What are the SIX Degrees of Freedom?

Six degrees of freedom is the total number of ways an object can move in three-dimensional space, with three rotational motions, and three translational or linear motions.   All six degrees of freedom are centered around three axes comprised of two horizontal axes, and one vertical axis. (commonly referred to by X, Y, and Z) All three axes intersect in a mutually perpindicular fashion, at the center of mass (or center of gravity), of the body in motion. All six degrees of freedom are required to meet the industry standard definition of “Full Motion”.

Three Degrees of Rotation – Angularly moving about the three axes

ROLL – Rotating about the longitudinal horizontal axis is ROLLING.
PITCH – Rotating about the lateral horizontal axis is PITCHING.
YAW – Rotating about the vertical axis is YAWING.

Three Degrees of Translation – Linearly moving along the three axes

SURGE – Moving forwards and backwards along the longitudinal horizontal axis is called SURGING.
SWAY – Moving left and right along the lateral horizontal axis is called SWAYING.
HEAVE – Moving up and down along the vertical axis is called HEAVING.

Rotational Motions of Roll, Pitch and Yaw

ROLL – Rotation about the horizontal longitudinal axis that runs from the front to the rear, through the center of mass.   Roll motion in racing simulation applications is utilized for simulating body roll or left/right weight transfer, and unsustained lateral “G-Force” sensations in response to steering wheel input.

Roll motion is also utilized for the simulation of track and terrain orientation such as banking, track camber, and curbing.

PITCH – Rotation about the horizontal lateral axis that runs from the left to the right, through the center of mass.   Pitch motion in racing simulation applications is utilized for simulating front/rear weight transfer and unsustained longitudinal “G-Force” sensations associated with forward and rearward accelerations, in response to throttle and brake pedal input.

Pitch motion is also utilized for the simulation of track and terrain orientation such as uphills, downhills, track surface imperfections such as cracks and bumps, and curbing.

YAW – Rotation about the vertical axis that runs up and down, through the center of mass.   Yaw motion in racing simulation applications is utilized for simulating oversteer (loss of rear traction) and understeer (loss of front traction) of the car, in response to steering wheel, throttle and brake pedal inputs.

Yaw is sometimes misunderstood as a heading or facing direction.   In racing simulator applications with motion, the yaw angle (the difference between the direction the car is facing and the direction the car is traveling) is commonly used for positioning

Translational Motions of Surge, Sway, and Heave

SURGE – Linear or translational motion along the longitudinal axis that runs from the front to the back, through the center of mass.   Motions on the surge degree of freedom are associated with forward and rearward accelerations and decelerations, typically associated with throttle and brake pedal inputs, but can be influenced by environmental conditions such as curbing and tire barriers.

SWAY – Linear or translational motion along the lateral axis that runs from the left to the right, through the center of mass.   Motions on the sway degree of freedom are associated with left and right accelerations and decelerations, typically associated with steering wheel inputs, but can be influenced by environmental conditions such as soft or loose surfaces.  

HEAVE – Linear or translational motion along the vertical axis that runs up and down, through the center of mass.   Motions on the heave degree of freedom are associated with up and down accelerations and decelerations, typically associated with environmental conditions such as incline/decline transitions, track surface imperfections such as cracks and bumps, and curbing.