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    "# CompositeInertia\n",
    "\n",
    "Generally there are two algorithm to calculate robot dynamics.\n",
    "\n",
    "Featherstone’s algorithm\n",
    "Lagrangian method\n",
    "\n",
    "Fetherstone's algorithm best practice is so-called Articulated-Body Algorithm which is described in forward_dynamics_propagation.md\n",
    "\n",
    "Here we discuss a most import part in Lagrangian method. how to get composite inertia.\n",
    "\n",
    "Theory\n",
    "\n",
    "\n",
    "\n",
    "Pseudo\n",
    "\n",
    "\n",
    "Code\n",
    "H = 0\n",
    "for $i = 1$ to $N_B$\n",
    "  $I^c_i = I_i$\n",
    "end\n",
    "for i = N_B to 1\n",
    "    if $\\lambda(i) \\ne 0$\n",
    "$\\qquad I^A_{\\lambda(i)} = I^A_{\\lambda(i)} + {}^{\\lambda(i)}X^*_i I^c_i \\space {}^iX_{\\lambda(i)}$\n",
    "end\n",
    "Generally there are two algorithm to calculate robot dynamics.\n",
    "\n",
    "Featherstone’s algorithm\n",
    "Lagrangian method\n",
    "\n",
    "Fetherstone's algorithm best practice is so-called Articulated-Body Algorithm which is described in forward_dynamics_propagation.md\n",
    "\n",
    "Here we discuss a most import part in Lagrangian method. how to get composite inertia.\n",
    "\n",
    "Theory\n",
    "\n",
    "\n",
    "\n",
    "Pseudo\n",
    "\n",
    "\n",
    "Code\n",
    "H = 0\n",
    "for $i = 1$ to $N_B$\n",
    "  $I^c_i = I_i$\n",
    "end\n",
    "for i = N_B to 1\n",
    "    if $\\lambda(i) \\ne 0$\n",
    "$\\qquad I^A_{\\lambda(i)} = I^A_{\\lambda(i)} + {}^{\\lambda(i)}X^*_i I^c_i \\space {}^iX_{\\lambda(i)}$\n",
    "end"
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