8 × 8 Vehicle’s Steering Design Using Simulations and Taguchi Method

Eight-wheel drive vehicles have many areas of use, such as military, logistics, firefighting, and disaster response. One of the key design requirements of an 8 × 8 vehicle is to achieve low turning radius at low speeds, without loss of stability and handling at high speeds. In this study, an 8 m turning radius is taken as a preliminary design objective of a 24-ton vehicle, and best handling performance is achieved for high speeds using simulations and the Taguchi Method. While achieving the 8 m turning radius, calculations are based on Akerman’s principle to calculate the turning angles of each wheel. The bicycle model was derived using motion equations, then implemented in MATLAB/Simulink (version 2023b) model to predict the slip angle for six degrees of sinusoidal steering input and a longitudinal speed of 72 kph. The effects of design parameters such as steering configuration and axle distances on slip and steering angle were investigated by design of experiments. With the help of ANOVA analysis performed using Minitab software (version 19), the relationship and optimized solutions were achieved to satisfy both minimum slip angle and steering stability. Minitab optimizer results conclude that Configuration 3 with L1 = 2.45 m, L2 = L3 = 0.8 m, and L4 = 2.3 m axle distances achieved a mean slip of 2.54 × 10−2 radians delay during the sinusoidal maneuver of 4.19 × 10−3 radians at 20 m/s forward speed. Although the optimum solution is achieved with the third configuration, there is not a common solution to achieve both the lowest slip and the highest stability with the same set of design parameters. Finally, a CAD model of the first two axles is established using the software Solidworks (version 2025). A kinematics model including pitman arm, idle arm, and steering rods is designed and virtually validated using ADAMS/View (version 2025.1) multibody dynamics software.