Research On Co-simulation And Optimal Design Of Deployable Truss-type Robotic Hand

Manipulators play a very important role and position in human production and life.Because the truss-type deployable manipulator can be folded,it has the advantages of convenient transportation and small space occupation.At the same time,it can be expanded into a large-size posture to achieve a larger operating space and grasp a larger target.Due to the characteristics of the truss structure,the manipulator has greater rigidity and gripping force.This paper verifies the feasibility of a truss-type deployable grasping manipulator for grasping operations through theoretical analysis and co-simulation.Based on the results of co-simulation,the manipulator is optimized to provide a theoretical basis for subsequent prototype production.Through the analysis of the geometric relationship between the components of the truss-type deployable manipulator,the change rules between the components during the motion of the manipulator are obtained.The coordinate transformation method is used to obtain the coordinate system of the truss-type deployable manipulator in the unfolding and grasping phases.The kinematics model of the truss-type deployable manipulator is established.After that,the dynamic simulation software RecurDyn was used to complete the kinematics simulation of the manipulator,which verified the correctness of the kinematic relationship derived from the theory.Based on the recursive Newton-Euler method,the relationship between the driving torque of the truss deployable manipulator and the joint rotation angle,angular velocity and angular acceleration is analyzed,and the dynamic model of the manipulator is established.The dynamics simulation of the manipulator was carried out using RecurDyn,and the actual simulation results of the driving torque were compared with the theoretically derived results to verify the correctness of the dynamic model.Because the truss-type deployable manipulator requires more sensors in the grasping stage,the grasping object is uncertain,the control loop is complex,and it is difficult to conduct physical experiments.This paper uses Matlab and dynamics simulation software RecurDyn to build a joint simulation platform to establish the data transmission between the mechanical system and the control system was carried out,and the joint simulation of the grasping process of the truss-type deployable manipulator was carried out.Among them,a grasping strategy based on particle swarm algorithm is designed,and a grasping performance evaluation index is proposed.The grasping results are analyzed and evaluated based on other indicators,and the feasibility of the grasping operation of the truss-type deployable manipulator is verified.According to the mechanical data of the truss-type deployable manipulator collected in the co-simulation,the static analysis of the components of the modular unit was carried out,and the stress and strain analysis results were obtained.Then the topology optimization of the modular unit was carried out to improve the stress distribution and realize the light weight.For the push rod,which is the main load-bearing member,the parameter optimization of its key dimensions is realized,so that its force is reduced to a certain extent.An attempt was made to apply derivative design to the optimization of the truss-type deployable manipulator.According to the force of the truss-type deployable manipulator,a set of derivative design models that meet the design requirements are obtained through derivative design methods.Through the comparison and analysis of the results,the best solution is finally reached.