The multi-robot coordinated lifting system is an unconstrained system with a rigid and flexible coupling.The deformation of the flexible rope causes errors in the movement trajectory of the lifting system.Based on the...The multi-robot coordinated lifting system is an unconstrained system with a rigid and flexible coupling.The deformation of the flexible rope causes errors in the movement trajectory of the lifting system.Based on the kinematic and dynamic analysis of the lifting system,the elastic catenary mod-el considering the elasticity and mass of the flexible rope is established,and the effect of the deform-ation of the flexible rope on the position and posture of the suspended object is analyzed.According to the deformation of flexible rope,a real-time trajectory compensation method is proposed based on the compensation principle of position and posture.Under the lifting task of the low-speed move-ment,this is compared with that of the system which neglects the deformation of the flexible rope.The trajectoy of the lifting system considering the deformation of flexible rope.The results show that the mass and elasticity of the flexible rope can not be neglected.Meanwhile,the proposed trajectory compensation method can improve the movement accuracy of the lifting system,which verifies the ef-fectiveness of this compensation method.The research results provide the basis for trajectory plan-ning and coordinated control of the lifting system。展开更多
In this paper, we deal with how agents reason about knowledgeof others in multiagent system. We first present a knowledge representation frame-work called reasoning about others (RAO) which is designed specifically to...In this paper, we deal with how agents reason about knowledgeof others in multiagent system. We first present a knowledge representation frame-work called reasoning about others (RAO) which is designed specifically to representconcepts and rules used in reasoning about knowledge of others. From a class ofsentences usually taken by people in daily life to reason about others, a rule calledposition exchange principle (PEP) is abstracted. PEP is described as an axiomscheme in RAO and regarded as a basic rule for agents to reason about others, andfurther it has the similar form and role to modus ponens and (K) axiom of knowl-edge logic. The relationship between speech acts and common sense is also discussedwhich is necessary for RAO. Based on ideas from situation calculus, this relationshipis characterized by an axiom schema in RAO. Our theories are also demonstrated byan example.展开更多
Language testing is very important and necessary,and moreover as we all know,nowadays,in English language testing, the muhiple-choice item is most widely used and many users regard the multiple-choice item as the most...Language testing is very important and necessary,and moreover as we all know,nowadays,in English language testing, the muhiple-choice item is most widely used and many users regard the multiple-choice item as the most flexible and probably the most effective of the objective item types.The multiple-choice item has its characteristics,advantages and disadvantages.We should bring out its strengths to make up for its weaknesses and use it appropriately.Although it has its limitations,it is suitable for large-scale tests and tests dealing with wide-range knowledge.We should correctly ap- ply testing principles and methods in order to make testing more effective and reliable.展开更多
基金the National Natural Science Foundation of China(No.51965032)the Natural Science Foundation of Gansu Province of China(No.22JR5RA319)+1 种基金the Science and Technology Foundation of Gansu Province of China(No.21YF5WA060)the Excellent Doctoral Student Foundation of Gansu Province of China(No.23JRRA842).
文摘The multi-robot coordinated lifting system is an unconstrained system with a rigid and flexible coupling.The deformation of the flexible rope causes errors in the movement trajectory of the lifting system.Based on the kinematic and dynamic analysis of the lifting system,the elastic catenary mod-el considering the elasticity and mass of the flexible rope is established,and the effect of the deform-ation of the flexible rope on the position and posture of the suspended object is analyzed.According to the deformation of flexible rope,a real-time trajectory compensation method is proposed based on the compensation principle of position and posture.Under the lifting task of the low-speed move-ment,this is compared with that of the system which neglects the deformation of the flexible rope.The trajectoy of the lifting system considering the deformation of flexible rope.The results show that the mass and elasticity of the flexible rope can not be neglected.Meanwhile,the proposed trajectory compensation method can improve the movement accuracy of the lifting system,which verifies the ef-fectiveness of this compensation method.The research results provide the basis for trajectory plan-ning and coordinated control of the lifting system。
文摘In this paper, we deal with how agents reason about knowledgeof others in multiagent system. We first present a knowledge representation frame-work called reasoning about others (RAO) which is designed specifically to representconcepts and rules used in reasoning about knowledge of others. From a class ofsentences usually taken by people in daily life to reason about others, a rule calledposition exchange principle (PEP) is abstracted. PEP is described as an axiomscheme in RAO and regarded as a basic rule for agents to reason about others, andfurther it has the similar form and role to modus ponens and (K) axiom of knowl-edge logic. The relationship between speech acts and common sense is also discussedwhich is necessary for RAO. Based on ideas from situation calculus, this relationshipis characterized by an axiom schema in RAO. Our theories are also demonstrated byan example.
文摘Language testing is very important and necessary,and moreover as we all know,nowadays,in English language testing, the muhiple-choice item is most widely used and many users regard the multiple-choice item as the most flexible and probably the most effective of the objective item types.The multiple-choice item has its characteristics,advantages and disadvantages.We should bring out its strengths to make up for its weaknesses and use it appropriately.Although it has its limitations,it is suitable for large-scale tests and tests dealing with wide-range knowledge.We should correctly ap- ply testing principles and methods in order to make testing more effective and reliable.
