Crash Prevention Active Safety

Transcription

1 In-car safety technologies provide three distinct and equally important functions. The first category of technologies concentrate on providing active safety that assists drivers to avoid crashes. The second provides more passive safety by providing protection to drivers and passengers in the event of a crash. The third category of technologies provide assistance to the driver. RACV recommends that when buying a new car, it is preferable to, at a minimum, have Electronic Stability Control (ESC), front airbags, and side and curtain airbags. Crash Prevention Active Safety Electronic Stability Control (ESC) Lane departure systems Emergency Brake Assist (EBA) Traction control Anti-lock Braking Systems (ABS) Injury Prevention Passive Safety Front airbags Side and curtain airbags Driver Assistance Adaptive headlights Adaptive Cruise Control (ACC) Satellite Navigation devices (Sat-Nav) Parking sensors Rear-vision cameras Detailed descriptions of each of the technologies are provided in the following pages. 1

2 Crash Prevention Active Safety TECHNOLOGY ESC What does it stand for? Electronic Stability Control. What does it do? ESC can prevent crashes by helping drivers to keep control of their car when skidding or swerving suddenly. ESC senses when a driver is losing control of their car and will attempt to bring them safely back on track. ESC starts to intervene when the vehicle travels on a different course than that intended by the driver. This typically occurs when a driver tries to turn very hard (swerve) or tries to turn on a slippery road. Then the vehicle may understeer or oversteer. Understeer can be described as when the vehicle does not turn as much as required to negotiate a bend or avoid an obstruction. This occurs because the front wheels have lost traction with the road. Oversteer is the opposite. It occurs when the vehicle turns more than the driver intends because the rear wheels have lost traction with the road. If left unchecked, the oversteer may lead to a spin, while understeer may eventually result in failure to negotiate a bend or veering into adjacent lanes of traffic. The system is particularly effective when driving on a slippery road surface or on gravel where control is more likely to be lost. Some ESC systems will intervene sooner than others but they all ultimately do the same thing. How does it work? ESC builds on the components already present for ABS and traction control. It uses the wheel speed sensors and the ability to apply brake pressure to individual wheels but adds a steering angle sensor and a sensor that detects the direction of the vehicle. Some advanced systems also have body roll sensors that add more sophistication to the system. ESC continuously compares the driver s commands to the actual direction of travel of the vehicle. When the control unit detects a discrepancy, ESC intervenes by automatically applying the brakes to an individual wheel. In some cases, it will reduce the engine power as well. The intervention of ESC helps the driver to maintain control of the vehicle. Some vehicles are fitted with switches that either delay or completely remove intervention from ESC. This allows the driver to decide how to control the vehicle in situations where they fully expect it to slide and swerve (e.g. in snow and ice). What does it feel like when it is used? A driver is more likely to hear the system than feel its effects. Depending on the system, the driver may hear a groaning noise which comes from the brake system or from the wheel momentarily skidding. Benefits of ESC: Correcting oversteering or understeering; Stabilising the car during sudden steering movements (e.g. swerving); Studies have indicated that the system reduces the likelihood of crashes by about 34 per cent. 2

3 What is it also referred to as? Electronic Stability Program (ESP); Dynamic Stability Control (DSC); Vehicle Stability / Swerve Control (VSC) or Active Stability Control (ASC). Is it a standard or optional feature? ESC is standard in about 60 per cent of new car models and is an option on most others. Installation: ESC technology is installed during manufacture it cannot be retrofitted. Cost: Typically around $1,000 as part of a safety pack. TECHNOLOGY Lane departure systems What does it do? Lane departure systems are designed to help reduce crashes by alerting drowsy or distracted drivers when the vehicle has wandered out of its lane. How does it work? Most systems rely on the detection of the vehicle s position in relation to the road lane markings. With the help of a small camera mounted on the vehicle and other sensors (e.g. speed sensors and angle sensors) working under the direction of an on-board computer, the systems detect when the car is beginning to move out of its lane. They then warn the driver by sounding an alarm, vibrating the steering wheel and / or by flashing lights within the driver s sight (e.g. on the windshield or dashboard). Some of the more sophisticated systems will also work with the vehicle s ESC systems to apply the necessary braking and steering wheel angles to return the vehicle to its lane. Benefits of lane departure systems: These systems have been developed in response to the high proportion of crashes that are caused by vehicles wandering into on-coming traffic, and are designed to both alert drivers and help them keep to their correct driving lane. What is it also referred to as? Vehicle Lane Departure Prevention Systems or Lane Keep Systems. What does it feel like when it is used? These systems are not designed to compensate for the driver who intentionally veers to the other side of the road, nor for when drivers wish to change lanes in the normal manner. When the system engages, drivers will hear a warning sound and/or feel a gentle movement of the steering wheel back towards the correct lane. If a driver signals an intentional and normal lane change, the entire system will be overridden. Is it a standard or optional feature? This is still largely a high-end optional feature from makers including Volkswagen and Volvo. Installation: Lane departure systems are installed in new cars during manufacture. 3

4 TECHNOLOGY EBA What does it stand for? Emergency Brake Assist What does it do? EBA detects when emergency braking is required and helps the driver to increase brake pressure to stop the vehicle sooner than if the driver were acting alone. How does it work? EBA technology has been around since the mid 1990 s and is now well established in most new vehicles. It uses speed and braking sensors to detect when the driver is not applying sufficient pressure in an emergency situation to bring the vehicle to a safe stop. Working in tandem with Anti-lock Braking Systems (ABS), EBA is able to apply maximum braking to the point where ABS takes over and stops the wheels locking up. Benefits of EBA: Studies have shown that most drivers are generally too slow to react when heavy braking is required and are not sufficiently forceful in braking in an emergency situation. EBA is designed to detect when emergency stops are required and to apply maximum braking within milliseconds far faster than human reactions alone. Stopping can be much quicker and many crashes, particularly rear-end collisions, can be avoided. What does it feel like when it is used? Drivers will generally not know that EBA has kicked in unless they can compare an EBA-equipped car with one that does not have it. They will be able to feel the EBAequipped car stop much more quickly and with far less braking effort. Is it a standard or optional feature? EBA is now standard in most new cars in Australia. Installation: EBA is installed during manufacture and cannot be retrofitted. Cost: EBA is standard on many new car models, or part of a safety pack with ESC which typically costs $1,000. TECHNOLOGY Traction control What does it do? Traction control maximises grip and stability of the car on the road during acceleration, particularly in wet conditions or on loose gravel, helping the driver to maintain control of steering. A wheel that is spinning is no longer effective for steering, acceleration or braking since it has lost traction with the road surface. How does it work? A computer monitors the rotation of each wheel, checking for any sign of excessive wheel spin which is similar to, but essentially the reverse, of what ABS monitors. Traction control stops excessive wheel spinning by reducing engine power or temporarily applying the brakes to the affected wheel, allowing the car to regain traction. What does it feel like when it is used? Generally, the driver won t feel much, although an observant person might notice a slight jerking sensation as the brakes grab (this is particularly noticeable when on an inclined surface such as a boat ramp), however, the driver will remain in control of the car. 4

5 Is it a standard or optional feature? Traction control is generally integrated as part of the ESC system and is standard on about 60 per cent of new cars. It is optional on most other cars. Installation: Traction control is installed during manufacture it cannot be retrofitted. Cost: Standard on many new cars or about $1,000 as part of a safety pack. TECHNOLOGY ABS What does it stand for? Anti-lock Braking System. What does it do? When a driver brakes hard and suddenly in an emergency situation, ABS prevents the car s wheels from locking up. Car steering is only effective when the road wheels are turning, so by preventing the wheels from locking, the driver maintains steering control while being able to apply the maximum braking force. ABS is particularly beneficial in wet conditions or on slippery surfaces where wheel locking is more likely to occur. It will also help to keep the vehicle stable under braking, particularly where one side of the car has more grip than the other (for example, on roadside edges). Without ABS, it is common for a vehicle to pull severely left or right when braking on loose surfaces (such as gravel), even if the vehicle is travelling in a straight direction. How does it work? An on-board computer monitors how quickly each wheel is rotating. If the brakes are applied and the computer senses that one of the wheels has stopped, or is rotating much slower than the others, the brake on that wheel will be released slightly, allowing it to start turning again. Benefits of ABS: Helps the vehicle pull up straight on all surfaces; Allows the driver to steer and brake heavily at the same time; Allows optimum braking force to be applied, even by inexperienced drivers. What does it feel like when it is used? Do not be alarmed by a whirring noise and pedal pulsations when braking hard. These conditions are normal when ABS is active and are an indication that the system is working. It is important to maintain full pedal pressure until the vehicle has reached the desired deceleration. Drivers should not lift their foot off or pump the pedal. ABS switches on and off every time the driver applies and releases the brake pedal, so lifting their foot off the pedal during braking will increase the stopping distance. Is it a standard or optional feature? ABS is standard on almost all new car models. ABS is generally integrated as part of the ESC (Electronic Stability Control) system on vehicles with this feature. Installation: ABS is installed in new cars during manufacture it cannot be retrofitted. Cost: No extra cost on most cars. 5

6 Injury Prevention Passive Safety TECHNOLOGY Front airbags What do they do? In the event of a severe frontal collision, front airbags can prevent the driver and passengers from hitting their heads and chests on hard surfaces inside the car such as the dashboard, steering wheel and windshield. How do they work? Upon impact, crash sensors can detect the sudden reduction in speed and will send a signal to the front airbags, which will rapidly inflate, forming a protective cushion as the head and chest of the driver or passenger are thrown forward. A typical 50-litre driver airbag can fully inflate in 50 milliseconds, while a front passenger airbag can typically inflate to a full 120 litres in just 54 milliseconds. This is an extraordinary speed, given that, on average, the blink of a human eye takes approximately 300 to 400 milliseconds! If there is no front seat passenger, some cars are designed to deploy only the driver s airbag. Since airbags are considered supplementary to seat belts, vehicles sold in Australia are normally set up to inflate the airbags only in the event of a severe crash. Where are they located? Front airbags are typically located in the centre of the steering wheel and above the glove box on the passenger side. Is it a standard or optional feature? Front airbags are a standard feature on all new cars and most light commercial vehicles. Installation: Airbags cannot be retrofitted. After they have been inflated, airbags cannot be repacked and the whole bag assembly must be replaced. TECHNOLOGY Side and curtain airbags What do they do? During side collisions and roll-overs, curtain airbags provide head and upper body protection for the driver, front passenger, and left and right rear passengers. Side impact airbags (sometimes also known as torso airbags) provide additional chest and upper body protection for the driver and front passenger. How do they work? In the event of a side impact collision, crash sensors send a signal to the side airbags and curtain airbags so that they rapidly inflate. Curtain airbags usually drop down from the roof above the doors along both sides of the car. They spread like a curtain over the side windows, forming a cushion that protects the driver s and passenger s heads from hitting the windows or other hard surfaces. Most are designed to remain inflated if the car rolls. Side airbags typically come from the seats and are designed to protect the area between the hip and head. They can be made to supplement curtain airbags. Generally, they are only designed for the front seat occupants but in some models side airbags are also provided for rear seat passengers. 6

7 Where are they located? Curtain airbags are located above the doors and side windows, while side airbags are generally located in the side of the front seat or in the door. Are they a standard or optional feature? Side airbags are standard on the majority of new cars, and curtain airbags are at least an option on most cars. Installation: Side and curtain airbags are installed only in new cars during the manufacturing stage and cannot be retrofitted. After they have been inflated, the whole bag assembly must be replaced. Cost: Where optional, they typically cost around $1,000 as part of a safety pack. Driver Assistance TECHNOLOGY Adaptive headlights What do they do? Adaptive headlights use sensors to control the car s headlights so that the driver can see the road better, particularly around bends in the road, providing a clearer view of what s ahead. How do they work? Using electronic sensors, adaptive headlights follow the direction that the steering wheel is turned. Some systems are speed-sensitive and others may adapt to changing road surface height (such as speed humps). The most sophisticated systems use Global Positioning System (GPS) information to predict upcoming corners. Is it a standard or optional feature? Adaptive headlights are still a high-end option on a limited, but increasing, range of new cars. Installation: Depending on the design of the system, it may be possible to retrofit adaptive headlights if the model featured them as an option. Additionally, they are available as after-market driving lamps which use a GPS system to provide the direction and speed information from which they alter the angle of the beam accordingly. Cost: An after-market system may cost $1,000 plus. TECHNOLOGY ACC What does it stand for? Adaptive Cruise Control. What does it do? What does it do? ACC is similar to standard cruise control with the added advantage that it automatically adjusts the speed of the car to keep a set distance from the vehicle ahead. 7

8 How does it work? Using electronic sensors and radars, ACC monitors the distance and speed of vehicles in front of a car and adjusts the acceleration and brakes of the vehicle to keep a set distance from them. It does this when there are changes in traffic speed, or if another vehicle cuts in, or if it detects another object on the road. If the system senses a potential collision, it will typically brake hard. Once the road is clear or the traffic has sped up again, it will return the car back to the speed at which it was set. Most ACC devices will allow the driver to select a gap they are comfortable with. As with standard cruise control, the driver can override the system at any time by simply touching the brakes. Is it a standard or optional feature? Adaptive Cruise Control is a high-end technology fitted to prestige vehicles, usually as an expensive option. However, it is expected to become available on more models in the future. Installation: ACC is installed at the factory. Cost: Typically about $4,500 to $5,000. TECHNOLOGY Sat-Nav What does it stand for? Satellite Navigation. What does it do? A Satellite Navigation device is like an electronic street directory on a small viewing screen. It not only shows the driver how to get from one place to another (giving point-to-point driving directions) but also calculates the time it will take for them to get there. The system will also put the driver back on track if they miss a turn. In addition, it will show the speed at which the car is travelling. A Sat-Nav can provide directions to petrol stations, ATMs, police stations and hospitals, among other things, and advise how far away they are. How does it work? Sat-Nav devices connect to a series of satellites to calculate where the driver is at any given time. Then, using electronic maps inside the system, they use their position to calculate the best route to the chosen destination and estimate how long it will take to get there. Benefits: The driver knows where they are going and they won t get lost. Even if they miss a turn, a Sat-Nav will re-calculate a route automatically and get them to where they need to be; It is much safer than reading a map while driving; Improves the safety of driving at night and in low-visibility conditions by giving the driver better road awareness it will warn them of an upcoming turn or exit long before they can see it; It tells the driver which lane to be in well in advance of an upcoming exit. Is it a standard or optional feature? Sat-Nav can come as an embedded optional extra on most new cars where the screens, maps and audio components are integrated into the vehicle s dashboard. It can also be an after-market, standalone unit that can be moved from one vehicle to another. 8

9 Installation: As an embedded feature of a new car, Sat-Nav can only be installed at the factory, but embedded after-market systems can also be installed professionally. As a standalone device, it can typically be bought at electronics shops, car accessory retailers and some department stores. It is very simple and easy to set up it simply plugs into the cigarette lighter. For safety and visibility, it should be attached to the lower right side of the front window and not in a position which obstructs the driver s vision. Cost: As an option on a new vehicle, they cost in the range of $2,000 to $3,500. As an after-market device that can be purchased and set up, Sat-Nav sets range from $120 to $920. TECHNOLOGY Parking sensors What does it do? Parking sensors detect objects (e.g. poles, cars, bushes, trees, walls, animals or people) that are behind or in front of a car and warn the driver of their presence. They do this by providing an audible or visual signal which rises in pitch or frequency as the driver moves closer to the object. How does it work? Ultrasonic, laser or radar sensors positioned in the front or rear bumper bars (or wherever the sensors are installed) monitor the distance (spanning from 30 centimetres to two metres) between the car and any detectable object it may be approaching, and provide an audible warning when it is getting too close. The system works automatically when the car is put into gear. Benefits of parking sensors: Warns the driver of nearby obstacles; Easier to park at night and in dimly lit areas. Is it a standard or optional feature? Parking sensors are an optional extra on most new cars. Installation: Parking sensor systems are usually installed at the factory, although after-market systems are available. Cost: Approximately $300. TECHNOLOGY Rear-vision cameras How does it work? A wide-angle camera is positioned at the rear of the vehicle and displays an image inside the car on an LCD (Liquid Crystal Display) screen to assist the driver. Benefits of rear vision cameras: Provides additional vision to assist the driver in manoeuvring. Is it a standard or optional feature? Rear-vision cameras are an optional extra on many new cars. Installation: Rear-vision cameras are generally factory-fitted, although retro-fitting is often possible. Cost: Approximately $1,500 for a factory-fitted device. 9