0x04AD - SetLocalWaypointExt
Description
This message is used to set waypoint data based on the local coordinate system. A local waypoint can have up to six fields to describe it completely. The waypoint is defined in a local coordinate system using the X, Y, and (optionally) Z fields. The desired orientation of the platform at the waypoint is defined using the roll, pitch, and yaw fields. The remaining fields provide the desired waypoint and path tolerances. Only fields 1-3 (presence vector, X, and Y) are required for each waypoint. The presence vector is used to specify if the remaining fields, i.e., roll, pitch, and yaw, are used to further describe each waypoint and the desired orientation at that point and whether tolerances are provided. It uses a variable field allowing platforms to select various methods for specifying altitude or depth. Note that in some applications, particularly air and undersea, position may be a mix of local coordinates for XY position and absolute coordinates for Z/altitude/depth. This only applies if the Z axis for the vehicle coordinate frame is aligned with a vertical axis, e.g. a vector orthogonal to the ground plane. In all other cases, implementations must use Zlocal reporting only. For example, a UUV launched from a USV may need to navigate using local X/Y coordinates based on its launch point (using dead reckoning from its IMU) but rely on direct readings that do not suffer from drift for its Depth and/or Altitude ASF. Note: Path Tolerances may be specified with a lower limit of zero (an unachievable tolerance), which implies a precise point. The reader is cautioned against specifiying a tolerance so small as to exceed the vehicle's cababilities.
Structure
SetLocalWaypointExtLocalWaypointExtRec
LocalWaypointExtRec
Type: Record
| Field # | Field Name | Type | Units | Optional | Interpretation |
|---|---|---|---|---|---|
| 1 | PresenceVector | uint8 | |||
| 2 | X | false | |||
| 3 | Y | false | |||
| 4 | ZPosition | true | |||
| 5 | Roll | uint16 | radian | true | |
| 6 | Pitch | uint16 | radian | true | |
| 7 | Heading | uint16 | radian | true | |
| 8 | WaypointTolerance | uint32 | meter | true | |
| 9 | PathTolerance | uint32 | meter | true |