Struct Params 

pub struct Params {
    pub tau: f64,
    pub a_ped: f64,
    pub b_ped: f64,
    pub a_wall: f64,
    pub b_wall: f64,
    pub mass: f64,
    pub max_speed: f64,
    pub arrival_radius: f64,
    pub max_accel: f64,
}

Parameters for the Social Force model.

Defaults are taken from Helbing, Farkas & Vicsek (2000) Table 1.

Fields

tau: f64

Relaxation time toward the desired velocity (s).

a_ped: f64

Interaction strength between pedestrians (N).

b_ped: f64

Interaction range between pedestrians (m).

a_wall: f64

Interaction strength with walls (N).

b_wall: f64

Interaction range with walls (m).

mass: f64

Pedestrian mass (kg).

max_speed: f64

Hard upper bound on speed after integration (m/s).

arrival_radius: f64

Arrival radius (m). Inside this distance the desired speed tapers linearly to zero so the agent decelerates into its destination instead of overshooting and oscillating. Set to 0.0 to disable the taper. Default: 0.3 m.

max_accel: f64

Hard upper bound on acceleration magnitude (m/s²).

The Helbing exponential repulsion is numerically stiff: at a light body overlap of 0.1 m the pair force with default a_ped = 2000 N and b_ped = 0.08 m is already ~5.4 kN, i.e. ~68 m/s² for an 80 kg pedestrian. Explicit integration at dt = 0.05 s would push the velocity by 3.4 m/s in a single tick, relying entirely on max_speed to keep the trajectory physical. Clamping |a| ≤ max_accel before integration gives a well-behaved CFL-like bound: the default of 20 m/s² (≈ 2 g) is enough headroom for crowded panic flows but low enough that dt * max_accel ≤ max_speed at typical simulation rates. JuPedSim and PedSim apply the same cap; this is a standard production hardening for SFM.

Implementations

impl Params

pub fn validate(&self, dt: f64) -> Result<(), CrowdError>

Validate this parameter set against dt.

Returns Ok(()) if every invariant holds, otherwise the first offending constraint as a [CrowdError]. Guards the same failure modes as the other force-based models: non-positive physical parameters, non-negative arrival radius, finite positive dt, and the explicit-Euler CFL-like condition dt * max_accel <= max_speed.

Cheap: a handful of comparisons, no allocations.

Trait Implementations

impl Clone for Params

fn clone(&self) -> Params

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Params

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Params

fn default() -> Self

Returns the “default value” for a type.

impl PartialEq for Params

fn eq(&self, other: &Params) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for Params

impl StructuralPartialEq for Params