Browse Topic: Electric drives

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Study and Application of Gear Micro Modification of Electric Drive System15-16-01-00019/15/2022
Abstract The gear whine in the electric drive system of an electric vehicle is important and remains a challenge in developing novel electric vehicles. A gearbox dynamic model is established, and the effects of modification parameters on the sound pressure level, transmission error, and contact stress of the gear pair are introduced to reduce the gear whine. A multi-objective optimization study of four modification variables under multiple torque conditions is carried out by using transmission error and maximum contact stress as the objective functions. The eclectic programming method is imported to solve the convergence problem of multi-objective optimization. The influence of modification variables on objective functions is studied by establishing an approximate model of the optimal Latin hypercube design. Results show that the application of the multi-objective optimization method combined with the eclectic planning method for the micro modification of the gear can reduce the transmission error of multi-torque conditions, effectively reducing the gear whine noise in multiple torque conditions and improving the contact of the tooth surface.
Chen, Chen, Zhu, Linpei, Liu, Jing, Wei, Dan, Yu, Hao
Airport Electrical Power System HarmonicsAIR5387 (Current)9/23/2020
This SAE Aerospace Information Report (AIR) is intended to cover all airport 50 or 60 Hz electrical systems as well as all electrical utilization equipment that is attached to those systems.
AGE-3 Aircraft Ground Support Equipment Committee
Improved Customer Experience through Electric Vehicle Sound Enhancement2020-01-13614/14/2020
Electric Vehicles are typically thought of as being quiet and refined, but they do come with some unique N&V challenges. Some of these challenges include a natural sound that can be undesirable due to its tonal nature, presence of high frequency, discontinuities in sound, and characteristics and levels that do not always naturally increase with motor torque and vehicle speed. One approach to address those challenges is Electric Vehicle Sound Enhancement (EVSE) which is a software feature embedded within the infotainment system. EVSE can be used to improve the perception of the vehicle by enhancing the preferred natural sounds of the vehicle, masking unusual and annoying components of the sound and aurally conveying information related to the vehicle performance. A jury study was conducted to better understand how EVSE can be used to accomplish this. This paper will summarize a typical EVSE system and highlight some of the tools and methods that can be used to develop an EVSE tuning that mitigates unpleasant sounds while enhancing the customer experience without completely changing the vehicle DNA. Vehicle examples that mitigate issues and enhance the vehicle sound will be used to help describe the benefits and methods of EVSE.
Valeri, Frank, Pietila, Glenn
Vehicle Design Considerations Enabling High-Performance Charging2020-01-14404/14/2020
Customer requirements such as range anxiety and charging time are the driver for increasing the charging power of battery-electric vehicles (BEV). High-performance charging (HPC) theoretically enables time targets of faster than 30 kilometers (19 miles) recharging per minute. Due to physical limitations (i.e., current limits of the components) a charging power of more than 200 kilowatt arises the question of the voltage level required to fulfill the power demand. One possible approach to achieve a high charging power is increasing the battery voltage, i.e., increase the voltage level from 400 V to 800 V. This publication discusses the main aspects of charging by incorporating all high-voltage components in the vehicle. An increase of the voltage level and charging power affect all high-voltage components. The thermal management of the battery has to be considered. High-voltage vehicle architecture design considerations are discussed including thermal-management and battery-design aspects. Different charging characteristics from electric vehicles (EVs) available, are compared with an estimated fast charging profile which is based on theoretical background of available cells including consideration of physical and chemical limits (e.g., thermal-limits, cell-degradation). Additionally, higher-performance charging (HPC) also require consideration of the public charging infrastructure. Extending the technical point of view with customer values, the charging efficiency is considered including the infrastructure. Furthermore, customer acceptance and market forecasts are considered. Higher voltage levels enable higher power also for other components in the vehicle, such as the electric drives, high-voltage heaters, compressors and voltage converters. To determine the optimum voltage level, for a reference vehicle used in this paper, all those considerations are compared in the discussion. Focusing on the early development phase of a complete vehicle, criteria for conceptual design considerations are discussed incorporating the high-voltage vehicle architecture and the battery from the thermal point of view.
Paar, Christian Josef, Waser, Helmut Martin, Kreimaier, Heimo, Cuenca-Jaen, Inés, Eibler, Florian
Iterative Dynamic Programming Based Model Predictive Control of Energy Efficient Cruising for Electric Vehicle with Terrain Preview2020-01-01324/14/2020
As a global optimization method, dynamic programming (DP) can be employed to seek the optimal velocity with minimum energy consumption for EV on given driving cycles. Due to its terrible computational burden, conventional DP is not suitable for real-time implementation especially with higher dimensions. In this paper, we propose an iterative dynamic programming (IDP) approach to reduce computing time firstly. The IDP can obtain the optimal control laws alike the conventional DP by converging the optimal control strategy iteratively and save considerable computing time. Second, the developed IDP and model predictive control (MPC) are combined to establish a real-time cruising controller called IDP-MPC for an EV with terrain preview. In the predictive controller, we use the IDP to solve a constrained finite horizon nonlinear optimization problem. Finally, to assess the performance of the proposed cruising controller, simulation on a realistic urban expressway road terrain is implemented. Energy-saving potential of the IDP-MPC controller is explored by comparing to DP and constant speed (CS) cruising controllers. The comparative study indicates that the IDP-MPC controller can obtain near-optimal energy-saving capacity compared to DP controller.
Ju, Fei, Zhuang, Weichao, Wang, Liangmo, Wang, Qun
Series Fuzzy PID with Anti-windup Controller for Intelligent Vehicle2020-01-01134/14/2020
A series fuzzy PID controller with anti-windup scope (SFPCA) is proposed in this paper to address saturation nonlinear problem and control disturbance caused by uncertainty of actuator model. In order to achieve novel dynamic and steady-state performance, the fuzzy controller and PID controller are fused into series, which realizes excellent dynamic performance of fast response and low overshoot like pure fuzzy controller at the initial response stage, and the excellent steady-state performance of stable and no static difference like PID control at the later response stage. The Hurwitz low is employed to configure PID parameters and 49 rules are designed for fuzzy controller. Since the input of the actuator could not be infinite, the actuator being saturated for a long time could reduce the stability of system and, even lead to irreversible damage. Moreover, after exiting the saturation state, it is difficult to quickly recover to the fast and stable response state of the original system. Therefore, an anti-windup scope is meticulously developed to limit the system input to a reasonable range under the saturation state, and, in the unsaturated state, the original Fuzzy PID control is restored. In order to verify the performance of the algorithm, four comparison algorithms were adopted, including pure PD, pure PID, pure Fuzzy and series Fuzzy PID controller (SFPC), and two typical commands like step and sine are employed as desired signals. The experimental results show that the SFPCA has more excellent dynamic and steady performance than pure PD, pure PID, pure Fuzzy and series Fuzzy PID controller (SFPC).
Luo, Chao
Research on Control Strategy Optimization for Shifting Process of Pure Electric Vehicle Based on Multi-Objective Genetic Algorithm2020-01-09714/14/2020
With more and more countries proposing timetables for stopping selling of fuel vehicles, China has also issued a “dual-slope” policy. As electric vehicles are the most promising new energy vehicle, which is worth researching. The integration and control of the motor and gearbox have gradually become a hot research topic due to low cost with better performance. This paper takes an electric vehicle equipped with permanent magnet synchronous motor and two-gear automatic transmission without synchronizer and clutch as the research object. Through the action of the motor, gearbox and shift actuator in the shifting process, the whole vehicle dynamics is modeled in each stage of shifting, a method for determining a short-term driving style intensity factor for decision shifting is proposed, three evaluation indexes of the shift quality of electric vehicle are put forward, the control parameters affecting the shift quality are analyzed, and the mathematical relationship between the shift control parameters, the shifting time and the shifting impact are obtain. Besides, the NSGA-II algorithm is used to carry out multi-objective global optimization of the whole process of shifting to get Pareto optimal solution. Analyze the optimization results in combination with driving style, determine some thresholds and parameters of the drive motor and shift actuator action control during the shifting process, improve the shift control strategy, and finally complete the coordinated control of the shifting process of the electric drive system based on the active synchronization of the motor. The results show that the optimization effect is good. It provides a new idea for the shifting process control of the pure electric vehicles.
Lei, Yulong, Zhang, Jingxu, Fu, Yao, Jia, Fuchun, Wang, Binyu
Low-Inductance DC Power BusTBMG-361603/1/2020
Anew generation of power electronic conversion systems is being enabled by wide-bandgap (WBG) devices. Applications in civilian and defense sectors are already realizing improved power density and efficiency in power converters that utilize silicon carbide (SiC) and/or gallium nitride (GaN) switches; however, as semiconductor switches become capable of greater hold-off voltage, higher switching frequency, and higher junction temperature, limits on converter performance will depend on the remainder of the system: device packaging, filter components, and thermal management, as examples.
Electrifying GM20AUTP03_013/1/2020
After two decades of hybrid development, General Motors puts its full futurepropulsion focus on BEV technology-with vertically integrated development and production. General Motors' long, convoluted journey toward vehicle electrification has finally arrived at an earlier-than-expected destination: total commitment to a battery-electric future. GM is officially “all in” on BEVs as its future propulsion strategy, with some 20 electric models slated for launch by 2023. The Detroit-Hamtramck plant is being transformed into GM's first dedicated EV production facility. Its product cadence, set to begin within the year, will be led by electric Chevrolet and Cadillac crossovers. Joining them is GM's first electric pickup that will resurrect the still-popular Hummer nameplate within the GMC brand. The company aims to sell one million EVs globally by 2026, asserts CEO Mary Barra, while it continues to evolve its profit-driving IC-powered trucks and crossovers (and develop self-driving vehicles with tech partner Cruise). It's an ambitious plan that ends GM's 20 years of hybrid-vehicle development. That extensive HEV roster included belt-alternator “electric assist” systems; “Two-Mode” transmissions co-developed with Daimler and BMW; 42-volt starter-generator pickup trucks and two generations of Volt range-extender hybrids that included Volt's Cadillac spinoff, the obscure ELR.
Replacement of a 50cc Two-stroke Engine with an Electric Powertrain2019-32-06231/24/2020
As global regulations look to create a dramatic reduction in CO2 emission and other forms of pollution, companies with products that rely on engine technology must be ready to take on the electrification challenge. Applications that remain using two-stroke engine technology continue to exist due to their very high power density requirements. However, their history of higher pollution compared to four-stroke engines makes them a target to be regulated out of existence. Such high power two-stroke applications include high performance off-road motorcycles. In this type of product, electrification can solve not only pollution challenges but market challenges, such as ridership and public perception. By addressing the core problems presented by the two-stroke engine and turning challenges into opportunity, a strong attraction is created to convert a two-stroke engine motorcycle to an electric vehicle. With Automotive electric vehicle technology paving the way, the basis for cost effective electric motorcycle powertrain is explored for a 50cc off-road motorcycle application. The 50cc engine and motorcycle represent a special product where size, performance, and cost have a high sensitivity. The 50cc product also represents an area of great opportunity for the product as it is connected to the youth riding segment that establishes the future of motorcycle riding. With both strong opportunity and strong challenges, the electrification solution for a 50cc application provides broad justification for mass market adoption across the motorcycle industry. Challenges will be presented towards a OEM level product where design change is to be minimized without compromising performance. Various challenges include system design, packaging, supply chain, product lifecycle, competition readiness, safety, and cost. Opportunities will be discussed in the context of how the electrified powertrain can create a better product for the rider and solve challenges to enable the next generation of motorcycling. These opportunities include manufacturing advantages, environmental harmony, and new features.
Beeker, Jesse
Development of Voltage Control Unit Using a Coupled Inductor with a New Structure for Plug-In Hybrid Vehicle2019-01-231112/19/2019
Honda has developed an electric powertrain for the new model plug-in hybrid vehicle. In order to realize the EV performance, it was necessary to increase the power output of the high-voltage DC-DC converter to boost the battery voltage (referred to as a “Voltage Control Unit (VCU)” below). An interleaved circuit using the newly developed coupled inductor was employed to reduce the magnetic flux leakage to the exterior as the method of increasing the power density of the VCU. The application of the inductor has increased the continuous power density of the VCU approximately 2.8-fold in comparison with the conventional unit employed in previous Honda hybrids.
Komatsuzaki, Akitomo, Choji, Tatsuya, Hashino, Satoshi
Research on Test Method for Shielding Effectiveness to Cable of Vehicles2019-01-507011/4/2019
With the development of electric vehicles (EVs), hybrid electric vehicles (HEVs) and fuel cell vehicles (FCVS), high voltage and large-current are applied to cables. Therefore, it is important to avoid electromagnetic compatibility (EMC) problems of cables, and a measurement methods is necessary for the shielding effectiveness of shielding cables. This paper discusses the existing test methods of cable shielding effectiveness and summarizes the main problems and deficiencies. Then, according to the practical requirements of high voltage cable testing, the direct injection method based on the national standard GB/T 18655-2018 (modified international standard CISPR 25) is proposed. The test method is verified by constructing a practical test platform. The test result show that the platform built can meet the test requirements of the new energy vehicles (NEVs) GB/T 18387 test frequency band 150k~30MHz, and can also meet the test requirements of the 150k~108MHz frequency band of the key component conducted emission of NEVs.
Jiang, Li, Chen, Xichen, Liu, Haiming, Wu, Zaiyuan, Wang, Yun
Research on the EMF Impact of Vehicles on Human Health2019-01-504811/4/2019
In recent years, with the rapid development of new energy vehicles, the impact of electromagnetic field (EMF) from vehicles to human body has become a growing concern of consumers. The national standard GB/T 37130-2018 "Measurement methods for electromagnetic field of vehicle with regard to human exposure" was officially released at the end of 2018, which was attracted extensive attention of vehicle manufacturers, testing structures and consumers. GB/T 37130-2018 specifies the test methods for low frequency EMF of vehicles. In this paper, a comparison of the main technical contents between GB/T 37130-2018 standard and International electro technical commission (IEC) standard, Japanese automotive standard organization (JASO) and other relevant standards is present; and then a general survey based on the test method specified in GB/T 37130 standard is carried out by comparing the test results of multiple vehicle models, which can give the reader an intuitive understanding of the EMF level of vehicle.
Jiang, Li, Zhang, Xu, Cai, Shurong, Sun, Kaiyi, Guo, Chen
Development and Testing of Electric Microcar for Indian Cities2019-28-000810/11/2019
Population growth, rapid urbanisation and compounding effects of adding personal vehicles have resulted in increasing the urban air pollution in major Indian cities. Apart from the rising concerns about the urban air pollution, the increasing traffic and lack of parking space difficulties are promoting energy efficient small vehicles. Hence, there is a need to develop a new environmental friendly microcar that relatively affordable and easily manoeuvrable in bigger cities. Electric microcar is one of the most promising options to improve the near term sustainability for personal transportation in cities. This paper mainly presents the development of two seater electric microcar suitable for city driving requirements followed by road test. A mathematical modelling with reference to the urban cycle (Part-one) of modified Indian driving cycle (MIDC) is also carried out for the evaluation of energy and power requirements of electric microcar. The developed electric microcar has been tested on road with the help of the MIDC simulator kit. Results revealed that the developed prototype has demonstrated about 50 km range after one full charge.
Shaik, Amjad, Talluri, Srinivasa Rao, Tappa, Raju, Ratlavath, Ramu
Design and Analysis of Sigma Z-Source Inverter for PV Applications2019-28-012310/11/2019
Traditional Voltage Source Inverter (VSI) produces lesser output voltage than the input and causes shoot-through due to the gating of the semiconductor device connected in same leg. The ZSI is used to overcome the inadequacies of VSI. The ZSI has been extensively used in electric drives, PV system and UPS. The conventional ZSI suffers some disadvantages like restricted boost capability, discontinuity in input current and large inrush current. These limitations are overcome by using a transformer which replaces the inductor in the impedance source network. In high-voltage gain applications, the single transformer-based ZSI topologies requires more turns ratio which requires large size transformer. For improving the boost capability, the TZSI is used. The Z-source network of the TZSI constitutes two transformers with low turns ratio. TZSI has certain demerits such as restricted boost capability, high inrush current and discontinuity in the input current. However, TZSI requires high turns ratio to increase the boost capability. Thus, the modified ZSI, i.e. sigma ZSI is investigated in this paper. The sigma ZSI has the advantage of having reduced turns ratio with enhanced boost capability.
Nallathambi, Kalaiarasi, Rangarajan, Uthra, Daniel, Anitha
EDITORIAL: Word on the street at COMVEC19TOFHP10_0610/1/2019
Last month's SAE COMVEC technical conference in Indianapolis welcomed many high-level engineering leaders who spoke to show-goers about a range of important topics impacting on- and off-highway vehicles. The two main tracks at the event, Fueling the Future and Charging the Future, covered various alternative propulsion and electrification trends and technologies (see features on pages 22 and 29). And of course, automated driving systems and the best approaches to achieving highly automated vehicles were on the docket.
Gehm, Ryan
Target Setting Process for Hybrid Electric Drives Using TPA, Jury Study, and Torque Management2019-01-14536/5/2019
The idea of improved efficiency without compromising the “fun to drive” aspect has renewed the auto industry’s interest toward electrification and hybridization. Electric drives gain from having multiple gear ratios which can use advantageous operating set points thus increasing range. Furthermore, they benefit significantly from frequent decelerations and stopping as is experienced in city driving conditions. To recuperate as much energy as possible, deceleration is done at high torque. This presents an interesting but serious sound quality issue in the form of highly tonal whine harmonics of rapidly changing gears that do not track with vehicle speed thus being objectionable to the vehicle occupants. This paper presents an NVH target setting process for a hybrid electric transmission being integrated into two existing vehicles, one belonging to the premium segment and another aimed at enthusiasts with off-road applications. The demand for power has shifted from mechanical domain into electrical domain, and as such, the solution to electric drive NVH issues also lay partly, in the way these drive systems are calibrated. A time-domain Transfer Path Analysis (TPA) model was developed for both vehicles, by virtually installing the hybrid transmission into the vehicle, thus predicting interior noise in several gears and simulating the brake regen coast downs at varying torque levels. Road and wind noise masking was added to these predictions taking care that the summations were correctly done at same vehicle speeds for which a program was written using a commercially available numerical computing tool. Extensive jury studies were then conducted to determine NVH no-fly zones and the torque management strategy for the two vehicles during brake regen events. Requirements and strategy for the two vehicles were different since they presented different levels of road and wind noise masking. To validate the NVH targets, another jury compared the finalized strategy with a premium target vehicle fitted with a similar hybrid system. This target-setting approach was useful in getting an upfront idea of the NVH risks without any system modifications. It then circumvented the need of re-developing expensive acoustic package and/or gear optimization that would be otherwise needed to mitigate the risks, with co-operation from calibration teams, while still being able to meet their regenerative braking targets in every gear for the two vehicles.
Singh, Vinod, Parbat, Aniket, Charan, Anil
Test and Analysis of Electromagnetic Noise of an Electric Motor in a Pure Electric Car2019-01-14926/5/2019
Compared with the low-frequency ignition order of mechanical and combustion noise of an internal combustion engine, the noise of electric drive assembly of electric vehicles is mainly the high-frequency whining noise generated by electromagnetic forces of motors and gear meshing of reducers, as well as the high-frequency umbrella-shape noise generated by DC/AC pulse width modulation. Although the radiated sound power of these high frequency noise is far less than that of an internal combustion engine, the high frequency noise of the motor and the reducer is subjectively quite annoying. This paper studies the characteristics of electromagnetic noise of a permanent magnet synchronous motor in an electric car. By testing and analyzing of noise sources of an electric motor in the car and on a test rig, the spatial order characteristics and amplitude-frequency characteristics of the electromagnetic forces are revealed. The noise orders are multiples of the number of motor poles. The most critical order is 48th order, and its spatial order is 0th order. The peak of this 48th order is due to the stator’s 0th breathing mode being excited by the 48th frequency order electromagnetic force. Through theoretical calculation of the air-gap magnetic field and electromagnetic force wave, it is concluded that the 48th order electromagnetic force results from interaction of the rotor magnetic field and slotted core of the stator, and due to stator current harmonics. In this study, it is demonstrated by increasing the air gap by 0.2mm experimentally, the electromagnetic force can be reduced, resulting in the reduction of the motor noise by 5dB.
Kang, Qiang, Gu, Perry, Gong, Chao, Zuo, Shuguang
NVH Aspects of Electric Drive Unit Development and Vehicle Integration2019-01-14546/5/2019
The automotive industry continues to develop new powertrain and vehicle technologies aimed at reducing overall vehicle-level fuel consumption. Specifically, the use of electrified propulsion systems is expected to play an increasingly important role in helping OEM’s meet fleet CO2 reduction targets for 2025 and beyond. This will also include a strong growth in the global demand for electric drive units (EDUs). The change from conventional vehicles to vehicles propelled by EDUs leads to a reduction in overall vehicle exterior and interior noise levels, especially during low-speed vehicle operation. Despite the overall noise levels being low, the NVH behavior of such vehicles can be objectionable due to the presence of tonal noise coming from electric machines and geartrain components as well as relatively high shares of road/wind noise. In order to ensure customer acceptance of electrically propelled vehicles, it is imperative that these NVH challenges are understood and solved. This paper discusses various aspects of the EDU NVH development process. This will include a discussion of the NVH target cascading methodologies for EDUs, followed by a description of the EDU development and vehicle NVH integration process. Utilizing examples, specific aspects of EDU design to assure acceptable NVH behavior from the EDU will be discussed. The use of advanced simulation techniques for electric machine noise as well as geartrain-related noise will be demonstrated using examples. Finally, aspects of EDU “source” noise/vibration measurements and integration into the vehicle to assure refined vehicle-level NVH behavior will be illustrated using examples from relevant case studies.
Wellmann, Thomas, Tousignant, Todd, Govindswamy, Kiran, Tomazic, Dean, Steffens, Christoph, Janssen, Peter
Structural Vibration and Acoustic Analysis of a 3-Phase AC Induction Motor2019-01-14586/5/2019
This paper aims to study the NVH and acoustic performance of a 3-phase AC induction motor in order to develop an approach to reduce the magnetic component of noise from an electric motor in an electric vehicle (EV). The final goal of this project is to reduce the magnetic component of sound from the motor by making modifications to the end bracket of the motor housing. EVs are being considered the future of mobility mainly due to the fact that they are environment-friendly. As many companies are already investing in this technology, electric drives are set to become extremely popular in the years to come. The heart of an EV is its motor. Modern electric vehicles are quiet, furthermore with the lack of an IC engine to mask most sounds from other components, the sound from the electric motor and other auxiliary parts become more prominent. The primary source of electromagnetic noise in a motor arises from magnetic flux variations in the air gap which interfere with the resonant frequencies of the stator core. These flux variations result in a time-varying force that acts on the stator core or teeth and causes it to deform. This paper studies the radial and tangential components of this force and how these structural vibrations can be dampened by using a modified end bracket with properties that can help reduce the overall sound radiated by the motor. The paper shows a process to analyze the sound radiated from an electric motor in three broad steps. First, an impact hammer test is performed on the stator and assembled motor to analyze its resonant frequencies. Second, the operational deflection shapes of the motor in the operating condition are extracted to visualize the housing deformation and identify resonant frequencies being excited. Finally, a sound intensity analysis is conducted to calculate sound pressure levels at different frequencies.
Krishnasarma, Anand, Taylor, Allan, Baqersad, Javad, Poozesh, Peyman
Aeroacoustic Modeling of an eVTOL Slowed Rotor Winged Compound AircraftF-0075-2019-144545/13/2019
Piasecki Aircraft Corporation (PiAC) and Continuum Dynamics, Inc. (CDI) are investigating noise levels of the PA890, an emergent eVTOL slowed rotor winged compound (SRWC) configuration using the CHARM/PSU-WOPWOP aeroacoustic analysis. While the adoption of electric drive eliminates engine noise, this design allows several operational degrees of freedom that permit it to further mitigate noise mechanisms associated with conventional single rotor helicopters, including: lift compounding to offload the main rotor; reduction of main rotor RPM in cruise; and a dual mode (antitorque/pusher) tail rotor that allows alternate modes of operation for targeted forward flight conditions, with significant potential for noise reduction. This paper provides an overview of an acoustics analysis of the PA890 eVTOL SRWC configuration, including a comparison to an existing single rotor civil helicopter; and the principal noise mechanisms affecting each type of aircraft and the opportunities offered by the SRWC configuration to mitigate them. Ongoing work to further clarify important noise mechanisms is also outlined.
Quackenbush, Todd, Ricci-Moretti, Luigi, Brentner, Kenneth, Wachspress, Daniel, Barwey, Dinesh, Lewis, Robert
Fundamental Studies of a Variable-Voltage Hybrid-Electric PowertrainF-0075-2019-146775/13/2019
Advances in electric propulsion may provide the opportunity to incorporate multiple distributed propulsors through the use of electric drives and electric power transmission at dramatically lighter weights than mechanical drivetrains. While small-scale UAS (0-20lb) have achieved distributed electric drivetrains, the electro-chemical power-sources do not scale and are weight prohibitive for larger UAS and future eVTOL aircraft with practical range, endurance, and payload requirements. An alternative to the electro-chemical powertrain is the hybrid-electric powertrain. In this paper, a variable-voltage hybrid-electric powertrain is designed, constructed, and tested carefully to examine the effects of variable-voltage generators for variable-RPM electric drives. The paper examines the powertrain component by component, with over 370 test points, from a single electric drive to an integrated powertrain with four distributed propulsors, in a fully instrumented test bed.
Mills, Brent, Datta, Anubhav
Planetary Power Split Device for Hybrid Vehicle Powertrain2019-01-03704/2/2019
This work looks into the development of power-split planetary gear set for hybrid vehicle. The aim is to research possible solution of hybrid powertrain integrating DHT (Dedicated Hybrid Transmission), which will comply with demands of compact cars, where simplicity and low price is a primary focus. On the other hand, this solution must offer full-hybrid capability. The search of new solution is focused on the usage of one electric motor in combination with internal combustion engine, the planetary gear set (PGS) and stepped transmission. For low forward speeds and reverse the electric drive can be used. The low forward speed can be ensured also by combination of electric motor and ICE, the medium speed range will be covered by powersplit or combination/addition of power of ICE and electric motor, for highway usage the direct drive from ICE via stepped transmission is envisaged. Most of the functional modes allow also the electric energy recuperation. The paper will present the overview of existing solutions; the literature survey will be dedicated for designs with single electric motor mainly. Further will be included the description of newly proposed mechanism, the shift table and full description of all functional modes. For demonstration and simulation purpose was chosen 1.0 L spark ignition engine in combination with 48 V electric motor - the results will be included in the paper. It was decided to build a plastic demonstrator of the newly invented DHT for the functional check.
Kanera, Jaroslav, Achtenova, Gabriela, Kruta, Michal
Pure Electric Vehicles Simulation Using Powertrain Energy Estimator Tool2019-01-03674/2/2019
This paper describes first, the use of Powertrain Energy Estimator (PEE) tool to simulate and analyze the performance of the Pure Electric Vehicles (PEV’s) with all the powertrain components. The PEE uses basic physics calculations and measured components performance with the available vehicle parameters to model and simulate any conceptual PEV. The tool calculates the predicted torques, speeds, voltages, efficiency and power passed from one component to another then saves all the simulation results in a database for further user’s analysis. Secondly, we present a methodology to estimate the maximum power capacity required for PEV driving electric machine (E-Motor). The estimation approach is based on creating a power map, which combines the contour lines for all power levels over vehicle speeds/road climbing grades required for the PEV powertrain driving component (E-Motor) to meet all the vehicle’s performance requirements. The evaluation of the power map uses the vehicle’s specifications and performance requirements. The performance requirements are mainly cover the maximum vehicle speed, acceleration time and road climbing grade. Two types of PEV platform applications are considered in this paper for simulation and analysis: A 10 meters Rear Wheel Drive (RWD) commercial PEV transit bus with two speeds transmission gearbox, the second application is a typical Front Wheel Drive (FWD) OEM PEV passenger car with a single speed transmission gearbox.
Al-Assadi, Salem, McConnell, Jason
Development and Control of Four-Wheel Independent Driving and Modular Steering Electric Vehicles for Improved Maneuverability Limits2019-01-04594/2/2019
Electric vehicles are capable of more flexible drivetrain configurations, such that driving dynamics of each wheel could be controlled independently to increase its stability and maneuverability bounds. We hereby propose a configuration consisting of four wheel independent driving and front and rear axle modular steering. The vehicle implements drive-by-wire technology, which means the control program running on vehicle control computer will have direct control authority of the vehicle under normal driving conditions, based on inputs of higher level systems such as human drivers and autonomous driving programs. Both the torque allocation on four wheels and the steering allocation on axles are completely independent on the mechanical hardware level, thus the vehicle is able to harness adverse contact conditions with confidence. A slip-aware model-free control method for torque allocation and steering is proposed and inspected in the paper, with digital model of a modified SUV simulated for validation, and the vehicle responses with and without such controller are compared to elaborate its strengths. Such control method has more safety margin under close-to-limits driving conditions with presence of tire slip. The control method along with drive-by-wire features also enhance driving safety by correcting excessive inputs by human drivers. Additionally, a comprehensive index reflecting the stability and maneuverability of the vehicle is also introduced and based on which a model-based controller is designed and compared.
Yang, Haoguang, Liu, Chen, Shi, Jiongming, Zheng, Gangtie
Analysis and Model Validation of the Toyota Prius Prime2019-01-03694/2/2019
The Toyota Prius Prime is a new generation of Toyota Prius plug-in hybrid electric vehicle, the electric drive range of which is 25 miles. This version is improved from the previous version by the addition of a one-way clutch between the engine and the planetary gear-set, which enables the generator to add electric propulsive force. The vehicle was analyzed, developed and validated based on test data from Argonne National Laboratory’s Advanced Powertrain Research Facility, where chassis dynamometer set temperature can be controlled in a thermal chamber. First, we analyzed and developed components such as engine, battery, motors, wheels and chassis, including thermal aspects based on test data. By developing models considering thermal aspects, it is possible to simulate the vehicle driving not only in normal temperatures but also in hot, cold, or warmed-up conditions. Next, we analyzed supervisory vehicle control to merge the separately developed vehicle component models in a vehicle simulation model. The supervisory vehicle control includes engine on/off, battery energy management, engine operating conditions, and so on. In particular, we analyzed the control changes according to the warmed-up start and heating, ventilation, and air conditioning operation. We implemented and integrated the analyzed component models in a vehicle simulation model in Autonomie for the Toyota Prius Prime. In most cases, model predictions of fuel economy were within 5% of the experimental value, which is within the range of test-to-test variability. Many of operational signals, including battery state of charge matched well.
Jeong, Jongryeol, Kim, Namdoo, Stutenberg, Kevin, Rousseau, Aymeric
The Differential Braking Steering Control of Special Purpose Flat-Bed Electric Vehicle2019-01-04404/2/2019
Special purpose flat-bed vehicle is commonly utilized to move heavily items such as containers in warehouse, port and other freight handling scene, the hydraulic steering system have be gradually replaced by electric ones. However, the cost of electric steering system is high for commercial activities. Thus, for some corporates, the differential braking steering strategy becomes an ideal alternative. The purpose of this paper is to present a steering control method for flat-bed electric vehicle based on differential braking system. There are two main components of the control method, steering while moving forward and pivot steering, and each of them was composed by upper layer and executive layer. To evaluate the practicability of the control methods, a 7-DOF flat-bed vehicle model was established in Simulink. According to the simulation results at different load, velocity and steering target, the control method proposed in this paper showed quite well performance and meet the basic demand of handling quality while response rapidly to the control target.
Dai, Yaqi, Yu, Liangyao, Song, Jian, Zhao, Wenzong
Model-Based Pitch Control for Distributed Drive Electric Vehicle2019-01-04514/2/2019
On the dual-motor electric vehicle, which is driven by two electric motors mounted on the front and rear axles respectively, longitudinal dynamic control and electro-dynamic braking can be achieved by controlling the torque of front and rear axle motors respectively. Suspension displacement is related to the wheel torque, thus the pitch of vehicle body can be influenced by changing the torque distribution ratio. The pitch of the body has a great influence on the vehicle comfort, which occurs mainly during acceleration and braking progress. Traditionally active suspension is adopted to control the pitch of body. Instead, in this paper an ideal torque distribution strategy is developed to limit the pitch during acceleration and braking progress. This paper first explores the relationship between the torque distribution and the body pitch through the real vehicle test, which reveals the feasibility of the vehicle comfort promotion by optimizing the torque distribution coefficient. A two-degree-of-freedom semi-vehicle model is established according to the actual vehicle parameters. Based on the vehicle model, the control system is established to minimize the pitch motion during the acceleration and braking process by means of a model predictive control technique. The control effect is verified by simulation experiments.
Yu, Yize, Xiong, Lu, Yu, Zhuoping, Yang, Xing, Hou, Yuye, Leng, Bo
Going DIGITAL & ELECTRIC @ bauma 201919TOFHP04_054/1/2019
Digitalization and electrification are dominant themes in the equipment and technology being revealed at this year's largest trade show for construction and mining. Digitalization, efficiency and sustainability are three megatrends that off-highway OEMs and suppliers will be touting this month at the triennial bauma trade fair in Munich, when they reveal their technology-laden machines and the intelligent systems that help make them smarter, cleaner and safer. Particular focal areas for many of these companies include electric mobility, telematics and networked construction sites, and increasingly autonomous operation. Some construction machines are already equipped with a range of sensors and communication interfaces that provide comprehensive data on aspects like job performance, location and fuel consumption. While entire fleets can be managed by telematics, many companies struggle with how to implement digital technologies and services.
Gehm, Ryan
Motor matters19AUTP03_023/1/2019
New designs and materials are key to the next generation of electric machines for EV propulsion. With the momentum to expand vehicle electrification increasing steadily, the industry is beginning to arrange the pieces for its multi-billion-dollar transformation of powertrain development. Ford said it intends to have some 40 electrified models in showrooms by 2022, including 16 all-new battery-electric vehicles. Honda projects electrified vehicles will account for two-thirds of the company's global sales by 2030. General Motors plans 20 electrified models globally by 2023. Even Ferrari is joining the march. As the list grows, it's clear that in a few years, propulsion-system electrification no longer will be news per se. The dialogue will then shift to key differentiators in design, engineering and manufacturing that impact efficiency.
Visnic, Bill, Brooke, Lindsay
Volvo CE, Skanska demonstrate concept electric site19TOFHP02_062/1/2019
Volvo Construction Equipment and Swedish construction and mining company Skanska have recorded impressive initial results from an electric quarry research project. The two companies, working in partnership with the Swedish Energy Agency and two local universities, established an electric site within Skanska's Vikan Kross Quarry, near Gothenburg in Sweden. The concept site has been using a diesel electric hybrid wheeled loader, a cable-electric crawler excavator and crushing equipment, plus eight battery-powered autonomous haulers to quarry and transport blasted rock from the quarry face. In normal operation, the site requires a 70-tonne (77-ton) crawler excavator, a diesel-driven mobile crusher, a 50-tonne (55-ton) wheeled loader and three 50-tonne capacity rigid dump trucks to move around 700 tonnes (770-tons) of blasted rock per hour within the quarry. Between them, these machines consume around 3,000 L (792 gal) of diesel in a working day.
Gilkes, Dan
Q&A19AUTP02_182/1/2019
Which premium vehicle OEM currently offers the broadest range of plug-in vehicles? That would be BMW, with 12 production hybrids and battery EVs including new-for-2019 PHEV variants of the 3-Series sedan and X5. With many more in the pipeline and the company's fifth-generation electric drive system in development for 2020, Automotive Engineering Editor Lindsay Brooke sat down recently with Stefan Jurascheck, BMW VP Development for Electric Powertrains, to discuss details of “the ultimate electrified driving machine.” Jurascheck, an electrical engineer, is a 32-year BMW veteran. BMW's next-gen electric drive architecture is due to launch in 2020. What can you tell us?
FCA'S MICKY BLY amping up electrification19AUTP08_021/1/2019
New powertrain boss Micky Bly and his team are building an advanced propulsion-strategy roadmap that includes at least one more ICE development cycle. With its asphalt-ripping Hellcat and Demon V8s dominating the engine headlines at FCA North America, and boom times for Ram and Jeep sales, hybridization and battery electric vehicles (EVs) have “not been the leading-edge story,” notes Michael “Micky” Bly, the company's newly arrived head of Powertrain Engine Engineering. And, he acknowledged, the company is clearly perceived as trailing the industry in the new-propulsion space. “When I started the interview process to come to this position, that was one of my questions: ‘Where is FCA? Give me some insight,’” he told Automotive Engineering at the company's recent 2020 product preview. “Because what I'm intrigued about is seeing this technology develop-as well as ICE's continuing progress at the same time.”
Visnic, Bill
BorgWarner demos next-step electrification components19AUTP01_111/1/2019
Anyone questioning whether a substantial portion of the light-vehicle market will imminently feature some form of powertrain electrification need look no further than the product portfolios of the major powertrain suppliers. At a recent event at its Propulsion Technical Center in Auburn Hills, Michigan, BorgWarner provided access to a range of demonstration vehicles-from full EVs to hybrid Ford F-150s-featuring technology engineered for OEM's seeking swift electrified integration.
Visnic, Bill, Seredynski, Paul
Cleaning or Etching Items with Unique GeometriesTBMG-335561/1/2019
Cleaning, an integral part of many manufacturing and maintenance processes, is often critical to the performance of a broad range of technologies in the semiconductor, defense, MEMS, photonics and biotech industries.
2018 Create the Future Design Contest: Automotive/Transportation Category WinnerTBMG-3331911/1/2018
Mercedes-Benz getting serious about fuel-cells-for vans18AUTP10_0710/1/2018
Although Mercedes-Benz Vans recently unveiled new battery-electric eVito and eSprinter vans that will be on sale in Europe starting at the end of this year, the company acknowledged that a battery-electric van will not suit all customer operations, particularly where longer range is a factor. To address electric-van range anxiety, it recently showed a concept Sprinter F-Cell. The F-Cell concept uses a compact hydrogen fuel cell, designed to fit in the standard engine bay. The fuel cell stack has 412 cells creating 75 kW. This is passed through an inverter to an underfloor battery pack similar to those used in the new eVito and eSprinter. The 105-kW battery, which can be wall-charged for plug-in use, powers an electric motor, which in turn drives through a transmission integrated into the rear axle of the van, delivering 147 kW (197 hp) and 350 N·m (258 lb·ft).
Gilkes, Dan
Schaeffler debuts new Mover concept at Detroit symposium18AUTP10_1110/1/2018
As part of its 11th Schaeffler Symposium, the Tier 1 supplier debuted a new urban e-mobility vehicle concept called the “Schaeffler Mover.” The symposium, held once every four years, is a forum for Schaeffler to present its technologies and component forecasts to auto-industry professionals and media. The Mover concept is a flexible and emission-free platform engineered for a range of different low-speed vehicle applications. All the drive and chassis components are integrated in one vertical unit called the “Schaeffler Intelligent Corner Module,” which integrates in-wheel motors with discreet steering capability at each corner to save space and enhance maneuverability. Flexibility was a key engineering goal on the Mover.
Seredynski, Paul
Structural Integrity of In-Wheel Motors2018-01-18299/10/2018
In-wheel motors offer an optimized solution for novel drivetrain architectures of future electric vehicles that could penetrate into the mainstream automotive industry, moving the wheel actuation where it’s required, directly inside the wheels. Obtainable literature mainly deals with optimization of electromagnetically active parts, however, mechanical design of electromagnetically passive parts that indirectly influence motor performance also requires detailed analysis and extensive validation. To meet the optimal performance requirements (also durable) of an in-wheel traction motor, their mechanical design requires topology optimization of housing elements, thermal mapping, geometrical and dimensional tolerance checks and selection of proper hub bearings, in order to assure consistent electromagnetic behavior stability The following paper uniquely describes the review of loads acting on an in-wheel motor, the workflow of a typical mechanical design process, testing, and validation processes for achieving the required durability of an in-wheel assembly.
Frajnkovic, Matic, Omerovic, Senad, Rozic, Uros, Kern, Jurij, Connes, Raphael, Rener, Kristof, Biček, Matej
Drive Technology: The Recipe for Precise Actuator ControlTBMG-324668/1/2018
Worldwide, there are only a handful of manufacturers of electrical actuators for the process industry, and the Vienna, Austria-based company Schiebel Antriebstechnik GmbH is the smallest of these. The company's technology is tucked away in the interior of the actuators, ensuring that flows can be regulated in an accurately controlled manner, even in difficult applications. The VLT® Midi Drive FC 280 AC drive from Danfoss Drives is used to ensure actuator quality at Schiebel.
Multi-Attribute, System-Level Design Process for Automotive Powertrain Electric Drives: An Integrated Approach08-07-02-00076/5/2018
This article presents an electric drive powertrain design and virtual integration methodology in the context of electric vehicle systems. In the first stage, using the Model-Based System Engineering paradigm, the electric vehicle performance requirements are translated into electric drive target specifications using a system-level vehicle model. Subsequently, a functional electric drive subsystem-level model is developed based on magnetic co-energy and iron losses data obtained from a reference electric machine design. The functional electric drive model is scaled in order to meet the requested specifications, and it is coupled with different 1D (i.e. lumped-parameter) multi-physics sub-models that are later integrated into the electric vehicle system-level model. At the electric drive level the torque ripple and Noise, Vibration and Harshness characteristics are analyzed. At the vehicle level the energy consumption, thermal behavior, and mechanical performances are determined with reduced computational time. The proposed approach allows for early assessment of multiple attributes and enables designers to make decisions supported by accurate system-level simulations.
Ciceo, Sebastian, Faria, Cassio T., Gyselinck, Johan, Martis, Claudia
Sensor-Free Smart WheelTBMG-290006/1/2018
Technology was developed that not only allows wheels to “know” when and how to rotate, but also enables them to work together in interactive teams. The new technology can be used wherever there is a need for additional support when pulling, pushing, or driving a system that uses wheels. Potential applications range from mobility aids such as wheelchairs, to dollies, wheelbarrows, and shopping carts. Monitoring the data generated when the motors inside the wheels rotate allows the motors and wheels to be controlled without the need for additional sensors.
Design Optimization of the Transmission System for Electric Vehicles Considering the Dynamic Efficiency of the Regenerative Brake2018-01-08194/3/2018
In this paper, gear ratios of a two-speed transmission system are optimized for an electric passenger car. Quasi static system models, including the vehicle model, the motor, the battery, the transmission system, and drive cycles are established in MATLAB/Simulink at first. Specifically, since the regenerative braking capability of the motor is affected by the SoC of battery and motors torque limitation in real time, the dynamical variation of the regenerative brake efficiency is considered in this study. To obtain the optimal gear ratios, iterations are carried out through Nelder-Mead algorithm under constraints in MATLAB/Simulink. During the optimization process, the motor efficiency is observed along with the drive cycle, and the gear shift strategy is determined based on the vehicle velocity and acceleration demand. Simulation results show that the electric motor works in a relative high efficiency range during the whole drive cycle. The energy economy of the case-study vehicle with the optimized a two-speed transmission is also compared to that of the baseline vehicle with fixed-ratio reduction gear.
Zhao, Bolin, Lv, Chen, Hofman, Theo, Steinbuch, Maarten, Zhang, Junzhi, Cao, Dongpu
A Development of Fuel Saving Driving Technique for Parallel HEV2018-01-10064/3/2018
This paper examines the effect of pulse-and-glide (PnG) driving strategies on the fuel efficiency when applied on parallel HEVs. Several PnG strategies are proposed, and these include the electrical, mechanical, and combined PnG strategies. The electrical PnG strategy denotes the hybrid powertrain control tactics in which the battery is charged or discharged according to the power demanded while maintaining the constant vehicle speed. On the other hand, the mechanical PnG strategy denotes the powertrain control tactics in which the vehicle accelerates or decelerates according to the power load while minimizing the battery usage. The combined PnG strategy involves both electrical and mechanical strategies to find a balanced point in between them. Here, a tradeoff relationship between the fuel efficiency and the vehicle drivability related to the tracking performance of the desired target speed is revealed. In the assessment of the feasibility of applying each of the formerly mentioned hybrid driving strategies, the causes of driveline heat loss are recorded and analyzed by their types. These include the engine heat loss, engine friction loss, motor loss, and the resistance loss. The motor loss includes all of the electrical energy loss induced in the powertrain electronics, and the resistance loss includes the loads acting on the vehicle such as the aerodynamic drag and rolling resistance. These factors are quantitatively analyzed for different driving strategies along with the related fuel efficiency in an integrated manner. The experimental validation is conducted using a real HEV equipped with a gasoline spark-ignition engine, transmission-mounted electric drive, and a 6-speed dual clutch transmission.
Eo, Jeong Soo, Kim, Sung Jae, Oh, Jiwon, Chung, Yeon Kwang, Chang, Young Joon
Development of High-Power-Density DC-DC Converter Using Coupled Inductors for Clarity Plug-In Hybrid2018-01-04584/3/2018
Honda has developed an electric powertrain for a 2017 plug-in hybrid vehicle using its second-generation SPORT HYBRID i-MMD powertrain system as a base. The application of the newly developed powertrain system realizes a long all-electric range (AER), allowing operation as an EV for almost all everyday driving scenarios, with dynamic performance making it possible for the vehicle to operate as an EV across the entire speed range, up to a maximum speed of 100 mph. The amount of assist provided by power from the batteries during acceleration has been increased, helping to downsize the engine while also balancing powerful acceleration with quietness achieved by controlling racing of the engine. In order to realize this EV performance with the second-generation SPORT HYBRID i-MMD system as the base, it was necessary to increase the power output of the DC-DC converter, taking restrictions on space into consideration. An interleaved circuit design using coupled inductors was employed as the method of increasing the power density of the DC-DC converter. This circuit design reduced magnetic flux generated in the inductor cores by direct current, making it possible to reduce the size of the inductors. However, it was not possible to position electric devices such as current sensors close to the coupled inductors due to magnetic flux leakage to the exterior, making it challenging to increase the integration density of the components. In order to address this issue, a configuration of coupled inductors that reduces magnetic flux leakage was developed, making it possible to increase the integration density of the peripheral layout of the DC-DC converter. The application of the proposed coupled inductors has increased the continuous power density of the DC-DC converter approximately 2-fold in comparison with the conventional unit employed in previous Honda hybrids.
Komatsuzaki, Akitomo, Hashino, Satoshi
Electrified forklifts go big17TOFHP12_0412/1/2017
Hoist Liftruck brings full electrification to some of the biggest forklift trucks, motivated only in part by regulatory pressures. Early in 2018, Hoist Liftruck Manufacturing will begin delivery of what it terms the “Next Generation of Hoist Electric Vehicles.” These include its TE-Series, PE-Series, Neptune Electric Series and FR-E Series, all battery-electric versions of existing diesel-powered forklift and terminal trucks. While electrified forklift trucks have always been more than a fad, this latest development by the company is interesting because of the mix of motivations. They meet new regulations while growing more cost-effective for higher-end applications. “We are especially excited about rolling out the PE-Series,” said Stu Jacover, Vice President, Strategy and Development for Hoist Liftruck. The P and PE series use pneumatic tires. The heaviest lift in the P-Series lifts up to 125,000 lb (56,700 kg). The heaviest PE-Series battery-electric lift hauls up to 36,000 lb (16,330 kg), often used in port, lumber and oil and gas applications. The PE-Series will meet the Zero Emissions regulations that certain ports have mandated to be phased in by 2020, notably the Ports of Los Angeles and Long Beach.
Morey, Bruce
Integrated Three-Dimensional Module Heat Exchanger for Power Electronics CoolingTBMG-2780311/1/2017
Critical elements in the operation of electric drive systems are power electronics and power semiconductor packages. Improving thermal management of power electronics can help reduce the cost, weight, and volume of electric drive systems, and thus increase market acceptance. The power semiconductor packaging must provide the necessary electrical connections, while at the same time enabling heat removal from the semiconductor devices such as insulated gate bipolar transistors (IGBTs) and diodes.
Experimental Research on Emission Characteristics of Extended-Range Electric Transit Bus2017-01-239410/8/2017
The range-extended electric transit bus (REEbus) equipped with the auxiliary power unit (APU) using high efficient diesel engine as power source can reduce the cost of power battery and is an ideal transitional powertrain architecture to the pure electric drive. Based on chassis tests of a 12m long REEbus, fuel consumption and emission characteristics during Charge-Sustaining (CS) stage effected by temperature of the REEbus are researched. The APU of REEbus starts to work around just one point with best efficiency and lower emission when the state of charge (SOC) is too low and stop when the SOC is high, which aims to lower fuel consumption. As a result, even during CS stage, the fuel consumption of REEbus is only 22.84 L/100km. Also almost all emissions decrease dramatically and the NOx emission is only 0.68g/km, but the ultrafine-particle number increases owing to better combustion. For the engine of REEbus there are colder engine start, severer acceleration and deceleration compared to of the traditional powered buses, so during start for too much fuel injection and acceleration for lacking in inlet fresh air as well as shutdown processes of APU, there are obvious overshoots of the APU speed accompanied with sharp increases of CO, THC emissions, which is more obvious during engine start on colder condition. What’s more, on warm condition the catalyst of SCR lights off much earlier than on cold condition, contributing to significant decrease of NOx emission. So it turns that on warm condition, CO, THC, NOx emissions and the ultrafine-particle mass reduce respectively by 62.6%, 25.3%, 68.1% and 41.0% compared to on cold condition, but the ultrafine-particle number increases by 58.7%.
Xu, Ning, Lou, Di-ming, Liu, Ji-yao, Tan, Piqiang, Hu, Zhiyuan
Volvo CE sees major efficiency gain from hybrid-electric wheel loader17TOFHP10_1210/1/2017
Volvo Construction Equipment partnered with Waste Management (WM), the California Energy Commission and CALSTART to put its LX1 prototype electric hybrid wheel loader to the test: field test, that is. The company showcased the LX1 at a media event in July at WM's Redwood Landfill in Novato, CA. Made up of 98% new parts, the LX1 prototype series hybrid has a fundamentally new machine design. It incorporates a driveline that consists of electric-drive motors mounted at the wheels, electric-driven hydraulics, a battery energy storage system, a significantly smaller diesel engine and new machine architecture including a new design of the lifting unit.
Shuttleworth, Jennifer
Stability Control of Autonomous Vehicles with Four In-Wheel Motor Drive for Severe Environments2017-01-20019/23/2017
Research and development of autonomous functions for a road vehicle become increasingly active in recent years. However, the vehicle driving dynamics performance and safety are the big challenge for the development of autonomous vehicles especially in severe environments. The optimum driving dynamics can only be achieved when the traction torque on all wheels can be influenced and controlled precisely. In this study, we present a novel approach to this problem by designing an advanced torque vectoring controller for an autonomous vehicle with four direct-drive in-wheel motors to generate and control the traction torque and speed quickly and precisely, thus to improve the stability and safety of the autonomous vehicle. A four in-wheel motored autonomous vehicle equipped with Radar and camera is modelled in PanoSim software environment. Vehicle-to-Vehicle (V2V) communication is used in this software platform to avoid collision. Individual in-wheel motor control systems are integrated and networked together using a high-level advanced vectoring control system. The proposed vectoring control system can monitor and manage the behavior of the individual subsystems, assigning appropriate tasks to each of them according to the driving maneuver and road conditions. The performance and effectiveness of the proposed vectoring control system is evaluated using standard test maneuvers. Simulation results show that the proposed advanced torque vectoring controller can improve the vehicle steadiness and transient response properties, thereby enhancing the stability performance compared with the conventional central motor controller particularly for severe environment conditions.
Li, Xin, Situ, Lixin, Yu, Yongqiang, Chen, Feng
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