Adaptive backstepping asymptotic consensus tracking control of multiple uncertain manipulators with disturbances

To improve the disadvantages of signal control and energy control, a cooperative control strategy combining signal control and energy control is proposed for manipulators driven by permanent magnet synchronous motors (PMSMs) in this article. The cooperative control strategy is achieved by way of the convex combination of signal controller and energy controller, and Gaussian function is selected as cooperative function. The energy controller applies variable damping error port Hamiltonian and the signal controller uses backstepping nonsingular terminal sliding mode control. The PMSM with loss model is applied to obtain higher efficiency. To deal with modeling errors and joint friction, a nonlinear disturbance observer is used for manipulators system. Simulation and experiment results display that the designed strategy not only increases efficiency, but also enhances dynamic and steady‐state performance of manipulators.

Cooperative control of variable damping error port Hamiltonian and backstepping nonsingular terminal sliding mode control for manipulators driven by PMSMs

Guo,

Yu,

Yang

et al. 2024

Strong consensus of convex second‐order multi‐agent systems with time‐varying topologies

Jin,

Liu,

Cao

et al. 2024

SummaryThis paper addresses the strong consensus problem of convex second‐order discrete‐time multi‐agent systems (MASs) with time‐varying topologies. The convex second‐order discrete‐time MAS model is derived from the Langevin equation and therefore has a certain physical significance. The strong consensus here means that all the first‐ and second‐order states converge to an identical value. Some fully distributed control protocols are designed with time‐varying weights randomly chosen from an arbitrary finite set. These protocols are applicable to several cases where changing topologies may be directed or undirected, and connected or disconnected. As a special case, the condition for convex second‐order MASs with fixed topologies to achieve the strong consensus is presented. Finally, two simulation examples illustrate the proposed results.

Command filtering‐based adaptive backstepping control for a class of discrete‐time uncertain nonlinear systems with mismatched disturbances

Sun,

Zhao

2024

SummaryThis paper investigates the adaptive fuzzy backstepping control problem for uncertain discrete‐time nonlinear systems with mismatched disturbances. A novel adaptive fuzzy command filtered backstepping approach is proposed, which can overcome the noncausal problem by using the command filter. The filter errors generated by filter are removed by constructing error compensation mechanism. The fuzzy logic systems are used to approximate the uncertain nonlinear dynamics, and the unknown mismatched disturbances are actively attenuated by using adaptive control technique. Based on the proposed new weighed Lyapunov functions, all the signals in the close‐loop system are proved to be uniformly ultimately bounded. The viability of proposed method is demonstrated by simulation results.