To ensure the stable driving of tracked robots in a complex farmland environment,an adaptive backstepping control method for tracked robots was proposed based on real-time slip parameter estimation.According to the ki...To ensure the stable driving of tracked robots in a complex farmland environment,an adaptive backstepping control method for tracked robots was proposed based on real-time slip parameter estimation.According to the kinematics analysis method,the kinematic model of the tracked robot was established,and then,its pose error differential equation was further obtained.On this basis,the trajectory tracking controller of the tracked robot was designed based on the backstepping control theory.Subsequently,according to the trajectory tracking error of the tracked robot,the back propagation neural network(BPNN)was used to adaptively adjust the control parameters in the backstepping controller,and the inputs of the BPNN are the trajectory tracking error xe,ye,θe.After that,the soft-switching sliding mode observer(SSMO)was designed to identify the slip parameters during the running of the tracked robot.And then the parameters were compensated into the adaptive backstepping controller to reduce the trajectory tracking error.The simulation results show that the proposed adaptive backstepping control method with SSMO can improve the accuracy of the trajectory tracking control of the tracked robot.Additionally,the designed SSMO can accurately estimate the slip parameters.展开更多
The objective of this paper is to study unsteady magneto hydrodynamic (MHD) free flow of viscoelastic fluid (Walter’s B) past an infinite vertical plate through porous medium. The temperature is assumed to be oscilla...The objective of this paper is to study unsteady magneto hydrodynamic (MHD) free flow of viscoelastic fluid (Walter’s B) past an infinite vertical plate through porous medium. The temperature is assumed to be oscillating with time. The solution obtained shows different profiles of effects of slip conditions on primary and secondary velocity. Also, the effects of various parameters on temperature, concentration, primary and secondary velocity profiles were presented graphically. The result indicated the secondary velocity is enhanced with increase in slip parameter. Primary velocity demonstrated opposite trend.展开更多
The current exploration focuses on the ethylene glycol(EG)based nanoliquid flow in a microchannel.The effectiveness of the internal heat source and linear radiation is reflected in the present investigation.The estima...The current exploration focuses on the ethylene glycol(EG)based nanoliquid flow in a microchannel.The effectiveness of the internal heat source and linear radiation is reflected in the present investigation.The estimation of suitable thermal conductivity model has affirmative impact on the convective heat transfer phenomenon.The examination is conceded with the nanoparticle aggregation demonstrated by the Maxwell-Bruggeman and Krieger-Dougherty models which tackle the formation of nanolayer.These models effectively describe the thermal conductivity and viscosity correspondingly.The dimensionless mathematical expressions are solved numerically by the Runge Kutta Fehlberg approach.A higher thermal field is attained for the Bruggeman model due to the formation of thermal bridge.A second law analysis is carried out to predict the sources of irreversibility associated with the thermal system.It is remarked that lesser entropy generation is obtained for the aggregation model.The entropy generation rate declines with the slip flow and the thermal heat flux.A notable enhancement in the Bejan number is attained by increasing the Biot number.It is established that the nanoparticle aggragation model exhibits a higher Bejan number in comparision with the usual flow model.展开更多
基金We acknowledge that this research was financially supported by the National Natural Science Foundation of China(No.51975256)China Postdoctoral Science Foundation Grant(2019M651962)+4 种基金earmarked fund for China Agriculture Research System CARS-12Jiangsu Agriculture Science and Technology Innovation Fund(JASTIF)CX(19)3083Jiangsu Province“Six Talent Peaks”innovative talent team(TD-GDZB-005)Key R&D plan of Zhenjiang industry prospect and common key technology(GZ2017001)A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(No.PAPD-2018-87).
文摘To ensure the stable driving of tracked robots in a complex farmland environment,an adaptive backstepping control method for tracked robots was proposed based on real-time slip parameter estimation.According to the kinematics analysis method,the kinematic model of the tracked robot was established,and then,its pose error differential equation was further obtained.On this basis,the trajectory tracking controller of the tracked robot was designed based on the backstepping control theory.Subsequently,according to the trajectory tracking error of the tracked robot,the back propagation neural network(BPNN)was used to adaptively adjust the control parameters in the backstepping controller,and the inputs of the BPNN are the trajectory tracking error xe,ye,θe.After that,the soft-switching sliding mode observer(SSMO)was designed to identify the slip parameters during the running of the tracked robot.And then the parameters were compensated into the adaptive backstepping controller to reduce the trajectory tracking error.The simulation results show that the proposed adaptive backstepping control method with SSMO can improve the accuracy of the trajectory tracking control of the tracked robot.Additionally,the designed SSMO can accurately estimate the slip parameters.
文摘The objective of this paper is to study unsteady magneto hydrodynamic (MHD) free flow of viscoelastic fluid (Walter’s B) past an infinite vertical plate through porous medium. The temperature is assumed to be oscillating with time. The solution obtained shows different profiles of effects of slip conditions on primary and secondary velocity. Also, the effects of various parameters on temperature, concentration, primary and secondary velocity profiles were presented graphically. The result indicated the secondary velocity is enhanced with increase in slip parameter. Primary velocity demonstrated opposite trend.
文摘The current exploration focuses on the ethylene glycol(EG)based nanoliquid flow in a microchannel.The effectiveness of the internal heat source and linear radiation is reflected in the present investigation.The estimation of suitable thermal conductivity model has affirmative impact on the convective heat transfer phenomenon.The examination is conceded with the nanoparticle aggregation demonstrated by the Maxwell-Bruggeman and Krieger-Dougherty models which tackle the formation of nanolayer.These models effectively describe the thermal conductivity and viscosity correspondingly.The dimensionless mathematical expressions are solved numerically by the Runge Kutta Fehlberg approach.A higher thermal field is attained for the Bruggeman model due to the formation of thermal bridge.A second law analysis is carried out to predict the sources of irreversibility associated with the thermal system.It is remarked that lesser entropy generation is obtained for the aggregation model.The entropy generation rate declines with the slip flow and the thermal heat flux.A notable enhancement in the Bejan number is attained by increasing the Biot number.It is established that the nanoparticle aggragation model exhibits a higher Bejan number in comparision with the usual flow model.
