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Mechanical Engineering. 2017;139(12):S3-S7. doi:10.1115/1.2017-Dec-7.
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This article discusses how connected cooperative control of autonomous vehicles (AVs) can help in providing safe and comfortable mobility during unexpected road situations. Driving AVs in urban areas poses a big challenge due to the complexity of the traffic rules as well as unexpected scenarios involved. In these situations, an inter-vehicle communication system can be of great help. Cooperation between multiple AVs is possible with the development of vehicular communication. In particular, state estimation can be improved with multiple sources of information gathered from different vehicles. Cooperative state estimation can also improve robustness against communication failure. With future trajectories shared among nearby vehicles, the motion can be coordinated to make navigation safer and smoother for AVs. For vehicular communication, the IEEE 802.11p standard has been designed to allow information exchange between high-speed cars, and between vehicles and roadside infrastructure. Other wireless communication technologies, such as 3G, 4G, and WiFi, are also suggested.

Topics: Vehicles , Roads , Traffic , Cities
Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2017;139(12):S8-S12. doi:10.1115/1.2017-Dec-8.
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This article discusses past, present, and future research on connected automated vehicles and their impact on road transportation. From the 1980s, microcontrollers started to penetrate production vehicles through various subsystems such as engine control units, and anti-lock braking systems. Soon the need for different microcontrollers to communicate with each other led to the invention of the controller area network bus. In the 1990s, onboard sensors were introduced to monitor the environment and the motion of neighboring vehicles. These sensors, combined with more powerful computers, allowed vehicles to perform lateral and longitudinal control such as lane keeping and car following. Starting from the mid-2000s, wireless communication technologies such as WiFi and 4G/LTE have been adopted in order to facilitate vehicle-to-vehicle and vehicle-to-infrastructure communication. These are often referred to as vehicle-to-everything (V2X) communication, where X also includes pedestrians, bicyclists, etc. In particular, in the United States, dedicated short-range communication has been standardized based on IEEE 802.11p protocol, which allows low-latency, ad-hoc, and peer-to-peer communication with 10-Hz update frequency.

Topics: Vehicles , Traffic
Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2017;139(12):S13-S16. doi:10.1115/1.2017-Dec-9.
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This article elaborates the approaches that can be used to verify an autonomous vehicle (AV) before giving it a driver’s license. Formal methods applied to the problem of AV verification include theorem proving, reachability analysis, synthesis, and maneuver design. Theorem proving is an interactive technique in which the computer is largely responsible for demonstrating that the model satisfies the specification, with occasional help from the user. The latter provides lemmas and axioms that the tool leverages to advance the proof towards its conclusion. Reachability analysis is used to verify the operation of the AV during navigation. This provides an extension of onboard diagnostics to whole-AV operation, where the diagnosis does not concern one component’s requirements, but the safety of the entire AV. Another approach is to design correct-by-construction controllers from preverified maneuvers. The basic idea is that one builds a library of maneuvers, such as Left-Turn and Right-Turn, and verifies that the car can perform these maneuvers from any initial state.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2017;139(12):S17-S20. doi:10.1115/1.2017-Dec-10.
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This article provides an overview of the potential attacks that can impact connected vehicles (CV) technologies and highlights how a resilient control scheme can be effective to mitigate the effect of these attacks by allowing the system to safely operate with reduced performance. CVs endure several challenges that can occur due to cyberattacks with purposes of disrupting the performance of the connected vehicles system. To improve safety and security, advanced vehicular control systems must be designed to be resilient to cyberattacks. The attack detection and switching strategy is formulated as an MPC-like optimization problem, where the control variable is constrained to a specific strategy and applied in a receding horizon fashion. The choice of the cost function plays an important role in the performance of the system. The results of the switching strategy show that in comparison with the perfect case—in which the attacks are perfectly identified and the correct strategy selected immediately—there is approximately a 22 percent strategy improvement that could still be achieved by changing the switching strategy.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2017;139(12):S21-S23. doi:10.1115/1.2017-Dec-11.
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This article presents an overview of the research and educational programs for connected and autonomous vehicles at the University of Waterloo (UWaterloo). UWaterloo is Canada’s largest engineering school, with 9,500 engineering students and 309 engineering faculty. The University of Waterloo Centre for Automotive Research (WatCAR) for faculty, staff and students is contributing to the development of in-vehicle systems education programs for connected and autonomous vehicles (CAVs) at Waterloo. Over 130 Waterloo faculty, 110 from engineering, are engaged in WatCAR’s automotive and transportation systems research programs. The school’s CAV efforts leverage WatCAR research expertise from five areas: (1) Connected and Autonomous; (2) Software and Data; (3) Lightweighting and Fabrication; (4) Structure and Safety; and (5) Advanced Powertrain and Emissions. Foundational and operational artificial intelligence expertise from the University of Waterloo Artificial Intelligence Institute complements the autonomous driving efforts, in disciplines that include neural networks, pattern analysis and machine learning.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2017;139(12):27-29. doi:10.1115/1.2017-Dec-1.
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This article explains how difficult it could be sometimes to get a potentially good idea from the laboratory to the marketplace. A classic example of this difficulty is the humble Post-it note that was developed by engineer and inventor Art Fry. Art Fry worked for the 3M Company, which allowed him to engage part time in intrapreneurship. When Fry approached his superiors with his invention, the novel idea was not received with much enthusiasm. The market for sticky bookmarks did not seem to be very promising, and Fry’s idea seemed outlandish. However, Fry persistently pushed the idea until 3M relented and test-marketed “temporarily permanent” stick-and-remove notes, pads of which were distributed free to customers of other office products. Secretaries and other office workers found all sorts of uses for what came to be called Post-it notes, and the rest is history for the immensely successful product. However, the whole process from development to commercialization spanned about a decade.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2017;139(12):31. doi:10.1115/1.2017-Dec-2.
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This article presents an overview of the bionic limbs designed by Hugh Herr. They include the powered foot and ankle prostheses with multiple tendon-like actuators that stiffen and power gait. Each ankle holds three computers that perform various computations enabling one to walk at different speeds across different terrains. They were distinct in the prostheses world because these bionic limbs are powered, while all other foot ankle prostheses are energetically passive. In effect, Herr has to mimic the mechanism of a natural limb. The bionic limb is running spinal-like reflexes on a computer chip. A commercial product—called emPOWER—is being sold through Herr’s startup called BioneX Medical Technologies. In the lab, Herr and his colleagues are working on developing neural interfaces, essentially connecting the bionic limbs to muscles and nerves so a person can think and move the limbs and also feel the movement as a feedback into the nervous system.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2017;139(12):33. doi:10.1115/1.2017-Dec-3.
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This article presents an overview of the EyeQ silicon chip developed by Jerusalem-based company Mobileye. The company has been designing hardware and training software algorithms to help vehicles detect and avoid other vehicles. In a major advance, the company has been able to shrink its Advanced Driving Assist System to fit on a single silicon chip it calls EyeQ. When wired to a camera, the system offers superior cruise control, keeps its vehicle in lane, recognizes traffic signs, and can automatically brake for pedestrians and other dangerously close vehicles. The company, which was founded by Amnon Shashua, a professor of computer science at the Hebrew University of Jerusalem, has already sold 20 million of its chips. The advantage of having so many of them already traveling the world’s highways extends beyond the immediate safety they provide. Mobileye is mining the data those chips collect to create a high-definition mapping system that will work with real-time data to help vehicles navigate and eventually become fully autonomous.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2017;139(12):35. doi:10.1115/1.2017-Dec-4.
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This article describes the basic features of a 3D printed blade that can survive inside a turbine. This blade has been developed by Siemens. The team behind the blade included project manager, Jenny Nilsson, as well as engineers at Material Solutions, a company Siemens later bought. Team members developed better cooling designs to improve the gas turbine efficiency, designed the blade, and developed the whole manufacturing process to manufacture this type of component and geometry. Like all additive manufacturing, the team applied thin layers of material—one after the other—to build up a finished object. The main difference with Siemens’ blade process was that layers were made of high-temperature-resistant, polycrystalline nickel-based superalloy powder, which was then heated and melted by a laser. The durability of the printed blades was proved by installing them in a 13-MW SGT-400-type industrial gas turbine at a Siemens test center for industrial gas turbines in Lincoln, United Kingdom.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2017;139(12):37. doi:10.1115/1.2017-Dec-5.
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This article discusses the technology used at the John W. Turk Jr. Power Plant in Fulton, Ark., to tackle the challenges of raising the pressure and temperature of the steam to new heights. The Turk plant is the first in the United States where the final steam conditions exceed both the critical pressure and a temperature of 1,100°F. Operating as an ultrasupercritical boiler, the Turk plant has the highest net plant efficiency of any solid fuel power plant in the United States. In this plant, Southwestern Electric Power Company tapped Babcock & Wilcox to design, supply, and erect the 600-MW advanced supercritical steam generator. To best optimize efficiency, the design team selected a single reheat cycle with elevated steam pressure and temperature. Babcock & Wilcox engineers also employed computational fluid dynamics modeling to place burners and overfire air ports to make the best use of low-sulfur coal.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2017;139(12):39. doi:10.1115/1.2017-Dec-6.
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This article explains how Tesla batteries are making electric vehicles (EVs) affordable for customers. Tesla’s battery revolution began when CEO Elon Musk declared that it would sell a mass-market EV for just $35,000. To produce battery packs cheaply enough to reach that price point, Tesla reengineered not only the production process, but also the factory in which the batteries are made. The Reno, Nev., Gigafactory is not yet operating at full capacity, but it is expected to produce 35 GW per year of lithium-ion batteries, about double the present-day global production. Tesla partnered with Panasonic to revamp the production process, and ended up redesigning the chemistry of the battery itself. The standard “18-650” cell format used thousands of less-expensive commodity cells, similar to lithium-ion batteries used in laptop computers. Tesla replaced individual safety systems built into each cell with an inexpensive fireproof system for the entire battery pack. Now, they have begun producing the new “2170” cell, which delivers higher density through an automated system developed with Panasonic to further reduce costs.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2017;139(12):46-47. doi:10.1115/1.2017-Dec-12.
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This article discusses how advancement in turbine cooling techniques has helped enhancing the performance and endurance of turbines. Gas turbine thermal efficiencies increase with higher temperatures of the gas flow exiting the combustor and entering the work-producing component—the turbine. The fundamental aim of a turbine heat transfer designer is to obtain the highest overall cooling effectiveness for a blade or vane, with the lowest possible penalty on thermodynamic performance. In the last 50 years, advances have led to an overall increase in turbine and vane cooling effectiveness, from 0.1 to 0.7. It started with convection only and has progressed with film cooling, thermal barrier coatings, and new materials and architectures. Temperature excesses in turbines are now as high as 1400°F (778°C) above alloy melting points. Film cooling is the key to attaining these levels, and to increasing them in the future, for yet higher gas turbine efficiencies.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2017;139(12):48-50. doi:10.1115/1.2017-Dec-13.
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This article presents an overview of GE’s HA gas turbines that represent the most reliable and efficient machines in the world for converting natural gas into electricity. In a combined cycle arrangement, these turbines provide cost-effective and clean generation that offers reliable electricity to an expanding, global population. The 7/9HA turbine is based upon the original H-class 4-stage gas turbine with exception of simplification by eliminating steam cooling. Metals chosen for the 7/9HA are proven alloys with over 50 million hours of operation on F- and H-class gas turbines. The first 9HA.01 entered commercial operation on June 17, 2016 at the Électricité de France Bouchain plant, located in the Nord Pas-de-Calais region of France. GE followed the Guinness Book of World Records’ definition for a consistent and traceable operating condition for establishing efficiency in world records. Under the oversight of Guinness World Records staff, GE set the record for the world’s most efficient combined-cycle power plant with an efficiency of 62.22% while producing more than 605 MW of electricity.

Commentary by Dr. Valentin Fuster

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