Simulation of travelling performance and experimental research on heavy double crawlers on a soft ground

Guanyu Zhang,Xinhui Liu,Shuai Wang,Guoqiang Wang 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.2

This study analyzes resistances to sinking, steering bulldozer, steering friction, running, climbing, inertia, and wind and considered the offsetting effects of instantaneous center of speed and center of mass based on the sinkage method proposed by Bekker. The purpose of the analysis is to show the calculation method for the driving power of crawlers under different working conditions. The influence of several performance factors were analyzed to calculate the steering performance of a dumping machine with heavy double crawler. The performance factors include steering radius, offset mass, width-to-length ratio, crawler width wider than the interior and lateral, caterpillar gauge in crawler drive, drive power, and steering torque friction. These factors are involved in driving wheels at a crawler speed of 3.33 RPM. The law of operation for heavy crawlers under different working conditions is obtained by performing a real vehicle test. The results of this test are compared with the theoretical calculations to verify correctness. Such a test provides important theoretical basis for theoretical modeling and for analyzing the performance of large crawlers running on soft ground.

Chemical profiling and antioxidants screening from natural products: using CiNingJi as an example

Yida Zhang,Peiyan Zheng,Guanyu Yan,Yue Zhuo,Jian-lin Wu,Baoqing Sun 한국식품과학회 2022 Food Science and Biotechnology Vol.31 No.4

Natural products with good antioxidative prop- erties have been paid increased attention globally. How- ever, due to its chemical complexity, it is difficult to find out its antioxidative compounds. Herein, the chemical profiling and antioxidant capacity of CiNingJi (CNJ) were analyzed, as an example. By using UHPLC-Q-TOF/MS, a total of 82 compounds were tentatively deduced. Further- more, its free radical scavenging capacity was assessed by different in vitro spectrophotometric-based assays. The result showed that one ingredient, Rosa roxburghii, plays a critical role in its antioxidant activity. In addition, 18 potential antioxidants were screened out in CNJ by com- paring the difference of it with and without DPPH reaction. They were identified mainly as catechin, ellagic acid, kajiichigoside F1, and their derivatives or isomers. With the further quantification of major found antioxidants, our results may provide some knowledge on predicting the antioxidative compounds of natural products.

Aeroengine performance degradation prediction method considering operating conditions

Bang-Cheng Zhang,Shuo Gao,Zhong Zheng,Guanyu Hu 한국인터넷정보학회 2023 KSII Transactions on Internet and Information Syst Vol.17 No.9

It is significant to predict the performance degradation of complex electromechanical systems. Among the existing performance degradation prediction models, belief rule base (BRB) is a model that deal with quantitative data and qualitative information with uncertainty. However, when analyzing dynamic systems where observable indicators change frequently over time and working conditions, the traditional belief rule base (BRB) can not adapt to frequent changes in working conditions, such as the prediction of aeroengine performance degradation considering working condition. For the sake of settling this problem, this paper puts forward a new hidden belief rule base (HBRB) prediction method, in which the performance of aeroengines is regarded as hidden behavior, and operating conditions are used as observable indicators of the HBRB model to describe the hidden behavior to solve the problem of performance degradation prediction under different times and operating conditions. The performance degradation prediction case study of turbofan aeroengine simulation experiments proves the advantages of HBRB model, and the results testify the effectiveness and practicability of this method. Furthermore, it is compared with other advanced forecasting methods. The results testify this model can generate better predictions in aspects of accuracy and interpretability.

A Low-Computation Indirect Model Predictive Control for Modular Multilevel Converters

Wenzhong Ma,Peng Sun,Guanyu Zhou,Gulipali Sailijiang,Ziang Zhang,Yong Liu 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.2

The modular multilevel converter (MMC) has become a promising topology for high-voltage direct current (HVDC) transmission systems. To control a MMC system properly, the ac-side current, circulating current and submodule (SM) capacitor voltage are taken into consideration. This paper proposes a low-computation indirect model predictive control (IMPC) strategy that takes advantages of the conventional MPC and has no weighting factors. The cost function and duty cycle are introduced to minimize the tracking error of the ac-side current and to eliminate the circulating current. An optimized merge sort (OMS) algorithm is applied to keep the SM capacitor voltages balanced. The proposed IMPC strategy effectively reduces the controller complexity and computational burden. In this paper, a discrete-time mathematical model of a MMC system is developed and the duty ratio of switching state is designed. In addition, a simulation of an eleven-level MMC system based on MATLAB/Simulink and a five-level experimental setup are built to evaluate the feasibility and performance of the proposed low-computation IMPC strategy.

A Low-Computation Indirect Model Predictive Control for Modular Multilevel Converters

Ma, Wenzhong,Sun, Peng,Zhou, Guanyu,Sailijiang, Gulipali,Zhang, Ziang,Liu, Yong The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.2

The modular multilevel converter (MMC) has become a promising topology for high-voltage direct current (HVDC) transmission systems. To control a MMC system properly, the ac-side current, circulating current and submodule (SM) capacitor voltage are taken into consideration. This paper proposes a low-computation indirect model predictive control (IMPC) strategy that takes advantages of the conventional MPC and has no weighting factors. The cost function and duty cycle are introduced to minimize the tracking error of the ac-side current and to eliminate the circulating current. An optimized merge sort (OMS) algorithm is applied to keep the SM capacitor voltages balanced. The proposed IMPC strategy effectively reduces the controller complexity and computational burden. In this paper, a discrete-time mathematical model of a MMC system is developed and the duty ratio of switching state is designed. In addition, a simulation of an eleven-level MMC system based on MATLAB/Simulink and a five-level experimental setup are built to evaluate the feasibility and performance of the proposed low-computation IMPC strategy.

Electromechanical coupling modeling simulation and experimental study of crawler

Yanju Ji,Xueying Lv,Liu Zhang,Guanyu Zhang 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.2

The electromechanical coupling performance of crawler machinery is investigated. A dynamic equation of electromechanical coupling of crawler machinery is established under multi-typical working conditions. The variation in performance of electromechanical parameters during unstable operations over time is analyzed using the virtual prototype and electromechanical coupling model of crawler machinery. The correctness of the electromechanical coupling model is confirmed by comparing the theoretical analysis, virtual prototype simulation, and physical prototype results. This study provides accurate and valuable theoretical methods and fundamental knowledge to analyze the electromechanical and road driving performance as well as to develop and design a crawler machinery.

RESEARCH ON MILLIMETER WAVE RADAR SIMULATION MODEL FOR INTELLIGENT VEHICLE

Xin Li,Weiwen Deng,Sumin Zhang,Yaxin Li,Shiping Song,Shanshan Wang,Guanyu Wang 한국자동차공학회 2020 International journal of automotive technology Vol.21 No.2

Radar simulation models can effectively overcome the drawbacks of real vehicle experiment and speed up the development process of intelligent vehicle technologies based on millimeter wave radar via virtual testing. However, there are still many gaps between the radar model using in the virtual driving environment and the real radar. In this paper, a novel simulation model of intelligent vehicle millimeter wave radar is proposed. Based on the analysis of the real radar performance in typical application scenes, the radar model considers the mechanism and characteristics of the vehicle radar synthetically and a systematic radar modeling architecture with innovation is introduced. The highlights of this radar model include the design of the RCS simulation model for radar targets with both high accuracy and real-time performance, the establishment of the quantitative false alarm model, missed detection model and measurement error simulation model. Vast amounts of data collected by real vehicle radar are applied to fetch model parameters and verify the accuracy of the radar model. Simulation results show that the proposed model can reach both high reliability and computational efficiency.