Pub Date : 2022-06-23DOI: 10.1080/21642583.2022.2079572
Wenbin Yang, Danqing Li
This paper is concerned with a prey–predator system involving herd behaviour and strong Allee effect. First, the local stability analysis of all the possible equilibrium points are investigated. Second, the existence of Hopf bifurcation around the unique positive equilibrium are carried out. Finally, this paper is ended with a numerical simulation to understand the dynamics of the system. As it turns out that the ‘Allee effect constant’ plays a very important role in biological invasion mechanism, such as controlling and preventing biological invasion or invading successfully.
{"title":"Dynamics analysis and numerical implementations of a diffusive predator–prey model with herd behaviour and Allee effect","authors":"Wenbin Yang, Danqing Li","doi":"10.1080/21642583.2022.2079572","DOIUrl":"https://doi.org/10.1080/21642583.2022.2079572","url":null,"abstract":"This paper is concerned with a prey–predator system involving herd behaviour and strong Allee effect. First, the local stability analysis of all the possible equilibrium points are investigated. Second, the existence of Hopf bifurcation around the unique positive equilibrium are carried out. Finally, this paper is ended with a numerical simulation to understand the dynamics of the system. As it turns out that the ‘Allee effect constant’ plays a very important role in biological invasion mechanism, such as controlling and preventing biological invasion or invading successfully.","PeriodicalId":46282,"journal":{"name":"Systems Science & Control Engineering","volume":"10 1","pages":"572 - 582"},"PeriodicalIF":4.1,"publicationDate":"2022-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46298153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-23DOI: 10.1080/21642583.2022.2091060
Guanyu Chen, Q. Wang, Xiang Li, Yanyun Zhang
As one of the important parts of Neural Network, activation function plays a very important role in model training in Neural Network. In this paper, the status quo, advantages and disadvantages of the existing common activation functions are analysed, and a new activation function is proposed and applied to target detection. To test the performance of the new activation function, this paper compares it with the ReLU activation functions on a variety of Neural Networks and data sets, and not only analyses the performance of the activation function itself but also verifies the effectiveness of the activation function in target detection.
{"title":"Target detection based on a new triple activation function","authors":"Guanyu Chen, Q. Wang, Xiang Li, Yanyun Zhang","doi":"10.1080/21642583.2022.2091060","DOIUrl":"https://doi.org/10.1080/21642583.2022.2091060","url":null,"abstract":"As one of the important parts of Neural Network, activation function plays a very important role in model training in Neural Network. In this paper, the status quo, advantages and disadvantages of the existing common activation functions are analysed, and a new activation function is proposed and applied to target detection. To test the performance of the new activation function, this paper compares it with the ReLU activation functions on a variety of Neural Networks and data sets, and not only analyses the performance of the activation function itself but also verifies the effectiveness of the activation function in target detection.","PeriodicalId":46282,"journal":{"name":"Systems Science & Control Engineering","volume":"10 1","pages":"629 - 635"},"PeriodicalIF":4.1,"publicationDate":"2022-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41932291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-06DOI: 10.1080/21642583.2022.2082579
Jili Zhou, Q. Yang, Huijuan Meng, D. Gao
In the marine environment, there are problems such as complex background and low illumination, resulting in poor picture quality, and the aggregation of small targets and multiple targets brings difficulties to target recognition. In order to improve the accuracy of marine target detection, the image enhancement and improved YOLOv4 algorithm are used to identify marine organisms. Firstly, aiming at the problems of image blur, some of the images are enhanced with the multi-scale retinex with colour restoration (MSRCR) enhancement algorithm so that the image is clearer and it is easier to extract features. Secondly, Mosaic augmentation is added to YOLOv4 to enrich the data set and increase network robustness. Then the Spatial Pyramid Pooling (SPP) module of YOLOv4 is improved by changing the size of the pooling core, which increases the range of feature extraction and improves the detection capabilities, and its mAP value reaches 97.06%. The experimental results show that the detection accuracy of the image enhancement and improved YOLOv4 algorithm is 7.16% higher than that of the original algorithm. And the improved YOLOv4 algorithm is improved in average precision and recall rate compared with other algorithms, which verifies the effectiveness of the algorithm.
在海洋环境中,存在背景复杂、照度低等问题,导致图像质量差,小目标和多目标的聚集给目标识别带来困难。为了提高海洋目标检测的精度,采用图像增强和改进的YOLOv4算法对海洋生物进行识别。首先,针对图像模糊的问题,对部分图像采用多尺度retinex with colour restoration (MSRCR)增强算法进行增强,使图像更清晰,更容易提取特征;其次,在YOLOv4中加入了马赛克增强,丰富了数据集,提高了网络的鲁棒性。然后通过改变池化核的大小对YOLOv4的空间金字塔池化(SPP)模块进行改进,增加了特征提取的范围,提高了检测能力,其mAP值达到97.06%。实验结果表明,图像增强和改进后的YOLOv4算法的检测精度比原算法提高了7.16%。与其他算法相比,改进后的YOLOv4算法在平均精度和召回率方面都有提高,验证了算法的有效性。
{"title":"An underwater target recognition method based on improved YOLOv4 in complex marine environment","authors":"Jili Zhou, Q. Yang, Huijuan Meng, D. Gao","doi":"10.1080/21642583.2022.2082579","DOIUrl":"https://doi.org/10.1080/21642583.2022.2082579","url":null,"abstract":"In the marine environment, there are problems such as complex background and low illumination, resulting in poor picture quality, and the aggregation of small targets and multiple targets brings difficulties to target recognition. In order to improve the accuracy of marine target detection, the image enhancement and improved YOLOv4 algorithm are used to identify marine organisms. Firstly, aiming at the problems of image blur, some of the images are enhanced with the multi-scale retinex with colour restoration (MSRCR) enhancement algorithm so that the image is clearer and it is easier to extract features. Secondly, Mosaic augmentation is added to YOLOv4 to enrich the data set and increase network robustness. Then the Spatial Pyramid Pooling (SPP) module of YOLOv4 is improved by changing the size of the pooling core, which increases the range of feature extraction and improves the detection capabilities, and its mAP value reaches 97.06%. The experimental results show that the detection accuracy of the image enhancement and improved YOLOv4 algorithm is 7.16% higher than that of the original algorithm. And the improved YOLOv4 algorithm is improved in average precision and recall rate compared with other algorithms, which verifies the effectiveness of the algorithm.","PeriodicalId":46282,"journal":{"name":"Systems Science & Control Engineering","volume":"10 1","pages":"590 - 602"},"PeriodicalIF":4.1,"publicationDate":"2022-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43633692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-27DOI: 10.1080/21642583.2022.2079021
Jun Zhao, Heng-jie Liu, Xingzhong Xiong, Guoping Liu, Hang Yang
A modularized output formation tracking control for mixed-order multi-agent systems is investigated. The multi-agent systems are composed of first-order and second-order integrators. The stability and formation tracking performance are analysed theoretically by the mathematical induction method. Finally, the effectiveness of the proposed modularized output control protocol is verified by simulation examples.
{"title":"A novel modularized formation tracking control for mixed-order discrete-time multi-agent systems","authors":"Jun Zhao, Heng-jie Liu, Xingzhong Xiong, Guoping Liu, Hang Yang","doi":"10.1080/21642583.2022.2079021","DOIUrl":"https://doi.org/10.1080/21642583.2022.2079021","url":null,"abstract":"A modularized output formation tracking control for mixed-order multi-agent systems is investigated. The multi-agent systems are composed of first-order and second-order integrators. The stability and formation tracking performance are analysed theoretically by the mathematical induction method. Finally, the effectiveness of the proposed modularized output control protocol is verified by simulation examples.","PeriodicalId":46282,"journal":{"name":"Systems Science & Control Engineering","volume":"10 1","pages":"583 - 589"},"PeriodicalIF":4.1,"publicationDate":"2022-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46762837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-17DOI: 10.1080/21642583.2022.2074168
Shanwen Zhang, Rongzhi Jing, Xiaoli Shi
Crop pest insects seriously affect yield and quality of crops, and pesticide control methods cause severe environmental pollution, which has inextricably influenced people’s daily lives. Crop pest identification in the field is crucial components of pest control. It is much more complex than generic object recognition due to the apparent differences in the same pest species in the field with various shapes, colours, sizes and complex background. A crop pest recognition method is proposed based on a modified capsule network (MCapsNet). In MCapsNet, a capsule network is used to improve the traditional convolutional neural network (CNN), and an attention module is introduced to capture the most important classification features and speed up the network training. The experimental results on a pest image dataset validate that the proposed method is effective and feasible in classifying various types of insects in field crops and can be implemented in the agriculture sector for crop protection.
{"title":"Crop pest recognition based on a modified capsule network","authors":"Shanwen Zhang, Rongzhi Jing, Xiaoli Shi","doi":"10.1080/21642583.2022.2074168","DOIUrl":"https://doi.org/10.1080/21642583.2022.2074168","url":null,"abstract":"Crop pest insects seriously affect yield and quality of crops, and pesticide control methods cause severe environmental pollution, which has inextricably influenced people’s daily lives. Crop pest identification in the field is crucial components of pest control. It is much more complex than generic object recognition due to the apparent differences in the same pest species in the field with various shapes, colours, sizes and complex background. A crop pest recognition method is proposed based on a modified capsule network (MCapsNet). In MCapsNet, a capsule network is used to improve the traditional convolutional neural network (CNN), and an attention module is introduced to capture the most important classification features and speed up the network training. The experimental results on a pest image dataset validate that the proposed method is effective and feasible in classifying various types of insects in field crops and can be implemented in the agriculture sector for crop protection.","PeriodicalId":46282,"journal":{"name":"Systems Science & Control Engineering","volume":"10 1","pages":"552 - 561"},"PeriodicalIF":4.1,"publicationDate":"2022-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49410638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-17DOI: 10.1080/21642583.2022.2075950
M. Füllsack
We trained a long-short-term-memory (LSTM)-neural network on time series generated with an agent-based model that was designed to differentiate the drivers of its dynamics into external and internal forces, with the internal ones stemming from neighbourhood interaction considered as ‘social’ influence. The trained LSTM proved capable of predicting changes in the dynamics of time series from systems prone to critical transitions. The probability of the assessment – i.e. the ‘certainty’ of the LSTM for its prediction – thus can be used to indicate qualitative changes in a system's behaviour. In many cases, these certainties announce imminent state changes earlier and also more clearly than the set of statistical methods, which is suggested for predicting critical transitions under the term early warning signals.
{"title":"LSTM-certainty as early warning signal for critical transitions","authors":"M. Füllsack","doi":"10.1080/21642583.2022.2075950","DOIUrl":"https://doi.org/10.1080/21642583.2022.2075950","url":null,"abstract":"We trained a long-short-term-memory (LSTM)-neural network on time series generated with an agent-based model that was designed to differentiate the drivers of its dynamics into external and internal forces, with the internal ones stemming from neighbourhood interaction considered as ‘social’ influence. The trained LSTM proved capable of predicting changes in the dynamics of time series from systems prone to critical transitions. The probability of the assessment – i.e. the ‘certainty’ of the LSTM for its prediction – thus can be used to indicate qualitative changes in a system's behaviour. In many cases, these certainties announce imminent state changes earlier and also more clearly than the set of statistical methods, which is suggested for predicting critical transitions under the term early warning signals.","PeriodicalId":46282,"journal":{"name":"Systems Science & Control Engineering","volume":"10 1","pages":"562 - 571"},"PeriodicalIF":4.1,"publicationDate":"2022-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44472045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-13DOI: 10.1080/21642583.2022.2040059
Hai-Bo Gu, Jianhua Sun, H. Imani
In this paper, a new method is presented for synchronization between two fractional order delayed chaotic systems, while there is uncertainty on the models and external disturbances enter the systems at the same time. The considered delay in the fractional order system is unspecified and varied with time, and of course it is present in different forms in master and slave systems. External disturbances enter the master–slave systems in a finite manner, albeit with an undetermined upper bound, and uncertainty is present in the nonlinear functions of chaotic systems. The goal of synchronizing a particular class of master–slave chaotic systems is achieved through a combination of adaptive and sliding mode techniques. The sliding mode method has been used to cover the effects of uncertainties and delay functions, and an adaptive method has been applied to ensure the stability of the proposed synchronization technique, disturbance upper bound estimation and overcoming the effects of delay variability. A practical example of the innovative method is simulated in MATLAB environment and the obtained results confirm the optimal efficiency of the proposed synchronization method.
{"title":"A robust control scheme for synchronizing fractional order disturbed chaotic systems with uncertainty and time-varying delay","authors":"Hai-Bo Gu, Jianhua Sun, H. Imani","doi":"10.1080/21642583.2022.2040059","DOIUrl":"https://doi.org/10.1080/21642583.2022.2040059","url":null,"abstract":"In this paper, a new method is presented for synchronization between two fractional order delayed chaotic systems, while there is uncertainty on the models and external disturbances enter the systems at the same time. The considered delay in the fractional order system is unspecified and varied with time, and of course it is present in different forms in master and slave systems. External disturbances enter the master–slave systems in a finite manner, albeit with an undetermined upper bound, and uncertainty is present in the nonlinear functions of chaotic systems. The goal of synchronizing a particular class of master–slave chaotic systems is achieved through a combination of adaptive and sliding mode techniques. The sliding mode method has been used to cover the effects of uncertainties and delay functions, and an adaptive method has been applied to ensure the stability of the proposed synchronization technique, disturbance upper bound estimation and overcoming the effects of delay variability. A practical example of the innovative method is simulated in MATLAB environment and the obtained results confirm the optimal efficiency of the proposed synchronization method.","PeriodicalId":46282,"journal":{"name":"Systems Science & Control Engineering","volume":"10 1","pages":"528 - 538"},"PeriodicalIF":4.1,"publicationDate":"2022-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44891381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-11DOI: 10.1080/21642583.2022.2074169
Guang-yu Bao, Lifeng Ma, X. Yi
In this paper, the cooperative control of heterogeneous multi-agent systems (HMASs) subject to certain constraints are surveyed. First, HMASs are classified into two categories, namely, weak and strong HMASs, according to different cooperative behaviours. Then, control strategies are discussed for HMASs when facing different sorts of constraints imposed on the agent dynamics and on the communication networks. Subsequently, some latest results on the cooperative control subject to various kinds of constraints are summarized. Finally, conclusions are drawn, and several possible future research directions are pointed out.
{"title":"Recent advances on cooperative control of heterogeneous multi-agent systems subject to constraints: a survey","authors":"Guang-yu Bao, Lifeng Ma, X. Yi","doi":"10.1080/21642583.2022.2074169","DOIUrl":"https://doi.org/10.1080/21642583.2022.2074169","url":null,"abstract":"In this paper, the cooperative control of heterogeneous multi-agent systems (HMASs) subject to certain constraints are surveyed. First, HMASs are classified into two categories, namely, weak and strong HMASs, according to different cooperative behaviours. Then, control strategies are discussed for HMASs when facing different sorts of constraints imposed on the agent dynamics and on the communication networks. Subsequently, some latest results on the cooperative control subject to various kinds of constraints are summarized. Finally, conclusions are drawn, and several possible future research directions are pointed out.","PeriodicalId":46282,"journal":{"name":"Systems Science & Control Engineering","volume":"10 1","pages":"539 - 551"},"PeriodicalIF":4.1,"publicationDate":"2022-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49387948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-10DOI: 10.1080/21642583.2022.2074170
Jitai Liang
In this paper, the stability and stabilization problems of a class of impulsive switched linear systems with mode-dependent persistent dwell-time (MPDT) switching are investigated in continuous-time domain. The proposed switching law is more general, which not only covers the widely probed dwell-time (DT) and average dwell-time (ADT) as special cases but also extends the persistent dwell time (PDT) in the literature. By invoking novel modal partition time-dependent multiple Lyapunov-like functions, the stability criteria for the systems under MPDT switching in nonlinear settings are established as a first attempt, upon which the desired mode-dependent and semi-time-dependent (STD) stabilizing controllers for continuous-time impulsive switched linear systems are designed. It is demonstrated that the control performance is improved as both the length of admissible MPDT and the number of time partition segment are added. Finally, a numerical example is provided to illustrate the potential of the obtained theoretical results.
{"title":"Semi-time-dependent stabilization for a class of continuous-time impulsive switched linear systems","authors":"Jitai Liang","doi":"10.1080/21642583.2022.2074170","DOIUrl":"https://doi.org/10.1080/21642583.2022.2074170","url":null,"abstract":"In this paper, the stability and stabilization problems of a class of impulsive switched linear systems with mode-dependent persistent dwell-time (MPDT) switching are investigated in continuous-time domain. The proposed switching law is more general, which not only covers the widely probed dwell-time (DT) and average dwell-time (ADT) as special cases but also extends the persistent dwell time (PDT) in the literature. By invoking novel modal partition time-dependent multiple Lyapunov-like functions, the stability criteria for the systems under MPDT switching in nonlinear settings are established as a first attempt, upon which the desired mode-dependent and semi-time-dependent (STD) stabilizing controllers for continuous-time impulsive switched linear systems are designed. It is demonstrated that the control performance is improved as both the length of admissible MPDT and the number of time partition segment are added. Finally, a numerical example is provided to illustrate the potential of the obtained theoretical results.","PeriodicalId":46282,"journal":{"name":"Systems Science & Control Engineering","volume":"10 1","pages":"517 - 527"},"PeriodicalIF":4.1,"publicationDate":"2022-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42547553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-10DOI: 10.1080/21642583.2022.2063201
Quang Dan Le, Hee-Jun Kang
In this paper, we propose the estimation of contact force in a collaborative robot without explicit force-sensing based on the adaptive third-order sliding mode observer. An adaptive third-order sliding mode observer was designed to estimate the contact force based only on the position measurement. The information from the observer was used for admittance control and emergent stop control when the robot interacts with a human. The experimental results with the emergent stop control and admittance control, using the proposed contact force estimation for the 3-DOF AT2-FARA robot manipulator, illustrate the capability of the proposed system in real-world application.
{"title":"Implementation of sensorless contact force estimation in collaborative robot based on adaptive third-order sliding mode observer","authors":"Quang Dan Le, Hee-Jun Kang","doi":"10.1080/21642583.2022.2063201","DOIUrl":"https://doi.org/10.1080/21642583.2022.2063201","url":null,"abstract":"In this paper, we propose the estimation of contact force in a collaborative robot without explicit force-sensing based on the adaptive third-order sliding mode observer. An adaptive third-order sliding mode observer was designed to estimate the contact force based only on the position measurement. The information from the observer was used for admittance control and emergent stop control when the robot interacts with a human. The experimental results with the emergent stop control and admittance control, using the proposed contact force estimation for the 3-DOF AT2-FARA robot manipulator, illustrate the capability of the proposed system in real-world application.","PeriodicalId":46282,"journal":{"name":"Systems Science & Control Engineering","volume":"10 1","pages":"507 - 516"},"PeriodicalIF":4.1,"publicationDate":"2022-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48446426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}