怎样设计履带驱动装置？

大家好，请问怎样设计履带带动箱体运动的装置？怎样实现直线走和拐弯呢？特别是拐弯，我想参考汽车的做法的，可是汽车是轮式的，不符合要求，大家知道怎样设计吗？小弟在此深表谢意！ 就像这样的： $("swf_GlC").innerHTML=AC_FL_RunContent("width", "700", "height", "530", "allowNetworking", "internal", "allowScriptAccess", "never", "src", encodeURI("http://player.youku.com/player.php/sid/XMzQwNTQ0NTQw/v.swf"), "quality", "high", "bgcolor", "#ffffff", "wmode", "transparent", "allowfullscreen", "true");