Formation Control for Mobile Robots with Saturated Driving

Abstract

This paper deals with formation control of mobile robots whose actuators are saturated. Each mobile robot has two independent wheels that are driven by their rotational speeds as control input. Each mobile robot also has a virtual vehicle and consensus of all of the virtual vehicles enables us to achieve formation of the mobile robots. If each mobile robot has saturation on their rotational speeds of the wheels, standard consensus protocols cannot achieve formation of the mobile robots as well as consensus of the virtual vehicles. To cope with this issue, this paper discusses a time-varying gain in the consensus protocol that is introduced so as not to saturate the rotational speeds. This paper also proposes a design method of the time-varying gains which are not common for the mobile robots and are able to improve the convergence speed of formation. The paper finally shows an experiment of formation control with hand made mobile robots as well as numerical examples.