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In this paper, a longitudinal-vertical coupling tracked vehicle dynamic model is established to simultaneously describe the longitudinal, vertical and pitch dynamic responses of the tracked vehicle under off-road conditions. The road wheels are subjected to variable longitudinal-vertical forces due to the terrain unevenness and the excitations are transmitted to the vehicle body through the torsion suspension system. An experiment by means of a scaled-down tracked vehicle was carried out. The comparisons between the field test results and simulation results verified the effectiveness of the coupling dynamic model on predicting the vehicle dynamics. Taking advantage of the coupling tracked vehicle dynamic model, the energy computation formulas are further derived to quantitatively study the vehicle energy consumptions. The energy consumption distributions of the tracked vehicle on uneven road and paved road at different velocities are analysed. The computation results indicate that the developed energy computation method is reliable on predicting the energy generation and dissipation of the tracked vehicle. It has been found that the proportions of damping dissipation energy and road roughness caused energy consumption to total energy consumption are both higher at a greater speed.

In order to improve the shift quality of automatic transmission with synchroniser, a synchroniser electrohydraulic control system equipped with the proportional pressure reducing valves is proposed. The principle of the control system is introduced in detail. The PID controller is used to realise closed-loop control of shift displacement to achieve the synchronisation. A numerical model and a test apparatus have built up to validated the control performance. The simulated and measured engagement and disengagement of the synchroniser with the proposed control system are investigated in detail. The results indicate that the shift displacement is controllable by changing the cylinder chamber pressure. The back pressure value is useful for a smooth synchroniser operation. It is determined by the sleeve motion and the throttle parameter. The back pressure affects little on the synchronisation stage during the engagement process. The proposed method can be used for the optimising design of the electrohydraulic system for the synchroniser control.

BACKGROUND: The severity and mortality of sepsis is related to excessive inflammation and cytokine storm. Nevertheless, little is known about why sepsis has a significant increase in proinflammatory cytokine production, which leads to more severe inflammatory damage. METHOD: Mesenchymal stem cells have achieved certain results in the treatment of sepsis, but the specific mechanism remains to be further clarified. RESULT: Therefore, this paper will elaborate on the currently recognized mechanism of mesenchymal stem cells in the treatment of sepsis, protein phosphorylation mechanism of sepsis inflammatory response and the possibility that mesenchymal stem cells may block the occurrence and development of sepsis by regulating relevant pathways or protein phosphorylation. CONCLUSION: It provides a novel target for mesenchymal stem cells to prevent intervention or therapeutically block the development of sepsis.

In this paper, a longitudinal-vertical coupling dynamic model of a tracked vehicle under uneven road conditions is established. The torsion suspension forces and torques generated by the torsion bar springs and torsion shock absorbers are considered in the present model. The tracked vehicle’s longitudinal acceleration and velocity change at the same time as the vehicle heaves under the excitation of uneven road terrain. The vehicle’s longitudinal-vertical coupling dynamics are explained elementarily by analysing the longitudinal and vertical dynamics of a road wheel based on the road wheel force model. From the coupling tracked vehicle model, the dynamic responses of the vehicle in the vertical and pitch directions as well as the longitudinal direction are investigated. The vehicle dynamics characteristics are compared with those obtained by Recurdyn simulation. The results indicate that the proposed dynamic model performs well in predicting the dynamic characteristics of the tracked vehicle on uneven roads. By means of the coupling dynamic model, the influences of vehicle speed and road conditions on the vehicle’s longitudinal dynamics are further studied. It has been found that both a higher velocity and a larger roughness coefficient will lead to a negative longitudinal acceleration with larger absolute value.

The currently existing energy management control optimization for hybrid electric vehicle (HEV) mainly focuses on fuel economy. Apart from this, there has been some consideration of the impact of emissions, but almost no attention has been paid to drivability performance. Therefore, from the point of view of multi-objectives optimization, the influences of fuel economy, emission and drivability performance on the energy management are comprehensively considered for a parallel HEV. The energy management control parameters and driveline parameters are selected to be optimized parameters. Then, the NSGA-II (Fast Non-dominated Sorting Genetic Algorithm-II) algorithm is proposed to solve the multi-objectives optimization problem. Furthermore, the multi-objectives optimization method for HEV energy management control is established and comparatively simulated with the parallel electric assist control strategy. The results show that the evaluation index of drivability decreases by 27.12% from the maximum and the average enhancement effect of optimization falls by 20.84%. The evaluation index of fuel economy declines by 22.30% from the maximum and the average index drops by 20.26%. The comprehensive index of emission performance descends by 11.33% from the maximum. The proposed multi-objectives optimization algorithm has good convergence and distribution, and obtains more Pareto optimal solution sets, which can provide more selectivity in building HEV energy management control strategies.

This paper proposes an active suspension with voice coil motor (VCM) actuator. The theoretical model that considers uncertainties of the system is built. Taking the voice coil motor actuator into account, a cascade control scheme is proposed. The upper layer controller uses the active disturbance rejection control (ADRC) to generate expect force. The lower layer controller is a PID controller. It is applied to control VCM to track the expect force. The simulation and experiment results indicate that the performance of the proposed active suspension has significant improvement over passive suspension. But the use of voice coil motor alone as an active suspension actuator, energy consumption is huge.

Proportional pressure throttling control characteristics of the synchronizer engagement process was studied. The model of the synchronizer and its electronically controlled hydraulic actuator was built, and then verified by the simulation and the test bench. The results indicate that the proportional pressure throttling control can control the engagement. The back pressure generated by the hydraulic cylinder return throttle has a certain damping effect on the operation of the piston rod. It can prevent the piston rod from moving too fast and the joining process is smoother.

The heat generation and transfer of a voice coil motor (VCM) used for the electrohydraulic proportional pressure valve are investigated. A thermal-network model is set up to predict the VCM component temperature variations. The thermal error and compensation of the output thrust force have been studied. The temperature and the force are measured. The step responses of the valves driven by the VCM and the proportionalsolenoid are presented. The results indicate that the heat transfer model of the VCM is feasible. The coil temperature rises faster than that of the other parts of the VCM. The inner surface temperature of the wall is mainly determined by the copper coil temperature due to the heat convection. The temperature distribution of the wall outer surface is uniform. The proportional pressure control valve driven by the VCM shows a faster step response than the one driven by a proportional solenoid. The fall time of the VCM driving valve is significantly shortened by about 85%. The frequency response of the proportional pressure control valve driven by the VCM is also better than the one driven by the proportional solenoid. The phase lag is reduced by about 80 % with a 5 Hz input signal.

A hydro-mechanical continuously variable transmission for the all-terrain vehicle is investigated. The transmission is with single planetary and input differential. A variable hydraulic pump and a hydraulic motor are equipped to get a wider speed range. The parameter effects on the speed and the torque are analysed. The system parameter design method is studied. The active disturbance rejection control algorithm with feedforward compensation is adopted to the speed ratio control. A hydro-mechanical continuously variable transmission prototype has been built up. The vehicle dynamic performance and the speed ratio control are investigated by simulation and experiment. The vehicle driving and braking performance are tested and discussed. The results indicate that the vehicle acceleration and deceleration can be controlled by changing the displacement ratio. The active disturbance rejection control with feedforward compensation is effective in the speed ratio control. It reduces the speed ratio error of the continuously variable transmission and has good adaptability. The results can be used to optimize the structure and the control strategy of the hydro-mechanical continuously variable transmission.