Transactions of the Institute of Measurement and Control

Guan, Wei; Wang, Shuai; Chen, Zeren; Wang, Guoqiang; Huang, Tingting; Liu, Zhengbin; Guo, Jianbo

doi: 10.1177/01423312221136992pmid: N/A

The mobile crushing station is one of the main equipment of the semi-continuous open-pit mining system. The discharge arm and the receiving equipment are manually aligned, which has the problems of long alignment time and low alignment accuracy, which affects the working efficiency of the mining system. According to the development and application of space rendezvous and docking technology at home and abroad, the advantages and disadvantages of different measurement methods are compared and analysed, and the method of applying binocular measurement technology to system positioning in the automatic alignment system of the discharge arm is determined. There are three movements in the mechanical part of the designed discharge arm alignment control system, including the rotary motion of the visual measurement mechanism and the horizontal rotation and telescopic motion of the discharge arm. According to the kinematic analysis and binocular vision measurement theory, the deviation model of the alignment control of the discharge arm is established. A binocular vision measurement and localization method based on the combination of stereo calibration and template matching is proposed, which achieves surprising measurement accuracy. An automatic alignment method of the discharge arm of the mobile crushing station is proposed based on the binocular vision and fuzzy control method. Its validity is verified by simulation and experiment. The strategy of motion decomposition is applied to the alignment system to avoid unnecessary motion of the discharge arm. The research results all show that the alignment method can achieve the angle deviation within ±0.5 degrees, the distance deviation within ±15 mm, and the test alignment time is about 5 minutes, which is better than other alignment control models; the alignment accuracy and the alignment time are improved by more than 50%. The method can control the discharge arm to complete the alignment task quickly and smoothly, which lays a foundation for the further automatic research of the discharge arm.

Han, Bing; Jiang, Ju; Yu, Chaojun

doi: 10.1177/01423312221125967pmid: N/A

This paper addresses the resilient formation control problem for heterogeneous multiple unmanned aerial vehicles (multi-UAV) under false data injection (FDI) attacks and prescribed performance constraints. The case of both actuator and sensor attacks is considered simultaneously, and the multi-UAV can exchange the information through a directed communication network. A fuzzy adaptive observer (FAO) is first proposed to estimate the FDI attacks and the unmeasurable velocity information for each UAV. In order to transform the formation control of heterogeneous multi-UAV into a trajectory tracking control problem of individual UAVs, a bank of distributed estimators is designed to achieve the leader’s states by only using local information among neighboring UAVs. Then, by incorporating a novel tracking error transform method and fractional-order sliding mode control technique, a resilient prescribed performance tracking controller without velocity measurements is constructed. Furthermore, it is proved that all signals of the closed-loop formation control systems are uniformly ultimately bounded (UUB) stable under FDI attacks. Finally, the simulation results are given to verify the effectiveness and superiority of the proposed control strategy.

Liu, Suqi; Xu, Weimin

doi: 10.1177/01423312221122563pmid: N/A

In this paper, a model-free robust adaptive control scheme with finite-time convergence based on time-delay control is proposed for anti-sway and positioning control of two-dimensional underactuated overhead cranes. First, the whole overhead cranes system is simplified to an ultra-local model for time delay estimation (TDE). TDE brings a direct and effective model-free property but also an estimation error. Second, a sliding mode disturbance observer is designed to estimate and compensate for the TDE error. Third, sliding mode control (SMC) is used to enhance the robustness of the controller. An adaptive integral sliding surface is then designed to accelerate the sliding surface convergence rate and shorten the convergence time. To further optimize the selection of parameters, the parameter estimation is integrated to enhance the performance of model-free control. In the final analysis of the simulation, data yield that the introduction of parameter estimation increases the control performance by more than 20% on average, and the above facts verify the effectiveness of the scheme. Finally, the stability of the closed-loop control system is analyzed by using Lyapunov stability theory, and the effectiveness and robustness of the control scheme are verified through computer simulation results.

Wang, Ruihua; Li, Fupeng; Fei, Shumin

doi: 10.1177/01423312221124718pmid: N/A

This paper studies the finite-time issues (finite-time stability, finite-time boundedness, finite-time H∞ control) of discrete-time switched systems. Different from the existing Lyapunov function (LF) approaches only concerning activated subsystem, a novel approach for constructing LF is first proposed, which not only depends on the subsystem the switching reaches but also is closely related to the freshly inactive subsystem. Based on this, a transferring-dependent convex Lyapunov function (CLF) and a transferring-dependent LF are introduced, under which the improved finite-time stability results are deduced with admissible edge-dependent average dwell time (AED-ADT) technique. In light of the merits of established finite-time stability criteria, two transferring-dependent controllers are devised—that is, transferring-dependent convex controller (TD-CC) and transferring-dependent ordinary controller (TD-OC)—to perform finite-time control synthesis. Then, the finite-time H∞ control is further investigated based on the obtained control synthesis results. The designed transferring–dependent controllers can guarantee that the underlying system is finite-time bounded (FTB) with a prescribed H∞ performance under tighter AED-ADT switching signals. Besides, it is the first time to use the multiple convex Lyapunov function (MCLF) to investigate the finite-time issues. Finally, two numerical examples and a practical example are used to verify the effectiveness of the developed results.

Zhang, Fei; Cai, Mingjie; Wang, Baofang

doi: 10.1177/01423312221127146pmid: N/A

In this paper, a fast finite-time consensus protocol for multi-agent systems with nonholonomic constraints is studied. First, the chained form nonholonomic systems are transformed into two subsystems, which are the first-order subsystem and the reduced-order subsystem. Based on graph theory content and fast finite-time control theory, the fast finite-time consensus problems of the two subsystems are taken into consideration separately. Second, a switching control strategy is proposed to ensure that all states of multiple nonholonomic systems converge instantly to the same state in finite time. Finally, a numerical example is given to verify the effectiveness of the proposed control algorithm.

Zhang, Xiaoyi; Wu, Jie; Zhan, Xisheng; Han, Tao; Yan, Huaicheng

doi: 10.1177/01423312221125085pmid: N/A

In this paper, the time-varying formation tracking problem is addressed for a class of multi-agent systems, in which the input of followers is saturated and the input of the leader is unknown. Based on detectable state and undetectable state, a novel kind of protocols is proposed for solving time-varying formation tracking problem, without using any global information for the agents. Then, using the low-gain feedback approach and the Lyapunov stability theory, we can prove that the protocols steer the followers to accomplish and maintain the expected formation and track the leader under the appropriate assumptions. A numerical simulation is provided to verify the performance and effectiveness of our obtained main results.

He, Zhi-Ying; Chen, Chun-Jun; Yang, Lu; Wang, Dong-Wei

doi: 10.1177/01423312221126229pmid: N/A

When a high-speed train passes through tunnels, tunnel pressure waves will cause pressure fluctuation inside carriage. Traditional control strategy of shutting down air ducts for a fixed period may fail to consider both riding comfort and air quality. The similarity of tunnel pressure waves when the same train passes through the same tunnel provides a possibility to solve the problem by iterative learning control (ILC) algorithm. However, the varying amplitude and scale limit the application of conventional ILC. Thus in each iteration, the control inputs of the nearest condition in the historical database will be matched and applied to the control process, after which the control error will be gained and then the control inputs will be updated by the error. Next, the performance will be evaluated to refresh the database to make the control inputs in the database to be optimal. Feasibility analysis and simulations show the feasibility of controlling the fluctuation inside the carriage by matching the database records.

Jia, Mingxing; Leng, Chunyang

doi: 10.1177/01423312221126006pmid: N/A

In a rod pumping system, accurate prediction of dynamic liquid level is a key to rational optimization of pumping system parameters. At present, it is difficult to use a uniform prediction model for dynamic liquid-level prediction in different rod pumping systems. To this end, a method for predicting the dynamic liquid level of multiple wells in a pumping well based on dynamic and static information feature fusion (DSIFF) neural network is proposed in this paper. According to the principle of dynamic liquid-level calculation, suspension displacement, suspension load, pumping rod parameters, formation crude oil density, surface crude oil density, oil pressure, and casing pressure are used as inputs. The subnetwork feature extraction method is proposed for the problem of large network structure caused by the high dimension of the important dynamic data of suspension displacement and suspension load. The Huber loss function is used as the loss function of the prediction model for the case of abnormal data in the large amount of data required for model training. Finally, the results of comparative analysis show that the proposed method solves the problem of unified establishment of dynamic liquid-level prediction model for multiple oil wells and has better robustness for abnormal data.

Wu, Xia; Luo, Shibin; Wei, Caisheng; Qiu, Likuan

doi: 10.1177/01423312221124721pmid: N/A

The tracking control problem for a group of nonlinear lower-triangular systems with multiple uncertainties is investigated in this work. Wherein, a novel performance constraint is first constructed to guarantee the fixed-time convergence of the output tracking error. Subsequently, a linear extended high-gain observer is employed to estimate the system uncertainties including the unmeasured states and the external disturbances. Based on the observer estimations, a novel output-feedback tracking control approach is formulated via using the backstepping technique, to ensure the boundedness of the closed-loop system. Compared with the existing works, the primary advantages of the proposed design are that (1) the problem of "explosion of terms" is avoided by eliminating the need for the derivative of the virtual control signals and (2) without the use of extra auxiliary techniques, the fixed-time convergence can be guaranteed, where the convergence time is independent of the system states and initial conditions. Then, the results about system stability are proved by the theoretical analysis. Moreover, an extension of the proposed approach to multi-input multi-output systems is deduced in this paper to further present its versatility. Finally, two groups of numerical examples are performed to validate the effectiveness of the proposed controller.

Lin, Qiming; Zhou, Pingfang; Duan, Dengping

doi: 10.1177/01423312221124648pmid: N/A

This paper examines a finite-time command-filtered backstepping control proposed for a class of strict-feedback nonlinear systems with input delay and time-varying asymmetric full-state constraints. The existing control method either ignores the effect of input delay or converges asymptotically in infinite time. A command-filtered backstepping design is used to decrease computational burden. A first-order Levant differentiator is employed to replace the command filter for estimating the virtual control signals in finite time. The time-varying asymmetric barrier Lyapunov function (TVABLF) and command-filtered backstepping design are applied to alleviate the significant challenges caused by the backstepping approach and full-state constraints. A novel finite-time delay compensation mechanism is proposed to remove the impact of input delay. The closed-loop signals are proved to be practical bounded. Simulation results are provided to demonstrate the effectiveness of the proposed control scheme.