Design And Research Of Flexible Parallel 3d Force/Torque Sensor

In this thesis,a three-dimensional force/moment sensor is designed,and research work on the configuration design,stiffness modeling,structural design,optimization and machining,as well as the construction of a calibration bench and experiments of the flexible parallel three-dimensional force/moment sensor is carried out,and the main innovations and research work achieved are as follows:Based on CI-type parallel top wire coupling base body,a 2R1T(two-turn,one-shift motion)multi-layer flexible motion unit general model is established.The flexibility of the basic flexible unit,the stiffness of the kinematic subunit,the flexibility of the tandem branch chain and the flexibility of the multilayer 2R1T general model are established by using the tandem flexibility and parallel stiffness modeling methods of the flexible body.2R1T kinematic units have good flexibility and meet the requirements of most three-degree-of-freedom applications,and the proposed 2R1T flexible kinematic units enrich the number of types of 2R1T configurations and provide a theoretical modeling basis for future 2R1T applications provide a theoretical modeling basis.A flexible parallel three-dimensional force/torque sensor structure is proposed based on the parallel configuration with few degrees of freedom.The sensor structure consists of a fixed platform with a middle column,four identical flexible tandem branched chains and a force measuring platform with a circular elastic spoke plate.Two flexible ball hinges and one S-shaped structural unit are connected in series to form a flexible support chain.The flexibility matrix of the flexible ball hinge is established by using segmental modeling idea and method;the flexibility matrix of the elastic spoke plate is established by using the finite element method;the overall stiffness model of the S-shaped structural unit and the 3D force transducer is established by using the parallel mechanism stiffness modeling method.The 3D force/moment sensor 3D model was established using Solid Works 3D modeling software,and the response surface optimization module and topology optimization module in Workbench software were used to optimize the key dimensional parameters and the overall structural lightweighting of the sensor model.By setting the optimization objectives and constraints,the structural dimensional parameters of the elastic spoke plate of the sensor were optimized by using the central combination design experiment method,and three sets of optimal optimization parameters were obtained;the lightweight design of the sensor was carried out by setting the lightweighting area and target conditions,and the optimal configuration was obtained.The results show that the overall deformation of the optimized sensor is increased by about 20%,the desired strain is increased by about 293%,the sensitivity is significantly increased,and the overall mass is reduced by 9.4%.The S-shaped structural unit was analyzed to define the path strain variation curve,determine the strain gauge placement,and attach the resistive strain gauge full bridge circuit to the flexible beam of the S-shaped structural unit by means of patching to form the measurement module.Select bolts and strength check;draw up engineering drawings of the 3D force sensor prototype and machine the prototype.For the sensor design calibration test bench proposed this time,the aluminum alloy profile is used as the calibration test bench frame,and the pulley-weight structure is selected.Perform multiple calibration experiments on the three-dimensional force/torque sensor in the directions of F_z,M_x and M_y,and record the data.The coupling calibration matrix is analyzed by the least square method,and finally the error analysis is carried out.