Config File Format

The structure of the config file is as follows:

• Tibia Definition
• Femur Definition
• Frame Refs Points

The structure of Tibia and Femur definitions are as follows:

• Collar Definition
• Origin Definition
• Link Definition
• Sensor Definition
• Optional Info
• External Info

To read the tibia details, the config file MUST be in this order. Specification for each section are given below.

• First word is "collar" followed by the number: 1.
• Collar 1 definition (see Section col for specifics on collar definition.
• The words "collar 2" followed by collar 2 definition.

• Collar Definitions
• The collar definition is provided as follows in the file:
  • After the word "collar" & collar number (1 or 2), a list of LINK labels that define the collar are provided. This list is space separated. The list ends with the word "end".
  • The word "left" is written to indicate succession of LINKs in the collar in left direction. After the word, the list of LINK labels is given and the list must end with the word "end"
  • The word "right" is written to indicate succession of LINKs in the collar in right direction. After the word, the list of LINK labels is given and the list must end with the word "end".

• Origin Defintion
• The word "origin" followed by definition of origin as follows:
  • LINK label on which origin is located
  • The x,y,z co-ordinates of the location in the LINK frame

• The word "links" followed by each LINK defintion. For specifics on LINK definition see section LINK below.
• The link section ends after the definition of the last link.
• The total number of link definitions must be equal to the number of links specified in the collar definitions. If there is an unequal number, it will result in an error.

• Link Definitions
• The LINK definition is as follows:
  • The first word is the link label. This must correspond exactly to one link label specified in the collar definitions.
  • The next lines contains the 3 co-ordinates of the 4 reference points on the plate in the link frame, written in the following order
    • left top
    • right top
    • left bottom
    • right bottom
  • The left hinge axis
  • The right hinge axis
  • The word "end" if angle data is not known.
  • Otherwise, the word "angle", followed by link label, followed by adjecent link label with respect to which angle data is known.
  • The two angles that determine the interval angle between two links. (ie, if calibrated to some value, both angles are identical. if known to lie in a range, the two angles specify the range).
  • If second angle is known, the word "angle" followed by data in above format.
  • The word "end" to signal the end of current link defintion

• Sensor definitions.
• The words "sensors" is written to indicate the beginning of sensor definitions, and ends with "end_sensors".
• The order in which the sensors are defined is:
  • Passive wires
  • Active wires
  • Accelerometers
  • Optical markers
  • Force sensors
  • Free sensors

• Passive wires:
  • The word "passive_wire" followed by wire id (an integer)
  • The link label on which it is attached
  • The 3 coordinates of the point on link to which wire is attached.
  • The word "stiffness" followed by up to 10 parameters to characterise wire stiffness polynomial. The word "end" must be written to signify end of passive sensor definition

• Active wires:
  • The word "active_wire" followed by wire id (an integer)
  • The link label on which it is attached
  • The 3 coordinates of the point on link to which wire is attached.
  • The word "stiffness" followed by up to 10 parameters to characterise wire stiffness polynomial. The word "end" must be written to signify end of active sensor definition

• Accelerometers:
  • The word "accelerometer" followed by accelerometer id (an integer)
  • The link label on which it is attached
  • The 3 coordinates of the accelerometer origin in the link frame
  • The 9 numbers that specify the Rotation matrix between the link frame and the accelerometer body fixed frame.
  • The word "end" to signify end of accelerometer definition

• Optical Markers:
  • The word "optical_marker" followed by marker id (an integer)
  • The link label on which it is attached
  • The 3 coordinates of the point on link frame where it is attached
  • The label of the point on which the marker is placed, as defined in the OptiTrack software ie tibia_root1 or tibia_root2 and so on.
  • The word "end" to signify end of marker definition

• Force Sensor
  • The word "force_sensor" followed by marker id (an integer)
  • The link label on which it is attached
  • The 3 coordinates of the center of the sensor in link frame
  • The 3 components specifying the axis normal to the force sensor in the link frame
  • The word "end" to signify the end of force sensor definition.

• Free Sensors
  • The word "free" followed by marker id (an integer)
  • The link label on which it is attached
  • The 3 coordinates of the sensor origin written in the link frame
  • The word "paramter" followed by up to 10 parameters to characterise the sensor. The word "end" must be written to signify end of sensor definition.

• The last word must be "end_sensors" to signify end of all sensor definitions.

• Optional Data
• The word "optional" is used to denote the start of optional info.
• This stores calibrated distances, sensor info (what it measures) for distance sensors or free sensors.

• Calibrated Distances
  • This word is "distance" followed by the word "collar" and the collar id.
  • The link label followed by the 3 co-ordinates of the point on the link.
  • The word "collar" followed by collar id, link label and coordinates for second point. The distance between these two points is the calibrated known distance.
  • This is followed by the distance and the word "end", if calibrated distance is known, or by the lower and upper limit of the range followed by "end" if the distance is only known to lie in a range.

• Sensor info (What distance is Measured)
  • The word "measured_distance" followed by sensor id which measures it.
  • The word "collar" followed by collar id.
  • Followed by link label and 3 co-ordinates of point on the link
  • The word "collar" followed by collar id, link label and coordinates for second point.
  • The word "end" to denote end of info

• Free sensor info
  • The word "free_sensor" followed by sensor id (an integer)
  • The word "collar" followed by collar id.
  • Followed by link label and 3 co-ordinates of point on the link
  • The word "collar" followed by collar id, link label and coordinates for second point.
  • The word "parameter" followed by up to 25 parameters to describe the sensor parameters
  • The wod "end" to denote end of info.

• The word "end_optional" denotes the end of optional data info

• External info
• This has info about external sensors that gives info with respect to global frame. There can be four kinds of infos.
• Distance Sensor
  • The word "external_distance_sensor" followed by sensor id.
  • The 3 coordinates of point on reference frame, followed by coordinates of point on body frame. ie the two points between the sensor measures distance.

• Free sensor:
  • The word "external_free_sensor" followed by sensor id, followed by up to 25 paramters.
  • The word "end" to denote the end of parameter definition.

• Force plate
  • The word "external_force_plate" followed by the word "left" if mounted on left shoe, or "right" if mounted on right shoe.
  • Up to 25 sensor paramters, followed by word "end" to denote end of parameter definition.

• Force pad
  • The word "external_force_pad" followed by up to 25 paramters.
  • The word "end" to denote the end of parameter definition.

• The word "end_external" to signify end of external data (and end of file)