Coordination of nonholonomic mobile robots for diffusive threat defense. Issue 8 (May 2019)

• Record Type: Journal Article
• Authors: Luo, Kai; Guan, Zhi-Hong; Cai, Chang-Xin; Zhang, Ding-Xue; Lai, Qiang; Xiao, Jiang-Wen
• Is Part Of: Journal of the Franklin Institute. Volume 356:Issue 8(2019)
• Page Start: 4690
• Page End: 4715
• Publication Date: 2019-05
• Subjects: Science -- Periodicals; Technology -- Periodicals; Patents -- United States -- Periodicals; 505
• DOI: 10.1016/j.jfranklin.2019.03.014
• Languages: English
• ISSNs: 0016-0032

Abstract

Abstract: This paper studies coordination of a team of nonholonomic mobile robots with smart actuators for defending against invasive threat to a planar convex area. The threat refers to a kind of harmful substance such as chemical pollutant appearing outside and moving towards the area. The invasion of threat can be modeled by a 2D unsteady reaction-diffusion process. To reflect the adverse effect of threat on the area, a so-called risk intensity field is introduced. The value of risk intensity is equal to the concentration of threat measured by a static mesh sensor network. Based on this risk intensity field, a coordination control scenario using Voronoi tessellation is formulated. In order to minimize the actuator performance loss and reduce the total average risk intensity simultaneously, a generalized centroidal Voronoi tessellation (CVT) algorithm including optimal motion control and risk mitigation control is designed. The proposed algorithm is gradient-based and guides mobile robots to track their optimal trajectories asymptotically. Meanwhile, two conditions of choosing control gains are derived to keep the total average risk intensity below a safety level. Several simulation examples with different cases of threat invasion are provided and the advantage of proposed algorithm over traditional control method is presented.