Autonomous Micro Aerial Vehicles (MAVs), with a form factor of 10cm in diameter, are an emerging technology thanks to the broad applicability enabled by their onboard intelligence. However, these platforms are strongly limited in the onboard power envelope for processing, i.e., less than a few hundred mW, which confines the onboard processors to the class of simple microcontroller units (MCUs). These MCUs lack advanced security features opening the way to a wide range of cyber security vulnerabilities, from the communication between agents of the same fleet to the onboard execution of malicious code. This work presents an open source System on Chip (SoC) design that integrates a 64 bit Linux capable host processor accelerated by an 8 core 32 bit parallel programmable accelerator. The heterogeneous system architecture is coupled with a security enclave based on an open source OpenTitan root of trust. To demonstrate our design, we propose a use case where OpenTitan detects a security breach on the SoC aboard the MAV and drives its exclusive GPIOs to start a LED blinking routine. This procedure embodies an unconventional visual communication between two palm sized MAVs: the receiver MAV classifies the LED state of the sender (on or off) with an onboard convolutional neural network running on the parallel accelerator. Then, it reconstructs a high-level message in 1.3s, 2.3 times faster than current commercial solutions.
翻译:自主微型飞行器(Micro Aerial Vehicles,简称MAVs)因其内置智能而在广泛应用的领域崭露头角,其直径为10厘米。然而,这些平台的内置功率受到严格限制,即少于几百mW,这将微控制器单元(MCUs)的内置处理器限制为简单的类别。这些MCUs缺乏高级安全功能,为从同一机群中代理之间的通信到恶意代码的内部执行开辟了广阔的网络安全漏洞。本文提出了一个开源的SoC设计,该设计集成了一个64位的Linux主机处理器,由8核32位并行可编程加速器加速。异构系统架构与基于开源OpenTitan根的信任的安全信封相结合。为了证明我们的设计,我们提出了一种用例,其中OpenTitan检测到MAV机内SoC的安全漏洞,并驱动其独享GPIO,启动LED闪烁例程。这个过程体现了两台手掌大小的MAV之间的非传统视觉通信:接收器MAV使用并行加速器上运行的卷积神经网络对发送器的LED状态(开或关)进行分类。然后,它在1.3秒内重建高层次消息,比当前商业解决方案快2.3倍。