Journal of Military Science and Technology

Sliding mode in model-free control systems with adaptive parameters

Nguyen Van Duc, Nguyen Quang Hung, Vu Quoc Huy — Mon, 01 Apr 2024 00:00:00 +0000

The article synthesizes the model-free adaptive control law MFC-iPI-SMC for SISO nonlinear systems based on the development of the MFC-iPI control law operating in sliding mode to establish a new MFC-iPI-SMC control law to address the existing uncertainties of the system and establish mathematical constraints between parameters with the largest estimated disturbance error. The Lyapunov stability of the system is rigorously ensured mathematically. MATLAB simulation demonstrates the effectiveness of the new model-free adaptive control law.

The solution integrates the automatic stabilization system with the original fire control system on the anti-aircraft gun on the coast guard ship

Truong Tat Thuan, Le Viet Hong, Vu Hai Ha — Mon, 01 Apr 2024 00:00:00 +0000

This article presents a solution to improve the fire control system of the 23mm-2ML anti-aircraft gun currently equipped on coast guard ships based on the integration of an automatic stabilization system with a available tracking control system. By indirectly calculating the amount of velocity compensation in the direction and range transmission channels through the relay angle parameters of the ship deck and the angles of the gun transmission system, the article proposes a solution to keep the fire control system intact existing force combined with additional compensation right at the joystick output. The solution has been rigorously mathematically proven.

Improve the quality of tracking control for satellite antenna on Stewart plartform parallel drive system

Tran Trung Kien, Nguyen Trung Kien, Dang Nam Kien — Mon, 01 Apr 2024 00:00:00 +0000

This article builds a Terminal Sliding Mode Control (TSM) for each motor of six cylinder legs in a Stewart Platform parallel drive system of satellite tracking antenna. The proposed controller has limited the weaknesses of the controllers that have been researched, providing better quality and ensuring satellite tracking ability for the antenna in even cases with the largest angular amplitudes. The research results are simulated and demonstrated on MATLAB. The research results are simulated and demonstrated on MATLAB.

Investigating parameters in the dynamic configuration of four-wheeled and six-wheeled skid steering mobile robots to improve on-site rotation performance

Quach Xuan Nam, Dang Nam Kien, Le Duc Anh — Mon, 01 Apr 2024 00:00:00 +0000

This article studies the dynamic model of a four-wheeled and six-wheeled skid-steering mobile robot (SSMR), focusing on the on site rotation mode (zero turning radius). From there, the influence of some parametters in dynamic configuration of the robots on the rotation performance is built, without changing the robot's drive motor. Then the optimal choice of these parameters can be made to improve the robot's on-site rotation performance. The research results are simulated and demonstrated on MATLAB.

Improving measurement quality, reduce errors for two-chanel tracking transmission systems

Hoang Minh Sang, Phan Anh Tuan, Nguyen An Hai — Mon, 01 Apr 2024 00:00:00 +0000

Controlling specialized tracking systems requires high accuracy. These systems often operate in harsh conditions, so the control quality as well as each component in the system must meet design requirements. The two-plane tracking transmission system is one of the tracking control systems currently being researched, designed and improved at many research institutions. To improve control accuracy, use an angle measuring device with engraved magnetic lines. However, errors in the device itself, errors due to assembly and mechanical manufacturing lead to data received from the system being outside the required quality range. This article presents a method for handling measurement errors to improve the quality of data obtained from the system's terminal absolute position measuring device, ensuring that the system error is within the range of set technical requirements.

Research on the motion rules of the pan-tilt electromechanical system in the launch platform stabilization system on ships

Truong Tat Thuan, Le Viet Hong, Vu Quoc Huy — Mon, 01 Apr 2024 00:00:00 +0000

This paper has researched the motion rules of elevation and the azimuth of a pan-tilt electromechanical system used in the launch platform stabilized system attached to a ship. By using orthogonal coordinate systems, the line of sight vector associated with the elevation is located through Euler rotations. When the launch platform is stabilized, the angle and angular speed of the pan-tilt electromechanical are operated via a rule under the influence of the ship's sharking motion according to the wave level. The research results contribute to the scientific basis for calculating electric motor capacity and designing electric drive controllers for launch platform stabilization systems on ships.

Calculation and survey of angular motion parameters of ship-mounted antennas in satellite tracking

Le Van Phuc — Mon, 01 Apr 2024 00:00:00 +0000

To communicate with satellites, a system of antennas is required to transmit and receive signals to and from registered satellites. The transmission and reception of signals between the antenna and the satellite depends on many factors, such as transmit power, receiver sensitivity, and environment. To achieve the best signal level, the antenna must always be pointed toward the satellite it needs to communicate with. However, the attitude of a ship at sea is constantly affected by factors such as waves and wind, which can affect the antenna's line of sight. This paper presents a method for determining the antenna angles when affected by external factors such as waves and wind, and investigates its angular velocity to provide a basis for the design and manufacture of an antenna platform for satellite tracking. The paper simulates and evaluates the algorithm and presents the antenna platform's angle and angular velocity parameters under conditions where the vehicle's attitude changes within a defined range.

Reinforcement learning algorithm for adaptive intelligent control

Nguyen Van Duc, Sai Van Cuong — Mon, 01 Apr 2024 00:00:00 +0000

Nowadays, with the development of science and technology, control objects are increasingly complex, have high nonlinearities and large uncertainties, making traditional classic control algorithms no longer effective. That leads to the construction of unknown structures and parameters and requires advanced control techniques. To solve control problems with unknown elements in the dynamic models of the control object, the intelligent adaptive control method based on reinforcement learning algorithm is capable of automatically adjusting the parameters of the controller, proposed by the authors in this article. The effectiveness and feasibility of the proposed method are verified through practical simulation. The obtained comparative simulation results confirm that the proposed controller is robust, adaptive, and has high control performance.

Survey on error back propagation algorithm with the adaptive decay time for spike neural network in identifying the lift coefficient of an aircraft

Truong Van Khoa, Nguyen Van Tuan, Pham Trung Dung, Nguyen Van Hoa — Mon, 01 Apr 2024 00:00:00 +0000

This paper investigates the backpropagation algorithm with the adaptive decay time for the spike neural network. From the survey results, the author has determined the appropriate value range of decay time and learning rate to improve network training efficiency. The efficiency of the algorithm with the parameter values selected after the survey shows that the convergence speed of the network is improved compared to the original algorithm through the problem of identifying aircraft aerodynamic parameters.

A design strategy for analyzing signal integrity in DDR3 bus of high speed embedded systems

Nguyen Manh Hung, Phan Van Viet, Pham Minh Thang, Nguyen Van Khoi — Mon, 01 Apr 2024 00:00:00 +0000

A complex modern embedded system using a multi-core Central Processing Unit (CPU) toward a compact integrated design in a single Printed Circuit Board (PCB). One of the biggest challenges of the design is to meet the Signal Integrity for high speed Double Data Rate 3 Synchronous Dynamic Random-Access Memory (DDR3) bus. A typical strategy to solve the challenge is the simulation on the computer, but this is not always an effective solution as has a gap between simulation software and practical PCB. The gap is correlated to localized changes in copper density within the PCB and characterization of heterogeneous materials in PCB that could lead to differences in the real PCB. The purpose of the research presents an analysis methodology to design DDR) memory interfaces in high speed embedded systems, related to Signal Integrity and the impact of copper density on PCB trace impedances to overcome these challenges. Moreover, the presented design methodology is also applied to the next generation DDR as well as other styles of CPU.

Research on INS/Odometer combination model to detect spoofing points in navigation coordinates

Nguyen Trong Khuyen — Mon, 01 Apr 2024 00:00:00 +0000

This article presents a new method for detecting spoofing points in satellite navigation coordinates (GNSS) based on combining with the INS/Odometer model. In this article, the author presents a combined INS/Odometer model, using an 18-state Kalman filter; algorithm to detect spoofing points and method to combine GNSS with INS/Odometer to correct wrong coordinates. The INS/Odometer model allows accurate estimation of navigation parameters. Navigation coordinates from the INS/Odometer system are compared with coordinates obtained from the GPS satellite receiver to detect spoofing points in GNSS coordinates. The experiments demonstrate the correctness of the proposed algorithm.

Achieving zero secrecy outage in amplify-and-forward relaying systems

Huynh Huy Cuong, Nguyen Manh Hung, Nguyen Thi Ngoc Thuy, Ta Quang Hien — Mon, 01 Apr 2024 00:00:00 +0000

A proposed artificial noise (AN) injection strategy is considered in amplify-and-forward (AF) relaying systems. The limit of secrecy rate, hence the resulting zero-outage secrecy throughput, is determined subject to guarantee zero secrecy outage toward any powerful eavesdropper. The results show that the proposed simple strategy can achieve zero secrecy outage, which cannot be achieved in literature, and that it is easy to apply in wireless networks. The results also show an important finding: increasing throughput against increasing transmit power in secrecy.

Building a pre-calculated parameters table for 23 mm air defense artilleries based on the equations of air resistance

Vu Duc Tuan — Mon, 01 Apr 2024 00:00:00 +0000

This article researches, calculates, selects, and builds a pre-calculated anti-aircraft firing parameters table for 23 mm anti-aircraft guns based on the laws of warhead movement in the air environment under standard conditions by comparing research results with graphs and ground firing parameters tables available in the literature. Research results are calculated, simulated on MATLAB, and deployed on improved ZU23 systems.

Building a controller for a high-rise firefighting drone

Nguyen Duc Anh — Mon, 01 Apr 2024 00:00:00 +0000

On the basis of a dynamic model describing the movement of high-rise firefighting drones built by the authors using the Newton - Euler method as published, this article researches and builds a controller to stably control firefighting drones in normal motion and when the system launches the firefighting rocket for high-rise buildings in Vietnam. Due to the nature of the control object, the article chooses to use a rolling-integral controller combined with a feedforward compensation controller for the firefighting missile launch stage to perform the above task. Simulation results on Matlab/simulink show that the system is stable at the reference position and meets the requirements of the problem.

Synthesis of a sliding mode controller following the trajectory for automated guided vehicles AGV

Nguyen Dinh Long — Mon, 01 Apr 2024 00:00:00 +0000

Automated guided vehicles AGV are widely used in many fields such as factories, warehouses, post offices, etc. One of the key tasks of controlling AGV vehicles is to design a controller so that the vehicle follows the given trajectory well out under the effects of the system and surrounding environment. In this study, a method of synthesizing a sliding controller with an exponential approach law is proposed for 2-wheel differential active AGV vehicles. This method will move the trajectory of the AGV vehicle's parameters towards the sliding surface faster and reduce the chattering phenomenon compared to the method using the basic approach law, thereby helping the vehicle track the trajectory better during the operating process. Simulation results demonstrate the correctness of the proposed method.

The guidance algorithm for the UAV follows a complex path based on the Frenet coordinate system

Nguyen Hoang Viet, Nguyen Vu, Nguyen Thu Trang — Mon, 01 Apr 2024 00:00:00 +0000

This article presents the problem of controlling a fixed-wings UAV to follow complex paths when performing special tasks. To guide the UAV following complex paths, the article proposes a solution to apply the Frenet-Serret frame to the desired path and proposes a guidance algorithm. The stability of the guidance control law is proven by the Lyapulov function, the proposed algorithms are verified by simulation in Matlab.

Real-time target coordinate extrapolation in image processing

Nghiem Thanh Trung, Le Viet Hong, Vu Xuan Huy — Mon, 01 Apr 2024 00:00:00 +0000

The article addresses the issues of co-timing and problem solving in the image processing of automatic and focus calculation systems. By simultaneously searching the sample server control and the sample processing image acquisition time, the exact angle of the target is precisely determined during the sampling cycle during deodorization, so that the reserve angle is normally Its indication is determined in the current of the control cycle. To improve forecast quality, Kalman filter is used. The results of the paper have been rigorously proven and tested on a semi-natural simulation system.

Solution to create elevation and reception angles for anti-aircraft defenses when the observatory is placed on the gun's range channel

Le Danh Tuan, Pham Thi Phuong Anh — Mon, 01 Apr 2024 00:00:00 +0000

The article presents a solution for implementing the firing part for the fire control system when the observation post's pan-tilt platform is arranged directly on the artillery's range channel and the artillery platform is placed on a mobile vehicle. In this case, the angle of deviation between the line of sight and the line of fire is the elevation angle and pickup angle in the firing element in the ground fixed component coordinate system. The article has built a mathematical basis to calculate the rotation angle of the pan-tilt system to satisfy the given elevation and pickup angles. The results of the article are rigorously mathematically proven and shown on a number of examples and will be applied in fire control systems with pan-tilt systems placed on the gun's range channel.

A solution to build a simulation environment to synthesize data to determine the limited angle of attack parameters of the su-27 aircraft

Le Ngoc Lan, Phung Quang Khai, Ngo Doan Thanh — Mon, 01 Apr 2024 00:00:00 +0000

This article presents a solution to build a simulation environment to synthesize data to determine the allowable limit angle of attack parameters of the Su-27 aircraft. This parameter is determined to serve the process of researching and designing a limited signals computer of the Su-27 aircraft (under the information security conditions of the aircraft manufacturer, there are no aerodynamic parameters). The solution is simple and easy to apply to determine the limited angle of attack for Su-27 aircraft as well as other types of aircraft.

Research on building a solution to expand the working space for the crank - rod stewart platform

Nghiem Thanh Trung, Le Danh Tuan — Mon, 01 Apr 2024 00:00:00 +0000

The article addresses the issue of expanding the working space of the connecting rod-cranked Stewart unit. By constructing the inverse kinematics of the rod-cranked Stewart system precisely according to its parameters, the platform's responsiveness to the working space can be tested. To expand the working space for the pedestal, the article proposed to change some geometric dimensions of the pedestal. The results of the paper have been verified by simulation.

Target touch point determaining algorithm based on ultrasonic sensors

Vu Tran Phu, Pham Chi Thanh, Vu Xuan Huy — Mon, 01 Apr 2024 00:00:00 +0000

In this paper, the target touch point determaining algorithm based on ultrasonic sensors for evaluation shooting results is concerned. The target touch point determaining method is based on time difference of arival (TDOA) of ultrasonic shockwave to ultrasonic sensors. Derived equations are complicate nonlinear equations. In order to symplify in solving this equations, the sensor arrangement are considered for isolation of every unknown. The sensor arrangement diagram and target touch point determaining algorithm are proposed and strigly mathematically verified.

A method to improve image quality by mixing images from two different image sources

Le Khanh Thanh, Le Ba Tuan, Vu Quoc Huy — Mon, 01 Apr 2024 00:00:00 +0000

This article describes a method to improve the quality of infrared images by mixing images from two sources of conventional camera images and infrared images to observe the same scene. Two images from two different cameras do not have a consistent data structure: different resolutions, different fields of view (FOV), and different lens adjustments. To improve the quality of an image source, the images must first be converted to the same conditions. The two images are then mixed to enhance the quality of the infrared image. Experimental results show the effectiveness of the method when infrared image quality is improved.

Identification of time-varying parameters of linear time-varying systems

Le Van Tuan — Mon, 01 Apr 2024 00:00:00 +0000

Identification of time-varying parameters of linear time-varying systems is a complex problem, and until today there is still no general method to solve the above problem. In this article, a new identification method is proposed to help parameterize the control object model with parameters that vary linearly over time into a linear regression model. Then combine the use of dynamic regressor extension and mixing method (DREM) to estimate the parameters of this model to help increase the accuracy of convergence of the parameters to the real value. Simulations on Matlab/Simulink demonstrate the correctness of the proposed algorithm.

A hybrid automata and SysML-based model for controllers of autonomous surface vehicles

Cao Duc Sang, Le Tran Thang, Ngo Van Hien, Ngo Van He, Nguyen Trong Khuyen — Mon, 01 Apr 2024 00:00:00 +0000

Autonomous Underwater Vehicles/Autonomous Surface Vehicles (AUVs/ASVs) are increasingly being used in research, monitor and exploitation of marine resources. In particular, the design of control system for AUVs/ASVs is very important because it is closely connected to the hydrodynamic model of operating vehicles in the complex water environment. This paper presents a hybrid object-oriented control model, which is based on the specializations of hybrid automata and Systems Modeling Language (SysML), in order to systematically analyze, design and implement controllers of autonomous unmanned surface vehicles (ASVs). Based on this proposed hybrid model, a horizontal planar course-tracking controller of an ASV model was implemented and tested with good reliability.

Enhancing the accuracy of position and speed parameter determination for carrying devices through artificial neural networks

Hoang Van Long, Tran Duc Thuan, Nguyen Quang Vinh, Nguyen Duc Anh — Mon, 01 Apr 2024 00:00:00 +0000

This paper presents a method of applying an extended nonlinear Kalman filter to combine measured information from angular rate gyroscopes with magnetometers and accelerometers and satellite positioning information to estimate Rodrig - Hamilton parameters, position and speed of the carrier. In addition, the article also presents a method to improve the performance of the integrated global positioning system and inertial navigation system (GPS/INS) during GPS downtime, a new combined algorithm is proposed to provide virtual position and speed information to support an integrated positioning system, which is the application of ANN artificial neural network to improve accuracy when GPS is lost. The article focuses on improving the position accuracy and speed of carrier ships when GPS is lost. This issue is still new in Vietnam, and little has been published. The authors propose a solution to place a micromechanical gyroscope to measure angular speed, an accelerometer to measure apparent acceleration, and a magnetometer on the device to combine algorithms to solve the problem just mentioned above.

Institute of Military Technical Automation: Research and development of science and technology associated with practical applications

Tran Ngoc Binh — Mon, 01 Apr 2024 00:00:00 +0000

This article presents a summary of the science and technology research and development results in the automation field for security and national defense of the Institute of Military Technical Automation. The institute’s research products have been built on actual needs, with high scientific content and modern technology following development trends in the world. The practically-significant products have contributed to the task of modernizing weapons and equipment and improving combat capabilities and combat readiness of the Vietnam People’s Army. Through missions and tasks, the institute’s scientific force has gradually grown with a modern scientific and technological foundation, meeting task requirements in new situations. Promoting the achieved results, the Institute of Military Technical Automation has built the target orientations and key tasks in the next years to create highly applicable products that meet the modern warfare demand, contributing to building a strong army to firmly protect the Socialist Vietnamese Fatherland.