UGV Unity Simulator

A Unity-based UGV (Unmanned Ground Vehicle) simulator with ROS2 integration. Features Ackermann steering, sensor simulation (LiDAR, Camera, IMU, GPS), and deterministic rosbag recording.

Previews

Unity	RViz2

Features

• Ackermann Steering Model - Realistic vehicle dynamics with proper Ackermann geometry
• ROS2 Integration - Full bidirectional communication via ROS-TCP-Connector
• Deterministic Simulation - Reproducible sensor data for consistent rosbag recordings
• Sensor Suite
  • IMU (100 Hz) with configurable noise
  • GPS (10 Hz) with configurable origin coordinates
  • LiDAR (10 Hz) - 16-channel, 360° raycast-based point cloud
  • Camera (30 Hz) - RGB image with camera info
  • Wheel encoders and suspension sensors
• TF Broadcasting - Complete transform tree for RViz visualization

Requirements

• Unity 2022.3 LTS or newer
• Universal Render Pipeline (URP)
• ROS-TCP-Connector 0.7.0-preview or newer

Installation

1. Install ROS-TCP-Connector

First, install the ROS-TCP-Connector package:

1. Open your Unity project
2. Go to Window → Package Manager
3. Click the + button → Add package from git URL...
4. Enter:

   https://github.com/Unity-Technologies/ROS-TCP-Connector.git?path=/com.unity.robotics.ros-tcp-connector
   

5. Click Add

2. Install UGV Simulator

After ROS-TCP-Connector is installed:

1. Go to Window → Package Manager
2. Click the + button → Add package from git URL...
3. Enter:

   https://github.com/batuhanozer/ugv-unity-sim.git
   

4. Click Add

ROS2 Setup

Required Packages

On your ROS2 machine, you need:

• ROS-TCP-Endpoint - TCP bridge for Unity communication
• Custom messages package (included in this repo under ros2_ws/)

Running the Bridge

# Terminal 1: Start the TCP endpoint
ros2 run ros_tcp_endpoint default_server_endpoint --ros-args -p ROS_IP:=0.0.0.0

# Terminal 2: Launch with rosbag recording (optional)
ros2 launch ugv_assignment_bringup record.launch.py

Topics

Published by Unity

Topic	Type	Hz	Description
/clock	rosgraph_msgs/Clock	100	Simulation time
/vehicle/output	ugv_assignment_msgs/Output	50	Vehicle state
/imu/data	sensor_msgs/Imu	100	IMU data
/gps/fix	sensor_msgs/NavSatFix	10	GPS coordinates
/lidar/points	sensor_msgs/PointCloud2	10	LiDAR point cloud
/camera/image_raw	sensor_msgs/Image	30	Camera image
/camera/camera_info	sensor_msgs/CameraInfo	30	Camera intrinsics
/joint_states	sensor_msgs/JointState	50	Wheel positions
/wheel_suspensions	sensor_msgs/JointState	50	Suspension state
/tf	tf2_msgs/TFMessage	50	Transform tree

Subscribed by Unity

Topic	Type	Description
/vehicle/input	ugv_assignment_msgs/Input	Vehicle control commands

Custom Messages

ugv_assignment_msgs/Input

float64 throttle        # 0.0 to 100.0 (percent)
float64 brake           # 0.0 to 100.0 (percent)
float64 steering_angle  # -0.5 to 0.5 (radians)

ugv_assignment_msgs/Output

string state                    # "Parking", "Manual", "Auto"
float64 linear_velocity         # m/s
float64 angular_velocity        # rad/s
float64 front_left_steering_angle   # radians
float64 front_right_steering_angle  # radians

Usage

Vehicle Control

The vehicle can be controlled in two modes:

• Manual Mode - Keyboard/joystick input directly controls the vehicle

  • W/S or Up/Down - Throttle/Brake
  • A/D or Left/Right - Steering
  • Space - Brake

• Auto Mode - Vehicle responds to /vehicle/input topic from ROS2

Deterministic Simulation

The simulator uses Unity's fixedDeltaTime for physics and publishes /clock for ROS2 time synchronization. To record deterministic rosbags:

ros2 bag record --use-sim-time /clock /imu/data /gps/fix /lidar/points /camera/image_raw ...

License

MIT License - see LICENSE for details.

Acknowledgments

• Unity Robotics Hub
• ROS-TCP-Connector