Formula & Calculator
Differential Drive Robot Angular Velocity
Calculates the rotational (turning) velocity of a differential-drive mobile robot from the difference in its wheel velocities and wheelbase width.
Variables
| Symbol | Quantity | Unit |
|---|---|---|
| omega | Robot angular velocity | rad/s |
| v_right, v_left | Velocities of the right and left wheels | m/s |
| L | Distance between the two wheels (wheelbase) | m |
What it means
The angular velocity (ω) of a differential drive robot is proportional to the difference in wheel speeds divided by the distance between wheels (L). This formula is the counterpart to linear velocity. It is used to compute the robot’s turning rate, which is essential for heading estimation and for generating turning motions. In odometry, it integrates to yield orientation change. In control, it is used for trajectory tracking and point‑to‑point navigation. Understanding this is critical for designing and programming differential drive robots.
Worked example
Differential Drive Angular Velocity – Two Detailed Examples
Real‑World| Parameter | Value |
|---|---|
| v_right (m/s) | 1 |
| v_left (m/s) | 0 |
| L (m) | 0.5 |
| Parameter | Value |
|---|---|
| v_right | 3 |
| v_left | 1 |
| L | 0.4 |
Common mistakes
- Differential drive angular velocity: ω = (v_right − v_left) / L – where L is the wheelbase (distance between wheels).
- Sign: Positive rotation counter‑clockwise (right wheel faster).
- Units: v in m/s, L in m → ω in rad/s.
- Wheelbase: Measured between the contact points of the wheels – not the robot width.
- Assumes: No slipping and the robot is in a planar motion.
Applications
Differential drive robot angular velocity, ω = (v_right − v_left)/L, where L is the wheelbase, relates the difference in wheel speeds to the turning rate. This is critical for controlling the robot's orientation. Engineers use this to calculate the required wheel speed commands for desired turning rates, enabling smooth turns and path following. In odometry, it updates the heading angle. This formula is also used in more complex kinematic models for non‑holonomic robots. By combining linear and angular velocity control, robots can follow arbitrary trajectories. Understanding this relation is essential for mobile robot navigation and control.
- Heading control and turning for mobile robots
- Path generation for curved trajectories
- Odometry heading updates for localisation
- Implementation of control laws for autonomous vehicles
- Simulation and analysis of mobile robot dynamics