Browse Topic: Vehicle drive systems

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Using Intelligent Design to Increase Redundancy Without Sacrificing Efficiency Through Adoption of Passive Lubrication in Reduction DrivesF-0079-2023-181515/16/2023
ABSTRACT
Peacey, Robert, Rogers, Lee
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
SAE International Journal of Passenger Vehicle SystemsSAE-JRNL-000154/30/2022
manuscriptUrl https://www.editorialmanager.com/saejpasscarsmech/default.aspx journalImpactFactor undefined
AVSC Best Practice for Metrics and Methods for Assessing Safety Performance of Automated Driving Systems (ADS)AVSC000062021033/25/2021
This AVSC Best Practice for Metrics and Methods for Assessing Safety Performance of Automated Driving Systems (ADS) (AVSC00006202103) recommends a set of metrics that may be used to assess ADS safety performance of the dynamic driving task (DDT). These metrics and methods are principally designed to provide evidence of safety performance for a manufacturer’s decision to deploy (and monitor) fleet-operated/managed SAE level 4 and 5 ADS-dedicated vehicles (ride-hailing or product delivery). This document lays out a performance-based, technology-neutral approach for measuring and analyzing safety performance. It supports long-term, socially-important safety goals (like reducing crashes). ADS safety performance metrics in this document support system-level analyses, i.e. they are practical to implement for any system regardless of architecture. The best practice provides: Metrics to Support ADS Safety Recommended Safety Outcomes Recommended Predictive Safety Metrics Methods for Assessing DDT Performance Metrics The metrics and methods provided in this document are intended for use by the technical community (developers, manufacturers, testers, etc.) to aid in the safe development and deployment of ADS. They may also be useful to stakeholders who have interest in better understanding the safety posture of ADS deployments.
Automated Vehicle Safety Consortium
Definition and Measurement of Power Transfer Unit Speed-Dependent Parasitic LossJ3039_202012 (Current)12/30/2020
This SAE Recommended Practice covers power transfer units (PTUs) used in passenger car and sport utility vehicles to support all wheel drive (AWD) operation. PTUs are typically full-time use geared devices (see 3.1). Some PTUs have additional features such as part-time on-demand capability via electronically actuated disconnect features, and other configurations are possible.
Drivetrain Standards Committee
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
Validation of Telemetry Data Acquisition Using GoPro Cameras2020-01-08754/14/2020
Several GoPro camera models contain Global Positioning System (GPS), accelerometer, and gyroscope instrumentation and are capable of measuring and recording position, velocity, acceleration, and inertial data. This study evaluates the accuracy of data obtained from GoPro cameras through a series of controlled tests. A test vehicle was instrumented with a Racelogic VBOX data acquisition unit as well as various generations of GoPro camera units equipped with GPS capability and driven on a road course. The raw data collected with the GoPro cameras and the translations of this data provided by the GoPro Quik desktop software application were compared to data collected with the validated VBOX data acquisition unit. The results demonstrated that position, velocity, and acceleration data recorded with GoPro cameras is consistent with VBOX data and is useful for applications related to accident reconstruction.
Petroskey, Karla, Funk, Charles, Tibavinsky, Ivan A.
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
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.
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.
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
Heavy Dump TruckTBMG-3567512/1/2019
Mack Defense Allentown, PA 1 (800) 866-1177
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
WHAT WE'RE DRIVING19AUTP10_0710/1/2019
What first impresses about the GT is how easy it is to drive. Ingress is a little tricky over the wide sill, but once situated in the comfy driver's seat you use a strap to position the foot controls to your liking in a very cramped pedal box, and you have a few degrees of seatback angle to play with. The 3.5-L EcoBoost twin-turbo-charged V6 erupts to life from what feels like just behind your right earlobe, but settles quickly in a buzzing idle. Like many competition-focused machines, the V6 has a lightened-crank eagerness about it, but the “automatic” gearbox prevents any uneasiness about getting underway. Thanks to the rear-wheel-drive GT's low and centered mass, the engine can mutter away at low rpm while easily bringing the GT up to traffic speeds.
WHAT WE'RE DRIVING19AUTP09_089/1/2019
As the sporting player in Volvo's C-segment sedan lineup, this all-wheel drive, turbocharged-and-supercharged R-Design S60 faces benchmark competition in the BMW 3-Series, Audi A4 and Mercedes-Benz C-Class. In pure performance, the stylish Swede stacks up nicely against the Germans: Its 316 hp (236 kW) pushes the 3,900 lb (1769 kg) car plus my 200-lb (91 kg) of dead weight from a standstill to 60 mph (97 km/h) in 5.5 s, according to my stopwatch. Dynamically, the S60 T6 (not my choice of nomenclature, as it's a 4-cyl., not a six) feels solid and secure, if not exceptionally nimble, when pushed hard in the corners. But where the S60 R-Design clearly beats the others is inside, the area where Volvo shows its taillamps to the other premium brands. The S60's cabin is a beautifully integrated blend of rich materials and tasteful accents - brushed aluminum of the lower IP contrasting with deep ebony, offset by delightful-to-touch control knobs. The front seats are both handsome and comfortable. Rear-seat legroom is excellent, as my 37-in. (940-mm) inseam can attest.
Holistic hydraulic designs add more sensors, controls19TOFHP08_078/1/2019
Hydraulic system developers are moving on many different fronts as they strive to improve performance and efficiency. A full-system approach that includes more sensors and advanced controls is helping design teams reduce component counts without sacrificing performance. The multifaceted design challenges of today's equipment are forcing engineers to take a broad view of the vehicle and its systems in order to get the most from valves, electronics, pumps and other equipment. Customer expectations and regulatory requirements are both rising, forcing engineers and planners to examine every element of a design.
Costlow, Terry
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
Testing Methods and Signal Processing Strategies for Automatic Transmission Transient Multiplexed Pressure Data2019-01-15006/5/2019
Transmissions have multiple transient events that occur from gear shifting to torque converter clutch application. These transients can be difficult to capture and observe. A six speed front wheeled drive transmission was instrumented with pressure transducers to measure clutches and the torque converter. Due to size restrictions internal to the torque converter the data had to be multiplexed across three different transmitters. A method to capture a transient event through the use of multiplexed data was developed to create a data set with the transient event occurring on each channel. Once testing is completed, the data has to be split into individual channels and synced with the operational data. The data then can be used in both time and frequency domain analysis. It is important to understand that the data is not continuous and must be taken into consideration when post processing it for further results.
Woodland, Mark, Blough, Jason, Robinette, Darrell, Anderson, Carl, Frait, Steve, Devendran, Ram Sudarsan
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
Integrated Multi-Physics Simulation for Full-Vehicle Low Frequency NVH Optimization in HEVs2019-01-14556/5/2019
The recent automotive industry trend towards electrification has created new challenges for NVH engineers. These challenges stem from new powertrain architectures and their complex interactions, the governing control strategies which aim to optimize energy management, and new unmasked sources of excitation. Additionally, vehicle manufacturers are attempting to reduce hardware testing in order to rapidly satisfy increasing production demand and to minimize its costs. Hence, to meet the above-mentioned challenges up front in the development process of Hybrid Electrical Vehicles (HEVs) while balancing competing design objectives of drivability, durability and NVH, a simulation-led design and optimization is required. NVH problems are often the result of mechanisms that originate through complex interactions between different physical domains (flow, electromagnetic, structural/mechanical, control logic, etc.) and the assembly of individual components into a complete system. Therefore, accurate system-level integrated models are becoming a requirement to solve modern NVH problems. Combining the optimal balance between simulation and experimental data, this article describes a joint effort between Ford and Gamma Technologies to develop a general methodology to perform full-vehicle low frequency NVH analysis. Using GT-SUITE software, a non-linear multi-physics simulation model of a rear wheel drive HEV was created. The model was exercised to accurately evaluate the effects of powertrain control strategy and component selection on low-frequency NVH performance during a tip-in regeneration, downshifting and in-gear acceleration maneuvers while minimizing the computational cost.
Gomez, Llorenc Foraste, Zeman, Jonathan, Liu, Jack
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
Parameter Design of a Parallel Hydraulic Hybrid Vehicle Driving System Based on Regenerative Braking Control Strategy2019-01-03684/2/2019
In this paper, hydraulic driving system parameters of a parallel hydraulic hybrid vehicle are designed based on the regenerative braking requirement. Torque, speed and power demands during typical driving cycles are analyzed. The braking control strategy is designed considering both the braking safety and braking energy recovery efficiency. The hydraulic braking torque is determined by the braking control strategy. The proportional relationship of hydraulic pump/ motor output torque and its working pressure is considered. Through simulation with typical city driving cycles, most braking energy can be recovered by the proposed hydraulic driving system and braking control strategy.
Zhou, Shilei, Walker, Paul, Tian, Yang, Zhang, Nong
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 of Innovative Dynamic Torque Vectoring AWD System2019-01-03324/2/2019
This paper describes the development of an innovative AWD system called Dynamic Torque Vectoring AWD for all-wheel drive (AWD) vehicles based on a front-wheel drive configuration. The Dynamic Torque Vectoring AWD system helps to achieve high levels of both dynamic performance and fuel efficiency. Significant fuel economy savings are achieved by using a new compact disconnection mechanism at the transfer and rear units, which prevents any unnecessary rotation of the propeller shaft. In addition, the system is also capable of independently distributing torque to the rear wheels by utilizing electronically controlled couplings on the left and right sides of the rear differential. This greatly enhances both on-road cornering performance and off-road driving performance.
Horie, Ryota, Yuasa, Ryohei
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
Research on Technique for Correction of Running Resistance with Focus on Tire Temperature and Tire Thermal Balance Model2019-01-06234/2/2019
At present, measurements of running resistance are conducted outdoors as a matter of course. Because of this, the ambient temperature at the time of the measurements has a considerable impact on the measurement data. The research discussed in this paper focused on the temperature characteristic of the tires and developed a new correction technique using a special rolling test apparatus. Specifically, using a tire rolling test apparatus that made it possible to vary the ambient temperature, measurements were conducted while varying the levels of factors other than temperature that affect rolling resistance (load, inflation pressure, and speed). Next, a regression analysis was applied to the data for each factor, and coefficients for a relational expression were derived, making it possible to derive a quadratic equation for the tire rolling resistance correction formula. It was verified that the application of the new correction formula reduced variation in running resistance from 2.7% (in the case of regulation correction) to 1.0%. In addition, in order to offer a simpler method of realizing the same correction, a technique for correction using a conventional tire rolling test apparatus and based on the material characteristics of the tire tread rubber was also developed. It was verified that this method allowed the same degree of correction. Giving consideration to the application of the method to future tire modeling, the development of heat generation and dissipation models for tire rolling tests was also examined. The addition of terms for the temperature characteristic of the tread rubber and heat generation and dissipation between the tire and the drum reduced error between measured and predicted values to ±0.6%.
Hotaka, Takeshi, Sakai, Tomonori, Miura, Hideki
An Innovative Electric Motor Cooling System for Hybrid Vehicles - Model and Test2019-01-10764/2/2019
Enhanced electric motor performance in transportation vehicles can improve system reliability and durability over rigorous operating cycles. The design of innovative heat rejection strategies in electric motors can minimize cooling power consumption and associated noise generation while offering configuration flexibility. This study investigates an innovative electric motor cooling strategy through bench top thermal testing on an emulated electric motor. The system design includes passive (e.g., heat pipes) cooling as the primary heat rejection pathway with supplemental conventional cooling using a variable speed coolant pump and radiator fan(s). The integrated thermal structure, “cradle”, transfers heat from the motor shell towards an end plate for heat dissipation to the ambient surroundings or transmission to an external thermal bus to remote heat exchanger. A complete lumped parameter numerical modelling was implemented to estimate the thermal behavior of the corresponding electric motor cooling system. Experimental and numerical results compare the temperature, heat flux, and cooling power measurements. For 250VA thermal load applied, the hybrid heat rejection strategy could save up to 33% of the power consumption while the operating condition is secured. Higher thermal loads can be handled through the combined passive and active pathways with minimum power consumption. Based on these findings, integrated electric motor cooling merits attention for further investigation through field testing, scaling, and utilization in other applications.
Shoai Naini, Shervin, Huang, Junkui (Allen), Miller, Richard, Wagner, John R., Rizzo, Denise, Sebeck, Katherine, Shurin, Scott
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
Nissan concept sport sedan is all-electric, driver-optional19AUTP03_123/1/2019
Nissan looks to pump up the fun factor with the IMs, an all-electric sports sedan concept with autonomous driving capability. The car made its global debut at the 2019 North American International Auto Show. “While still being a driver's car, this concept lives within our very graspable future of creating/engineering a thrilling autonomous ride, bringing the car into the realm of ‘entertainment’, Giovanny Arroba, Nissan's program design director, told Automotive Engineering. IMs features dual electric motors in the front and the rear with an estimated 483 hp (360 kW) and 590 lb·ft (800 N·m) for all wheel drive capability. The 115 kWh battery pack, packaged under the floor, provides an estimated 380-mi (611.5-km) driving range. The sedan's dedicated EV platform essentially mirrors that of Nissan's IMx KURO electric crossover concept that debuted at the Tokyo Motor Show in 2017.
Buchholz, Kami
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?
2020 Ford Explorer: Knockout styling surrounds all-new engineering19AUTP08_201/1/2019
Already America's all-time best-selling SUV, the all-new 2020 Ford Explorer is cast on an entirely new global rear-wheel-drive (RWD) architecture and boasts the first Ford application of its new modular hybrid transmission (MHT). The lighter and stronger architecture underpins the broadest Explorer lineup yet, featuring a new hybrid, an ST model, more powerful EcoBoost powertrains, all-10-speed gearboxes and a host of new safety/convenience tech. With new styling that is razor sharp, consumers would have likely flocked to it regardless. The biggest news for the 2020 Explorer is the new global RWD architecture, with the Explorer being the first application for Ford (Lincoln has already debuted its version with the all-new Aviator). “When you start all-new, the exciting part is you get to work on not only upping the game, but you get to listen to feedback on the prior product, its shortcomings or opportunities,” explained Scott Slimak, the vehicle engineering manager on the new Explorer. “When you're all new, you get to go after all that. You get a chance to wipe the slate clean.”
Seredynski, Paul
Cadillac pulls the wraps off two new V-Series sedans19AUTP08_191/1/2019
Cadillac has added two more sedans to its V-Series performance lineup, the 2020 CT4-V and CT5-V. The CT4-V will square off against established C-segment players such as the BMW 3-Series and Mercedes-Benz C-Class, along with Hyundai's new Genesis G70. The CT5-V will compete with the BMW 5-Series and Audi A6. The two new 4-door sedans join the larger 2019 CT6-V sedan in the V-Series stable, though the company noted that the series is evolving to be less focused on hard-core, track-worthy machines, and more about sporty and comfortable daily drivers. “We are inviting even more customers into the V-Series family,” said Brandon Vivian, Cadillac executive chief engineer, “by adding a new level of elevated performance between our Sport models and the ultimate, high-performance track capability that the V-Series has grown to represent.”
Seredynski, Paul
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