The process of projectile band bayonet-chamber of a new type 155mm howitzer is analyzed to investigate the effect of band bayonet-process parameters on the initial conditions of motion of projectile in bore, and the effects of changes in various parameters of band bayonet-process are presented, such as projectile velocity, frictional coefficient, quadrant angle, initial deflection and barrel-projectile gap. The results are obtained based on the dynamic explicit finite element method. Thus, the factors that influence the bayonet-chamber depth, band-barrel reaction force and bayonet-chamber posture are shown. Among them, the projectile velocity and frictional coefficient have significant influence on the bayonet-chamber depth and the band-barrel reaction force, the quadrant angle and initial deflection have major impact on the bayonet-chamber posture, meanwhile, the barrel-projectile gap playes an important role in all the three results. The results provide a parameter basis to the ammunition rammer design and the motion law of projectile in bore.

To explain the paradox between the experimental and theoretical results of equivalent full charge (EFC) conversion coefficient, which can be used to convert the number of firing under various firing conditions to the number of EFC firing, a computational method of that coefficient is investigated on the basis of the thermo-chemical erosion model of the barrel. Supposing that the thickness and composition of the white layer on the inner wall of barrel change periodically after several firings, the relationship among the thermo-chemical erosion volume at the beginning of the rifling and the erosivity of the propellant and the transient temperature field of the inner layer of the barrel is established with the help of the mass diffusion law. During the firing process, the gas temperature in the space behind the projectile and the forced convection coefficient at the innerwall surface of barrel are provided by the classical interior ballistic theory. Hereafter, the model to calculate the transient temperature of the barrel can be developed. In addition, the effect of gas with relative high temperature during the after-effect period is also considered. Eventually, focusing on the firing rate, the charge mass and the charge temperature which have an essential effect on the interior ballistic process, erosion volumes under different firing rates, charge numbers and charge temperatures are calculated. Accordingly, the EFC conversion coefficients under various firing conditions are obtained. It is found that a more severe erosion of the barrel is often related to a faster firing rate, a more charge mass and a higher charge temperature.The EFC coefficient of the supercharge is up to 2.131. The reasonability of the proposed model is verified by using the practical firing data of a 155mm barrel.

The fluctuation of projectile motion parameters before bayonet-chamber is reduced, i.e., improving the consistency of ammunition ramming, to improve the consistency of bayonet-chamber. The random parameters in the ramming system are summarized according to the operating principle of ramming mechanism and the experimental results. Based on MSC.ADAMS, a dynamic model for ramming process of a ramming mechanism, in which the parameter randomness are taken into account, is constructed. A robust optimal design model of ramming mechanism for consistency of ammunition ramming under the constraint of minimum 3 m/s bayonet-chamber velocity is established for minimizing the standard deviation of the motion parameters before bayonet-chamber. The optimization calculation efficiency is improved by using the global and local combinatorial optimization algorithms, and the descriptive sampling. Numerical examples show that the bayonet-chamber velocity meets the requirements, and the consistency of ammunition ramming is improved after optimization, which verifies the effectiveness of the method. Key

The effects of the state parameters of projectiles at muzzle on the dispersion of projectiles are analyzed. Based on the six-degree-of-freedom ballistic equations, the sparse grid numerical integration (SGNI) method is used to obtain the characteristic paramerers of projectiles dispersion considering the error factors of system parameters and the state parameters of projectile at muzzle. The probability distribution of projectiles dispersion is obtained by using the the maximum entropy method. The test examples show that the results obtained by the SGNI method are in good agreement with those obtained by Monte Carlo method, and verify its effectiveness. In addition, an engineering example of 155 mm gun-howitzer is ananlyzed, and the the relation between single state parameter error and multi-state parameter error and the projectiles dispersionis established, which can be provided as reference for the overall design cosidering the dispersion of projectiles. Key

In order to improve the design quality and efficiency of self-propelled artillery in consideration of a large number of variant design problems existing in self-propelled artillery design, the case-based reasoning technology is introduced into the solution procedure for self-propelled artillery variant design problem. The process of hybrid case reasoning is determined according to the characteristics of self-propelled artillery design case and the requirements of variant design. The ontology-based case representation technique is studied, and a self-propelled artillery design case ontology is built.The similarity calculation formulas for different scenarios are determined for the self-propelled artillery case retrieval. On this basis, the solution of design parameters for variant design problem is achieved by using neural network-based parameter prediction technique. The feasibility and effectiveness of the proposed method are demonstrated by taking recuperator design for example.

To study the mechanical mechanism and motion law of the high speed impact engraving process of cased telescoped ammunition, the physical and mathematical interior ballistic models were analyzed and established with a 40mm caliber CTA gun as the research object, and the interior ballistic model was verified by live fire experiments. Considering the friction and contact characteristics between the interfaces, a high-speed impact engraving model was built by the FEM-SPH coupling algorithm, and the numerical solution of the interior ballistics was used as the boundary condition to obtain the change laws of the deformation of the rotating band, projectile motion, projectile attitude and engraving resistance by numerical calculations. The results showed that: the established ballistic model is accurate and reasonable; the initial velocity of the projectile at the bore was 78.2m/s; the entire engraving process can be divided into the decelerating and accelerating phases, and the projectile was in the quasi-static state between the two phases; during the decelerating engraving process, the projectile attitude changed periodically, and the amplitude of the oscillation angle decreased continuously; the oscillation angle increased rapidly during the accelerating engraving process; as the engraving was completed, the oscillation angle showed a decreasing trend; the engraving time was 2.65 ms and the projectile velocity was 73.92 m/s at the completion of engraving; the surface temperature of the rotating band during the engraving process was close to the melting point of the material; there were two "rise - fall" processes in the dynamic engraving resistance with the maximum engraving resistance of 95.288 kN, and the resistance decreased and stabilized at 10 kN at the moment of fully engraving.

An adaptive fuzzy sliding mode controller (AFSMC) with an integral sliding mode function is proposed for the control of the artillery modular charge transport servo system which has time-varying parameters and chattering problem. The time-varying system parameters are estimated by using adaptive method. The influence of model uncertainty on the control system is reduced. Then, the traditional switching function is replaced by an improved saturation function. This ensures that the process of switching is more continuous and smooth. The coefficient of switching is tuned online by the fuzzy adaptive scheme. In this way, the robustness of system is enhanced, and the chattering of system is restrained. Experimental results show the system has a good position tracking performance under empty-load, half-load and full-load, which can meet the performance index. The proposed AFSMC scheme can overcome the influence of variable loads on the control precision of the system. Key

The projectile is disturbed by high-pressure gas during aftereffect period, which affects its exterior ballistic characteristics. The change of pressure on the base of projectile during the aftereffect period is studied for improving the accuracy firing table and optimized design of projectile. As computational fluid dynamics (CFD) simulation takes a long time, a theoretical model based on Prandtl-Meyer wave and isentropic flow is established for predicting the pressure on the base of projectile, and a modified model of pressure boundary estimation is proposed. The muzzle dates measured in a firing practice test were analyzed. The results show that the simulated results of the proposed model and CFD 3D model have less difference, but the calculating time of the proposed model is shorter, which is decreased from about 1.5 h to less than 1 s. Key

In order to analyze the kinematic accuracy and dynamic characteristics of open chain drive transmission for a ramming mechanism, the geometrical relationship and contact modes of roller and sprocket as well as the contact between chain links are described in detail, and then the normal contact force model and the plane contact force model are established for different contact modes. An accurate dynamic model of open chain drive transmission mechanism is established. The characteristics of contact between roller and sprocket are analyzed, and the effect of the change in clearance between roller and sprocket on kinematic accuracy and the dynamic characteristics is discussed. The results show that the clearance between roller and sprocket has great influence on the dynamic characteristics of open chain drive transmission mechanism of the ramming mechanism. The clearance between roller and sprocket should be controlled in reason during the engineering. Key

A platform-sling model is established to study the dynamic response of airdrop platform. An uniform equivalent point Newton-Rapshon iteration method is presented. In order to study the unsteady fluid behavior, the time domain is discretized, and an ALE base finite volume method is used to solve the NS equations. The aero-force is obtained and imposed on the platform. The equivalent point method is validated through commercial software RECURDYN. The results show that the equivalent point method can well represent the slack-taut cases of the sling system. It can also be found that the laminar flow model is used to describe the acting force of fluid on plate well at low Reynolds number. Finally, the comparisons are made between the steady and unsteady FSI models. The time history of unsteady fluid force displays severe oscillation while the steady fluid force varies evenly.

In order to accurately simulate the dynamic response of the elevating equilibrator in the state of gun launch, an elevating equilibrator dynamic model in the state of gun launch is established based on the theoretical model of air-liquid mixtures of hydraulic oil， the cylinder stiffness and the structure of elevating equilibrator. ADAMS software is used to build a parameterized dynamic model of elevating equilibrator， and the parameters to be identified are established. The model parameters are identified using the particle swarm optimization algorithm based on the test data of a vehicle-mounted gun and the gun launching dynamics model. The simulated results agreed with the experimental data， thus verifying the accuracy of the proposed model and the availability of the parameter identification results. The sensitivities of the parameters of elevating equilibrator dynamic model to the pitching motion of gun were calculated．The results of sensitivity analysis show that several parameters， such as air content and initial pressure， have a large impact on the pitching motion of gun.

The modern automatic loading system for large caliber guns involves the collaborative control of multiple motors. The application of sensorless technology can significantly improve the reliability of driving systems. The rotor position identification of surface-mounted permanent-magnet synchronous motor at zero-/low-speeds is a difficult problem in sensorless control. To deal with it, an extended Kalman filter based on mechanical motion model is proposed to assist rotor position estimation. At the same time, the observer disturbance rejection technology is employed to eliminate the influence of disturbances such as model parameter uncertainty to rotor position identification, and to realize reliable start-stop control under zero/low speeds and heavy loads. The proposed method overcomes the limitation of the conventional rotor position estimation method based on the electrical model, greatly improves the load capacity of the sensorless technology at zero/low speeds, and realizes the performance comparable to that of the position sensor servo. This sensorless motor control technology is applied to the 155 mm gun loading system. Finally, the technology is verified by the operation simulation of the modular explosive loader and projectile loader as examples.

To investigate the mechanism of engraving process and the rule of initial motion of projectile during lauching process, the engraving process of rotating band of large-caliber howitzer is simulated. The gas pressure distribution of propellant in the tapered chamber is taken into consideration to get the interior ballistic equation during engraving process, and the solution of the equation is taken as the boundary condition of coupled thermo-mechanical analysis of engraving process. Meanwhile, the friction between the rotating band and the barrel is modeled using modified Coulomb model in which the temperature at the interface is taken into consideration. Uncoupled internal ballistic engraving process and adiabatic engraving process are calculated to verify the necessity of the coupled analysis. The resistance, projectile velocity, propellant gas pressure and projectile attitude are got by considering the changes in clearance between projectile and barrel, initial velocity and initial projectile attitude. The calculated results show that the clearance between projectile and barrel plays an important role in determining the resistance and projectile velocity, and the initial projectile attitude has a great effect on the projectile attitude in the process of engraving.

The prototype of a high firing rate automatic mechanism of a gun has a periodic fire stop failure during firing. The classical thermal expansion theory and the finite element method are used for the thermal-structure coupling analysis of high firing rate automatic mechanism. The analysis results show that the size of its structure can be appropriately adjusted to meet the requirement of the current firing rate and further improve the rate of fire. The improved structural design of demonstration prototype has non periodic fire stop phenomenon after several rounds of live ammunition tests. Thermal-structure coupling method can be used to solve similar failures in engineering practice.

The resultant force in the bore during after-effect period of artillery becomes significant in analyzing the motion of artillery. As the spatial distribution of propellant gas flow properties in the conventional theoretical assumption of after-effect period does not strictly conform to the numerical solutions, a set of differential-integral equations describing the gas flow distribution are derived from the governing equations of in-bore gas. A numerical method is then proposed for solving the equations. Formulas for evaluating the gas flow properties, the resultant force in the bore, and the after-effect coefficient are obtained based on the gas flow distribution. The calculated results of the formulas in this paper and the conventional theories were compared with the numerically simulated results.The results suggest that the gas flow distribution and the resultant force in the bore calculated by the proposed formulas are in fantastic agreement with the numerically simulated ones. The error between the analytical and computational after-effect coefficients ranges from 0.38% to 1.80%.

For the problem of that the various design knowledges of self-propelled artillery have not been organized and represented effectively and the existing design knowledge cannot be reused simply during the design process, a knowledge representation method is proposed based on ontology and knowledge components. The organization mode for design ontology of self-propelled artillery and the developing strategy for knowledge components are studied on the base of analyzing the representation requirement of design knowledge of self-propelled artillery, and the mapping relationships among design ontology and knowledge components are established. The representation of design knowledge of self-propelled artillery is achieved. On this basis,a special knowledge retrieval system is developed for designers to quickly reuse the existing design knowledge. The representation and reuse of design knowledge are implemented by taking large-caliber self-propelled artillery for example. The result shows that the proposed method is feasible and valid.

To investigate the effect of rotating band on the aerodynamic characteristics of high-speed spinning projectile, the second-order Roe-type upwind scheme and SST k-ω turbulence model are used to solve the three-dimensional Navier-Stokes equations. Moving boundary caused by the spinning of projectile is processed using sliding mesh method. The aerodynamic characteristics of 155 mm spinning projectile without rotating band are calculated, and the numerical results are in good agreement with the wind tunnel test data presented in Ref.［6］. The flow fields over high-speed spinning projectiles with and without rotating band are simualted under the conditions of different Mach numbers and angles of attack. By analyzing the differences of flow-field structures and aerodynamic characteristics, the conclusions are drawn as follows: the pressure distributions of two projectile models in front of rotating band are basically identical, but the rotating band structure increases the aerodynamic resistance area of the projectile, thus leading to the increase in resistance coefficient, and there is a great difference between the pressure distributions of the two spinning projectiles in the rear of the rotating band. This proves that the impact of the rotating band structure on the aerodynamic characteristics of spinning projectile cannot be neglected. Key

An optimization method for shell elevating device with interval uncertainties is proposed to solve the problem of performance degradation during operating. A multidisciplinary model based on ADAMS is established. The parameters of hydraulic system and the friction coefficient are regarded as the interval uncertainties, and the minimal loading and fluctuation on the mechanism are set as the objectives by using the interval theory. Simulations are carried out on Latin hypercube sampling (LHS) points. An approximate model of shell elevating device is constructed based on radial basis function (RBF) neural networks to improve the efficiency. The nested optimization method based on multi-island GA and NLPQL is used to obtain the robust solutions. The simulation and experimental results demonstrate the efficiency and adaptability of the proposed method for solving the complex problems in automatic loading system.

Considering the influence of muzzle brake and breech ring, an elastic dynamics equation of the barrel is established. Combining the advantages of the finite element method and the meshless method, an element supported domain radial point interpolation method is proposed based on the radial basis point interpolation method, in which the element supported domain is treated as the interpolation domain of the integration point to establish the discrete elastic dynamics equation. The natural frequencies of barrel are estimated by solving the dynamic equation. Finally, the effectiveness of the proposed method is demonstrated by numerical examples and experiments, and the results show that the proposed method can provide more accurate results with the same element number，which can coincide with the experimental results. Key

For large inertia, load nonlinearity, parameter uncertainty and disturbance in the electro-hydraulic position servo system of vehicle-mounted howitzer, a fault detection scheme based on nonlinear unknown input observer is proposed. After modeling the system, a nonlinear observer design is utilized to generate the residual signals required for fault detection. The observer's stability is proved and its existing conditions is given by Lyapunov stability theory. The observational ability and fault detection ability of observer are detected online on a fault detection test rig. A dynamic threshold failure decision mechanism based on statistics is designed, which eliminate the false alarm of fixed threshold in transition stage. The experimental examples are investigated to demonstrate the effectiveness of the proposed fault detection scheme, which can be applied for the online fault detection of the electro-hydraulic position servo system. Key

A uncertainty analysis method for ammunition ramming process based on probability density evolution theory is proposed to analyze the influence of uncertain parameters in ammunition ramming process on the consistency of ammunition ramming. The ADAMS dynamic model of ramming process is established. The generalized probability density evolution equation of ramming process solved by finite difference method based on Lax-Wendroff scheme is derived，in which the relationship between state space and probability space is established by the joint probability density function of projectile state variable and random parameters of ammunition ramming process.The simulated displacement curve of ADAMS model is basically consistent with the experimental data，which verifies the accuracy of the proposed model. Compared with the Monte Carlo method，the response probability density function calculated by the proposed method is acceptable.The influence of parameter uncertainty on the projectile response under different working conditions is analyzed，and the mean square error of response is calculated.The results show that the fluctuation range of projectile response expands with the increase in ammunition ramming angle.

A disturbance observer-based adaptive sliding mode control strategy is proposed for ammunition manipulator electro-hydraulic servo system with unmatched and parameter uncertainties. A disturbance observer is adopted to estimate the unmatched uncertainties in the system, and the stability of disturbance observer is proved by Lyapunov stability theory. In order to effectively compensate the unmatched uncertainties and improve the control accuracy, the disturbance observer is introduced into the design of integral sliding mode switching function. An adaptive law is introduced into the design of sliding mode controller to improve the dynamic performance, which reduces the influence of system parameter uncertainties. Besides, the global stability of the controller is proved. Experimental results show that the disturbance observer and the adaptive law can accurately describe the system characteristics, the disturbance observer-based adaptive sliding mode controller proposed in this research tracks the desired tracking trajectory well. The designed controller has strong robustness and guarantees prescribed dynamic tracking characteristics and final steady-state accuracy under different operating conditions.

For a propellant transport mechanism with small-angle propellant transport and non-full charge transport, a robust optimal design method for propellant transport mechanism based on polynomial sparse chaos expansion (SPCE) is proposed. A dynamic model of a propellant transport mechanism is established, and the correctness and validity of the model are verified through experiment. A surrogate model of uncertainty input parameters for position of propellant transport is obtained using SPCE. Finally, a robust optimal design model of a propellant transport process is constructed with the target of minimizing the in-place and standard deviations. The optimization model is calculated with NSGA-Ⅱ algorithm. The results show that the in-place consistency is improved after optimization, and the standard deviation is reduced by 26.74% relative to initial deviation, thus proving the effectiveness of the method.

An adaptive robust control scheme with integral sliding surface is proposed for the precision position control of the rotational chain shell magazine. The integral operation sliding surface is embedded into the traditional adaptive robust control, and the steady state position tracking error is reduced. Constant robust feedback gain is replaced by nonlinear robust feedback gain, and the transient performance is improved. Mathematical analysis shows that the proposed control scheme can achieve better transient performance and has smaller steady state position tracking error. Simulation results in three conditions (empty-loading, half-loading and full-loading) show that the proposed control scheme is insensitive to parameter variations and external disturbance. Compared with the traditional adaptive robust control scheme, the proposed control scheme has higher position precision and better control performance.

Launch load transfer control is key to the lightweight and high maneuverability design of truck-mounted howitzers, and has always been a hot issue in the field of artillery research. To control launch load transfer, according to the configuration characteristics of truck-mounted howitzers, the presented work puts forward the basic principle of launch load separation design for chassis subjected to launch load, and constructs the constraint conditions for launch load separation. Based on the topological structure of a truck-mounted howitzer, its dynamic launch model is established, and the boundary conditions, the release coordination conditions as well as the constraint conditions are given. The correctness of the model is verified by comparing the calculation results and experimental data of the load and response of the key components in the launching process of the truck-mounted howitzer. In addition, through the analysis of the load on tires with different support structures and the firing stability, the results show that the load separation design for the truck-mounted howitzer can not only avoid the influence of the launch load on the chassis wheel bridge system, but also guarantee that the truck-mounted howitzer has the same reliability as the chassis. Moreover, the load separation design also plays a positive role in improving the performance of the truck-mounted howitzer, which verifies the effectiveness of the load separation principle and realizes the functional integration and performance decoupling design of the vehicle and the howitzer. The load separation design for truck-mounted howitzers realizes the requirements of a light chassis to bear the strong impact load from launch. It is an ideal method for highly mobile launch of long-range artillery.

This study aims to analyze the kinematic accuracy reliability of a swing mechanism with an automatic loading system and calculate the reliability sensitivity of dimension parameters. A kinematical model of the swing mechanism is thus established. Considering the influence of dimension error of the swing mechanism and joint clearance, the first four statistical moments are obtained by using the spare grid numerical integration method, and the probability density function of the kinematic response variable is obtained using the saddle point estimation method. The kinematic accuracy reliability of the swing mechanism with the automatic loading system is then calculated, and the reliability sensitivity analysis of dimension parameters is performed based on the results. The simulation results show that the calculation results in the study are identical to those acquired using the Monte Carlo method while requiring fewer sample points. The effectiveness of the methods in the paper is verified, and there is less failure probability of the swing mechanism kinematic accuracy, indicating high reliability in kinematic accuracy. The reliability sensitivity analysis of the dimension parameters reveals that the length of the driving arm has a larger influence on the kinematic reliability, while the other parameters have less influence. This provides references for the reliability-based design of the swing mechanism.

The shock wave overpressure acting on the surface of crew compartment during artillery firing is a key boundary condition for studying the protective performance of vehicle-mounted howitzer’s crew compartment against muzzle shock wave. To explore the characteristics of muzzle shock wave overpressure on the surface of crew compartment, a systematic firing experiment plan is designed for a specific equipment. The experiments cover both the main and auxiliary firing sectors of vehicle-mounted howitzer, capturing the overpressure data of the shockwaves at different positions on the crew compartment under seven firing angle conditions. The attenuation patterns of shock wave overpressure on the crew compartment surface at various spatial locations relative to the muzzle and crew compartment were obtained through experiment. A computational model of muzzle blast flow field is established using the unsteady three-dimensional inviscid Euler equations. Simulation and numerical analysis are performed to evaluate the shock wave overpressure on the crew compartment surface under extreme conditions.The simulated results show good agreement with the experimental data in terms of the change trend of shock wave overpressure, with a peak overpressure error of less than 4% when the muzzle airflow velocity is properly considered. The research results indicate that the muzzle shock wave influenced by the ground and the structure of crew compartment, forms a secondary overpressure distribution with obvious peaks on the surface of vehicle-mounted howitzer’s crew compartment. Factors such as the orientation of muzzle brake vents and the raised structures on the crew compartment contribute to a more severe muzzle shock wave overpressure on the surface of crew compartment.

The two-stage ignition and firing process of cased telescoped ammunition is experimentally researched to analyze the burning characteristics of charge and the movement characteristics of loadng and engraving. A high-speed camera system is used to capture the motion image sequences of every projectile group, and a test system for the procedural burning characteristics is devised and assembled. Based on the principle of digital image correlation, the image sequences are qualitatively and quantitatively analyzed, and the grooved morphology of the recovered band is analyzed and measured, so as to obtain the movement characteristics of projectile for one-stage ignition, the procedural burning characteristics for two-stage ignition, and the grooved morphology of the band. The findings demonstrate that the mass of fast-burning powder directly affects the loading performance of the first-stage ignition projectile. The loading time of projectile is significantly shortened and the loading speed is greatly increased when the mass of fast-burning ignition powder is increased. The premature fragmentation of combustible guide tube leads to a significant increase in the loading speed, resulting in a very poor band grooved morphology, which does not reliably seal the rear powder gas and steer the projectile motion, thus affecting the interior ballistic trajectory performance and the in-bore motion attitude of projectile. The reasonable matching design of fast-burning ignition powder and combustible guide tube can keep the break-up timing of combustible guide tube in a controllable range, so as to realize the ideal two-stage ignition and procedural burning design objectives.

To solve the problem of fault diagnosis of the modular charge feeding mechanism under multiple working conditions, a fault diagnosis method based on transfer learning and singular value decomposition (SVD) was proposed. SVD was used for dimensionality reduction and noise reduction as means of preprocessing of the modular charge velocity data and for feature extraction. The transfer learning method based on the TrAdaBoost algorithm framework was adopted to synthesize limited test data and a large amount of simulation data to extract effective fault information. In the information, multiple base fault classifiers were built and integrated into a high-quality fault classifier. The experimental results showed that the proposed method has good adaptability to the fault data under multiple working conditions, which can obtain better diagnosis accuracy compared to the traditional machine learning strategy in the case of limited test data.

Based on the existing researches on quasi-continuous algorithm, a novel improved quasi-continuous controller is designed to improve the precision and robustness of rotational shell magazine position control in the automatic loading process of a large caliber artillery.By combining a sliding mode disturbance observer, the novel controller is independent of the unknown system uncertainty boundary, and no new parameters are introduced, which will lower the difficulties of controller designing and adjusting.The stabilities of controller and close-loop scheme are verified by Lyapunov functions. The simulated and experimental results have demonstrated the superiority of the improved controller over the existing quasi-continuous algorithm.In the presence of unknown time-varying disturbance and uncertain parameters, the improved controller could achieve a higher convergence rate in reaching phase, reduce the overshoot and restrain chattering in sliding phase while performed on the magazine.