The prescribed time sliding mode control for attitude tracking of spacecraft

Abstract

With the development of the space missions, there are extensive missions in the demand of the prescribed time convergence. However, it's still a difficult work to combine the prescribed time method with the sliding mode control due to the infinite gain of the prescribed time method while approaching the prescribed time and two periods of sliding mode control. In this paper, a new prescribed time sliding mode control method is proposed for general systems with matched disturbances, from the second-order system to the high-order system. A novel sliding mode variable with explicit time term is designed for achieving the prescribed time convergence. More importantly, as time approaches the prescribed time, the singularity of control input can be avoided. Finally, this paper presents a disturbance observer based prescribed time sliding mode control method for attitude tracking of spacecraft and the efficiency of this method has been verified through the numerical simulations.

Continuous Prescribed-Time Sliding Mode Control with A Prescribed-Time ESO for Second-Order Nonlinear Systems with Mismatched Disturbance

“…where G i1 and G i2 are bounded numbers, of which the detailed form is easily accessible through Eqs. ( 28)- (30) and omitted here for brevity. Recalling µ = µ 1 3+ν and ν > 0, it is clear that the observation errors (x 1 , x2 , x3 ) are driven to zero as t → t 0 + T .…”

“…Z Chen developed a time-varying PTSMC for the attitude tracking of spacecraft [30]. However, the PTSMC laws in [27][28][29][30] are discontinuous. Consequently, severe chattering may occur, considering the finite sampling frequency of practical applications.…”

“…Accordingly, a CPTSMC is derived based on the novel convergent form, enabling the UBST of system states prescribed by only one parameter. Chattering is alleviated compared to the PTSMC [15][16][17][18][27][28][29][30], and conservativeness in meeting temporal demands is reduced compared to the PTSMC in [15][16][17][18]. Moreover, the boundedness of all system signals has been verified.…”

“…Lei Cui et al derived a time-varying PTSMC for partial integrated guidance and control [29]. Z Chen developed a time-varying PTSMC for the attitude tracking of spacecraft [30]. However, the PTSMC laws in [27][28][29][30] are discontinuous.…”

“…Most importantly, although there exist some timevarying prescribed-time control methods for the highorder integrator systems [19], p-norm nonlinear systems [21], and strict-feedback-like nonlinear systems [23], the research [19][20][21][22][23][24][25][26][27][28][29][30] has not coped with nonlinear systems with mismatched state-independent disturbance, which are commonly encountered in practice, such as hypersonic vehicles [31], vertical take-off and landing reusable launch vehicles [32], active suspension systems [33], and DC motor servos [34,35]. Considering the fast convergence demands and the existence of mismatched stateindependent disturbances, designing a novel CPTSMC with little conservativeness for temporal demands is both meaningful and challenging.…”