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Vehicle longitudinal dynamics system has the characteristics of being strongly non-linear, time-varying, and multiple-perturbed, so, it is difficult to build the mathematical model accurately. The control algorithms, based on accurate mathematical model, can hardly achieve the ideal effect, but control methods, which merely adopt input/output data (I/O) of a system, provides a solution. In this paper, by means of combing model-free adaptive control (MFAC) and sliding-mode control (SMC), the model-free adaptive sliding mode control (MFASMC) method is proposed. By comparison with feedback-feedforward control method, the MFASMC method can better improve the control effect and anti-disturbance performance. Meanwhile, the stability of MFASMC method was proven mathematically. Besides, the parameters of MFASMC method were optimized using genetic algorithm. Results of simulation and HiL test shows that the MFASMC method has fast response, strong robustness and smooth output. It would be better to apply it to the longitudinal dynamics control of intelligent vehicles.

Ammonia's distinctive chemical makeup, coupled with its ability to combust fully without carbon emissions, position it as a promising carbon-free fuel but requires careful management to mitigate NO x emissions. In practice, supplementing ammonia with hydrogen addresses its slow combustion rate and high ignition energy requirements. Meanwhile, the introduction of a bluff body (BB) within the pipe can alter the way of flame propagation. This study examines the combustion dynamics of the premixed ammonia/hydrogen/air flame in a pipe with a variable cross-section. The experimental findings demonstrate that increasing both equivalence ratio (Φ) and hydrogen volume fraction (α H 2 ) significantly alters the flame front velocity (FFV) and maximum overpressure (P max), while also enhancing the symmetry of the flame across variable cross-section. The addition of BB creates a vortex in the flame, the formation of which intensifies the combustion of the flame behind the BB, which can promote the generation of Helmholtz oscillations, elevate the amplitude of the pressure, improve FFV, and shorten the flame propagation time in the pipe. With the increase of Φ and α H 2 , the time is shortened less. When Φ = 0.8, α H 2 = 40%, the flame propagation time was shortened by 709 ms. When Φ = 1.2, α H 2 = 60%, the flame propagation time was shortened by 5.67 ms only. In addition, P max and maximum flame front velocity (FFV max) are more sensitive to α H 2 than Φ. After the addition of BB, the increase amplitude of P max and FFV max is increased. However, when Φ = 1.0 and Φ = 1.2, the amplitude of FFV max increase decreases with the increase of α H 2 . This study can provide some suggestions for the application of NH 3 /H 2 fuels in variable cross-sections as well as under obstacles. • Ammonia-hydrogen premixed flames were studied. • The BB makes the propagation time is shortened by 709 ms at Φ = 0.8, α H 2 = 40%. • The BB promotes the generation of Helmholtz oscillations. • The addition of BB creates a vortex in the flame, the formation of which intensifies the combustion of the flame behind the BB. • The BB makes the propagation time is shortened by only 5.67 ms at Φ = 1.2, α H 2 = 60%. [ABSTRACT FROM AUTHOR]