멀티콥터 설정점 튜닝(궤적 생성기)

This document provides an overview of the multicopter tuning parameters that change the user experience: how fast the vehicle reacts to stick movements or direction changes in missions, the maximum allowed velocity, etc.

In other words, this topic explains how to tune the parameters that affect the value of a desired setpoint rather than those that affect how well the vehicle tracks the setpoint).

이러한 설정값을 생성하는 알고리즘을 "궤적 생성기"라고 합니다.

WARNING

This guide is for advanced users/experts.

TIP

Follow the instructions in the Multicopter PID Tuning Guide before doing any of the tuning described here. 이러한 튜닝 매개변수를 사용하여 잘못된 추적이나 진동을 수정하지 마십시오!

개요

The input to the P/PID controller is a desired setpoint that the vehicle should attempt to track. PID Tuning ("Lower level tuning") aims to reduce the error between the desired setpoint and the estimate of the vehicle state.

The desired setpoint passed to the P/PID controller is itself calculated from a demanded setpoint based on a stick position (in RC modes) or from a mission command. 요구되는 설정값은 빨리 변경 될 수 있습니다 (예 : 사용자가 스틱을 "단계" 0에서 최대값으로 이동하는 경우). 원하는 설정값이 "램프"로 변경되면 기체의 비행 특성이 더 좋아집니다.

Setpoint value tuning ("higher level tuning") is used to specify the mapping between the demanded and the desired setpoints - i.e. defining the "ramp" at which the desired setpoint follows the demanded setpoint.

TIP

Poorly tuned P/PID Gains can lead to instability. Poorly tuned setpoint values cannot result in instability, but may result in either very jerky or very unresponsive reactions to setpoint changes.

비행 모드 궤적 지원

Mission mode used the Jerk-limited trajectory all the time.

Position mode supports the implementations listed below. It uses the acceleration based mapping by default; other types can be set using MPC_POS_MODE.

Altitude mode similarly supports the implementations selected by MPC_POS_MODE, but only for smoothing the vertical component (i.e. when controlling the altitude).

다른 모드는 궤도 튜닝을 지원하지 않습니다.

Position Mode Implementations

The following list provides an overview of the different implementations of how the stick input is interpreted and turned into trajectory setpoints:

• Acceleration based (Default)
  • Horizontal stick input mapped to acceleration setpoints.
  • Intuitive stick feel because it's like pushing the vehicle around.
  • No unexpected tilt changes upon reaching travel speed velocity.
  • Vertical stick input mapped with jerk-limited trajectory.
  • Set in position mode using MPC_POS_MODE=Acceleration based.
• Jerk-limited
  • Used when smooth motion is required (e.g.: filming, mapping, cargo).
  • Generates symmetric smooth S-curves where the jerk and acceleration limits are always guaranteed.
  • May not be suitable for vehicles/use-cases that require a faster response - e.g. race quads.
  • Set in position mode using MPC_POS_MODE=Smoothed velocity.
• Simple position control
  • Sticks map directly to velocity setpoints without smoothing.
  • Useful for velocity control tuning.
  • Set in position mode using MPC_POS_MODE=Direct velocity.

Altitude Mode Implementations

Analogously to position mode implementations these are the implementations for interpreting vertical stick input:

• Jerk-limited
  • Smoothed vertical input.
  • Set in altitude mode with MPC_POS_MODE Smoothed velocity or Acceleration based.
• Simple altitude control
  • Unsmoothed vertical input.
  • Set in altitude mode only when using MPC_POS_MODE=Direct velocity.