Problem splitting matix eqations in align environment

Question

I am trying to get my equation to appear like this: however, I am having a problem getting my program to compile properly using this alignat environment. Can you please help my get the equation to show up properly. Thanks.

Here is my code:

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{align}
{\mathbf{u}} & = H^{-1}({\mathbf{P}}_{T}-B) \\
& = \begin{bmatrix}
\sin\theta_{1} & \cos\theta_{1} \\
\cos\theta_{1} & \sin\theta_{1}
\end{bmatrix}^{-1}
\begin{split}
&\left(
\begin{bmatrix}
(L_{1} + \delta r_{3v} + r_{3v})\cos\theta_{1} + r_{2}\sin\theta_{1} \\
(L_{1} + \delta r_{3v} + r_{3v})\sin\theta_{1} - r_{2}\cos\theta_{1}
\end{bmatrix}\right.\\
& \left. - X \right)
\end{split}
\end{align}