fjp/frenet

Transform Frenet (s,d) to local Cartesian (x,y) coordinates.

frenet's Issues

error in calculating curvature?

frenet/python/src/cubic_spline_planner.py

Line 167 in a7e8dd5

k = (ddy * dx - ddx * dy) / (dx ** 2 + dy ** 2)

It seems that the divisor should be $(x'**2 + y'**2)^{3/2}$?

Frenet to Cartesian Coordinates

Hello,

I have some doubts in the FRT2Cart function in MATLAB.

    nNextRefPoint = 0;

    while ((i_fS > i_faRefRunLength(nNextRefPoint+1)) && (nNextRefPoint < length(i_faRefRunLength)))

        nNextRefPoint = nNextRefPoint + 1;
    end

    nPrevRefPoint = nNextRefPoint-1;

Can you please explain me what these variables mean? And what exactly is happening here?

Transform between cartesian and frenet coordinate system

Hi @fjp , I'm working on my own version of this algorithm to generate a local path to avoid obstacles.
Currently I have a problem which I have no idea about how to fix. Here is the image to show my problem, the pink path is the original reference path, the left blue path is the generated path to avoid the obstacle lies on the original path, and the red circle marks my problem. When I try to convert my path from Frenet coordinate (s, d) to Cartesian coordinate (x, y), sometimes the path will suddenly turn back like the red circle part shows.

I use the spline function to map between s-to-x and s-to-y according to the original reference path. And I calculate the new path point which has d distance away from the original reference path and is perpendicular to the tangent direction of the relative point on the original path. I think the problem is coming from the curvature of the original path, but I have no idea about how to fix it. Can you give me some suggestion?

Difference in Cart2FRT and FRT2Cart in transformation.m

Hi Franz,

I would first like to thank you for building such a repo. I was trying out the transformation.m file. At the end of the code, we compare transform from Cartesian to Frenet and back to Cartesian. The results are not the same and we have some error in both the x and y positions. I thought this could be due to the ds=0.1. However, reducing ds by orders of magnitude did not help much in reducing the error. Is there any specific reason for this or is there a bug in the code that we need to look for?

Thanks,
Iman

image frame-components.jpg is missing for README

Hello Franz,

Would you like to upload the missing picture to complete the README, please? That would be much helpful.

Thank you
Yang

There is an error about Qt when running

python main.py 
['/home/ugv-yu/bryan/Frenet/frenet/python', '/usr/local/lib/python2.7/dist-packages/cryptography-2.4.2-py2.7-linux-x86_64.egg', '/usr/local/lib/python2.7/dist-packages/cffi-1.11.5-py2.7-linux-x86_64.egg', '/usr/local/lib/python2.7/dist-packages/asn1crypto-0.24.0-py2.7.egg', '/usr/local/lib/python2.7/dist-packages/idna-2.8-py2.7.egg', '/usr/local/lib/python2.7/dist-packages/pycparser-2.19-py2.7.egg', '/home/ugv-yu/catkin_ws/devel/lib/python2.7/dist-packages', '/home/ugv-yu/Autoware/ros/devel/lib/python2.7/dist-packages', '/opt/ros/kinetic/lib/python2.7/dist-packages', '/usr/share/qgis/python', '/usr/lib/python2.7', '/usr/lib/python2.7/plat-x86_64-linux-gnu', '/usr/lib/python2.7/lib-tk', '/usr/lib/python2.7/lib-old', '/usr/lib/python2.7/lib-dynload', '/home/ugv-yu/.local/lib/python2.7/site-packages', '/usr/local/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages/PILcompat', '/usr/lib/python2.7/dist-packages/gtk-2.0', '/usr/lib/python2.7/dist-packages/wx-3.0-gtk2']
['/home/ugv-yu/bryan/Frenet/frenet/python', '/usr/local/lib/python2.7/dist-packages/cryptography-2.4.2-py2.7-linux-x86_64.egg', '/usr/local/lib/python2.7/dist-packages/cffi-1.11.5-py2.7-linux-x86_64.egg', '/usr/local/lib/python2.7/dist-packages/asn1crypto-0.24.0-py2.7.egg', '/usr/local/lib/python2.7/dist-packages/idna-2.8-py2.7.egg', '/usr/local/lib/python2.7/dist-packages/pycparser-2.19-py2.7.egg', '/home/ugv-yu/catkin_ws/devel/lib/python2.7/dist-packages', '/home/ugv-yu/Autoware/ros/devel/lib/python2.7/dist-packages', '/opt/ros/kinetic/lib/python2.7/dist-packages', '/usr/share/qgis/python', '/usr/lib/python2.7', '/usr/lib/python2.7/plat-x86_64-linux-gnu', '/usr/lib/python2.7/lib-tk', '/usr/lib/python2.7/lib-old', '/usr/lib/python2.7/lib-dynload', '/home/ugv-yu/.local/lib/python2.7/site-packages', '/usr/local/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages/PILcompat', '/usr/lib/python2.7/dist-packages/gtk-2.0', '/usr/lib/python2.7/dist-packages/wx-3.0-gtk2']
Create Frenet Main Window
('create DynamicsWidget', <PySide2.QtWidgets.QWidget object at 0x7f231cc6df80>)
(u'new MplWidget', <PySide2.QtWidgets.QWidget object at 0x7f231cc6df80>)
Traceback (most recent call last):
  File "main.py", line 24, in <module>
    oFrenetMainWindow = fmw.FrenetMainWindow()
  File "/home/ugv-yu/bryan/Frenet/frenet/python/gui/frenet_main_window.py", line 7, in __init__
    self.setupUi(self)
  File "/home/ugv-yu/bryan/Frenet/frenet/python/gui/ui/frenet_main_window_ui.py", line 25, in setupUi
    self.dynamics_widget = DynamicsWidget(self.centralwidget)
  File "/home/ugv-yu/bryan/Frenet/frenet/python/gui/widgets/dynamics_widget.py", line 18, in __init__
    super(DynamicsWidget, self).__init__(self.oFig, parent)
  File "/home/ugv-yu/bryan/Frenet/frenet/python/gui/widgets/mplwidget.py", line 25, in __init__
    self.canvas = MplCanvas(i_oFig)                  # Create canvas object
  File "/home/ugv-yu/bryan/Frenet/frenet/python/gui/widgets/mplwidget.py", line 17, in __init__
    Canvas.setSizePolicy(self, QtWidgets.QSizePolicy.Preferred, QtWidgets.QSizePolicy.Preferred)
TypeError: arguments did not match any overloaded call:
  QWidget.setSizePolicy(QSizePolicy): argument 2 has unexpected type 'PySide2.QtWidgets.QSizePolicy.Policy'
  QWidget.setSizePolicy(QSizePolicy.Policy, QSizePolicy.Policy): argument 2 has unexpected type 'PySide2.QtWidgets.QSizePolicy.Policy'

When I use python main.py in terminal, the above is unfolded there. I think there is an mismatch for PySide2 library maybe. The following is shown in my terminal.

>>> import PySide2
>>> print(PySide2.__version__)
2.0.0~alpha0

wrong polynomial coefficients in cQuarticPoly.m

Some polynomial coefficients are wrong in cQuarticPoly.m.

It should be:

line 30: x = obj.c(2) + 2 * obj.c(3).*t + 3 * obj.c(4).*t.^2 + 4 * obj.c(5).*t.^3;

line 34: x = 2 * obj.c(3) + 6 * obj.c(4).*t + 12 * obj.c(5).*t.^2;

Readme.md Transformation headline broken image.jpg

Hi! Just started reading Readme file. It seems that there is a corrupted image file under Transformation headline possibly named: frame-components.jpg file.
Thanks