pdf_tex files and import: PDF file not found

I am currently working on my PhD thesis, and I am having trouble including a pdf_tex and pdf file created using Inkscape. I am using TeXStudio and PDFLaTeX.

The relevant files are:

phd_thesis_all/phd_thesis/tex/thesis.tex
phd_thesis_all/phd_thesis/tex/Chapter05/teleoperation.tex
phd_thesis_all/phd_thesis_figs/images/teleoperation/solidworks_model_view.pdf_tex
phd_thesis_all/phd_thesis_figs/images/teleoperation/solidworks_model_view.pdf
phd_thesis_all/phd_thesis_figs/images/teleoperation/solidworks_model_view.png
phd_thesis_all/phd_thesis_figs/images/teleoperation/solidworks_model_view.svg

The svg has added annotations to the png file. This is exported as a pdf and pdf_tex file for use in the thesis.

The command to include the file with the diagram is in thesis.tex.

    % Chapter 5
    FloatBarrier
    chapter{Teleoperation}
    label{ch:teleoperation}
    include{Chapter05/teleoperation}

The figure import command in Chapter05/teleoperation.tex is:

    begin{figure}[htb]
    centering
    import{../../phd_thesis_figs/}{images/teleoperation/solidworks_model_view.pdf_tex}
    caption{SolidWorks Model with Coordinate Systems Highlighted}
    label{fig:solidworks_model_view}
    end{figure}

When I try to compile the document, it comes up with the error:

(../../phd_thesis_figs/images/teleoperation/solidworks_model_view.pdf_tex

LaTeX Warning: File `solidworks_model_view.pdf' not found on input line 52.


! Package pdftex.def Error: File `solidworks_model_view.pdf' not found.

See the pdftex.def package documentation for explanation.
Type  H <return>  for immediate help.
 ...                                              

l.52 ...length,page=1]{solidworks_model_view.pdf}}
                                                  %
?

In other words, it is finding the .pdf_tex file just fine, but is choking on the includegraphics command inside to get the pdf file. I thought the import command modified the search paths for files in its command. My graphicspath is set so I can import graphics file from that directory tree just fine.

If I change the figure inclusion to:

    includegraphics[width=linewidth]{images/teleoperation/solidworks_model_view.png}

Everything works perfectly fine. Why can I not do the same with import and pdf_tex files?

For completeness, here is the pdf_tex file generated by Inkscape. THe offending includegraphics directive is on line 52.

    %% Creator: Inkscape 0.91_64bit, www.inkscape.org
    %% PDF/EPS/PS + LaTeX output extension by Johan Engelen, 2010
    %% Accompanies image file 'solidworks_model_view.pdf' (pdf, eps, ps)
    %%
    %% To include the image in your LaTeX document, write
    %%   input{<filename>.pdf_tex}
    %%  instead of
    %%   includegraphics{<filename>.pdf}
    %% To scale the image, write
    %%   defsvgwidth{<desired width>}
    %%   input{<filename>.pdf_tex}
    %%  instead of
    %%   includegraphics[width=<desired width>]{<filename>.pdf}
    %%
    %% Images with a different path to the parent latex file can
    %% be accessed with the `import' package (which may need to be
    %% installed) using
    %%   usepackage{import}
    %% in the preamble, and then including the image with
    %%   import{<path to file>}{<filename>.pdf_tex}
    %% Alternatively, one can specify
    %%   graphicspath{{<path to file>/}}
    %% 
    %% For more information, please see info/svg-inkscape on CTAN:
    %%   http://tug.ctan.org/tex-archive/info/svg-inkscape
    %%
    begingroup%
      makeatletter%
      providecommandcolor[2][]{%
        errmessage{(Inkscape) Color is used for the text in Inkscape, but the package 'color.sty' is not loaded}%
        renewcommandcolor[2][]{}%
      }%
      providecommandtransparent[1]{%
        errmessage{(Inkscape) Transparency is used (non-zero) for the text in Inkscape, but the package 'transparent.sty' is not loaded}%
        renewcommandtransparent[1]{}%
      }%
      providecommandrotatebox[2]{#2}%
      ifxsvgwidthundefined%
        setlength{unitlength}{1680bp}%
        ifxsvgscaleundefined%
          relax%
        else%
          setlength{unitlength}{unitlength * real{svgscale}}%
        fi%
      else%
        setlength{unitlength}{svgwidth}%
      fi%
      globalletsvgwidthundefined%
      globalletsvgscaleundefined%
      makeatother%
      begin{picture}(1,0.60119048)%
        put(0,0){includegraphics[width=unitlength,page=1]{solidworks_model_view.pdf}}%
        put(0.80420207,0.1664867){color[rgb]{0,0,0}makebox(0,0)[lb]{smash{$z$}}}%
        put(0.77685686,0.12356509){color[rgb]{0,0,0}makebox(0,0)[lb]{smash{$x$}}}%
        put(0.7926602,0.10007423){color[rgb]{0,0,0}makebox(0,0)[lb]{smash{$y$}}}%
      end{picture}%
    endgroup%

includepackage{import}

import{path/to/file/}{thefile.pdf_tex}

$ENV{'TEXINPUTS'}='./graphics//:'.$ENV{'TEXINPUTS'};