Example #1
0
def solid_cont_dyn(X, F_b, M_b, P):
    Xd = np.zeros(sv_size)
    p_w, v_w, q_w2b, om_b = X[sv_slice_pos], X[sv_slice_vel], X[sv_slice_quat], X[sv_slice_rvel]
    # Translational kinematics
    Xd[sv_slice_pos] = v_w
    # Newton for forces
    R_w2b =  pal.rmat_of_quat(q_w2b)
    Xd[sv_slice_vel] = 1./P.m*(np.dot(R_w2b.T, F_b) + [0, 0, P.m*P.g])
    # Rotational kinematics
    Xd[sv_slice_quat] = pal.quat_derivative(q_w2b, om_b)
    # Newton for moments
    Xd[sv_slice_rvel] = np.dot(P.invJ, M_b - np.cross(om_b, np.dot(P.J, om_b)))
    return Xd
Example #2
0
 def cont_dyn(self, X, t, U):
     Fb, Mb = U[:3], U[3:]
     Xd = np.zeros(self.sv_size)
     p_w, v_w, q_w2b, om_b = X[self.sv_slice_pos], X[self.sv_slice_vel], X[self.sv_slice_quat], X[self.sv_slice_rvel]
     # Translational kinematics
     Xd[self.sv_slice_pos] = v_w
     # Newton for forces
     R_w2b =  pal.rmat_of_quat(q_w2b)
     Xd[self.sv_slice_vel] = 1./self.P.m*(np.dot(R_w2b.T, Fb) + [0, 0, self.P.m*self.P.g])
     #Xd[self.sv_slice_vel] = 1./self.P.m*(np.dot(R_w2b.T, Fb))
     # Rotational kinematics
     Xd[self.sv_slice_quat] = pal.quat_derivative(q_w2b, om_b)
     # Newton for moments
     Xd[self.sv_slice_rvel] = np.dot(self.P.invJ, Mb - np.cross(om_b, np.dot(self.P.J, om_b)))
     return Xd
Example #3
0
File: frames.py Project: poine/pat
 def cont_dyn(cls, X, t, U, P, add_weight=False):
     Fb, Mb = U[:3], U[3:]
     Xd = np.zeros(cls.sv_size)
     p_w, ivel_b, q_w2b, rvel_b = X[cls.sv_slice_pos], X[
         cls.sv_slice_vel], X[cls.sv_slice_quat], X[cls.sv_slice_rvel]
     R_b2w = p3_alg.rmat_of_quat(q_w2b).T
     # Translational kinematics
     Xd[cls.sv_slice_pos] = vel_body_to_world_R(ivel_b, R_b2w)
     # Newton for forces
     Xd[cls.sv_slice_vel] = 1 / P.m * Fb - 2. * np.cross(rvel_b, ivel_b)
     # do we add weight or not???
     #if add_weight: Xd[cls.sv_slice_vel] += 1./P.m*(np.array([0, 0, P.m*P.g]))
     # Rotational kinematics
     Xd[cls.sv_slice_quat] = p3_alg.quat_derivative(q_w2b, rvel_b)
     # Newton for moments
     Xd[cls.sv_slice_rvel] = np.dot(
         P.invI, Mb - np.cross(rvel_b, np.dot(P.I, rvel_b)))
     return Xd
Example #4
0
File: frames.py Project: poine/pat
 def cont_dyn(cls, X, t, U, P, add_weight=False):
     Fb, Mb = U[:3], U[3:]
     Xd = np.zeros(cls.sv_size)
     p_w, v_w, q_w2b, om_b = X[cls.sv_slice_pos], X[cls.sv_slice_vel], X[
         cls.sv_slice_quat], X[cls.sv_slice_rvel]
     # Translational kinematics
     Xd[cls.sv_slice_pos] = v_w
     # Newton for forces
     R_b2w = p3_alg.rmat_of_quat(q_w2b).T
     Xd[cls.sv_slice_vel] = 1. / P.m * (np.dot(R_b2w, Fb))
     # do we add weight or not???
     if add_weight:
         Xd[cls.sv_slice_vel] += 1. / P.m * (np.array([0, 0, P.m * P.g]))
     # Rotational kinematics
     Xd[cls.sv_slice_quat] = p3_alg.quat_derivative(q_w2b, om_b)
     # Newton for moments
     Xd[cls.sv_slice_rvel] = np.dot(P.invI,
                                    Mb - np.cross(om_b, np.dot(P.I, om_b)))
     return Xd
Example #5
0
    def state_and_cmd_of_flat_output(self, Y, P):
        #pdb.set_trace()
        wind = np.zeros(3)
        cd_ov_m = P.Cd / P.m  #param[prm_Cd]/param[prm_mass]
        a0 = np.array([
            Y[_x, 2] + cd_ov_m * (Y[_x, 1] - wind[_x]),
            Y[_y, 2] + cd_ov_m * (Y[_y, 1] - wind[_y]),
            Y[_z, 2] + cd_ov_m * (Y[_z, 1] - wind[_z]) - 9.81
        ])
        a1 = np.array([
            Y[_x, 3] + cd_ov_m * Y[_x, 2], Y[_y, 3] + cd_ov_m * Y[_y, 2],
            Y[_z, 3] + cd_ov_m * Y[_z, 2]
        ])
        a2 = np.array([
            Y[_x, 4] + cd_ov_m * Y[_x, 3], Y[_y, 4] + cd_ov_m * Y[_y, 3],
            Y[_z, 4] + cd_ov_m * Y[_z, 3]
        ])
        psi = Y[_psi, 0]
        cpsi, spsi = np.cos(psi), np.sin(psi)
        psi1 = Y[_psi, 1]
        psi2 = Y[_psi, 2]
        b0 = np.array([
            cpsi * a0[_x] + spsi * a0[_y], -spsi * a0[_x] + cpsi * a0[_y],
            a0[_z]
        ])
        b1 = np.array([
            cpsi * a1[_x] + spsi * a1[_y] - psi1 *
            (spsi * a0[_x] - cpsi * a0[_y]), -spsi * a1[_x] + cpsi * a1[_y] -
            psi1 * (cpsi * a0[_x] + spsi * a0[_y]), a1[_z]
        ])
        b2 = np.array([
            cpsi * a2[_x] + spsi * a2[_y] - 2 * psi1 *
            (spsi * a1[_x] - cpsi * a1[_y]) +
            (-psi2 * spsi - psi1**2 * cpsi) * a0[_x] +
            (psi2 * cpsi - psi1**2 * spsi) * a0[_y], -spsi * a2[_x] +
            cpsi * a2[_y] - 2 * psi1 * (cpsi * a1[_x] + spsi * a1[_y]) +
            (-psi2 * cpsi + psi1**2 * spsi) * a0[_x] +
            (-psi2 * spsi - psi1**2 * cpsi) * a0[_y], a2[_z]
        ])

        c0 = math.sqrt(b0[_x]**2 + b0[_z]**2)
        c1 = (b0[_x] * b1[_x] + b0[_z] * b1[_z]) / c0
        c2 = (b1[_x]**2 + b0[_x] * b2[_x] + b1[_z]**2 + b0[_z] * b2[_z] -
              c1**2) / c0
        n2a = a0[_x]**2 + a0[_y]**2 + a0[_z]**2
        na = math.sqrt(n2a)

        # euler
        phi0 = -np.sign(b0[_z]) * math.atan(b0[_y] / c0)
        theta0 = math.atan(b0[_x] / b0[_z])
        # euler dot
        phi1 = (b1[_y] * c0 - b0[_y] * c1) / n2a  # checked
        theta1 = (b1[_x] * b0[_z] - b0[_x] * b1[_z]) / c0**2  # checked
        # rvel
        cph = math.cos(phi0)
        sph = math.sin(phi0)
        cth = math.cos(theta0)
        sth = math.sin(theta0)
        p = phi1 - sth * psi1
        q = cph * theta1 + sph * cth * psi1
        r = -sph * theta1 + cph * cth * psi1
        # euler dot dot
        phi2   = (b2[_y]*c0 - b0[_y]*c2)/na**2 \
                 -2*(b1[_y]*c0-b0[_y]*c1)*(b0[_x]*b1[_x]+b0[_y]*b1[_y]+b0[_z]*b1[_z])/na**4 # checked
        theta2 = (b2[_x]*b0[_z] - b0[_x]*b2[_z])/c0**2 \
                 -2*(b1[_x]*b0[_z] - b0[_x]*b1[_z])*(b0[_x]*b1[_x]+b0[_z]*b1[_z])/c0**4 # checked
        # raccel
        p1 = phi2 - cth * theta1 * psi1 - sth * psi2
        q1 = -sph * phi1 * theta1 + cph * theta2 + cph * cth * phi1 * psi1 - sph * sth * theta1 * psi1 + sph * cth * psi2
        r1 = -cph * phi1 * theta1 - sph * theta2 - sph * cth * phi1 * psi1 - cph * sth * theta1 * psi1 + cph * cth * psi2

        _q = pal.quat_of_euler([phi0, theta0, psi])
        X = np.array([
            Y[_x, 0], Y[_y, 0], Y[_z, 0], Y[_x, 1], Y[_y, 1], Y[_z, 1], _q[0],
            _q[1], _q[2], _q[3], p, q, r
        ])
        Ut = na * P.m
        Jxx, Jyy, Jzz = np.diag(P.J)
        #Up = Jxx/P.l * p1 + (Jzz-Jyy)/P.l*q*r
        #Uq = Jyy/P.l * q1 + (Jxx-Jzz)/P.l*p*r
        #Ur = Jzz/P.k * r1 + (Jyy-Jxx)/P.k*p*q

        Up = Jxx * p1 + (Jzz - Jyy) * q * r
        Uq = Jyy * q1 + (Jxx - Jzz) * p * r
        Ur = Jzz * r1 + (Jyy - Jxx) * p * q

        U = np.array([Ut, Up, Uq, Ur])

        qdot = pal.quat_derivative(_q, [p, q, r])
        Xd = np.array([
            Y[_x, 1], Y[_y, 1], Y[_z, 1], Y[_x, 2], Y[_y, 2], Y[_z, 2],
            qdot[pal.q_i], qdot[pal.q_x], qdot[pal.q_y], qdot[pal.q_z], p1, q1,
            r1
        ])

        return X, U, Xd