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:
-
- the pitch, in (-pi/2, pi/2), corresponds to a rotation around the x-axis;
-
- the roll, in [-pi, pi), corresponds to a rotation around the y-axis;
-
- 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。