For out of doors robotics, one of many key capabilities for autonomous use-cases is GPS Waypoint Navigation.
Should you’re unfamiliar with the time period, GPS Waypoint Navigation is the flexibility to offer a robotic with a set of GPS waypoints (i.e., a set of latitude / longitude pairs), and have the robotic autonomously navigate from its present location to every of the outlined waypoints. An added bonus can be not bumping into something alongside the way in which.
This has been performed in analysis initiatives and papers quite a few occasions, however scalable {hardware} and software program packages to allow this on manufacturing prepared subject robots are few and much between.
That’s why Clearpath and Veerum, with the assistance of a Mitacs grant, partnered with Steve Phillips, a civil engineering graduate scholar from the College of Waterloo. Steve’s analysis is a cross between mechanical and structural engineering, specializing in utilizing cellular robots to carry out infrastructure evaluation and inspection. For this mission with Clearpath, he’s developed a sturdy, repeatable GPS Waypoint Navigation system for Clearpath’s household of out of doors robots.
Over the previous semester, Steve has been working away at deciding on and integrating the proper payload suite, perfecting the fusion of sensor information, and making a usable interface to simply choose a waypoint and ship the robotic on its means.
THE SETUP
For growth and testing of the GPS navigation software program, Steve’s major setup consisted of a Jackal UGV, paired with the rugged Duro GPS from Swift Navigation and the UM7 inertial measurement unit (IMU) from Redshift Labs. Along with supporting excessive accuracy RTK, the Duro features a in-built Bosch BMI160 IMU and BMM150 Magnetometer. To confirm that the software program capabilities {hardware} agnostically, Steve and the Clearpath software program workforce additionally deployed it on the a lot bigger Warthog UGV (outfitted with a Novatel GPS and a Lord GX5-25 IMU). Working autonomy software program on a 500 lb robotic might be scary, so we’re glad that the system was totally examined beforehand, and works completely!
GPS waypoint navigation consists of two key elements: localization, and navigation. Localization is accountable for utilizing the robotic sensors (i.e., the UGV wheel encoders, IMU information, and gps measurements) to estimate the place of the robotic. Navigation is accountable for sending the UGV wheel velocity instructions which transfer it to the specified vacation spot (e.g., a waypoint). By using a mix of tried-and-true ROS packages, in addition to some new & leading edge navigation packages unveiled at ROSCON 2017 (see this video and this video for extra data), the GPS waypoint navigation framework is powerful and dependable, but in addition extremely configurable and simply extensible to include updates.
MISSIONS
One other essential element of the GPS navigation answer is the interface used to outline and ship waypoints, in addition to visualize the robotic and its setting because it navigates. Within the present framework, customers create (or load current) “missions”, that are despatched to the robotic to provoke navigation.
A mission is outlined as follows:
- Each mission consists of a set of waypoints
- Every waypoint is outlined by:
- A place (latitude, longitude, heading)
- A set of ‘viapoints’, which outline the trail that the robotic ought to take to reach on the waypoint. Viapoints are used to make sure that the robotic takes the specified route between waypoints, avoiding any non-moving obstacles (like buildings) or different off-limit areas.
- An inventory of duties to execute as soon as the robotic arrives on the waypoint (e.g., take a photograph, gather a 3d scan, wait, and many others.)
With this framework, the idea of easy point-to-point navigation has been prolonged to offer an answer that higher meets the necessities we see in actual world functions.
Through the use of the acquainted, top-down, satellite tv for pc view we see in Google Maps, establishing autonomy missions for the robotic may be very intuitive.
APPLICATION SOFTWARE PACKAGE SUITE
Whereas Steve was solely with Clearpath for the semester, his work has turn into a part of Clearpath’s line of utility Software program Packages. These packages are designed to allow autonomy and teleoperation throughout quite a few completely different functions, and the GPS Waypoint Navigation stack completely enhances the opposite obtainable packages.
Should you’re engaged on an utility that might profit from out of doors autonomy, check out the GPS Waypoint Navigation package deal, in addition to the opposite obtainable autonomy software program.
For extra details about the GPS Waypoint Navigation package deal, or to share some particulars about your personal mission with us, click on the hyperlink under!
