開發(fā)商不斷為高級駕駛員輔助系統(tǒng)（ADAS）增添新功能，提升精密性，因此該系統(tǒng)變得越來越復(fù)雜。Elektrobit、英偉達(dá)(Nvidia)和英飛凌(Infineon Technologies)也為此攜手合作，致力于提供ADAS解決方案，作為自動(dòng)駕駛技術(shù)的研發(fā)平臺。該方案整合了英偉達(dá)的Drive PX自動(dòng)駕駛計(jì)算機(jī)，英飛凌的AURIX 32位TriCore，以及Elektrobit的符合AUTOSAR 4.x標(biāo)準(zhǔn)的 EB tresos軟件套裝。
英偉達(dá)的Drive PX可以分析并整合高清攝像頭和傳感器的輸入數(shù)據(jù)，英飛凌的Aurix實(shí)時(shí)處理器能夠提升內(nèi)置安全性；Elektrobit的tresos軟件有助于整合Linux系統(tǒng)和AUTOSAR應(yīng)用，并保證多CPU通信在高安全高完整性的環(huán)境中進(jìn)行。解決方案順應(yīng)了許多行業(yè)發(fā)展趨勢，包括功能性安全、計(jì)算能力提升、多用途通信、和冗余設(shè)計(jì)。
“我們的軟件運(yùn)行載體是一塊裝有2片英偉達(dá)Tegra芯片和1片英飛凌Aurix TriCore芯片的電路板，”EB自動(dòng)駕駛項(xiàng)目總監(jiān)Karsten Hoffmeister表示。“電路板配有CAN、LIN、以太網(wǎng)和FlexRay通信通道，而且還設(shè)計(jì)了冗余以太網(wǎng)連接路徑。如果某條線路出現(xiàn)故障，其他線路可以保證軟件正常運(yùn)行。”
這種一塊電路板集成多處理器的方法說明，單電子控制單元（ECU）是未來的發(fā)展趨勢，這種做法可以分析多渠道輸入信息，以便做出駕駛決策。減少ECU的數(shù)量，提升其性能的做法也可以簡化系統(tǒng)架構(gòu)，并降低成本。工程師們正在努力減少控制器，但同時(shí)也在增加后備系統(tǒng)，以保證安全系統(tǒng)不會(huì)因?yàn)槟骋粋€(gè)元件的故障而全面崩潰。
“從系統(tǒng)層面來說，只用單個(gè)ECU是不可能的，還需要冗余系統(tǒng)，”Hoffmeister表示。“目前，容易出現(xiàn)單點(diǎn)故障的還是電源供應(yīng)器。我們今后會(huì)采用雙電源供應(yīng)器。”
ADAS系統(tǒng)越來越精密復(fù)雜，這也促進(jìn)了AUTOSAR的使用。設(shè)計(jì)團(tuán)隊(duì)可以用軟件模塊處理低級別任務(wù)，這樣他們可以集中精力研發(fā)高級別操作。
“對于非基于信息娛樂系統(tǒng)的部件研發(fā)來說，例如剎車裝置、方向盤、和發(fā)動(dòng)機(jī)控制元件，AUTOSAR的確是標(biāo)準(zhǔn)架構(gòu)，”Hoffmeister表示，“有了AUTOSAR，就無需人力重復(fù)配置CAN堆棧了，而且界面也非常穩(wěn)定。但整車廠各有偏好，特別是在診斷和升級方面。”
Hoffmeister指出，標(biāo)準(zhǔn)應(yīng)用仍任重而道遠(yuǎn)。
“AUTOSAR很復(fù)雜。我們對它進(jìn)行了一些預(yù)先設(shè)置，運(yùn)行變的非常簡易。這樣用戶就不用花時(shí)間配置了，”他說。“AUTOSAR仍然是為專業(yè)人士設(shè)計(jì)的，使用者應(yīng)該認(rèn)真了解它的操作原理。”
越來越多的整車廠和一級供應(yīng)商開始使用AUTOSAR生產(chǎn)車輛，Linux的地位可能會(huì)有所變化。Elektrobit的軟件套裝也包括Linux，但現(xiàn)階段而言，它的功能很大程度上局限于設(shè)計(jì)和測試領(lǐng)域。
“Linux非常適合研發(fā)活動(dòng)，有很多現(xiàn)成的資源可以使用，”Hoffmeister表示。“在最初的研發(fā)階段，可以先在電腦上用Linux；進(jìn)入量產(chǎn)階段后，根據(jù)效果，可以僅在特定部件中使用。”
以太網(wǎng)的整合說明，整個(gè)產(chǎn)業(yè)正在越來越多地采用商業(yè)化技術(shù)。網(wǎng)絡(luò)的傳輸速率更快，靈活性更高。
“很多整車廠已開始使用以太網(wǎng)，因?yàn)閹捀螅?rdquo;Hoffmeister表示，“攝像頭可以傳送以太網(wǎng)幀，這更利于數(shù)據(jù)處理。此外，如果你提供了一項(xiàng)服務(wù)，之后想做出改變，也可以動(dòng)態(tài)分配服務(wù)和調(diào)整服務(wù)質(zhì)量。”
作者：Terry Costlow
來源：SAE《汽車工程雜志》
翻譯：SAE 上海辦公室
Elektrobit, Nvidia, and Infineon team up to tackle safety systems
Advanced driver assistance systems (ADASs) are becoming increasingly complex as developers add capabilities and enhance sophistication. That’s prompted Elektrobit,Nvidia, and Infineon Technologies to team up and offer an ADAS solution that can serve as a development platform for autonomous driving. The solution consists of the Nvidia Drive PX self-driving computer, Infineon’s AURIX 32-bit TriCore, and Elektrobit’s AUTOSAR 4.x-compliant EB tresos software suite.
Nvidia Drive PX makes it possible to analyze and combine multiple HD camera and sensor inputs, while the Aurix real-time processor has enhanced embedded safety and security features. Elektrobit’s tresos software facilitates the integration of Linux and AUTOSAR applications and enables cross-CPU-communication at high safety integrity levels. The companies are addressing many trends, including functional safety, increased computing power, versatile communications, and redundancy.
“Our software runs on a board with two Nvidia Tegra chips and an Infineon Aurix TriCore chip,” said Karsten Hoffmeister, Director of EB’s autonomous initiatives. “The board has CAN, LIN, Ethernet, and FlexRay communications channels, with redundant Ethernet connection paths so if something goes wrong the other channel will be available.”
Combining multiple processors on a board highlights the drive towards a single electronic control unit (ECU) that analyzes many inputs so it can make driving decisions. Using fewer, more powerful ECUs will also simplify architectures and reduce costs. While engineers attempt to trim the number of controllers, they’re also adding backups to ensure that safety systems don’t break down because a single element fails.
“At the system level, you’re not able to use one single ECU. You need redundancy,” Hoffmeister said. “Right now, the single point of failure is still the power supply. In the future, we’ll see two power supplies.”
The increasing complexity of ADAS is also prompting greater use of AUTOSAR. It lets design teams use software modules for common low-level tasks so they can focus on high-level operations.
“AUTOSAR is really the standard architecture for developing non-infotainment-based parts of the vehicle like brakes, steering, and engine control,” Hoffmeister said. “Instead of having people configure the CAN stack again and again, we’ve done it. With AUTOSAR, the interface will be stable, though all the OEMs have their own flavor, especially in diagnostics and updating.”
Hoffmeister noted that using the standard still requires a fair amount of effort.
“AUTOSAR is complex. We have predefined a lot so it runs easily. They don’t have to spend weeks,” he said. “AUTOSAR is still really for specialists; people using it should really take care to understand it.”
While more OEMs and Tier 1s are using AUTOSAR in production vehicles, Linux is another story. It’s included in Elektrobit’s software suite, but at present, its role will be largely limited to design and testing.
“Linux is very good for development, there are lots of libraries out there,” Hoffmeister said. “You can start out using Linux on a PC; then when you go to mass production you can reduce Linux to certain parts where it works.”
The inclusion of Ethernet also highlights the industry’s growing adoption of commercial technologies. The network permits faster transfer rates and more flexibility.
“Many OEMs are moving to Ethernet for bandwidth,” Hoffmeister said. “Cameras can send Ethernet frames, and it’s good for data. Also, if you offer a service and want to change it later, you have dynamic allocation of services and quality of service.”
Author: Terry Costlow
Source: SAE Automotive Engineering Magazine
Elektrobit，英偉達(dá)和英飛凌正在幫助開發(fā)商優(yōu)化ADAS設(shè)計(jì)。