scholarly journals Study on the Structural Configurations and Pressure Regulation Characteristics of the Automatic Pressure Regulating Valve in the Electronically Controlled Pneumatic Brake System of Commercial Vehicles

2021 ◽  
Vol 11 (22) ◽  
pp. 10603
Author(s):  
Hanwei Bao ◽  
Zaiyu Wang ◽  
Xiaoxu Wei ◽  
Gangyan Li
Keyword(s):  
Simulation Model ◽  
Brake System ◽  
Driving Safety ◽  
Pressure Regulation ◽  
Commercial Vehicles ◽  
Automated Driving ◽  
Automatic Pressure ◽  
Working Principle ◽  
Structural Configurations

Based on the classification of automated driving by the SAE (Society of Automotive Engineers) and the working principle of the ECPBS (Electronically Controlled Pneumatic Brake system), the requirements and the control modes of the APRV (Automatic Pressure Regulating Valve) were concluded. Four structural configurations for APRV were proposed to meet the requirements of the ECPBS. To study the pressure regulating characteristics of the APRV of different structure configurations, a simulation model was established, and a test bench was built. Through experiments, the correctness and the reliability of the simulation model were verified. The pressure regulation characteristics of the APRV of different structure configurations under different control conditions were revealed, and the suitable levels in the SAE automated driving classifications for automatic pressure regulators of different structure configurations were determined; thus, the theoretical underpinning to improve driving safety and develop automated driving was provided.

scholarly journals Pneumatic ABS Modeling and Failure Mode Analysis of Electromagnetic and Control Valves for Commercial Vehicles

Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 318 ◽  
Author(s):  
Xiaohan Li ◽  
Leilei Zhao ◽  
Changcheng Zhou ◽  
Xue Li ◽  
Hongyan Li
Keyword(s):  
Simulation Model ◽  
Failure Modes ◽  
Great Influence ◽  
Solenoid Valve ◽  
Driving Safety ◽  
Mode Analysis ◽  
Commercial Vehicles ◽  
Pressure Regulator ◽  
Braking Performance ◽  
Braking Distance

A failure of the pneumatic ABS (anti-lock braking system) weakens the braking performance of commercial vehicles. It affects the driving safety of vehicles. There are four typical failure modes that include: the failure of the pilot inlet solenoid valve and pilot exhaust solenoid valve of the pressure regulator, the failure of the series dual-chamber brake valve, and the failure of the relay valve. In order to study the braking performance and the rule of vehicles under the failure modes of the pneumatic ABS, the co-simulation model of the pneumatic ABS of the commercial vehicle was established based on AMESim and Simulink softwares. The gas path subsystem of the pneumatic ABS and the vehicle model were built based on AMESim. The controller was established based on Simulink/Stateflow. The data were transmitted between the AMESim and Simulink software by using the data interface block. The co-simulation model was validated by tests. The results showed that the maximum error of the braking deceleration is 13.51%. The model can simulate the braking process of the vehicle well. Based on this, the four typical failure modes of the pneumatic ABS were simulated, and the influences of different failure modes on the braking ability were analyzed. The influence of failure ratio on braking distance in four modes was obtained. It can be seen from the simulation results that the failure of the pilot inlet solenoid valve and the pilot exhaust solenoid valve of the pressure regulator cause the wheel lock. The failure of the lower chamber of the brake valve and the failure of the relay valve have a great influence on the braking distance.

scholarly journals Study on Pressure Change Rate of the Automatic Pressure Regulating Valve in the Electronic-Controlled Pneumatic Braking System of Commercial Vehicle

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 938
Author(s):  
Hanwei Bao ◽  
Zaiyu Wang ◽  
Zihao Liu ◽  
Gangyan Li
Keyword(s):  
Control Method ◽  
Pressure Change ◽  
Autonomous Driving ◽  
Commercial Vehicles ◽  
Change Rate ◽  
Braking System ◽  
Theoretical Support ◽  
Automatic Pressure ◽  
Braking Process ◽  
Vehicle Dynamic Model

In contrast to the traditional pneumatic braking system, the electronic-controlled pneumatic braking system of commercial vehicles is a new system and can remedy the defects of the conventional braking system, such as long response time and low control accuracy. Additionally, it can adapt to the needs and development of autonomous driving. As the key pressure regulating component in electronic-controlled pneumatic braking system of commercial vehicles, automatic pressure regulating valves can quickly and accurately control the braking pressure in real time through an electronic control method. By aiming at improving driving comfort on the premise of ensuring braking security, this paper took the automatic pressure regulating valve as the research object and studied the pressure change rate during the braking process. First, the characteristics of the automatic pressure regulating valve and the concept of the pressure change rate were elaborated. Then, with the volume change of automatic pressure regulating valve in consideration, the mathematical model based on gas dynamics and the association model between pressure change rate and vehicle dynamic model was established in MATLAB/Simulink and analyzed. Next, through the experimental test of a sample product, the mathematical models have been verified. Finally, the key structure parameters affecting the pressure change rate of the automatic pressure regulating valve and the influence law have been identified; therefore, appropriate design advice and theoretical support have been provided to improve driving comfort.

Modelling an electropneumatic brake system for commercial vehicles

2011 ◽  
Vol 1 (1) ◽  
pp. 41-48 ◽  
Author(s):  
P. Karthikeyan ◽  
Ch. Siva Chaitanya ◽  
S.C. Subramanian ◽  
N. Jagga Raju
Keyword(s):  
Brake System ◽  
Commercial Vehicles

scholarly journals Applying Heuristics to Generate Test Cases for Automated Driving Safety Evaluation

2021 ◽  
Vol 11 (21) ◽  
pp. 10166
Author(s):  
Leonard Stepien ◽  
Silvia Thal ◽  
Roman Henze ◽  
Hiroki Nakamura ◽  
Jacobo Antona-Makoshi ◽  
...  
Keyword(s):  
Safety Evaluation ◽  
Driving Safety ◽  
Test Case ◽  
Test Cases ◽  
Generation Process ◽  
Complex Environments ◽  
Automated Driving ◽  
Evaluation Approach ◽  
Naturalistic Driving ◽  
Real Traffic

Comprehensive safety evaluation methodologies for automated driving systems that account for the large complexity real traffic are currently being developed. This work adopts a scenario-based safety evaluation approach and aims at investigating an advanced methodology to generate test cases by applying heuristics to naturalistic driving data. The targeted requirements of the generated test cases are severity, exposure, and realism. The methodology starts with the extraction of scenarios from the data and their split in two subsets—containing the relatively more critical scenarios and, respectively, the normal driving scenarios. Each subset is analysed separately, in regard to the parameter value distributions and occurrence of dependencies. Subsequently, a heuristic search-based approach is applied to generate test cases. The resulting test cases clearly discriminate between safety critical and normal driving scenarios, with the latter covering a wider spectrum than the former. The verification of the generated test cases proves that the proposed methodology properly accounts for both severity and exposure in the test case generation process. Overall, the current study contributes to fill a gap concerning the specific applicable methodologies capable of accounting for both severity and exposure and calls for further research to prove its applicability in more complex environments and scenarios.

scholarly journals Study on the Shifting Quality of the CVT Tractor under Hydraulic System Failure

2020 ◽  
Vol 10 (2) ◽  
pp. 681 ◽  
Author(s):  
Guangming Wang ◽  
Yue Song ◽  
Jiabo Wang ◽  
Wanqiang Chen ◽  
Yunlian Cao ◽  
...  
Keyword(s):  
Simulation Model ◽  
Hydraulic System ◽  
Driving Safety ◽  
Transmission Model ◽  
Seal Ring ◽  
Working Pressure ◽  
System Failures ◽  
Rotary Joint ◽  
Fault Mode

The failure of a hydraulic system will affect the shifting quality and driving safety of a CVT tractor. In order to reveal the response of the tractor under different hydraulic system failures without destroying the transmission, the following methods are proposed in this paper: firstly, building the simulation model of CVT; secondly, building a test bench to test and verify the transmission model to ensure that the simulation model can accurately predict the response of CVT under different clutch oil pressures; thirdly, obtaining the fault oil pressure data without starting the engine and taking the data of fault oil pressure as the input variable of the simulation model; finally, obtaining the response of the CVT tractor under different hydraulic system failures by simulation. It is found that the damage of the seal ring inside the rotary joint has little effect on shifting quality; oil way block can lead to greater shift impact; when seal ring damage and oil way block occur together, the clutch cannot reach the minimum working pressure; clutch piston jamming and oil leak can cause power interruption of the tractor. The results show that it is feasible to study the response of CVT in fault mode by simulation.

scholarly journals An adaptive model predictive approach for automated vehicle control in fallback procedure based on virtual vehicle scheme

2019 ◽  
Vol 2 (2) ◽  
pp. 67-77
Author(s):  
Wei Xue ◽  
Rencheng Zheng ◽  
Bo Yang ◽  
Zheng Wang ◽  
Tsutomu Kaizuka ◽  
...  
Keyword(s):  
Path Planning ◽  
Human Error ◽  
Driving Safety ◽  
Planning Problem ◽  
Adaptive Model ◽  
Sensor Failure ◽  
Automated Driving ◽  
Content Type ◽  
Automated Vehicle ◽  
Virtual Vehicle

Purpose Automated driving systems (ADSs) are being developed to avoid human error and improve driving safety. However, limited focus has been given to the fallback behavior of automated vehicles, which act as a fail-safe mechanism to deal with safety issues resulting from sensor failure. Therefore, this study aims to establish a fallback control approach aimed at driving an automated vehicle to a safe parking lane under perceptive sensor malfunction. Design/methodology/approach Owing to an undetected area resulting from a front sensor malfunction, the proposed ADS first creates virtual vehicles to replace existing vehicles in the undetected area. Afterward, the virtual vehicles are assumed to perform the most hazardous driving behavior toward the host vehicle; an adaptive model predictive control algorithm is then presented to optimize the control task during the fallback procedure, avoiding potential collisions with surrounding vehicles. This fallback approach was tested in typical cases related to car-following and lane changes. Findings It is confirmed that the host vehicle avoid collision with the surrounding vehicles during the fallback procedure, revealing that the proposed method is effective for the test scenarios. Originality/value This study presents a model for the path-planning problem regarding an automated vehicle under perceptive sensor failure, and it proposes an original path-planning approach based on virtual vehicle scheme to improve the safety of an automated vehicle during a fallback procedure. This proposal gives a different view on the fallback safety problem from the normal strategy, in which the mode is switched to manual if a driver is available or the vehicle is instantly stopped.

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