基于预期功能安全的矿用运输车辆自动紧急制动系统研究

Automatic emergency braking system of open-pit mine vehicles based on Safety of the Intended Functionality

  • 摘要: 随着智慧矿山建设的推进,为保障运输作业安全,矿用运输车辆上开始部署自动紧急制动系统。然而由于露天矿区常伴随雨、雪等极端天气、粉尘环境以及湿滑坡道路面,导致自动紧急制动系统的制动时间过晚最终发生碰撞或是在安全情况下就实施制动的现象时有发生。本文针对矿用运输车辆在露天矿山作业过程中自动紧急制动系统预期功能安全问题开展研究,以解决由于风险场景触发而导致系统功能不足,进而引发系统失效的安全问题。首先,本文运用系统过程理论方法厘清自动紧急制动系统出现不安全行为的致因场景,提出感知和决策系统的改进策略。其次,采用基于暗通道的图像增强方法和扩展卡尔曼滤波融合算法来解决在恶劣天气下感知不准确的问题;提出考虑坡度、附着系数、滑移率、车辆载重等因素的碰撞时间模型,以提升决策系统对矿山作业环境的适应性。最后,基于MATLAB/Simulink、TruckSim、PreScan建立联合仿真平台,并筛选出危险度最高的测试用例开展测试。结果表明,在非路口场景测试中,仅改进感知的系统发生了碰撞,在路口场景测试中,其安全裕度也较低。而仅改进决策的系统由于天气、光照等环境因素的影响,导致感知到的数据不够准确从而决策过于保守而提前制动。感知和决策综合改进的系统可以有效的避免碰撞,且不会过早的触发制动。本文对于自动紧急制动系统中感知和决策的综合改进能够有效避免过早和过晚制动的问题,提高了系统的安全性和适应性。

     

    Abstract: With the development of intelligent mining, autonomous emergency braking system is equipped on the mining transportation vehicles. However, since open-pit mining areas are often accompanied by unstructured roads and extreme weather such as rain, snow and fog, as well as poor road adhesion coefficient under the influence of weather, these have a great impact on the perception and decision-making system of autonomous emergency braking system, which often leads to collision or braking under safe conditions. This paper conducts investigation on the intended functional safety issues of the autonomous emergency braking system for mining transport vehicles during open-pit mining operations, aiming to address the safety issues caused by system failures due to insufficient system functionality triggered by risk scenarios. Firstly, this paper employs the systematic theory process to identify the scenarios that cause unsafe behaviors in the autonomous emergency braking system and proposes improvement strategies for the perception and decision-making systems. Secondly, it adopts an image enhancement method based on dark channel prior and an Extended Kalman Filter fusion algorithm to address the issue of inaccurate perception in adverse weather conditions. A collision time model that considers factors such as slope, coefficient of friction, slip ratio, and vehicle load is proposed to enhance the adaptability of the decision-making system to mining operational environments. Finally, a joint simulation platform is established based on MATLAB/Simulink, TruckSim, and PreScan, and the most hazardous test cases are selected for testing. The results indicate that in non-intersection scenario tests, collisions occurred in systems where only perception was improved, and in?intersection?scenario tests, these systems also exhibited lower safety margins. In contrast, systems where only the decision-making component was improved resulted in inaccurate perception data due to environmental factors such as weather and lighting, leading to overly conservative decisions and premature braking. Systems with comprehensive improvements in both perception and decision-making can effectively avoid collisions without triggering braking too early. This paper demonstrates that comprehensive improvements to both perception and decision-making in automatic emergency braking systems can effectively address the issues of premature and delayed braking, enhancing the system's safety and adaptability.

     

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