Due to increasing concerns with petroleum usage and the increasing federal fuel economy regulations, electric powertrains have become more accepted by automotive manufacturers and can be found in production and within numerous development programs.
Although electric propulsion vehicles were first built over 100 years ago, such vehicles are not commonplace in today’s automotive market. As with any “new” technology, concerns arise regarding safety and reliability of such vehicles. The functional safety standard ISO 26262, introduced in final draft in 2011, provides crucial safety-related requirements for passenger vehicles including those employing electrical propulsion. Although the standard has already had a large influence on automobile manufacturers and suppliers, it’s implications for EMC have not previously been fully clarified.
The objectives of the paper are firstly to compare and contrast present electromagnetic compatibility (EMC) vehicular and component requirements and processes to those suggested by the recently released functional safety standard, ISO 26262 [1]. Secondly, the paper analyzes other state-of-the-art standards and guidelines for EMC and functional safety that are not directly referenced by ISO 26262. Thirdly, the paper discusses environmental concerns and covers a real case study of a safety critical E/E component after real ageing effects. Finally, the paper provides suggestions on methods to improve EMC processes for electric powertrains to allow for greater acceptance to ISO 26262. The discussion within the paper is aimed specifically at electrical components involved with an electric powertrain.
ISO 26262 Compared to Present Automotive EMC Requirements
ISO 26262 Coverage of EMC
EMC or Electrostatic Discharge (ESD) is referenced in 5 of the 10 total parts of ISO 26262, as illustrated in Table 1. As is seen in Table 1, besides the testing requirements of Part 5, there is a great focus on failures that can be caused by EMC within the analysis and design of the hardware component. In the development of production vehicles, recognizing and correcting issues early in the development are critical for cost effective and reliable products. EMC becomes just one of the numerous considerations that are required in the effective safety analysis required by ISO 26262.
Table 1: References to EMC or ESD in ISO 26262 [1]
Another key feature of ISO 26262 is the hazard analysis and risk assessment described in Part 3. EMC is not explicitly referenced in this section because it is only one of many potential causes to a hazard. These potential causes to a hazard should be identified in a Failure Mode and Effects Analysis (FMEA) and should include EMC effects. Part 3 determines the Automotive Safety Integrity Level (ASIL) for each function, which then sets the minimum requirements to reduce the probability of a failure to cause an unreasonable risk [1]. There are a total of four ASIL, with ASIL D having the most stringent requirements and ASIL A the least stringent. Additionally, there is a quality management (QM) class that signifies that it has no requirement to comply with ISO 26262.
It is not possible to assign an ASIL only to an immunity event; however, there could be a specific hazard identified which only EMC could cause. Unlike the many EMC requirements where limit lines are established with pass/fail criteria, there is no one defined threshold determining if the specific component or system complies with the intent of ISO 26262. A hazard analysis and risk assessment must be conducted for each component on each vehicle to determine the appropriate ASIL level, as shown in Table 2. It is an important task of the safety manager and the responsible EMC team to provide the input of any EMC related cause of hazards to the appropriate group conducting the hazard analysis and risk assessment. This is a brainstorming activity to see if any immunity event could cause a unique hazard not already identified by other potential failure modes. As will be shown later in the paper, nearly all immunity effects are already identified by the most common failure modes of an electronic signal. An example of an exception could be an ESD event. The voltage level and pulse characteristics are very unique to this specific ESD effect and could cause a hazard not previously considered.
Table 2: ASIL determination table from ISO 26262 with ASIL ratings shown in bold for each combination of severity, probability, and controllability [1]
Consider the example of an ESD event causing a unique hazard, such as degradation of a safety critical signal in the vehicle wiring harness during service. If the safety critical signal is from a powertrain E/E component function that has an influence on acceleration, it could have a severity of S3 (life-threatening injury) and a controllability of C3 (difficult to control). However, a hazard caused by an ESD event may only be an E2 (<1% of average operating time) or E1 (occurs less often than once a year for the great majority of drivers). This then establishes the highest possible requirements for that function according to an ASIL B or ASIL A.
ISO 26262 EMC Testing Requirements
Table 3 highlights the required immunity tests as specified by ISO 26262. It is noted that ISO 7637-3 has been added in the final draft, recently published at the time of this paper, in comparison to the 2009 draft of ISO 26262 [1,2]. All ISO tests, numbers 1 through 6, are common tests required currently by OEMs or by an equivalent test. Additionally, the tests called out within the four tables of IEC 61000-6-1 are generally covered under internal OEM requirements and are often exceeded in field strengths and frequency coverage. The fourth table of IEC 61000-6-1 is specific to high voltage (HV) components with an interface to ac power, such as the HV battery charger connection to the power grid. Item number 8, IEC 61508, is the general functional safety requirement for any electronic or electrical system without regards to the specifics of the automotive industry [3]. It does not have any specific requirements for passenger vehicles dealing with EMC; however it does reference IEC 61000-1-2, a general standard on EMC and functional safety [4]. IEC 61000-1-2 will be discussed later in the paper. It is noted that it does not provide additional types of immunity testing, but rather suggests increasing the test severity of some general standards.
Table 3: Immunity tests as required by ISO 26262 [1]
To verify the standard testing requirements from the OEMs, the EMC requirements from Ford Motor Company (Ford), General Motors Company (GM), and Chrysler Group LLC (Chrysler) were reviewed and compared against ISO 26262 requirements [5-7]. Tests numbered 1-6 of Table 3 are all required by the reviewed OEMs with the exception of ISO 7637-3 by Ford. Ford requires some of the transient tests of ISO 7637-3, but also includes several other pulses not captured in the specification based on experience with their vehicle testing. Both tests numbered 7 and 8 of Table 3 are not specific to passenger vehicle requirements. However, specified tests and test levels of IEC 61000-6-1 are already covered under the OEM EMC requirements. For the case of RF immunity, the frequency range is expanded to cover from 1 MHz up to greater than 3 GHz on a component level, rather than the 80 MHz to 2.7 GHz as specified by ISO 61000-6-1. Ford and GM do, however, stop their vehicle testing at 2 GHz. Additionally, the power levels are increased significantly from 3 V/m to standard levels of 70 and 100 V/m with high RF bands tested as high as 600 V/m. The requirement IEC 61508 is in some sense a circular requirement, since ISO 26262 covers the functional safety requirements specific to passenger vehicles whereas IEC 61508 is generic for E/E components in all industries. Notwithstanding, the reviewed OEMs have additional requirements and guidelines for immunity in comparison to the ISO 26262, including, but not limited to: IEC 61000-4-21 (reverberation chamber test methods), ISO 11452-1 (general immunity guidelines), ISO 11452-8 (immunity to magnetic fields), ISO 11452-9 (test methods for electrical disturbances from narrowband radiated EM energy), ISO 7637-1 (definitions from conducted and coupling tests), CISPR 12 and 25, and military standards such as MIL-STD-461E. All mentioned requirements apply to vehicles with an electric powertrain as well, not to mention that many OEMs have additional internal requirements specific to HV components.
As has been shown, OEM EMC requirements meet or exceed the immunity and electrostatic discharge (ESD) testing requirements as specified by ISO 26262 in most cases. In some particular cases there are gaps between the reviewed OEM EMC requirements and ISO 26262 requirements. Each OEM should evaluate their requirements according to ISO 26262 to confirm compliance.
EMC and ESD testing is only one of 10 possible integration tests to verify the robustness of the hardware under external stresses according to the tables with ASIL requirements in Part 5 of the standard [1]. EMC and ESD requirements are highly recommended for all ASIL levels, ASIL A to ASIL D.
ISO 26262 deals with the specifics of the close handling of functional safety critical circuits and safety mechanisms allowing the vehicle to go into a safe state, even under faulted conditions. These failures, and the mechanisms which provide safety during failures, may or may not be related to EMC in a given case. The challenge is to understand the features of ISO 26262, and apply them efficiently to EMC-related processes in the automotive industry.
For example, ISO 26262 mandates that the planning and definition of safety critical activities are handled by the safety manager for both the supplier and OEM portions of the development life cycle. In practice this requires proper coordination between the safety manager and the EMC testing groups. Based on safety and impact analysis, additional orientations or devices under test (DUT) could be requested. Such determination is made on a case-by-case basis. Additionally, the safety manager has the responsibility of communicating to the EMC testing groups on the monitoring and focus of safety critical signals. The safety manager must take an active role in the creation of test plans and must review the results. The safety manager has an overall view of the safety of the particular component and can provide the best direction to ensure the tests are conducted properly, with the guidance from the EMC test group, for the particular component.
Automotive EMC Lessons Learned
One measure, defined in Part 5 of ISO 26262 to prevent common design faults, is the usage of lessons learned. EMC considerations for the automotive industry have been established since the 1980s, when automotive EMC design and test standards were first developed. The automotive EMC community has traditionally played an active role in the development of standards and has followed the recommendations of many international organizations such as International Organization for Standardization (ISO), Comité International Spécial des Perturbations Radioélectriques (CISPR), European Committee for Electrotechnical Standardization (CENLEC), Society of Automotive Engineers (SAE), Automotive EMC Laboratory Recognition Program (AEMCLRP), and International Commission on Non-Ionizing Radiation Protection (ICNIRP). The automotive industry participates annually at ISO and CISPR meetings, sending delegates from each representing country. Internal Original Equipment Manufacturer (OEM) requirements exceed Federal regulations and, in some cases, exceed the testing requirements of the previously mentioned organizations. Additionally, within a number of countries, the OEM EMC community has taken actions together to harmonize with other OEMs and to share the lessons learned from their own experience. This is apparent within the United States by the SAE automotive EMC working committee that is open to both OEMs and suppliers. This knowledge sharing is uncommon in many areas within the development of passenger vehicles due to the competitive nature of the automobile industry.
The lessons learned by the EMC community have grown and extends to knowledge gained over 30 years of experience on mass production vehicles. Electric powertrains introduce new components to the traditional vehicle. However, the handling of failures due to EMC on electric powertrains with respect to functional safety is similar to electronic throttle controls or other drive-by-wire technologies, where the industry has gained valuable insights over time since its inception in the 1980s. Both the controllers for electrical propulsion and electronic throttle control have similar functional safety concerns due to their direct impact on acceleration and braking. A consortium of German OEMs and suppliers established a set of guidelines for functional safety of electric throttle controllers starting in the late 1990s [8]. The contents of these requirements are often tailored to also consider electrical powertrain requirements. In many cases the functional safety relevant items will be the same; such as torque monitoring considerations, loss of CAN strategies, enabling a safe operating state, and reduced torque operating strategies.
In summary, the specific immunity tests required by ISO 26262 are already in practice in industry, with some small exceptions that require further evaluation from the OEM. In part, this reflects the efforts of industry over the past several decades to update and refine their methodologies regarding EMC. It is also a reminder of the nature of ISO 26262, which requires more than a set list of tests, as will be shown in future sections of this paper.
State-of-the-art: Functional Safety for EMC
The requirements for hardware development, according to ISO 26262, are adapted to the state-of-the-art for the automotive industry. This then implies the usage of state-of-the-art standards for EMC with respect to functional safety. However, currently there exists no document specific to the automotive industry. A general industry standard, IEC 61000-1-2, does exist and will be evaluated among other technical papers here with reference to the specifics of automotive and electric powertrains. IEC 61000-1-2 is a supplement to IEC 61508; to provide guidance to achieve adequate immunity to EMC for safety-related systems and equipment.
IEC 61000-1-2 begins the validation requirements stating that there is no practical means to test a component to immunity under all environmental conditions in all operating modes. Since IEC 61000-1-2 is generic to all electrical systems in all industries, it can only provide example test methods and generic testing levels. It heavily relies on developing testing parameters based on knowledge and experience with the particular product within its most probable environments. As stated in the previous section, the automotive EMC industry in general works together to harmonize standards based on experience over a large quantity of vehicles. The Bureau of Transportation Statistics reports that 8-15 million vehicles are sold yearly in the U.S. alone [9]. Unlike many other industries, the standards derived by the automotive industry include a significant amount of field experience. It is justifiable that the internal OEM test levels and test methods comply with the requirements stated in IEC 61000-1-2. All suggested immunity test parameters of IEC 61000-1-2 are already commonly performed in the automotive industry, with the exception of environmental factors and ageing.
The inclusion of environmental factors, such as temperature and humidity, during immunity testing is non-trivial. Often, EMC test chambers and equipment are not suitable for testing across the full temperature range required by automotive environments. However, environmental effects cannot be ignored when evaluating electric powertrains during a field immunity event. 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. The following two sections provide further details on how to consider environmental effects with respect to EMC.
The component itself is tested rigorously for functionality under extreme operating and environmental conditions. ISO 26262 requires that all safety relevant signals are also fully functional in these conditions. Additionally, ISO 26262 aids in filling in these temperature gaps through the evaluation of safety goal violations that can occur due to random hardware failures and by evaluating the hardware architecture. Immunity events causing a failure can be addressed using probabilistic metrics to analyze random failures and minimize their effects. Additionally, single-point, residual, and latent faults from the hardware architecture should be evaluated.
ISO 26262 provides two methods to evaluate random failures; a probabilistic approach, such as a Failure Modes Effects and Diagnostic Analysis (FMEDA), and a cut-set analysis, such as a Fault Tree Analysis (FTA). These methods must prove that a random hardware failure cannot cause a violation of the safety goals within a defined probability based on the ASIL rating of the system under consideration.
Generally, ISO 26262 will require a safety-critical system to address single-point, residual, and latent faults by either redundancy, moving the fault to a multiple-point fault, or by a high enough diagnostic coverage. The results of the FMEDA can be used to establish requirements for testing faults. This provides a systematic approach at recognizing and developing test cases.
Multiple-point faults require fault injection testing to verify that safety critical mechanisms remain in a safe state. Fault injection testing introduces faults to the hardware and studies the response. A list of common signal failure modes that are evaluated and tested are shown in Table 4. As can be seen, the failure modes considered during fault injection testing are also failure modes of a potential immunity event. These tests then support EMC activities. 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. This approach gets to the root of the impact to a failure, ensuring a safe outcome, and is independent of the source of the failure. As an example, the root cause of a signal being pulled low could be a cut circuit trace or an immunity event causing a dip in the voltage. Regardless, the fault injection test addresses the failure mode and verifies the proper reaction.
Table 4: Common signal failure modes
Many articles have been written with concerns on the lack of attention paid to immunity with respect to functional safety [10-12]. However, the guidelines provided by ISO 26262, when strictly enforced, alleviate many of the uncertainties raised in these articles. Before developing complex and impractical processes to analyze the risks to functional safety associated with EMC, ISO 26262 should be thoroughly reviewed and considered since it will be commonplace in the automotive industry.
Analysis: Temperature Effects
When evaluating electronic systems according to ISO 26262, it is important to understand the nuances of environmental exposure. Low-temperature conditions provide a useful example. For many power electronic components in electric powertrains, such as an inverter, true low-temperature conditions are only prevalent at start-up conditions after a cold-soak (e.g., overnight in a cold garage). Even very efficient electrical powertrains incur thousands of watts of losses, which are manifested as heat within the electronic components. Due to this heat generation, the time interval in which electrical powertrain component remain at the ambient low temperature is very short in comparison to the entire drive cycle. This effect has a substantial impact on the exposure of electronic components to the worst-case low temperature condition.
To illustrate this dynamic, a test was conducted with a pure EV powertrain at -20° C ambient temperature. A load of 3 kW was applied, which is relatively small in comparison to real propulsion loads. Due to the effect of losses, the inverter’s IGBT heated up to 45° C at a rate of 30° C/minute. The coolant temperature increased at a rate of 4.5° C/minute. Based on this, even at -40° C the inverter will heat to above ambient temperature within minutes and the entire cooling system in less than 15 minutes. Taking into consideration the frequency of a component’s exposure to such extreme temperature conditions, the risk of exposure to an immunity event becomes very small considering the probability of the injection during this small time window of the vehicle’s operation. All of these factors must be taken into consideration when conducting the hazard analysis and risk assessment.
For the first time, ISO 26262 provides a standardized risk analysis framework to account for all of these factors in an automotive production and development setting.
To elaborate further on the condition of low temperatures, consider the following example. A powertrain controller has an external emergency signal used to place the controller into a safe state in the event an unintentional acceleration event occurs. A decoupling capacitor between the signal and reference is used to secure the line from external immunity field events and is compliant to all EMC immunity requirements, assuming the capacitor maintains its specified capacitance. Consider a worst-case environment such as the region of Jokkmokk, Sweden in Lapland. This area is commonly used by a number of OEMs for winter testing. It resides along the Arctic Circle and has a yearly average temperature of approximately 0 degrees Celsius. Assuming the parameters illustrated in Table 5 and the average minimum temperatures of Jokkmokk, the capacitance of the capacitor could be below the necessary capacitance for 15% of the vehicle’s operating time. However, the risk of exposure to an external immunity field is less than 1% and the probability of needing the emergency signal is also less than 1%. Therefore the exposure for this particular example becomes an E0 (extremely unusual) of E1 (occurs less often than once a year for the great majority of drivers). According to Part 3 of ISO 26262, this particular scenario of cold temperature operation may be a QM or ASIL A.
Table 5: Parameters used for cold temperature example
Environmental extremes on the other end of the spectrum must also be considered. A similar analysis should be conducted as was shown in the cold temperature case. In the case of hot temperatures, elevated temperatures are naturally tested on a vehicle (system) level since the duration of vehicle EMC testing is sufficiently long enough that the entire powertrain will heat up to a point where the vehicle’s cooling system will be activated. Temperatures in the cooling system beyond a specified region, for example 90° C, would indicate a failure in the cooling system and would therefore produce a warning indication to the operator. A warning lamp already indicates to the operator that the continuation of driving must be taken with caution. When temperatures get too high, the powertrain will be reduced to zero torque. When considering these factors, the actual gaps in testing become small.
A full hazard analysis and risk assessment and FMEA should be conducted before over specifying immunity testing and requirements for a component. If the outcome proves that further testing is required, then the specific tests should be arranged between the safety manager and responsible EMC team. An example test could be conductive immunity testing beyond the operating temperatures of the component as detailed in SAE J2628 [13].
Case Study: Ageing Effects
Electrical components typically degrade in performance over time and after considerable usage. It is difficult to evaluate the impact of ageing with respect to EMC and functional safety due to the numerous parameters that must be considered and the lack of specific ageing data of each part within a component. Therefore the hazard analysis and risk assessment do not properly cover the risks involved with ageing, and actual testing is required.
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 DUT was previously tested during the development phase and met all immunity requirements. The first module was from a vehicle over five years old with over 80,000 miles. The second module was from a vehicle over three years old with over 35,000 miles. Both modules displayed similar corrosion damage. In this test case, both modules passed the OEM’s immunity tests as shown in Table 6.
Table 6: Immunity test performed on pre- and post-ageing DUT
The impact of component and vehicle ageing can and should be addressed to ensure functional safety. All components and vehicles undergo numerous accelerated lifetime and durability testing. Following these ageing tests, the vehicle should be tested again during development against the immunity requirements with specific focus on functional safety items and verification of the properly functioning safe state mechanism. Currently, immunity testing of vehicle durability is not commonplace across the industry. It is recommended to improve the lessons learned by establishing a shared and open testing forum for vehicles’ durability immunity testing among the OEMs. In addition to testing durability and field components, conducting tests beyond the operating temperature ranges, as specified in SAE J2628, can also simulate some effects of ageing components.
Considerations to EMS for Functional Safety
Electric powertrains are generally assigned a high ASIL rating due to the high severity and probability of a hazardous event relating to their direct impact on vehicle propulsion. Some critical signals for immunity testing include the speed sensor, current and voltage sensors, torque relevant messages, and signals related to the safe shutdown of the powertrain in faulted conditions. Other aspects of the powertrain need to also be considered, such as the type of electric motor. Permanent magnet (PM) motors can add additional risks due to the back emf created by the rotating magnets. A high braking torque due to high current flow can be produced when the back emf voltage is greater than the high voltage (HV) battery if the shutdown of the electric powertrain is not properly performed with PM motors. Not only do the critical signals have to be monitored during immunity testing, but also the vehicle’s safe reaction to a failure. All such potential hazards should be defined and identified during the hazard analysis and risk assessment and FMEA. These potential hazards should be included in the safety concept of the component or system.
EMC, to some degree, needs to be considered as one of many possible causes of failure. When this approach is taken, many of the risks associated with an immunity event are naturally covered through the normal ISO 26262 process. It is believed that ISO 26262 does not introduce revolutionary changes to the current OEM EMC process; however additional activities are still required. The following items are proposed to bring the current EMC processes into ISO 26262 compliance:
- Align safety critical activities between the EMC test and development engineers and the safety manager. A kick-off meeting prior to development is required, along with continual update meetings.
- Support the hazard analysis and risk assessment by providing feedback on failure modes due to immunity and ESD events. Verify that the proposed fault injection tests also cover failures associated with EMC. In particular, common-cause failures should be identified. Analyze each safety function against environmental conditions, such as extreme temperatures, to determine if additional measures and testing are required.
- Create a test plan to specifically monitor and test the functional safety relevant signals and functions. When higher levels are allowed by the EMC specification, they should be used on functional safety items. Any redundancy design for safety mechanisms allowing the vehicle to go to a safe state must be emphasized. Additional orientations or test cases may be required based on the safety analysis.
- Develop a plan for documentation and traceability of EMC related documents, including test reports and analysis. The safety manager should always be informed of any non-compliance issues.
- Add in ageing immunity testing during development. Establish a shared and open forum with other OEMs and suppliers to increase the lessons learned in the effects of ageing and immunity events.
- Evaluate internal component and vehicle requirements to confirm compliance to all EMC and ESD tests required by ISO 26262, shown in Table 3.
Table 7 provides a comparative summary between present EMC processes and updated processes to consider ISO 26262 requirements. Not everything shown in the new EMC processes is necessarily required for every component and system. Every company must evaluate the necessary changes to their processes based on the specific product. Companies working together can further align the activities and reduce the required effort.
Table 7: Comparison of present EMC processes and new proccesses to include ISO 26262 requirements
*Additional tests that could be required as an outcome of the hazard analysis and risk assessment.
Conclusion
ISO 26262 allows for a common automotive systematic approach to analyzing and evaluating risks for functional safety associated with EMC events. The standard process defined by ISO 26262 inherently addresses a number of risks associated with EMC and considers EMC as one of numerous possible failure modes. Today’s standard automotive EMC processes and standards follow the majority of ISO 26262 requirements. However, additional processes and activities are required to gain compliance with the standard’s overall requirements. These include assignment of a safety manager who can oversee the activities related to safety-critical functions, structured hazard analysis and risk assessment, inductive and deductive safety analysis, and required fault injection testing. 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.
References
- ISO DIS 26262:2011, “Road vehicles – Functional safety,” International Organisation for Standardisation, vol. 43.040.10, 26262, under publication.
- ISO DIS 26262:2009, “Road vehicles – Functional safety,” International Organisation for Standardisation, vol. 43.040.10, 26262, approval stage.
- IEC 61508:2010, “Functional safety of electrical/electronic/ programmable electronic safety-related systems,” International Electrotechnical Commission, ed. 2.0.
- IEC 61000-1-2:2008, “General – Methodology for the achievement of functional safety of electrical and electronic systems including equipment with regard to electromagnetic phenomena,” International Electrotechnical Commission, ed. 2.0.
- EMC-CS-2009.1, “Electromagnetic Compatibility Specification For Electrical/Electronic Components and Subsystems,” Ford Motor Company website, available: http://www.fordemc.com.
- GMW3097, “General Specification for Electrical/Electronic Components and Subsystems, Electromagnetic Compatibility,” General Motors Corporation internal document.
- CS-11979, “Chyrsler/Fiat Electrical and EMC Performance Requirements – E/E Components,” Chrysler Group LLC internal document.
- “Standardized E-Gas Monitoring Concept for Engine Management Systems of Gasoline and Diesel Engines,” Work Group EGAS, version 4.0, 2007.
- National Transportation Statistics, “The Transportation System,” US Bureau of Transporation Statitstics website, available: http://www.bts.gov.
- K. Armstrong, “EMC for the Functional Safety of Automobiles – Why EMC Testing is Insufficient, and What is Necessary,” 2008 IEEE International Symposium on Electromagetic Compatibility, Detroit, MI, August 18-22, 2008.
- W. Grommes and K. Armstrong, “Developing Immunity Testing to Cover Intermodulation,” 2011 IEEE International Symposium on Electromagetic Compatibility, Long Beach, CA, August 14-19, 2011.
- S. Wang, “Improve Vehicle’s Functional Safety with an Approach Investigating Vehicle’s Electromagnetic Interference with its Functional Safety,” 2011 IEEE Vehicle Power and Propulsion Conference, Chicago, IL, September 6-9, 2011.
- SAE J2628, “Characerization, Conducted Immunity,” Society of Automotive Engineers International, June, 2007.
Jody J. Nelson and William Taylor work at kVA LLC in Greenville, SC, USA and can be contacted at jody.nelson@kvausa.com and bill.taylor@kvausa.com, respectively.
Robert Kado works with the Chrysler Group LLC in Auburn Hills, MI USA and can be contacted at rk381@chrysler.com.