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Evan Palmer

Publications and source records attributed to Evan Palmer.

2 recordsLinked to original sources

Underwater Multi-Robot Simulation and Motion Planning in Angler

Deploying multi-robot systems in underwater environments is expensive and lengthy; testing algorithms and software in simulation improves development by decoupling software and hardware. However, this requires a simulation framework that closely resembles the real-world. Angler is an open-source framework that simulates low-level communication protocols for an onboard autopilot, such as ArduSub, providing a framework that is close to reality, but unfortunately lacking support for simulating multiple robots. We present an extension to Angler that supports multi-robot simulation and motion planning. Our extension has a modular architecture that creates non-conflicting communication channels between Gazebo, ArduSub Software-in-the-Loop (SITL), and MAVROS to operate multiple robots simultaneously in the same environment. Our multi-robot motion planning module interfaces with cascaded controllers via a JointTrajectory controller in ROS~2. We also provide an integration with the Open Motion Planning Library (OMPL), a collision avoidance module, and tools for procedural environment generation. Our work enables the development and benchmarking of underwater multi-robot motion planning in dynamic environments.

cs.RO

The Coupling Effect: Experimental Validation of the Fusion of Fossen and Featherstone to Simulate UVMS Dynamics in Julia

As Underwater Vehicle Manipulator Systems (UVMSs) have gotten smaller and lighter over the past years, it is becoming increasingly important to consider the coupling forces between the manipulator and the vehicle when planning and controlling the system. A number of different models have been proposed, each using different rigid body dynamics or hydrodynamics algorithms, or purporting to consider different dynamic effects on the system, but most go without experimental validation of the full model, and in particular, of the coupling effect between the two systems. In this work, we return to a model combining Featherstone's rigid body dynamics algorithms with Fossen's equations for underwater dynamics by using the Julia package RigidBodyDynamics.jl. We compare the simulation's output with experimental results from pool trials with a ten degree of freedom UVMS that integrates a Reach Alpha manipulator with a BlueROV2. We validate the model's usefulness and identify its strengths and weaknesses in studying the dynamic coupling effect.

cs.RO