diff --git a/补课/多体动力学/四元数/bonus_gimbal_lock.pdf b/补课/多体动力学/四元数/bonus_gimbal_lock.pdf
new file mode 100644
index 0000000..9d757af
Binary files /dev/null and b/补课/多体动力学/四元数/bonus_gimbal_lock.pdf differ
diff --git a/补课/多体动力学/四元数/quaternion.pdf b/补课/多体动力学/四元数/quaternion.pdf
new file mode 100644
index 0000000..5d3196e
Binary files /dev/null and b/补课/多体动力学/四元数/quaternion.pdf differ