lua-vehicle

name	lua-vehicle
description	Write ArduPilot Lua scripts involving vehicle control, movement commands, RC input, or telemetry. Use when the user asks to control the vehicle from Lua.

ArduPilot Lua Vehicle Control

Before writing vehicle control code, read the full playbooks:

1. Read the vehicle control playbook: libraries/AP_Scripting/CODEX_VEHICLE_CONTROL.md — complete reference for movement commands, controller behavior, state/telemetry, RC input
2. Read the general playbook: libraries/AP_Scripting/AGENTS.override.md — applet structure, parameter system, code constraints
3. Read the API docs: libraries/AP_Scripting/docs/docs.lua — verify all function signatures

Task: $ARGUMENTS

Quick Reference

Control Type Hierarchy (safest to most direct)

1. Position — set_target_location(), set_target_pos_NED() — fire-and-forget, fights wind
2. Velocity — set_target_velocity_NED() — continuous command, drifts without correction
3. Angle — set_target_angle_and_climbrate() — continuous, cannot go inverted
4. Rate — set_target_rate_and_throttle() — continuous, full control, CAN go inverted

Critical Rules

• Movement commands only work in Guided mode (or Auto with NAV_SCRIPT_TIME)
• Never mix controller types in the same update() cycle
• Rate controllers need continuous commands — stops rotating if commands stop
• Velocity controllers need continuous commands — drifts if not called
• Position controllers are fire-and-forget

State & Telemetry

• ahrs:get_location() — vehicle position
• ahrs:get_velocity_NED() — velocity in NED frame
• ahrs:get_roll_rad(), get_pitch_rad(), get_yaw_rad() — attitude (use _rad variants, not deprecated bare names)
• ahrs:airspeed_EAS() — airspeed (not deprecated airspeed_estimate())

RC Input

• rc:get_aux_cached(aux_func) — aux switch position (0/1/2)
• rc:get_channel(n):norm_input_dz() — normalized stick input with deadzone
• Read RCMAP_ROLL/PITCH/THROTTLE/YAW params to find control channels

Safety

• Check arming:is_armed() before motor commands
• Check flight mode before movement commands
• Pilot RC input has highest priority — relinquish on stick input
• Never interfere with failsafe mechanisms