Collaborative Object Transportation by Multiple Robots with Onboard Object Localization Algorithm Collaborative object transportation has become a popular study trend with its remarkable application foreground. In previous relevant studies, localization of the transported object has always been accomplished by additional devices rather than robot onboard equipments. This paper presents a generalized multirobot leaderfollower system for collaborative object transportation and an onboard object localization algorithm for trajectory tracking of the target object. In this system, the mobile robots can directly push a cubic object without extra gripping devices, when tracking the reference trajectory. During the control process, the object is regarded as an virtual leader, whose localization information is utilized as the feedback, while the mobile robots are considered as the followers. In absence of external localization systems, the proposed onboard localization algorithm provides the realtime position information of the object using scan data from lidars equipped on the robots. A performed measurement accuracy test shows high precision of this algorithm. Finally, a lanechanging experiment of object transportation is conducted, and it verifies this multirobot leaderfollower system.

Centralized Control Architecture for Cooperative Object Transportation using Multiple Omnidirectional AGVs This paper addresses the problem of cooperative transportation using multiple omnidirectional Automated Guided Vehicles (AGVs). To enhance flexibility and application potentials, mecanumwheeled platform is considered for the proposed multiAGV system while the cooperative transportation is executed without physical linkgripper to fix the object on the AGVs. Therefore, the position and number of AGV is adjustable depending on the size and weight of the transported object. Analysis of force distribution to each AGV during cooperative transportation is presented. Furthermore, the gradient projection method is exploited to regulate internal force according to the operational capability of each AGV. Moreover, an adaptive sliding mode controller is designed for AGV to cope with dynamic uncertainty during cooperative transportation. Stability of the proposed controller is proven by using Lyapunov Theorem. Finally, numerical simulation is presented to demonstrate the performance of the proposed control system.