代码注释
#include <ros/ros.h>
#include <moveit/robot_model_loader/robot_model_loader.h>
#include <moveit/robot_model/robot_model.h>
#include <moveit/robot_state/robot_state.h>
/**
* RobotModel class: 包含连杆和关节间的关系、关节限制属性、规划组
* RobotState class: 包含机器人在某个瞬时快照中的信息，储存关节位置的vector以及可选择的关节速度和加速度，
* 可用于获取机器人的运动学信息，该运动学信息取决于机器人的当前状态，例如末端效应器的雅可比矩阵
*/
int main(int argc, char **argv){
ros::init(argc, argv, "robot_model_and_robot_state_tutorial");
ros::AsyncSpinner spinner(1);
spinner.start();
/* 实例化一个RobotModelLoader对象，该对象能够在ROS参数服务器上查找机器人描述文件和构建一个RobotModel供用户使用 */
robot_model_loader::RobotModelLoader robot_model_loader("robot_description");
robot_model::RobotModelPtr kinematic_model = robot_model_loader.getModel();
ROS_INFO("Model frame: %s", kinematic_model->getModelFrame().c_str());
/* 使用RobotModel构建一个RobotState，RobotState维护了机器人的配置。我们将要设置所有的关节为默认值。
然后创建JointModelGroup，能够表示特定规划组的机器人模型，例如panda机器人的panda_arm */
robot_state::RobotStatePtr kinematic_state(new robot_state::RobotState(kinematic_model));
kinematic_state->setToDefaultValues();
const robot_state::JointModelGroup* joint_model_group = kinematic_model->getJointModelGroup("panda_arm");
const std::vector<std::string>& joint_names = joint_model_group->getVariableNames();
/* 获得关节值 */
std::vector<double> joint_values;
kinematic_state->copyJointGroupPositions(joint_model_group, joint_values);
for(std::size_t i = 0; i < joint_names.size(); ++i){
ROS_INFO("Joint %s: %f", joint_names[i].c_str(), joint_values[i]);
}
joint_values[0] = 5.57;
kinematic_state->setJointGroupPositions(joint_model_group, joint_values);
ROS_INFO_STREAM("Current state is " << (kinematic_state->satisfiesBounds() ? "valid" : "not valid"));
kinematic_state->enforceBounds();
ROS_INFO_STREAM("Current state is " << (kinematic_state->satisfiesBounds() ? "valid" : "not valid"));
/* 正运动学 */
kinematic_state->setToRandomPositions(joint_model_group);
const Eigen::Affine3d& end_effector_state = kinematic_state->getGlobalLinkTransform("panda_link8");
ROS_INFO_STREAM("Translation: \n" << end_effector_state.translation() << "\n");
ROS_INFO_STREAM("Rotation: \n" << end_effector_state.rotation() << "\n");
/* 逆运动学 */
std::size_t attempts = 10;
double timeout = 0.1;
bool found_ik = kinematic_state->setFromIK(joint_model_group, end_effector_state, attempts, timeout);
if(found_ik){
kinematic_state->copyJointGroupPositions(joint_model_group, joint_values);
for(std::size_t i = 0; i < joint_names.size(); ++i){
ROS_INFO("Joint %s: %f", joint_names[i].c_str(), joint_values[i]);
}
}else{
ROS_INFO("Did not find IK solution");
}
/* 对于给定的规划组，参照给定连杆上的特定点计算雅可比行列式 */
Eigen::Vector3d reference_point_position(0.0, 0.0, 0.0);
Eigen::MatrixXd jacobian;
kinematic_state->getJacobian(joint_model_group,
kinematic_state->getLinkModel(joint_model_group->getLinkModelNames().back()),
reference_point_position, jacobian);
ROS_INFO_STREAM("Jacobian: \n" << jacobian << "\n");
ros::shutdown();
return 0;
}
运行结果
[ INFO] [1613378520.695315909]: Loading robot model 'panda'...
[ INFO] [1613378520.805682066]: Loading robot model 'panda'...
[ INFO] [1613378520.819762498]: Model frame: /world
[ INFO] [1613378520.819980696]: Joint panda_joint1: 0.000000
[ INFO] [1613378520.820021362]: Joint panda_joint2: 0.000000
[ INFO] [1613378520.820032424]: Joint panda_joint3: 0.000000
[ INFO] [1613378520.820040063]: Joint panda_joint4: -1.570800
[ INFO] [1613378520.820065712]: Joint panda_joint5: 0.000000
[ INFO] [1613378520.820102894]: Joint panda_joint6: 0.000000
[ INFO] [1613378520.820140727]: Joint panda_joint7: 0.000000
[ INFO] [1613378520.820224733]: Current state is not valid
[ INFO] [1613378520.820281047]: Current state is valid
[ INFO] [1613378520.820444452]: Translation:
0.410832
0.324039
0.968244
[ INFO] [1613378520.820607828]: Rotation:
-0.117757 -0.280658 0.952557
-0.861389 -0.448415 -0.238606
0.494107 -0.84862 -0.188951
[ INFO] [1613378520.821023450]: Joint panda_joint1: -2.594111
[ INFO] [1613378520.821070674]: Joint panda_joint2: -0.665205
[ INFO] [1613378520.821081967]: Joint panda_joint3: -1.195657
[ INFO] [1613378520.821103151]: Joint panda_joint4: -0.311509
[ INFO] [1613378520.821124815]: Joint panda_joint5: -2.776861
[ INFO] [1613378520.821156191]: Joint panda_joint6: 1.560667
[ INFO] [1613378520.821166102]: Joint panda_joint7: 1.632811
[ INFO] [1613378520.821374549]: Jacobian:
-0.324039 -0.542396 -0.0508554 0.352593 0.0108034 -0.0530715 -1.04083e-17
0.410832 -0.330669 -0.0115386 -0.334732 0.0897549 0.0745977 -3.46945e-17
0 0.519459 0.0387756 -0.137787 -0.0588788 0.103979 -6.93889e-18
0 0.520538 0.527006 0.434347 0.277752 -0.100137 0.952557
0 -0.853838 0.321287 0.693921 0.503329 -0.831943 -0.238606
1 4.89664e-12 0.786791 -0.574296 0.818238 0.545751 -0.188951