Overview

The BAL parameter group contains specific tuning parameters for Balance Bots (two-wheeled self-balancing robots) running ArduRover.

Unlike standard Rovers, a Balance Bot uses a pitch controller to stay upright. This controller drives the wheels forward/backward to correct pitch errors.

Key Concepts

1. Pitch Control

The robot must constantly adjust its wheel speed to maintain a target pitch angle (usually 0, or leaned forward for acceleration).

• BAL_PITCH_MAX: Limits how far the robot is allowed to lean. If it leans past this, it may fall over or be unable to recover.
• BAL_PIT_FF: Pitch FeedForward. This is critical. It provides the immediate throttle response needed to counter gravity when the robot starts falling.

Parameter Breakdown

• BAL_PITCH_MAX: Maximum pitch angle (deg).
• BAL_PITCH_TRIM: Pitch angle offset for "Level" (balance point).
• BAL_PIT_FF: Feed-forward gain.

Integration Guide

Tuning a Balance Bot

1. Level: Calibrate the accelerometer with the robot perfectly balanced.
2. Trim: Use BAL_PITCH_TRIM to find the exact balance point where the motors are quiet.
3. PID: Tune the ATC_ or PSC_ pitch controllers (depending on firmware version) alongside BAL_PIT_FF.