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LocalLoiterDriver

Description

The function of the Local Loiter Driver is to command the platform to loiter about a desired position (“loiter reference position”) in the local coordinate system using a specified loiter pattern. The service provides for three different loiter patterns: Hover, Polygon, and Race Track. Hover is a special case of loiter where the vehicle stays at or near the specified loiter reference position within a tolerance without specifying or implementing a particular loiter pattern. While hovering, the command specifies whether the vehicle should give priority to maintinaing its XY position or its Z position. A polygon loiter pattern establishes a regular, symmetrical geometry, centered on the loiter point, by specifying the number of vertices and their distance from the loiter reference position. A race track loiter pattern establishes one of two types of loiters (traditional or figure 8), centered on the loiter reference position, by specifying the width and length of the pattern. Polygon and race track loiters allow the direction of travel (clockwise versus counter clockwise) and angular offset (“loiter bearing”) of the pattern to be specified. For figure 8 loiters, the direction of travel refers to the part of the figure-8 pattern governed by the loiter bearing (between 0 and PI). Another commanded input consists of the desired travel speed. The desired travel speed remains unchanged unless a new Set Travel Speed Message is received. The travel speed may then be changed at any time during the loiter.

Messages

The LocalLoiterDriver service uses the following messages.

Internal Events

  • None