Blanco, J. and Munoz, L., "Target Cascading Optimization of the Kinematics of a Steering System Coupled to a Double Wishbone Suspension System of a Hybrid Off-Road Vehicle," SAE Technical Paper 2013-01-0967, 2013, doi:10.4271/2013-01-0967.
Target cascading methodology is applied to the optimization problem of the kinematics of a rack and pinion steering mechanism coupled to a double-wishbone suspension system of a hybrid off-road vehicle. This permits the partition of a complex problem into reduced order sub-problems in a hierarchical manner, leading to a more efficient design and optimization process.According to the nature of the problem, it is proposed a four level hierarchy organization. The uppermost level is the general vehicle design problem. The second level consists in various system-level design problems such as frame, powertrain and the set suspension-steering. The steering system design problem is proposed in a third hierarchical level. At the lowest level are the components design problems.The vehicle under study will work mainly under off-road condition at low speed. Hence, at the steering design problem, two main objectives are searched for optimization: steering performance according to the Ackerman criterion and the steering-suspension coupling effect. Given that these two problems are weakly coupled, it is proposed that each objective is treated as an independent geometric optimization problem, and a coordination strategy is applied in order to guarantee a final consistence of the steering general coupled problem.The proposed methodology is applied to a design scenario and an optimal design solution is found. By this methodology, a complex kinematic problem is decomposed into simpler reduced order sub-problems. This decomposition leads to a more straightforward decision making and optimization in the design process.