BicycleParameters Data File Information

bicycles/<bicycle name>/Parameters/<bicycle name>Benchmark.txt

<bicycle name>Benchmark.txt contains the complete parameter set needed to analyze the Whipple bicycle model linearized about the upright configuration. Each line should have one of the 24 benchmark parameters in the following format:

c = 0.080+/-0.001

The first characters are a unique variable name, followed by an equal sign, the value of the parameter, a plus or minus symbol (+/-), and the standard deviation of the value. There can be spaces between the parts. Use 0.0 for the standard deviation if this is unknown or if you are not concerned with the uncertainties. Use the same units as the benchmark bicycle paper. These are the possible variables:

  • g : acceleration due to gravity [m/s**2]
  • c : trail [m]
  • w : wheelbase [m]
  • lam : steer axis tilt [rad]
  • rR : rear wheel radius [m]
  • rF : front wheel radius [m]
  • mB : frame/rider mass [kg]
  • mF : front wheel mass [kg]
  • mH : handlebar/fork assembly mass [kg]
  • mR : rear wheel mass [kg]
  • xB : x distance to the frame/rider center of mass [m]
  • zB : z distance to the frame/rider center of mass [m]
  • xH : x distance to the frame/rider center of mass [m]
  • zH : z distance to the frame/rider center of mass [m]
  • IBxx : x moment of inertia of the frame/rider [kg*m**2]
  • IBzz : z moment of inertia of the frame/rider [kg*m**2]
  • IBxz : xz product of inertia of the frame/rider [kg*m**2]
  • IFxx : x moment of inertia of the front wheel [kg*m**2]
  • IFyy : y moment of inertia of the front wheel [kg*m**2]
  • IHxx : x moment of inertia of the handlebar/fork [kg*m**2]
  • IHzz : z moment of inertia of the handlebar/fork [kg*m**2]
  • IHxz : xz product of inertia of the handlebar/fork [kg*m**2]
  • IRxx : x moment of inertia of the rear wheel [kg*m**2]
  • IRyy : y moment of inertia of the rear wheel [kg*m**2]

Optional Parameters

These parameters are assumed to equal zero if not given.

  • yB : y distance to the frame/rider center of mass [m]
  • yH : y distance to the handlebar/fork center of mass [m]
  • IBxy : xy product of inertia of the frame/rider [kg*m**2]
  • IByy : y moment of inertia of the frame/rider [kg*m**2]
  • IByz : yz product of inertia of the frame/rider [kg*m**2]
  • IHxy : xy product of inertia of the handlebar/fork [kg*m**2]
  • IHyy : y moment of inertia of the handlebar/fork [kg*m**2]
  • IHyz : yz product of inertia of the handlebar/fork [kg*m**2]

bicycles/<bicycle name>/RawData/<bicycle name>Measured.txt

This documentation does not contain the complete details of acquiring the raw data. Please refer to [Moore2010] and our website for more information.

<bicycle name>Measured.txt contains the raw measurement data for a bicycle. The file should have one variable on each line in the following format:

mR = 1.38+/-0.02, 1.37+/-0.02

This is the same as the previous parameter variable definition accept that multiple measurements can be included as comma separated values. The values will be averaged together on import. The following gives the measured values:

  • aB1 : perpendicular distance from the pendulum axis to the rear axle center, first orienation [m]
  • aB2 : perpendicular distance from the pendulum axis to the rear axle center, second orienation [m]
  • aB3 : perpendicular distance from the pendulum axis to the rear axle center, third orienation [m]
  • aH1 : perpendicular distance from the pendulum axis to the front axle center, first orienation [m]
  • aH2 : perpendicular distance from the pendulum axis to the front axle center, second orienation [m]
  • aH3 : perpendicular distance from the pendulum axis to the front axle center, third orienation [m]
  • alphaB1 : angle of the head tube with respect to horizontal, first orientation [deg]
  • alphaB2 : angle of the head tube with respect to horizontal, second orientation [deg]
  • alphaB3 : angle of the head tube with respect to horizontal, third orientation [deg]
  • alphaH1 : angle of the steer tube with respect to horizontal, first orientation [deg]
  • alphaH2 : angle of the steer tube with respect to horizontal, second orientation [deg]
  • alphaH3 : angle of the steer tube with respect to horizontal, third orientation [deg]
  • dF : distance the front wheel travels [m]
  • dP : diameter of the calibration rod [m]
  • dR : distance the rear wheel travels [m]
  • f : fork offset [m]
  • g : acceleration due to gravity [m/s**2]
  • gamma : head tube angle [deg]
  • lF : front wheel compound pendulum length [m]
  • lP : calibration rod length [m]
  • lR : rear wheel compound pendulum length [m]
  • mB : frame mass [kg]
  • mF : front wheel mass [kg]
  • mH : fork/handlebar mass [kg]
  • mP : calibration rod mass [kg]
  • mR : rear wheel mass [kg]
  • nF : number of rotations of the front wheel
  • nR : number of rotations of the rear wheel
  • TcB1 : frame compound pendulum oscillation period [s]
  • TcF1 : front wheel compound pendulum oscillation period [s]
  • TcH1 : fork/handlebar compound pendulum oscillation period [s]
  • TcR1 : rear wheel compound pendulum oscillation period [s]
  • TtB1 : frame torsional pendulum oscillation period, first orientation [s]
  • TtB2 : frame torsional pendulum oscillation period, second orientation [s]
  • TtB3 : frame torsional pendulum oscillation period, third orientation [s]
  • TtF1 : front wheel torsional pendulum oscillation period, first orientation [s]
  • TtH1 : handlebar/fork torsional pendulum oscillation period, first orientation [s]
  • TtH2 : handlebar/fork torsional pendulum oscillation period, second orientation [s]
  • TtH3 : handlebar/fork torsional pendulum oscillation period, third orientation [s]
  • TtP1 : calibration torsional pendulum oscillation period [s]
  • TtR1 : rear wheel torsional pendulum oscillation period [s]
  • w : wheelbase [m]

Geometry Option

The default option is to provide the wheelbase w, fork offset f, head tube angle gamma and the wheel radii rR rF, but there is a secondary option for the geometric variables using the perpendicular distances from the steer axis to the wheel centers and the distance between their respective intersection points. To use these, simply replace w, gamma, and f with these dimensions:

  • h1 : distance from the base of the height gage to the top of the rear wheel axis [m]
  • h2 : distance from the table surface to the base of the height gage [m]
  • h3 : distance from the table surface to the top of the head tube [m]
  • h4 : height of the top of the front wheel axle [m]
  • h5 : height of the top of the steer tube [m]
  • d1 : outer diameter of the head tube [m]
  • d2 : diameter of the dummy rear axle [m]
  • d3 : diameter of of the dummy front axle [m]
  • d4 : outer diameter of the steer tube [m]
  • d : inside distance between the rear and the front axles with the fork reversed [m]

The details of how to take these measurements can be found in our raw data sheet and on our webpage.

Rider Configuration Details

A rider can be situated on the bicycle if other raw bicycle measurements are provided.

  • lsp : the length of the seat post (i.e. the length from the intersection of the top tube with the seat tube to the top of the seat along the axis of the seat tube. [m]
  • lst : the length of the seat tube (i.e. the distance from the center of the bottom bracket to the intersection of the seat tube and the top tube) [m]
  • hbb : the height of the bottom bracket off the ground [m]
  • lamst : the acute angle between horizontal and the seat tube [rad]
  • lcs : the distance from the center of the bottom bracket to the center of the rear wheel [m]
  • LhbR : the distance from the center of the rear wheel to either the left or right the handlebar grip (roughly where the center of the hand would fall) [m]
  • LhbF : the distance from the center of the front wheel to either the left or right the handlebar grip (roughly where the center of the hand would fall) [m]

Other

You may see these values, xcl and zcl, in the Rigid and Rigidcl bicycles input files. They locate the lateral force point in the benchmark coordinates. Also, ds1 and ds3 locate the accelerometer with respect to a point on the steer axis which is aligned with the handlebar center of mass.

Fork/Handlebar Separation

The measurement of the fork and the handlebar as two rigid bodies is also supported. See the example bicycle called Rigid for more details. The fork subscript is S and the handlebar subscript is G.

Notes

  • The periods T are not required if you provide oscillation signal data files.
  • You have to specify at least three orientations but more can increase the accuracy of the parameter estimations. Currently you can specify up to six orientation for each rigid body.

Pendulum Data Files

If you have raw signal data that the periods can be estimated from, then these should be included in the RawData directory. There should be at least one file for every period typically found in <bicycle name>Measured.txt file. The signals collected should exhibit very typical decayed oscillations. Currently the only supported file is a Matlab mat file with these variables:

  • data : signal vector of a decaying oscillation
  • sampleRate : sample rate of data in hertz

The files should be named in this manner <short name><part><pendulum><orientation><trial>.mat where:

  • <bicycle name> is the short name of the bicycle
  • <part> is either Fork, Handlebar, Frame, Rwheel, or Fwheel
  • <orientation> is either First, Second, Third, Fourth, Fifth, or Sixth
  • <trial> is an integer greater than or equal to 1

Notes

  • Fork is the handlebar/fork assembly if they are measured as one rigid body (subscript is H). Otherwise Fork (S) is the fork and Handlebar (G) is the handlebar when they are measured separately.

riders/<rider name>/Parameters/

<rider name><bicycle name>Benchmark.txt

This file contains the inertial parameters for a rigid rider configured to sit on a particular bicycle expressed with reference to the benchmark reference frame and the rider’s center of mass. You can provide these values or let the program generate them.

  • mB : rider mass [kg]
  • xB : x distance to the rider center of mass [m]
  • yB : y distance to the rider center of mass [m]
  • zB : z distance to the rider center of mass [m]
  • IBxx : x moment of inertia of the rider [kg*m**2]
  • IByy : y moment of inertia of the rider [kg*m**2]
  • IBzz : z moment of inertia of the rider [kg*m**2]
  • IBxy : xy product of inertia of the rider [kg*m**2]
  • IBxz : xz product of inertia of the rider [kg*m**2]
  • IByz : yz product of inertia of the rider [kg*m**2]

yB, IBxy, and IByz are optional due to the assumed symmetry of the rider.

Combined/<rider name><bicycle name>Benchmark.txt

This file contains the geometric and inertial benchmark parameters for a rider seated on a bicycle. The rider is assumed to be rigidly attached to the bicycle frame. These parameters are the same as the ones stored in bicycles/Parameters/<bicycle name>Benchmark.txt. These file are only output files.

riders/<rider name>/RawData/

These files must follow the YAML format used in the `yeadon package`_.

<rider name><bicycle name>YeadonCFG.txt

This is an input file to set the configuration of the joint angles for the yeadon package. All values should be set to zero except the sommersault value. The sommersault value is pi minus the hunch angle of the rider on the bicycle. The hunch angle is the angle between the horizontal and the rider’s torso mid line. It is essentially the angle at which the rider is leaned forward.

<rider name><bicycle name>YeadonCFG.txt

This is the yeadon measurement input file for the yeadon package. It contains all of the geometric measurements of the rider. See the yeadon documentation for more details.