开发商不断为高级驾驶员辅助系统（ADAS）增添新功能，提升精密性，因此该系统变得越来越复杂。Elektrobit、英伟达(Nvidia)和英飞凌(Infineon Technologies)也为此携手合作，致力于提供ADAS解决方案，作为自动驾驶技术的研发平台。该方案整合了英伟达的Drive PX自动驾驶计算机，英飞凌的AURIX 32位TriCore，以及Elektrobit的符合AUTOSAR 4.x标准的 EB tresos软件套装。

英伟达的Drive PX可以分析并整合高清摄像头和传感器的输入数据，英飞凌的Aurix实时处理器能够提升内置安全性；Elektrobit的tresos软件有助于整合Linux系统和AUTOSAR应用，并保证多CPU通信在高安全高完整性的环境中进行。解决方案顺应了许多行业发展趋势，包括功能性安全、计算能力提升、多用途通信、和冗余设计。

“我们的软件运行载体是一块装有2片英伟达Tegra芯片和1片英飞凌Aurix TriCore芯片的电路板，”EB自动驾驶项目总监Karsten Hoffmeister表示。“电路板配有CAN、LIN、以太网和FlexRay通信通道，而且还设计了冗余以太网连接路径。如果某条线路出现故障，其他线路可以保证软件正常运行。”

这种一块电路板集成多处理器的方法说明，单电子控制单元（ECU）是未来的发展趋势，这种做法可以分析多渠道输入信息，以便做出驾驶决策。减少ECU的数量，提升其性能的做法也可以简化系统架构，并降低成本。工程师们正在努力减少控制器，但同时也在增加后备系统，以保证安全系统不会因为某一个元件的故障而全面崩溃。

“从系统层面来说，只用单个ECU是不可能的，还需要冗余系统，”Hoffmeister表示。“目前，容易出现单点故障的还是电源供应器。我们今后会采用双电源供应器。”

ADAS系统越来越精密复杂，这也促进了AUTOSAR的使用。设计团队可以用软件模块处理低级别任务，这样他们可以集中精力研发高级别操作。

“对于非基于信息娱乐系统的部件研发来说，例如刹车装置、方向盘、和发动机控制元件，AUTOSAR的确是标准架构，”Hoffmeister表示，“有了AUTOSAR，就无需人力重复配置CAN堆栈了，而且界面也非常稳定。但整车厂各有偏好，特别是在诊断和升级方面。”

Hoffmeister指出，标准应用仍任重而道远。

“AUTOSAR很复杂。我们对它进行了一些预先设置，运行变的非常简易。这样用户就不用花时间配置了，”他说。“AUTOSAR仍然是为专业人士设计的，使用者应该认真了解它的操作原理。”

越来越多的整车厂和一级供应商开始使用AUTOSAR生产车辆，Linux的地位可能会有所变化。Elektrobit的软件套装也包括Linux，但现阶段而言，它的功能很大程度上局限于设计和测试领域。

“Linux非常适合研发活动，有很多现成的资源可以使用，”Hoffmeister表示。“在最初的研发阶段，可以先在电脑上用Linux；进入量产阶段后，根据效果，可以仅在特定部件中使用。”

以太网的整合说明，整个产业正在越来越多地采用商业化技术。网络的传输速率更快，灵活性更高。

“很多整车厂已开始使用以太网，因为带宽更大，”Hoffmeister表示，“摄像头可以传送以太网帧，这更利于数据处理。此外，如果你提供了一项服务，之后想做出改变，也可以动态分配服务和调整服务质量。”

作者：Terry Costlow

来源：SAE《汽车工程杂志》

翻译：SAE 上海办公室

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