author: Ilja Irmscher A utomated parking systems are parking facilities with vehicletransfer systems that are capable of transferring incoming vehicles automatically to parking spaces. They are classified in the EAR 05 [1] and VDI 4466 [2] guidelines. Strictly speaking, automated parking systems are mechanical parking systems with automated and electronically controlled parking procedures that start and end at the interface of the transfer cabin. All that users are required to do is leave their vehicle in a transfer cabin and confirm that it has been left in a system-compatible condition (i.e. with the engine turned off, doors, windows and hatches shut, activated handbrake, gear settings in first or reverse gear for manual gear shift vehicles, and deactivated alarm system). Exiting the transfer cabin after the parking period is also performed manually by the users themselves. All other entry and exit maneuvers are performed automatically. The use of automated parking systems requires prior briefing of drivers, and intuitive user guidance ensuring maximum possible operational safety. These parking systems must offer on-call expert support, which can be provided by the car park attendant, the car park supervisor, or by reception facilities for instance. For this reason, automated and also mechanical parking systems are preferably frequented by fixed user groups. Their public use is rare in Germany. Use and advantage In Germany these facilities are built and used if the required and economically viable number of parking spaces cannot be provided, at the desired quality levels, by using purely structural means and conventional systems. In many dense urban locations, above-ground space is expected to be kept free for other primary urban and civic uses, resulting in the fact that a high number of car parks in general, and automated parking systems in particular, are built underground, at significantly higher costs than building them above ground. One of the main advantages of automated parking systems is the fact that they require less floor space and building site space. They are particularly advantageous when the available floor space in buildings on small lots is so limited that it is impossible to build a complete parking access lane with a user-friendly ramp. The more efficient use of floor space by automated parking systems is primarily due to the replacement of ramps by vertical conveyors, and a deeper, multiple-row layout. Moreover, clearance in the holding areas needs only be high enough to fit actual vehicle dimensions, resulting in additional space savings. Permissible vehicle dimensions To make full use of existing floor space, automated parking systems are designed to meet precisely defined vehicle dimension requirements, including certain reserve margins, and not built to accommodate vehicles of all and any dimensions, but only those relevant to a particular location, use, or host building. Table 1 shows the maximum vehicle dimensions (including protruding parts such as extended external Maximum car park-compatible dimensions Europe USA, Middle East Standard case With increased weight (excluding large pick-up trucks) Total laden weight 2,500 kg 3,000 kg 3,200 kg (ca. 7,000 lbs) Height 1.70 m/ 2.,00 m ≤ 75%/ ≥ 25% 1.70 m/ 2.10 m ≤ 75 %/ ≥ 25 % 1.70 m/ 2.10 m (ca. 67’’/ 83’’) ≤ 67 %/ ≥ 33 % Length 5.25 m 5.35 m 5.70 m (225’’) Width with external mirrors 2.20 m 2.30 m 2.30 m (90’’) Ground clearance, minimum manageable dimensions ≤ 80 mm ≤ 80 mm ≤ 80 mm (3’’) Table 1: Recommendations for maximum vehicle dimensions to be accommodated by automated car parks International Transportation (67) 2 | 2015 41 Car Parking SCIENCE & RESEARCH mirrors, roof antennas and trailer gear) for car park construction projects in Europe and other regions. These dimensions ensure that nearly all currently available limousine and estate car types can be parked in automated parking systems. To meet the demand for parking spaces for vehicles with larger than car park-compatible dimensions, it may be recommended to allocate some conventional parking spaces on the entry level, for example. It must also be taken into account that the largest permitted car park-compatible vehicle dimensions represent absolute limits that must not be exceeded, as this would otherwise pose the risk of collision between vehicles and system parts. Stacking principle An important differentiating feature of automated parking systems is the stacking principle. In cases where vehicles remain stationary in their respective parking spaces during the entire parking time and are being shifted only for stacking and retrieval, we speak of so called static systems. In dynamic systems, on the other hand, the vehicle conveyance system doubles as parking space provider, resulting in the fact that retrieval of one vehicle requires prior shifting of other vehicles. Table 2 shows a classification of automated parking systems according to the stacking principles and loadbearing systems used. Parking procedure The actual parking process starts with a simple action after drivers have alighted from their vehicles and left the transfer cabin: The respecting parking pallet is taken over by the system and placed into a shelved space. In sliding pallet systems, the pallet is brought into circulation, permitting a vehicle to park on a vacant pallet. As a rule, a parking process typically ends with the provision of an empty pallet in the transfer cabin, ready for the next user. Depending on local conditions, vertical conveyors and horizontal conveyors as well as turntables can additionally be employed. Manufacturers are basically free to choose the working mechanism of their conveyor technologies and other technical details, while adhering to the applicable basic technical norms and safety standards. In pallet-free systems, the parking process proceeds in a similar manner for drivers. Vehicles are driven onto a completely flat transfer area or into a transfer device, which requires precise positioning for loadlifting. The principal difference lies in the technology employed for conveyance and in the resulting system features. In cases where entry and exit of parking spaces take place in opposite direction to the driving direction, turntables are used to turn the vehicle around even before it is placed in the car park to ease its later exit. This allows vehicles to exit the transfer cabin facing forward. In parking towers with centrally located storage and retrieval systems, turntables are located within. Turntables are also required if the direction of the vehicle holding space is not parallel to the parking direction. When a vehicle is to be retrieved, swiping the corresponding identification element or holding it up to a card reader activates the vehicle retrieval process. Following the removal of the vehicle by the conveyor system, the vehicle is placed in the transfer cabin, ready to be driven out by the driver. If desired, users can alternatively also simply load or unload items from the vehicle and subsequently send it back to the holding area. Planning automated parking As experience shows, automated parking systems require specialist knowledge during all phases from planning to operation, to allow them to be efficiently used as mature technical solutions. It must be noted that there are basic differences in the qualitative, technical safety-related and operational requirements in various product markets and in terms of the available parking systems. These specific features are determined by the following factors, among others: • Strict application of the applicable EN norm in the areas where in force, resulting in high safety standards for users and the provision of automatic gates, locking devices, as well as devices protecting the users against falling, getting stuck and tripping, and other similar requirements, which contrasts with other markets that mostly tolerate larger residual risks; • Operation by briefed user circles, a car park attendant or by the public; • Comfort and safety in the transfer cabins; • The value of architectural integration; • The desired system dynamics and redundancies; • Low-noise operation based on modern construction methods and acoustic decoupling from the building structure; • Availability rates as per the relevant VDI norm (minimum requirement: 99 %) and reliability; • Service system based on qualified event recording, tele-service and remote access while meeting local safety regulations (generally with local staff support for additional risk identification capability, which cannot be provided adequately by tele-service alone); • Long-term guarantees to ensure sustainable and economically predictable operation over 20 years, for example. Configuration of automated parking-systems As for any other parking system, the configuration of an automated parking system should, right from the start, involve a specialist planner with experience in designing automated parking systems. This is the only way to compare the advantages and disadvantages of all potentially suitable parking systems, both conventional and automated, and to find the best solution, as not every automated parking system is suited to every location. For optimum results, manufacturer-independent planning is required, meaning that developing a coherent overall concept takes precedence over simply choosing a suitable conveyance type and going from there. The solution that is finally implemented must be configured and optimized for the specific conditions of the respective location. Apart from technical and traffic planning issues, economic evaluation is also required. As such, by referring to generic features, the scope of this section includes a few guiding points, without laying claim to exhaustively covering all relevant aspects. The installation of additional conveyance devices, empty spaces or transfer cabins that may be desired to enhance performance actually tend to cancel out the spacesaving benefits offered by automated parking systems. Parking system as per EAR 05 Storage principle Load-lifting system Parking shelves Static/ in multiple-fold storage systems partly dynamic Parking pallets/ pallet-free Pallet shifting system Dynamic Parking pallets Circulating system Table 2: Storage principles and load-lifting systems of automated parking systems International Transportation (67) 2 | 2015 42 SCIENCE & RESEARCH Car Parking Typical reference values System-related logistical time periods typical for a parking shelf are given as follows: For each transfer cabin, a 2to 2.5-minute rhythm can generally be assumed, depending on its access links and without claiming general applicability. Minimum vehicle retrieval periods stand at around 45 seconds. The maximum retrieval period in high-bay stacking systems of reputable manufacturers stands at around 3 to 3.5 minutes, while in pallet-shifting systems retrieval takes around 5 minutes. These time periods are quite acceptable compared to those in conventional car parks, where users have to walk to their vehicles and often lengthy maneuvering and driving processes are required. Inbound parking procedures are often shorter because there are fewer transfers. For the calculation of outbound and inbound parking performance, personal transfer cabin occupation times including possible waiting periods for the use of other conveyance devices and processes must additionally be considered. Examples Automated car parks with more than 500 parking spaces are rare. As a rule, in Germany, for large parking facilities it has proven more cost-effective to fall back on conventional solutions. Moreover, it is strongly recommended to exclusively use system types that are based on the proven basic structures of experienced manufacturers. The largest automated parking system in Europe was recently planned in Aarhus, Denmark, and provides 1,000 parking spaces using a ‘shuttle-lift’ system (see figure-1 and figure 2). More common are systems with up to 20 parking spaces on small building sites, as shown in figure 3 and figure-4. Automated parking systems fit into today’s modern world, but their complex technical layout and processes require specific planning expertise. Moreover, original investment and operating costs per parking space are relatively high. The advantages of automated parking systems regarding the use of available floor space and building site space can only be meaningfully assessed when all relevant criteria (available cubage and ground area, number of parking spaces, vehicle dimensions, location of the entry and exit drives or of the transfer cabins, traffic-related and system-related logistical requirements, etc.) are considered. ■ LITERATURE [1] Forschungsgesellschaft für Straßen- und Verkehrswesen e.V.: EAR 05 - Recommendations for facilities for stationary traffic, Cologne, 2005 [2] Verein Deutscher Ingenieure: VDI 4466. Automated parking systems - Basic principles, Düsseldorf, 2001 Ilja Irmscher, Dr.-Ing. habil. Managing Director, GIVT Gesellschaft für Innovative VerkehrsTechnologien mbH Planning services for parking, Berlin-(DE) irmscher@givt.de Figure 1: Automated parking system in Aarhus, public use, 1,000-parking spaces, shuttle-lift system and transfer cabin Photo: Lödige Industries Figure 2: Entrance to Aarhus automated parking Photo: Lödige Industries Figure 3: Automated parking system in Munich Karlstrasse, exterior view Photo: GIVT Figure 4: Automated parking system in Munich Karlstrasse, transfer cabin Photo: GIVT