White Paper: Robust Tracking Control of Mobile Robot Formation with Obstacle Avoidance
In this paper, we suggest a robust formation tracking scheme for a team of constrained wheeled mobile robots (WMRs) in the environment with obstacles. Our first main result is that the problem of finding the collision-free trajectory for the robots can be formulated as a nonconvex optimization problem under general convex obstacle assumption and solved using MILP method. Our second main result concerns moving horizon formation control of multiple mobile robots with parametric uncertainties and actuator saturations.
We consider the formation control problem of multiple wheeled mobile robots with parametric uncertainties and actuator saturations in the environment with obstacles. First, a nonconvex optimization problem is introduced to generate the collision-free trajectory. If the robots tracking along the reference trajectory find themselves moving close to the obstacles, a new collision-free trajectory is generated automatically by solving the optimization problem. Then, a distributed control scheme is proposed to keep the robots tracking the reference trajectory. For each interacting robot, optimal control problem is generated. And in the framework of LMI optimization, a distributed moving horizon control scheme is formulated as online solving each optimal control problem at each sampling time.Moreover, closed-loop properties inclusive of stability and H∞ performance are discussed. Finally, simulation is performed to highlight the effectiveness of the proposed control law.
Annual Salary Survey
After almost a decade of uncertainty, the confidence of plant floor managers is soaring. Even with a number of challenges and while implementing new technologies, there is a renewed sense of optimism among plant managers about their business and their future.
The respondents to the 2014 Plant Engineering Salary Survey come from throughout the U.S. and serve a variety of industries, but they are uniform in their optimism about manufacturing. This year’s survey found 79% consider manufacturing a secure career. That’s up from 75% in 2013 and significantly higher than the 63% figure when Plant Engineering first started asking that question a decade ago.