0
Research Papers

A Dynamics-Based Hazard Analysis of Inverted-Pendulum Human Transporters Using Data-Mined Information

[+] Author and Article Information
William Singhose

The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology,
Atlanta, GA 30332-0405
e-mail: Singhose@gatech.edu

Christopher Adams, Dooroo Kim

The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology,
Atlanta, GA 30332-0405

Manuscript received January 29, 2015; final manuscript received January 1, 2016; published online July 1, 2016. Assoc. Editor: Chimba Mkandawire.

ASME J. Risk Uncertainty Part B 2(3), 031007 (Jul 01, 2016) (12 pages) Paper No: RISK-15-1008; doi: 10.1115/1.4032459 History: Received January 29, 2015; Accepted January 06, 2016

When a product is a complex dynamic system that interacts directly with a human, engineers must consider a wide range of possible motions and forces that the device could exert on the human. Such an analysis goes beyond a simple thought exercise and requires detailed knowledge about the system dynamics and the operating environment. This paper presents such an analysis of inverted-pendulum human transporters. The list of hazards is constructed by using knowledge of the dynamics and mechanical design obtained through simulation and experimentation. However, the dynamics are so complex that the list is augmented with hazards that are revealed by studying accident videos posted on the Internet. The severity of the hazards is estimated using an energy-based measurement of the hazard onset conditions as well as compounding factors from the mechanical design. In addition, experimental and simulation results of sample hazard conditions illustrate their danger and severity. The analysis reveals that inverted-pendulum human transporters have several hazards with unacceptable risk.

Copyright © 2016 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Two-wheeled inverted-pendulum human transporters: (a) Segway i167, (b) Segway i2, and (c) Ninebot personal transporter

Grahic Jump Location
Fig. 2

Schematic diagram of an inverted-pendulum human transporter

Grahic Jump Location
Fig. 3

Hazard analysis flowchart

Grahic Jump Location
Fig. 4

Segway roll instability

Grahic Jump Location
Fig. 5

Segway forward speed, yaw rate, and base roll angle during a roll-unstable turn [24]. (a) Forward speed, (b) yaw rate, and (c) base roll angle

Grahic Jump Location
Fig. 6

Segway speed and orientation during a single-wheel obstacle collision [24]. (a) Segway speeds and (b) Segway orientation angles

Grahic Jump Location
Fig. 7

Segway i167 twist-steering grip

Grahic Jump Location
Fig. 8

Segway angular response due to unexpected steering-grip twist when leaning forward [24]

Grahic Jump Location
Fig. 9

Segway yaw rate response with right wheel slip on a medium-friction surface [24]

Grahic Jump Location
Fig. 10

Segway right wheel blocking rider’s foot

Grahic Jump Location
Fig. 11

Rider’s feet trapped by wheel

Grahic Jump Location
Fig. 12

Segway moving without a rider in balance mode

Grahic Jump Location
Fig. 13

Segway handlebar blocking rider’s arm

Grahic Jump Location
Fig. 14

Rider in a seated position on the Segway base

Grahic Jump Location
Fig. 15

One wheel of a transporter colliding with an obstacle. (a) Transporter traveling toward an obstacle. (b) Transporter turns toward obstacle, while the rider’s momentum carries him forward.

Grahic Jump Location
Fig. 16

Total energy of rider versus speed

Grahic Jump Location
Fig. 17

Total energy of rider versus additional fall height when traveling at 5.59 m/s (12.5 mph)

Grahic Jump Location
Fig. 18

Total energy of rider as a function of speed and additional fall height

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Articles from Part A: Civil Engineering
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In