Hardware Requirements
OutdoorNav Software works with compatible UGVs, either from Clearpath Robotics or third parties. High level requirements for compatible UGVs are outlined below. Detailed qualification requirements are outlined in UGV Integration Requirements.
Requirements
OutdoorNav software does not communicate directly with the UGV motors. Rather, it publishes target linear and angular velocities packaged in the ROS Twist message format and relies on the low level velocity controller of the vehicle to translate these velocities into correct motor control commands. Therefore, OutdoorNav Software requires that the UGV must accept the control commands sent in the ROS Twist message format. More detailed requirements are outlined in the following table.
| # | Requirement | Notes |
|---|---|---|
| 1 | The UGV must be a differential drive or Ackermann drive configuration | Ackerman drive is currently available as a custom implementation; standard in 2023 |
| 2 | The UGV must have velocity control of the wheels and provide kinematic control of the platform | |
| 3 | The UGV shall provide odometry feedback of the wheel direction and velocities and/or steering position | Recommended encoder resolution of 500 ticks per revolution or greater |
| 4 | The UGV should have an emergency stop system with status feedback | |
| 5 | The UGV must accept ROS 1 Twist Commands on the /cmd_vel topic | See: API Endpoints; ROS 2 interface available in future release |
| 6 | The UGV must provide odometry and status feedback through ROS topics | See: API Endpoints |
Typical Hardware
While a variety of different sensors and equipment can be used with OutdoorNav Software, the following are used most commonly:
- Clearpath Robotics UGV: Jackal, Husky or Warthog
- GPS System: Dual DURO RTK system or NovAtel Terrastar
- IMU: Microstrain 3DM-GX5-25
- 3D Laser Sensor: Velodyne VLP-16
- Tablet Computer: Getac F110
- Clearpath Long Range Network Station with RTK corrections ("Base Station")