Electronic structural improvement and experimental verification of a tractor-semitrailer air brake system

Abstract

Brake time delay, which is a major shortcoming of air brake systems, may lead to precarious situations. In this study, the structure of an air brake system of a tractor–semitrailer was optimized by adding a shuttle valve and a two-position-three-port electromagnetic valve between the control pipeline and the charging pipeline downstream of the trailer control valve. The new electronically controlled structure clearly ensures that the semitrailer brakes faster, as validated by a simulation, bench test, and real-vehicle test. The simulation results reveal considerable improvements in the braking time, braking distance, longitudinal kinetic energy, lateral kinetic energy, and β phase plane. The bench test indicates that in the proposed structure, the average response time of service brake cylinders of the first and third axles of the semitrailer are 0.12 and 0.17 s, respectively. In addition, the real-vehicle test indicated that the service brake cylinders of the first and third axles responded 0.12 and 0.18 s earlier than those in the original system, respectively.

Simulation Evaluation of the Influence of Selected Geometric Parameters on the Operation of the Pneumatic Braking System of a Trailer with a Differential Valve

“…(𝜇𝐴) 𝑣6 = (𝜇𝐴) 𝑣6max and 𝑝 = 𝑝 𝑐26 , (12) where 𝐹 𝑐ℎ.𝐴 is the cross-sectional area of piston from chamber A; 𝐹 𝑐ℎ.𝐴 is the cross-sectional area of the piston from chamber ch.B; 𝜂 =0.95 is the coefficient of friction forces in the differential valve; 𝐹 𝑠 is the force from spring; and 𝑝 is the input pressure in valve 6.…”

“…The differential control systems operate in two ranges: in transient states, which occur in real control systems, they include an accelerating action, whereas in steady states, in which there are no changes in the output signal, the differential member maintains a tracking action [10]. There are also concepts of combination valves [11], purely pneumatic or electropneumatic [12].…”

“…Braking time delay is indicated as the main drawback of air braking systems, leading to dangerous driving situations resulting from insufficient system performance. In a previous study [12], the structure of a semitrailer tractor air brake system was optimised by adding a shuttle valve and a two-position, three-port solenoid valve between the control pipe and the charging pipe downstream of the semitrailer control valve. The simulation results showed significant improvements in braking time, stopping distance, longitudinal kinetic energy, transverse kinetic energy and phase plane.…”

Electronic mechanical braking system executive mechanism design, calculation, and modeling based on dynamic control

“…In this trend, the braking system of automobiles needs to meet the requirements of energy recovery and active braking for the safety and energy-saving of electric vehicles. However, although the commonly used hydraulic braking system has a relatively sensitive response and good follow-up, it is laborious to operate, provides limited braking torque, and does not satisfy the new requirements (Huang et al, 2019;Jing and He, 2019). In addition, the traditional hydraulic brake control method has not been able to eliminate the vibration phenomenon that often occurs in the vehicle under braking conditions, which has an adverse effect on the control accuracy of the system.…”