Collision avoidance system
A collision avoidance system, also known as a pre-crash system, forward collision warning system, or collision mitigation system, is an advanced driver-assistance system designed to prevent or reduce the severity of a collision. In its basic form, a forward collision warning system monitors a vehicle's speed, the speed of the vehicle in front of it, and the distance between the vehicles, so that it can provide a warning to the driver if the vehicles get too close, potentially helping to avoid a crash. Various technologies and sensors that are used include radar and sometimes laser and cameras to detect an imminent crash. GPS sensors can detect fixed dangers such as approaching stop signs through a location database. Pedestrian detection can also be a feature of these types of systems.
Collision avoidance systems range from widespread systems mandatory in some countries, such as automated emergency braking in the EU, agreements between carmakers and safety officials to make crash avoidance systems eventually standard, such as in the United States, to research projects including some manufacturer specific devices.
Similar systems exist in aviation and maritime.
Advanced emergency braking system (AEBS)
The World Forum for Harmonization of Vehicle Regulations defines AEBS. UN ECE Regulation 131 requires a system that can automatically detect a potential forward collision and activate the vehicle braking system to decelerate a vehicle to avoid or mitigate a collision. UN ECE regulation 152 says deceleration can be 5 meters per second squared.Once an impending collision is detected, these systems provide a warning to the driver. When the collision becomes imminent, they can take action autonomously without any driver input. Collision avoidance by braking is appropriate at low vehicle speeds, while collision avoidance by steering may be more appropriate at higher vehicle speeds if lanes are clear. Cars with collision avoidance may also be equipped with adaptive cruise control, using the same forward-looking sensors.
AEB differs from forward collision warning: FCW alerts the driver with a warning but does not by itself brake the vehicle.
According to Euro NCAP, AEB has three characteristics:
- Autonomous: the system acts independently of the driver to avoid or mitigate the accident.
- Emergency: the system will intervene only in a critical situation.
- Braking: the system tries to avoid the accident by applying the brakes.
A collision avoidance system by steering is a new concept. It is considered by some research projects. Collision avoidance system by steering has some limitations: over-dependence on lane markings, sensor limitations, and interaction between driver and system.
Emergency steering function
The emergency steering function, known as ESF, is an automated steering function that detects a potential collision and automatically activates the steering system for a limited duration to avoid or mitigate a collision.The emergency steering function for UNECE countries is described by regulation 79.
Automated lane keeping Systems
deal with avoiding some cases of collisions.ALKS defines some concepts:
Regulations
AEB and ALKS are each defined by one or several UN-ECE regulations.Requirements related to AEB are regulations 131 and 152.
Regulation 157 is related to ALKS.
Japan has required AEB since 2020 and ALKS since 2021. The European Union requires AEB since 2022 but did not define a date for ALKS.
Automobile manufacturers
Various vendors provide AEB components to automakers. The global automotive AEB system market consists of a few established companies that are manufacturers or suppliers of specialized AEB components or systems. For example, the main vendors for radar systems include Bosch, Delphi, Denso, Mobileye, TRW, and Continental. Automobile manufactures may describe the systems installed on their vehicles using different names to differentiate their marketing efforts. A particular automaker may have systems and sensors sourced from a variety of suppliers. Therefore, even a single car brand may offer various levels of technology sophistication and the: frequency of false alerts can be different from model to model and trim level to trim level, depending on the types of camera and/or laser-based systems installed.In countries, such as the UK, one-quarter of new vehicles might have some kind of AEB system; but only 1% of previously sold cars might have AEB.
Audi
"Pre sense" autonomous emergency braking system uses twin radar and monocular camera sensors and was introduced in 2010 on the 2011 Audi A8."Pre sense plus" works in four phases. The system first provides warning of an impending accident, activating hazard warning lights, closing windows and sunroof, and pre-tensioning front seat belts. The warning is followed by light braking to get the driver's attention. The third phase initiates autonomous partial braking at a rate of. The fourth phase increases braking to followed by automatic full braking power, roughly half a second before projected impact. "Pre sense rear", is designed to reduce the consequences of rear-end collisions. The sunroof and windows are closed and seat belts are prepared for impact. The seats are moved forward to protect the car's occupants. 2015 introduced the "avoidance assistant" system that intervenes in the steering to help the driver avoid an obstacle. If an accident occurs, the "turning assistant" monitors opposing traffic when turning left at low speeds. In critical situations, it stops the car. "Multi collision brake assist" uses controlled braking maneuvers during the accident to aid the driver. Both systems were introduced on the Second generation Q7.
BMW
In 2012 BMW introduced two systems on the 7 Series. "Active Protection" detects imminent accidents by pretensioning safety belts, closes windows and moonroof, brings the backrest of the front passenger seat to an upright position, and activates post-crash braking. A driver drowsiness detection includes advice to take a break from driving. An "Active Driving Assistant" combines lane departure warning, pedestrian protection, and city collision mitigation.In 2013, "Driving Assistant Plus" was introduced on most models combining the front-facing camera, lane-departure warning, and in some cases front radar sensors to detect vehicles ahead. Should the driver not react to the warning of a potential collision, the system would gradually prime brake pressure and applywith maximum deceleration powerif necessary. In the case of a crash, the system can bring the vehicle to a standstill. Later iterations of the system on cars equipped with an Automatic Cruise Control system are improved by combining radar and camera detection during fog, rain, and other situations where normal camera operations may be compromised.
Ford
Beginning on the 2012 Ford Focus, Active City Stop was offered on the range-topping Titanium model, under the optional Sports Executive Pack. The system used windscreen-mounted cameras, radars, and lidars to monitor the road ahead. The system doesn't provide a warning, rather, it can prevent a crash from occurring at speeds between. This speed was later raised to and was available on all models, the Trend, Sport, Titanium, ST, and RS.General Motors
' collision alert system was introduced in GMC Terrain SUVs in 2012. It uses a camera to provide a warning when there is a vehicle ahead or there is a lane departure.The 2014 Chevrolet Impala received the radar- and camera-based crash imminent braking (radar technology detects a possible crash threat and alerts the driver. If the driver does not appear to react quickly enough or doesn't react at all, this feature intervenes to apply the brakes to avoid the crash. Forward collision alert, lane departure warning, side blind zone alert (using radar sensors on both sides of the vehicle, the system "looks" for other vehicles in the blind zone areas of the Impala and indicates their presence with LED-lit symbols in the outside mirrors. Rear cross-traffic alert features.
Honda
2003: Honda introduced autonomous braking front collision avoidance system on the Inspire and later in Acura, using a radar-based system to monitor the situation ahead and provide brake assistance if the driver reacts with insufficient force on the brake pedal after a warning in the instrument cluster and a tightening of the seat belts. The Honda system was the first production system to provide automatic braking.The system also incorporated an "E-Pretensioner", which worked in conjunction with the CMBS system with electric motors on the seat belts. When activated, the CMBS has three warning stages. The first warning stage includes audible and visual warnings to brake. If ignored, the second stage would include the E-Pretensioner's tugging on the shoulder portion of the seat belt two to three times as an additional tactile warning to the driver to take action. The third stage, in which the CMBS predicts that a collision is unavoidable, includes full seat belt slack take-up by the E-Pretensioner for more effective seat belt protection and automatic application of the brakes to lessen the severity of the predicted crash. The E-Pretensioner would also work to reduce seat belt slack whenever the brakes are applied, and the brake assist system is activated.
2013: Honda introduced new driver-assistance system called Honda SENSING in 2014 Honda Legend, with the tagline, "Safety for Everyone". The system uses two types of sensors: a millimeter-wave radar in the front grille and a monocular camera on the windshield. These sensors detect pedestrians and other objects with improved accuracy. Enhanced data processing capabilities allow the system to recognize surroundings, driver intentions, and vehicle conditions, enabling collaborative control over braking and steering. The system now includes six new functions, such as the Pedestrian Collision Mitigation Steering System, and assists in vehicle speed, following distance, and lane keeping. Honda continues to evolve its driver-assistive technologies globally to enhance safety and comfort.
2020: Honda announced the flagship variation of Honda SENSING called, Honda SENSING Elite. The system was first introduced in the new Honda Legend Hybrid EX. This system uses 3D maps, GNSS data, and sensors to monitor the vehicle's surroundings and driver condition. It can control acceleration, braking, and steering for smooth driving and includes features like hands-off lane change assist and Traffic Jam Pilot for Level 3 automated driving, approved by Japan's Ministry of Land, Infrastructure, Transport, and Tourism.
A key feature of Honda SENSING Elite is the hands-off function, which assists in steering the vehicle when the driver has their hands off the wheel, supported by adaptive in-lane driving. This aids in maintaining lane position at a pre-set speed and keeping a proper following distance from the vehicle ahead. The system also includes active lane change assist with hands-off function, which executes lane changes when the driver activates the turn signal and adjusts the vehicle's speed accordingly.
2021: Honda introduced the Honda SENSING 360 system, enhancing the original with omnidirectional sensing. This system helps eliminate blind spots and reduce collisions by using five millimeter-wave radar units and a front camera. Key features include Front Cross Traffic Warning, which alerts drivers to approaching vehicles at intersections; Lane Change Collision Mitigation, which helps avoid collisions during lane changes; and Collision Mitigation Braking, which provides braking assistance at turns. It also features Adaptive Cruise Control with Cornering Speed Assist, adjusting speed during cornering for smoother navigation. The application of Honda SENSING 360 will begin in 2022, starting from China, with the first vehicle equipped with Honda SENSING 360 being the eleventh-generation Honda Accord and sixth-generation Honda CR-V.
2022: Honda updated the SENSING 360 system with new features including Advanced Lane Driving and Lane Change Assist with hands-off capability, a Driver Emergency Support System, and Exit Warning. These additions enhance existing features like collision mitigation braking and front cross traffic warning.
2023: Honda SENSING 360+ builds on existing Honda SENSING 360 by adding a driver monitoring camera and high-definition maps. This updated system aims to reduce accidents caused by driver health issues or errors. It features Advanced Lane Driving with hands-off capability, Active Lane Change Recommendation, Predictive Curve Departure Warning, and an Exit Warning. The system will debut with the Accord in China in 2024 and expand globally. It includes a Driver Emergency Support System that helps stop the vehicle if the driver becomes unresponsive and connects to the emergency call center for added safety.