Study title

United Kingdom

Other

A Typhoon II electric wheelchair (Invacare Corporation, Elyria, OH) was operated through five different tasks while acquiring the current used from the battery pack and while recording the rotational speed of the wheels. Eight different adult participants repeated each surface three times, each time is called a trial. Participants had no previous experience operating an electric wheelchair. Current was used to calculate power and rotational speed to calculate speed of the wheelchair. This data article presents the power and speed of the Typhoon II electric wheelchair while being operated through: cross slope 2.5%, cross slope 4%, ascending slope 6.1%, ascending slope 12%, flat surface. Power data was first filtered with a moving average filter with a window size of 100 and then low pass filtered with a zero phase 5th order Butterworth algorithm with a 1 Hz cut off frequency. Custom-built MATLAB scripts were implemented for analysis (R2015A The MathWorks Inc, MA, USA). The distance travelled was calculated from the wheels’ rotational speed. The wheelchair speed was calculated from the distance travelled and low pass filtered with a zero phase 5th order Butterworth algorithm with a 1 Hz cut off frequency.Mean (M) and maximum (Mmax) power for each trial, each participant and each task were computed. Then mean power (Mp) for each task was calculated by averaging the results across all trials and participants for each task. The latter represents the target values against which microtrips from each participant were measured in order to identify the most representative one. Median Absolute Deviation (MAD) between M for each participant and Mmax was calculated. The smallest MAD value for each task was chosen as the representative microtrip. The chosen microtrips were then combined based on a selected distance covered by the wheelchair. The total distance covered was arbitrarily set to approximately 66 m (216.5 ft). Integers from 1 to 5 were assigned to each task and a series of randomly generated numbers were used for the combination. The power cycle was constructed from the selected microtrips put together in the randomly generated order. A drive cycle was calculated from the speed calculated based on the distance travelled by the wheelchair through well-established vehicle dynamics equations.