TABLE 1.

RL agent’s observation vector at each time step t (Meyer et al., 2020a). The FeasibilityPooling algorithm calculates the maximum reachable distance in a given sector for the rangefinder suite. Obstacle velocities are relative to the body frame rotated such that the longitudinal axis is parallel to the centerline of the given sector and describe the velocity of the closest obstacle in that sector. Static obstacles assume a relative velocity of zero.

	Feature	Definition
Navigation	Surge velocity	u (t)
	Sway velocity	v (t)
	Yaw rate	r (t)
	Cross-track error	ϵ(t)     (Eq. 1)
	Heading error	${\tilde{\psi }}^{(t)}$    (Eq. 2)
	Look-ahead heading error	${\tilde{\psi }}_{LA}^{(t)}$    (Eq. 3)
Perception	Obstacle closeness, first sector	$1-\frac{1}{S_r}\text{FeasibilityPooling}(\mathbf{x}=\{x_1,\dots ,x_d\})$
	⋮
	Obstacle closeness, last sector	$1-\frac{1}{S_r}\text{FeasibilityPooling}(\mathbf{x}=\{x_{N-d},\dots ,x_N\})$
	Obstacle velocity, first sector	[v x,1, v y,1]
	⋮
	Obstacle velocity, last sector	[v x,N, v y,N]