Application of Super Twisting Guidance Law Based on Extended State Observer

2013 ◽  
Vol 433-435 ◽  
pp. 1009-1014 ◽  
Author(s):  
Yang Chong ◽  
Ke Zhang

In order to intercept high maneuvering target, a super twisting guidance law based on extended state observer (ESO) is proposed. The target acceleration can be defined as external disturbance which can be estimated in ESO and compensated in super twisting guidance law. The super twisting algorithm can effectively decrease the undesired charting which exists in normal sliding mode control. The simulation results which are verified via computer show that this guidance law has strong robustness, target acceleration can be estimated and compensated, and has good miss distance.

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Ouxun Li ◽  
Ju Jiang ◽  
Li Deng ◽  
Shutong Huang

Aiming at the uncertainty and external disturbance sensitivity of the near space vehicles (NSV), a novel sliding mode controller based on the high-order linear extended state observer (LESO) is designed in this paper. In the proposed sliding mode controller, the double power reaching law is adopted to enhance the state convergence rate, and the high-order LESO is designed to improve the antidisturbance ability. Moreover, the appropriate observer bandwidth and extended order are selected to further reduce or even eliminate the disturbance by analyzing their influences on the observer performance. Finally, the simulation demonstrations are given for the NSV control system with uncertain parameters and external disturbances. The theoretical analyses and simulation results consistently indicate that the proposed high-order LESO with carefully selected extended order and observer bandwidth has better performance than the traditional ones for the nonlinear NSV system with parametric uncertainty and external disturbance.


Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3305 ◽  
Author(s):  
Gang Wang ◽  
Chenghui Zhou ◽  
Yu Yu ◽  
Xiaoping Liu

When the wheeled mobile robot (WMR) is required to perform specific tasks in complex environment, i.e., on the forestry, wet, icy ground or on the sharp corner, wheel skidding and slipping inevitably occur during trajectory tracking. To improve the trajectory tracking performance of WMR under unknown skidding and slipping condition, an adaptive sliding mode controller (ASMC) design approach based on the extended state observer (ESO) is presented. The skidding and slipping is regarded as external disturbance. In this paper, the ESO is introduced to estimate the lumped disturbance containing the unknown skidding and slipping, parameter variation, parameter uncertainties, etc. By designing a sliding surface based on the disturbance estimation, an adaptive sliding mode tracking control strategy is developed to attenuate the lumped disturbance. Simulation results show that higher precision tracking and better disturbance rejection of ESO-ASMC is realized for linear and circular trajectory than the ASMC scheme. Besides, experimental results indicate the ESO-ASMC scheme is feasible and effective. Therefore, ESO-ASMC scheme can enhance the energy efficiency for the differentially driven WMR under unknown skidding and slipping condition.


2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Zhijun Chen ◽  
Yong Zhao ◽  
Yuzhu Bai ◽  
Dechao Ran ◽  
Liang He

This paper presents a robust controller with an extended state observer to solve the Synchronous Fly-Around problem of a chaser spacecraft approaching a tumbling target in the presence of unknown uncertainty and bounded external disturbance. The rotational motion and time-varying docking trajectory of tumbling target are given in advance and referred as the desired tracking objective. Based on dual quaternion framework, a six-degree-of-freedom coupled relative motion between two spacecrafts is modeled, in which the coupling effect, model uncertainties, and external disturbances are considered. More specially, a novel nonsingular terminal sliding mode is designed to ensure the convergence to the desired trajectory in finite time. Based on the second-order sliding mode, an extended state observer is employed to the controller to compensate the closed-loop system. By theoretical analysis, it is proved that the modified extended-state-observer-based controller guarantees the finite-time stabilization. Numerical simulations are taken to show the effectiveness and superiority of the proposed control scheme. Finally, Synchronous Fly-Around maneuvers can be accomplished with fast response and high accuracy.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Yulin Wang ◽  
Shengjing Tang ◽  
Wei Shang ◽  
Jie Guo

Terminal guidance law for missiles intercepting high maneuvering targets considering the limited available acceleration and autopilot dynamics of interceptor is investigated. Conventional guidance laws based on adaptive sliding mode control theory were designed to intercept a maneuvering target. However, they demand a large acceleration for interceptor at the end of the terminal guidance, which may have acceleration saturation especially when the target acceleration is close to the available acceleration of interceptor. In this paper, a terminal guidance law considering the available acceleration and autopilot dynamics of interceptor is proposed. Then, a fuzzy system is utilized to approximate and replace the variable structure term, which can handle the unknown target acceleration. And an adaptive neural network system is adopted to compensate the effects caused by the designed overlarge acceleration of interceptor such that the interceptor with small available acceleration can intercept the high maneuvering target. Simulation results show that the guidance law with available acceleration and autopilot dynamics (AAADG) is highly effective for reducing the acceleration command and achieving a small final miss distance.


2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Zhenlei CHEN ◽  
Qing GUO ◽  
Yao YAN ◽  
Dan JIANG

For the 2- Degree of Freedom (DOF) lower limb exoskeleton, to ensure the system robustness and dynamic performance, a linear-extended-state-observer-based (LESO) robust sliding mode control is proposed to not only reduce the influence of parametric uncertainties, unmodeled dynamics, and external disturbance but also estimate the unmeasurable real-time joint angular velocity directly. Then, via Lyapunov technology, the stability of the corresponding LESO and controller is proven. The appropriate and reasonable simulation was carried out to verify the effectiveness of the proposed LESO and exoskeleton controller.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Yongfu Li ◽  
Bin Yang ◽  
Taixiong Zheng ◽  
Yinguo Li

Considering the high accuracy requirement of information exchange via vehicle-to-vehicle (V2V) communications, an extended state observer (ESO) is designed to estimate the opening angle change of an electronic throttle (ET), wherein the emphasis is placed on the nonlinear uncertainties of stick-slip friction and spring in the system as well as the existence of external disturbance. In addition, a back-stepping sliding mode controller incorporating an adaptive control law is presented, and the stability and robustness of the system are analyzed using Lyapunov technique. Finally, numerical experiments are conducted using simulation. The results show that, compared with back-stepping control (BSC), the proposed controller achieves superior performance in terms of the steady-state error and rising time.


2021 ◽  
Vol 18 (3) ◽  
pp. 172988142110110
Author(s):  
Mingcong Li ◽  
Chen Guo ◽  
Haomiao Yu

This article focuses on the problem of path following for underactuated unmanned surface vehicles (USVs) considering model uncertainties and time-varying ocean currents. An extended state observer (ESO)-based integral line-of-sight (ILOS) with an integral sliding mode adaptive fuzzy control scheme is proposed as the main control framework. First, a novel ESO is employed to estimate the surge and sway velocities based on the kinetic model, which are difficult to measure directly. Then, the adaptive ILOS guidance law is proposed, in which the integral vector is incorporated into the adaptive method to estimate the current velocities. Meanwhile, an improved fuzzy algorithm is introduced to optimize the look-ahead distance. Second, the controller is extended to deal with the USV yaw and surge velocity signal tracking using the integral sliding mode technique. The uncertainties of the USV are approximated via the adaptive fuzzy method, and an auxiliary dynamic system is presented to solve the problem of actuator saturation. Then, it is proved that all of the error signals in the closed-loop control system are uniformly ultimately bounded. Finally, a comparative simulation substantiates the availability and superiority of the proposed method for ESO-based ILOS path following of USV.


Author(s):  
Xiaojian Zhang ◽  
Mingyong Liu ◽  
Yang Li ◽  
Feihu Zhang

This paper discusses the issue of impact angle control over guidance in scenarios of an interceptor against the maneuvering targets. Inspired by switched nonlinear system, an integral sliding mode manifold is first developed. Then, the impact angle control over guidance is derived by using the integral sliding mode manifold with finite time control. To obtain precise guidance effect, the second-order of extended state observer is proposed in the case of unknown target acceleration. Finally, composited impact angle control over guidance based on extended state observer is developed. The stability analysis of the proposed guidance law is demonstrated by using Lyapunov function, and theoretical proof that the line-of-sight angle and line-of-sight angular rate can converge to the desired value in finite steps, respectively. Numerical simulation results are illustrated to validate the performance of the proposed guidance law.


Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Shengnan Gao ◽  
Zhouhua Peng ◽  
Dan Wang ◽  
Lu Liu

This paper is concerned with the target tracking problem of an autonomous surface vehicle in the presence of a maneuvering target. The velocity information of target is totally unknown to the follower vehicle, and only the relative distance and angle between the target and follower are obtained. First, a reduced-order extended state observer is used to estimate the unknown relative dynamics due to the unavailable velocity of the target. Based on the reduced-order extended state observer, an antidisturbance guidance law for target tracking is designed. The input-to-state stability of the closed-loop target tracking guidance system is analyzed via cascade theory. Furthermore, the above result is extended to the case that collisions between the target and leader are avoided during tracking, and a collision-free target tracking guidance law is developed. The main feature of the proposed guidance law is twofold. First, the target tracking can be achieved without using the velocity information of the target. Second, collision avoidance can be achieved during target tracking. Simulation results show the effectiveness of the proposed antidisturbance guidance law for tracking a maneuvering target with the arbitrary bounded velocity.


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