Aim to balance the ride comfort and handling stability of vehicles and improve suspension performance, this paper presents a novel lateral interconnected hydro-pneumatic “inerter-spring-damper” (ISD) suspension integrating a hydro-pneumatic suspension and a fluid inerter, which realizes the lateral connection of the suspension through the inerter. The equivalent mathematical model of the lateral interconnected ISD suspension is established; the 15-degree-of-freedom (DOF) model of the vehicle is built in AMESim, and the key parameters are optimized by genetic algorithm. The response characteristics of the novel hydro-pneumatic ISD suspension and traditional hydro-pneumatic suspension under pulse and random input are comparatively analyzed. The lateral interconnected hydro-pneumatic ISD suspension prototype is developed and tested on the bench. The simulation and test results prove that the proposed new suspension structure has a more effective shock absorption performance than the traditional hydro-pneumatic suspension. Overall, the novel hydro-pneumatic ISD suspension better consider to the ride comfort and handling stability, and the structure is simple, compact, and easy to deploy on practical vehicles.

To realize the control of the inerter and establish a more realistic model of the controllable inerter, this paper designs a controllable inerter and analyzes its nonlinear factors. The ideal model, conventional nonlinear model, and calibrated nonlinear model of the controllable inerter are analyzed and the compressibility of fluid is studied. The prototype of a controllable inerter is tested on the bench and the friction force is identified. The bulk modulus of the fluid in controllable inerter in the fluid-air mixture condition and the pure fluid condition are analyzed. A suspension kinetics model with nonlinear controllable inerter is established. And the performances of the suspension with different nonlinear models are analyzed. The result shows that the inerter force can be reflected through the calibrated nonlinear model. The mixed air has a serious negative effect on the suspension performance and the nonlinear factors will take a negative effect on the control results.

Aiming to improve the road friendliness so as to reduce the road damage caused by heavy multi-axle vehicles, and to enhance the ride comfort, we propose a kind of hydro-pneumatic ISD suspension structure, which is equivalent to a two-stage ISD structure integrating a traditional hydro-pneumatic suspension and a fluid inerter. Firstly, based on the 1/4 model, a genetic algorithm is used to optimize the key structural parameters of hydro-pneumatic ISD suspension. Secondly, the AMESim dynamic model of heavy multi-axle vehicles is built for the performance comparison between the traditional hydraulic and hydro-pneumatic ISD suspensions. Finally, this paper machines a hydro-pneumatic ISD suspension to replace the traditional hydraulic one in a heavy multi-axle vehicle to carry out a road test. Test results indicate that the proposed suspension can effectively restrain the vibrations of sprung and unsprung mass and improve ride comfort as well as road friendliness. The hydro-pneumatic ISD suspension can be applied to engineering.