A segmented energy‐based nonlinear tracking control method for quadrotor transport system

2021 ◽  
Author(s):  
Juntong Qi ◽  
Yuan Ping ◽  
Mingming Wang ◽  
Chong Wu
Author(s):  
Lingfei Xiao

The multivariable robust tracking control problem for aeroengine is considered in this paper. On the basis of the aeroengine nonlinear affine uncertain dynamic model, and according to uncertainty and disturbance estimator (UDE) control approach, a novel aeroengine multivariable robust nonlinear tracking control method is presented in order to provide favorable tracking and disturbance rejection performance. After getting a generalization form of UDE-based aeroengine multivariable controller, a simplification form of control law is obtained when a specified form of low-pass filter is applied. Reference model of the aeroengine system should have satisfying dynamic, thus an optional reference model is provided. Simulation on a twin-shaft aeroengine with two inputs, verifies the effectiveness of the proposed method.


2021 ◽  
Author(s):  
Ping Sun ◽  
Shuoyu Wang ◽  
Rui Shan

Abstract This study discusses a finite-time tracking controller for a rehabilitative training walker that imposes velocity constraints. The walker was described using a stochastic model through which the rehabilitee mass can randomly change, and a velocity constraint method was proposed to control the velocity input to every omniwheel based on a model predictive algorithm. This approach is novel in that the velocity constraint information obtained from the kinematics model was used to design the tracking controller based on the stochastic dynamic model, thus successfully constraining the actual velocity of walker as per the stochastic system. The nonlinear tracking controller was built for the stochastic rehabilitative walker to make the system’s finite time stable. Also, simulation and experiment were performed, and results confirmed that the proposed tracking control method with velocity constraints is very effective, so it may enable various rehabilitees to train safely.


Author(s):  
Atsushi SAKAMOTO ◽  
Yuichi IKEDA ◽  
Isao YAMAGUCHI ◽  
Takashi KIDA

2021 ◽  
Vol 11 (13) ◽  
pp. 5865
Author(s):  
Muhammad Ahsan Gull ◽  
Mikkel Thoegersen ◽  
Stefan Hein Bengtson ◽  
Mostafa Mohammadi ◽  
Lotte N. S. Andreasen Struijk ◽  
...  

Wheelchair mounted upper limb exoskeletons offer an alternative way to support disabled individuals in their activities of daily living (ADL). Key challenges in exoskeleton technology include innovative mechanical design and implementation of a control method that can assure a safe and comfortable interaction between the human upper limb and exoskeleton. In this article, we present a mechanical design of a four degrees of freedom (DOF) wheelchair mounted upper limb exoskeleton. The design takes advantage of non-backdrivable mechanism that can hold the output position without energy consumption and provide assistance to the completely paralyzed users. Moreover, a PD-based trajectory tracking control is implemented to enhance the performance of human exoskeleton system for two different tasks. Preliminary results are provided to show the effectiveness and reliability of using the proposed design for physically disabled people.


Author(s):  
Qijia Yao

Space manipulator is considered as one of the most promising technologies for future space activities owing to its important role in various on-orbit serving missions. In this study, a robust finite-time tracking control method is proposed for the rapid and accurate trajectory tracking control of an attitude-controlled free-flying space manipulator in the presence of parametric uncertainties and external disturbances. First, a baseline finite-time tracking controller is designed to track the desired position of the space manipulator based on the homogeneous method. Then, a finite-time disturbance observer is designed to accurately estimate the lumped uncertainties. Finally, a robust finite-time tracking controller is developed by integrating the baseline finite-time tracking controller with the finite-time disturbance observer. Rigorous theoretical analysis for the global finite-time stability of the whole closed-loop system is provided. The proposed robust finite-time tracking controller has a relatively simple structure and can guarantee the position and velocity tracking errors converge to zero in finite time even subject to lumped uncertainties. To the best of the authors’ knowledge, there are really limited existing controllers can achieve such excellent performance under the same conditions. Numerical simulations illustrate the effectiveness and superiority of the proposed control method.


2020 ◽  
Vol 53 (2) ◽  
pp. 6151-6156
Author(s):  
Robert Schmid ◽  
Tony Srour ◽  
Johann Reger

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