Hybrid powertrain is used to provide electric traction to the vehicle and to charge the included battery. Then methods for identifying hazardous situations that could result from malfunctioning behavior at the vehicle level is presented. In meeting this purpose, it covers general topics for the adaptation of motorcycles, safety culture, confirmation measures, hazard analysis and risk assessment, vehicle integration and testing, and safety validation. Multiple-point faults require fault injection testing to verify that safety critical mechanisms remain in a safe state. All components and vehicles undergo numerous accelerated lifetime and durability testing. The inclusion of environmental factors, such as temperature and humidity, during immunity testing is non-trivial. First item definition for hybrid powertrain is detailed out.
Additionally, a crucial part of the innovations focuses on active and passive safety. Low-temperature conditions provide a useful example. Severity S : Defines the seriousness or intensity of the damage or consequences to the life of people passengers and road users and property due to safety goal infringement. Where each of the these three parameters have the following bands. Risk Assessment: Exposure To define exposure you need to estimate the likelihood of the danger. The overall powertrain scheme is being discussed from functional safety perspective.
When temperatures get too high, the powertrain will be reduced to zero torque. The advantage of fault injection testing is that it isolates a potential immunity threat and verifies that the component allows for operation to a safe state if a failure occurs. Currently, immunity testing of vehicle durability is not commonplace across the industry. The terms single point faults metric and latent faults metric are used instead. Notwithstanding, it is important to note that, by standard automotive testing, automotive components endure extreme environmental conditions and must functionally operate across the complete environmental testing spectrum.
What is more, it details how to assign an acceptable risk level to a system or component and document the overall testing process. The proposed method is helpful in extrapolating the knowledge of corrosion management to different field environments where corrosion data are not available. The response surface method and the artificial neural network methodology are employed to obtain the accurate estimation of and in different locations using environmental variables. However, environmental effects cannot be ignored when evaluating electric powertrains during a field immunity event. It takes a resistor, inside of a component that is part of a system installed on a vehicle, that can cause a concern of severity.
That is, each hazardous event is assessed in terms of severity of possible injuries within the context of the relative amount of time a vehicle is exposed to the possibility of the hazard happening as well as the relative likelihood that a typical driver can act to prevent the injury. Various levels of exposure such as E1: very low probability, E2: low probability, E3: medium probability, E4: high probability are assigned to the automotive component being evaluated. The second module was from a vehicle over three years old with over 35,000 miles. Major components of hybrid powertrain are Generator, Traction motor, High voltage battery, Inverters and other auxiliary units. Within the hazard analysis and risk assessment process of this standard, the likelihood of an injurious hazard is further classified according to a combination of exposure E the relative expected frequency of the operational conditions in which the injury can possibly happen and control C the relative likelihood that the driver can act to prevent the injury. Functional Safety rather than Fault Tolerance is the objective of the standard.
Even very efficient electrical powertrains incur thousands of watts of losses, which are manifested as heat within the electronic components. Each hazardous event is classified according to the severity S of injuries it can be expected to cause: Severity Classifications S : S0 No Injuries S1 Light to moderate injuries S2 Severe to life-threatening survival probable injuries S3 Life-threatening survival uncertain to fatal injuries recognizes that consideration of the severity of a possible injury is modified by how likely the injury is to happen; that is, for a given hazard, a hazardous event is considered a lower risk if it is less likely to happen. The discussion within the paper is aimed specifically at electrical components involved with an electric powertrain. The objective of this paper is to discuss test results and models that relate small-scale fire test data to large-scale fire test performance. Hence, having a clear understanding of how the vehicle and the associated sub-systems work, is very important for the. The introduction of highly integrated features brings new challenges that require innovative adaptations of existing safety methodologies and perhaps even some completely new concepts.
It heavily relies on developing testing parameters based on knowledge and experience with the particular product within its most probable environments. Item definition includes system description, its function, boundary, interfaces to external systems. Additional orientations or test cases may be required based on the safety analysis. Regardless, the fault injection test addresses the failure mode and verifies the proper reaction. As a case study, two air bag control modules from field vehicles were testing against the full immunity requirements after being subjected to major water intrusion and corrosion. The idea is you identify the dangers and then design ways to mitigate against them. Error Discrepancy between a computed, observed or measured value or condition, and the true, specified or theoretically correct value or condition.
Based on these deductions, safety goals are formulated. Case Study: Ageing Effects Electrical components typically degrade in performance over time and after considerable usage. Other aspects of the powertrain need to also be considered, such as the type of electric motor. The potential hazards are identified and categorized based on estimating three factors: Severity S of the potential harm of the hazardous event, Exposure E of the operational situation of the hazardous event, and Controllability C of the hazardous event. Let us take the example of charging of a vehicle battery to understand this statement. Electric powertrains introduce new components to the traditional vehicle.
Around these faults, we need to identify measures to prevent the fault from manifesting into a failure which could cause harm to humans. For ; a functional safety consultant identifies and assesses hazards safety risks. The standard also points to some potential shifts in validation processes, such as additional environmental testing if required as an outcome of the safety analysis. A warning lamp already indicates to the operator that the continuation of driving must be taken with caution. One question that first needs to be asked and understood is whether the signal, component, etc.
The coolant temperature increased at a rate of 4. It suppresses intentional steering manouvers. These goals go on to formulate the functional safety requirements, needed to avoid any unreasonable risk for each of the hazardous events. Once, the item definition is identified, the safety-lifecycle kick-starts. It was developed by Averil Coxhead at the School of Linguistics, Victoria University of Wellington, New Zealand. The component itself is tested rigorously for functionality under extreme operating and environmental conditions. It resides along the Arctic Circle and has a yearly average temperature of approximately 0 degrees Celsius.