Parameters Optimisation of a Hydraulically Interconnected Suspension in a Stretcher Using Genetic Algorithm

Changes in acceleration and manoeuvring during ambulance operations can make the stretcher unstable. Furthermore, the vibration created by uneven roadways can worsen the patient condition, leading to nausea. Therefore, this research attempts to control the ambulance stretcher vertical vibration, roll and pitch acceleration by Pitch Roll Interconnected Hydraulic Suspension (PRIHS) system. To evaluate the effectiveness of a PRIHS system, a 14 Degree of Freedom (DOF) ambulance vehicle with an anti-roll bar and a 3 DOF ambulance stretcher were used. Additionally, a Genetic Algorithm (GA) based optimisation was attempted to find the optimal settings for a PRIHS system. The AMEsim platform was used to build and test an ambulance vehicle model with a stretcher. The model was tested on ISO 8608 D class road roughness to assess the ambulance stretcher pitch resistance, roll resistance, and ride comfort level. From the simulation results, the PRIHS has significantly improved the stretcher ride comfort, roll stability, and pitch stability compared to the standalone system. The GA-optimized PRIHS system enhanced the stretcher's ride comfort, roll stability, and pitch stability by 36.86%, 33.65%, and 10.44%, respectively, compared to the PRIHS.