Today, the use of innovative technologies in the automotive world has become a necessity for automakers. More stringent regulatory requirements on one hand and increasing expectations of customers on the other hand have made the car companies to plan extensive programs to develop and implement advanced technologies to gain more market share. Therefore; given to the vision of SAIPA Group that is achieving the highest share in domestic market as well as presence in international markets, SAIPA Automotive Industry Research and Innovation Center (AIRIC) has decided to prepare a road map for development of advanced technology and their use in future products, and supply them in vehicles with a variety of comfortable, safe and environmentally friendly equipments to its customers.
Enhancing vehicle safety by using traditional methods has limitations and progress is not possible without the use of innovative technologies. Although it suffice to conform with the legal minimum as a prerequisite for market entry, safe cars at the international level have equipments and accessories that are beyond the level of mandatory standards. International automakers for other reasons, including competitiveness and social responsibility, are pursuing to enhance further the safety of their cars; to achieve this objective they are applying the most advanced technology in their operation. Global NCAP as an international and non-profit organization, that has representative all over the world such as Europe, America, Australia and Japan, has been testing and rating the safety of cars for a long time.
This organization rates and ranks the safety of the cars on the basis of the level of safety equipment and collision test results in four areas: Occupant Safety, Child Safety, Pedestrian Safety and Safety Assist (smart driver assistance systems). The evaluation results are released publicly on its website. Customers can gather information on safety ratings through these assessments if they want to buy a car. Nowadays, most automakers assess their products before entering the market in these centers, and publish the rating results as proof of the safety of their products and also use the information as an effective promotional tool in attracting customers.
In recent years, issues related to the structural strength of the vehicle has become a solved problem so that today more efforts are focused on developing intelligent systems that help the driver. According to crucial role that these systems play in the prevention of accidents, the Euro NCAP institute has paid special attention to this topic so that if future cars are not equipped with systems such as Autonomous Emergency Braking-AEB, Lane Departure Warning System-LDWS, Adaptive Cruise Control and Intelligent Speed Adaptation-ISA as well as other advanced systems they will not be considered as qualified for assessment in Euro NCAP tests. By applying these technologies in future cars, SAIPA Automotive Industry Research and Innovation Center (AIRIC) intends to take an important step towards safety of esteemed customers.
Autonomous Emergency Braking System intelligently prevents collision with obstacles that may caused by inattention, drowsiness or distraction. The function of this system consists of two main stages, stage one alerts and stage two prevents from collision. In alert stage the sensors (cameras / radars) of the Forward Collision Warning (FCW) system detect obstacles and if there is a risk of collision, the system sends an audio or visual alarm to warn the driver. If the driver does not pay attention to warning signs or does not push the brake in time, the Autonomous Emergency Braking (AEB) attempts to avoid the obstacle. The performance of the system is shown in Figure 2. Based on Euro NCAP institute categorization, different types of Autonomous Emergency Braking include: urban (City AEB), intercity (Interurban AEB), pedestrian (Pedestrian AEB) and two-wheeled vehicles (Cyclist AEB).
Based on performed research it is expected that until 2020 the installation of AEB will be mandatory for all new passenger cars in Europe. Previously, according to the laws of European Union, AEB system has been mandatory for commercial vehicles since 2014.
Urban and Interurban automatic braking types have similar performance in terms of the nature and types of sensors as well as the types of detectible obstacles. Urban kinds are used in the metropolitan area for low speeds, while Interurban types are used for higher speeds in highways and roads.
Sensors used in urban types are mainly of short-range radar; and the range and viewing angles depend on the manufacturer and are, 60 m and 60 degrees respectively from the front of the vehicle; so the urban types are more suitable for speeds less than 50 km/h and can detect obstacles in a relatively large area of vision. Sensors that are used in these types can only detect 4 wheel vehicles but it is not able recognize other objects such as pedestrians, two-wheeled vehicles, trees, animals and road guard rails.
Interurban types use high-range radar sensors; depending on the manufacturer, range and the viewing angle are approximately 200 meters and 20 degrees respectively. Due to longer range sensors, Interurban types can be used at speeds up to about 200 km/h as well. But due to the lower viewing angle, they are not suitable for use in busy urban environments. The new generation of radar sensors, the angle and range of the sensors can be adjusted adaptively with the speed of the vehicle and can be used both for the city and for Interurban areas. Also Interurban type is only capable of detecting four-wheel vehicles like the urban types.
The best place for installation of the radar sensor is usually in windshield in front of the logo. To enhance the accuracy and reliability of the system a video camera is often used. The radar and camera data are combined and used with data fusion method to increase the system performance and reliability. The cameras are usually installed behind the windshield nest to rear view mirror of the vehicle. Although the camera is not mandatory for these types, since the camera is also used by other safety and assistant systems (such as road departure warning systems, traffic signs detection, pedestrian detection, etc.), its use in a variety of automatic braking systems is common.
AEB Pedestrian and AEB Cyclist brake systems are categories in safety systems to protect vulnerable road users. Thus, they are also known under the general title of AEB VRU (Vulnerable Road Users). AEB Pedestrian and AEB Cyclist system recognize the type of obstacles (pedestrians or two-wheeled vehicles) by using the camera installed in the back of the windshield as well as image processing methods to detect if the driver does not react in time, the system automatically activate the braking action. The cameras can be used either mono or stereo. If the system is equipped with stereo camera (i.e. two cameras together with a specified space between them) it will have the ability to measure depth of obstacles; otherwise a radar sensor may also be used to assess the distance to obstacles. Although radar is not capable of differentiating the obstacles, it is often used along with cameras to increase the accuracy of the information systems because of its accuracy in measuring the distances and because of the impact of weather conditions on its performance. Depending on the models, the range and angles of the cameras are different. But in ordinary types, the obstacles are detected with good accuracy and high resolution up to a distance of 40 meters. More advanced and more expensive type of cameras has high resolutions and can detect obstacles up to a distance of 500 meters.
Adaptive Cruise Control system keeps constant the speed of the car intelligently on the value that the driver pre-set. Hence, part of the performance of this system is similar to Cruise Control System. The only difference is that Adaptive Cruise Control detects cars and obstacles in front of the vehicle with the help of installed radar sensor, and if necessary, it intelligently reduces the vehicle speed. When there is no obstacle in front of the vehicle, the system increases the speed again to reach the pre-set by the driver. Usually safe distance with other vehicles is also pre-set by the driver. The default value is about 2 seconds and the driver can make it more or less due to weather and traffic. The system has three different types depending on their sensors range and algorithms:
Lane Departure Warning System uses a camera located on the front of the vehicle (behind the windshield) to recognize the road lines. When the vehicle approaches the lines due to driver distraction or lack of vigilance, audio or visual or tactile warning system (vibrating the steering wheel or the seat of the driver) warns the driver. When the driver uses the turn signals then the warning system is disabled. In more advanced systems, steering systems modifies the direction to prevent the driver from leaving the road unintentionally (Lane Keeping Assist).
Blind spot detection system warns the driver when there is a car or an obstacle at the sides and rear blind spots which are not visible in the car mirror to prevent from collision. These systems usually work with high range ultrasonic sensors in the rear bumper that scans the surrounding space. In some of these systems cameras are installed under the mirrors that can detect and recognize other cars or obstacles at the sides of the car.
In some forms of this system, if there is a vehicle in the blind spot and the driver wants to change lane without paying attention to the warning signs in the mirror, the system sends more serious warning via an additional action (such as audio warning or vibration in steering wheel or flashing lights inside the mirror). In a more integrated system the information from BSD and LDWS are merged and performance accuracy of the system is greatly enhanced.
The installed sensors in this system have the capability to detect the rear blind spot with 180 degree range of vision. When the driver wants to exit the parking lot, the BSD sensors scan the rear space 180-degree wide and if an obstacle is approaching, the system warns the driver. This function of the system is known as Rear Cross Traffic Alert (RCTA).
In a typical speed limit warning system, when the car exceeds a predetermined speed (for example 120 km/h) an audio and visual warning is sent to the driver. But in Intelligent Speed Adaptation System speed limits are set according to the speed limit signs of the road; and a warning signal is sent to the driver. If the driver ignores the warning system, the system can prevent the increase in vehicle speed. This system can be deactivated by the driver like other intelligent safety systems. Speed ??limit detection is performed in two ways:
This intelligent system assesses the environmental conditions and, if necessary, enable or disable high beam. Light sensors and cameras mounted on the front of the vehicle measure the brightness of environment and surrounding vehicles and depending on the circumstances they apply the necessary instructions to enable car's high beam.
The conditions under which the High Beam Assist is enabled:
The conditions under which the high beam assist is disabled:
Environment and Energy Consumption
The increase in emissions of greenhouse gases such as Carbon dioxide (CO2), Methane (CH4), Nitrous oxide (N2O), Fluorinated gases (F-gases)) and the consequently exacerbation of the of global warming phenomenon have caused increasing global pressures to reduce production of these gases, especially carbon dioxide (CO2). These pressures lead to legislation and regulations for limiting carbon dioxide emissions and fuel consumption.
Figure 3: Comparison of greenhouse gas emissions from different sectors
For example, next restriction in Europe is to achieve CO2 less than 95 g/km is 2020. CO2 emissions in vehicle correlate with fuel consumption and by reducing fuel consumption CO2 emission reduces too.
Figure 4: Program and trends of reducing CO2 in different countries
These pressures made automakers to look for solutions to reduce fuel consumption. Improvement in combustion engines has been one of the most effective solutions. Since 1998 the automotive industry achieved a huge success in upgrading combustion engines in two main technologies that are promising for more improvements:
On the other hand, achieving higher power along with lower fuel consumption has always been one of the motivations of customers to buy cars.
Many technologies are used to reduce fuel consumption; in the figure below an example is shown with the percent its effectiveness:
To create combustion three factors are required: air (oxygen), the fuel (petrol, diesel, etc.) and heat. This law is also true for internal combustion engines; the quality and amount of these three factors plays a significant role in producing power in a combustion engine. Contrary to popular perception, the amount of fuel entering the engine does not determine the output power; but it is the amount of air entering the engine that determines how much power can be expected because the amount of fuel injection is a function of the amount of air entering into the engine. It could be said that the engine output power is in direct proportion to the amount of entering air.
Since the Electronic Control Unit (ECU) system of the engine tries stoichiometrically to keep fuel-air ratio (1 gram of fuel per 14.7 grams of air) at each stroke; except for special cases (such as starting the engine when it is very cold or for the engines with specific functions). Therefore by increasing the volume of air entering the cylinder, fuel injection increases and consequently a stronger combustion will occur in the engine.
Considering this fact, automakers and engine designers have always tried using different methods to control the amount of air entering the engine; and when high power is not needed, less air enters into the engine; likewise when the high power is needed such as high speeds and acceleration, the required air is fully supplied.2.1.1 Engine Technologies effective to reduction of fuel consumption
As was explained, improving and increasing the volume of air entering the engine could have a significant impact on the increase in power and torque, therefore a smaller engine can be used to produce the same amount of power and torque which in turn reduces the fuel consumption.
On the other hand, by changing engine speed, the engine air intake also changes and at low speeds (due to high air pumping losses) and high speeds (due to high speed of opening and closing of the valves and insufficient time to fill air in thecylinders) engine produces less power than their capacity.
This technology helps engine to intake better by changing the effective length of the manifold: at low rpm (by making a long air path) at and high rpm (by making a shorter air path) and thus help increase torque and power output of the engine. The technology works by using a phenomenon called supercharging effect.
To use multiple ports for entry and exit of air in the cylinder is one of the effective steps to improve engine intake. Besides this technology, the use of variable valve timing technology can have a significant impact on the increased horsepower. As we know, the amount of air entering the cylinder depends on the time of the valve to open and to close and also the duration of opening and closing; these all depends on the cams and angle of the camshafts. By using VVT technology it become possible that at high speed the valves open sooner and close later in order that the air have enough time to enter the cylinder.
This technology also has a philosophy similar to VVT, except that the displacement of the valves has changed and with more opening of the valve, more air enters the engine.
Cylinder DeactivationThis technology is more used in engines with high displacement to reduce fuel consumption and emissions during the time that less power is required. In part load conditions that the driver typically uses 30% of engine power, the valves are almost in closed position and pumping loss increases. In order to reduce this loss, the engine control system deactivate some of the cylinders.
Downsizing is another technology that has a significant impact on reducing fuel consumption and the size of the engine. This technology has a negative consequence that is the loss of engine power. To compensate for the reduction of engine power, engine designers again have to think about air controlling technologies and adding turbochargers or superchargers.
Reducing the amount of fuel for ignition, increasing quality of combustion by improving the incomplete combustion process are among other methods that are used to reduce fuel consumption in vehicles. Some of these techniques include:
Direct fuel injection has been used in diesel engines for a long time, but its use in gasoline engines faced with problems. The development of electronic control systems with a more detailed analysis of the combustion process helped to develop the technology and its mass production is reached in the late 90s.
Fuel dilution belongs to direct injection engines category in which the air-fuel ratio can vary up to 40 and even more (weight ratio). Pumping losses decreases and efficiency increases because of the high proportion of air entering the engine.
One of the major problems with direct injection engines is the increase in the temperature of combustion gases and hence NOx emissions. However, better combustion in these engines reduces the carbon emissions, but on the other hand leads to an increase in temperature of the combustion gases provide a suitable environment for the production of NOx. One design solution is to re-use the exhaust gases. These gases are almost neutral in terms of chemical reaction because they occupy a part of the cylinder volume, therefore less fuel is injected in to the chamber, as a result the combustion temperature and fuel consumption is reduced.
Hydraulic assist steering wheels cause more losses of power due to permanent connection to the engine crankshaft. By applying electric steering system much of these losses are minimized and only during times when the driver is going to turn, the power of the engine (the electric power) is used. The electric power steering system helps to improve fuel consumption by reducing hydraulic power losses.Using Intelligent Alternator
In this system, the torque is controlled intelligently by alternator that has the following advantages:
In combustion engines, some of combustion heat spreads into the engine and cause overheating of the engine; engine cooling is carried out by water pump that circulates cooling liquid mechanically with a belt from the engine crankshaft; therefore some power produced by the engine is consumed. Also the speed of the pump is the same as the speed of the crankshaft and there is no feedback from the engine temperature. Replacing electric water pump with mechanical water pump decreases power consumption due to removing the belt and pulley from engine. The engine cooling is done quite smart because the engine gets temperature feedbacks from radiator and keeps the engine temperature normal which in turn reduces fuel consumption.
The performance of electric oil pump is similar to electric water pump.Cooling fan with variable speed
Most of the fans that are used for cooling engine's fluid have one or two rounds and are controlled by a thermostat. In other words, after the engine water temperature reaches to specified threshold, the fan starts to work and the temperature reaches to a low level, then the fan stops. If a fan with variable speed is used, electrical loads can be managed efficiently; and in addition, the engine optimum temperature can be controlled and thermal efficiency can be improved.Air conditioning with Electric Compressor
The benefits of this technology are:
Development and improvement of existing technologies in the field of powertrains and the vehicles has a higher priority to electrification of the vehicle because of needed budgets and the level of technology. But it should be noted that the effectiveness of this technology is limited and to achieve long-term goals to reduce fuel consumption and CO2 emissions there is no other options rather than to apply electrical technologies.
In city driving, 35% of the time on average the engine of the vehicles works in idling mode. When the car doesn't move, turning off the engine can help to reduce fuel consumption. Automatic Stop-Start (STST) refers to a system that detects the vehicle status mode and when there is no need to combustion engine operation, such as a full stop at red lights (first generation) or in the case of speed reduction to a complete stop (in more advanced generation of the system), the engine turned off; as soon as the driver decide to move, the system starts the engine again. It should be noted that this system is capable of a 10% reduction in fuel consumption in urban traffic.
Vehicles equipped with combustion engines gave high-performance, reasonable mileage, acceptable cost and weight; however, they consume fossil fuels and produce emissions and greenhouse gases. On the other hand, electric vehicles do not consume fossil fuel and are emissions-free (where they are used), but they have low mileage and their functionality are not desirable; in addition to the fact that their initial cost is much higher than conventional vehicles with gasoline. The vehicle and powertrains designers are always looking to build cars with the lowest emissions and fuel consumption, highest mileage and functionality with reasonable cost. Hybrid-electric vehicles were the response of designers to the needs of automotive industry. These cars use two sources (generally electric and combustion) to provide thrust for the vehicles. Hybrid vehicles entered commercial stage with the arrival of the Toyota Prius hybrid cars since 1997 and then in 1999 with the Honda Insight, and then many companies attempt to supply their own hybrid models.
Hybrid vehicles are supplied according to the capacity of the battery and the power of electric engine in different models such as Micro Hybrid, Mild Hybrid or Full Hybrid. Due to increased engine power of electric vehicles, the capabilities for all-electric car also increased accordingly; therefore proportionately the price of these cars, their complexity of manufacturing technology and the improvement in fuel consumption has increased.If hybrid cars also have the ability to be charged from exterior source then they are called Plug-in Hybrids. This design of the hybrid vehicle usually has lower fuel consumption, more electric mileage and higher prices than a non-plug in hybrids.
Figure 11: Plug-in HEV Toyota Prius
Figure 12: A typical HEV Toyota Prius
As the name suggests, Electric vehicles use the electrical energy to produce their driving force. This electrical energy is generally extracted from high-capacity storage batteries (lithium) and it is converted into mechanical energy in electric engines. After draining, the batteries need to be recharged by external electrical source. Electric cars that produce no pollution where they are used (pay attention to this fact that zero emission here does not mean that the eclectic power is without emission from production to consumption or as the saying from well to wheel) are a suitable option to improve air quality, especially in crowded cities and downtowns. But the mileage of these cars as well as their driving capabilities greatly depends on the type and capacity of their battery and electric engine, therefore their development and success depends on the technology of the battery and the engine. However, electric vehicles are expected to gain considerable share of the car market in the coming decades.
Vehicles equipped with fuel cell are the future generation of electric vehicles where the energy comes from the chemical reaction between hydrogen and oxygen that produces water vapor and electricity; and finally the electric engine is used to drive the vehicle. Recently the South Korean company Hyundai has commercialized the first fuel cell-powered car in Tucson's model and has shipped to America.
Figure 13: Schematic Toyota fuel cell-powered car
Passenger Comfort and Accessories
Today, the variety of products and their differentiation to competitors are keys to success for automotive company in a competitive market. Successful automakers leave a track in their products so that using their vehicle makes a unique experience for customers. Passenger comfort and accessories have an important impact to realize this experience. This effectiveness is evident in competitiveness of the vehicle and in promoting customer satisfaction and thus their loyalty. On the other hand, technologies in passenger comfort are complementary efforts to realize the goal of "safe driving" with reducing driver fatigue and increasing the level of driver focus. Also this area is divided into several sub-sectors, most notably connected car, driver comfort, ergonomics, ventilation, exterior appearance and the interior appearance of the car.
Today, the produced vehicles are equipped with systems such as Telematics, Navigation, Multimedia and Infotainment; these vehicles are called Connected Cars. Besides Some features of this system are customer relationship management, troubleshooting, coordinating repairs and vehicle health management, stolen vehicle tracking, detecting and combating the causes of automobile accidents by installing non-original products. In additions, dozens of other features exist that can be executed by the system. According to estimates by 2020, almost ninety percent of cars produced worldwide will be connected.
Park Assist Systems are another area of driving comfort that focuses on embedded systems in vehicles that can take part in the main tasks of the driver. Among these technologies, park assist system is studied in the field of occupant comfort. Among the features of the system are helping to park the car by installing cameras on the front and rear, semi-automatic or automatic parallel and perpendicular parking, identifying suitable parking spaces and many others. According to forecasts, by 2018 nearly 88% of the cars produced in the UK market will be equipped with a high level of these systems. Other countries, such as China's market has the same situation with a little delay.
The infrastructure for this system is already available in cars. The system uses a combination of rear view camera and a monitor inside the car. The point is that with software development based on the integration of image processing and sensor data about the objects in the rear of the car, necessary guide can be given to the driver about the path for parking the car.
This system uses the same sensors that are used for reverse sensor in the front bumper which is two in small cars and four in larger ones that have the full version of the system.
When, for safety reasons, a camera is installed in front of the vehicle to run features such as Lane Departure Warning, the camera image is displayed on the vehicle display inside the car that can be added to the image data to guide the driver.
This feature can be implemented in vehicles equipped with electric power steering system. Its function is as follows: The suitable route for parking the car is extracted by processing data from ultrasonic sensors the driver only needs to push acceleration and braking pedals. Of course the system can process data gathered by rear camera and consider it in planning the next movements.
This system can be activated by the driver request or a preset vehicle speed. The system uses two long-range ultrasonic sensors installed on one side, and by using data from vehicle sensors it chooses the perfect space for parking the car and arranges for the execution of the other algorithms.
This system covers all stages of parking the car and instructs the acceleration, brake and steering wheel, but still needs the driver's attention as an observer to monitor the route. Simpler mode of the system is the Semi Automated Parking-Steering only) but the chronological order is the same.
This system is also called Maneuvering Assist. This system guides the driver in carrying out tasks during low-speed maneuvers. In its simplest form the system issues a warning and in more complex scenarios it assumes the control of the vehicle. This system is most effective in crowded maze-like environments such as entrance to the apartments and public parking lots and other similar spots.
Park assist systems generally focus on the entrance to the parking space but exit from the parking space in narrow lanes and urban environments is more complicated operation than entering it. This system is devised based on the concepts of low-speed maneuvers assist system and is responsible for the exit from parking space. All the sensors that are used in other systems are used here, and if it is possible entry route to the parking space will be saved.
HUD system displays driver's needed information on the windshield to create more focus and decrease driver distractions. This system uses a video projector embedded at the back of the dashboard and displays information such as speed, navigation directions, limit signs, mobile phone caller information, warning from safety systems (ADAS) etc. on a semi-transparent or windshield glass (with special material). Driver can see this information while driving without losing front view. Hence, this system can play a role in the prevention of accidents caused by inattention or distraction.
Nowadays vehicle ergonomics considerations play an important part in car design. The impact of these systems on driver fatigue and safe driving is unavoidable. On the other hand, the advanced technologies in this field have great impact on the popularity of new products. As it can be observed, in some cases, there are car models with old standards which become popular only by using these technologies. Several technologies are used in this field, including electric adjustable seats with memory. In this case, the driver set the seat in a desired mode and the system stores the optimal position.
These systems have a significant impact on the increase in comfort and driving pleasure, and on the other hand they reduce driver fatigue. In BMW technology manual, driver seat cooling system is introduced as a technology that has a huge impact on driver fatigue and thus the safety of the car.
On the other hand, automatic adjustment systems of the temperature with adjustable temperature in different spots have been widely used nowadays.
Also there are systems for automatic air circulation inside the car to keep the air inside the car healthy and protect occupants against outside air conditions which may not be healthy enough.
The important point about these systems is that each of these systems such as ergonomics and air conditioning etc. not only have their own direct impact but also they have a significant impact on the competitiveness of the car. Considering the increase in cost of applying these technologies in vehicles, auto makers have reached the solutions to express the purpose of installing such systems to facilitate the acceptance of these increased costs by customers. For example, Nissan Company has introduced ergonomics System as "Well-being Concept" and stated that this can facilitate blood circulation in the body of the driver. Using this tactic, Nissan not only has set a target to increase this spending but also made the customer accustomed to Well-being Concept that in turn leads to customer's loyalty too.
Given the significant number of controlling units in SAIPA future platforms, there is an urgent need to a reliable electronic base for the exchange of information between these units. Using car networks such as CAN not only meets these needs, but also provides capabilities and additional tools for automakers. SAIPA as an automaker with an international vision is developing the necessary electric and electronic infrastructure for future products to apply different kinds of advanced systems in future cars. Some features of this integrated electronic network include:
Various applications of car network can be summarized as follows:
CAN or Controller Aria Network is one of the most widely used vehicle communications protocols. CAN protocol has Multi Master's capability and also has the ability to adapt to different applications and data exchange capacities within the car. Different classes that can be used in cars and their applications are summarized as follows:
|Transfer rates||Low data rates (up to 10kBit/S|
|Application||Actuator and Sensor networking (Ex. Ultrasonic parking sensor)|
|Transfer rates||Average data rates (up to 125 kBit/S)|
|Application||Complex mechanisms for error handling, control unit networking in the comfort functions|
|Representative||Low speed CAN|
|Transfer rates||High Data rates (up to 1MBit/S)|
|Application||Real-time requirements, control unit networking in the drive and running gear functions|
|Representative||High speed CAN|
|Transfer rates||Extremely high data rates (Up to 10 Mbit/S)|
|Application||Real-time requirements, Control unit networking in the drive and running gear functions|
|Transfer rates||Extremely high Data rates (>10MBit/S)|
|Application||Control unit networking in the Telematics and multimedia functions|