Abstract
The design methodology and validation of a compliant translational joint–based force/displacement integrated sensor is presented in this article. The stiffness analysis of the large displacement high precision compliant translational joint is developed, in which the screw theory–based symbolic formulation method for structures is employed. By combining the stiffness matrix of the single compliant beams and components in this joint, the entire stiffness matrix is derived. The stiffness matrix is validated by finite element analysis (FEA) method. Finally, the compliant translational joint was fabricated with a three-dimensional printer and equipped with a linear position sensor and microcontroller. The displacement of the translational joint is measured and then the force is calculated using the stiffness matrix. A calibration is conducted so that the sub-Newton precision of the sensor is achieved.
Highlights
In certain special applications such as redundantly actuated parallel manipulators as shown in Figure 1, the displacement/force integrated sensor is of great use for measuring both displacement and force simultaneously, and improving the safety of the mechanism in the presence of internal redundant actuating forces
In order to verify the effectiveness of the stiffness matrix of the complaint translation joint (CTJ) under the assumption of the small deformation and the linear elastic material, the static analysis is made using finite element method with SolidWorks Simulation module
The cause accounting for the relative deviation is that the analytical result is based on the compliant CTJ, which is composed of flexible beams interconnected by some rigid parts, while the entire CTJ in finite element analysis (FEA) model is the identical material with an finite elastic modulus
Summary
In certain special applications such as redundantly actuated parallel manipulators as shown in Figure 1, the displacement/force integrated sensor is of great use for measuring both displacement and force simultaneously, and improving the safety of the mechanism in the presence of internal redundant actuating forces. Two hypotheses on the CTJ component are made firstly to derive the stiffness: (a) six connecting rods are ideally rigid and (b) 24 flexible beams satisfy the linear elastic model and the small deformation conditions in the operation of CTJ. These two identical parts in quadrature of the CTJ work together so that they are of parallel relation concerning stiffness. The relationship between the force screw and the displacement screw generated at the origin of a coordinate system on the rigid body S will be derived (i.e. the stiffness matrix or compliance matrix). By the knowledge of mechanics of materials,[13] one can obtain
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
