Theoretical Research On Cooperative Movement Of Multi-Mecanum Wheels

Mecanum wheel omni-directional mobile system has three degrees of freedom in the plane,which can be vertical,horizontal translation and in situ rotation,and can move in any direction while the body's posture remains constant,therefore it is very suitable for narrow space and the place where motion flexibility is higher required,has a broad application prospect.But in the aerospace equipment,advanced track transportation equipment,and other large size and weight of the transport issues,the carrying capacity and size of the four-Mecanum wheels omni-drirectional platform commonly used in domestic at present,which can not meet the requirements.There are two solutions,one is to research overloading omni-directinal mobile platform by mult-Mecanum wheels synergetic drive control;the other is a combination of multiple small mobile plateform to form a mobile system with omni-directional function.Based on the analysis of omni-directional wheel and omni-directional movement characteristics,referencing the current research status at home and abroad,this paper researches on the kinematics coordination of multi-Mecanum wheels by means of theoretical analysis,kinematics modeling,virtual prototype simulation and physical prototype testing,namely to study the relationship between the motion state of the mobile system and the speed constraints of each wheel.The research work of this paper is mainly from the following aspects:1)The basic structural characteristics of the Mecanum wheel are analyzed,and key structural parameters are extracted to guide the design of the Mecanum wheel;to propose a method of creating an accurate roller solid model independently in software by using SolidWorks Motion analysis,and use the secondary development tools VBA to realize the parametric modeling of the roller.2)The kinematic constraint model of a single Mecanum wheel is established,and the general kinematic model of n Mecanum wheels is further deduced;the typical motion pattern of omni-directional mobile system is analyzed,and the specific parameter setting method is given.3)The mainly wheelset layout structure of single and multiple mobile platforms is summarized;the layout structural characteristics of the three-Mecanum wheel is studied,and to deduce and verify the conclusion that the three roller axes intersect two or three points to make the mobile system move in all directions by using the method of calculating the Jacbian matrix determinant;according to the principle of universality,the kinematics model of four-Mecanum wheels omni-directional mobile platform is established,and its kinematic characteristics are analyzed,which is the basis for the study of multi-mobile platforms joint movement;based on the principle of coordinate transformation,the kinematics model of the whole movement of multi-mobile platforms is established.4)Taking the four-Mecanum wheels omni-directional mobile platform as the research object,the Lagrange dynamic equation with dissipation function is established;mobile platform of virtual prototype is established in the SolidWorks,the dynamic simulation of the typical motion pattern of the single and double mobile platform is carried out by using the RecurDyn software,verifies the correctness of the kinematics modeling,and provides a reference for the motion control of the system and prototype production;combining with the simulation process and actual application,the sources of error are summarized.5)On the basis of theoretical research and simulation analysis,the production of physical prototype is completed;finally,the prototype is tested to verify the characteristics of omni-directional movement.