The following output variables can be displayed in OptimumDynamics result and report files. The definitions of each of these are also provided and can be seen within the software when viewing result files only. Depending on the type of simulation and vehicle setup are used some of these variables are not accessible.
| Output Variables | Definition |
|---|---|
| Acceleration Input [Lateral] | The applied lateral acceleration in the simulation |
| Acceleration Input [Longitudinal] | The applied longitudinal acceleration in the simulation |
| Acceleration Input [Vertical] | The applied vertical acceleration in the simulation |
| Aerodynamic Downforce | The total aerodynamic downforce generated by the vehicle. A negative value means that the vehicle generates lift. |
| Aerodynamic Downforce [Axle] | The aerodynamic downforce reacted by the axle. A negative value means that the vehicle generates lift. |
| Aerodynamic Downforce Coefficient | The aerodynamic downforce coefficient. A positive number results in downforce. |
| Aerodynamic Downforce Distribution | This value represents the percentage of the downforce that is reacted by the front axle. |
| Aerodynamic Downforce Utilizatiom | The ratio between the current and the maximum aerodynamic downforce coefficient. |
| Aerodynamic Dragforce | The total aerodynamic dragforce generated by the vehicle. A positive value represents a force in the direction opposite to the vehicle velocity. |
| Aerodynamic Dragforce Coefficient | The aerodynamic drag coefficient. A positive value results in a dragforce. |
| Aerodynamic Efficiency | The ratio of aerodynamic downforce / aerodynamic dragforce |
| Aerodynamic Pitch Moment | The pitch moment due to the aerodynamic forces (includes downforce and drag effects) |
| Air Density The density of air | |
| All Wheels On Ground | This channel is set '1' when all wheels are in contact with the ground and '0' when at least one wheel has no normal load on it. |
| Anti-Effect [Axle] | This describes the effect of kinematic linkages in the system. An anti-effect of 100% indicates that the slope of the side view instant center passes through the vehicle center of mass and there will be minimal spring deflection. An anti-effect of 0% indicates that the side view instant center is on the ground plane and there will be minimal geometric support of the vehicle body |
| ARB Displacement [Axle] | The difference in linear displacement between the left and right side of the anti-roll bar |
| ARB Force [Axle] | The force at the tip of the ARB arm |
| ARB Linear Stiffness [Axle] | The current linear stiffness of the anti-roll bar |
| ARB Motion Ratio [Corner] | This is equal to the ratio of wheel displacement over ARB linear displacement. |
| ARB Wheel Rate [Corner] | Instantaneous wheel rate of ARB |
| Axle Normal Load [Axle] | The sum of the axle's tire vertical load |
| Axle Rotational Speed | The rotational speed of the driven axle |
| Banking Angle [Input] | The angle between the ground and the gravitational acceleration, measured from the longitudinal axis. |
| Brake Torque Distribution | The braking torque distribution. For example, a value of 70% would indicate that 70% of the braking force comes from the front wheels and 30% comes from the rear wheels. Note that this value may not be the same as the brake pressure distribution. |
| Braking Ratio [Input] | The ratio that describes how much brake is being requested |
| Bump Stop Displacement [Corner, Axle] | The distance that the Bump Stop has been compressed from its free length. A positive value represents Bump Stop compression. |
| Bump Stop Force [Corner, Axle] | The force generated due to Bump Stop displacement. |
| Bump Stop Free Length [Corner, Axle] | The length of the Bump Stop under no load. |
| Bump Stop Gap [Corner, Axle] | The current distance the coilover must compress before the bump stop is engaged. If this value is negative the bump stop is compressed. |
| Bump Stop Gap Full-Droop [Corner, Axle] | The static bump stop gap of the coilover as measured at full droop. |
| Bump Stop is Engaged | Returns 1 if Bump Stop is being compressed |
| Bump Stop Preload Displacement [Corner, Axle] | The displacement of the bump stop due to preload |
| Bump Stop Preload Force [Corner, Axle] | The force due to the bump stop preload. |
| Bump Stop Stiffness [Corner, Axle] | The instantaneous stiffness of the Bump Stop |
| Camber Angle [Corner] | The camber angle of the tire. A negative value means the top of the tire leans towards the center of the vehicle. |
| Camber Gain Heave [Corner] | The camber gain in heave for the corner. A negative value represents an increase in negative camber. |
| Center Element Motion Ratio [Corner] | This is the ratio of wheel displacement over center element displacement. |
| Chassis Heave Displacement | The vertical displacement of the center of gravity from its position when the suspension is in full droop. |
| Chassis Pitch Angle | The pitch angle of the chassis. It includes the suspension and tire displacement. |
| Chassis Roll Angle | The roll angle of the chassis. It includes the suspension and tire displacement. |
| Chassis Slip Angle (Beta) [YMD Output] | The chassis slip angle |
| Chassis Static Roll Angle | The roll angle of the chassis when the vehicle is at static position. It includes the suspension and tire displacement. |
| CoilOver Displacement [Corner, Axle] | The total axial displacement of the coilover from its free length. This does not include the effect of the installation mount displacement. A positive value represents a compression. |
| CoilOver Force [Corner, Axle] | The force generated due to coilover displacement. This includes the effect of the bump stop and spring |
| CoilOver Length [Corner, Axle] | This is the coilover eye-to-eye length. |
| CoilOver Motion Ratio [Corner] | This is the ratio of wheel displacement over coilover displacement |
| CoilOver Preload Force [Corner, Axle] | The total static preload force acting on the CoilOver. It is the combined preload force due to the spring, bump stop and damper gas. This force has to overcome for the CoilOver to displace. |
| Coilover Stiffness [Corner, Axle] | The effective stiffness of the coilover as a whole. |
| Contact Patch Location (X,Y,Z) [Corner] | The position of the tire contact patch from the vehicles center of gravity. |
| Differential Input Torque | Torque delivered to the differential after gearing |
| Elastic Force [Corner] | This is the elastic portion of the total vertical force that acts between the vehicle body and the unsprung body. It is due to the deflection of the elastic elements that connect the vehicle body and the corner unsprung bodies. |
| Elastic Force Ratio [Corner] | This is the ratio of the elastic force over the total vertical force that acts between the vehicle body and the unsprung body |
| Engaged Gear [Input] | The current engaged gear of the gearbox |
| Engine Output Torque | The torque of the engine |
| Engine Rotational Speed | The rotational speed of the engine axle |
| Front View Instant Center Location (X,Y,Z) [Corner] | The point where the instant axis (between the wheel and the chassis) crosses the lateral axle plane |
| Frontal Area | The frontal area of the vehicle used in the calculations for the aerodynamic model |
| Geometric Force [Corner] | This is the geometric portion of the total vertical force that acts between the vehicle body and the unsprung body. It is due to the direct kinematic connection between the vehicle body and the corner unsprung bodies. Geometric Force does not cause deflection of the elastic elements that connect vehicle body and the corner unsprung bodies. |
| Geometric Force Ratio [Corner] | This is the ratio of the geometric force over the total vertical force that acts between the vehicle body and the unsprung body. |
| Grade Angle [Input] | The angle between the ground and the gravitational acceleration, measured from the lateral axis. |
| Input Parameters Aerodynamics Downforce Scaling Factor | This is the input value for the aerodynamic downforce scaling factor |
| Input Parameters Aerodynamics Drag Scaling Factor | This is the input value for the aerodynamics downforce |
| Input Parameters Aerodynamics Frontal Area | This is the input value for the aerodynamics frontal area |
| Input Parameters Brakes Brake Distribution Front | This is the input value for the front brake distribution |
| Input Parameters Chassis CG Height | This is the input value for the chassis center of gravity height |
| Input Parameters Chassis Axle Ride Height | This is the input value for the ride height at the axle |
| Input Parameters Chassis Mass Distribution Front | This is the input value for the front chassis mass distribution |
| Input Parameters Chassis Non-Suspended Mass Corner | This is the input value for the non-suspended mass for the corner |
| Input Parameters Chassis Reference Axle Ride Height | This is the input value for the reference chassis ride height when the CG height was measured |
| Input Parameters Chassis Total Mass | This is the input value for the total chassis mass |
| Input Parameters Axle Suspension ARB Stiffness | This is the input value for the anti-roll bar stiffness for the axle |
| Input Parameters Axle Suspension Corner Coilover Bumpstop Gap | This is the input value for the coilover bumpstop gap for the corner |
| Input Parameters Axle Suspension Corner Coilover Spring Gap | This is the input value for the coilover spring gap for the corner |
| Input Parameters Axle Suspension Corner Coilover Spring Stiffness | This is the input value for the coilover spring stiffness for the corner |
| Input Parameters Axle Suspension Corner Half Track | This is the input value for the half track of the corner |
| Input Parameters Axle Suspension Corner Static Camber | This is the input value for the static camber for the corner |
| Input Parameters Axle Suspension Corner Static Toe | This is the input value for the static toe for the corner |
| Input Parameters Axle Suspension Corner Tire Pressure | This is the input value for the tire pressure for the corner |
| Input Parameters Front Suspension Steering Rack Pinion Rack Ratio | This is the input value for the steering rack ratio |
| Input Parameters Reference Distance | This is the input value for the reference distance |
| Instantaneous Roll Gradient | Amount of Body Roll per Lateral Acceleration |
| Lateral Load Transfer Distribution | The ratio of front lateral load transfer to the total lateral load transfer due to all external inputs. If negligible or no load transfer is occurring, the solver will return NaN. |
| Lateral Velocity | Lateral Velocity of the Chassis in Chassis x-y coordinates |
| Load Distribution [Cross] | The sum of the front left and rear right tire normal load divided by the total tire normal load |
| Load Distribution [Axle] | The sum of the front left and front right tire normal load divided by the total tire normal load |
| Load Distribution [Left] | The sum of the front left and rear left tire normal load divided by the total tire normal load |
| Longitudinal Velocity | Longitudinal Velocity of the Chassis in Chassis x-y coordinates |
| Mechanical Trail [Corner] | Distance between intersection of the steeering axis and the center of the contact patch |
| Non-Suspended Mass [Corner] | The static non-suspended mass of the corner |
| Resultant Lateral Acceleration | The resultant achieved lateral acceleration of the vehicle |
| Resultant Longitudinal Acceleration | The resultant achieved longitudinal acceleration of the vehicle |
| Resultant Vertical Acceleration | The resultant achieved vertical acceleration of the vehicle |
| Resultant Turn Radius | The resultant achieved turn radius of the vehicle |
| Resultant Wheel Torque [Corner] | The torque at the wheel center generated by the tire longitudinal force |
| Ride Height [Axle] | The vertical displacement of the vehicle as measured at the front/rear track |
| Roll Angle [Axle] | The roll angle of the vehicle chassis about the longitudinal axis. This is the sum of the tire and suspension roll angle |
| Scrub Radius [Corner] | Scrub Radius |
| Roll Center Height [Axle] | The geometric roll center height at the front/ rear plane of the vehicle |
| Side View Instant Center Location X [Corner] | The point where the instant axis (between the wheel and the chassis) crosses the longitudinal axle plane |
| Side View Instant Center Location Y [Corner] | The point where the instant axis (between the wheel and the chassis) crosses the longitudinal axle plane |
| Side View Instant Center Location Z [Corner] | The point where the instant axis (between the wheel and the chassis) crosses the longitudinal axle plane |
| Simulation [Distance] | The total distance the vehicle has travelled during the simulation |
| Simulation [Percentage Completion] | The percentage of the simulation completion |
| Simulation [Time] | This is the time in the simulation completion |
| Simulation Input [Steering] | This is the applied steering wheel angle for the simulation |
| Simulation Input [Velocity] | The input velocity for the simulation |
| Slip Angle [Corner] | This is the slip angle of the corner |
| Slip Angle for Peak Fy [Corner] | This is the slip angle of the tire that corresponds to the greatest lateral force for the given normal load, camber angle, slip ratio, speed, and pressure. |
| Slip Ratio [Corner] | This is the slip ratio of the corner |
| Solver Converged | A value of '1' means a successful solution for the vehicle was found based on the given simulation inputs. A value of '0' means a valid solution for the vehicle was not possible. |
| Solver Convergence Error | The sum of convergence errors |
| Solver Convergence Error – Heave | The heave convergence error |
| Solver Convergence Error – Pitch | The pitch convergence error |
| Solver Convergence Error – Roll | The roll convergence error |
| Solver Convergence Error [Corner] | The corner convergence error |
| Solver Time To Solve (Iteration) | The time taken to solve the particular iteration |
| Solver Total Iterations | The total number of iterations required to reach a solution |
| Spool Rotational Speed | The rotational speed of the driven axle |
| Spring Displacement [Corner, Axle] | The distance that the Spring has been compressed from its free length. A positive value represents Spring compression |
| Spring Force [Corner, Axle] | The force generated due to spring displacement |
| Spring Free Length [Corner, Axle] | The length of the Spring under no load |
| Spring Gap [Corner, Axle] | The current distance the coilover must compress before the spring is engaged. If this value is negative the spring is compressed |
| Spring Gap Full-Droop [Corner, Axle] | The static spring gap of the coilover as measured at full droop |
| Spring Preload Displacement [Corner, Axle] | The displacement of the spring due to static preload |
| Spring Preload Force [Corner, Axle] | The force due to the spring preload |
| Spring Stiffness [Corner, Axle] | The instantaneous stiffness of the Spring |
| Spring Wheel Rate [Corner] | Instantaneous Spring Wheel Rate |
| Static Camber Angle [Corner] | The static camber angle of the corner as measured on a setup pad |
| Static Corner Force [Corner] | The static corner force |
| Static Ride Height [Axle] | The ride height in the static vehicle position |
| Static Roll Center Height [Axle] | The roll center height in the static vehicle position |
| Static Suspended CG Location (X,Y,Z) | The static position of the vehicle suspended center of gravity |
| Static Toe Angle [Corner] | The toe angle of the tire in the static vehicle position |
| Static Total Non-Suspended Mass CG Location (X,Y,Z) | The position of the total non-suspended mass center of gravity from the total vehicle center of gravity in the static vehicle position |
| Static Track Width [Axle] | The lateral distance between the tire contact patches in the static vehicle position |
| Static Weight Distribution [Cross] | The sum of the front left and rear right weight divided by the total weight |
| Static Weight Distribution [Axle] | The sum of the front left and front right weight divided by the total weight |
| Static Weight Distribution [Left] | The sum of the front left and rear left weight divided by the total weight |
| Static Wheelbase [Left] | The longitudinal distance between the tire contact patches in the static vehicle position |
| Static Wheelbase Average | The average wheelbase of the vehicle in the static position |
| Steered Angle [Axle] | This is the steering angle before the rack |
| Suspended CG Location (X,Y,Z) | The suspended mass center of gravity |
| Suspended Mass | The suspended mass of the vehicle |
| Suspension Displacement [Corner] | Relative displacement between the wheel and the chassis |
| Suspension Pitch Angle [Axle] | The pitch angle due to the suspension movement only. This does not include the pitch angle due to the tire deflection. |
| Suspension Roll Angle [Axle] | The roll angle due to suspension movement only. This does not include the roll angle due to tire deflection. |
| Tire Deflection [Corner] | The vertical displacement between the contact patch and wheel center |
| Tire Force (X,Y,Z) [Corner] | The X components of the force generated at the tire contact patch |
| Tire Heave | The contribution to the total vehicle heave displacement that is due to tire deflection |
| Tire Inflation Pressure [Front Left] | The inflation pressure of the tire |
| Tire Lateral Force Percentage [Front Left] | The lateral force percentage use of the tire, defined as (MaxFy-CurrentFy)/MaxFy. A number greater than 100% means the tire is overused, while a number under 100% means the tire is underused. |
| Tire Lateral Friction Coefficient [Corner] | The lateral coefficient of friction of the tire |
| Tire Loaded Radius [Corner] | The vertical distance from wheel center to ground |
| Tire Longitudinal Force Percentage [Corner] | The longitudinal force percentage use of the tire, defined as (MaxFx-CurrentFx)/MaxFx. A number greater than 100% means the tire is overused, while a number under 100% means the tire is underused. |
| Tire Longitudinal Friction Coefficient [Corner] | The longitudinal coefficient of friction of the tire |
| Tire Moment Z [Front Left] | The Z component of the moment generated at the tire contact patch. Also known as Aligning Torque |
| Tire Overall Friction Coefficient [Front Left] | The overall coefficient of friction of the tire |
| Tire Pitch Angle [Left] | The contribution to the total vehicle pitch angle that is due to tire deflection only |
| Tire Roll Angle [Front] | The contribution to the total vehicle roll angle that is due to tire deflection only |
| Tire Unloaded Radius [Front Left] | This is the unloaded radius of the tire |
| Tire Vertical Displacement [Front Left] | This is the vertical displacement of the tire. A positive value represents a compression and vice versa. |
| Tire Vertical Stiffness [Front Right] | This is the vertical stiffness of the tire |
| Tire Wheel Rate [Front Left] | Instantaneous Tire Wheel Rate |
| Toe Angle [Front Right] | The toe angle of the corner. A positive value indicates toe out. |
| Total Mass | The total mass of the vehicle |
| Total Non-Suspended Mass CG Location (X,Y,Z) | The position of the total non-suspended mass center of gravity from the total vehicle center of gravity. |
| Total Tire Fz | The total sum of the tire vertical Fz force components |
| Total Wheel Rate [Front Left] | Instantaneous wheel rate of suspension and tire spring in series (not inclusive of third springs or anti roll bars) |
| Track Map (X,Y) Coordinate | The location of the vehicle CG in the global fixed coordinate system |
| Track Width [Front] | The lateral distance between the tire contact patches |
| Vehicle Center of Mass Location (X,Y,Z) | The vehicle center of mass position from the total vehicle center of gravity |
| Vehicle Control | Change in Yaw Moment with Respect To Steering |
| Vehicle Stability | Change in Yaw Moment with Respect To Chassis Slip |
| Vehicle Throttle Stability | Change in Yaw Moment with Respect To Applied Throttle |
| Wheel Center Location (X,Y,Z) [Front Left] | The position of the wheel center from the total vehicle center of gravity |
| Wheelbase [Left] | The distance between the front and rear tire contact patch in the longitudinal direction. |
| Wheelbase Average | The average of the left and right wheelbase |
| Yaw Moment [Output] | Yaw Moment acting on Vehicle CG |
| Yaw Rate (r) [YMD Output] | Yaw Rate |
| Yaw Rate Error | The yaw rate calculation convergence error |