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• The idea of fast-slow switching for full road conditions is proposed. • The stability of the switching system is analyzed. • The accurate estimation of road profile/level and state variables are realized. The hybrid electromagnetic actuator integrates a magnetorheological damper, and a linear motor can effectively reduce the energy consumption of linear electromagnetic active suspension by switching the control parameters with the same dynamic performances. Thus, the intelligent switching control of hybrid electromagnetic active suspension (HEMAS) is investigated with a fast–slow switching method for full road conditions for the first time, which uses the road level and system state variables as the switching rules. First, the intelligent switching control system architecture of HEMAS is designed, and the switching logic is refined. Then, the modified skyhook control strategy is adopted, and the control parameters (including overfull and transient objective control parameters) are optimized for different driving conditions. Then, the simultaneous estimation method of road profile and system state variables and the identification method of road level are studied. The identification result is used as a prerequisite for intelligent switching of system control parameters. Last, a road adaptive intelligent switching control system is designed, and the stability of the switching system is analyzed. Furthermore, a hardware-in-the-loop bench test is performed. The test results verify the effectiveness of the intelligent switching control system in improving the comprehensive performances (dynamic and energy-saving performances) of HEMAS. [ABSTRACT FROM AUTHOR]

• The sensitivity parameters of energy consumption of HEMAS are analyzed. • The energy-reduction mechanism and method of hybrid system are expounded. • The practical application of energy-reduction method is realized. A hybrid electromagnetic active suspension (HEMAS), which integrates a linear motor and magneto-rheological damper, is considered a potential solution to address the high electrical energy consumption of electromagnetic active suspension. The control objectives of HEMAS for different driving conditions are determined according to the dynamic responses of passive suspension (PS). The sensitivity of dynamic performance and electrical energy consumption of HEMAS to controllable and uncontrollable parameters is analyzed for different control objectives. On this basis, the electrical energy-reduction mechanism and control method are obtained. A new hybrid electromagnetic actuator and its control system are designed. The PS and linear electromagnetic active suspension (LEMAS) are taken as comparison objects. A hardware-in-the-loop comparative test, including dynamic performance and energy-reduction tests, is performed. Test results show that in comparison with PS, the suspension working space and dynamic tire load of HEMAS on Grade B are reduced by 88.1% and 6.6%; the suspension working space and body acceleration on Grade D are reduced by 15.9% and 29.4%; and the body acceleration, dynamic tire load, and suspension working space are reduced by 18.3%, 3.7%, and 43.5% on Grade C, respectively. In comparison with LEMAS, the electrical energy consumption of HEMAS for three different roads is reduced by 45.9%, 44.2%, and 39.9%, which proves the effectiveness of HEMAS in coordinating the system dynamic performance and electrical energy consumption. [ABSTRACT FROM AUTHOR]

• A new hydro-pneumatic inerter-based suspension system is proposed. • A two-stage hierarchical control scheme based on model predictive control of HPISS is carried out. • SAHPISS enhance the dynamic performance and hydraulic control valve life of existing SAHPSS. • Demonstrate the improved performance and control method through simulations and experiments. This study presents the nonlinear modeling and model predictive control of a new semi-active hydro-pneumatic inerter-based suspension system (SAHPISS) for the first time. Unlike the traditional semi-active hydro-pneumatic suspension, a fluid inerter is added to the semi-active hydro-pneumatic suspension and a better damping effect can be achieved by adjusting the opening of the hydraulic control valve. First, an accurate analysis modeling of SAHPISS that considers the fluid hydraulic pressure drop, oil-gas nonlinearity and inerter nonlinearity is carried out. Then, a two-stage hierarchical control scheme based on MPC control strategy is proposed for SAHPISS to reduce calculation times of the system and the use rate of the hydraulic control valve and improve the working life of the hydraulic control valve under the consideration of suspension performance requirements. The results of the numerical simulations and experiments prove that the proposed new structure optimizes the low-frequency effect, has a high-frequency effect of the semi-active hydro-pneumatic suspension and verify the effectiveness of the control method. [ABSTRACT FROM AUTHOR]

• A novel on-line estimation method of road profile is proposed for the semi-active suspension. • The estimator is robust considering the variable system parameters and vehicle velocity. • The effectiveness of this method is validated by two groups of tests. As the main excitation source in the process of vehicle driving, road roughness directly affects the vehicle ride comfort and handling stability. In this paper, an on-line estimation method of road profile based on vehicle dynamic response is proposed, which estimates the road disturbance using the transmission characteristics of the system and realizes the road roughness classification by calculating the road information via Power Spectral Density (PSD) estimation. Since the existing standard calculation method of PSD of road disturbance can only be used to process continuous data, an approximate method suitable for discrete data is proposed. In addition, in order to coordinate the response speed and estimation accuracy of the system, the mechanism of the influence of time-window on the estimation accuracy is studied, and the optimal length of time-window is determined. The estimation accuracy under the condition of sprung mass and damping coefficient variation is also analyzed. Finally, a 1/4 semi-active suspension test bench is conducted, and the results show that the system parameters (sprung mass and damping coefficient) and driving speed have little effect on the accuracy of road estimation. At the same time, the accuracy of on-line estimation method of road profile under five different levels of road is more than 90%, and the overall estimation accuracy rate reaches 98.5%, which verifies the effectiveness of on-line road estimation method. [ABSTRACT FROM AUTHOR]