Finite Time Convergence Guidance Law Accounting for Missile Autopilot

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Pingping Qu ◽  
Chuntao Shao ◽  
Di Zhou
Keyword(s):  
Finite Time ◽  
Control Method ◽  
Sliding Mode ◽  
Line Of Sight ◽  
Practical Applications ◽  
Maneuvering Target ◽  
Finite Time Convergence ◽  
Guidance Law ◽  
Convergence Control ◽  
Derivatives Of

A guidance law with finite time convergence is designed using the sliding mode control method and finite time convergence control theory, accounting for the missile autopilot as second-order dynamics. The high-order derivatives of the line of sight (LOS) angle are avoided in the expression of guidance law such that it can be implemented in practical applications. The designed guidance law is effective in compensating the bad influence of the autopilot dynamics on guidance accuracy. In simulations of intercepting a non maneuvering target or a maneuvering target, respectively, the designed guidance law is compared with the adaptive sliding mode guidance (ASMG) law in the presence of missile autopilot lag. Simulation results show that the designed guidance law is able to guide a missile to accurately intercept a nonmaneuvering target or a maneuvering target with finite time, even if it escapes in a great and fast maneuver and the autopilot has a relatively large lag.

scholarly journals Impact Time Guidance Law Considering Autopilot Dynamics Based on Variable Coefficients Strategy for Maneuvering Target

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Wei Shang ◽  
Jie Guo ◽  
Shengjing Tang ◽  
Yueyue Ma ◽  
Yao Zhang
Keyword(s):  
Finite Time ◽  
Sliding Mode ◽  
Variable Coefficients ◽  
Guidance System ◽  
Impact Time ◽  
Maneuvering Target ◽  
Guidance Law ◽  
Convergence Control ◽  
Unknown Disturbance ◽  
The Impact

This paper investigates the terminal guidance problem for the missile intercepting a maneuvering target with impact time constraint. An impact time guidance law based on finite time convergence control theory is developed regarding the target motion as an unknown disturbance. To further improve the performance of the guidance law, an autopilot dynamics which is considered as a first-order lag is taken into consideration. In the proposed method, the coefficients change with the relative distance between missile and target. This variable coefficient strategy ensures that the missile impacts the target at the desired time with little final miss distance. Then it is proved that states of the guidance system converge to sliding mode in finite time under the proposed guidance law. Numerical simulations are presented to demonstrate the effectiveness of the impact time guidance law with autopilot dynamics (ITGAD).

A New Finite Time Control Solution for Robotic Manipulators Based on Nonsingular Fast Terminal Sliding Variables and the Adaptive Super-Twisting Scheme

2019 ◽  
Vol 14 (3) ◽  
Author(s):  
Vo Anh Tuan ◽  
Hee-Jun Kang
Keyword(s):  
Finite Time ◽  
Control Method ◽  
Sliding Mode ◽  
Robotic Manipulators ◽  
Control Law ◽  
Continuous Control ◽  
Terminal Sliding Mode ◽  
Finite Time Convergence ◽  
Position Errors ◽  
Time Control

In this study, a new finite time control method is suggested for robotic manipulators based on nonsingular fast terminal sliding variables and the adaptive super-twisting method. First, to avoid the singularity drawback and achieve the finite time convergence of positional errors with a fast transient response rate, nonsingular fast terminal sliding variables are constructed in the position errors' state space. Next, adaptive tuning laws based on the super-twisting scheme are presented for the switching control law of terminal sliding mode control (TSMC) so that a continuous control law is extended to reject the effects of chattering behavior. Finally, a new finite time control method ensures that sliding motion will take place, regardless of the effects of the perturbations and uncertainties on the robot system. Accordingly, the stabilization and robustness of the suggested control system can be guaranteed with high-precision performance. The robustness issue and the finite time convergence of the suggested system are totally confirmed by the Lyapunov stability principle. In simulation studies, the experimental results exhibit the effectiveness and viability of our proposed scheme for joint position tracking control of a 3DOF PUMA560 robot.

A finite-time-convergent composite guidance law with strong fault-tolerant performance

2018 ◽  
Vol 233 (9) ◽  
pp. 3120-3130 ◽  
Author(s):  
Feng Chen ◽  
Guangjun He ◽  
Qifang He
Keyword(s):  
Finite Time ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Angular Rate ◽  
Gain Coefficient ◽  
High Gain ◽  
Line Of Sight ◽  
Practical Implementation ◽  
Integral Sliding Mode ◽  
Guidance Law

To improve the performance of tracking and intercepting the low-altitude target, a nonlinear integral sliding mode guidance law is designed firstly, which can guarantee that the line-of-sight angle converges to a desired tracking angle and the line-of-sight angular rate converges to zero in finite time. Meanwhile, to solve the chattering problem caused by the high gain coefficient of the sign function in the guidance law, a sliding mode disturbance observer is designed to estimate the maneuvering acceleration of the target. Moreover, a composite nonlinear integral sliding mode guidance law is designed by introducing the estimated value of the acceleration, which can weaken the chattering phenomenon effectively. Finally, considering the magnitude loss fault of the guidance command that may occur in the practical implementation, a composite guidance law with strong fault-tolerant performance is designed by introducing a fault compensation command, which can effectively improve the reliability of the system.

A Guidance Law With Terminal Impact Angle Constraint Accounting for Missile Autopilot

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
Di Zhou ◽  
Pingping Qu ◽  
Sheng Sun
Keyword(s):  
Control Method ◽  
Sliding Mode ◽  
Dynamic Surface Control ◽  
Impact Angle ◽  
Second Order ◽  
Dynamic Surface ◽  
Practical Applications ◽  
Guidance Law ◽  
Low Pass ◽  
Impact Angle Constraint

A sliding-mode guidance (SMG) law is designed to intercept maneuvering targets with impact angle constrained flight trajectories under the assumption of ideal missile autopilot. Furthermore, accounting for the autopilot as second-order dynamics, a new guidance law with terminal impact angle constraint is designed using the dynamic surface control method. Some first-order low-pass filters are introduced into the designing process to avoid the occurrence of high-order derivatives of the line of sight (LOS) angle in the expression of the guidance law such that the guidance law can be implemented in practical applications. The proposed guidance law is effective in compensating for the second-order autopilot lag. Simulation results show that it is able to guide a missile to impact a maneuvering target with a desired angle and a small miss distance.

Cooperative near-space interceptor mid-course guidance law with terminal handover constraints

2018 ◽  
Vol 233 (6) ◽  
pp. 1960-1976 ◽  
Author(s):  
Haoqiang Zhang ◽  
Shengjing Tang ◽  
Jie Guo
Keyword(s):  
Boundary Value Problem ◽  
Finite Time ◽  
Sliding Mode ◽  
Initial Conditions ◽  
Boundary Value ◽  
Programming Method ◽  
Line Of Sight ◽  
Point Boundary ◽  
Guidance Law ◽  
Bounded Perturbation

A cooperative problem in mid-course guidance phase is addressed in this paper. For providing suitable initial conditions of successful terminal salvo attack, a novel finite-time cooperative mid-course guidance law with terminal handover constraints is proposed. Firstly, a three-dimensional guidance model of mid-course is decoupled in a planar line-of-sight frame as a two-point boundary value problem. The terminal handover constraints which can guarantee an ideal zero effort terminal engagement are proposed and analyzed. Secondly, the design of the cooperative mid-course guidance law is separated into two stages. The acceleration commands along the line-of-sight direction are developed based on the finite-time average-consensus protocol and super-twisting algorithm in the first stage. In the second stage, the model predictive static programming method is adopted to solve the two-point boundary value problem in line-of-sight frame with a known final time from first stage. Furthermore, sliding mode control theory is used in combination with model predictive static programming method to satisfy terminal handover constraints with bounded perturbation. Finally, numerical simulations of two four-interceptor cooperative scenario are carried out to verify the validity of the proposed cooperative guidance law. The simulation results reflect that all the four interceptors can reach their own predictive interception points with specific approach angles simultaneously.

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