论文实现:Reactive Nonholonomic Trajectory Generation via Parametric Optimal Control
1. 多项式螺旋
曲率:
κ ( s ) = a 0 + a 1 s + a 2 s 2 + a 3 s 3 + a 4 s 4 + a 5 s 5 \begin{align} \kappa(s) = a_0 + a_1s + a_2s^2 + a_3s^3 + a_4s^4 + a_5s^5 \end{align} κ(s)=a0+a1s+a2s2+a3s3+a4s4+a5s5
机器人朝向:
θ ( s ) = a 0 s + a 1 s 2 2 + a 2 s 3 3 + a 3 s 4 4 + a 4 s 5 5 + a 5 s 6 6 \begin{align} \theta(s) = a_0s + \frac{a_1s^2}{2} + \frac{a_2s^3}{3} + \frac{a_3s^4}{4} + \frac{a_4s^5}{5} + \frac{a_5s^6}{6} \end{align} θ(s)=a0s+2a1s2+3a2s3+4a3s4+5a4s5+6a5s6
轨迹:
x ( s ) = ∫ 0 s cos ( θ ( s ) ) d s \begin{align} x(s) = \int_0^s{\cos(\theta(s))ds} \end{align} x(s)=∫0scos(θ(s))ds
y ( s ) = ∫ 0 s sin ( θ ( s ) ) d s \begin{align} y(s) = \int_0^s{\sin(\theta(s))ds} \end{align} y(s)=∫0ssin(θ(s))ds
2. 边界条件
初始条件: s = 0 , x = 0 , y = 0 , θ = 0 s = 0,x = 0, y = 0, \theta = 0 s=0,x=0,y=0,θ=0
结束条件: s = s f , x = x f , y = y f , θ = θ f s = s_f, x = x_f, y = y_f, \theta = \theta_f s=sf,x=xf,y=yf,θ=θf
x b = [ x f y f θ f ] T \begin{align} \bf{x_b} = \left[ x_f \ y_f \ \theta_f \right]^T \end{align} xb=[xf yf θf]T
参数:
q = [ a 0 a 1 a 2 a 3 a 4 a 5 s f ] T \begin{align} \bf{q} = \left[a_0 \ a_1 \ a_2 \ a_3 \ a_4 \ a_5 \ s_f \right]^T \end{align} q=[a0 a1 a2 a3 a4 a5 sf]T
边界条件:
g ( q ) = h ( q ) − x b = { x ( s f ) − x f = 0 y ( s f ) − y f = 0 θ ( s f ) − θ f = 0 \begin{align} \bf{g(q)} = \bf{h(q)} - \bf{x_b} = \begin{cases} x(s_f) - x_f = 0 \\ y(s_f) - y_f = 0 \\ \theta(s_f) - \theta_f = 0 \end{cases} \end{align} g(q)=h(q)−xb=⎩ ⎨ ⎧x(sf)−xf=0y(sf)−yf=0θ(sf)−θf=0
待续…