Synchronized closed path following for a differential drive and manipulator robot

Li, Y., & Nielsen, C. (2017). Synchronized Closed Path Following for a Differential Drive and Manipulator Robot. IEEE Transactions on Control Systems Technology, 25(2), 704–711. https://doi.org/10.1109/TCST.2016.2562578We locally solve a synchronized path-following problem for a heterogeneous multiagent system consisting of a differential drive robot and a serial manipulator. Each is assigned a simple, regular, and closed curve in its output space. The outputs of the systems must approach and traverse their assigned curves while synchronizing their motions along the paths. We use the notion of path-following outputs to facilitate a solution and present a novel synchronization controller and a novel singularity avoidance controller. The controllers are all given in closed form making their implementation straightforward. A numerical simulation is presented, which includes modeling uncertainty to demonstrate the utility of this approach.Partially supported by the Natural Sciences and Engineering Research Council of Canada (NSERC

Adaptive Path Following for an Underactuated Nonholonomic Mobile Manipulator

We investigate an adaptive path following problem for an underactuated nonholonomic mobile manipulator system and closed planar curves. As opposed to adapting to uncertain or unknown dynamics in the plant, we apply an adaptation approach with respect to an unknown geometric path. First, we present a solution to the non-adaptive path following problem using the concept of a path following output and apply it to circular and elliptical paths. To overcome a drawback associated with our first proposed solution and set the stage for our approach to the adaptive case, we apply an approximation approach based on osculating circles for strictly convex closed curves. We transition to the adaptive path following case by first presenting an algorithm to estimate unknown path parameters in the case of a circular path. We use our estimation algorithm and our path following solution for circular paths in an indirect adaptive control scheme. Thereafter, again using the osculating circle of a curve and the approximation technique of our second non-adaptive path following solution, we extend our adaptive solution, under some mild assumptions, for unknown strictly convex closed curves in the plane

Path Following and Output Synchronization of Homogeneous Linear Time-Invariant Systems

This thesis examines two aspects of the path following control design problem for Linear Time-Invariant (L.T.I.) systems assigned closed curves in their output space. In the first part of the thesis we define a path following normal form for L.T.I. systems and study structural properties related to this normal form. We isolate how unstable zero dynamics alter the feasibility of using the path following normal form for control design. In the second half of the thesis we consider a synchronized path following problem for a homogenous multi-agent system and cast the problem as an instance of an output synchronization problem to leverage recent results from the literature. It is desired that each individual agent follow a specified path. The agents communicate with one another over an idealized communication network to synchronize their positions along the path. The main result is the construction of a dynamic feedback coupling that drives all the agents in the network to their respective reference paths while simultaneously synchronizing their positions along the path. Laboratory results are presented to illustrate the effectiveness of the proposed approach

Synchronized Closed Path Following for a Differential Drive and Manipulator Robot

Li, Y., & Nielsen, C. (2017). Synchronized Closed Path Following for a Differential Drive and Manipulator Robot. IEEE Transactions on Control Systems Technology, 25(2), 704–711. https://doi.org/10.1109/TCST.2016.2562578We locally solve a synchronized path-following problem for a heterogeneous multiagent system consisting of a differential drive robot and a serial manipulator. Each is assigned a simple, regular, and closed curve in its output space. The outputs of the systems must approach and traverse their assigned curves while synchronizing their motions along the paths. We use the notion of path-following outputs to facilitate a solution and present a novel synchronization controller and a novel singularity avoidance controller. The controllers are all given in closed form making their implementation straightforward. A numerical simulation is presented, which includes modeling uncertainty to demonstrate the utility of this approach.Partially supported by the Natural Sciences and Engineering Research Council of Canada (NSERC