Design for Cabin Tilting System Employing Single Torsion Bar Using Taguchi Optimization Method

Designing a cabin tilting system for Light Commercial Vehicles using a single torsion bar becomes challenging considering the operator safety and stringent design weight targets. Performance of a good tilting system entirely depends on cabin mass and location of centre of gravity with respect to (w.r.t) to tilting pivot point. Cabin Mass and COG location are very difficult to estimate while designing a new cabin as it is dependent on the maturation of all other cabin aggregates and also the accessories added by the customer. Incorporation design parameter changes like increasing cab tilting angle and increasing torsion bar length, in the later stages of product development, becomes expensive. The objective of this paper is to come up with an optimum design of a single torsion bar tilting employing “Taguchi optimization” for deciding the optimum levels of control factors, which ensures desired performance (i.e tilting effort vs. Cab tilting angle), irrespective of varying noise conditions like cabin mass and centre of gravity location. Experiments carried using MSC ADAMS and optimum control factors decided. Target torque by torsion bar is decided based on stresses in cabin BIW through simulation on FE model using NASTRAN. Verification of cabin tilting efforts and stresses in cabin body structure is done for baseline cases on a prototype cabin.