成功實現(xiàn)高度自動駕駛，所需的不僅是一系列先進(jìn)技術(shù)，還需要一位隨時準(zhǔn)備待命的駕駛員。
“我們在下一代高度自動駕駛車輛上使用紅外線駕駛員分析攝像頭，為研發(fā)‘駕駛員模型’收集數(shù)據(jù)。該模型不僅能告訴我們駕駛員的注意力集中程度，還能預(yù)測其重新掌握駕駛的反應(yīng)時間，”大陸汽車北美高級工程主管Ibro Muharemovic表示。
大陸汽車的第二代自動駕駛概念于上個月底對外公布。為此，大陸在其位于密歇根州Brimley的試驗場舉辦了一場媒體技術(shù)前瞻會。首先，Muharemovic與《汽車工程》雜志共同開啟了一個分為兩階段的駕駛演示。首先，他將車速提升至高速公路駕駛速度，接著他啟動了全車速自適應(yīng)巡航控制，并激活了高度自動駕駛模式。這輛經(jīng)過特殊配置的2014MY克萊斯勒300對駕駛員的操作做出回應(yīng)，自動將車速調(diào)至60 mph (97 km/h)，并在下一個傾斜轉(zhuǎn)彎口將車速降至46 mph (74 km/h) ，順利通過，接著又在直行道上恢復(fù)到高速公路的車速。
自2014年8月起，美國的測試工程師們輪流坐上下一代示范車的駕駛座，讓兩臺車內(nèi)攝像頭識別并跟蹤駕駛過程中的面部活動，收集到的數(shù)據(jù)將用于計算機駕駛員模型的研發(fā)。
“現(xiàn)階段我們只有一個非常初級的駕駛員模型，當(dāng)駕駛員向前看時，系統(tǒng)認(rèn)定駕駛員注意力是集中的，向側(cè)面看時為不集中。但是計算反應(yīng)時間是一項非常復(fù)雜的工程，因此我們需要海量的原始數(shù)據(jù)，” Muharemovic表示。
位于擋風(fēng)玻璃底部的一條橫跨儀表板的發(fā)光條可告知駕駛員當(dāng)前的駕駛模式。該技術(shù)在大陸汽車的“駕駛員注意力識別汽車”上首次使用。（詳見http://articles.sae.org/11842）
綠色表明當(dāng)前使用的是駕駛員輔助與全速自適應(yīng)巡航控制模式。藍(lán)色則表明汽車處于高度自動駕駛模式。橙色為待機模式，意味著駕駛員正在掌控駕駛。“非常直觀的視覺提示至關(guān)重要，” Muharemovic表示。
為了實現(xiàn)更接近人類駕駛員的自動駕駛風(fēng)格，大陸汽車在第二代示范車上安裝了高精度數(shù)字地圖信息。
“高精度地圖可以精確地反應(yīng)道路環(huán)境。它能提供準(zhǔn)確的信息，如車道數(shù)量，以及這些車道的彎道以及道路出口的確切位置等，” Muharemovic表示，“高精度地圖的信息可幫助我們在道路環(huán)境中確定車輛的位置。”
大陸汽車的示范車配備了一系列傳感技術(shù)。
下一代遠(yuǎn)程雷達(dá)可覆蓋前方250米（820英尺）的距離，開角為120度。其視野為近距雷達(dá)的兩倍，且覆蓋距離比用于第一代示范車的第三代雷達(dá)還多出50米（165英尺）。 側(cè)邊安裝了4個近距雷達(dá)，觀測距離90米（295英尺），開角120度。此外，第二代示范車還增加了一個360度環(huán)境照相機系統(tǒng)。
下一代無人駕駛概念使用了一臺安裝在擋風(fēng)玻璃上的前視立體照相機，用于偵測道路、識別行人、交通標(biāo)志、迎面的車燈光束和其他物體。
充足的冗余
“立體照相機使用兩套道路識別算法，分別由不同團(tuán)隊設(shè)計。只有這樣做我們才能比較兩套算法，并在傳感器內(nèi)添加冗余。” Muharemovic表示。
制動和轉(zhuǎn)向系統(tǒng)也有備份，這是為了應(yīng)對主系統(tǒng)發(fā)生問題時所設(shè)計的策略。除了驅(qū)動系統(tǒng)外，電力供應(yīng)系統(tǒng)也設(shè)計了冗余。“比如說，前雷達(dá)用的是一套電力系統(tǒng)，立體照相機用的是另一套電力設(shè)備和通訊線路，” Muharemovic說。
大陸汽車在密歇根的奧本山上配備了3輛高度自動駕駛示范車。第一代示范車選用了大眾的帕薩特。而目前的示范車則是兩輛克萊斯勒300，其中一輛用作傳感器融合/傳感架構(gòu)的研發(fā)平臺，另一輛則用于研發(fā)制動與轉(zhuǎn)向的冗余系統(tǒng)。
“我們的研發(fā)成果是全球共享的，所以當(dāng)我們的德國或日本同事在某個傳感器、系統(tǒng)或功能上取得了研究進(jìn)展，我們都會把它帶到這里來，而在這里獲得的成就，也會分享給其他地區(qū)的團(tuán)隊。” Muharemovic表示。“我們的合作伙伴也在進(jìn)行技術(shù)研發(fā)，他們研發(fā)成功后，我們也能夠獲益。”
Continental shows next-generation highly automated car
A highly autonomous driving vehicle needs a suite of advanced technologies and a ready-to-take-control driver.
“We’re using infrared driver analyzer cameras on our next-generation highly automated driving vehicle to collect data for the development of a ‘driver model.’ The driver model would tell us if the driver is attentive. And it would predict the driver’s reaction time to resume control of the vehicle,” said Ibro Muharemovic, head of Continental’s advanced engineering in North America.
Continental’s second-generation concept was featured during a media technology preview at the supplier’s Brimley, Michigan proving grounds late last month. Muharemovic began a two-lap driving demonstration with Automotive Engineeringby accelerating the vehicle to a highway speed. He then engaged the full-speed-range adaptive cruise control and activated the highly automated driving mode. The specially equipped 2014MY Chrysler 300 responded by autonomously driving at 60 mph (97 km/h), slowing to 46 mph (74 km/h) to navigate smoothly through a banked turn, then resuming highway speed through a straightaway.
Since August 2014, test engineers in the U.S. have been taking turns in the driver’s seat of the next-generation demonstrator as two in-vehicle cameras recognize and track facial movements during drive time. The accumulated data will aid in the development of a robust computer driver model.
“At this point, I only have a very early version of the driver model that indicates attentiveness when the driver is looking forward and inattentiveness when the driver is looking to the side. As for reaction time, that is a big, big undertaking. This is why we need lots and lots of raw data,” said Muharemovic.
A light bar running the length of the dashboard at the windshield’s base provides the driver a visual reminder of the current driving mode. The technology debuted on Continental’s Driver Focus Vehicle (see http://articles.sae.org/11842).
Driver assistance and full-speed adaptive cruise control engagement is indicated by a green light bar. When the light bar is blue, the vehicle is in the highly automated mode. An orange color indicates a stand-by mode, which means the driver is actively steering. “It’s important to have a straightforward, always visible way of knowing what driving mode the car is in,” Muharemovic said.
To facilitate a more human-like autonomous driving style, high-definition digital map information is being employed on the second-generation demonstrator.
“The HD map is a highly accurate representation of the road environment. It provides us with precise information, such as how many lanes there are, the exact curvatures of those lanes, and the exact location of roadway exits,” said Muharemovic, “HD map information helps us localize the vehicle on the road environment.”
Continental’s demonstrator is fitted with an array of sensing technologies.
Next-generation long-range radar looks forward 250 m (820 ft) with a 120-degree opening. That is double the field of view in the near range and an additional 50 m (165 ft) in the complete range compared to the third-generation technology used on the first-generation demonstrator. Four short-range radars look to the sides at 90 m (295 ft) with a 120-degree opening. The second-generation vehicle demonstrator also has a 360-degree surround view camera system, a feature the first-generation vehicle concept did not have.
The next-generation concept uses a windshield-mounted, forward-facing stereo camera for lane detection and to recognize pedestrians, traffic signs, oncoming high-beam headlights, and other objects.
Redundancies abound.
“The stereo camera has two lane recognition algorithms that were developed by two different teams. It was done that way so we can compare the outputs of each and get added redundancy in one sensor,” said Muharemovic.
There is redundant braking and steering in case something happens with the primary units. In addition to the actuation redundancies, there is redundancy with the power supply. “As an example, the front radar is on one power supply and the stereo camera is on another power supply and communication line,” said Muharemovic.
Continental has three highly autonomous demonstration vehicles in Auburn Hills, MI. First-generation technology was showcased on a Volkswagen Passat. Two Chrysler 300s are now part of the demonstration fleet, with one car being used as a development platform for sensor fusion/sensing architecture and the other car serving as a development platform for redundant braking and steering.
“We share development globally, so whenever my colleagues in Germany or Japan make an update to a sensor or a system or a function, we are able to bring it to this region and vice-versa,” said Muharemovic. “Our partner companies are also developing technologies and as those technologies become available, we’ll make the updates.”
大陸汽車正在位于密歇根州Brimley的540英畝測試場（如圖所示）及其他地方測試下一代高度自動駕駛示范車。（照片由Spencer Peeples拍攝）
這是大陸汽車的技術(shù)發(fā)展線路圖——從部分自動駕駛到高度自動駕駛，最后是完全自動駕駛。