Integrating path planning and robot control

07 March 2011

share this:

There is often a conflict between planning the path a robot should take to achieve a desired task (high-level control) and the motion control needed for the robot to follow this path (low-level control). The problem is that if you decouple the path planning from the robot control, you might end up with paths that are impossible for the robot to follow because of physical constraints. Fully coupling the high-level and low-level control would solve this problem, although such intricate controllers are typically difficult to design.

To solve these shortcomings, Conner et al. propose a hybrid control strategy that combines low-level and high-level control in a smart way. As a test case, they consider a scenario where a robot needs to reach a goal while avoiding obstacles. The robot has a non-trivial body shape and is nonholonomic, meaning that it can not turn on the spot. The approach they developed is shown in the figure below. Local control policies, showed by fennel-shapped sets with vector field arrows, are responsible for making the robot drive towards a local goal. These policies respect the low-level dynamics and kinematics of the robot. A set of control policies can then be followed sequentially to reach a desired high-level behavior. To find the best path, an abstract tree representing the transitions between control policies is used.

Experiments were done with a LAGR robot in a fully known environment and with visual localization using landmarks. Results show that the method is successful in safely guiding the nonholonomic robot to its goal in an obstacle prone environment and that disturbances do not require the robot to replan its course.

Sabine Hauert is President of Robohub and Associate Professor at the Bristol Robotics Laboratory
Sabine Hauert is President of Robohub and Associate Professor at the Bristol Robotics Laboratory

Related posts :

Robot Talk Episode 86 – Mario Di Castro

In the latest episode of the Robot Talk podcast, Claire chatted to Mario Di Castro from CERN all about robotic inspection and maintenance in hazardous environments.
24 May 2024, by

Congratulations to the #ICRA2024 best paper winners

The winners and finalists in the different categories have been announced.
20 May 2024, by

Robot Talk Episode 85 – Margarita Chli

In the latest episode of the Robot Talk podcast, Claire chatted to Margarita Chli from the University of Cyprus all about vision, navigation, and small aerial drones.
17 May 2024, by

What’s coming up at #ICRA2024?

Find out what's on the programme at the IEEE International Conference on Robotics and Automation.
10 May 2024, by

Octopus inspires new suction mechanism for robots

Suction cup grasping a stone - Image credit: Tianqi Yue The team, based at Bristol Robotics Laboratory, studied the structures of octopus biological suckers,  which have superb adaptive s...
18 April 2024, by

Open Robotics Launches the Open Source Robotics Alliance

The Open Source Robotics Foundation (OSRF) is pleased to announce the creation of the Open Source Robotics Alliance (OSRA), a new initiative to strengthen the governance of our open-source robotics so...

Robohub is supported by:

Would you like to learn how to tell impactful stories about your robot or AI system?

training the next generation of science communicators in robotics & AI

©2024 - Association for the Understanding of Artificial Intelligence


©2021 - ROBOTS Association