Piston Failue

　

Heavy Duty Technology: Piston Failure Analysis
By Dennis Nail
While there are many "cut and dried" reasons for aluminum piston failures, the majority can be attributed to a combination of various conditions. The air/fuel, coolant and oil systems and relationships between various engine operations and the cylinder liner temperatures are critical to maintaining proper operation of all cylinder components.
A variety of conditions can cause excessive piston growth or melting, and each will cause varying results – including catastrophic engine failure.
The correct air/fuel ratio balance of an engine is most critical for piston longevity, durability and proper engine operation. The combination of too much fuel or too little air will have the same result – thermal growth or piston crown erosion. This can be attributed to clogged air intakes, restricted exhaust, malfunctioning turbo, incorrect fuel pump calibration, injector contamination, and of course, injection or engine timing.
Heavy-duty diesel pistons are designed to give long service life with the proper air/fuel ratio balance. Any of these attributes will shorten piston life or cause catastrophic engine failure.
Coolant temperatures are another major area of concern. However, this is not always a blatant case of running out of engine coolant. Low coolant levels, old coolant, lack of maintenance such as plugged radiators, air in the system and restricted air flow, or a combination of the above factors can cause excessive piston growth resulting in ring scuffing, skirt or crown scuffing and ultimately piston seizure.
The piston cooling jets help to control piston crown temperatures. The most common conditions of inoperative piston cooling spray jets are misalignment and restricted oil passages. It is very important to remove the piston spray jets prior to cylinder component removal and installation. Metal jets are easily misaligned or fractured from contact by the cylinder component assembly, while plastic jets can be cracked or broken.
Once the cylinder components are installed, the piston spray jets can be checked for proper alignment and operation. Failure to follow this procedure will result in higher piston crown temperatures, which will migrate down to the piston skirt area. The increase in piston skirt temperature will expand the diameter above the allowable tolerance and eliminate the piston-to-liner clearances, resulting in piston seizure.
Engine operation
Severe lugging or lower engine revolutions cause a decrease in fresh air volume, resulting in piston crown overheating. Excessively high engine revolutions, described as "over-speeding" can stretch the component tolerance "stack-up," causing the pistons to contact the valves, which can cause piston or valve damage. Material displaces from the piston crown due to the valve impact, and wedges in between the piston skirt and liner wall. This creates an adhesion condition, which leads to piston seizure.
Piston Failure Analysis Identification
Piston Crown Scuffing
Probable Causes
Piston Crown Burning
Probable Causes
Quarter Point Skirt Scuffing
Probable Causes
Center Point Skirt Scuffing
Probable Cause
Piston Ring Scuffing
Probable Causes
Piston Crown Cooling
Severe Piston Crown Temps
Probable Causes
Assembly Errors
Probable Causes
When piston failure has occurred, it is extremely important to thoroughly inspect all of the engine components during the disassembly procedure. This thorough inspection will lead you to the possible cause or causes of the piston failure and will ensure that the same piston failure doesn’t occur once the engine is repaired and placed back into service by your customer.
Shehjad Ali is technical support managerPiston ring end gap misalignment
Expander end gap is same as oil ring end gap.Assembly errors can and will contribute to high base pressure and can cause oil to bypass the rings. This can create a build-up of abrasive carbon, which can lead to ring scuffing, a loss of ring control, and possible piston seizure.Over-fueling
Fresh air intake restriction
Exhaust restrictionThe burnt oil shown in the example on page 63 clearly indicates that the piston crown was overheating. The burnt oil creates a thermal barrier, and does not allow the fresh-cooled oil to pull any heat from the piston crown, compounding an already existing condition.These indications determine if the piston cooling was a contributor or the possible cause of a piston failure. The two pictures at the right show this. On the top is an example of insufficient crown cooling. The example on the bottom shows proper crown cooling. Fuel wash-down
Debris ingestion
Severe overloadingRing scuffing leads to ring face wear, which results in ring face damage and a loss of ring control. This causes high base pressure, oil consumption and possible piston scoring, due to the abrasive materials created by the ring scuffing condition. This can cause piston seizure if not addressed.Cold engine start at high loads or rpm.Piston skirts are not round, but elliptical, until the engine reaches operating temperature. When a cold engine is started and is operated at high loads or rpm, center point skirt scuffing may occur.Overheating of coolant system
Lack of heat transfer in cylinder
Lack of piston crown coolingThe piston skirt is the gauged bearing clearance area, and it is important to maintain minimum piston skirt temperatures. If excessive heat is allowed to migrate down to the skirt area, thermal expansion will eliminate the piston-to-liner clearance, and will cause skirt scuffing.Improper injection timing
Injector contamination
Nozzle failure
Lack of fresh air supply
Exhaust restriction
Excessive use of etherPiston crown erosion is commonly known as "Piston Burning" and is normally a result of an improper air/fuel ratio balance.Over-fueling of specific cylinder
Lack of fresh air to that cylinder
Exhaust restriction
Engine or injection timing
Lack of piston crown coolingCrown scuffing occurs when the piston rapidly exceeds normal operating temperatures. Typically, this is caused by an over-fueling condition, a result of either too much fuel or too little air. In some applications, a lack of oil cooling the crown can also cause rapid piston crown growth, resulting in a loss of crown-to-cylinder liner clearance, creating crown scuffing and possible seizure. at excessive loads, described as "severe lugging" or running the engine above the rated speed recommended by the manufacturer’s specifications, can also lead to cylinder component damage. Greater loads equate to higher engine component temperatures.

Hybrid Technolgy

The Beijing Olympics saw a total of 80 hybrid and alternative fuel vehicles on public demonstration as ordinary taxis and transport for Olympic officials last year. After the Games the cars were quickly whisked back to their respective manufacturers and stripped down for evaluation. The Olympic hybrid car program had been the first stage in a far-reaching plan to gradually introduce China’s people to the concept of energy-saving and more environmentally friendly vehicles. The vehicles taking part had performed their onerous ferrying duties without fault, enabling the manufacturers to go on to the next stage in the process. Late in 2008, one of China’s newest car manufacturers, BYD of Shenzhen, announced the world’s first production plug-in hybrid car. A series of announcements by China’s other domestic car manufacturers surrounded this astonishing news. Brilliance announced its medium-powered hybrid at the Guangzhou fair in November and Chery put two models – one a hybrid and the other a fully electric car – onto the market early in the new year. The local press was full of environmental claims, but some of the prices were almost double those of conventional models. February 2009 saw the annual Chinese People’s Political Consultative Conference in Beijing, at which the Ministry of Finance publicly announced the provision of 10 billion yuan (around U.S. $1.4 billion) of extremely generous subsidies for purchasers of hybrid and alternative energy ("new energy" as they are known in China) vehicles. China’s new large-scale public demonstration and trial funded by the Ministry of Finance will take place in 13 large urban areas, including Beijing and Shanghai. Each local area is to purchase new hybrid and alternative energy vehicles, comprising government transport, public service (postal service and sanitation, for example) and public transport vehicles. The vast majority will be passenger cars and light commercial vehicles, and they will include mild, medium, and full hybrids, range extender hybrids, alternative fuel, and fully electric. Enormous subsidies are also on hand to support the purchase of heavy duty fuel cell buses. "We are investing a lot of money to ensure that each urbanized area takes at least 1000 vehicles, and if the program succeeds, it will help to raise private buyers’ awareness and acceptance of these new technologies and expand their coverage," a Ministry of Finance official who was unwilling to be named told AEI. The program will run for three years and the funds will come from various sources, including the state, local government, and local public transport authorities. The official said the funds will not be available up front for purchase of these vehicles. Instead, the money "will be refunded for each purchase upon production of the relevant vehicle purchase documents." Details of the subsidies: Trial regionsBeijing, Changchun, Changsha, Chongqing, Dalian, Hangzhou, Hefei, Jinan, Kunming, Nanchang, Shanghai, Shenzhen, and Wuhan Vehicle typeChinese yuanU.S.$Note Passenger car and light commercial vehicle subsidies HybridUp to 50,000$7315divided into five levels, depending on economy Pure electric60,000$8780 Fuel cell250,000$36,580 Hybrid fuel economymin. 5% improvement for light commercial vehicles, min. 10% improvement for passenger cars Subsidies for buses over 30 ft (9.1 m) long Hybrid80,000 - 420,000$11,700 - $61,450depends on battery chemistry (lead-acid, NiMH, or lithium) Pure electric500,000$73,150 Fuel cell600,000$87,790 The new subsidies will provide a healthy stimulus to ensure that high technology R&D on hybrid and new energy vehicle continues around the country – by universities, suppliers, and manufacturers themselves. One form of motive power that was conspicuous by its absence was the diesel engine. China faces a relative shortage of this fuel as a result of its relatively high production cost and competition for diesel and other heavy fuel oil by other industries in China. AEI Details of current hybrid and alternative energy vehicles in China: BrillianceThe BS6　"Zunchi" medium hybrid sedan uses a locally developed turbocharged 1.8-L gasoline engine. The electric traction motor is rated at 10 kW and uses an NiMH battery pack, which, along with the vehicle controller, is produced in the Shanghai region. The powertrain performs start-stop, regenerative braking, and boost functions, with a claimed improvement in economy of up to 35% against similar-sized sedans. Brilliance, which assembles BMW 3- and 5-Series sedans in partnership in Shenyang, has equipped the car with a manual gearbox. Negotiations to supply a limited number of vehicles to urban areas are ongoing. The company also has plans to introduce a mild hybrid vehicle in the near future, possibly based on its new FRV hatchback model. BYDShenzhen-based BYD’s F3 DM plug-in hybrid is a "range extender."It uses an electric motor for traction, with battery charging and occasional peak power demand assistance being provided by a 1.0-L gasoline engine. Although the company has actively promoted the U.S. $22,000 sales price of this model, it is, as with all of China’s other hybrid and alternative energy vehicles, primarily intended for purchase by government departments. The company has achieved a handful of sales to private buyers, however. The BYD-patented battery uses a proprietary iron chemistry that is said to be much more cost-effective, enabling it to provide an affordable challenge to lithium batteries. BYD had already shown a plug-in hybrid version of its midsize sedan, the F6 DM, at various motor shows and is planning to introduce this model in the next few months. The all-wheel-drive pure electric e6 lifestyle monobox concept vehicle, however, contrary to earlier production announcements, is now not expected to go into production within the next two or three years. CheryChery announced the 1.6-L A5 BSG (belt starter generator) last January and is working on a similarly equipped A3 sedan and hatchback for launch around the middle of the year. The A5 BSG’s purchase price makes it the only start-stop hybrid on the market available for under 80,000 yuan (U.S. $11,700). The company is also readying an ISG (integrated starter generator) mild hybrid version of the A5 sedan,　which it had already demonstrated during the Olympics. It links a 1.3-L engine to a 12 kW electric motor running on 151 V. Chery sent more than 100 production managers to work with Ricardo in the U.K.　to develop its BSG and ISG models. The　collaboration resulted in the design of not only the vehicles themselves but also included the vehicle controller, battery, and traction motor elements. Chery announced production of its S18 electric five-door　hatchback city car in February. It uses the same platform as the seven-model Faira city car range that will soon enter series production. A 40 Ah lithium iron phosphate battery provides　336 V current to power the 40 kW electric motor. Maximum speed is a claimed 120 km/h (75 mph) and range is 120-150 km (75-93 mi). A full charge takes 4-6 hours. FAWChina’s first domestic vehicle manufacturer is working on a full hybrid capable of running long distances under electric power. The B70HEV, also known as the Besturn, uses a bespoke AMT (automated manual transmission) and is expected to supply up to 20 units to Tianjin and Chengdu by the end of 2010. The ramp up to series production is expected in 2012. FAW also plans to produce 100 hybrid buses for Dalian and Changchun. GeelyGeely’s rounded little Panda city hatchback is currently being readied for the market in pure plug-in electric form, but the production date has not yet been fixed. Domestic manufacturers of pure electric and plug-in hybrids face the challenge of how to charge the battery: the vast majority of Chinese households do not have garages and do not have readily available power sources with which to charge their vehicles. This should not affect the electric Panda’s sales performance with regards to the current large-scale encouragement program. The Geely spokesman said, "Government departments generally have garage parking facilities where the vehicle can be recharged. The problem of where to charge the vehicle for the general public is still a challenge that needs to be solved, but we are working on it." Geely has also developed CNG and ethanol-powered versions of a number of its existing vehicles and already produces these in limited numbers. A new methanol-powered drivetrain is also being developed but as yet is unable to go to market because "the government has not yet established any rules for this power source." The challenge aheadThe Ministry of Finance’s launch of this massive hybrid and alternative energy program is obviously a source of great encouragement to the car manufacturers. But the issue of high cost remains, at least for the initial limited production runs. The OEMs obviously have their work cut out as they strive to bring costs down to acceptable levels, notwithstanding the generous subsidies that have been offered to ease the process. In addition to this factor, the automakers also have to ensure that their models are able to provide robust – three years or 150,000 km (90,000 mi) – fault-free performance, along with all the necessary servicing, spare parts, and maintenance network. With their low emissions and modern engine designs capable of meeting Euro 4 and 5 regulations, however, the makers of gasoline-engined cars appear　best placed to take early advantage of worldwide export opportunities for energy-saving vehicles in coming years. spoke to a number of domestic car manufacturers to see how the program was progressing. At present there is a high level of activity as manufacturers demonstrate vehicles and negotiate purchase contracts with various government bodies. Initial contracts are for small numbers of vehicles, but most manufacturers speak of a shift to series production within the next two years as volume increases and the costs begin to come down. China Brilliance, for instance, speaks of a gradual ramp up to volume production some time during the course of 2010-2011.

The Beijing Olympics saw a total of 80 hybrid and alternative fuel vehicles on public demonstration as ordinary taxis and transport for Olympic officials last year. After the Games the cars were quickly whisked back to their respective manufacturers and stripped down for evaluation. The Olympic hybrid car program had been the first stage in a far-reaching plan to gradually introduce China’s people to the concept of energy-saving and more environmentally friendly vehicles. The vehicles taking part had performed their onerous ferrying duties without fault, enabling the manufacturers to go on to the next stage in the process. Late in 2008, one of China’s newest car manufacturers, BYD of Shenzhen, announced the world’s first production plug-in hybrid car. A series of announcements by China’s other domestic car manufacturers surrounded this astonishing news. Brilliance announced its medium-powered hybrid at the Guangzhou fair in November and Chery put two models – one a hybrid and the other a fully electric car – onto the market early in the new year. The local press was full of environmental claims, but some of the prices were almost double those of conventional models. February 2009 saw the annual Chinese People’s Political Consultative Conference in Beijing, at which the Ministry of Finance publicly announced the provision of 10 billion yuan (around U.S. $1.4 billion) of extremely generous subsidies for purchasers of hybrid and alternative energy ("new energy" as they are known in China) vehicles. China’s new large-scale public demonstration and trial funded by the Ministry of Finance will take place in 13 large urban areas, including Beijing and Shanghai. Each local area is to purchase new hybrid and alternative energy vehicles, comprising government transport, public service (postal service and sanitation, for example) and public transport vehicles. The vast majority will be passenger cars and light commercial vehicles, and they will include mild, medium, and full hybrids, range extender hybrids, alternative fuel, and fully electric. Enormous subsidies are also on hand to support the purchase of heavy duty fuel cell buses. "We are investing a lot of money to ensure that each urbanized area takes at least 1000 vehicles, and if the program succeeds, it will help to raise private buyers’ awareness and acceptance of these new technologies and expand their coverage," a Ministry of Finance official who was unwilling to be named told AEI. The program will run for three years and the funds will come from various sources, including the state, local government, and local public transport authorities. The official said the funds will not be available up front for purchase of these vehicles. Instead, the money "will be refunded for each purchase upon production of the relevant vehicle purchase documents." Details of the subsidies: Trial regionsBeijing, Changchun, Changsha, Chongqing, Dalian, Hangzhou, Hefei, Jinan, Kunming, Nanchang, Shanghai, Shenzhen, and Wuhan Vehicle typeChinese yuanU.S.$Note Passenger car and light commercial vehicle subsidies HybridUp to 50,000$7315divided into five levels, depending on economy Pure electric60,000$8780 Fuel cell250,000$36,580 Hybrid fuel economymin. 5% improvement for light commercial vehicles, min. 10% improvement for passenger cars Subsidies for buses over 30 ft (9.1 m) long Hybrid80,000 - 420,000$11,700 - $61,450depends on battery chemistry (lead-acid, NiMH, or lithium) Pure electric500,000$73,150 Fuel cell600,000$87,790 The new subsidies will provide a healthy stimulus to ensure that high technology R&D on hybrid and new energy vehicle continues around the country – by universities, suppliers, and manufacturers themselves. One form of motive power that was conspicuous by its absence was the diesel engine. China faces a relative shortage of this fuel as a result of its relatively high production cost and competition for diesel and other heavy fuel oil by other industries in China.AEI spoke to a number of domestic car manufacturers to see how the program was progressing. At present there is a high level of activity as manufacturers demonstrate vehicles and negotiate purchase contracts with various government bodies. Initial contracts are for small numbers of vehicles, but most manufacturers speak of a shift to series production within the next two years as volume increases and the costs begin to come down. China Brilliance, for instance, speaks of a gradual ramp up to volume production some time during the course of 2010-2011.Details of current hybrid and alternative energy vehicles in China: Brilliance The BS6　"Zunchi" medium hybrid sedan uses a locally developed turbocharged 1.8-L gasoline engine. The electric traction motor is rated at 10 kW and uses an NiMH battery pack, which, along with the vehicle controller, is produced in the Shanghai region. The powertrain performs start-stop, regenerative braking, and boost functions, with a claimed improvement in economy of up to 35% against similar-sized sedans. Brilliance, which assembles BMW 3- and 5-Series sedans in partnership in Shenyang, has equipped the car with a manual gearbox. Negotiations to supply a limited number of vehicles to urban areas are ongoing. The company also has plans to introduce a mild hybrid vehicle in the near future, possibly based on its new FRV hatchback model. BYD Shenzhen-based BYD’s F3 DM plug-in hybrid is a "range extender."It uses an electric motor for traction, with battery charging and occasional peak power demand assistance being provided by a 1.0-L gasoline engine. Although the company has actively promoted the U.S. $22,000 sales price of this model, it is, as with all of China’s other hybrid and alternative energy vehicles, primarily intended for purchase by government departments. The company has achieved a handful of sales to private buyers, however. The BYD-patented battery uses a proprietary iron chemistry that is said to be much more cost-effective, enabling it to provide an affordable challenge to lithium batteries. BYD had already shown a plug-in hybrid version of its midsize sedan, the F6 DM, at various motor shows and is planning to introduce this model in the next few months. The all-wheel-drive pure electric e6 lifestyle monobox concept vehicle, however, contrary to earlier production announcements, is now not expected to go into production within the next two or three years. Chery Chery announced the 1.6-L A5 BSG (belt starter generator) last January and is working on a similarly equipped A3 sedan and hatchback for launch around the middle of the year. The A5 BSG’s purchase price makes it the only start-stop hybrid on the market available for under 80,000 yuan (U.S. $11,700). The company is also readying an ISG (integrated starter generator) mild hybrid version of the A5 sedan,　which it had already demonstrated during the Olympics. It links a 1.3-L engine to a 12 kW electric motor running on 151 V. Chery sent more than 100 production managers to work with Ricardo in the U.K.　to develop its BSG and ISG models. The　collaboration resulted in the design of not only the vehicles themselves but also included the vehicle controller, battery, and traction motor elements. Chery announced production of its S18 electric five-door　hatchback city car in February. It uses the same platform as the seven-model Faira city car range that will soon enter series production. A 40 Ah lithium iron phosphate battery provides　336 V current to power the 40 kW electric motor. Maximum speed is a claimed 120 km/h (75 mph) and range is 120-150 km (75-93 mi). A full charge takes 4-6 hours. FAW China’s first domestic vehicle manufacturer is working on a full hybrid capable of running long distances under electric power. The B70HEV, also known as the Besturn, uses a bespoke AMT (automated manual transmission) and is expected to supply up to 20 units to Tianjin and Chengdu by the end of 2010. The ramp up to series production is expected in 2012. FAW also plans to produce 100 hybrid buses for Dalian and Changchun. Geely Geely’s rounded little Panda city hatchback is currently being readied for the market in pure plug-in electric form, but the production date has not yet been fixed. Domestic manufacturers of pure electric and plug-in hybrids face the challenge of how to charge the battery: the vast majority of Chinese households do not have garages and do not have readily available power sources with which to charge their vehicles. This should not affect the electric Panda’s sales performance with regards to the current large-scale encouragement program. The Geely spokesman said, "Government departments generally have garage parking facilities where the vehicle can be recharged. The problem of where to charge the vehicle for the general public is still a challenge that needs to be solved, but we are working on it." Geely has also developed CNG and ethanol-powered versions of a number of its existing vehicles and already produces these in limited numbers. A new methanol-powered drivetrain is also being developed but as yet is unable to go to market because "the government has not yet established any rules for this power source." The challenge ahead The Ministry of Finance’s launch of this massive hybrid and alternative energy program is obviously a source of great encouragement to the car manufacturers. But the issue of high cost remains, at least for the initial limited production runs. The OEMs obviously have their work cut out as they strive to bring costs down to acceptable levels, notwithstanding the generous subsidies that have been offered to ease the process. In addition to this factor, the automakers also have to ensure that their models are able to provide robust – three years or 150,000 km (90,000 mi) – fault-free performance, along with all the necessary servicing, spare parts, and maintenance network. With their low emissions and modern engine designs capable of meeting Euro 4 and 5 regulations, however, the makers of gasoline-engined cars appear　best placed to take early advantage of worldwide export opportunities for energy-saving vehicles in coming years.

　

In-vehicle Networking

In-vehicle Networking:
As we all know that in the vehicle all electrical and electronics parts and components were connected through wiring harness to transmit signal / information from one point to another point. In conventional wiring harness system dedicated wires required for each and every signal. For few featured vehicle this system is good and cost effective but when we talk about a vehicle with luxury features, this system become more complex and costly. To avoid that complexity In-Vehicle networking comes in picture which is also known as multiplex wiring.
In-vehicle Networking
 –Connect the vehicle's electronic equipments.
 –Facilitate the sharing of information and resources among the distributed applications.
 –Change the point-to-point wiring of centralized ECUs to the in-vehicle networking of distributed ECUs.
Aims of In-vehicle Networking:
 –Open Standard
 –Ease to Use
 –Cost Reduction
 –Improved Quality
Benefits of In-vehicle Networking:
 –More reliable vehicle
 –More functionality at lower price
 –Standardization of interfaces and components
 –Faster introduction of new technologies
 –Functional Extendibility
 –Decreasing wiring harness weight and complexity
 –Electronic Control Units are shrinking and are directly applied to actuators and sensors

In-vehicle Networking or multiplexing is based on serial protocols. Modern automobile’s protocols are listed below

S.N Protocol Name Speed Use Origin
1 D2B 5Mbit/s High Speed electrical or optical mainly for digital audio Auto
2 MOST 22.5Mbit/s High Speed (audio, video, control) Auto
3 FlexRay 10Mbit/s High Speed x-by-wire, safety-critical control) Auto
4 Byteflight 10Mbit/s High Speed constant latencies, airbag, sear-belt Auto
5 TTP 5~25Mbit/s High Speed real-time distributed/fault-tolerant apps Auto
6 Bluetooth 10Mbits/s High Speed wireless for infotainment equipments Consumer
7 CAN 50-1000kbit/s Low Speed Controls Auto
8 J1850 10.4kbit/s and 41.6kbit/s Low Speed Controls Auto
9 LIN 20kbps Low Speed Controls Auto

 

Protocol Comparison:

 • Class A (<20 kbit/s) : LIN, CAN
 • Class B (50-500 kbit/s) : CAN, J1850
 • MMedia (> 20 Mbit/s) : MOST, Firewire
 • Wireless : GSM, Bluetooth
 • Safety : Byteflight, TTP/C, Flexray

1. D2B (Domestic Data Bus)
–Matsushita and Philips jointly developed
–Has promoted since 1992
–D2B was designed for audio-video communications, computer peripherals, and automotive media applications
 –The Mercedes-Benz S-class vehicle uses the D2B optical bus to network the car radio, autopilot and CD systems
 –The Tele-Aid connection, cellular phone, and Linguatronic voice-recognition application

2. Media-Oriented Systems Transport (MOST)
 –It was initiated in 1997
 –Supports both time-triggered and event-triggered traffic with predictable frame transmission at speeds of 25Mbps
 –Using plastic optic fiber as communication medium
 –The interconnection of telematics and infotainment such as video displays, GPS navigation systems, active speaker and digital radio
 –More than 50 firms—including Audi, BMW, Daimler-Chrysler, Becker Automotive, and Oasis Silicon Systems—developed the protocol under the MOST Cooperative

3. FlexRay
 –FlexRay is a fault-tolerant protocol designed for high-data-rate, advanced-control applications, such as X-by-wire systems (high-speed safety-critical automotive systems)
 –Provides both time-triggered and event-triggered message transmission
 –Messages are sent at 10Mbps
 –Both electrical and optical solutions are adopted for the physical layer
 –The ECUs are interconnected using either a passive bus topology or an active star topology
 –FlexRay complements CAN and LIN being suitable for both powertrain systems and XBW systems

4. Byteflight
 –Developed from 1996 by BMW
 –A flexible time-division multiple access (TDMA) protocol using a star topology for safety-related applications
 –Messages are sent in frames at 10Mbps support for event-triggered message transmission
 –Guarantees deterministic (constant) latencies for a bounded number of high priority real-time message
 –The physical medium used is plastic optical fiber
 –Byteflight is a very high performance network with many of the features necessary for X-by-wire

5. Time-triggered protocol (TTP)
 –It was released in 1998
 –It is a pure time-triggered TDMA protocol
 –Frames are sent at speeds of 5-25Mbps depending on the physical medium
 –Designed for real-time distributed systems that are hard and fault tolerant
 –It is going on to reach speeds of 1Gbps using an Ethernet based star architecture

6. Bluetooth
 –An open specification for an inexpensive, short-range (10-100 meters), low power, miniature radio network.
 –Easy and instantaneous connections between Bluetooth-enabled devices without the need for cables
 –Vehicular uses for Bluetooth include hands-free phone sets; portable DVD, CD, and MP3 drives; diagnostic equipment; and handheld computers.

7. Controller area network (CAN)
 –Was initiated in 1981 and developed by Bosch developed the controller
 –Message frames are transmitted in an event-triggered fashion
 –Up to 1Mbps transmission speed
 –It is a robust, cost-effective general control network, but certain niche applications demand more specialized control networks.

8. The SAE J1850 Standard
 –supports two main alternatives, a 41.6 kbps PWM approach (dual wires), and a 10.4kbps VPW (single wire) approach.

9. Local interconnect network (LIN)
 –A master-slave, time-triggered protocol
 –As a low-speed (20kbps), single-wire
 –LIN is meant to link to relatively higher-speed networks like CAN
 –LIN reveals the security of serial networks in cars
 –network is used in on-off devices such as car seats, door locks, sunroofs, rain sensors, and door mirrors

Exhaust Energy recovery

Even the most efficient IC engine of today can at the most squeeze out 25% of the fuel's energy and convert it into useful mechanical energy. The rest is wasted has exhaust heat, coolant heat, noise and friction(see image). Of this, significant amount is wasted as exhaust heat. It will be great break-through if this energy is tapped and converted into useful work. Three possible ways of tapping this energy
1) Petlier modules: Uses differential heat of exhaust and ambient temperature to produce electricity
2) Water tube boiler & turbine system: A miniature water tube boiler which uses exhaust heat to produce steam which can drive a generator attached to a turbine
3) Vapour absorption airconditioning: Use exhaust heat to cool the cabin by using vapour absorption refrigeration cycle.

The technologies mentioned in point 1 & 2 can replace the conventional alternator, reducing about 2kW load from the IC engine.

The technology mentioned in the mentioned in point 3 can replace the AC compressor, reducing about 3kW load from the engine.

Suming up we can recover atleast 5kW of useful energy from the exhaust, thereby giving 5kW additional power for traction from the same engine. Effectively the engine can be downsized, giving better fuel economy. If the concept proves successful and economical this could be big releif for customers at this time of rising fuel prices