Analysis of Naturalistic Electric Bike Rider Behavior: Energy and Power Considerations Authors: Noelani Fishman, Breanna Piercy Affiliation: Kwaku Boakye, Dr. Chris Cherry, and Dr. Shashi Nambisan SPONSORS: University of Tennessee, CURENT Engineering Center ACKNOWLEDGEMENTS: Kwaku Boakye, Dr. Shashi Nambisan, Dr. Chris Cherry Background ●Electric bikes are a more recent mode of active transportation ●UTK began the first ever e-bike share program (UT cycleUshare) in the US in 2012 ○Was led by Dr. Chris Cherry ○Several studies are conducted based on this research ○Social preferences concerning biking, walking, and e-biking in relation to a subject’s body type, exercise levels, and heart rate were studied Conclusion ●This project proved the already assumed idea that e-bike riders exert less power than regular bike riders. ●The bike rider with full electrical assistance on average exerted about half the power of the rider of the regular bike. ●The e-bike rider had a greater cadence, or RPM (revolutions per minute) ●The rider with electrical assistance obtained greater speeds than the rider with no assistance. The Future Further research can be done concerning e-bikes, including the following: ●An analysis of the amount of battery power used during the course of an e- bike ride. ●Research on how to optimize the efficiency of e-bike battery usage relative to the terrain. ●Develop new types of e-bike batteries that are cheaper, more efficient, and charge quicker. Results Naturalistic data were collected using GPS devices for two riders o Rider 1: An e-bike with full electrical power o Rider 2: Regular bike Four days of data collection for a period 1- 2 hours on each day along different paths as shown in Figure 2 Data were analyzed using GoldenCheeta software and Microsoft Office Excel The power exerted by riders was determined using the principles of bicycle science as shown equations 1 and 2. W=V[K(V+V w )²+mg(S+C r )] …..eq. 1 C r =0.005{1+2.1/P[1+(V/29)²]} …...eq. 2 where W = Power, K = Aerodynamic drag factor (kg/m), V = Speed relative to ground (m/s), Vw = Headwind velocity (m/s), m = Rider + bicycle mass (kg), g = Acceleration due to gravity, S = Slope of hill ( % Grade), Cr = Rolling resistance coefficient, P = tire pressure Figure 2: Sample of layout of bicycle trail during data collection Methodology Figure 3: Energy-use/power exerted by each rider Battery Figure 1: This is an example of the e-bike used during the research Figure 4: Sample of data from the GPS devices Results of the data are shown in Figures 3 and 4 ●Regular bicycle rider yields about double the amount of energy than the e-biker ○Speed of the e-bicycle was greater ○Cadence of e-bike was also higher ○Ratio of power per cadence was higher for regular biker ●Speed of biker relative to the ground increased as altitude decreased ●Each day data varied due to the difficulty of the terrain, exhaustion, temperature, and other factors ●Results showed that e-bikes travel faster and farther with more ease than regular bikes Abstract Electric bikes (e-bikes) were developed to provide hybrid human/electrical power to help propel riders. Studies determining how much power is exerted by riders of e- bikes are limited. This study attempts to quantify and compare the overall energy-use of riders of e-bikes and regular bicycles using fundamental physics relationship with real-world data. Data from naturalistic bicycling behaviors of two riders (one with e-bike and the other with regular bike) were obtained using GPS devices. Analysis of the data showed that the e-bike rider, on average, exerted about half the power used by the rider of the regular bike.