[KDL库学习]KDL库安装与使用

我的使用安装环境是Ubuntu20，使用vscode+cmake进行编译与调试。
安装KDL库前必须安装好Eigen库。
KDL库是机械臂的运动学、动力学、轨迹规划的开源第三方库，功能强大。

一、Eigen库安装

首先可以搜索一下

sudo apt search eigen3

然后就出来了这几个选择，选择一个安装，很多其他的库安装也可以先搜索一下，这个命令还挺好用的

sudo apt install libeigen3-dev

二、KDL库安装

首先将远程代码仓的代码拷贝到本地

git clone https://github.com/orocos/orocos_kinematics_dynamics.git

然后切换到对应的目录

cd orocos_kinematics_dynamics/
cd orocos_kdl

然后创建build文件夹

mkdir build

然后编译以及安装

cd build
cmake ..
make
sudo make install

正常来说到这里KDL库就已经安装好了。

三、KDL库使用

找个新的文件夹，打开命令行，执行（目的是运行vscode打开当前文件夹）

code .

然后创建CMakeLists.txt以及main.cc两个文件
CMakeLists.txt中内容为：

cmake_minimum_required(VERSION 3.10)
project(learn_kdl)
find_package(Eigen3 REQUIRED CONFIG)
find_package(orocos_kdl REQUIRED)
add_executable(main main.cc)
target_link_libraries(main Eigen3::Eigen orocos-kdl orocos-kdl-models)

main.cc中的内容参考的KDL源码下的examples文件夹下的trajectory_example.cpp
内容如下

/*** \file path_example.cpp* An example to demonstrate the use of trajectory generation* functions.** There are is a matlab/octave file in the examples directory to visualise the results* of this example program. (visualize_trajectory.m)**/#include <frames.hpp>
#include <frames_io.hpp>
#include <trajectory.hpp>
#include <trajectory_segment.hpp>
#include <trajectory_stationary.hpp>
#include <trajectory_composite.hpp>
#include <trajectory_composite.hpp>
#include <velocityprofile_trap.hpp>
#include <path_roundedcomposite.hpp>
#include <rotational_interpolation_sa.hpp>
#include <utilities/error.h>
#include <utilities/utility.h>
#include <trajectory_composite.hpp>int main(int argc,char* argv[]) {using namespace KDL;// Create the trajectory:// use try/catch to catch any exceptions thrown.// NOTE:  exceptions will become obsolete in a future version.try {// Path_RoundedComposite defines the geometric path along// which the robot will move.//Path_RoundedComposite* path = new Path_RoundedComposite(0.2,0.01,new RotationalInterpolation_SingleAxis());// The routines are now robust against segments that are parallel.// When the routines are parallel, no rounding is needed, and no attempt is made// add constructing a rounding arc.// (It is still not possible when the segments are on top of each other)// Note that you can only rotate in a deterministic way over an angle less then PI!// With an angle == PI, you cannot predict over which side will be rotated.// With an angle > PI, the routine will rotate over 2*PI-angle.// If you need to rotate over a larger angle, you need to introduce intermediate points.// So, there is a common use case for using parallel segments.path->Add(Frame(Rotation::RPY(PI,0,0), Vector(-1,0,0)));path->Add(Frame(Rotation::RPY(PI_2,0,0), Vector(-0.5,0,0)));path->Add(Frame(Rotation::RPY(0,0,0), Vector(0,0,0)));path->Add(Frame(Rotation::RPY(0.7,0.7,0.7), Vector(1,1,1)));path->Add(Frame(Rotation::RPY(0,0.7,0), Vector(1.5,0.3,0)));path->Add(Frame(Rotation::RPY(0.7,0.7,0), Vector(1,1,0)));// always call Finish() at the end, otherwise the last segment will not be added.path->Finish();// Trajectory defines a motion of the robot along a path.// This defines a trapezoidal velocity profile.VelocityProfile* velpref = new VelocityProfile_Trap(0.5,0.1);velpref->SetProfile(0,path->PathLength());  Trajectory* traject = new Trajectory_Segment(path, velpref);Trajectory_Composite* ctraject = new Trajectory_Composite();ctraject->Add(traject);ctraject->Add(new Trajectory_Stationary(1.0,Frame(Rotation::RPY(0.7,0.7,0), Vector(1,1,0))));// use the trajectorydouble dt=0.1;std::ofstream of("./trajectory.dat");for (double t=0.0; t <= traject->Duration(); t+= dt) {Frame current_pose;current_pose = traject->Pos(t);for (int i=0;i<4;++i)for (int j=0;j<4;++j)of << current_pose(i,j) << "\t";of << "\n";// also velocities and accelerations are available !//traject->Vel(t);//traject->Acc(t);}of.close();// you can get some meta-info on the path:for (int segmentnr=0;  segmentnr < path->GetNrOfSegments(); segmentnr++) {double starts,ends;Path::IdentifierType pathtype;if (segmentnr==0) {starts = 0.0;} else {starts = path->GetLengthToEndOfSegment(segmentnr-1);}ends = path->GetLengthToEndOfSegment(segmentnr);pathtype = path->GetSegment(segmentnr)->getIdentifier();std::cout << "segment " << segmentnr << " runs from s="<<starts << " to s=" <<ends;switch(pathtype) {case Path::ID_CIRCLE:std::cout << " circle";break;case Path::ID_LINE:std::cout << " line ";break;default:std::cout << " unknown ";break;}std::cout << std::endl;}std::cout << " trajectory written to the ./trajectory.dat file " << std::endl;delete ctraject;} catch(Error& error) {std::cout <<"I encountered this error : " << error.Description() << std::endl;std::cout << "with the following type " << error.GetType() << std::endl;}
}

然后在vscode的最底下这栏，设置好编译器，我用的是clang，也可以用其他的，比如gcc，如果没有需要自行安装。

还需要在vscode中安装好c++以及cmake的扩展

好了，一切就像，可以开始编译了，点击vscode的最底下这栏的build，然后开始编译

没有问题的话就可以运行编译出来的可执行文件了，

最底下这栏，可以设置是debug模式还是release模式，点击三角形或者虫子符号，就可以运行了，最右边的main是可执行文件名称，如果有多个可执行文件，可以执行哪个。

执行结果如上所示，结束。