Mode Variable Structure Control Theory Research Articles

Path Planning and Tracking Control of Tracked Agricultural Machinery Based on Improved A* and Fuzzy Control

In order to improve the efficiency of agricultural machinery operations and reduce production costs, this article proposes a path planning algorithm based on the improved A* algorithm (IA*) and a tracking controller based on fuzzy sliding mode variable structure control (F-SMC) to meet the operation requirements of tracked agricultural machinery. Firstly, we introduce a heuristic function with variable weights, a penalty, and a fifth-order Bezier curve to make the generated path smoother. On this basis, the ant colony algorithm is introduced to further optimize the obtained path. Subsequently, based on fuzzy control theory and sliding mode variable structure control theory, we established a kinematic model for tracked agricultural machinery as the control object, designed a fuzzy sliding mode approaching law, and preprocessed it to reduce the time required for sliding mode control to reach the chosen stage. The simulation experiment of path planning shows that compared with A*, the average reduction rate of the path length for IA* is 5.51%, and the average reduction rate of the number of turning points is 39.01%. The path tracking simulation experiment shows that when the driving speed is set to 0.2 m/s, the adjustment time of the F-SMC controller is reduced by 0.99 s and 1.42 s compared to the FUZZY controller and PID controller, respectively. The variance analysis of the adjustment angle shows that the minimum variance of the F-SMC controller is 0.086, and the error converges to 0, proving that the vehicle trajectory is smoother and ultimately achieves path tracking. The field test results indicate that the path generated by the IA* algorithm can be tracked by the F-SMC controller in the actual environment. Compared to the A* algorithm and FUZZY controller, the path tracking time reduction rate of IA* and F-SMC is 29.34%, and the fuel consumption rate is reduced by 2.75%. This study is aimed at providing a feasible approach for improving the efficiency of tracked agricultural machinery operations, reducing emissions and operating costs.

Research on Lateral and Longitudinal Coordinated Control of Distributed Driven Driverless Formula Racing Car under High-Speed Tracking Conditions

Aiming at the problem that it is difficult to ensure the trajectory tracking accuracy and driving stability of the distributed driven driverless formula racing car under high-speed tracking conditions, a lateral and longitudinal coordinated control strategy is proposed. Based on the adaptive model predictive control theory, the lateral motion controller is designed, and the prediction time domain of the controller is changed in real time according to the change of vehicle speed. Based on the sliding mode variable structure control theory, a longitudinal motion controller is designed to accurately track the desired vehicle speed. Considering the coupling between the lateral and longitudinal controls, the lateral controller inputs the longitudinal speed and displacement of the vehicle, using the feedback mechanism to update the prediction model in real time, the longitudinal controller takes the front wheel angle as the input, the driving torque is redistributed through the differential drive control, and the lateral and longitudinal coordinated control is carried out to improve the trajectory tracking accuracy and driving stability. The typical working conditions are selected for co-simulation test verification. The results show that the lateral and longitudinal coordinated control strategy can effectively improve the vehicle trajectory tracking control accuracy and driving stability.

Sliding Mode Variable Structure Chaos Control for Propulsion Motor of Deep Sea Robot

As the deepwater robot’s dynamic thruster system, the brushless thruster system’s performance will influence the whole system reliability, stabilization, safety. The brushless thruster system will appear chaotic phenomena when its system structure and parameter match badly. The phenomena will lead the deepwater robot out of control, even involved by ocean wave. Aiming the chaos phenomenon of propulsion motor of deepwater robot, this paper proposes the application of sliding mode variable structure control theory to chaos control. The sliding mode variable structure chaotic control of brushless propulsion motor for deep-sea robot is designed, and the controller is designed. The feasibility and effectiveness of the chaotic control are simulated, analyzed and verified. The research result proves that, the gradation sliding mode variable structure using in control of the deepwater robot thruster motor chaotic motion are feasible and effective, i.e. the thruster motor can research the stabilization state from chaotic state and the procedure of control is related to the controller structure, parameter, and control time. And for the example system, the exponent gradation sliding mode variable stature control effect is the better.

Cooperative control method of multi-missile formation under uncontrollable speed

Under the missile speed is uncontrollable, a design method of multi-missile formation flight controller based on the sliding mode variable structure control theory and adaptive dynamic surface control theory is proposed. Firstly, according to the relative position of the leader and the follower in the inertial frame, the tracking error model for the relative position and the expected relative position between the leader and the follower is obtained, and the multi-missile formation control system in the inertial coordinate system is obtained. Secondly, in order to obtain the expression of the formation control system in the ballistic coordinate system, the acceleration of the missile in the ballistic coordinate system is converted to the inertial coordinate system. Combining with the tracking of the relative position and the desired relative position of the leader and the followers, we can obtain the simplified error model for the formation control system. Then the sliding mode variable structure control theory and the adaptive dynamic surface control theory are used to design the formation controllers for the leader and follower missiles respectively, and the stability of the present controller is analysed via the Lyapunov stability theory. Finally, the designed formation controllers are used for the leader and follower missiles to simulate the parameters. The results verify the feasibility and effectiveness of the present method.

Design of Quad-rotor Controller Based on Fractional Order Sliding Mode Control

According to the chattering problems of traditional sliding mode index exponential reaching law, this paper proposes a fractional order sliding mode index exponential reaching law control strategy, which is applied to the quad-rotor helicopter attitude control. Combined the theory of fractional order calculus and sliding mode variable structure control theory, the fractional order sliding mode controller is designed. The method of lyapunov analysis proves that this controller can make the system asymptotically stable. Simulation and experiments show that the proposed fractional order sliding mode control system not only undermines the chattering of traditional sliding mode exponential reaching law but also reduces the adjusting time and control margin of the system.

A Novel Cooperative Control System of Multi-Missile Formation Under Uncontrollable Speed

This article investigates a novel cooperative control system based on the sliding mode variable structure control theory for multi-missile formation flight. It is desired in practice to form and maintain the formation under the premise of uncontrollable missile speed. First, under the inertial coordinate system, we obtain the model of the formation control problem using the relative position of the leader to the follower. Then, we perform acceleration conversion and combine it to this model, getting the form of the formation problem model in the ballistic coordinate system. The finished model is useful for researchers to design the formation controller on this basis. Besides, the sliding mode variable structure control theory is used to design the formation controller for the system not considering disturbances and considering disturbances. Then we use the Lyapunov stability theory to analyze the stability of the formation control system. Finally, we compare our method with another method which requires controllable speed. According to numerical simulations, the method proposed in this article can achieve similar relative position errors under the condition of uncontrollable speed. And the robustness, versatility and formation adaptability of the method we propose are confirmed by simulation results.

Control Strategy of the Vehicle's Active Steer by Wire

Zhang, Q.; Lin, W.; Wang, Y.; Wu, X., and Luo, Y., 2020. Control strategy of the vehicle's active steer by wire. In: Yang, Y.; Mi, C.; Zhao, L., and Lam, S. (eds.), Global Topics and New Trends in Coastal Research: Port, Coastal and Ocean Engineering. Journal of Coastal Research, Special Issue No. 103, pp. 355–360. Coconut Creek (Florida), ISSN 0749-0208.The Steer-By-Wire (SBW) system is free from the constraints of mechanical structure. Whether the system can work normally depends on the correctness of the control strategy. Therefore, this paper will study the control strategy of active steering by wire, which includes the design of ideal variable angle ratio control and active front wheel steering controller. Feed-forward control of ideal variable angle transmission ratio was determined based on constant yaw angular velocity gain. The sliding mode variable structure control theory is adopted. Based on the yaw rate deviation, the integral sliding surface is constructed, and the control strategy of equivalent and switching control is designed and active front wheel steering controller is completed. Through feedback control, the active control of the vehicle's front wheel angle is achieved, which improves the stability of the vehicle. Finally, through the typical test conditions, the designed control strategy was simulated and verified, and compared with the simulation results of uncontrolled vehicles. The results showed that the sliding mode controller of active SBW front wheel designed by yaw angular velocity feedback under the ideal variable transmission ratio can run stably under any working conditions and achieve good track following ability.

Industrial Grade Adaptive Control Scheme for a Micro-Grid Integrated Dual Active Bridge Driven Battery Storage System

In this paper, an industrial grade adaptive control scheme is proposed for a micro-grid integrated dual active bridge driven battery management system (DIBMS). A benchmark industrial grade adaptive control scheme depends on two factors namely robustness and computational resource utilization when such controllers are implemented over processors. The mathematical model of DIBMS system is nonlinear, thus for desired response, non-linear controllers based on sliding mode variable structure control theory suits it well for the state regulation problem of DIBMS, however such controllers utilize high computational resources when practically implemented over processors. Keeping in view the above performance indices, this paper proposes an industrial grade computationally efficient and finite time adaptive robust convergent control for DIBMS system. A proportional integral (PI) scheme is used as central control unit and Hebbian algorithm with double integration of the state error is introduced for online tuning the gains of central control unit. The robustness and computational resource efficiency of the proposed control paradigm is validated using a laboratory scale test bench through TI Launchpad (TMS320F28379D). The superiority of the proposed AI based PI control paradigm is compared with classical PI, integer order sliding mode control (SMC), and fractional order SMC (FOSMC) in terms of computational resource utilization and robustness under all test conditions.

The Research on Sensorless Control of Permanent Magnet Synchronous using SMC and SMO

This work proposes a way to achieve the sensorless control of permanent-magnet synchronous motor using sliding mode controller (SMC) and Sliding Mode Observer(SMO). In this Paper, the SMC is designed to replace the speed control loop PI controller from the original permanent magnet synchronous motor control system with the sliding mode variable structure control theory. Combined with the modified SMO, the “SMC and modified SMO” motor control system is proposed. Compared with the “PI and modified SMO” mode, the performance of the motor control is increased substantially, the interference torque speed attenuation is decreased by 87.5%, and the speed control error was also reduced by 67.7%. There is no overshoot with the reaction speed, and significant improvement in response speed, anti-interference performance, control accuracy and observation precision are achieved. Overall, both the system control and observation performance are significantly improved.

Research on Simulation and Analysis of Monitoring Process of Hail-proof Apple Bagging Four-rotor Aircraft

This bagging method is feasible and can produce strong economic and social benefits, and is recognized by the majority of fruit farmers. With the frequent occurrence of natural disasters in recent years, search and rescue equipment of four-rotor aircraft has been widely used. Firstly, the overall design architecture of the four-rotor flight system is introduced. Then the dynamic model of the four-axis aircraft is established for the ground coordinate system and the collective coordinate system. At the same time, the response speed, control stability, and robustness are obtained. The control algorithm of aircraft is designed by using sliding mode variable structure control theory. Finally, the simulation data is used to compare the controller with the controller, and it is proved that the controller’s strength and stability meet the requirements of the project.

Terminal Sliding Mode Tracking Controller Design for Automatic Guided Vehicle

Based on sliding mode variable structure control theory, the path tracking problem of automatic guided vehicle is studied, proposed a controller design method based on the terminal sliding mode. First of all, through analyzing the characteristics of the automatic guided vehicle movement, the kinematics model is presented. Then to improve the traditional expression of terminal sliding mode, design a nonlinear sliding mode which the convergence speed is faster than the former, verified by theoretical analysis, the design of sliding mode is steady and fast convergence in the limited time. Finally combining Lyapunov method to design the tracking control law of automatic guided vehicle, the controller can make the automatic guided vehicle track the desired trajectory in the global sense as well as in finite time. The simulation results verify the correctness and effectiveness of the control law.

Design of Nonlinear Robust Damping Controller for Power Oscillations Suppressing Based on Backstepping-Fractional Order Sliding Mode

In this paper, a novel nonlinear robust damping controller is proposed to suppress power oscillation in interconnected power systems. The proposed power oscillation damping controller exhibits good nonlinearity and robustness. It can consider the strong nonlinearity of power oscillation and uncertainty of its model. First, through differential homeomorphic mapping, a mathematical model of the system can be transformed into the Brunovsky standard. Next, an extended state observer (ESO) estimated and compensated for model errors and external disturbances as well as uncertain factors to achieve dynamic linearization of the nonlinear model. A power oscillation damping controller for interconnected power systems was designed on a backstepping-fractional order sliding mode variable structure control theory (BFSMC). Compared with traditional methods, the controller exhibits good dynamic performance and strong robustness. Simulations involving a four-generator two-area and partial test system of Northeast China were conducted under various disturbances to prove the effectiveness and robustness of the proposed damping control method.

The research of digital-PID and sliding mode control strategy for DC/DC converter

Based on the fixed frequency PWM control strategy, this paper introduces a DSP-based digital PID control technology and a sliding mode variable structure control theory for high frequency DC/DC converter in detail. Firstly, a traditional analogy sliding mode controller with the reaching law and a digital PID controller are designed, respectively. Then, experimental prototypes for two kinds of control systems for DC/DC converters are constructed, and comparative experiment are implemented. The experiment results show that the DC/DC converter by using digital PID controller has a fast dynamic response and high accuracy in the presence of the input voltage fluctuation and load variation.

The research of digital-PID and sliding mode control strategy for DC/DC converter

Based on the fixed frequency PWM control strategy, this paper introduces a DSP-based digital PID control technology and a sliding mode variable structure control theory for high frequency DC/DC converter in detail. Firstly, a traditional analogy sliding mode controller with the reaching law and a digital PID controller are designed, respectively. Then, experimental prototypes for two kinds of control systems for DC/DC converters are constructed, and comparative experiment are implemented. The experiment results show that the DC/DC converter by using digital PID controller has a fast dynamic response and high accuracy in the presence of the input voltage fluctuation and load variation.

A Speed Control Method for Underwater Vehicle under Hydraulic Flexible Traction

Underwater vehicle speed control methodology method is the focus of research in this study. Driven by a hydraulic flexible traction system, the underwater vehicle advances steadily on underwater guide rails, simulating an underwater environment for the carried device. Considering the influence of steel rope viscoelasticity and the control system traction structure feature, a mathematical model of the underwater vehicle driven by hydraulic flexible traction system is established. A speed control strategy is then proposed based on the sliding mode variable structure of fuzzy reaching law, according to nonlinearity and external variable load of the vehicle speed control system. Sliding mode variable structure control theory for the nonlinear system allows an improved control effect for movements in “sliding mode” when compared with conventional control. The fuzzy control theory is also introduced, weakening output chattering caused by the sliding mode control switchover while producing high output stability. Matlab mathematical simulation and practical test verification indicate the speed control method as effective in obtaining accurate control results, thus inferring strong practical significance for engineering applications.

Research of Waste Heat Power Generation Main Steam Valve Control

In order to improve the stability of steam turbine under large disturbance, the controller of cement waste heat power generation valve was designed by using exponential terminal sliding mode variable structure control method. In this paper, taking a single machine infinite bus power system as an example, established mathematical model of waste heat generator valve system, and designed the valve controller of synchronous generator based on the exponential terminal sliding mode variable structure control theory. Then, valve control simulation model was set up and simulation experiment was performed by MATLAB. Finally, verify the effectiveness of the scheme by comparison analysis. Simulation results show that the controller can effectively improve the transient stability of power system and the dynamic quality.

Design of Nonlinear Robust Rotor Current Controller for DFIG Based on Terminal Sliding Mode Control and Extended State Observer

As to strong nonlinearity of doubly fed induction generators (DFIG) and uncertainty of its model, a novel rotor current controller with nonlinearity and robustness is proposed to enhance fault ride-though (FRT) capacities of grid-connected DFIG. Firstly, the model error, external disturbances, and the uncertain factors were estimated by constructing extended state observer (ESO) so as to achieve linearization model, which is compensated dynamically from nonlinear model. And then rotor current controller of DFIG is designed by using terminal sliding mode variable structure control theory (TSMC). The controller has superior dynamic performance and strong robustness. The simulation results show that the proposed control approach is effective.

Stability Control for Dual-Motor Independent Drive Electric Vehicle Based on Sliding Mode Control

Two motors of Dual-Motor Independent Drive Electric Vehicle can be controlled independently, which can enrich the method of stability control for vehicle. In order to fully take use of the advantage，The man-vehicle system with eight degrees of freedom ,which includes Magic Formula tire model and driver model based on Preview Follower Theory, was set up by using MATLAB/SIMULINK. Considering the complexity of the driving condition and the nonlinear time-varying characteristics of the vehicle systems, a controller based on Sliding mode variable structure control theory was set up, which selected Yaw rate as Control variable and two motors as actuators. The simulation results show that handling and stability of vehicle can be improved greatly by the Sliding mode controller.

Research on pose optimal sliding mode control method for six DOF air-bearing spacecraft simulator

According to the requirements of the third phase project of Chinas lunar probe program, a six degrees of freedom (DOF) air-bearing spacecraft simulator was designed for the lunar orbiter docking with the sample transfer performance test system. A pose optimal sliding mode control strategy was proposed for the pose control of air-bearing table, which integrates sliding mode variable structure control and optimal control theory, through integral compensation term to enhance robustness of the optimal regulator, eliminate the approaching modal of sliding mode control, and solve the impact of large load inertia ratio and uncertainty factors of air-bearing pose control system on the control accuracy. Experimental results indicate that the control precision of the system meets the task requirements, and validate the correctness and feasibility of the scheme.

Research and Analysis for Electronic Throttle Control Method

By reviewing the development of the electronic throttle abroad, it introduces the development of foreign electronic throttle. Control theory has been constantly enriched and control functions developed from single integrated. With the development of domestic research, some car manufacturing companies and university research institutions have obtained certain results. Articles in control theory focus on the theory of PID control, fuzzy control theory, sliding mode variable structure control theory research and more mature theory, and then, the above theories were compared. Finally, according to the articles of the current development state of electronic throttle, the article describes the prospect of the electronic throttle.