在創新自動駕駛汽車的研發世界中，信任、安全、保障，這些關鍵字就像是一個魔咒，時時縈繞在每一位工程師、研究人員和設計師的腦海中。為了讓自動駕駛汽車真正成為一種為大眾所接受的可靠技術，這些都是必須克服的挑戰。
不過，還有一個同樣不容忽視的關鍵字，那就是測試。為了贏得大眾對自動駕駛汽車的信任，汽車行業必須針對自動駕駛汽車的整體及各個組成部分進行大量測試，其深度與廣度均將遠超出以往任何時間。在此背景下，供應商和政府機構也專門建立了大量試驗場，為支持汽車原始設備廠商的自動駕駛汽車事業，以及推動 SAE 5 級自動駕駛汽車的大規模普及作出了重要貢獻。
整體來說，這些機構主要采用了“虛實結合”的測試方式，也就是“虛擬測試工具”結合“真實世界測試”。最近，在歐洲地區，位于瑞典 Borås 的 AsTazero 5G 試驗場已經正式揭幕啟用（其他類似的設施還包括位于英國的 Milbrook 試驗場和位于英格蘭的 HORIBA MIRA 試驗場）。AsTazero 5G 試驗場是瑞典研究所（RISE）與哥德堡查爾莫斯理工大學的成功合作成果，內部設置了多條高速公路測試道路，且已廣泛覆蓋 5G 網絡。
AstaZero 成立于 2014 年（不過，瑞典研究所自身的自動駕駛研發工作則可以追溯至2008 年），據稱為世界上首座致力于地面車輛自動駕駛和主動安全測試的設施，能夠“模擬世界任何城市中的幾乎任何交通狀況”。正如上文介紹，AstaZero 正是通過“虛實結合”實現這一點的，即借助 5G 連接和分布式云服務，將虛擬世界和現實世界的交通環境混合起來，且還可以加入“行人”等可變參數，進一步增加測試環境的復雜度。
揭幕儀式上，AstaZero 首席執行官 Peter Janevik 表示：“很顯然，汽車行業必須具備更好、更快、更復雜的測試設施，否則很難真正啟動公共道路上的真實自動駕駛產品測試。”Janevik 先生稱，AstaZero 園區（現已具備復制幾乎所有車輛行駛環境的能力，包括非公路車輛）可以提供世界上最先進的測試環境。借助于 5G 連接的超高傳輸速度和準確性，AstaZero 試驗場可以復制現實世界中的幾乎所有真實交通狀況，“這是以往任何試驗場都做不到的”。
虛實結合
AstaZero 園區將同時啟用“實體測試車輛”和“虛擬測試車輛”，在測試循環中運行現實世界中的應用程序，并創造了一種“有自動駕駛汽車參與”的交通環境。AstaZero 試驗場中還設置了自行車道、城市環境（考慮到目前全球城市化進程的腳步，這點尤為重要）、鄉村道路和多車道高速公路等交通環境，理論上可以考慮行人（比如人行道上的大量行人），甚至無人機對自動駕駛汽車行駛的影響。
AstaZero 試驗場還通過與 WARA-CAT、愛立信（Ericsson）和 PTS 等供應商的合作，實現了 5G 通信網絡的廣泛覆蓋，并具備了與電信運營商、終端用戶設備與第三方開發者合作的能力。在 Janevik 對 AstaZero 試驗場的規劃中，國際數據共享是非常重要的一環。目前，AstaZero 試驗場在歐洲、美國和遠東均有合作伙伴，并希望見到自動駕駛汽車測試系統的 ISO 標準化，以促進全球不同地區測試結果的相互比較，這對“促成自動化車輛的大量測試”至關重要。
行業顛覆者
英國 Millbrook 試驗場首席自動駕駛汽車工程師 Peter Stoker 認為，建立國際合作機制非常重要，但我們同時也必須意識到行業顛覆者的存在。“沒錯，現在國際上正在討論建立合作機制，但我們也必須意識到一些行業顛覆者的存在，”Stoker 解釋道，“這些顛覆者可能不是汽車制造商，反而很多都是一些試圖突破技術邊界的初創企業。然而，他們的技術到底是否具備與我們合作的基礎？這點我們真的說不準。”
Stoker 認為，Millbrook 試驗場具備一系列世界一流的真實世界駕駛設施，在自動駕駛汽車測試中最重要的任務莫過于打造安全系統。“我們可以確保所有開發工作都是在一個安全、可靠的環境下進行的，而且都可以經過適當的測試。”他表示，“事實上，一些汽車消費者可能覺得現有的先進駕駛輔助系統（ADAS）已經有點太過了，而另一些人卻覺的還不夠。但無論如何，汽車行業都必須確保自動駕駛汽車可以贏得大眾的絕對信任。
“如今，有關自動駕駛的炒作從來沒有停止，但我們必須明確告訴大家，自動駕駛汽車并不會在未來幾年中大量出現在人們的生活中。”Stoker 強調，“而且，即使自動駕駛汽車最終真正到來，也一定是先在有限區域中進行有選擇性的逐步推廣，比如“貨物運輸”和“最后一英里通勤”等行駛路線較為固定的行駛場景，這都將幫助社會逐漸接受自動駕駛技術。”
原子能合作機構
目前，Millbrook 試驗場還在進一步擴大其自動駕駛汽車測試能力，除了現有的大約 70 公里的測試軌道，還計劃增加更多測試臺。此外，Millbrook 試驗場還有一個看起來很不相關的合作伙伴—英國原子能管理局（UKAEA）。英國原子能管理局有一個下屬機構，名為 RACE（Remote Applications in Challenging Environments），正在利用自動引導車（AGV），比如輪式機器人等，處理各種任務方面具有豐富的經驗。
英國原子能管理局的 Culham 科學中心占地約 200 英畝，其中設置了大約 10 公里的測試道路。不過，Millbrook 和 Culham 的最大區別在于：Millbrook 實質為一個幾乎沒有行人的封閉環境，而 Culham 則更像是一個非常安全的大學校園，其中有很多行人、丁字路口、二層小樓及其他各種常見道路場景。Stoker 表示：“我們與電信設備供應商有大量合作，安裝了許多桅桿，實現了通信網絡的廣泛覆蓋。”目前，這些站點之間可進行無縫信息傳遞，實現互聯。
不過，Millbrook 試驗場的全部 5G 研發均由 AutoAir 財團支持，主要扮演“5G 試驗臺”的角色。AutoAir 是一家由英國政府資助的財團，其成員包括邁凱輪應用技術公司（McLaren Applied Technologies）。目前，在 LTE 通信供應商 Airspan Networks 的幫助下，Millbrook 試驗場正在進行適用自動駕駛汽車的 5G NR 技術開發。
目前，Millbrook 試驗場的 5G NR 項目主要是對這種新型通信技術進行適配，使其適用于自動駕駛汽車的驗證與研發。Stoker 補充說，“試驗臺是我們的，但開發主要是財團方面進行的。”現階段，試驗臺上有 23 個通過光纖主干連接的基本單元，可在測試道路附近提供低延遲的廣域 5G 通信，提供實時 Gbps 連接服務，而這被視為 SAE 3 級到 5 級自動駕駛汽車驗證工作的必要條件。
除了 5G NR 項目，Millbrook 試驗場的另一個新項目是模擬套件研發。該套件可以提供試驗場內所有硬表面車道的數字模型（來自軟件專家 RFPro），供OEM和供應商使用，精度非常之高。“當項目研發完成后，廠商可以將自己的車輛送到 Millbrook 試驗場，然后開始各種虛擬環境測試。”Stoker 表示：“技術的演示非常重要，而且更重要的是在真實環境中完成這一切。目前，保險公司已經對我們在 Millbrook 的工作產生了濃厚興趣。”
Stoker 表示，自動駕駛汽車的實車測試需求還將繼續存在，但 80% 到 90% 的研發工作是可以通過虛擬手段實現的。
極限控制測試
HORIBA MIRA 試驗場位于英格蘭 Midlands 地區。該試驗場的自動駕駛汽車測試負責人 Chris Reeves 也認同“虛實結合”的測試方法，即在設計和工程階段利用模擬和建模獲得更多信息，并最終在真實世界中進行測試和驗證。“HORIBA MIRA 擁有世界首套自動駕駛汽車測試城市駕駛環境及相關基礎設施，”Reeves 表示，“我們還在搭建一處新的設施，從而進行更高層次的系統控制極限測試。”
Reeves 表示，自動駕駛汽車測試的一個重要部分是理解“邊緣情景”，但我們很難在真實世界中大量復現極端環境，這并不現實。此時，模擬和建模的方法就可以發揮重要作用了。Reeves 表示，“我可以舉一個很簡單的例子，當我們在測試汽車的極端性能時，車輛可能已經接近，甚至已經處于失控狀態。這時，在真實世界中進行這些測試是非常危險的。”Reeves 表示，自動駕駛汽車可以帶來的社會和環境效益是無需多言，“只要我們能夠建立足夠的信任，就可以讓大眾享受更加包容的移動出行解決方案。”
實話實說
Reeves 表示，根據我們與OEM合作的經驗，汽車行業的自動駕駛汽車研發主要有兩種措施：第一種為“一步到位式”，也就是直奔非常高水平的自動化級別，也就是直接達到 SAE 4 級和 SAE 5 級自動駕駛；第二種則為“循序漸進式”，即利用汽車行業中已經存在或即將出現的技術，逐步對車輛的自動化功能進行優化，進而提高車輛的便利性和安全性。與 Millbrook 的 Stoker 的一樣，Reeves 也視“貨物運輸”和“最后一英里”為邁向高級別自動駕駛汽車的明智之舉。他表示，“這種措施更加安全可靠，并可以在一定程度上規避公共道路測試所需的各種要求。”
HORIBA 是一家總部位于日本京都的測量和測試系統生產商，在 2015 年收購了英國測試機構 MIRA。那時候， MIRA 已經在自動駕駛汽車測試方面積累了 10 年經驗，是最早一批預見到汽車行業重大變革并主動采取行動的公司之一。如今，HORIBA MIRA 正在擴建一個長度為 1079 米，最大寬度為 300 米的新測試設施，從而打造一個更加靈活的駕駛環境。目前，HORIBA MIRA 已具備“多條”測試道路，包括越野和城市駕駛環境。
自動駕駛汽車何時才能在歐洲和美國大量出現？Reeves 表示，實話實說，這個問題沒有一個簡單的答案。“SAE 4 級和 SAE 5 級自動駕駛功能可能還要十幾年才會真正出現在公共道路中，而且在此后很長一段時間中，我們仍將生活在一個傳統汽車和自動駕駛汽車共存的道路環境中。在可預見的將來，人們仍將承擔一定駕駛任務。”
Trust, safety, security. Those words form a mantra that needs to be in the forefront of the mind of every engineer, researcher and designer responsible for creating the brave new world of autonomous vehicles (AV). They are the standout “musts” of a lexicon that describes the dangers and challenges in making AVs a credible, and publicly accepted technology.
But there is one more “must”: testing. To engender public confidence, it has to be taken to a breadth and depth that the auto industry has never before experienced, involving every component and aspect of integrated autonomy. Playing a major part in this by supporting OEMs, suppliers and government legislators are dedicated testing facilities that will enable SAE Level 5 autonomy to become a high-volume reality.
These facilities are developing virtual tools in conjunction with the physical testing environment to speed the acceptance of every aspect of AVs. In Europe, a member of this select group is the recently unveiled AstaZero 5G facility in Borås, Sweden (others include Millbrook and HORIBA MIRA). It includes a high-speed multi-highway track and 5G capability and is a partnership between the Swedish state-owned Research Institutes of Sweden (RISE), and Chalmers University of Technology, Gothenburg.
AstaZero was established in 2014 (although early self-driving work was carried out by RISE in 2008). It describes itself as the first test facility in the world dedicated to automated driving and active safety of ground vehicles that is “able to simulate almost any traffic situation in any city on Earth.” It does this by blending virtual and real-world traffic complexity and pedestrians on its track, using 5G connectivity and distributed cloud services.
Peter Janevik, CEO of AstaZero said at the unveiling: “The automotive industry clearly needs better, faster and much more complex test facilities before new self-driving products can be safely tested on public roads.” He described the facility (which has the capability of replicating scenarios for almost any vehicle, including off-highway) as having the world’s most advanced test environment, the use of 5G providing the speed and accuracy that can replicate real-world traffic complexity “unlike anything that’s been seen before”.
Mixing and matching
It does so by mixing test vehicles with virtual vehicles; runs real-world applications in the test loop; and creates theoretical traffic environments in which autonomous vehicles share roads taking into consideration the effect of populated sidewalks (pavements) and even the presence of drones. Test areas at Borås include bicycle, city (significant in view of global population drift towards urbanization), rural road and the high-speed multi-lane.
Use of the 5G network (developed in partnership with WARA-CAT, Ericsson and PTS) includes the ability to work with telecom operators, plus end-user equipment and third-party developers. International data sharing is very much on Janevik’s agenda for AstaZero, which has collaborative partners in Europe, the US and the Far East, and wants to see an ISO standardized testing system to facilitate worldwide comparable results, vital to make the “massive amounts of testing for automated vehicles feasible."
The disruptors
In the UK, Peter Stoker, chief AV engineer at Millbrook Proving Ground, is well aware of this but also of the need to be cognizant of business disruptors. “Yes, there is now international discussion about co-operative systems, but we have to consider disruptors,” he explained. “These are not vehicle makers. Many are start-ups trying to push technological boundaries. How co-operative their technologies will be we really do not know.”
With its range of real-world driving facilities, Stoker sees Millbrook’s overarching AV task as achieving safe systems. “Ensuring that everything is developed in a safe and reliable way – and properly tested,” he said. “Some members of the car-buying public may already feel that ADAS is doing more than it should; others are expecting more of their vehicles than they can deliver. The auto industry needs to ensure that absolute trust is engendered.
“There is a lot of hype around. We need to put out a clear message that full [automated driving] will not come for cars in large numbers any time in the next few years,” he stressed, “and when it does there will be a selective roll-out in defined areas. Firstly, freight and ‘last mile’ use such as vehicle delivery on the same route every day. It will help society become used to self-driving vehicles.”
Nuclear partnership
Millbrook is expanding its AV test capability (it has 70km of test tracks) with more testbeds and is working with what may seem an unlikely partner, the UK Atomic Energy Authority (UKAEA). UKAEA has a division called RACE (Remote Applications in Challenging Environments) which has experience in automatically guided vehicles (AGV) – wheeled robots – tackling a variety of tasks.
UKAEA also has some 200 acres of land and 10km of roads at its Culham Science Center. The difference between Millbrook and Culham is that the former is a confidential environment with few pedestrians, while the latter is like a very secure university campus with many pedestrians. It has T-junctions, 2-storey buildings and common road scenes. “We have introduced extensive communications, linked with a telecoms equipment supplier to establish a connected environment and installed lots of masts,” Stoker said. The sites interlink via seamless information transfer.
All 5G development at Millbrook, though, comes under the aegis of a UK government-sponsored consortium to provide the transport element of the “5G Testbed”. The consortium, called AutoAir, includes McLaren Applied Technologies. Led by LTE vendor Airspan Networks, it is developing 5G New Radio (NR) for AVs.
The project will aim to make 5G NR technologies available for the validation and development of AVs. “We host the test bed but the consortium does the development,” added Stoker. There are 23 base units linked via a fiber backbone, providing a low latency, wide area 5G structure around the tracks, delivering the real-time Gbps connectivity regarded as crucial for SAE Level 3-5 validations.
Also new and a direct Millbrook project is a simulation suite that holds digital models (created by software specialist rFpro) of all the hard surface tracks at the facility to very high degrees of accuracy that can be used by OEMs and suppliers. “When project work is completed, a vehicle can be brought to Millbrook to correlate the virtual program and establish subsets,” Stoker said. “The key thing is demonstration of the technology and doing so in real environments. We are seeing insurance companies now becoming increasingly interested in our work at Millbrook.”
Stoker says he believes there will continue to be a need for physical testing of AVs to achieve verification although 80% to 90% of the development of a AV could be achieved virtually.
Limit of controllability
At HORIBA MIRA in the English Midlands, head of AV testing Chris Reeves agreed with the physical test-vehicle element, with simulation and modelling informing design and engineering stages and ultimately test and validation. “HORIBA MIRA developed the first urban driving environment for the testing of AV and associated infrastructure technologies,” Reeves said. “We are also creating a new facility that enables us to take systems to the limit of controllability.”
Reeves said that an important part of testing AV is to understand the “edge cases” – where simulation and modeling will play a major role because many of these tests will be impractical to reproduce within physical test environments. “For example,” he explained, “when a vehicle is being tested up to and beyond the limits of its controllability where it will be unsafe to do so in a physical environment.” Reeves says he believes the societal and environmental benefits of AVs are well understood: “Assuming we can create the level of trust required, we can help deliver an inclusive mobility solution.”
On the level
Working with OEMs, Reeves is experiencing two approaches to AV development by the auto industry. Firstly, the revolutionary – how to reach very high levels of automation (SAE Levels 4 and 5); secondly evolutionary, incremental progress to achieve more convenience and safety features using current and soon to emerge automated technology. Like Millbrook’s Stoker, he sees freight vehicles and particularly last mile applications as sensible steps on the incremental ladder to the high SAE Levels. “Not using it on a fully public road would enable control of the safety case and its requirements,” he said.
The Kyoto-headquartered measurement and testing systems producer HORIBA bought MIRA in 2015, a decade after the UK facility first became involved in autonomous vehicle testing, an early anticipator of a change that will totally reshape the global auto industry. Now it is expanding to incorporate a new facility 1070m in length and 300m maximum width to create flexible driving environments. HORIBA MIRA already has “multiple” test circuits embracing off-road and city driving areas.
When will we realistically see the mass appearance of AVs in Europe and the U.S.? There is no simple answer, Reeves said. “SAE Levels 4-5 on public roads are over a decade away. We will have mixed fleets on our roads for a very long time. For the foreseeable future people will enjoy taking part in the driving task.”
Author: Stuart Birch
Source: SAE Autonomous Vehicle Engineering
無人機空拍：AstaZero測試場地包括“超級高速公路”。
AstaZero虛擬世界的視圖，包括無人機。
Millbrook的5G網絡塔定位并由“光纖主干”連接。
由英國的HORIBA MIRA創建的虛擬街道。
由英國的HORIBA MIRA創建的虛擬街道。
