Structure

The structure of the Disk Brake system can be displayed by expanding the folder in the MotionView Project browser:


Figure 1. Brake Disk System in MotionView

Datasets

Table 1. Brakes System Information Dataset
Parameter Type Range Comments
Pedal Ratio Real Value > 0 Refer to the Pedal Box schematic.
Front master cylinder piston area (mm2) Real Value > 0 PFront = KBrake boost * FFront/AreaMC_front
Rear master cylinder area (mm2) Real Value > 0 PRear = KBrake boost * FRear/AreaMC_rear
Maximum pedal force (N) Real Value > 0 Maximum pedal force exerted by the driver.
Brake demand scaling factor Real Value > 0 Brake demand corresponding to 100% braking.
Brake Boost Ratio Real Value > 0 PBrake line = KBrake boost * PMC

Variable brake boost ratio can be set using the solver variable Brake boost ratio.
Table 2. Front Disk Brakes\Datasets\Disk Brakes Info
Parameter Type Range Comments
Left Disk effective radius (mm) Real Value > 0 Refer to the Brake Disk schematic.
Right Disk effective radius (mm) Real Value > 0 Default value = Left Disk effective radius
Left piston area Real Value > 0 Left brake calliper piston area.
If:
  • No. of pistons = N.
  • Expected value = N*Area of 1 piston
Right piston area Real Value > 0 Default value = Left piston area
Left pad coefficient of friction Real Value > 0 Coefficient of friction between left brake Disk and left brake calliper pads.
Right pad coefficient of friction Real Value > 0 Default value = Right pad coefficient of friction
Stiction omega (rad/s) Real Value > 0 Angular velocity of the brake Disk above which maximum braking force is applied.

Refer to the Friction Force versus Wheel Angular Speed schematic.
Rear Disk Brakes\Datasets\Disk Brakes Info
Similar to Front Disk Brakes Info (listed above)

Solver Variables

Solver Variable Comments
Front brake line pressure Computes pressure in front brake line.

PFront = KBrake boost * FFront/AreaMC_front
Rear brake line pressure Computes pressure in front brake line.

PRear = KBrake boost * FRear/AreaMC_rear
Brake bias (forwards) User defined solver variable.

FFront = BB * FMC
Brake boost ratio User defined solver variable.

PBrake line = KBrake boost * PMC

Default brake boost ratio is a user defined constant in the Brake system info dataset.
Driver brake demand User defined solver variable. If used in an analysis (a driving analysis for example), analysis is expected to override this solver variable.

Torque

Front Disk Brakes\Forces\Brake Torque Info
Action reaction torque between knuckle and wheel hub at the wheel center.
Direction is opposite to the angular velocity of the wheel hub.
Torque magnitude is calculated according to the following equation: Friction torque on the brake Disk = Ffr * Effective RadiusBrake Disk
Rear Disk Brakes\Forces\Brake Torque Info
Similar to the Front Brake Torque Info (above)