使用 pgfplots 的运动图

Question

我正在尝试制作一个运动图，也称为洋葱图，我手工绘制了它，但对结果并不完全满意。红色曲线每次都应该更大，右侧应该更大。有没有办法或多或少地自动完成这个？

\documentclass[border=5pt]{standalone}

\usepackage{tikz}
\usepackage{pgfplots}
\pgfplotsset{compat=newest}

\begin{document}

\begin{tikzpicture}
    \begin{axis}[
    xmin=600,   xmax=2000,
    ymin=0,   ymax=2500,
    xlabel={rev [$rpm$]},ylabel={Torque [$Nm$]},
        height=9cm,
        width=9cm,
        grid=major
    ]
        

    \addplot+[ultra thick,no markers] coordinates {
            (700, 600)
            (850, 900)
            (1100, 2200)
            (1450, 2200)
            (1600, 2000)
            (1800, 1850)
            (1950, 550)
    };

    \addplot+[thick,no markers, smooth,tension=0.8] coordinates {
            (950, 1400)
            (1050, 1000)
            (1190, 990)
            (1260, 1500)
            (1200, 2000)
            (1100, 2200)
    };
    \addplot[thick,no markers, smooth,tension=0.9,red] coordinates {
            (910, 1200)
            (1100, 750)
            (1400, 1100)
            (1600, 2000)
    };
    \addplot[thick,no markers, smooth,tension=0.4,red] coordinates {
            (860, 960)
            (1000, 650)
            (1200, 550)
            (1500, 1000)
            (1750, 1880)
    };


    \node[fill=white] at (1250,1300) {\footnotesize 190 $g/kWh$};
    \node[fill=white] at (1400,1100) {\footnotesize 195};
    \node[fill=white] at (1500,1000) {\footnotesize 200};

    \end{axis}
\end{tikzpicture}

\end{document}