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The detailed model of the back-to-back converter of the permanent magnet direct drive wind power system contains multiple power electronic devices, and the use of pulse width modulation technology will inevitably increase the mathematical calculation of the simulation system. In view of the problem, a mean value model is proposed to simplify the system so that the wind power system can operate quickly and stably. For the converter mean value model, the controlled power supply is used to replace the converter in structure, and its higher harmonics are ignored in principle, and only the fundamental wave component is retained. In addition, from the perspective of system control, the control strategy of the system is improved by removing the PWM modulation process. Finally, a permanent magnet direct drive wind power system simulation model is built in MATLAB/Simulink, and the system response of the mean model and the detailed model are compared. The simulation results show that the mean value model can not only meet the system accuracy requirements, but also speed up the system simulation speed, greatly improve the system stability, which verifies the rationality of the control strategy. [ABSTRACT FROM AUTHOR]

Nowadays pollution and greenhouse gasses emissions led to the definition of action plans and guidelines aimed at improving renewable power production and circular & green economy approaches. Anaerobic digestion of organic wastes represents a meeting point between circular economy and bioenergy exploitation. The huge variety of residual biomass materials for anaerobic digestion makes clear the importance of the simulation process to underline biogas production and critical operating plant conditions for each kind of processed substrate and used reactors. Main target of this work is the definition of a software tool, called ADMS 1.0 (Anaerobic Digestion Model Simulator version 1.0), by which the user can conduct both implementation and simulation of anaerobic digestion biochemical processes (continuous-flow stirred tank reactors and batch reactors). This software tool is composed by an ad-hoc graphic user interface (GUI) developed in Python and a computing core, written in MATLAB. Anaerobic Digestion Model N.1 (ADM1) was implemented. Two simulations were carried out implementing the same scenario both in AQUASIM and ADMS 1.0 to validate the correct functioning and numerical consistency of the proposed tool. The scenario is based on experimental data. The results obtained by both software tools were compared to confirm the consistency of numerical outputs. Differences between these results have been measured by the introduction of a mean of the relative errors associated to the singular simulated biochemical component. This error, expressed in percentage, represents the discrepancy between AQUASIM and ADMS 1.0 results. The relative errors average value is equal to 0.0648%, which is consistently less than the acceptable engineering value of 5%.

In this study, a fractional order proportional integral derivative (FOPID) controller is designed to create the reference power trajectory and to conquer the uncertainties and external disturbances. A fractional nonlinear model was utilized to describe the nuclear reactor dynamic behaviour considering thermal-hydraulic effects. The controller parameters were tuned using optimization method in Matlab/Simulink. The FOPID controller was simulated using Matlab/Simulink and the controller performance was evaluated for Hard variation of the reference power and compared with that of integer order a proportional integral derivative (IOPID) controller by two models of fractional neutron point kinetic (FNPK) and classical neutron point kinetic (CNPK). Also, the FOPID controller robustness was appraised against the external disturbance and uncertainties. Simulation results showed that the FOPID controller has the faster response of the control attempt signal and the smaller tracking error with respect to the IOPID in tracking the reference power trajectory. In addition, the results demonstrated the ability of FOPID controller in disturbance rejection and exhibited the good robustness of controller against uncertainty.

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Copyright of Food & Machinery is the property of Food & Machinery Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the underwater environment, robust control algorithms are required to control autonomous underwater vehicles (AUVs) at high speed while preventing large nonlinearities and disturbances. Sliding mode control (SMC) is a well-known robust control theory and has been widely used not only in AUV control but also in systems such as industrial robots which have high nonlinearity in their system dynamics. However, SMC has the disadvantage of causing chattering on the control input, and it is difficult to apply this method to the control fins of an AUV system that cannot move its fins at high speed underwater. In this work, a design for a sliding mode control with sliding perturbation observer (SMCSPO) algorithm is applied to AUVs, and the simulation results under underwater disturbance conditions are discussed. From simulation using MATLAB, it is confirmed that AUV control using SMCSPO shows better trajectory tracking control performance without chattering than PID control. [ABSTRACT FROM AUTHOR]

To address the problems of mismatch, poor flexibility and low accuracy of ordinary manipulators in the complex special deflagration work process, this paper proposes a new five-degree-of-freedom (5-DOF) folding deflagration manipulator. Firstly, the overall structure of the explosion-expulsion manipulator is introduced. The redundant degrees of freedom are formed by the parallel joint axes of the shoulder joint, elbow joint and wrist pitching joint, which increase the flexibility of the mechanism. Aiming at a complex system with multiple degrees of freedom and strong coupling of the manipulator, the virtual joint is introduced, the corresponding forward kinematics model is established by D–H method, and the inverse kinematics solution of the manipulator is derived by analytical method. In the MATLAB platform, the workspace of the manipulator is analyzed by Monte Carlo pseudo-random number method. The quintic polynomial interpolation method is used to simulate the deflagration task in joint space. Finally, the actual prototype experiment is carried out using the data obtained by simulation. The trajectory planning using the quintic polynomial interpolation method can ensure the smooth movement of the manipulator and high accuracy of operation. Furthermore, the trajectory is basically consistent with the simulation trajectory, which can realize the work requirements of putting the object into the explosion-proof tank. The new 5-DOF folding deflagration manipulator designed in this paper has stable motion and strong robustness, which can be used for deflagration during the COVID-19 epidemic. [ABSTRACT FROM AUTHOR]

The substantial increase in the number of motor vehicles in recent years has caused many traffic safety problems and has aroused widespread concern. As the basis of intelligent vehicle environment perception and a necessary condition for realizing the functions of assisted driving system, traffic sign recognition is of great significance for realizing automatic driving of vehicles, improving intelligent transportation systems, and promoting the development of smart cities. This paper mainly identifies traffic signs, using histogram of gradient feature extraction method. The image is collected and preprocessed by a vision sensor. The color threshold segmentation method and morphological processing are used to reduce the interference of the background area and enhance the contour of the sign area. Finally, HOG method is used to collect the gradient of each pixel point in the cell unit or the direction histogram of the edge to identify traffic signs. Through MATALB simulation, it is obtained that the HOG image feature extraction method has high accuracy, small error and short recognition time, which shows the effectiveness of the algorithm. [ABSTRACT FROM AUTHOR]

For high - order process objects with time - tag in industrial production, due to the complex structure of the controller, it is difficult to implement the method of directly designing the controller and reducing the order of the traditional model. In addition, noise will interfere with the controller. The above factors lead to unsatisfactory results using these methods. To solve these problems, the identification method based on step response is adopted in this study. By analyzing the input and output data of the step response of the object, a second - order plant with dead Lime model is established. The advantage of genetic algorithm to adapt the global search ability are used lo optimize the static gain, time constant and pure hysteresis coefficient, so as to perform accurate model identification of high - order time - delay objects. MATLAB simulation results show that the proposed method has the advantages of high accuracy, strong robustness and wide applicability. Using this method to identify the model in the text under the unit step input signal, the ITAE indicators are 18. 138 5, 6. 271 5 and 167. 889 2, respectively. [ABSTRACT FROM AUTHOR]

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Photovoltaic power generation system is easy to be affected by the environment and load changes, which will generate frequency and power fluctuations in the process of grid connection. The traditional PI control method is slow in response and poor in stability. To solve this problem, a new robust droop control design method is proposed in this study. An integral sliding mode controller is designed in the double closed - loop current inner loop control structure of bi - directional interconnected converter. The designed controller can not only suppress the voltage and frequency fluctuation of photovoltaic power generation system in the process of grid connection, but also ensure the stability of power system in different environmental conditions. The simulation results in MATLAB/Simulink show that the new robust droop control method is faster than the traditional PI control, and the fluctuation amplitude is reduced by nearly half, which ensures the continuous and stable operation of the grid after the photovoltaic power generation system is connected to the grid. [ABSTRACT FROM AUTHOR]

Many factors determine the efficient operation of a photovoltaic cell. These factors can be the intensity and spectral composition of illumination, the surface temperature, the ambient temperature, and the amount contaminations in the air and on the surface of the cells. The aim of the present study is to describe the effect of temperature gradient on the voltage and amperage changes, as well as the power output of a commercial solar cell through experimental methods and numerical simulations performed in MATLAB. The transient temperature investigations have allowed better understanding the time-dependent behavior of a solar cell under constant intensity illumination. Measurements prove that an increase in the surface temperature of the solar cell significantly reduces its performance. Measurements performed with the solar simulator show good conformity with simulated results. [ABSTRACT FROM AUTHOR]

The communication system of a microgrid can transfer the information of electricity price, power consumption and so on between users and the control centre. This capability is of great significance to improve the efficiency and sustainability of power facilities. In this paper, a bidirectional DC–AC converter topology is proposed to achieve the composite transmission of power and signals in microgrids. Since the transmitted signals are modulated by power switches of converters and integrated into the currents, the cost of signal couplers can be saved and the circuit structure can be simplified. In order to verify the feasibility of the proposed method, a simulation model of the proposed converter is implemented in MATLAB/Simulink. With the power supply frequency of 50 Hz, when the converter operates in the inverter mode and rectifier mode, the data transmission rate can reach 120 bit/s and 48 bit/s, respectively.

Air conditioners, which have become the most widely used cooling system, have already been employed in both household and commercial environments. Automation in air conditioning is a very complex and demanding task today. When a sensor in an automatic human detection air conditioner detects the motion and activity of people, it will automatically turn on and set the temperature accordingly. However, in situations in which there are no humans around or in which human presence is unstable for an extended period, energy and power are wasted. In this regard, a control system was created utilising a Neutrosophic logic controller to regulate the AC temperature to a specific level by reducing the compressor and fan speeds without considering other parameters. Since neutrosophic logic handles the truth, ambiguity, and untruth of people in a closed environment, a more intelligent air-conditioning system is created by the suggested approach. As a result, massive quantities of energy savings are achieved. To accomplish the desired outcome, a MATLAB simulation is applied.

Copyright of Information & Control is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The conceptually new approach based on the logarithmic norm to design of robust adaptive state‐feedback controller for linear time‐varying (LTV) systems under system's modeling uncertainty and nonlinear external disturbances is proposed. This controller, in the special cases when the control matrix of the system is invertible, makes every LTV system globally asymptotically insensitive to the external disturbances regardless how large these are, in the sense, that all solutions of the controlled system converge to zero as t → ∞. The effectiveness of the proposed approach is illustrated by the design of the crane control system. [ABSTRACT FROM AUTHOR]

Copyright of Light Industry Machinery is the property of Light Industry Machinery Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The proposed study provides a solution of the inverse and forward kinematic problems and workspace analysis for a five-degree-of-freedom parallel–serial manipulator, in which the parallel kinematic chain is made in the form of a tripod and the serial kinematic chain is made in the form of two carriages displaced in perpendicular directions. The proposed manipulator allows to realize five independent movements—three translations and two rotations motion pattern (3T2R). Analytical relationships between the coordinates of the end-effector and five controlled movements provided by manipulator's drives (generalized coordinates) were determined. The approach of reachable workspace calculation was defined with respect to available design constraints of the manipulator based on the obtained algorithms of the inverse and forward kinematics. Case studies are considered based on the obtained algorithms of inverse and forward kinematics. For the inverse kinematic problem, the solution is obtained in accordance with the given laws of position and orientation change of the end-effector, corresponding to the motion along a spiral-helical trajectory. For the forward kinematic problem, various assemblies of the manipulator are obtained at the same given values of the generalized coordinates. An example of reachable workspace designing finalizes the proposed study. Dimensions and extreme values of the end-effector orientation angles are calculated. [ABSTRACT FROM AUTHOR]

Copyright of Light Industry Machinery is the property of Light Industry Machinery Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The P-U curve of photovoltaic arrays (PVAs) has multi-peak characteristics under uneven illumination environments, and the maximum power point tracking (MPPT) strategy for the single peak may fail. An improved Fibonacci search algorithm is proposed to carry out MPPT of photovoltaic arrays under uniform illumination or light mutation. A multiple-interval search algorithm based on a circuit analysis method is presented for different topology arrays and illumination distributions. The series array analysis adopts the current analysis method, the parallel array analysis adopts the voltage analysis method, and the series and parallel array analysis adopts the current and voltage analysis method; then, the output control volume is determined, and the search interval is divided. The search steps in the Fibonacci method and the real-time changes of parameters in the optimization process can be observed by MATLAB simulation. Experimental results show that the algorithm uses less computation time and small area search instead of global search.

This paper presents a battery model applied to dynamic simulation software. The simulation model uses only the battery State-Of-Charge (SOC) as a state variable in order to avoid the algebraic loop problem. It is shown that this model, composed of a controlled voltage source in series with a resistance, can accurately describe the lithium titanate battery discharge process. The model’s parameters can be easily extracted from the manufacturer’s discharge curve. In this paper, it is actually applied to the self-starting system after the emergency stop of the EMU, the simulation model of the system is established by MATLAB/Simulink, and the ground test platform is used to simulate the actual working condition of EMU to complete the experimental verification. The results of both simulation and experiment proved that the scheme of battery self-shifting driven system is feasible and correct.

In the process of automatic control of high-pressure water jet cleaning equipment, there are two major problems，system response to real-time is poor and low reliability. In this paper, a special drive power structure is designed for the automatic control requirements of the device,which is considered from the perspective of DC drive power. Based on the structure of the conventional linear DC power supply，an improved buck converter is introduced . The simulation results show that the power supply has a faster output response and a higher power conversion efficiency,the output ripple is smaller. While the output voltage can be adjusted in real time.Which is improved the response to real-time and the reliability in a certain extent ,it can be better meet the jet cleaning equipment driver needs.

BACKGROUND: Combined infrared (CIR) and convective drying is a promising technology in dehydrating heat‐sensitive foods, such as fruits and vegetables. This novel thermal drying method, which involves the application of infrared energy and hot air during a drying process, can drastically enhance energy efficiency and improve overall product quality at the end of the process. Understanding the dynamics of what goes on inside the product during drying is important for further development, optimization, and upscaling of the drying method. In this study, a multiphase porous media model considering liquid water, gases, and solid matrix was developed for the CIR and hot‐air drying (HAD) of sweet potato slices in order to capture the relevant physics and obtain an in‐depth insight on the drying process. The model was simulated using Matlab with user‐friendly graphical user interface for easy coupling and faster computational time. RESULTS: The gas pressure for CIR‐HAD was higher centrally and decreased gradually towards the surface of the product. This implies that drying force is stronger at the product core than at the product surface. A phase change from liquid water to vapour occurs almost immediately after the start of the drying process for CIR‐HAD. The evaporation rate, as expected, was observed to increase with increased drying time. Evaporation during CIR‐HAD increased with increasing distance from the centreline of the sample surface. The simulation results of water and vapour flux revealed that moisture transport around the surfaces and sides of the sample is as a result of capillary diffusion, binary diffusion, and gas pressure in both the vertical and horizontal directions. The nonuniform dominant infrared heating caused the heterogeneous distribution of product temperature. These results suggest that CIR‐HAD of food occurs in a non‐uniform manner with high vapour and water concentration gradient between the product core and the surface. CONCLUSIONS: This study provides in‐depth insight into the physics and phase changes of food during CIR‐HAD. The multiphase model has the advantage that phase change and impact of CIR‐HAD operating parameters can be swiftly quantified. Such a modelling approach is thereby significant for further development and process optimization of CIR‐HAD towards industrial upscaling. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

For the undershoot caused by zeroes in the right-half plane of non-minimum phase systems, in order to suppress the undershoot and time lag of non-minimum phase systems, a two-step PID tuning method combined with the Smith predictive controller is proposed as a complex control algorithm. The algorithm achieves the effective of suppressing the undershoot of non-minimum phase systems by adjusting the pre-coefficient and PID parameters and applies it to the Smith predictive control structure to achieve the purpose of improving the system response time. The simulation model is established by using Simulink in MATLAB software to simulate a typical second-order control system. The simulation results show that the complex control algorithm eliminates the negative adjustment of the system, and verifies the effectiveness and robustness of the complex control algorithm. [ABSTRACT FROM AUTHOR]

This study presents a reduced switch three‐phase three‐level H‐Bridge‐based shunt active power filter (SAPF) for the mitigation of current harmonics, the reduction of current unbalance and the injection of reactive power. This recommended SAPF is developed by using two H‐bridge and two DC‐link capacitors. Compared to the conventional three‐level H Bridge‐based SAPF, the eight‐switch cascaded H bridge (ES‐CHB)‐based topology saves four semiconductor switches and one DC‐link capacitor. The ES‐CHB‐based SAPF saves the power electronic components and reduces voltage stress across each switch by introducing a small AC capacitor in series with coupling inductor in each phase. This LC circuit also reduces the harmonic stress of SAPF by tuning at the sixth order of current harmonics. The only drawback of the suggested SAPF is the DC link voltage unbalances. To address this problem, a modified feedback control strategy is proposed in this study. The modified controller regulates the DC link voltage at the desired voltage and mitigates the DC link voltage unbalances, by using reactive power flow control and active power flow control, respectively. The performance of the suggested eight‐switch three‐level CHB‐based SAPF is evaluated through MATLAB simulation and experimentally verified through the hardware implementation. [ABSTRACT FROM AUTHOR]

To fully realize the advantages of AC-AC variable frequency speed regulation performance, based on the principle of pulse blocking AC-AC frequency conversion under the traditional voltage balance, a three-phase pulse blocking type AC-AC is proposed when the input voltage is unbalanced. Through the theoretical analysis of the chopping control after blocking, fully-controlled power devices are used, and the duty cycle expression corresponding to each interval is derived according to the area equivalent principle. The frequency conversion amplitude modulation of the output voltage under the condition of unbalanced input voltage is realized, which make the frequency conversion speed control system achieved the running effect when it is in equilibrium. Finally, the mathematical model of three-phase pulse blocking type variable frequency speed control system with unbalanced input voltage is established, and a semi-physical simulation platform is designed. The simulation results are consistent with the results under equilibrium conditions, which proves the feasibility of theoretical analysis. [ABSTRACT FROM AUTHOR]

Generally, the controller designed by the fuzzy control algorithm is targeted to realize the MPPT control of the photovoltaic system. When the PV system or controller parameters change, there will be problems such as slow tracking speed, poor stability, and even tracking failure. In view of this, an MPPT algorithm based on variable universe fuzzy control is adopted in this paper. The fuzzy rule of controller is designed by using the tracking principle of conductance increment method to improve the universality of the controller. In addition, the algorithm introduces a scaling factor to implement the design of the variable universe to reduce the impact of changes in controller parameters on the tracking effect. The simulation model is built in MATLAB/Simulink, and the feasibility of the algorithm is verified. The simulation results show that the algorithm is nearly doubled in tracking speed compared with the conductance increment method. The simulation results show that the variable-domain fuzzy control method is nearly doubled in tracking speed compared with the conductance increment method. Besides, under the mismatch of the domain mismatch and the PV system model, the new method can better realize the MPPT control of the photovoltaic system compared with the conventional fuzzy control. [ABSTRACT FROM AUTHOR]

Natural gas, including biomethane, is a sustainable alternative fuel. Widening compressed natural gas applications by now is restricted by weakly developed infrastructure. Hygen Ltd. works on "hydraulic piston" technology for natural gas and biomethane compressing, storing, delivering and discharging the storage cylinders by means of an innovative hydraulic boosting technology. Designing of the Vehicle Fuelling Appliance (VFA) demands to take into account thermodynamics and gas dynamics properties at fluid compression and motion. The present paper deals with theoretical characteristics and their link to test measurements regarding a particular VFA HYGEN+ Alpha prototype manufactured by Hygen Ltd. [ABSTRACT FROM AUTHOR]

Superconducting magnetic energy storage (SMES) system is one of the efficient pulsed power compensators. Its response to the load fluctuations is faster and competent. This study proposes a non‐linear dynamic evolution control (NDEC) approach for SMES system. The control approach is implemented to regulate the error of three‐phase compensating current and DC‐link voltage. The control functions required for voltage source inverter (VSI) and bi‐directional DC–DC converter of the SMES system are derived using the NDEC control approach. A proportional–integral (PI) controller is replaced by the NDEC in the inner loop of a traditional pulse‐width‐modulation control strategy of VSI for the quick response and effective energy exchange. The elementary idea of implementing NDEC is to govern the system dynamics by maintaining a zero‐error state irrespective of load uncertainties quickly. Detrimental high rating stress on the system due to pulsed power load is substantially reduced with the proposed NDEC strategy. Source current is maintained almost balanced and harmonic‐free in order to ensure a quality and reliable supply to surrounding loads. The variation in source current is drastically reduced from 260 to 6% using the proposed system. Moreover, a comparative study between PI and NDEC‐based control scheme is presented using MATLAB simulation and experimental results. [ABSTRACT FROM AUTHOR]

Copyright of Information & Control is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The vibration type blueberry picker is to separate the branches of blueberry by vibrating the lateral branches of blueberry to produce forced force. Therefore, the stress model of blueberry lateral branches was established to einalyze the axial and longitudinal vibration of bluebeny lateral branches. Based on the undamped model, the vibration response of lateral branches and the forced force of fruit were deduced. Through MATLAB simulation analysis, the simulation results of vibration response and forced force in different co¬ordinates are obtained. Through the analysis of the simulation results, it is found that the axial force is less than the radial force, and the radial force is the key factor leading to fruit abscission, and the amplitudes of different positions of the same blueberry lateral branch are almost the same, so the bluebeny picker is designed based on this theory. Through the field experiment of the bluebeny picker, the efficiency of the machine is 10.6 times that of the human, which provides reference for the follow - up research [ABSTRACT FROM AUTHOR]

Copyright of Journal of Test & Measurement Technology is the property of Publishing Center of North University of China and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aiming at the requirements of the general experimental platform of the robot laboratory，the three-dimensional model of SCARA robot with four degrees of freedom was established in SolidWorks environment，and the mechanical body of SCARA robot was manufactured. The transmission scheme，mechanical structure design and kinematics analysis of SCARA robot were studied. On this basis，the workspace calculation of robot was completed based on Monte Carlo method，and the kinematics model of SCARA robot was established based on d-h parameter method，and the forward and reverse kinematics equations of robot were analyzed. At last，Matlab motion simulation analysis was carried out on SCARA robot，and the results of variation of each joint variable and simulation trajectory comparison were obtained. The results show that the four degrees of freedom SCARA robot transmission scheme and the feasibility of the mechanical structure design and the correctness of the robot kinematics model are verified，robot end actuators can accurately through a given sampling points，the variation of joint variables is consistent with the result of working space calculation，the robot to the establishment of the general experimental platform has important significance. [ABSTRACT FROM AUTHOR]

In the underwater environment, robust control algorithms are required to control autonomous underwater vehicles (AUVs) at high speed while preventing large nonlinearities and disturbances. Sliding mode control (SMC) is a well-known robust control theory and has been widely used not only in AUV control but also in systems such as industrial robots which have high nonlinearity in their system dynamics. However, SMC has the disadvantage of causing chattering on the control input, and it is difficult to apply this method to the control fins of an AUV system that cannot move its fins at high speed underwater. In this work, a design for a sliding mode control with sliding perturbation observer (SMCSPO) algorithm is applied to AUVs, and the simulation results under underwater disturbance conditions are discussed. From simulation using MATLAB, it is confirmed that AUV control using SMCSPO shows better trajectory tracking control performance without chattering than PID control.

Aiming at the designed 5-DOF manipulator,the forward kinematics model is established by using D-H method,and the closed expression of inverse kinematics is obtained by using the inverse transformation method and geometry method. By solving the inverse solution of the path points on the target trajectory,the inverse kinematics simulation is carried out by MATLAB. The two groups of the inverse solution are planed trajectory respectively,and the same trajectory is obtained,the relationship and its correctness between the kinematics equation of the joint angle is verified. On this basis,the polynomial fitting of a set of inverse solutions satisfying the joint angle range is carried out,and adopted sectional fitting method to reduce the degree of polynomial and the error,the analytical expression of the joint variable about the time t is obtained,the fitting result is accurate,achieves real-time control of the input gear easily. The method in a mechanism simulation is verified by Solid Works,the correctness of the analytical expression is proved.

To address the problems of mismatch, poor flexibility and low accuracy of ordinary manipulators in the complex special deflagration work process, this paper proposes a new five-degree-of-freedom (5-DOF) folding deflagration manipulator. Firstly, the overall structure of the explosion-expulsion manipulator is introduced. The redundant degrees of freedom are formed by the parallel joint axes of the shoulder joint, elbow joint and wrist pitching joint, which increase the flexibility of the mechanism. Aiming at a complex system with multiple degrees of freedom and strong coupling of the manipulator, the virtual joint is introduced, the corresponding forward kinematics model is established by D–H method, and the inverse kinematics solution of the manipulator is derived by analytical method. In the MATLAB platform, the workspace of the manipulator is analyzed by Monte Carlo pseudo-random number method. The quintic polynomial interpolation method is used to simulate the deflagration task in joint space. Finally, the actual prototype experiment is carried out using the data obtained by simulation. The trajectory planning using the quintic polynomial interpolation method can ensure the smooth movement of the manipulator and high accuracy of operation. Furthermore, the trajectory is basically consistent with the simulation trajectory, which can realize the work requirements of putting the object into the explosion-proof tank. The new 5-DOF folding deflagration manipulator designed in this paper has stable motion and strong robustness, which can be used for deflagration during the COVID-19 epidemic.

This paper evaluates the possibility of deorbiting a launch vehicle upper-stage at end-of-mission from low Earth orbit, by using an additional propulsion system as a means of achieving deorbiting and complying with the “25 years” mitigation regulation. The deorbiting performances of chemical and electrical propulsion are analyzed through a MATLAB code which integrates orbital perturbations such as gravitational acceleration, atmospheric drag and rocket engine/motor thrust. Additionally, the research is placed within a body of similar papers concerned with deorbiting by means of propulsion, by performing a state of the art study.

To overcome the staircase effects and simultaneously avoid edge blurring, here the authors proposed a novel algorithm of adaptive fourth-order partial differential equation (PDE) for image smoothing. The proposed method is based on You and Kaveh (YK) model that first performs a pre-processing using coherence-enhancing diffusion filter before the smoothing. Then, the authors select an adaptive edge-stopping function founded on the Tansig function to effectively remove the noise and insignificant details without destruction of important edges and textures in the image. MATLAB simulation results validate the efficiency of the proposed model quantitatively and visually, when compared with other state-of-the-art methods.

When the path planning is carried out for the traditional ant colony algorithm, the convergence speed is slow and it is easy to fall into the “self-locking”, and it is not easy to find the optimal path. A fusion ant colony-A* algorithm is proposed to solve the problem. The evaluation function of A* algorithm is introduced to improve and adjust the heuristic function and pheromone update mode of traditional ant colony algorithm, and reduce the possibility of “self-locking”, so that the optimal path can be quickly found. Finally, experiments are carried out on MATLAB simulation software. The experimental results show that the proposed algorithm improves the convergence speed by nearly 40%, and the optimal paths in environmental models 1 and 2 are 35.670 6 m and 29.799 0 m better than the 39.799 0 m and 32.213 2 m of the ant colony algorithm. [ABSTRACT FROM AUTHOR]