where M is the mass of vehicle, [F.sub.N] is the friction force of vehicle, [F.sub.[omega]] is the resistance of the vehicle wheel, f is the air friction, T is the breaking torque, J is the rotational inertia of vehicle, R is the radius of vehicle, [omega] is the angular velocity of vehicle, [mu] is the attachment coefficient, and N is the normal force between the vehicle and the ground.
The attachment coefficient possesses a close relationship with the slip rate of vehicle, which can be defined as follows :
The attachment coefficient and slip rate of vehicle present a nonlinear relationship.
Figure 2 shows the relationship curve of the attachment coefficient and slip rate of vehicle.
The classification is based on electron-neutron interactions--that is, collision cross sections, drift and diffusion parameters, ionization and attachment coefficients
, and attachment reactions and rates.