A novel approach on range prediction of a hydrogen fuel cell electric truck C.Venkatesh - Manager - Product Development, Sustainable Mobility & Advanced Technologies Abstract: A novel approach on range prediction of a hydrogen fuel cell electric vehicle Abstract: Today's growing commercial vehicle population creates a demand for fossil fuel surplus requirement and develops highly polluted urban cities in the world. Hence addressing both factors are very much essential. Battery electric vehicles are with limited vehicle range and higher charging time. So it is not suitable for the long-haul application. Hence the hydrogen fuel cell based electric vehicles are the future of the commercial electric vehicle to achieve long range, zero emission and alternate for reducing fossil fuels requirement. The hydrogen fuel-cell electric vehicle range, it means the total distance covered by the vehicle in a single filling of hydrogen into the onboard cylinders.
Automation is expanding in every possible direction and it was only time before it reached the Automobile sector. There has been tremendous traction towards autonomous cars since last 2-3 yrs as a probable solution to reduce accidents and promote safe and comfortable commute. Many companies have expressed their interest in developing some part(s) of it and when would all of this culminate resulting in a fully autonomous car. But as every coin has two aspects so same does automation. This paper covers the future of autonomous cars from Indian perspective, covering possible challenges, complex use cases, advantages, technology enablers, economy outlook etc. India has the dubious honor of ranking first in road deaths in the world at present & accounts for 10 percent of global road accidents with more than 1.46 lakh fatalities annually.
Ride Comfort forms a central design aspect for suspension and is to be considered as primary requirement for vehicle performance in terms of drivability and uptime of passenger. Maintaining a balance between ride comfort and handling poses a major challenge to finalize the suspension specifications. The objective of this project it to perform ride- comfort analysis for heavy commercial truck using MATLAB Simulink. First, bench-marking was carried out on a 4x2 heavy commercial truck and the physical parameters were obtained. Further, a mathematical model is developed using MATLAB Simulink R2015a and acceleration- time data is collected. An experimentation was carried out on the truck at speeds of 20 kmph, 30 kmph, 40 kmph and 50 kmph over a single hump to obtain actual acceleration time domain data. This is followed by running the vehicle on Class A, B & C road profiles-irrespective of vehicle speed- to account for random vibrations.
Tyre Traction Trailer is a device designed to find the Peak Brake co-efficient of C2 and C3 tyre as per ECE R117. The trailer is towed by the truck and is braked suddenly to evaluate braking co-efficient of specimen tyre. It is a single wheel trailer equipped with load cell to capture tire loads (Normal and longitudinal)while braking. Traction Trailer is modelled in MSC Adams and rigid body simulation is carried out for static stability of the system. Dynamic simulations were performed to understand locking of wheels during braking. Body frame was further modelled as flex body to perform structural analysis of the frame. The paper contains stress and deformation plots of trailer Structure under various loading conditions, change in Centre of gravity, weight transfer and forces on springs during braking and cornering, plots of tractive and normal load on tyre during braking.
Increased public pressure to improve commercial truck safety and new stopping distance regulations have intensified the need to better understand the factors influencing heavy vehicle braking performance. To assist individuals and their organizations in preparing for these new truck braking standards, this seminar focuses attendees on understanding medium-duty hydraulic brake systems and heavy-duty air brake systems and how both systems' performance can be predicted, maintained and optimized.
Every automobile has a differential and most have axles, yet the exact function of these is not common knowledge. This comprehensive seminar introduces participants to the function and interfaces of axles and their individual components. As we modify cars for street performance or all out race applications, it is important to know the trade-offs in the drivetrain system. The theory and practice of axle systems is introduced along with a hands-on style approach to repairing and modifying axles for high performance applications. For this hands-on approach, actual hardware will be reviewed in an informal setting.
Vehicle automation and intelligent transportation systems will be the cornerstones of sustainable smart cities of the future. People movers seem to be at the heart of technology development, field trials and on-road testing, and strategic business partnerships when it comes to connectivity and automated driving. Majority of the focus has been on unmanned operation and door-to-door service in urban environments and not on highways. Highways are relatively simpler to handle from an engineering stand-point, but vehicles typically operate at higher speeds, so the cost of accidents is worse.
The inovative approach to the assessment of directional stability of two-axle wheeled tractors during braking is considered. Assessment of the feasibility to in-stall brake mechanisms only on one axle of the tractor are considered. The equations to determine rational choice of braking force distribution between the axles for two-axle wheeled tractor are obtained. The coefficients of braking forces distribution between the axles of two-axles wheeled tractors of classical construction are obtained. The influence of the braking forces distribution between the axles on stability of wheeled tractors are determined. It was determined that operation of the brake systems of wheeled tractors has a significant impact on their directional stability, which is also manifested by the lack of a tendency to skid during braking. There is proposed improved method for evaluating the impacts of braking system on wheeled tractors stability by using the method of partial accelerations.
The tractor-trailer dynamics during braking and the effect of the dynamic distribution of normal vertical reactions between the axles on the brake properties of tractor-trailer is considered. A mathematical model of the process of braking the tractor-trailer (consisting of a wheel tractor and a two-axle trailer), without blocking the wheels was obtained. The conditions for simultaneously bringing to the verge of blocking the wheels of the tractor, trailer and tractor-trailer, as a whole, are determined. Using mathematical modelling methods, method of determine braking conditions of a tractor-trailer without blocking the wheels and the danger of folding is proposed. Obtained analytical expressions, allowing to determine the total normal reactions on the axes of the tractor-trailer and reactions in the connecting hinge of the links between the tractor and the trailer.
The cause of a large number of traffic accidents is an instability of frictional pairs characteristic of the braking system. The car went from the factory`s conveyor has a brake pads which were quality selected. The owner buys a brake pads of various firms in the process of exploitation. It is not pass by it`s characteristic of the thermal stability to frictional pairs of the back axle. It was identified a significant deviation of braking force allocation between axles in the process of traffic and stand experiments with the car with different combination of frictional pairs characteristic which were setting on the front and back of the brake`s system. The reduction of the braking force`s distribution`s coefficient on the front axle that were identified with experiments can become a cause of braking wear. It is necessity for cars and road trains to ensure not only high marks of the brake characteristics but uniform distribution braking force on the axles.
The brake pedal is the brake system component that the driver fundamentally has contact and through its action wait the response of whole system. Each OEM define during vehicle conceptualization the behavior of brake pedal that characterizes the pedal feel that in general reflects not only the characteristic from that vehicle but also from the entire brand. Technically the term known as Pedal Feel means the relation between the force applied on the pedal, the pedal travel and the deceleration achieved by the vehicle. Such relation curves are also analyzed in conjunction with objective analysis sheets where the vehicle brake behavior is analyzed in test track considering different deceleration conditions, force and pedal travel. On technical literature is possible to find some data and studies considering the hydraulic brakes behavior.
Analysis of road accident has showed that an important portion of fatal crashes involving commercial vehicles is caused by rollovers. ESC systems in commercial vehicles can reduce rollovers, severe understeer or oversteer conditions and minimize occurences of jackknifing conditions. Several studies have estimated that this positive effect of ESC on road safety is substantial. In Europe, Electronic Stability Control (ESC) is expected to prevent by far the most fatalities and injuries: about 3,000 fatalities (-14%), and about 50,000 injuries (-6%) per year. In Europe, Electronic Stability Control Systems is mandatory for all vehicles (since Nov 1st, 2011 for new types of vehicle and Nov 1st 2014 for all new vehicles), including commercial vehicles, trucks and trailers.
The stability of the vehicle when braking is one of the most important operational properties that determine traffic safety. This article proposes a probabilistic method for estimating the sustainability of multi-axle vehicles based on the model of normal distribution of the stability coefficient values. The solution to the problem of stability of a multi-axle vehicle during braking is connected with the determination of the dynamic distribution of normal road reactions between the axles. To assess the stability of the vehicle is used as an indicator of the stability factor representing the ratio of the stabilizing moment to moment, the perturbing skid. When the values of the stability coefficient is greater than or equal to unity, the movement is stable, and otherwise it is unstable. For a multi-axle vehicle, determining the dynamic normal road reactions on the axles is possible after disclosing the static uncertainty of the physical model of the car, which is a multi-support beam.
Automotive brakes operate under varying conditions of speed and deceleration. In other words, the friction material is subjected to a wide range of normal loads and sliding speeds. One widely accepted test procedure to evaluate, compare and screen friction materials is the SAE J2522 Brake Effectiveness test, which requires full-size production brakes to be tested on an inertia brake dynamometer. For the current investigation, disc pads of two types of 10 different formulations (5 high-copper and 5 copper-free formulations) were prepared for testing on a front disc brake suitable for a pickup truck of GVW 3,200 kg. Each pad had 2 vertical slots, and one chamfer on the leading edge and also on the trailing edge of the pad. One segment of the test procedure looks at the coefficient of friction (Mu) under different brake line pressures and different sliding speeds to determine its stability or variability.
Heavy truck brake blocks are found to swell (or expand) permanently during testing or usage, especially so at high temperatures, thus leading to longer durability as measured by thickness loss, similar to light vehicle disc pads. This swelling phenomenon occurs continuously in the layer adjacent to the friction surface during testing or usage; not a one time event. The thickness loss estimated from the weight loss is always greater than measured thickness loss. Brake block wear does not increase linearly with increasing normal load, and the load-sensitivity of block wear is very much dependent on the products. A new test procedure has been developed for generating friction-vs.-temperature and wear-vs.-temperature data at a constant temperature employing intermittent braking on the Chase Brake Lining Quality Tester (SAE J661) and friction material wear can be compared on equivalent-work basis.
When driving in mountainous areas, vehicles often encounter downhill conditions. To ensure safe driving, it is necessary to control the speed of vehicles. For internal combustion engine vehicles, auxiliary brake such as engine brake can be used to alleviate the thermal load caused by the continuous braking of the friction brake. For battery electric vehicles (BEVs), regenerative braking can be used as auxiliary braking to improve brake safety. And through regenerative braking, energy can be partly converted into electrical energy and stored in accumulators (such as power batteries and supercapacitors), thus extending the mileage. However, the driver's line of sight in the mountains is limited, resulting in a certain degree of blindness in driving, so it is impossible to fully guarantee the safety and energy saving of downhill driving.