The experiments have been carried out with a group of 30 volunteers within an age bracket of 19-48 years. Each person performed six activities (WALKING, WALKING_UPSTAIRS, WALKING_DOWNSTAIRS, SITTING, STANDING, LAYING) wearing a smartphone (Samsung Galaxy S II) on the waist. Using its embedded accelerometer and gyroscope, we captured 3-axial linear acceleration and 3-axial angular velocity at a constant rate of 50Hz. The experiments have been video-recorded to label the data manually. The obtained dataset has been randomly partitioned into two sets, where 70% of the volunteers was selected for generating the training data and 30% the test data.
The sensor signals (accelerometer and gyroscope) were pre-processed by applying noise filters and then sampled in fixed-width sliding windows of 2.56 sec and 50% overlap (128 readings/window). The sensor acceleration signal, which has gravitational and body motion components, was separated using a Butterworth low-pass filter into body acceleration and gravity. The gravitational force is assumed to have only low frequency components, therefore a filter with 0.3 Hz cutoff frequency was used. From each window, a vector of features was obtained by calculating variables from the time and frequency domain.
For each record in the dataset it is provided:
- Triaxial acceleration from the accelerometer (total acceleration) and the estimated body acceleration.
- Triaxial Angular velocity from the gyroscope.
- A 561-feature vector with time and frequency domain variables.
- Its activity label.
- An identifier of the subject who carried out the experiment.
- subject
- Activity_Label
- timeBodyAccMean-X
- timeBodyAccMean-Y
- timeBodyAccMean-Z
- timeBodyAcc-std-X
- timeBodyAcc-std-Y
- timeBodyAcc-std-Z
- timeGravityAccMean-X
- timeGravityAccMean-Y
- timeGravityAccMean-Z
- timeGravityAcc-std-X
- timeGravityAcc-std-Y
- timeGravityAcc-std-Z
- timeBodyAccJerkMean-X
- timeBodyAccJerkMean-Y
- timeBodyAccJerkMean-Z
- timeBodyAccJerk-std-X
- timeBodyAccJerk-std-Y
- timeBodyAccJerk-std-Z
- timeBodyGyroMean-X
- timeBodyGyroMean-Y
- timeBodyGyroMean-Z
- timeBodyGyro-std-X
- timeBodyGyro-std-Y
- timeBodyGyro-std-Z
- timeBodyGyroJerkMean-X
- timeBodyGyroJerkMean-Y
- timeBodyGyroJerkMean-Z
- timeBodyGyroJerk-std-X
- timeBodyGyroJerk-std-Y
- timeBodyGyroJerk-std-Z
- timeBodyAccMagnitudeMean
- timeBodyAccMagnitudeStdDev
- timeGravityAccMagnitudeMean
- timeGravityAccMagnitudeStdDev
- timeBodyAccJerkMagnitudeMean
- timeBodyAccJerkMagnitudeStdDev
- timeBodyGyroMagnitudeMean
- timeBodyGyroMagnitudeStdDev
- timeBodyGyroJerkMagnitudeMean
- timeBodyGyroJerkMagnitudeStdDev
- freqBodyAccMean-X
- freqBodyAccMean-Y
- freqBodyAccMean-Z
- freqBodyAcc-std-X
- freqBodyAcc-std-Y
- freqBodyAcc-std-Z
- freqBodyAccMeanFreq-X
- freqBodyAccMeanFreq-Y
- freqBodyAccMeanFreq-Z
- freqBodyAccJerkMean-X
- freqBodyAccJerkMean-Y
- freqBodyAccJerkMean-Z
- freqBodyAccJerk-std-X
- freqBodyAccJerk-std-Y
- freqBodyAccJerk-std-Z
- freqBodyAccJerkMeanFreq-X
- freqBodyAccJerkMeanFreq-Y
- freqBodyAccJerkMeanFreq-Z
- freqBodyGyroMean-X
- freqBodyGyroMean-Y
- freqBodyGyroMean-Z
- freqBodyGyro-std-X
- freqBodyGyro-std-Y
- freqBodyGyro-std-Z
- freqBodyGyroMeanFreq-X
- freqBodyGyroMeanFreq-Y
- freqBodyGyroMeanFreq-Z
- freqBodyAccMagnitudeMean
- freqBodyAccMagnitudeStdDev
- freqBodyAccMagnitudeMeanFreq
- freqBodyAccJerkMagnitudeMean
- freqBodyAccJerkMagnitudeStdDev
- freqBodyAccJerkMagnitudeMeanFreq
- freqBodyGyroMagnitudeMean
- freqBodyGyroMagnitudeStdDev
- freqBodyGyroMagnitudeMeanFreq
- freqBodyGyroJerkMagnitudeMean
- freqBodyGyroJerkMagnitudeStdDev
- freqBodyGyroJerkMagnitudeMeanFreq