We introduce Phalanx, a failure-resilient truck pla- tooning system, where trucks in a platoon protect each other from sensor failures despite the lack of redundant sensors. For that, we first emulate the failed sensors by collectively utilizing other sensors across the platoon. If the failed sensor cannot be emulated, the control system is instantaneously reconfigured to a cooperative protection mode using only the live sensors. We take a scenario-based approach considering six scenarios with single and dual failures of the essential sensors (i.e., lidar, encoder, and camera) for platooning control. For each scenario, we present a protection method that enables the safe maneuvering of platoons. For the evaluation, Phalanx is implemented using our scale truck testbed instrumented with fault injection modules, demonstrating safe platooning controls for the failure scenarios.

Cyclops, introduced in this paper, is an open research platform for everyone who wants to validate novel ideas and approaches in self-driving heavy-duty vehicle platooning. The platform consists of multiple 1/14 scale semi-trailer trucks equipped with associated computing, communication and control modules that enable self-driving on our scale proving ground. The perception system for each vehicle is composed of a lidar-based object tracking system and a lane detection/control system. The former maintains the gap to the leading vehicle, and the latter maintains the vehicle within the lane by steering control. The lane detection system is optimized for truck platooning, where the field of view of the front-facing camera is severely limited due to a small gap to the leading vehicle. This platform is particularly amenable to validating mitigation strategies for safety-critical situations. Indeed, the simplex architecture is adopted in the computing modules, enabling various fail-safe operations. In particular, we illustrate a scenario where the camera sensor fails in the perception system, but the vehicle is able to operate at a reduced capacity to a graceful stop. Details of Cyclops, including 3D CAD designs and algorithm source codes, are released for those who want to build similar testbeds.

Virtual coupling, which refers to the operation of railway vehicles that enables the merge and separation of vehicles on the move by controlling the gap between the vehicles without any mechanical coupling, is one of the technologies for increasing the transport capacity and enhancing operational efficiency. This paper proposes a robust gap controller based on sliding mode control with a nonlinear train model with uncertainties. Additionally, a gap reference generation scheme is developed that ensures that the merge and separation of two trains is completed before a given location and respects constraints on acceleration and jerk. The position and velocity measurement errors arising from imperfect knowledge of wheel diameters are also considered, and a new error correction scheme is proposed to reduce the perturbation in the gap control performance. The proposed schemes are validated through simulations.

Storage I/O performance remains a key factor that determines the overall user experience of a computer system. This is especially true for mobile systems as users commonly browse and navigate through many high-quality pictures and video clips stored in their device. The appetite for more appealing user interface has continuously pushed the mobile storage interface speed up; emerging UFS 2.0 standard provisions a maximum bandwidth of as high as 1,200 MB/s. In this work, we propose, design, and implement a mobile storage architecture that leverages the high-speed DRAM interface for communication, thus substantially expanding the storage performance headroom. In order to effectively turn the existing DRAM interface into a storage interface, we design a new storage protocol that runs on top of the DRAM interface. Our protocol builds on a small host interface buffer structure mapped to the system's memory space. Based on this protocol, we develop and fabricate a storage controller chip that natively supports the LPDDR3 interface. We also develop a host software stack (Linux device driver and boot loader) and a host platform board. Finally we show the feasibility of our proposal by constructing a full Android system running on the developed storage device and platform. Our detailed evaluation shows that the proposed storage architecture has very low protocol handling overheads and compares favorably to a UFS 2.0 device. The proposed architecture obviates the need for implementing a separate host-side storage controller on a mobile CPU chip.