Topology optimization for structural design of transducers using strain gauges

Force transducers are extensively utilized in engineering fields in the form of load cells, 6-axis force sensors for force sensing in robotic manipulation, and wheel force transducers measuring 6-axis force components used in automotive applications. This paper describes a newly developed topology optimization method for the design of the force transducer structure in cases where strain gauges are used as sensor devices. First, design specifications to obtain sufficient output voltage in a Wheatstone bridge composed of strain gauges and structural stiffness requirements are clarified, and the objective functions that satisfy the required specifications are formulated. A multi-objective optimization problem is also formulated for use in finding an optimal structure that incorporates all the design specifications for multi-axis forces. An optimization algorithm is constructed based on a node-based topology optimization method, namely, the CAMD (Continuous Approximation of Material Distribution) method, and SLP (Sequential Linear Programming). Finally, several examples are presented to confirm the usefulness of our proposed methodology for the design of multi-axis force transducer structures.