Differential Drive Base

差速底盘Advanced

A mobile base with two independently driven wheels that steers by varying the speed of each side.

A differential drive base is the most common mobile-robot chassis: an independently motor-driven wheel on the left and right, plus one or two caster wheels for support. Driving both wheels at the same speed goes straight, different speeds turn, and opposite directions spin the robot in place. It's mechanically simple, cheap, and easy to control — its kinematics need only two parameters, wheel speed and wheel separation, to compute the base's linear and angular velocity — so it's used in robot vacuums, the TurtleBot, and many warehouse AMRs. Its downside is that it can't translate sideways (it's a nonholonomic system) and is less agile than a Mecanum-wheel or swerve-drive base at repositioning in tight spaces. In ROS, it's typically commanded directly with linear and angular velocity over the cmd_vel topic.

ExampleA robot vacuum is a textbook differential drive base: two drive wheels plus one front caster, able to spin in place but not move sideways.

Also called: Differential Drive, Two-Wheel Differential Base
Related: Mobile Base (Chassis) · Differential Drive Kinematics · Nonholonomic Constraint · Mecanum Wheel · Swerve Drive · Wheel Odometry
Sources: Differential wheeled robot - Wikipedia