error: 'THIS_METHOD_IS_ONLY_FOR_VECTORS_OF_A_SPECIFIC_SIZE' is not a member of 'Eigen::internal::static_assertion'|
显示有问题的地方：
crossag = acc.cross(gyro);
crossag1 = crossag.cross(acc);
前面进行了声明
VectorXd acc(3);
VectorXd gyro(3);
VectorXd crossag,
VectorXd crossag1,