针对高速自动驾驶车辆实时高精度的运动控制问题,提出一种上层为基于路径点Cost的路径点筛选器与基于横纵向轮胎力分析的速度规划器、下层为基于线性时变动力学模型预测的路径跟踪控制器与速度控制器的两层架构,并引入最小均方(Least Me...针对高速自动驾驶车辆实时高精度的运动控制问题,提出一种上层为基于路径点Cost的路径点筛选器与基于横纵向轮胎力分析的速度规划器、下层为基于线性时变动力学模型预测的路径跟踪控制器与速度控制器的两层架构,并引入最小均方(Least Mean Square,LMS)自适应状态估计器提升系统的抗噪性。路径点筛选器提升运算速度并减少筛选过程中的关键信息损失,速度规划器在安全行驶前提下生成最优速度曲线。路径跟踪控制器考虑跟踪偏差软约束,提升跟踪效果。LMS状态估计器基于在线矫正的动力学模型,对横摆角速度与横向速度在线估计。搭建dSPACE-TX2硬件在环仿真环境,在高速公路工况及双移线工况下对比所提出方案与传统运动跟踪控制。半实物仿真结果表明,所提出的运动控制架构提升了抗噪性能与21%的跟踪精度,且满足50 Hz高频控制的要求。展开更多
The reduction of water resources and soil fertility in Northeast China will have a requirement on higher working efficiency of agricultural soil-engaging components.The adhesion and resistance are main problems for so...The reduction of water resources and soil fertility in Northeast China will have a requirement on higher working efficiency of agricultural soil-engaging components.The adhesion and resistance are main problems for soil-engaging tillage components.However,the soil-burrowing or soil-digging animals give inspirations to resolve those problems.Their fair,claw,toe,textured surface and scales have functions of anti-adhesion or resistance reduction.Those results provide a way to realize the sustainable development of modern agriculture by developing novel biomimetic agricultural machinery systems with independent intellectual property rights to meet conservation tillage requirements in the Northern China region.Biological structures of some soil-burrowing or soil-digging animals,such as beetle,mole cricket,earthworm,mole,vole,pangolin,and snake,as well as their mechanisms of anti-adhesion or reducing resistance were reviewed in this paper.Bioinspired applications in Northeast China were also presented in the paper,including moldboard,subsoiler components,furrow opener,roller,and biomimetic rototilling-stubble-breaking blade.In addition,the existed problems in agricultural engineering and the future development trends were discussed.展开更多
A three-dimensional motion force tester for animal was used to measure the reaction forces of the feet of a Chinese toad (B. gargarizans) against a horizontal solid surface on which it crawled. The motion behavior of ...A three-dimensional motion force tester for animal was used to measure the reaction forces of the feet of a Chinese toad (B. gargarizans) against a horizontal solid surface on which it crawled. The motion behavior of the Chinese toad was recorded by a high-speed camera on line. The motor function of every foot was analyzed. It was found that the lateral force represents the control ability of side-to-side locomotion, controls the lateral movement, and maintains a stable state for the sustainable creeping gesture. The forefeet play the assistant role and the hind feet play the main role in driving. The normal force of the forefeet is significantly greater than that of the hind feet, so the forefeet play the main role in supporting the body and the hind feet play the assistant role. The normal force is significantly greater than the lateral force and the driving force as well. There is little change for the friction force and the support angle of the all four feet. The average value of the support angle is 70°–80°. The Chinese toad’s vola friction coefficient of the forefeet is less than that of the hind feet. The above results indicate that the difference in kinematics and the material characteristic of the contact skin of the Chinese toad. The results could be useful to the structure design and gait optimization of some robots.展开更多
In this study,maize stalk tegument separated from the maize pith was crushed to obtain the fiber.The cross-linking maize starch adhesives considering four main factors(water content,gelatinization temperature,NaOH as ...In this study,maize stalk tegument separated from the maize pith was crushed to obtain the fiber.The cross-linking maize starch adhesives considering four main factors(water content,gelatinization temperature,NaOH as gelatinization agent and Na2B4O7·10H2O as cross-linking agent)with three levels were prepared based on an orthogonal test scheme L9(34)in order to increase the water-resisting property and the bonding strength of the common maize starch adhesives.The bonding properties of maize starch adhesives were characterized using shearing strength under compression loading.Physical models of fiber reinforced composites were established according to the microstructure analysis of the four species of insects’elytra including Protaetia orentalis,Copris ochus Motschulsky,Anoplophora chinensis and Cytister bengalensis Aube,which will provide the biomimetic models for the biomimetic laminated boards.The maize stalk fiber biomimetic laminated boards were prepared based on the structural models of the elytra material.The flexural strength and flexural elastic modulus of the biomimetic boards were examined.The results showed that the flexural strengths of the single layer jute fiber,-reinforced maize stalk fiber boards and the dual layer jute fiber reinforced maize stalk fiber boards are higher than those of the common maize stalk fiber boards and the other three groups of jute fiber hybrid reinforced stalk fiber boards because of the biomimetic laminated design.展开更多
文摘针对高速自动驾驶车辆实时高精度的运动控制问题,提出一种上层为基于路径点Cost的路径点筛选器与基于横纵向轮胎力分析的速度规划器、下层为基于线性时变动力学模型预测的路径跟踪控制器与速度控制器的两层架构,并引入最小均方(Least Mean Square,LMS)自适应状态估计器提升系统的抗噪性。路径点筛选器提升运算速度并减少筛选过程中的关键信息损失,速度规划器在安全行驶前提下生成最优速度曲线。路径跟踪控制器考虑跟踪偏差软约束,提升跟踪效果。LMS状态估计器基于在线矫正的动力学模型,对横摆角速度与横向速度在线估计。搭建dSPACE-TX2硬件在环仿真环境,在高速公路工况及双移线工况下对比所提出方案与传统运动跟踪控制。半实物仿真结果表明,所提出的运动控制架构提升了抗噪性能与21%的跟踪精度,且满足50 Hz高频控制的要求。
基金National Science&Technology Pillar Program of China in the Twelfth Five-year Plan Period(2014BAD06B03)and by“Project 985”of Jilin University.
文摘The reduction of water resources and soil fertility in Northeast China will have a requirement on higher working efficiency of agricultural soil-engaging components.The adhesion and resistance are main problems for soil-engaging tillage components.However,the soil-burrowing or soil-digging animals give inspirations to resolve those problems.Their fair,claw,toe,textured surface and scales have functions of anti-adhesion or resistance reduction.Those results provide a way to realize the sustainable development of modern agriculture by developing novel biomimetic agricultural machinery systems with independent intellectual property rights to meet conservation tillage requirements in the Northern China region.Biological structures of some soil-burrowing or soil-digging animals,such as beetle,mole cricket,earthworm,mole,vole,pangolin,and snake,as well as their mechanisms of anti-adhesion or reducing resistance were reviewed in this paper.Bioinspired applications in Northeast China were also presented in the paper,including moldboard,subsoiler components,furrow opener,roller,and biomimetic rototilling-stubble-breaking blade.In addition,the existed problems in agricultural engineering and the future development trends were discussed.
基金supported by the Development Foundation of Science and Technology in Jilin Province of China (Grant No 20100711)the National 985 Project in Jilin University of China and the Graduate Innovation Foundation of National 985 Project in Jilin University of China (Grant No 20080105)
文摘A three-dimensional motion force tester for animal was used to measure the reaction forces of the feet of a Chinese toad (B. gargarizans) against a horizontal solid surface on which it crawled. The motion behavior of the Chinese toad was recorded by a high-speed camera on line. The motor function of every foot was analyzed. It was found that the lateral force represents the control ability of side-to-side locomotion, controls the lateral movement, and maintains a stable state for the sustainable creeping gesture. The forefeet play the assistant role and the hind feet play the main role in driving. The normal force of the forefeet is significantly greater than that of the hind feet, so the forefeet play the main role in supporting the body and the hind feet play the assistant role. The normal force is significantly greater than the lateral force and the driving force as well. There is little change for the friction force and the support angle of the all four feet. The average value of the support angle is 70°–80°. The Chinese toad’s vola friction coefficient of the forefeet is less than that of the hind feet. The above results indicate that the difference in kinematics and the material characteristic of the contact skin of the Chinese toad. The results could be useful to the structure design and gait optimization of some robots.
基金The project was supported by National Science Fund for Distinguished Young Scholars of China(Grant No.50025516)National Natural Science Foundation of China(Grant No.50675087,50673037,5030600131)+1 种基金“985 Project”of Jilin University,Natural Science Foundation of Henan Educational Committee(Grant No.2009B210006)Science Foundation(2008QN004)and Scientific Research Foundation for Ph.Doctor,Henan University of Science and Technology.
文摘In this study,maize stalk tegument separated from the maize pith was crushed to obtain the fiber.The cross-linking maize starch adhesives considering four main factors(water content,gelatinization temperature,NaOH as gelatinization agent and Na2B4O7·10H2O as cross-linking agent)with three levels were prepared based on an orthogonal test scheme L9(34)in order to increase the water-resisting property and the bonding strength of the common maize starch adhesives.The bonding properties of maize starch adhesives were characterized using shearing strength under compression loading.Physical models of fiber reinforced composites were established according to the microstructure analysis of the four species of insects’elytra including Protaetia orentalis,Copris ochus Motschulsky,Anoplophora chinensis and Cytister bengalensis Aube,which will provide the biomimetic models for the biomimetic laminated boards.The maize stalk fiber biomimetic laminated boards were prepared based on the structural models of the elytra material.The flexural strength and flexural elastic modulus of the biomimetic boards were examined.The results showed that the flexural strengths of the single layer jute fiber,-reinforced maize stalk fiber boards and the dual layer jute fiber reinforced maize stalk fiber boards are higher than those of the common maize stalk fiber boards and the other three groups of jute fiber hybrid reinforced stalk fiber boards because of the biomimetic laminated design.
