Tham khảo tài liệu 'swarm robotics, from biology to robotics part 8', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Key Aspects of PSO-Type Swarm Robotic Search Signals Fusion and Path Planning 63 Fig. 4. Motion Control of A WMR Similarly the orientation di t At f a at position P2 with Vi t At vil Vi2 t At can be decided too. Therefore the required expected turning angle fii from pi to P2 can be computed and used to further decide wp n . Vi2 t At Vi2 t A fa arctan - arctan 4 pi Vii t At Vii t v The posture vectors xị yi di T of robot Rị are required as control inputs to individual controller at each time step depending on the posture estimate with incremental encoder data odometry . Assume the angular wheel displacements having been measured during the sampling time At by the encoders. We can further obtain the linear and angular displacements As and Ad. Then the estimate of posture at time t At can be computationally decided Oriolo et al. 2002 Siegwart Nourbakhsh 2004 x y d t At x y d Ascos d As sin d Ad AS A 2 A 2 t 5 Modeling for Swarm Robots Our swarm robotic system is composed of the above-mentioned robots. The meanings of used symbols are as follows Pi xil xi2 and Vi vil vi2 are position and linear velocity z-v-i- R al tiifip Ỉ Ăyíd 17 n Í Y v _ and n Í Y V 1 1 1 ÍO I lid iaf ir al o root i at t r Pi xil xi2 an p i x i 1 x i 2 te est stoiicai positions of robot i itself and its communication-based neighborhood Pugh et al. 2006 . Based on this we can define the best position within its neighborhood Xue Zeng 2008 Xue et al. 2009 p i t p t argk max I p t k e Ri s neighborhood 6 where I is the fusion of measurement readings of target signals. Further we are able to model swarm robotic system with the extended PSO method 64 Swarm Robotics From Biology to Robotics vij t 1 ĩivij t c1r1 xij - xij c2r2 x i j - xij vij t At vij t Ki vij t 1 - vij t xjt At Xịj t Vij t At At 7 where Vij t and Xij t are j-dimensional velocity and position of robot Ri at time t respectively Vij t 1 the expected computational velocity Ki designed parameter of local controller gain
