通过Euler角度输入旋转四元数 [英] Rotate a quaternion by Euler angles input

问题描述

我正在编写代码来控制3D空间中的机械臂。机械臂通过四元数来处理旋转，但是我希望用户通过更改偏航角，俯仰和滚动来控制它，因为它对人类使用这些更敏感。

I am writing a code to control robotic arm in 3D space. The robotic arm handle the rotation by quaternion but I want user to control it by changing yaw, pitch and roll since its more sensible for human to use these.

我编写了函数获取用户想要在每个方向（滚动，俯仰，偏航）上旋转手臂并输出新的四元数的量。我将current_quaternion保存为全局变量。

I wrote function to get the amount that user wants to rotate the arm in each of directions(roll, pitch, yaw) and output the new quaternion. I saved the current_quaternion as a global variable.

我正在使用C ++和Eigen。

I am using C++ and Eigen.

Eigen::Quaterniond euler2Quaternion( const double roll,
              const double pitch,
              const double yaw)
{

Eigen::AngleAxisd rollAngle(roll,Eigen::Vector3d::UnitX());
Eigen::AngleAxisd pitchAngle(pitch,Eigen::Vector3d::UnitY());
Eigen::AngleAxisd yawAngle(yaw,Eigen::Vector3d::UnitZ());

Eigen::Quaterniond q = rollAngle*pitchAngle*yawAngle;
current_q=q*current_q;
return current_q;
}

我尝试了很多改变角度乘和UnitX（）的顺序的方法，

I tried many things changing the order of multiplying angles and multiplying UnitX(), UnitY() and UnitZ() by current_q.toRotationMatrix() but non of them worked.

推荐答案

您的示例几乎与示例

Matrix3f m;
m = AngleAxisf(0.25*M_PI, Vector3f::UnitX())
  * AngleAxisf(0.5*M_PI,  Vector3f::UnitY())
  * AngleAxisf(0.33*M_PI, Vector3f::UnitZ());

您是否尝试过打印该组合旋转矩阵的结果？我敢打赌，当角度为零时，它是对角线1,1,1。

Have you tried printing the result of that combined rotation matrix? I will bet it is diagonal 1,1,1 when the angles are zero.

我对您使用current_q感到困惑。如果滚动，俯仰，偏航对应于某个固定的参考方向，则q将是整个旋转。在这种情况下，

I'm confused about your use of current_q. If roll, pitch, yaw corresponds to some fixed reference direction, then q will be the whole rotation. In that case, this:

current_q=q*current_q;
return current_q;

应该只是

current_q=q;
return current_q;

如果是侧倾，俯仰，偏航当更改当前的欧拉旋转角度（从某个固定参考方向开始）时，存储这些角度并进行相应更改会更容易：

if roll, pitch, yaw are meant as changes to the current euler rotation angles (which start from some fixed reference direction), it's easier to store these angles and change them accordingly:

double m_roll=0, m_pitch=0, m_yaw=0;
 . . .
Eigen::Quaterniond euler2Quaternion(double roll,
              double pitch,
              double yaw)
{
 m_roll+=roll;
 m_pitch+=pitch;
 m_yaw+=yaw;

 Eigen::AngleAxisd rollAngle(m_roll,Eigen::Vector3d::UnitX());
 Eigen::AngleAxisd pitchAngle(m_pitch,Eigen::Vector3d::UnitY());
 Eigen::AngleAxisd yawAngle(m_yaw,Eigen::Vector3d::UnitZ());

 Eigen::Quaterniond q = rollAngle*pitchAngle*yawAngle;
 current_q=q;
 return current_q;
}

在sbabbi的评论中也建议

This is also suggested in a comment by sbabbi

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