ISO 26262 Concept Phase Analysis on Distributed Electro-Hydraulic Braking System: The Influence of System Architecture on ASIL Decomposition

Author(s):  
Zhizhong Wang ◽  
Liangyao Yu ◽  
Ning Pan ◽  
Lei Zhang ◽  
Jian Song

The Distributed Electro-hydraulic Braking system (DEHB) is a wet type brake-by-wire system. As a safety critical automotive electrical and/or electronic (E/E) system, DEHB shall be designed under the guideline of ISO 26262 in order to avoid unreasonable risk due to the malfunctions in the item. This paper explores how the Automotive Safety Integrity Level (ASIL) decomposition in the concept phase is influenced by the system architectures of DEHB. Based on a typical hazardous event, analysis on DEHB with the same system architecture as the Electro-mechanical Braking system (EMB) is carried out, which is taken as the basis for comparison. Two types of DEHB with different system architectures are then analyzed. Results show that the adoption of hydraulic backup enables ASIL decomposition in the pedal unit. The adoption of both hydraulic backup and normally open balance valves offers the opportunity to perform ASIL decomposition in the brake actuator system of DEHB.

2015 ◽  
Vol 781 ◽  
pp. 500-503
Author(s):  
Kyung Jung Lee ◽  
Hyun Sik Ahn

In this paper, we propose a hardware-in-the-loop simulation (HILS) for functional safety compliant electric power steering (EPS) system. The proliferation of electric and electronic systems in vehicles has brought the new automotive standard ISO 26262 for the safety of functions. The proposed EPS system should be Automotive Safety Integrity Level (ASIL) D compliant, which is the highest ASIL level. Therefore, EPS system complies with functional safety and HILS is configured to verify performance of functional safety compliant EPS system.


Electronics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 732
Author(s):  
Frederico Ferlini ◽  
Laio Oriel Seman ◽  
Eduardo Augusto Bezerra

Modern vehicles are integrating a growing number of electronics to provide a safer experience for the driver. Therefore, safety is a non-negotiable requirement that must be considered through the vehicle development process. The ISO 26262 standard provides guidance to ensure that such requirements are implemented. Fault injection is highly recommended for the functional verification of safety mechanisms or to evaluate their diagnostic coverage capability. An exhaustive analysis is not required, but evidence of best effort through the diagnostic coverage assessment needs to be provided when performing quantitative evaluation of hardware architectural metrics. These metrics support that the automotive safety integrity level—ranging from A (lowest) to D (strictest) levels—was obeyed. In this context, this paper proposed a verification solution in order to build an approach that can accelerate the diagnostic coverage assessment via fault injection in the semiconductor level (i.e., hardware description language). The proposed solution does not require any modification of the design model to enable acceleration. Small parts of the OpenRISC architecture (namely a carry adder, the Tick Timer peripheral, and the exception block) were used to illustrate the methodology.


Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6942
Author(s):  
David Marcos ◽  
Maitane Garmendia ◽  
Jon Crego ◽  
José Antonio Cortajarena

The increasing use of lithium batteries and the necessary integration of battery management systems (BMS) has led international standards to demand functional safety in electromobility applications, with a special focus on electric vehicles. This work covers the complete design of an enhanced automotive BMS with functional safety from the concept phase to verification activities. Firstly, a detailed analysis of the intrinsic hazards of lithium-based batteries is performed. Secondly, a hazard and risk assessment of an automotive lithium-based battery is carried out to address the specific risks deriving from the automotive application and the safety goals to be fulfilled to keep it under control. Safety goals lead to the technical safety requirements for the next hardware design and prototyping of a BMS Slave. Finally, the failure rate of the BMS Slave is assessed to verify the compliance of the developed enhanced BMS Slave with the functional safety Automotive Safety Integrity Level (ASIL) C. This paper contributes the design methodology of a BMS complying with ISO 26262 functional safety standard requirements for automotive lithium-based batteries.


2014 ◽  
Vol 556-562 ◽  
pp. 1358-1361 ◽  
Author(s):  
Wen Bo Zhu ◽  
Fen Zhu Ji ◽  
Xiao Xu Zhou

Wire of the brake pedal is not directly connected to the hydraulic environment in the braking By-wire system so the driver has no direct pedal feel. Then pedal simulator is an important part in the brake-by-wire system. A pedal force simulator was designed based on the traditional brake pedal curve of pedal force and pedal travel, AMESim and Matlab / Simulink were used as a platform to build simulation models and control algorithms. The simulation results show that the pedal stroke simulator and the control strategy meet the performance requirements of traditional braking system. It can be used in brake by wire system.


Author(s):  
Xiaohui Liu ◽  
Liangyao Yu ◽  
Sheng Zheng ◽  
Jinghu Chang ◽  
Fei Li

The automatic driving technology of vehicle is being carried out in real road environment, however, the application of unmanned vehicle still needs proof and practice. Autonomous vehicles will be in the stage of co-drive for a long time, that is, driver-control and autonomous system assisting or autonomous system control and driver assisting. The braking system of the intelligent vehicle needs to work in driver driving mode or automatic driving mode during a long stage. Brake-by-Wire system is the development trend of vehicle braking system. The brake modes of the Brake-by-Wire system can be switched easily and it can satisfy the demand for braking system of the intelligent vehicle. However, when the driving mode changes, the characteristic of the braking intention and braking demand will change. In order to improve the braking performance of the intelligent vehicle, hydraulic pressure control and parameter optimization of the Brake-by-Wire system during different driving modes should be different. Researches are made on hydraulic pressure control and parameter optimization of the Brake-by-Wire system with consideration on differences of braking intensity input and braking requirement between driver driving mode and automatic driving mode through theory analysis, Matlab/Simulink-AMESim simulation and bench test. The study is helpful for improving the braking performance of Brake-by-Wire system in hydraulic pressure control of driver-automation cooperative driving.


2018 ◽  
Vol 2018 (1) ◽  
pp. 000104-000109
Author(s):  
Mollie Benson ◽  
Burton Carpenter ◽  
Andrew Mawer

Abstract Radar is currently employed in automotive applications to provide the range, angle, and velocity of objects using RF waves (77GHz). This paper outlines solder joint reliability of a specific micro-processor that processes data received from a SRR (short range radar operating from 0.2 to 30 meters). It is a powerful digital signal processing accelerator, which targets safety applications that require a high Automotive Safety Integrity Level (ASIL-B). The paper explores the package design and construction, SMT (surface mount technology) assembly, and board level reliability testing of various BGA pad surface finish and solder ball alloy materials on a 0.65 mm pitch, 10 × 10 mm body 141 MAPBGA (mold array process-ball grid array) package. The package configurations include two BGA pad surface finishes (Ni/Au and OSP [organic solderability protectant]) and three solder alloys (SnAg, SAC405, and SAC-Bi [a Bi containing SAC derivative]). Solder joint reliability analysis was performed through AATS (air-to-air thermal shock) between 40°C and +125°C and JEDEC Drop Testing at 1500G's. Thermal shock was extended until at least 75% of the populations failed, which was well past the points needed to qualify the packages for the intended end-use applications. The evaluations of the micro-processor indicate that the MAPBGA package can meet the ASIL-B specification requirements with optimized combinations of BGA pad surface finish and solder alloy. The focus of this paper was to determine the baseline solder-joint thermal shock and JEDEC drop performance with varied BGA pad surface finish and solder ball alloy materials.


2009 ◽  
Vol 2009 ◽  
pp. 1-10 ◽  
Author(s):  
Thilo Pionteck ◽  
Roman Koch ◽  
Carsten Albrecht ◽  
Erik Maehle

Runtime reconfigurable system-on-chip designs for FPGAs pose manifold demands on the underlying system architecture and design tool capabilities. The system architecture has to support varying communication needs of a changing number of processing units mapped onto diverse locations. Design tools should support an arbitrary placement of processing modules and the adjustment of boundaries of reconfigurable regions to the size of the actually instantiated processing modules. While few works address the design of flexible system architectures, the adjustment of boundaries of reconfigurable regions to the size of the actually instantiated processing modules is hardly ever considered due to design tool limitations. In this paper, a technique for circumventing this restriction is presented. It allows for a rededication of the reconfigurable area to a different number of individually sized reconfigurable regions. This technique is embedded in the design flow of a runtime reconfigurable system architecture for Xilinx Virtex-4 FPGAs. The system architecture will also be presented to provide a realistic application example.


1992 ◽  
Vol 7 (3) ◽  
pp. 215-249 ◽  
Author(s):  
V. Mital

AbstractThe financial domain has seen considerable knowledge Systems activity. Some of the efforts have resulted in deployable Systems, but many others have met with much less success. Commentators have attempted to discern broad, universal indicators which explain or predict success. More recently, however, it has become clearer that a principal cause of the difficultes encountered is the incongruence between the real world task and the System architecture employed by developers. Proceeding from the latter perspective, this paper concerns itself with knowledge Systems for the provision of investment related financial advice. The various tasks involved are differentiated and correlated to the System architectures employed by developers. It is seen that while simple rulebased Systems suffice for some tasks, others indicate the need for techniques such as Case-Based Design.


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