Alternative Problem Set 2

Reconstruction of acceleration data

Total points: 30

Due: Friday February 17 7pm CET

Format: IPython Notebook or python program

The purpose of this problem set is to use acceleration data to reconstruct motion. Such data can be obtained using the sensors in standard (smart) mobile phones.

The data you should use is

data/autofahrt.txt

The data were obtained in a car, with the mobile phone in a fixed position, facing forward. The car started from zero velocity, accelerated towards a roundabout, circled around it once and returned along the street it came. Note this data set has been recorded at relatively low time resolution.

Please take care to produce readable code that uses functions and numpy arrays as appropriate.

Part 1 - Integration the forward acceleration

(12 points)

Start by reading in the acceleration data shown above, and plot it with Matplotlib.

Then, calculate and plot the projected forward distance traversed by the mobile phone as a function of time.

Part 2 - Coordinate Systems

(8 points)

Work out the acceleration vector in the laboratory system.

Part 3 - Visualizing the track

(10 points)

Integrate the acceleration in the laboratory system and plot the track. Does your result correspond to the above description?

Discuss the (possible) limitations of your code and the impact of sparse time sampling.