signalk-autopilot-emulator-v2

Minimal Signal K plugin that exposes a virtual autopilot through the Autopilot API v2.

It intentionally has no webapp and does not implement legacy v1 PUT handlers. Clients such as SKIP, Freeboard or a dedicated autopilot UI should talk to:

/signalk/v2/api/vessels/self/autopilots/_default

Behaviour

• Registers one virtual autopilot device, virtual by default.
• Publishes API v2 heartbeat updates through app.autopilotUpdate().
• Supports standby and auto states.
• Supports compass, gps, route, windApparent and windTrue modes.
• Publishes a controller output at steering.autopilot.output.turnRate.
• Persists the selected mode, engagement state, target and any active dodge in the plugin data directory, so they are restored after a Signal K restart. Route mode resumes from the current route data rather than a stale heading.

The turn-rate output is in rad/s. Positive values command a turn to starboard. In compass mode the output is proportional to target - heading; in gps mode it is proportional to target - course over ground; in route mode it is proportional to the dynamic route target heading minus heading; in wind modes the sign is reversed because wind angle is relative to the bow.

Target adjustments are helm-directional. In wind modes, +10 commands 10 degrees to starboard and -10 commands 10 degrees to port, even though Signal K wind angles are signed values where port tack is negative.

Targets are rounded to the nearest whole degree before being exposed through the API.

Route mode follows the same simple logic as the legacy emulator work: route target heading is based on bearingTrackTrue, with a bounded correction of -atan(crossTrackError / routeXteLookahead). Positive cross-track error steers left, negative cross-track error steers right. True route bearings are converted to magnetic when navigation.magneticVariation.value is available, so route mode steers against the same magnetic heading input as compass mode.

Default Inputs

• navigation.headingMagnetic.value
• navigation.courseOverGroundTrue.value
• navigation.course.calcValues.bearingTrackTrue.value
• navigation.course.calcValues.crossTrackError.value
• environment.wind.angleApparent.value
• environment.wind.angleTrueWater.value

Inputs are intentionally mode-specific and fixed to the default paths above. compass reads magnetic heading, gps reads course over ground, and route reads the route paths; the plugin does not silently fall back from heading to course over ground.

Install From A Local Pack

npm pack
npm install ./signalk-autopilot-emulator-v2-0.1.7.tgz