最近想试试ros2，将系统升级成了ubuntu20.04，引发了一大堆新版本的第三方库与旧项目的冲突，果然升级还是要慎重。ros版本也升级为noetic，gozebo也相应地由9.0升级为了11.0，包括gazebo相关的第三方库也随之升级。重新使用uuv_simulator进行仿真时无法工作。重新到github下载源码重新编译。在此简要记录一下遇到的问题。

 一、gazebo11与sdformat-9.2问题

 sdformat版本升级后，编译器的版本支持也需要做出相应改动。大致会出现如下报错：

/usr/include/sdformat-9.2/sdf/Param.hh:72:57: error: expected constructor, destructor, or type conversion before ‘;’ token template<class T> ParamStreamer(T) -> ParamStreamer<T>; /usr/include/sdformat-9.2/sdf/Param.hh:83:47: error: ‘variant’ is not a member of ‘std’ ParamStreamer<std::variant<Ts...>> sv)

  根据error的log定位到uuv_gazebo_plugins的package，在其目录下的CMakeLists.txt中添加对c++17的支持：

   set(CMAKE_CXX_STANDARD 17)
   set(CMAKE_CXX_STANDARD_REQUIRED ON)

二、gazebo11与Ignition Math库问题

         Ignition Math库相应升级到了v6版本，库内一些类的命名也有所变动，导致编译时出现错误。在此给出v4版本和v6版本的API链接：

         V4：https://ignitionrobotics.org/api/math/4.0/namespaceignition_1_1math.html

         V6：https://ignitionrobotics.org/api/math/6.7/namespaceignition_1_1math.html

         还是在uuv_gazebo_plugins的package中，HydrodynamicModel.cc中计算bounding box调用的类发生了改动，原代码为ignition::math::Box ，新版本更名为 ignition::math::AxisAlignedBox，而新版本的ignition::math::Box是新的实现。需要在BuoyantObject.hh，BuoyantObject.cc，HydrodynamicModel.cc中做出相应修正。

        1、对于BuoyantObject.hh：

public: void SetBoundingBox(const ignition::math::Box &_bBox);
 
...
 
protected: ignition::math::Box boundingBox;

修改为：

public: void SetBoundingBox(const ignition::math::AxisAlignedBox &_bBox);
 
...
 
protected: ignition::math::AxisAlignedBox boundingBox;

 2、 对于BuoyantObject.cc：

void BuoyantObject::SetBoundingBox(const ignition::math::Box &_bBox)
{
  this->boundingBox = ignition::math::Box(_bBox);
 
  gzmsg << "New bounding box for " << this->link->GetName() << "::"
    << this->boundingBox << std::endl;
}

    修改为：

void BuoyantObject::SetBoundingBox(const ignition::math::AxisAlignedBox &_bBox)
{
  this->boundingBox = ignition::math::AxisAlignedBox(_bBox);
 
  gzmsg << "New bounding box for " << this->link->GetName() << "::"
    << this->boundingBox << std::endl;
}

   3、对于HydrodynamicModel.cc：

// FIXME(mam0box) This is a work around the problem of the invalid bounding
// box returned by Gazebo
  if (_sdf->HasElement("box"))
  {
    sdf::ElementPtr sdfModel = _sdf->GetElement("box");
    if (sdfModel->HasElement("width") && sdfModel->HasElement("length") &&
        sdfModel->HasElement("height"))
    {
      double width = sdfModel->Get<double>("width");
      double length = sdfModel->Get<double>("length");
      double height = sdfModel->Get<double>("height");
      ignition::math::Box boundingBox = ignition::math::Box(
        ignition::math::Vector3d(-width / 2, -length / 2, -height / 2),
        ignition::math::Vector3d(width / 2, length / 2, height / 2));
      // Setting the the bounding box from the given dimensions
      this->SetBoundingBox(boundingBox);
    }
  }

修改为：

// FIXME(mam0box) This is a work around the problem of the invalid bounding
// box returned by Gazebo
  if (_sdf->HasElement("box"))
  {
    sdf::ElementPtr sdfModel = _sdf->GetElement("box");
    if (sdfModel->HasElement("width") && sdfModel->HasElement("length") &&
        sdfModel->HasElement("height"))
    {
      double width = sdfModel->Get<double>("width");
      double length = sdfModel->Get<double>("length");
      double height = sdfModel->Get<double>("height");
      ignition::math::AxisAlignedBox boundingBox = ignition::math::AxisAlignedBox(
        ignition::math::Vector3d(-width / 2, -length / 2, -height / 2),
        ignition::math::Vector3d(width / 2, length / 2, height / 2));
      // Setting the the bounding box from the given dimensions
      this->SetBoundingBox(boundingBox);
    }
  }

 至此，编译顺利通过，仿真运行也没有问题。