FastBike3D_7.3â

SOFTWARE FOR DYNAMIC ANALYSIS OF TWO WHEELED VEHICLES

The motorcycle model consists of six bodies:
·the front and rear wheels,
·    the rear assembly,
·    the front assembly,
·    the rear swinging arm,
·    the unsprung front mass.
The vehicle has eleven degrees of freedom corresponding to the coordinates of the chassis center of mass, the pitch, roll, yaw and steering angles, the travel of front and rear suspensions and the wheel spin rotations.
The motorcycle has four inputs:
·      the steering torque,
·the front brake torque,
·      the rear brake torque,
·      the engine torque.

The tire model is specific for motorcycle. The model takes into account the geometry and deformability of the carcass, properly works at very large camber angle, both in stationary and transient conditions.

The interaction of the tire with the road can is represented by three forces and three moments. These quantities are given in terms of forward velocity, camber angle, longitudinal and lateral slips and load acting on the tire itself.

The chain power transmission is modeled in detail. The inclination angle of the chain and the swinging arm influences the motorcycle's trim. The trim depends also on the stiffness characteristics of the front and rear wheel suspension, and on the forces operating on the motorcycle. 

The front suspension is a telescopic type and the rear suspension is a swinging arm type.

Shock absorbers were modeled using a non-linear relation between force and suspension travel rate.

The shape of the tire carcass is modeled as a revolute surface, and the road is modeled as a generic non-regular surface with few restrictions on its local curvature.

SIMULATIONS

STC : Static Trim Calculation
SSA : Steady State Analysis
FMS : Free-Motorcycle Stability
FMSC : Free-Motorcycle Stability with Compliance
FRF : Frequency Response functions
CSLC

SLCM

: Control Synthesis for Lane Change

: Simulation of Lane Change Maneuver

CSS

SSM

: Control Synthesis for Slalom

: Simulation of Slalom Maneuver

CSC

SCM

: Control Synthesis for Cornering

: Simulation of Cornering Maneuver

BFR : Braking on a Flat Road
AFR : Acceleration on a Flat Road
PBP : Passing on a Bump or a Pothole
RRA : Running on a Rough Asphalt