APOLLO中车辆坐标系、GPS坐标系的

apollo 中关于坐标系的定义

Any orientation of a rigid body on a 3-D space can be achieved by

• composing three rotations about the axes of an orthogonal coordinate system.
• These rotations are said to be extrinsic if the axes are assumed to be
• motionless, and intrinsic otherwise. Here, we use an intrinsic referential,
• which is relative to the car’s orientation.
• Our vehicle reference frame follows NovAtel’s convention:
• Right/Forward/Up (RFU) respectively for the axes x/y/z.
• In particular, we describe the orientation of the car by three angles:
• 1. the pitch, in (-pi/2, pi/2), corresponds to a rotation around the x-axis;
• 2. the roll, in [-pi, pi), corresponds to a rotation around the y-axis;
• 3. the yaw, in [-pi, pi), corresponds to a rotation around the z-axis.
• The pitch is zero when the car is level and positive when the nose is up.
• The roll is zero when the car is level and positive when the left part is up.
• The yaw is zero when the car is facing North, and positive when facing West.
• In turn, in the world frame, the x/y/z axes point to East/North/Up (ENU).
• These angles represent the rotation from the world to the vehicle frames.

中文翻译如下

*我们的车辆参考框架遵循NovAtel的惯例:

• x/y/z轴分别为右/前/上(RFU)。
  *我们特别用三个角度来描述汽车的方向:
• 1)在(- pi/2，pi/2)中，螺距对应绕x轴的旋转;
• 2)滚动，在[-pi, pi)，相当于绕y轴旋转;
• 3)偏航，在[-pi, pi)中，相当于绕z轴旋转。
  *汽车水平时俯仰为零，机头向上时俯仰为正。
  *当汽车水平时，横摇为零;当左侧上升时，横摇为正。
  *汽车朝北时偏航为零，朝西时偏航为正。##意思逆时针为正
  反过来，在世界坐标系中，x/y/z轴指向东/北/上(ENU)。
  *这些角度代表从世界到车架的旋转。

但需要特别注意，在localization里规定，正东才是零；我的理解在融合时是做了转换的，但没有看到具体转换的函数在哪