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Automated Vehicle Disengagement Reaction Time Compared to Human Brake Reaction Time in Both Automobile and Motorcycle Operation

Dynamic Analysis Group LLC-Jeffrey T. Dinges, Nicholas J. Durisek
Published 2019-04-02 by SAE International in United States
Autonomous Vehicle Disengagement Reports have been published by the California Department of Motor Vehicles since 2015. The State of California autonomous vehicle testing regulations require every manufacturer authorized to test autonomous vehicles on public roads to submit an annual report summarizing disengagements. In early versions of the annual report, automated vehicle manufacturers were required to provide the time that it took for a human driver to take manual control of the vehicle when reporting vehicle disengagements. This study analyzes reported automated vehicle disengagement reaction times from 2015 through 2017 for various manufacturers that provided information to the California Department of Motor Vehicles while operating vehicles in autonomous mode. This study compares the reported automated vehicle operation disengagement reaction time to field literature in testing and experimentation on human brake reaction times for both automobile and motorcycle operation.
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Motorcycle Lean Angle Variation around a Constant Radius Curve at Differing Speeds and Travel Paths with an Evaluation of Data Measurement Systems

SEA, Ltd.-Ronny Wahba, Thomas Timbario, Jonathan Nelson, Fawzi Bayan, Dalton Jordan, Jonathan Swanson, Ashley Dunn
Published 2019-04-02 by SAE International in United States
Recent studies evaluating motorcycle lean angle have compared theoretical lean angle equations with real-world-tested motorcycle lean angles. These studies have considered several factors affecting lean angle, including the simplified assumptions made when calculating theoretical lean angles, the speed of the motorcycle around a curve, and the geometry of the roadway/curve. This study further evaluates motorcycle lean angle as a function of speed, but primarily focuses on the effects of different travel paths selected by the rider around the same constant radius curve. The testing incorporates nine passes around the same curve traveling three different paths at three different speeds. The real-world-tested lean angles were compared to the predicted calculated lean angles for each tested travel path and speed. The theoretical lean angles were calculated using the graphically reconstructed radius of curvature generated through three-dimensional (3D) laser scans of the roadway and aerial video footage and orthomosaic imagery. The orthomosaic imagery was collected via small Unmanned Aerial Vehicle (sUAV) (commonly referred to as a drone). The analyzed curve is a sweeping constant radius left-hand curve with…
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Analysis of Whole Body Vibration of a Two-Wheeler Rider

NIT Rourkela-Kashish Veda Eluri, Vadde Lokesh Reddy, Murugan Sivalingam, Balaji PS
Published 2019-04-02 by SAE International in United States
Two-wheel motorcycles are preferred in many countries as they have some merits such as cheaper, easy to handle and give higher fuel economy compared to three and four-wheel vehicles. Majority of the population in India falls under low and middle-income groups. Two-wheelers cater to the needs of low and middle-income users, and fill the gaps when public transport systems are inefficient or not available. Most of the people in India use motorcycles for transportation. However, due to different road conditions, motorcycle rider experiences different health effects within a few years of their vehicle travel. This paper investigates the effect of vibration on a man commuter’s health. For this purpose, a mathematical model of a male rider’s body was considered, and a numerical analysis was carried out to assess the effect of vibration acting on the commuter during a two-wheeler ride under various road conditions for a chosen suspension system and presented in this paper. Road conditions were chosen based on the different surface roughness values. The most affected rider’s body part due to the vibration…
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Behavior of Electric Scooter Operators in Naturalistic Environments

Exponent Failure Analysis-Jay Todd, David Krauss, Jacqueline Zimmermann, Amber Dunning
Published 2019-04-02 by SAE International in United States
The use of electric scooters (e-scooters), which are more generally categorized as motorized scooters, has undergone explosive growth owing to “scooter share” programs in which an e-scooter is rented for a limited period of time. The near-spontaneous ubiquity of e-scooters has prompted government and scooter share companies to address issues partly motivated by concerns related to the inclusion of a large population of e-scooters into vehicular traffic. These issues are influenced by the decisions and behaviors of the scooter operators, who, despite being licensed to drive passenger vehicles, potentially have limited experience operating an e-scooter in the presence of traffic. E-scooters are in a relative unique position where they are small enough to negotiate pedestrian traffic, yet fast enough to travel on roadways. This enables an e-scooter operator to change when and where he rides, e.g., from traveling on a sidewalk to riding in a clear traffic lane in order to avoid a group of pedestrians standing at an intersection. Such changes may catch nearby motorists off-guard, thereby increasing the risk of a collision with…
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An Analysis of Sport Bike Motorcycle Dynamics during Front Wheel Over-Braking

Momentum Engineering Corp.-Edward Fatzinger, Jon Landerville, Jeffrey Bonsall, Daniel Simacek
Published 2019-04-02 by SAE International in United States
There is extensive literature on motorcycle skid/brake to stop testing on a host of motorcycle types, rider experience, brake system configurations and the associated deceleration rates. Very little information exists on deceleration rates involved with over-braking the front wheel. The subject of this paper addresses the deceleration rates of sport bike type motorcycles during over-braking of the front wheel. Based on the physics of a two-wheeled vehicle like the motorcycle, once the front wheel is over-braked and becomes locked, the rider has very little time to recover from the skid and often times falls. Another over-braking scenario, especially on sport bike type motorcycles, is the possibility of the rear wheel lifting and pitching over the front wheel. During the initial phase of braking, weight transfer to the front wheel occurs creating a greater level of traction. As the motorcycle begins to fall or pitch over, the weight on the front wheel decreases significantly and therefore the frictional force decreases significantly as well. The goal of this publication was to perform maximum front wheel brake testing…
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Analyzing the Limitations of the Rider and Electric Motorcycle at the Pikes Peak International Hill Climb Race

Brunel University-Koen Matthys
Eric Wu Engineering-Eric Wu
Published 2019-04-02 by SAE International in United States
This paper describes a post-race analysis of team KOMMIT EVT’s electric motorcycle data collected during the 2016 Pikes Peak International Hill Climb (PPIHC). The motorcycle consumed approximately 4 kWh of battery energy with an average and maximum speed of 107 km/h and 149 km/h, respectively. It was the second fastest electric motorcycle with a finishing time of 11:10.480. Data was logged of the motorcycle’s speed, acceleration, motor speed, power, currents, voltages, temperatures, throttle position, GPS position, rider’s heart rate and the ambient environment (air temperature, pressure and humidity). The data was used to understand the following factors that may have prevented a faster time: physical fitness of the rider, thermal limits of the motor and controller, available battery energy and the sprocket ratio between the motor and rear wheel. Even though the rider’s heart rate implied a vigorous exercise intensity level, throttle values indicated that the rider wanted to go faster ~33% of the time. The motor reached a steady-state temperature that was approximately 30°C below the maximum allowable temperature and thus could have handled…
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Motorcycle Accelerations while Successfully Traversing Roadway Irregularities and Traffic Calming Devices (Speed Bumps) at Small Lean Angles

SEA, Ltd.-Ronny Wahba, Jonathan Nelson, Thomas Timbario, Dalton Jordan, Fawzi Bayan, Edward Adams III, Ashley Dunn
Published 2019-04-02 by SAE International in United States
There have been limited empirical studies regarding the dynamics of a motorcycle and rider as a motorcycle traverses a roadway irregularity such as a pothole or depression, or a traffic calming device (TCD) such as a speed bump. This study seeks to establish qualitative analysis of the success of motorcycles traversing various roadway irregularities/TCDs as well as quantitatively analyzing accelerations to the motorcycle at varying speeds and lean angles. Further analysis is conducted comparing the accelerations experienced in scenarios where the suspension of the motorcycle experiences extension followed by compression, as is the case when encountering a pothole or depression, as well as scenarios where the suspension of the motorcycle experiences compression followed by extension, as is the case when encountering a TCD. Largely, the study is to establish minimum values for both speeds and lean angles in which traversing roadway irregularities\TCDs of a given geometry causes little to no dynamic instability to the motorcycle and little to no discomfort to the rider. The roadway irregularities/TCDs are traversed perpendicularly and at varying lean angles. Roadway…
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Braking and Swerving Capabilities of Three-Wheeled Motorcycles

Kineticorp LLC-Nathan Rose, Neal Carter, William Neale, Nathan Mckelvey
Published 2019-04-02 by SAE International in United States
This paper reports testing and analysis of the braking and swerving capabilities of on-road, three-wheeled motorcycles. A three-wheeled vehicle has handling and stability characteristics that differ both from two-wheeled motorcycles and from four-wheeled vehicles. The data reported in this paper will enable accident reconstructionists to consider these different characteristics when analyzing a three-wheeled motorcycle operator’s ability to brake or swerve to avoid a crash. The testing in this study utilized two riders operating two Harley-Davidson Tri-Glide motorcycles with two wheels in the rear and one in the front. Testing was also conducted with ballast to explore the influence of passenger or cargo weight.Numerous studies have documented the braking capabilities of two-wheeled motorcycles with riders of varying skill levels and with a range of braking systems. The results reported here showed that when both the front and rear brakes are utilized, the decelerations produced during braking are consistent with, but in the upper half of, the range of decelerations previously reported for two-wheeled motorcycles. Studies of two-wheeled motorcycles commonly report that most of the deceleration is…
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Rider Stature Influence to Injury Risk in Motorcycle Rear Impact to Car

Tianjin University of Science and Technology-Wenle Lv
University of West Bohemia-Ludek Hyncik, Tomasz Bonkowski
Published 2019-03-25 by SAE International in United States
Road traffic accidents cause one of the highest numbers of severe injuries. Approximately 1.25 million people die each year as a result of road traffic crashes and between 20 and 50 million more people suffer non-fatal injuries, with many incurring a disability. Nearly half of those dying on the roads are so-called vulnerable road users, namely pedestrians, cyclists and two-wheeler riders including motorcyclists. Those vulnerable road users usually undergo complex kinematics and complex loading caused by the other vehicle impact.Virtual human body biomechanical models play an important role to assess the injuries during the impact loading especially for scenarios, where complex dynamical loading is taken into account. An additional benefit of some virtual human models is their scalability, so that they can assess the injury risk for the particular subject taking into account a wide spectrum of the whole population.The presented work shows the motorcycle rider injury risk analysis during the rear motorcycle accident to the car using the virtual approach by the numerical simulation taking into account the variability of the human body. The…
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Autonomy for the Masses

Autonomous Vehicle Engineering: March 2019

Lindsay Brooke
  • Magazine Article
  • 19AVEP03_04
Published 2019-03-01 by SAE International in United States

Ford Autonomous Vehicles LLC aims to do for AVs what the Model T did for just about everyone. CEO Sherif Marakby explains.

Henry Ford was not quite a year away from rolling out his world-changing Model T when, in 1907, the Chicago Hosiery Co. built a factory branch in Detroit's Corktown district. Today the exterior of that same three-story brick building on Michigan Ave. appears unchanged from its sock-sewing past, aside from the Spin electric scooters on the front sidewalk. But inside, it's abuzz with the innovative stuff that a 21st-century Henry would love.

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