Stability Of Control Method Research Articles

Stability Analysis of Surrounding Rock of Large Section Ultradeep Shaft Wall

In order to study the stability of deep surrounding rock during the excavation of new main shaft in Xincheng gold mine, a construction method suitable for large section ultradeep shaft is proposed. A series of analyses were carried out in this study, including the in situ stress test, stress response of surrounding rock disturbance, deformation and failure characteristics, and numerical simulation. Based on the above analysis, the stability control method of surrounding rock in the process of deep excavation of the new main shaft is proposed. The results show that (1) the maximum principal stress of deep surrounding rock of new main shaft is horizontal stress, and the surrounding rock of the shaft has strong rock burst tendency after excavation; (2) the influence range of the deep shaft excavation disturbance is 6.4 times the shaft radius, in which the temporary support should be strengthened to avoid the influence of excavation disturbance on the stability of shaft wall rock; (3) the failure shape of surrounding rock of the deep shaft excavation was “ear” failure, and the failure depth was not more than 2.5 m; (4) after replacing the original “one‐excavation and one‐masonry” construction with “three‐excavation and one‐masonry” construction, the temporary support span of the main shaft was adjusted to 12 m, which can make the subsequent concrete shaft wall in the state of “no pressure bearing or slow low pressure bearing,” and the lining compressive safety coefficient was increased to 1.98, which meets the safety requirements.

Improvement of power quality stability control method in solar power generation

Improvement of power quality stability control method in solar power generation

Stability Control for a Centripetal Force Type-Magnetic Bearing-Rotor System Based on Golden Frequency Section Point

Synchronous vibration and gyroscopic effect are the key factors affecting the global stability of flywheel batteries in the full speed region. The existing control methods generally treat them as two separate problems; however, they have something in common that can be exploited. In this article, a novel stability control method based on golden frequency section point is proposed for gyroscopic effect and synchronous vibration. The golden frequency section point is the bifurcation point of the nutation and precession of gyroscopic effect, and it is also the switching point of the control method with synchronous vibration at low and high speed. A case study of the centripetal force magnetic bearing-rotor (CFT-MB-R) system is taken as an example to verify it. First, the dynamic model of magnetic bearing rotor system is established. Then, the golden frequency section point is designed, and on this basis, the stability in the low-speed region and the high speed region are analyzed, respectively. Finally, simulations show that the vibration amplitude is reduced by nearly 50% at low speed and 66.6% at high speed. Moreover, the vehicle condition simulation results show the robustness of the system can also be improved. The experimental results further indicate that the method is an effective in suppressing the synchronous vibration and gyroscopic effect of the rotor system, and the stability and even robustness of the system can be greatly improved.

Managing driving disturbances in lateral vehicle dynamics via adaptive integrated chassis control

This paper presents a vehicle stability control method based on a multi-input multi-output (MIMO) model reference adaptive control (MRAC) strategy as an advanced driver assistance system (ADAS) to enhance the handling and yaw stability of the vehicle lateral dynamics. The corrective yaw moment and additive steering angle are generated using direct yaw moment control (DYC) and active front steering (AFS) at the upper control level in the hierarchical control algorithm. A nonlinear term is added to the conventional adaptive control laws to handle parametric uncertainties and disturbances. The desired yaw moment generated by the upper-level controller is converted to the brake forces and is distributed to the rear wheels by an optimal procedure at the lower-level. The major contribution of this study is the introduction of a nonlinear integrated adaptive control method based on a constraint optimization algorithm. To verify the effectiveness of the proposed control strategy, the nonlinear integrated adaptive controller, and linear time-varying MRAC are designed and used for comparison. Simulation results are performed for the J-turn and double lane change (DLC) manoeuvres at high speeds and low tyre-road friction coefficients. The desired performance of the proposed controller exhibited significant improvement compared to the conventional MRAC in terms of yaw rate tracking and handling of sideslip limitation.

Direct yaw moment control of an ultra-lightweight solar-electric passenger vehicle with variation in loading conditions

Large variations load-to-curb weight ratios are linked to significant changes in parameters critical to control design for vehicle stability control system. Unique and highly customised vehicles, such as the lightweight solar car in this paper, are more susceptible to the impact of such variations when developing control methods. The purpose of this study is to study the influence of variation in loading conditions, the effect of ignoring changes in inertial parameters, and develop and compare a number of alternative vehicle stability control methods that can be applied to rear-wheel driven vehicles via in-wheel motors. In this paper a Sliding Mode Control (SMC) both nominal and when including uncertainty, Dynamic Curvature Control (DCC) and a Proportional–Integral Control (PI) strategies are compared to the baseline open-loop control case. Each controller is implemented through co-simulation via MATLAB® Simulink® and Siemens Amesim™ using a 15-DOF non-linear vehicle model. The results show that SMC achieves the best performance, whilst DCC tends to overshoot target conditions prior to settling, indicating that SMC is the preferred control strategy. It is also demonstrated that by ignoring the change in the inertial parameters in simulation environments can produce an incorrect translation of the control performance.

Finite‐time active shimmy control based on uncertain disturbance observer for electric vehicle with independent suspension

For attenuating the shimmy phenomenon appeared in an electric vehicle (EV) with independent suspension, this study proposes a finite-time active shimmy stability control method based on an uncertainty estimation observer. Firstly, a four-degree-of-freedoms shimmy model of an EV with independent suspension is constructed. Secondly, in order to deal with the uncertainties in the shimmy model, a finite-time control method via a non-linear uncertain disturbance observer is proposed. The direct Lyapunov function method is used to analyse the global stability of the closed-loop system, and the results show that the system outputs globally converge to zero. Simulation and hardware-in-the-loop simulation test results verify the built shimmy model and show the effectiveness of the designed control method compared with the sliding mode control method.

Vehicle Lateral Stability Control Based on Shiftable Stability Regions and Dynamic Margins

Vehicle lateral stability control is one of the most critical aspects of vehicle safety control. In this paper, aiming at keeping the vehicle states (lateral velocity and yaw rate) always in the vehicle stability regions, a novel lateral stability control method, which consists of shiftable region-based stability analyses and a corresponding stability controller, is proposed. In the stability analyses, two features of the stability regions are introduced. First, a shifting vector is formulated to explicitly describe the shifting feature of lateral stability regions, so that the shiftable regions are not necessarily re-estimated with respect to a varying steering angle input. Second, dynamic margins of the stability regions are formulated and applied to avoid the penetration of vehicle state trajectory with respect to the stability region boundaries. With these two features, the shiftable stability regions are feasible for an accurate stability analysis, where a projection method is adopted to determine the relative location/distance between the vehicle state point and the closest boundary of the stability region. Based on the analyses, a dynamic sliding mode controller, where the sliding surfaces are selected as the stability region boundaries with the proposed dynamic margins, is designed to keep the vehicle states always in the shiftable stability region. To validate the effectiveness of the proposed control design and analyses, two maneuvers through the co-simulation between Matlab/Simulink and CarSim, namely a high-speed constant cornering and a double lane change maneuvers, are presented and discussed.

An experimental study of the vertical stabilization control of a trimaran using an actively controlled T-foil and flap

This study experimentally investigated a control method for the vertical stabilization of a trimaran. Experiments were conducted on a bare trimaran, a trimaran with fixed appendages, and one with actively controlled appendages. A T-foil and flap were selected as the stability appendages and installed on the vessel, whose dimension and installation position are provided. Next, the T-foil and flap were uncoupled, and the stabilization controller for motion reduction of the trimaran was designed on the basis of the idea of the resultant force and moment with Kalman filter (RFMD-K). Finally, the experimental results demonstrate the effectiveness of the appendages and the proposed controller.

DYNAMIC MODELING AND STABILITY CONTROL OF FOLDING WING AIRCRAFT

During the deformation process, the dynamic modeling of the folding-wing aircraft presents the characteristics of multi-rigid、multi-degree of freedom and strong nonlinearity. At the same time, parameters such as aerodynamics/torque, pressure center, centroid and moment of inertia will also change greatly, which will seriously affect Flight stability. Therefore, this paper will mainly study the multi-rigid dynamics modeling and deformation stability control of the folding wing aircraft. The multi-rigid dynamic model of the folding wing aircraft is established based on the Kane method with the additional force and moment expressions. The functional relationship between the aerodynamic parameters and the folding angle is fitted through aerodynamic calculations. and the longitudinal dynamic characteristics of the aircraft at different folding angular speeds are analyzed. It is shown that the speed, height and pitch angle of the folding wing aircraft will change during the deformation process by analyzing the longitudinal dynamic characteristics, and the aircraft cannot maintain stable flight. A stability control method is proposed for the deformation process of the folding-wing aircraft based on the active disturbance rejection control theory. The nonlinear terms, coupling terms and parameter time-varying terms are regarded as the total internal and external disturbances in the longitudinal nonlinear dynamic model of the folding-wing aircraft, using the extended state observer to estimate and compensate the total disturbance in real time. The PD controller is proposed for compensated systems to realize decoupling control of speed channel and height channel. The stability of the system is proved by Lyapunov stability theory, and mathematical simulation is used to verified the stability of the folding wing aircraft. The simulation results show that the stability controller based on the active disturbance rejection control theory can solve the problems of strong nonlinearity and time-varying parameters caused by aircraft deformation, and ensure the high-precision and stable control of the aircraft.

Layered control of forklift lateral stability based on Takagi–Sugenofuzzy neural network

An anti-roll hydraulic cylinder is designed as an executive mechanism of the lateral stability control to provide lateral support force on the basis of an analysis of the structure of the forklift and the mechanism of lateral instability. A lateral stability layered control method based on Takagi–Sugeno (T–S) fuzzy neural network is proposed, divides the forklift lateral stability control into the upper identification layer, the middle control layer and the lower executive layer. Simulation and real vehicle test results indicate that the forklift lateral stability control method based on the T–S fuzzy neural network can effectively identify the forklift driving state, reduce the forklift rollover possibility and improve forklift safety under limited working conditions.

Study on deformation and stress evolution law of surrounding rock under repeated mining in close coal seam

ABSTRACT Aimed at the problem that the mining roadway is seriously affected by the repeated mining under the up-down successive cooperative mining mode, this paper takes Qiuci Coal Mine as the research background. Based on analysis of mining influence stage of A502 haulage roadway, the stress evolution and deformation law of surrounding rock of roadway are analyzed through similar simulation, the principle that the ratio of main stress affects the stability of roadway under the influence of repeated mining is obtained based on the plastic failure theory of surrounding rock of roadway, the roadway stability control method by periods and stages is put forward based on the principle of roadway stability control, and the numerical simulation scheme is designed to determine the reasonable coal pillar width and support mode of roadway. The results show that the coal pillar with the width of 8 m can reduce roof stress of roadway by 38.4% and 64.3% during the tunneling period and period after formation of roadway, and the principal stress ratio is reduced to 2; the stability of surrounding rock during and after excavation can be guaranteed by adopting φ20 × 2400 bolt and advanced hydraulic support. Through field measurement, the maximum deformation of A502 haulage roadway is only 60 mm, and the cumulative output of coal during the period of mining influence is 1,833,700 tons, thus the safe mining of coal mine is realized, and enormous economic benefits are generated.

Dynamic Decoupling and Trajectory Tracking for Automated Vehicles Based on the Inverse System

A simultaneous trajectory tracking and stability control method is present for the four-wheel independent drive (4WID) automated vehicles to handle dynamic coupling maneuvers. To conquer the disadvantage that attendant disturbances caused by the dynamic coupling of traditional decentralized control methods degenerate the trajectory tracking accuracy, the proposed method takes advantage of the idea of decoupling to optimize the tracking performance. After establishing the dynamic model of the 4WID automated vehicles, the coupling mechanism of the vehicle dynamic control and its negative effect on trajectory tracking were studied at first. The inverse system model was then determined by machine learning and connected in series with the controlled object to form a pseudo linear system to realize dynamic decoupling. Finally, differing from previous tracking methods following the apparent lateral position and longitudinal velocity references, the pseudo linear system tracks the ideal intermediate targets transferred from the target trajectory, that is, the accelerations of vehicle in longitudinal, lateral and yaw directions, to indirectly achieve trajectory tracking and validly restrain the vehicle motion. The effectiveness of the proposed method, i.e., the high tracking accuracy and the stable driving performance, is verified through three coupling driving scenarios in the CarSim-Simulink co-simulations platform.

Stabilization with guaranteed safety using Barrier Function and Control Lyapunov Function

The stabilization problem with guaranteed safety is motivated in the case that the systems might be at risk whenever certain unsafe states are reached. Consequently the design of controller must comply with state constraints and avoid unsafe states. This paper proposes a control method for stabilization with guaranteed safety for affine systems. Firstly, a novel Barrier Function (BF) is presented for bounded convex unsafe state set. The design of BF is only based on the unsafe state set and independent of Control Lyapunov Function (CLF). So besides its simpleness and ease of implementation, the presented BF needs weak constraint conditions and admits a larger class of functions. Based on the BF and a CLF, a necessary and sufficient condition is presented for stabilization with guaranteed safety for affine systems. Further, the proposed method can accommodate the case of multiple different sets of unsafe states immediately by only adding the corresponding BFs to the CLF and need not modify the design for the existing unsafe state sets. Finally, the obtained results are extended to the case that the unsafe set is a class of unbounded nonconvex set. Illustrative examples are given to show the proposed results.

Research on Model Predictive Control Method for Vehicle Lateral Stability Based on Hardware-in-the-Loop Test

With the rapid development of the vehicle chassis control and autonomous driving technology, it is more and more urgent to realize the active steering technology of autonomous driving stability control. Under emergency conditions, the adhesion constraints, the model uncertainty, and the strong nonlinearity of vehicle bring great challenges to active steering control. In this paper, a model predictive control method for an active steering system based on a nonlinear vehicle model is proposed to solve the problems of adhesion constraint, model uncertainty, and external disturbance in the active steering system. Based on the real-time measurement of vehicle state, a new optimization method is proposed in this paper, which has good performance in dealing with the uncertainty and nonlinearity of the model. The control method transforms the constraint problem into quadratic programming and nonlinear programming. In order to ensure the control accuracy when the vehicle enters the nonlinear area, the control model is built with the combination of the nonlinear tire model and the 2DOF model. The control model is built based on Simulink, and the effectiveness of the controller is the verified joint simulation of Simulink and CarSim. The hardware-in-the-loop (HIL) test bench based on LabVIEW RT is built and tested in order to verify the feasibility and real effect of the controller. Simulation and HIL test results demonstrate that, compared with PID controller, the model predictive controller can accomplish the driving task well and improve the vehicle handling stability.

Review of electrolytic capacitor-less PMSM drives

<p indent=0mm>Electrolytic capacitor-less permanent magnet synchronous motor (PMSM) drives could improve the reliability and reduce the cost and volume of a drive system, which would be an important improvement over a conventional motor drive system. This has been successfully applied in aerospace, industry, and household applications. In this study, the development of the electrolytic capacitor-less PMSM motor drives is introduced, including the high power factor control, the grid harmonics suppression, and the stability control method. The key technique and related studies are summarized, and the advantages and disadvantages of this solution are illustrated and evaluated. Finally, the key issues and the development trend toward electrolytic capacitor-less PMSM drives were analyzed and summarized.

A Data-Based Learning and Control Method for Long-Term Voltage Stability

Based on the knowledge accumulated off-line and feature extractions, a novel data-based learning and control method is proposed for the long-term voltage stability problem in this paper. All the spatial-temporal data is considered and the features of different emergency events are extracted by principle component analysis which can reduce the dimension and reveal the significant internal structure of the data. An artificial neural network is used to build a classifier to reinforce the relationship directly between the system dynamics and optimal control actions. With the prepared control knowledge, it is faster to find an optimal control action online with a good system performance. Simulation results on the 6-bus system, New England 39-bus system and Iceland 189-bus system are given to show the potential of this method for on-line control.

Online Preventive Control Method for Static Voltage Stability of Large Power Grids

The real-time preventive control is particularly critical because the integration of renewable energy aggravates the random fluctuation of large power grid operating state. An online preventive control optimization method for static voltage stability is proposed based on the Thevenin equivalent parameter identification. According to the definition of the stability margin, its quantitative relationship with the control variable is derived to meet the real-time and reliability requirements of online applications. The preventive control optimization model is constructed to minimize control cost and consider voltage stability margin and operation constraints under multiple critical contingencies. The generator terminal voltage and shunt capacitor in this paper are taken as continuous and discrete control variables respectively. The derived analytical relationship between stability margin and control variable is linearized to form linear security constraints, and the optimization model is transformed into a mixed-integer linear programming problem, which can be solved by CPLEX quickly and reliably. The accuracy and rapidity of the proposed method are verified on several test systems.

A new sensitivity approach for preventive control selection in real-time voltage stability assessment

Voltage instability is one of the serious problems in power networks due to the growing demand. Sensitivity analysis has been widely hailed as an effective method for voltage stability prediction and control. However, the common loading margin sensitivity approaches are not appropriate for real-time applications. This is because those approaches are based on continuation power flow or the singularity of the Jacobian matrix to find the maximum loading point. In this study, a new sensitivity method is developed for choosing the most effective control variables for voltage instability prevention in power systems. The sensitivity analysis is performed on a voltage stability index, namely Thevenin-Based Voltage Stability Margin (TVSM), derived from the coupled single-port circuit concept to capture the changes in power system operation. The sensitivity approach is computed via the derivation of nodal voltages (magnitudes and angles) with respect to preventive controls. The proposed sensitivity approach is tested on the IEEE 39 bus network and the IEEE 118 bus network to verify their accuracy.

Internal Model Control Tuned Proportional Integral Derivative for Quadrotor Unmanned Aerial Vehicle Dynamic Model

In recent times, there are has been growing substantive attention to the quadrotor Unmanned Aerial Vehicle (UAV) stability control. However, inherent nonlinearity is a major challenge with this control technique, this paper, therefore, developed a PID based Internal Model Control (IMC) method for the dynamic model of quadrotor UAV. The versatility and simplicity of the Proportional-Integral-Derivative (PID) controller enable it to enjoy wide usage and acceptability as stability control methods for the unmanned aerial vehicles. The aim of this paper is to use the PID controller with IMC to control a UAV. The proposed approach - IMC-PID control method -was simulated using MATLAB software and X-plane flight simulator. Thereafter, a comparative analysis of the IMC-PID control method with Chien-Hrones-Reswick, Cohen-coon, and Ziegler Nichols based PID Controllers was done using pitch and altitude as performance metrics. Keywords: Internal Model Control,MATLAB/Simulink , Proportional Integral Derivative, Quadrotor, Unmanned Aerial Vehicle (UAV),X-Plane, DOI: 10.7176/CTI/9-01 Publication date: April 30 th 2020

Posture stability control of a small inverted pendulum robot in trajectory tracking using a control moment gyro

ABSTRACTThis paper reports on a posture stability control method for an inverted pendulum robot using a control moment gyro (CMG) mounted on the top of the inverted pendulum. As an inverted pendulum dimension decreases, a time to fall over to an angle where an inverted pendulum cannot restore its posture becomes shorter; however, a small inverted pendulum robot cannot have a powerful computer because of space limitations. This means it requires a faster and smaller way to maintain its balance. Furthermore, inverted pendulum robots require movement space to gain a restoring force to keep their balance. We thus proposed an inverted pendulum robot using a CMG to obtain the necessary restoring force. The CMG’s effects decreased the robot’s falling over speed, meaning it can keep its balance without moving. We successfully demonstrated that an inverted pendulum robot with a CMG can separate posture stability control and trajectory tracking control. The validity of the inverted pendulum robot with a CMG was confirmed comparing the two experiments. In the first experiment, the CMG performed posture stabilization and the wheel performed trajectory tracking. In the second experiment, only the wheel performed posture stabilization and trajectory tracking.