ZigBee無線感測網路技術應用實例之探討：停車場車位自動化管理系統

Study on A Practical Application Using ZigBee Wireless Sensor Network- Automatic Parking Lot Management System

楊鑫忠(Hsin-Chung Yang)

指導教授 ： 黃國鼎

國立虎尾科技大學/電機資訊學院/電機工程研究所/碩士(2012年)

https://doi.org/10.6827/NFU.2012.00098

摘要

目前台灣的停車場車位管理方式主要是在停車場進出口處利用電子設備顯示車位並利用閘門管制合法進出之車輛。此方式建置非常簡單且成本低，但未提供更多資訊，對使用者尋找車位很不友善。除了可能會錯誤選擇停放於較遠之車位，或無法找到實際空閒車位外，甚至不同車輛同時找尋到相同之空閒車位。當停車場變大且利用率愈高時，使用者遇到前述問題將更嚴重。此外，以營收目的停車場一般會配合以計時或計次的方式進行收費，更會因車位資訊不足問題，造成使用者需多花時間停車而增加費用情形。尤其，在大型停車場並使用計時收費時，由於到停車場出口的時間變久，可能會造成超過計時單位而要多收費用，因而讓使用者延緩盡速離場意願。若增加計時緩衝時間，會降低業者經營之收益。反之，若是使用計次收費，除了容易降低短時間停放者停放之意願，也會造成停放者不願盡速離場之現象。無論為計時或計次的方式進行收費，其實要改善上述問題，只要能夠即時的知道停車場內的每一個車位狀況，作到停放多久便收費多少之正確性就可以解決了。因此本文將選擇利用ZigBee無線技術建構一具有大容量之混合拓樸架構作為本系統之監控網路使用。過去相關研究中，主要僅是利用ZigBee無線技術建立單一星狀拓樸(Star topology)或樹狀拓樸(Tree topology) 之網路直接應用於監控車位系統。而且，這些研究主要都是根據監控車位數量之多寡，來考慮提出不同之網路拓樸。再依據此網路拓樸，設計出所有節點均具有相同資料回傳等待時間之路由策略。因此，這些研究提出之網路拓樸與路由策略並未考慮監控計次與計時車位時不同之時效性，亦未考慮配合計次與計時車位收費所需之正確性。因此本研究將停車場規劃具有計次區與計時區外，再規劃一個具有最高車位專用權之VIP區。每個分區將依據其不同之監控時效需求，使用不同網路拓樸設計出一具有大容量之混合拓樸架構之網路。當完成上述拓樸架構之網路後，針對不同分區監控時效性需求，本文將提出一權重式路由策略，可同時有效監控不同分區車位之資訊。最後，本研究將使用韓國廠商開發之硬體設備ZigBex進行實作模擬。實驗中，將星狀、樹狀拓樸實際模擬在VIP區、計次區以及計時區之車位管理系統中。實驗結果顯示確實可以達到在所設計的時間內，即時接收到不同區之資料，達到有效率的車位監控管理。

關鍵字

ZigBee ； 星狀拓樸 ； 樹狀拓樸 ； 路由策略

並列摘要

The management system of parking lots in Taiwan is mainly to install gates to control the authorized vehicles and usually also to provide electric displays for the drivers to monitor available space. This solution is very simple and low cost for owners, but provides insufficient information to guide drivers to a proper parking space. As a result, the drivers probably park their vehicles with a long time and/or find an unsuitable space. Even they simultaneously park to the same space. The above conditions should more often happen in the large size of parking lots. In addition, the extra parking time results in the drivers might be charged much more in commercial parking lots, whether counting-based or time-based charge. Especially, in the case of large-size parks with time-based charge, vehicles spend more time to leave the parking lot. If the time over a unit of charge-hour, the drivers will be charged one more unit of fee as they check out to exit. The drivers could consider delay to leave the parking lot when this situation probably happens. In contrast, if owners provide a tolerance of charged-hour for drivers to exit, the owners will lose their benefits. On the other hand, in the case of parks with counting-based charge, the users with parking short time have a low trend to enter due to the higher fee of counting-based charge. The vehicles in parking spaces perhaps slow up to exit since drivers pay the same charge before leaving. However, the management system always exist an unfair treatment for drivers or owners. If each parking space’s situation can be monitored on real time, the unfair problem is possible to solve according to the actual parking time of each vehicle. Therefore, an automatic management system of large-size parking lot with hybrid-topology ZigBee network is presented to realize the solution. In previous studies, ZigBee networks applied to parking systems where the topology is considered with star or tree according to park size only. Based on the considered topology, the follow up routing scheme is designed to collect parking spaces’ situations with the same rule and same period. When the design is applied in a parking lot with both spaces of counting-based and time-based charge, the time-based vehicles cannot be collected their actual parking time to charge correctly due to the higher monitor sensitivity than counting-based ones. In this paper, the parking lot is considered to settle not only counting-based zone and time-based zone but also a special zone for VIP members with various monitor sensitivities. In order to real-time monitor each parking space’s situation within the different zones, each topology of the three zones is designed to match their monitor sensitivity, respectively. Then, the system combines the three topologies to form a large-scale hybrid topology network. According to the monitor sensitivity of each zone with corresponding topology, a Weighted-Polling Routing Method (WPRM) is proposed to monitor the space’s situations of the different zones simultaneously. Finally, a practical experiment is performed by the ZigBee equipment, named HBE-ZigBex. In the experiment, the star and tree topologies were applied to VIP, counting-based and time-based zones with different link length designs. The experimental results show the system can real-time receive the information of all parking spaces’ situations within the different zones and then manage well the parking lot.

並列關鍵字

ZigBee ； Star topology ； Tree topology ； Routing scheme

參考文獻

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