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Sensivity Analysis

This analysis computes the gradient of the vehicle energy consumption with respect to a set of user-defined parameters.

This analysis is very useful to understand the impact of each parameter on one of the key objectives of the project: reducing energy consumption.

The user shall list the parameters that will be varied and the percentage of variation. The software will calculate the mean variation over all routes. The calculation for variable is x(1+variance/100) and x(1-variance/100) to evaluate variation.

The Sensitivity analysis input file must have the following format.

You can download the template file and save it to your workspace. The content of this file is shown hereafter.

##########################
# SECTION 1: Analysis Type
analysis_type : Sensitivity analysis

################################
# SECTION 2: Analysis Parameters
# Finite difference order
# 1 = linear (default)
# 2 = quadratic
precision order: 1
# Calculation method
# Vector = all forces are calculated in the world CS and are vectors
method: Vector
# Include rotation inertia terms in the energy calculation
# True: rotational inertia terms are take into account
# False: rotational inertia terms are neglected (default)
# The inertia terms are generally small and can be nelected in most cases
Rotation inertia: False

###########################
# SECTION 3: Output Request
# Select output units. Available choices are:
# Energy: J = Joule, kWh = kilo Watt hour
# Power: W = Watt, kW = kilo Watt, HP = Horsepower
# Distance: m = meter, km = kilometer, mile = mile
units :
  Energy: kWh
  Power: kW
  Distance: km
# Would like to save results in a output file? If yes: save:true, If not: save:False
save: True
# Input the output folder where to save the result files
savedire: results_sensitivity
# Input the first part of the output file name. 
# The result file name will have following name: "file name"_"trajet"_"GPS track name".yaml
# savename: GPS_Replay_new
# Output details:
# 1 = normal (default)
# 2 = debug
out_level: 1


############################
# SECTION 4: Analysis inputs
# Directory where the GPS files are located
directory: Tracks

# list of GPX input
# You can also in the keyword "all" to take all GPX files found in the "directory" specified above.
gps_files :
  - trackExample.gpx

variance: 10 # variance in percentage [%] of the value

variable:
  - mass
  - Cx

# Input the vehicle characteristics
vehicle:
  mass: 405         # Total mass of the vehicle + driver + luggage in [kg]
  radius: 0.25        # Wheel radius in [m]
  Cx: 0.325            # Total vehicle Drag coefficient [dimensionless]
  Crr: 0.01          # Totale vehicule rolling resistance coefficient [dimensionless]

  S: 1.5               # vehicle aerodynamic cross section perpendicular to vehicle velocity in [m^2]
  nbr: 1             # Number of driving wheel
  V_int: 4      # Total interior volume of the vehicle [m^3]
  S_tot: 5           # Total exterior surface [m^2]

  P_headlight: 80    # Headlight power [W]
  dmdt: 0.05         # Flow rate of air through vents in [kg/s]
  ktherm: 10         # thermal conductivity coefficient in [W/m^2/K]
  T_int: 300         # intern temperature [K]
  T_ext: 280         # external temperature [K]

  I_sun: 1000     # Solar heat flux [W/m^2]
  S_windows: 2         # Glass total surface [m^2]
  A_windows: 0.6       # Glass absorption coefficient [dimensionless]

  n_motor: 1        # number of motors [dimensionless]
  efficiency_map: Valeo 415001  # file path to the motor efficiency map. The map is a torque - rotation velocity - efficiency map.

  transmission_ratio: 12         # Total transmission ratio between motor pulley and motorised wheel gear [dimensionless]
  eta_battery: 0.95 # Batterie efficiency [dimensionless]
  eta_transmission: 0.96 # transmission axe efficiency [dimensionless]
  eta_motordrive: 0.96 # onduleur efficiency [dimensionless]
  R_int: 0.08       # internal batterie resistance in [ohm]

  Inertia_Mat: # Inertia matrix of the sprung mass, in the vehicle coordinate system [kg.m^2]
  - [44, 2, 2]
  - [2, 72, 2]
  - [2, 2, 80]
  Wheel_Base: 1.60 # Wheelbase = distance between front and rear axle [m]

  Track: 1.10  # Track = distance between the contact points of the 2 front wheels [m]

  Height: 1.70  # Height of the vehicle [m]

  X_Cog: 1.10  # X coordinate of the vehicle center of gravity, in the vehicle coordinate system [m]

  Y_Cog: -0.05  # Y coordinate of the vehicle center of gravity, in the vehicle coordinate system [m]

  Z_Cog: 0.40  # Z coordinate of the vehicle center of gravity, in the vehicle coordinate system [m]

  Stiff_Front: 100000  # Front suspensions stiffness [N/m]

  Stiff_Rear: 100000 # Rear suspension stiffness [N/m]

  Damp_Front: 1000  # Front suspensions damping coefficient [N.s/m]

  Damp_Rear: 1000  # Rear suspension damping coefficient [N.s/m]

Usable from GUI.