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Technical Paper

Research on Locked Wheel Protection Function of Aircraft Brake System

2021-10-11
2021-01-1269
Locked wheel protection is an important part of antiskid control for aircraft brake control system. Locked wheel protection compares the wheel speed of two or more wheels, if one of the wheels is too slow, locked wheel protection releases the brake pressure on the slow wheel. This work aims to study the control logic for locked wheel protection. Locked wheel protection control logic consists of 3 key factors: paired wheels, active threshold and inhibit velocity. Focus on comparison different options of these 3 factors, all aspects of control logic for locked wheel protection had been expounded in this study. Simulation and calculation analysis is applied for different locked wheel strategies to evaluate the effect. One conclusion is that the greatest wheel speed of the wheel under control shall be set as a reference speed for locked wheel protection. This study provide the basis to design a proper locked wheel protection function of aircraft brake control system.
Technical Paper

Systems of Automatic Brake Torque Reduction on the Wheels of One Axle of the Car

2021-10-11
2021-01-1266
Braking mechanisms have the most variation in performance of all of the elements of the braking system. Instability of braking torques on the wheels of one axle of the vehicle leads to the appearance of the braking forces unevenness, and then- to the vehicle skidding during braking. At one time, the appearance of open-type disc brakes made it possible to reduce the unevenness of the braking forces on the sides of the car due to their higher characteristics of energy intensity and stability. However, the lack of feedback between the left and right disc brakes mounted on the same axle of the vehicle does not allow reducing the unevenness of the braking forces to an acceptable minimum. The authors of the work studied and proposed several systems for automatic reduction of the braking torques unevenness for braking mechanisms mounted on the wheels of one axle.
Technical Paper

Research on Braking Energy Recovery Strategy of Pure Electric Vehicle

2021-10-11
2021-01-1264
With the increasingly serious global environmental and energy problems, as well as the increasing number of vehicles, pure electric vehicles with its advantages of environmental protection, low noise and renewable energy, become an effective way to alleviate environmental pollution and energy crisis. Due to the current pure electric vehicle power battery technology is not perfect, the range of pure electric vehicle has a great limit. Through the braking energy recovery, the energy can be reused, the energy utilization rate can be improved, and the battery life of pure electric vehicles can be improved. In this paper, a pure electric vehicle is taken as the analysis object, and the whole vehicle analysis model is built. Through the comparative analysis, based on the driver's braking intention and vehicle running state, the braking energy recovery control strategy of double fuzzy control is proposed.
Technical Paper

Potential and Challenges for Application-Specific Friction Characteristics of Race Brake Pads

2021-10-11
2021-01-1282
As a race driver hits the pedal to trigger the braking event, a dynamic load transfer takes place in the car. This is a similar kind of weight transfer experienced on the road while stopping any vehicle abruptly. Modern race cars such as FIA-regulated Grand Touring Car classes GT3 and LMGTE produce a significant aerodynamic downforce at a reasonably high efficiency level. In this type of high downforce race cars, load variations originated by aerodynamics are added onto the mass transfer. The combination of these effects provide a braking effect with this type of cars a highly transient character. At the same time, our customers are facing the challenge of strict technical regulations, usually forbidding brake control systems. In motorsport competition, car performance is of primary priority to help our customers win championships.
Technical Paper

Analysis of the Effect of the Wedged Type Brake Caliper Piston on Brake Drag

2021-10-11
2021-01-1293
Recently, there’s a massive flow of change in the automotive industry with the coming era of electric vehicles and self-driving (autonomous) vehicles. The automotive braking system field is not an exception for the change and there are not only lots of new systems being developed but also demands for researches for optimizations of conventional brake systems fitting to the newly appeared systems such as E-Booster and Electric Motor Brake (EMB) Caliper. Taking the Electric Motor Brake Caliper for example, it is considered as a very important and useful system for autonomous vehicles because the motor actuator of the caliper is much easier to control with ECUs compared to the conventional hydraulic pressure system. However, easy of control is not the only thing that excites brake system engineers.
Technical Paper

Measurement of Particle Dynamics on the Real Vehicle in Different Driving Scenarios with Swarm Sensors

2021-10-11
2021-01-1299
Due to the increase in public attention in the analysis of non-exhaust emission sources because of the growing electrification of vehicles, measurements have been performed in recent years to develop a consistent test standard. In particular, the consideration of tyre and brake abrasion took a predominant position due to the small particle sizes. With measurements under controlled and laboratory-like athmosphere, for example for brakes on dynamometers, attempts have been made to create a uniform test standard according to the Worldwide harmonized Light vehicles Test Procedure (WLTP). However, a transfer to the real driving environment is not yet feasible because of many external disturbance variables, such as the wheel housing or atmospheric variables. Typical reference measurement sensors in the vehicle are only suitable to a limited extent for mobile operation due to their size and the necessary measurement infrastructure.
Technical Paper

Investigations on the Deposition Behaviour of Brake Wear Particles on the Wheel Surface

2021-10-11
2021-01-1301
The deposition behavior of brake wear particles on the surface of a wheel and the mechanisms on it have not been fully understood. In addition, the proportion of brake wear particles deposited on the wheel surface compared to the total emitted particles is almost unknown. This information is necessary to evaluate the number- and mass-related emission factors measured on the inertia dynamometer and to compare them with on-road and vehicle-related emission behaviour. The aim of this study is to clarify the deposition behavior of brake particles on the wheel surface. First, the real deposition behaviour is determined in on-road tests. For particle sampling, collection pads are adapted at different positions of a front and rear axle wheel. In addition to a Real Driving Emissions (RDE)-compliant test cycle, tests are performed in urban, rural and motorway sections to evaluate speed-dependent influences.
Technical Paper

The Impact of Wheel Rotations to the Lateral Runout of a Hybrid Material or Dimensionally Reduced Wheel Bearing Flange

2021-10-11
2021-01-1298
The automotive industry is continuously striving for lower mass components including wheel bearings. A typical wheel bearing is mostly steel, including both the wheel and knuckle mounting flanges. Mass optimizations through cross section reductions and/or the use of alternative materials is now part of component development. While bearing component performance is varied thru analysis and testing by the supplier, Vehicle integration impacts over time also need to be comprehended. In a recent new vehicle architecture, the wheel bearing flange was optimized for low mass. The wheel mount flange thickness was reduced, and holes were added for further optimization. While the design met all the supplier and OEM’s component level specifications, vehicle testing revealed that the wheel bearing developed high assembled lateral runout (ALRO) when the wheels were rotated multiple times during a durability schedule.
Technical Paper

Battery Heat Load Estimation and Modeling its Thermal Management Using Air Conditioning Cooling System of an Electric Vehicle

2021-10-01
2021-28-0231
The performance of lithium-ion batteries and its service life depends on its operating temperature. Operating the battery above 45 °C degrades the performance of the battery and reduces its service life. The high-temperature operation also leads to thermal runaway. So there is a need to monitor the operating temperature and voltage output of the battery using a battery thermal management system to ensure its safety. Battery Thermal Management System (BTMS) is a part of the battery management system. The effectiveness of the battery thermal management system depends on the battery pack design, battery chemistry, vehicle operating characteristics and ambient conditions. In this work, a refrigerant-based BTMS is modeled using MATLAB Simulink. Refrigerant R134a used in the air conditioning system of an Electric Vehicle is used as an evaporative cooling medium to cool the batteries.
Technical Paper

A Case Study on Effect of Subsequent Operations on Shot Peened Crown Wheel Pinion (Hypoid Gear Set) & Compressive Residual Stress Analysis

2021-09-22
2021-26-0252
The prime function of crown wheel pinion is to receive the power from transmission & distribute to two-wheel ends. Doing so these members will experience the tremendous bending fatigue. Shot peen is the one of the latest technology used to improve the bending fatigue of the CWP [1]. In this particular case- six CWP are taken for the study to understand the effect of the operations after shot peen process. Three Samples are named as batch A, another 3 samples are named as batch B. Both the batch CWP are shot peened. Then as a regular production practice the batch A CWP are process through hard turning ➔ Abrasive lapping ➔ Hot lubriting (manganese phosphate) ➔ Fully finish ready for assembly. Then both the batch A & batch B samples are taken for residual stress analysis using X-Ray diffraction technique. The measurement location is 50 microns below the surface. The results tabulated, found that batch A samples shows decrease in Residual stress relatively to batch B.
Technical Paper

A Detail Study of Axle Shaft Stress State Change due to Vertical Bending Load in a Commercial Vehicle Axle

2021-09-22
2021-26-0328
Heavy commercial vehicle axle shafts are designed for torsion load. Typically, axle shaft fracture mode during the test is torsional in nature through either shaft body diameter or spline end. However, some of the field return axles shows fracture mode on axle shaft flange. This fracture mode does not resemble with a typical lab test torsional fracture. Metallurgical investigation report indicated that the fracture mode is bending in nature. This paper thus focuses on detail study of change in boundary condition and load transfer path under abusive vertical bending load on axle. A detail finite element analysis is performed to understand stress state change in axle shaft under this condition. A fracture hypothesis is proposed based on observations of finite element analysis results. A detail case study is presented depicting correlation of proposed hypothesis with physical fracture mode.
Technical Paper

Failure of Li-Ion 18650 Cylindrical Cells Subjected to Mechanical Loading and Computational Model Development

2021-09-22
2021-26-0318
To enhance the crashworthiness of electric vehicles, designing the optimized and safer battery pack is very essential. The deformed battery cell can result in catastrophic events like thermal runaway and thus it becomes crucial to study the mechanical response of battery cell. The goal of the research is to experimentally investigate the effect of mechanical deformation on Lithium-ion battery cell. The paper thoroughly studies the phenomenon of short circuiting at the time of failure. Various experiments are carried on 18650 cylindrical cells (NCA chemistry) under custom designed fume hood. The setup captures the failure modes of battery cell. The loading conditions have been designed considering the very possible physical conditions during crash event. The study has been done for radial compression, semicircular indentation, hemispherical indentation, flat circular indentation and case of three-point bending.
Technical Paper

FEA Based Approach for Heavy Duty Commercial Vehicles Lift Axle Weld Analysis and Physically Correlated

2021-09-22
2021-26-0316
Highway transportation using truck is an important transport mode of goods and product to their destination. Commercial vehicle is expensive mode of transportation so it will be protected from failure. For Heavy duty truck they are fully loaded at one side of transportation and other side empty transportation. In such case lift axle grounded when truck is loaded and when truck is empty it is in lift condition. Lift axle is play important role while loading so it is important that it should not fail. Many times lift axle fails at weld location due several load come on the axle. In this paper study of weld failure to vertical, braking and lateral load come on lift axle when truck is in loading condition. Weld failure check in CAE analysis with various load cases and compare with actual physical vehicle failure. Weld failure correlation well correlate when actual loading are consider in analysis. For analysis loading data is measure from RLDA data that will be used for analysis.
Technical Paper

Thermal Management of the Li-Ion Battery Pack with Phase Change Material (PCM)

2021-09-22
2021-26-0140
In electric vehicles, Li-ion battery pack is the most expensive subsystem. Therefore, extending the life of the battery pack and thereby reducing the need for battery pack replacement is necessary to offer a viable product at a competitive cost of ownership. Thermal management of battery pack plays an important role in achieving the above mentioned objective since the performance and life of lithium ion batteries is greatly influenced by temperature. There are various thermal management strategies available to keep the temperature under control like air cooling, chilled liquid cooling and hybrid cooling systems. In this paper, a comparison between phase change material (PCM) and PCM/liquid hybrid cooling is made. The result of the study to understand the applicability of PCM for thermal management of Li-ion batteries is presented. CFD thermal analysis under constant electrical load of 1C rate is carried out.
Technical Paper

Optimized Cooling System Concept for Electric Compact-SUV with Indian Environmental Conditions

2021-09-22
2021-26-0410
With the rising pollutant emission level in Indian cities, the focus on pure BEVs is also increasing in India. Therefore, the Indian Government is currently preparing suitable policies to promote the acceptance of BEVs (e.g., FAME-2) [1]. The goal is to provide subsidies and develop the required infrastructure for battery charging. The environmental conditions in India differ significantly from those in other developed countries in Europe or China. The maximum temperatures can rise to 55 °C in the summertime [2]. In winter, temperatures in the northern Himalayan regions can fall below -25 °C [3]. Within this wide range of environmental conditions, all components, such as the electric motor and battery, must be conditioned by the thermal system of the vehicle. On the one hand, HV battery packs are one of the main cost drivers. On the other hand, currently, the battery size must be maximized to improve the driving range and ensure customer acceptance.
Technical Paper

Smart and Compact Simulation Tool for Electric Vehicle Component Sizing

2021-09-22
2021-26-0419
Electric Vehicles (EVs), with its inherent advantage of zero tailpipe emissions, are gaining importance because of aggressive push from government not only to reduce air pollution but also to reduce dependency of fossil fuel. EVs and necessary charging infrastructure along with ‘connected’ technology is redefining mobility. Considering the fast growing EV market, it becomes important for an EV Powertrain Architect to design and develop a powertrain solution having low engineering efforts and satisfying business, market and regulatory requirements at a competitive price. This paper presents a compact, flexible, convenient and smart featured simulation tool for an EV Powertrain Architect for estimating the specifications of key powertrain components such as traction battery and electric motor. The proposed tool takes into consideration the end-user as well as the regulatory requirements of range, maximum speed, acceleration and gradeability.
Technical Paper

Bogie Wear Pad - A Comparative Study

2021-09-22
2021-26-0442
Bogie-type suspensions for trucks are comprised of two axles and a central spring pack on each side of the truck chassis. Bogie suspensions have a good load distribution between the axles and are used for severe applications in trucks, in off-road conditions thereby subjecting them to extreme stain and load. In today’s competitive market scenario, it of utmost importance to minimize down time in commercial vehicles as it directly corresponds to loss in business which leads to customer dissatisfaction. It is therefore essential to optimize and select the right material for each component in the bogie suspension system. This paper deals with the material selection and testing of one such component - Bogie Wear Pad. The bogie wear pad undergoes sliding friction throughout its lifetime during loading and unloading of bogie suspension. Three different materials are selected and their wear is measured under the same conditions of loading.
Technical Paper

Modeling and Simulation of Lift Axle Control System at Vehicle Level Using AMESim

2021-09-22
2021-26-0427
Lift axle is essentially provided in commercial vehicles to increase the vehicle’s load-carrying capacity. The axle is lowered in the case of a high payload and the load is evenly distributed among the wheels both on fixed axles and the lift axle. This ability to lift the axle implies better maneuverability in turns, better fuel consumption, and less wear and tear on the tires and brake shoes. Also, it will reduce the damage to the road surfaces. This lowering and lifting of the lift axle are controlled by a series of valves together called the Lift Axle Control System (LACS). This LACS must consider the vehicle load condition, the ignition state, and gear state to decide if the axle must be lifted or lowered. This paper deals with the modeling and simulation of the LACS system at the vehicle level and optimize the design for the respective desired design solution.
Technical Paper

Hybrid-Powertrain Development Approach to Reduce Number of Prototype Vehicles by Taking Right Decision in Early Development Phases on Engine Testbeds

2021-09-22
2021-26-0449
Today’s automotive industry is changing rapidly towards environmentally friendly vehicle propulsion systems. All over the globe, legislative CO2 consumption targets are under discussion and partly already in force. Hybrid powertrain configurations are capable to lower fuel consumption and limit pollutant emissions compared to pure IC-Engine driven powertrains. Depending on boundary conditions a numerous of different hybrid topologies- and its control strategies are thinkable. Typical approach is to find the optimum hybrid layout and strategy, by performing certain technical design tasks in office simulation directly followed by vehicle prototype tests on the chassis dyno and road. This leads to a high number of prototype vehicles, overload on chassis dynos, time consuming road test and finally to tremendous costs. Our developed approach is using the engine testbed with simulation capabilities as bridging element between office and vehicle development environment.
Technical Paper

Evaluation of Cable Harness of an Electric Vehicle Powertrain through Simulation

2021-09-22
2021-26-0350
The Electric Vehicles (EV) or Hybrid Electric Vehicle (HEV) has a bunch of electrical/electronic components and its operation give rise to complicated EMI/EMC issues. The Power Electronics Module (PEM), comprising of DC-DC convertor/invertor and Battery Management Unit (BMU), is driving the motor to propel the vehicle. “Battery Pack Module” powers these units through cables. The fast switching of these circuit elements present in the system leads to noise propagation through the cables. These noise signals give rise to various Electromagnetic (EM) related issues in the cable harness of vehicle. It is essential that these cables should not interfere with other electronic components and also does not get effected by external EM disturbances.
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