Obbart/universal_robots_ros_driver
1
0
Fork 0
mirror of https://gitlab.com/obbart/universal_robots_ros_driver.git synced 2026-04-10 01:50:46 +02:00
Code Releases Activity

Cleaned up legacy code and updated documentation.

Browse Source
This commit is contained in:
Felix Mauch
2019-05-29 08:52:39 +02:00
parent a603e9bb97
commit 6adda40a3f
2 changed files with 49 additions and 75 deletions
Download Patch File Download Diff File Expand all files Collapse all files

65
ur_calibration/include/ur_calibration/calibration.h
View File

@@ -101,26 +101,6 @@ struct DHRobot
}
return ret;
}
/*!
* \brief Generates a string representation of this robot representation.
*
* This string can be directly included into the xacro file used for a calibrated robot.
*/
std::string toXacroProperties()
{
std::stringstream ss;
for (size_t i = 0; i < segments_.size(); ++i)
{
ss << "<xacro:property name=\"d" << i + 1 << "\" value=\"" << segments_[i].d_ << "\" />\n";
ss << "<xacro:property name=\"a" << i + 1 << "\" value=\"" << segments_[i].a_ << "\" />\n";
ss << "<xacro:property name=\"theta" << i + 1 << "\" value=\"" << segments_[i].theta_ << "\" />\n";
ss << "<xacro:property name=\"alpha" << i + 1 << "\" value=\"" << segments_[i].alpha_ << "\" />\n";
}
ss << "<xacro:property name=\"delta_theta_correction2\" value=\"" << delta_theta_correction2_ << "\" />\n";
ss << "<xacro:property name=\"delta_theta_correction3\" value=\"" << delta_theta_correction3_ << "\" />\n";
return ss.str();
}
};
/*!
@@ -145,28 +125,59 @@ public:
*/
void correctChain();
/*!
* \brief Get the transformation matrix representation of the chain as constructed by the
* DH parameters.
*
* This will contain twice as many transformation matrices as joints, as for each set of DH
* parameters two matrices are generated. If you'd like to receive one matrix per joint instead,
* use the getSimplified() function instead.
*
* \returns A vector of 4x4 transformation matrices, two for each joint going from the base to the
* tcp.
*/
std::vector<Eigen::Matrix4d> getChain()
{
return chain_;
}
std::string toXacroProperties()
{
return robot_parameters_corrected_.toXacroProperties();
}
YAML::Node toYaml() const;
/*!
* \brief Get the transformation matrix representation of the chain, where each joint is
* represented by one matrix.
*
* \returns Vector of 4x4 transformation matrices, one for each joint going from the base to the
* tcp.
*/
std::vector<Eigen::Matrix4d> getSimplified() const;
/*!
* \brief Generates a yaml representation of all transformation matrices as returned by
* getSimplified()
*
* \returns A YAML tree representing all tranformation matrices.
*/
YAML::Node toYaml() const;
/*!
* \brief Calculates the forwart kinematics given a joint configuration with respect to the base
* link.
*
* \param joint_values Joint values for which the forward kinematics should be calculated.
* \param link_nr If given, the cartesian position for this joint (starting at 1) is returned. By
* default the 6th joint is used.
*
* \returns Transformation matrix giving the full pose of the requested link in base coordinates.
*/
Eigen::Matrix4d calcForwardKinematics(const Eigen::Matrix<double, 6, 1>& joint_values, const size_t link_nr = 6);
private:
// Corrects a single axis
void correctAxis(const size_t correction_index);
// Builds the chain from robot_parameters_
void buildChain();
DHRobot robot_parameters_;
DHRobot robot_parameters_corrected_;
std::vector<std::string> link_names_ = { "shoulder", "upper_arm", "forearm", "wrist_1", "wrist_2", "wrist_3" };
std::vector<Eigen::Matrix4d> chain_;

59
ur_calibration/src/calibration.cpp
View File

@@ -27,9 +27,6 @@ Calibration::~Calibration()
void Calibration::correctChain()
{
robot_parameters_corrected_ = robot_parameters_;
robot_parameters_corrected_.delta_theta_correction2_ = 0.0;
robot_parameters_corrected_.delta_theta_correction3_ = 0.0;
correctAxis(1);
correctAxis(2);
}
@@ -57,31 +54,24 @@ void Calibration::correctAxis(const size_t link_index)
return;
}
Eigen::Matrix<double, 6, 1> jointvalues;
jointvalues << 0, 0, 0, 0, 0, 0;
// Eigen::Matrix4d fk_current = calcForwardKinematics(jointvalues, link_index);
// Eigen::Vector3d current_passive = fk_current.topRightCorner(3, 1);
// ROS_INFO_STREAM("current passive:\n" << current_passive);
Eigen::Matrix4d fk_current = Eigen::Matrix4d::Identity();
Eigen::Vector3d current_passive = Eigen::Vector3d::Zero();
Eigen::Matrix4d fk_next_passive = Eigen::Matrix4d::Identity();
fk_next_passive *= chain_[link_index * 2] * chain_[link_index * 2 + 1];
Eigen::Vector3d eigen_passive = fk_next_passive.topRightCorner(3, 1);
// ROS_INFO_STREAM("Eigen passive:\n" << eigen_passive);
Eigen::Vector3d eigen_next = (fk_next_passive * chain_[(link_index + 1) * 2]).topRightCorner(3, 1);
// ROS_INFO_STREAM("Eigen next:\n" << eigen_next);
// Construct a representation of the next segment's rotational axis
Eigen::ParametrizedLine<double, 3> next_line;
next_line = Eigen::ParametrizedLine<double, 3>::Through(eigen_passive, eigen_next);
// ROS_INFO_STREAM("next_line:" << std::endl
//<< "Base:" << std::endl
//<< next_line.origin() << std::endl
//<< "Direction:" << std::endl
//<< next_line.direction());
ROS_DEBUG_STREAM("next_line:" << std::endl
<< "Base:" << std::endl
<< next_line.origin() << std::endl
<< "Direction:" << std::endl
<< next_line.direction());
// XY-Plane of first segment's start
Eigen::Hyperplane<double, 3> plane(fk_current.topLeftCorner(3, 3) * Eigen::Vector3d(0, 0, 1), current_passive);
@@ -95,10 +85,10 @@ void Calibration::correctAxis(const size_t link_index)
double new_theta = std::atan(intersection.y() / intersection.x());
// Upper and lower arm segments on URs all have negative length due to dh params
double new_length = -1 * intersection.norm();
// ROS_INFO_STREAM("Wrist line intersecting at " << std::endl << intersection);
// ROS_INFO_STREAM("Angle is " << new_theta);
// ROS_INFO_STREAM("Length is " << new_length);
// ROS_INFO_STREAM("Intersection param is " << intersection_param);
ROS_DEBUG_STREAM("Wrist line intersecting at " << std::endl << intersection);
ROS_DEBUG_STREAM("Angle is " << new_theta);
ROS_DEBUG_STREAM("Length is " << new_length);
ROS_DEBUG_STREAM("Intersection param is " << intersection_param);
// as we move the passive segment towards the first segment, we have to move away the next segment
// again, to keep the same kinematic structure.
@@ -107,46 +97,24 @@ void Calibration::correctAxis(const size_t link_index)
// Set d parameter of the first segment to 0 and theta to the calculated new angle
// Correct arm segment length and angle
// ROS_INFO_STREAM("Passive old:\n" << chain_[2 * link_index]);
chain_[2 * link_index](2, 3) = 0.0;
robot_parameters_corrected_.segments_[link_index].d_ = 0.0;
chain_[2 * link_index].topLeftCorner(3, 3) =
Eigen::AngleAxisd(new_theta, Eigen::Vector3d::UnitZ()).toRotationMatrix();
robot_parameters_corrected_.segments_[link_index].theta_ = new_theta;
// ROS_INFO_STREAM("Passive new:\n" << chain_[2 * link_index]);
// Correct arm segment length and angle
// ROS_INFO_STREAM("Next old:\n" << chain_[2 * link_index + 1]);
// ROS_INFO_STREAM("Theta correction: " << robot_parameters_.segments_[link_index].theta_ - new_theta);
// ROS_INFO_STREAM("Alpha correction: " << robot_parameters_.segments_[link_index].alpha_);
chain_[2 * link_index + 1](0, 3) = new_length;
robot_parameters_corrected_.segments_[link_index].a_ = new_length;
chain_[2 * link_index + 1].topLeftCorner(3, 3) =
Eigen::AngleAxisd(robot_parameters_.segments_[link_index].theta_ - new_theta, Eigen::Vector3d::UnitZ())
.toRotationMatrix() *
Eigen::AngleAxisd(robot_parameters_.segments_[link_index].alpha_, Eigen::Vector3d::UnitX()).toRotationMatrix();
if (link_index == 1)
{
robot_parameters_corrected_.delta_theta_correction2_ = robot_parameters_.segments_[link_index].theta_ - new_theta;
}
else if (link_index == 2)
{
robot_parameters_corrected_.delta_theta_correction3_ = robot_parameters_.segments_[link_index].theta_ - new_theta;
}
// ROS_INFO_STREAM("Next new:\n" << chain_[2 * link_index + 1]);
// Correct next joint
// ROS_INFO_STREAM("Second Next old:\n" << chain_[2 * link_index + 2]);
chain_[2 * link_index + 2](2, 3) -= distance_correction;
robot_parameters_corrected_.segments_[link_index + 1].d_ -= distance_correction;
// ROS_INFO_STREAM("Second Next new:\n" << chain_[2 * link_index + 2]);
}
Eigen::Matrix4d Calibration::calcForwardKinematics(const Eigen::Matrix<double, 6, 1>& joint_values,
const size_t link_nr)
{
// ROS_INFO_STREAM("Calculating forward kinematics at link " << link_nr);
// Currently ignore input and calculate for zero vector input
Eigen::Matrix4d output = Eigen::Matrix4d::Identity();
@@ -158,8 +126,6 @@ Eigen::Matrix4d Calibration::calcForwardKinematics(const Eigen::Matrix<double, 6
output *= simplified_chain[i] * rotation;
}
// ROS_INFO_STREAM("forward_kinematics at " << link_nr << std::endl << output);
return output;
}
@@ -193,16 +159,13 @@ std::vector<Eigen::Matrix4d> Calibration::getSimplified() const
simplified_chain.push_back(chain_[i] * chain_[i + 1]);
Eigen::Matrix3d rot_a = chain_[i].topLeftCorner(3, 3);
Eigen::Vector3d rpy_a = rot_a.eulerAngles(0, 1, 2);
// ROS_INFO_STREAM("Rotation " << i / 2 << " a: [" << rpy_a.transpose() << "]");
Eigen::Matrix3d rot_b = chain_[i + 1].topLeftCorner(3, 3);
Eigen::Vector3d rpy_b = rot_b.eulerAngles(0, 1, 2);
// ROS_INFO_STREAM("Rotation " << i / 2 << " b: [" << rpy_b.transpose() << "]");
// ROS_INFO_STREAM("Matrix " << i / 2 << ":\n" << simplified_chain.back());
Eigen::Matrix3d rot = simplified_chain.back().topLeftCorner(3, 3);
Eigen::Vector3d rpy = rot.eulerAngles(0, 1, 2);
Eigen::Quaterniond quat(rot);
// ROS_INFO_STREAM("Rotation (rpy) " << i / 2 << ": [" << rpy.transpose() << "]");
// ROS_INFO_STREAM("Rotation (quat, [xyz], w)" << i / 2 << ": [" << quat.vec().transpose() << "], " << quat.w());
}
simplified_chain.push_back(chain_.back());
return simplified_chain;