Connected vehicle technologies aim to tackle some of the biggest challenges of transportation industry in the areas of safety, mobility, and environment. Vehicle-to-Vehicle (V2V) or Vehicle-to-Infrastructure (V2I) wireless communications enables a vehicle to: sense threats and hazards with a 360 degree awareness of the position of other vehicles; calculate risk; issue driver warnings; or take preventive actions to avoid and mitigate crashes. Evolving wireless technologies and associated multi-antenna systems contribute to an ever-increasing need for performance testing in order to ensure a highly reliable performance and seamless quality. Dangers of poor performance must be carefully evaluated and managed: it is imperative that potential risks are quantified, mitigated and managed to be at very low levels.
Electromagnetic interference (EMI) is a common problem in power electronics systems. Pulse-width modulation (PWM) control of semiconductor devices in a power converter circuit creates discontinuity in voltage and current with rich harmonics over a broad frequency range, creating both conducted and radiated noise. The increase in switching speed enabled by new power semiconductor devices helps to reduce converter size and reduce switching losses, but further exacerbates the EMI problem. Complying with regulatory EMI emission limits requires the use of EMI filters in almost all power converter designs, and EMI filters are often the dominant elements for system volume,weight, and cost. Electromagnetic interference (EMI) filtering is a critical driver for volume and weight for many applications,particularly in electric vehicle and other mobile platforms.
Electromagnetic compatibility (EMC) is getting more important in power converters and motor drives as seen in hybrid electric vehicle (HEV) to achieve higher reliability of vehicle and its components. Electromagnetic interference (EMI) of all the electric components for vehicle is evaluated and validated at component-level test bench. However, it is sometimes observed that the EMI level of components is changed due to the difference of configuration (cable routing, connecting location etc.) because the component-level test is not always identical with vehicle-level test. In this presentation, a vehicle-level EMC simulation methodology is introduced to estimate radiated emissions from a vehicle. Also, the comparison between the simulation and measurement results is presented and discussed.
Electromagnetic Compatibility Measurement Procedure for Vehicle Components - Part 13: Immunity to Electrostatic Discharge
This SAE Standard specifies the test methods and procedures necessary to evaluate electrical components intended for automotive use to the threat of Electrostatic Discharges (ESDs). It describes test procedures for evaluating electrical components on the bench in the powered mode and for the packaging and handling non-powered mode. A procedure for calibrating the simulator that is used for electrostatic discharges is given in Appendix A. An example of how to calculate the RC Time Constant is given in Appendix B Functional Performance Status Classifications for immunity to ESD and Sensitivity classificatins for ESD sensitive devices are given in Appendix C. Sensitivity classifications for ESD sensitive devices are given in Appendix B.
The standard will apply to (but not necessarily be limited to) cables, line impedance stabilization networks, pre-amplifiers, attenuators, current probes, etc.
Performance Levels and Methods of Measurement of Electromagnetic Compatibility of Vehicles, Boats (up to 15 m), and Machines (16.6 Hz to 18 GHz)
This SAE Standard covers the measurement of radio frequency radiated emissions and immunity. Each part details the requirements for a specific type of electromagnetic compatibility (EMC) test and the applicable frequency range of the test method. The methods are applicable to a vehicle, boat, machine or device powered by an internal combustion engine or battery powered electric motor. Operation of all engines or motors (main and auxiliary) of a vehicle, boat, machine or device is included. All equipment normally operating when the vehicle, boat, machine or device is in operation is included. Operator controlled equipment is included or excluded as specified in the individual document parts. As a special case, CISPR 12 applies to battery powered floor finishing equipment, but robot carpet sweepers are excluded. By reference, IEC CISPR 12 and CISPR 25 are adopted as the standards for the measurement of vehicle emissions.
This SAE Standard specifies the ESD test methods and procedures necessary to evaluate electronic modules intended for vehicle use. It describes test procedures for evaluating electronic modules in complete vehicles. A procedure for verifying the simulator that is used to generate the electrostatic discharges is given in Appendix A. Functional status classifications for immunity to ESD are given in Appendix B.
This specification covers constant displacement hydraulic motors, generally remotely mounted, using hydraulic fluid under pressure as the energy transfer medium for driving various accessories. Hydraulic motors shall be suitable for use in aircraft hydraulic systems conforming to and as defined in MIL-H-5440 and MIL-H-8891 as applicable.
Abstract This paper describes a high-speed electrical machine for an aircraft starter-generator. A surface mounted permanent magnet machine is designed to have minimal rotor losses and a novel cooling system for the stator. An inner stator sleeve is adopted to allow for a flooded stator whilst minimizing rotor windage losses. Different slot-pole combinations are compared in view of attaining an optimal combination that provides minimum losses whilst satisfying the electromagnetic, mechanical and thermal constraints.
Impact of Cable Bundles and Systems' Integration Rules Dedicated to Metallic Aircraft on the Electromagnetic Immunity of Systems in Composite Aircraft
Abstract Advanced commercial aircraft increasingly use more composite or hybrid (metal and composite) materials in structural elements and, despite technological challenges to be overcome, composites remain the future of the aviation industry. Composite and hybrid aircraft today are equipped with digital systems such as fly by wire for reliable operations no matter what the flying environment is. These systems are however very sensitive to electromagnetic energy. During flight, aircraft can face High Intensity Radiated Fields (HIRF), static electricity, or lightning. The coupling of any of these threats with airframe structure induces electromagnetic energy that can impair the operation of avionics and navigation systems. This paper focuses on systems susceptibility in composite aircraft and concludes that the same electromagnetic rules dedicated to all metal aircraft for systems and wiring integration cannot be applied directly as such for composite aircraft.
This AIR intends to better document and tabulate electrical load dynamics that influence power source capacity, power quality and stabiltiy.
This SAE Aerospace Recommended Practice (ARP) is an application guide for fixed and variable displacement hydraulic motors. It provides details of the characteristics of fixed and variable displacement hydraulic motors, architectures, circuit designs, controls, and typical applications. The applications include airborne and defense vehicles with emphasis on high performance applications.
This SAE Aerospace Standard (AS) establishes the minimum performance standards for equipment used as secondary alternating current (AC) electrical power sources in aerospace electric power systems.
This SAE Aerospace Recommended Practice (ARP) defines lightning strike zones and provides guidelines for locating them on particular aircraft, together with examples. The zone definitions and location guidelines described herein are applicable to Parts 23, 25, 27, and 29 aircraft. The zone location guidelines and examples are representative of in-flight lightning exposures.
SAE ARP to provide guidance and best practices for demonstrating civil aircraft electromagnetic compatibility (EMC). Incorporate EMC guidance for large transport airplanes, business airplanes, small airplanes, small helicopters, and transport helicopters. Provide guidance that considers compliance with aircraft safety requirements, and also considers intended performance of non-required and non-essential aircraft systems. Provide guidance on aircraft equipment EMC qualification, aircraft system and wiring installation, and aircraft EMC tests.
This SAE Standard defines a method for evaluating the immunity of automotive electrical/electronic devices to radiated electromagnetic fields coupled to the vehicle wiring harness. The method, called Bulk Current Injection (BCI), uses a current probe to inject RF onto the wiring harness in the frequency range of 1 to 400 MHz. BCI is one of a number of test methods that can be used to simulate the electromagnetic field.
This SAE Aerospace Recommended Practice (ARP) establishes software capability guidelines for computer controlled test equipment, hereinafter referred to as automatic test equipment (ATE), for testing hydraulic components. A typical ATE system is shown. The items herein have been selected as potential features which may or may not be applicable to a particular application. This document does not address software development requirements, qualification procedures, or hardware design requirements, but encourages users to refer to existing documents for guidance on such issues.
Electromagnetic Compatibility Measurement Procedure for Vehicle Components - Immunity to AC Power Line Electric Fields
This SAE Recommended Practice covers the recommended testing techniques for the determination of electric field immunity of an automotive electronic device when the device and its wiring harness is exposed to a power line electric field. This technique uses a parallel plate field generator and a high voltage, low current voltage source to produce the field.
Bench Level Automotive Electrical and Electromagnetic Compatibility Validation Test Process Improvements (Analysis of Survey Results from Test Laboratories)
Abstract In an effort to reduce the cost and time associated with bench level automotive electrical and electromagnetic compatibility (EMC) validation tests, a survey was created to request advice from the test labs that perform this testing. The survey focuses particularly on the development of the test plan document and the preparation of the test setup. The survey was sent to a targeted group of individuals with experience in performing this type of testing. The invitees work at laboratories that represent the majority of labs in the world that are authorized to perform component electrical / EMC validation testing for automotive original equipment manufacturers (OEMs). There were a significant number of responses; it is possible that representatives from all of the invited laboratories responded. The survey results provide demographic information about the test labs and their participants.
Abstract There are certain products which ask for Isolation requirement to be met. To meet this requirement, we usually make use of Isolated DC - DC converter which is an easy & compact solution. Usually this leads to severe electromagnetic interference issues which badly impact the Certification/Qualification of the product. This is due to the in-built transformer in the Isolated DC - DC converter device, which switches at high frequency, in the range of mega hertz. Considerable amount of time and money is spent in debugging and resolving these issues. This paper is intended to address these issues with solutions, which will help the designer to take care at the Design stage, thereby saving time & money, the important parameters of the project cost. A set of experiments & analysis were conducted to find the root-cause of the issue.
In the sensitive automotive applications like the safety restraint systems (SRS), twisted lines can be used to link the components of the system because of their property of reduction of the electromagnetic interference (EMI) coupling. Compared to the parallel lines, the twisted lines present the drawback to consume more copper in their manufacturing due to the greater length of their conductors. A parametric study based on the numerical modeling and the measurement of twisted lines is conducted in order to analyze the effect of the twisting pitch and of the untwisted part of these lines on the level of EMI coupling. This study will enable to optimize these two parameters in order to reduce the level of EMI coupling as well as the length of the conductors of the lines.
Abstract This work presents a physical model that calculates the efficiency maps of the inverter-fed Permanent Magnet Synchronous Machine (PMSM) drive. The corresponding electrical machine and its controller are implemented based on the two-phase (d-q) equivalent circuits that take into account the copper loss as well as the iron loss of the PMSM. A control strategy that optimizes the machine efficiency is applied in the controller to maximize the possible output torque. In addition, the model applies an analytical method to predict the losses of the voltage source inverter. Consequently, the efficiency maps within the entire operating region of the PMSM drive can be derived from the simulation results, and they are used to represent electric drives in the system simulation model of electric vehicles (EVs).
This document is intended for use by manufacturers of aircraft, engines and Electronic Engine Controls [EECs] as a component change process and evaluation guideline. Its purpose is to provide an effective means of managing the modification of electronic hardware.
This Aerospace Recommended Practice (ARP) provides design and test requirements for factory precharged, welded bellows hydraulic accumulators.
This Hydrospace Information Report (HIR) identifies the general environmental considerations for the design, development, evaluation, and testing of advanced surface craft, submersible vehicles, and other marine craft. This HIR provides criteria on the environmental limits within which marine vehicles, related components, and associated equipment should operate satisfactorily and reliably. This HIR is intended for use as a guide for the development of specific environmental requirements to be included in detailed specifications for marine vehicles and associated equipment. Specific requirements are in a state of continual change as our knowledge of the ocean environment increases. The ocean environment varies with location and time. Changes in the ocean environment can occur not only on a seasonal basis but also monthly, weekly, daily, and in some cases even hourly.
This SAE Aerospace Information Report (AIR) considers the issue of power regeneration into the EPS of an aircraft. A series of options for dealing with this regenerative power are considered and arranged in categories. Advantages and disadvantages of each solution, including the existing solution, are included. Validated simulation results from representative Electrical Power systems are presented in order to demonstrate how some of the solutions may operate in practice and how power quality can be maintained during regeneration. The impact on changes to the electrical generation system are also highlighted in this AIR, as these changes may have an impact on the solution deployed and the wider impact on the design of engines and auxiliaries. This AIR reviews concepts and excludes detailed discussions on power system design. These concepts relate to the More Electric Aircraft, cover both AC and DC systems and can be applied to both normal operating conditions or as fault mitigation.
This SAE Aerospace Recommended Practice (ARP) provides guidance for substantiating the airworthiness of aircraft engine components. Generally these components are associated with the engine control system, the system or systems that allow the engine to provide thrust or power as demanded by the pilot of the aircraft while also ensuring the engine operates within acceptable operating limits. But these components may also include hardware and systems associated with engine lubrication, engine or aircraft hydraulic or electrical systems, aircraft environmental control systems, thrust reverser control, or similar aircraft or engine propulsion system functions. This paper develops the concept of using a 26 item matrix of environmental conditions for evaluating aircraft engine component airworthiness. This approach is compatible with current practices used in the industry and has been accepted by engine certification authorities as part of engine certification programs.
Gas compressors (air and other compressible fluids) have been used sporadically since the 1940's for various utility functions in aerospace applications. They have been used to provide power to gun purge and drive systems, engine or APU starters (recharge accumulators), reservoir pressurization, cockpit pressurization, braking systems, canopy seals, engine control divides, landing gear activation, and boosted flight controls (see Table 1). In current state-of-the-art aircraft, most pneumatic system power is extracted from a stage of compression in the turbo-jet engine. As more and more demands are put on new generation engines for fuel economy and performance there is an increasing need for a new source of pneumatic power. This document is intended to describe current state-of-the-art technology in compressors, define the limitations, discuss enhancements needed and attempt to predict the needs of the future.
This specification established (1) the common requirements for hydraulic units capable of functioning as starters and as pumps suitable for use in aircraft and missiles and (2) the methods to be used for demonstrating compliance with these requirements.
Investigating GSM Interference in Automotive Sound Systems Using State of the Art Electromagnetic Simulation
EMI (Electromagnetic Interference) is one of the major concerns today in the automotive industry. The main reason is that vehicles are using and depending more on electronic technology. The causes of electromagnetic interference problems are not only related to the ever-increasing number of embedded electronics systems in vehicles, but also to external electronic devices that are brought in to automobiles by drivers and passengers (e.g. cell phone, MP3 players, Bluetooth devices, portable video games). Even though these problems can cause serious issues on safety systems like the airbag, their symptoms are often noticed in a less harm way in the sound system. A very common EMI problem in automotive sound systems is a particular noise caused by devices that uses GSM (Global System for Mobile Communications) technology. Most of the cell phones and vehicle locators rely on GSM technology.