A novel hybrid robust three-axis attitude control approach,namely HRTAC,is considered along with the well-known developments in the area of space systems,since there is a consensus among the related experts that the n...A novel hybrid robust three-axis attitude control approach,namely HRTAC,is considered along with the well-known developments in the area of space systems,since there is a consensus among the related experts that the new insights may be taken into account as decision points to outperform the available materials.It is to note that the traditional control approaches may generally be upgraded,as long as a number of modifications are made with respect to state-of-the-art,in order to propose high-precision outcomes.Regarding the investigated issues,the robust sliding mode finite-time control approach is first designed to handle three-axis angular rates in the inner control loop,which consists of the pulse width pulse frequency modulations in line with the control allocation scheme and the system dynamics.The main subject to employ these modulations that is realizing in association with the control allocation scheme is to be able to handle a class of overactuated systems,in particular.The proportional derivative based linear quadratic regulator approach is then designed to handle three-axis rotational angles in the outer control loop,which consists of the system kinematics that is correspondingly concentrated to deal with the quaternion based model.The utilization of the linear and its nonlinear terms,simultaneously,are taken into real consideration as the research motivation,while the performance results are of the significance as the improved version in comparison with the recent investigated outcomes.Subsequently,there is a stability analysis to verify and guarantee the closed loop system performance in coping with the whole of nominal referenced commands.At the end,the effectiveness of the approach considered here is highlighted in line with a number of potential recent benchmarks.展开更多
Rice precision hill-drop drilling technique in dry land uses fixed hill spacing to achieve orderly planting of crops and to attain good ventilating and day-lighting effects in rice fields.The technique is also benefic...Rice precision hill-drop drilling technique in dry land uses fixed hill spacing to achieve orderly planting of crops and to attain good ventilating and day-lighting effects in rice fields.The technique is also beneficial in improving root growth and root structure and in increasing lodging resistance.The high-yield record of Xinjiang Production and Construction Corp’s first division for three consecutive years shows that rice precision hill-drop drilling technique in dry land is one of the important directions to developed rice cultivating mechanization technology.To further improve the quality of rice precision hill-drop drilling machine for dry land,a single profiling,electro-hydraulic proportional real-time adjustment of system was developed according to the agronomic requirements.This machine can simultaneously finish various kinds of seedbed leveling,furrowing and seeding operations,as well as soil covering and pressing.Electro-hydraulic proportional speed regulation makes an AMESim simulation test and analyzes the stability and error of hydraulic adjusting planting distance.Bench testing was carried out on the metering device by simultaneously employing high speed photography technology and analyzing the relationship of the high speed of hill distance and seed charge height.Finally,machine trial was completed.The two-year field experiments of Xinjiang Production and Construction Corp showed that when the machine operation speed is 2.8-3.2 km/h,the sowing depth percent of pass is 75%or higher,the qualified rate of row spacing is 80%or more,the pass rate of row spacing is 90%or higher,and the quantity per hill is 75%or higher.This machine met the various indicators of hill sowing quality requirements.展开更多
Pneumatic proportional control servo regulator is the core component of a pneumatic-loading experimental system,which is very important in solving the overcharging problem.However,previous research on control of pneum...Pneumatic proportional control servo regulator is the core component of a pneumatic-loading experimental system,which is very important in solving the overcharging problem.However,previous research on control of pneumatic proportional regulator in a pneumatic-loading experimental system led to failure in analysis of the influence of opening error of the switch regulator because it did not analyze the regulator basic working principle and process.The traditional control method cannot fully solve the overcharging problem nor ensure adequate control performance of the regulator.After seriously studying the working principle and key mechanical parameters of the valve,a fuzzy parameter-adaptive controller is designed by introducing a linear mixture of the pressure and opening errors of the switch regulator to reduce pressure overshoot and optimize its control performance.According to the fuzzy-control strategy based on the working characteristics and mechanical parameters of the valve,the overshoot phenomenon of the pneumatic-loading system is solved,and the pressure overshoot is eliminated.The error of the output air pressure of the regulator is 1.24%,which is small.The adjustable pressure range of the regulator is 0.2–0.6 MPa.The maximum deviation is 0.012 MPa.The linearity of the case is 1.34%F.S.展开更多
文摘A novel hybrid robust three-axis attitude control approach,namely HRTAC,is considered along with the well-known developments in the area of space systems,since there is a consensus among the related experts that the new insights may be taken into account as decision points to outperform the available materials.It is to note that the traditional control approaches may generally be upgraded,as long as a number of modifications are made with respect to state-of-the-art,in order to propose high-precision outcomes.Regarding the investigated issues,the robust sliding mode finite-time control approach is first designed to handle three-axis angular rates in the inner control loop,which consists of the pulse width pulse frequency modulations in line with the control allocation scheme and the system dynamics.The main subject to employ these modulations that is realizing in association with the control allocation scheme is to be able to handle a class of overactuated systems,in particular.The proportional derivative based linear quadratic regulator approach is then designed to handle three-axis rotational angles in the outer control loop,which consists of the system kinematics that is correspondingly concentrated to deal with the quaternion based model.The utilization of the linear and its nonlinear terms,simultaneously,are taken into real consideration as the research motivation,while the performance results are of the significance as the improved version in comparison with the recent investigated outcomes.Subsequently,there is a stability analysis to verify and guarantee the closed loop system performance in coping with the whole of nominal referenced commands.At the end,the effectiveness of the approach considered here is highlighted in line with a number of potential recent benchmarks.
文摘Rice precision hill-drop drilling technique in dry land uses fixed hill spacing to achieve orderly planting of crops and to attain good ventilating and day-lighting effects in rice fields.The technique is also beneficial in improving root growth and root structure and in increasing lodging resistance.The high-yield record of Xinjiang Production and Construction Corp’s first division for three consecutive years shows that rice precision hill-drop drilling technique in dry land is one of the important directions to developed rice cultivating mechanization technology.To further improve the quality of rice precision hill-drop drilling machine for dry land,a single profiling,electro-hydraulic proportional real-time adjustment of system was developed according to the agronomic requirements.This machine can simultaneously finish various kinds of seedbed leveling,furrowing and seeding operations,as well as soil covering and pressing.Electro-hydraulic proportional speed regulation makes an AMESim simulation test and analyzes the stability and error of hydraulic adjusting planting distance.Bench testing was carried out on the metering device by simultaneously employing high speed photography technology and analyzing the relationship of the high speed of hill distance and seed charge height.Finally,machine trial was completed.The two-year field experiments of Xinjiang Production and Construction Corp showed that when the machine operation speed is 2.8-3.2 km/h,the sowing depth percent of pass is 75%or higher,the qualified rate of row spacing is 80%or more,the pass rate of row spacing is 90%or higher,and the quantity per hill is 75%or higher.This machine met the various indicators of hill sowing quality requirements.
基金supported by the China Postdoctoral Science Foundation(Grant No. 2019M660392)the Open Research Project of the State Key Laboratory of Media Convergence and Communication, Communication University of China (Grant No. SKLMCC2020KF002)the National Key Research and Development Project (Grant Nos. 2019YFC0121700,2021YFC0122502)
文摘Pneumatic proportional control servo regulator is the core component of a pneumatic-loading experimental system,which is very important in solving the overcharging problem.However,previous research on control of pneumatic proportional regulator in a pneumatic-loading experimental system led to failure in analysis of the influence of opening error of the switch regulator because it did not analyze the regulator basic working principle and process.The traditional control method cannot fully solve the overcharging problem nor ensure adequate control performance of the regulator.After seriously studying the working principle and key mechanical parameters of the valve,a fuzzy parameter-adaptive controller is designed by introducing a linear mixture of the pressure and opening errors of the switch regulator to reduce pressure overshoot and optimize its control performance.According to the fuzzy-control strategy based on the working characteristics and mechanical parameters of the valve,the overshoot phenomenon of the pneumatic-loading system is solved,and the pressure overshoot is eliminated.The error of the output air pressure of the regulator is 1.24%,which is small.The adjustable pressure range of the regulator is 0.2–0.6 MPa.The maximum deviation is 0.012 MPa.The linearity of the case is 1.34%F.S.
