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ABSTRACT
Improvement of vehicle safety performance is one of the targets of ITS development. A pre-crash safety system has been developed that utilizes ITS technologies. The Pre-crash Safety system reduces collision injury by estimating TTC(time-to- collision) to preemptively activate safety devices, which consist of “Pre-crash Seatbelt” system and “Pre-crash Brake Assist” system. The key technology of these systems is a “Pre-crash Sensor” to detect obstacles and estimate TTC. In this paper, the Pre-crash Sensor is presented. The Pre-crash Sensor uses millimeter-wave radar to detect preceding vehicles, oncoming vehicles, roadside objects, etc. on the road ahead. Furthermore, by using a phased array system as a vehicle radar for the first time, a compact electronically scanned millimeter-wave radar with high recognition performance has been achieved. With respect to the obstacle determination algorithm, a crash determination algorithm has been newly developed, taking into account estimation of the direction of advance of the vehicle, in addition to the distance, relative speed and direction of the object.
1. INTRODUCTION
Many researches and developments have been conducted to meet society’s needs for safer vehicles. Particularly, occupant protection systems such as airbags, developed and introduced in order to reduce occupant injuries in crashes, are currently installed in most vehicles, making significant contributions to safety. Meanwhile, many studies have been made into the development of active safety technologies that help to avoid crash accidents. Unfortunately, however, the current situation is that active safety technologies are not sufficiently spread. Adaptive cruise control (ACC) has been commercialized since 1995, but its primary use has been convenience, not active safety.
Some audible warning systems and other systems are also being offered, but have not yet reached widespread use. Toyota Motor Corporation has explored the possibility of producing an active safety system employing Intelligent Transport Systems (ITS) technologies, through participation in the Advanced Safety Vehicle (ASV) Project, started in 1991 and led by the Ministry of Land, Infrastructure and Transport (Ministry of Transport at that time). [1]-[5] Critical basic ITS technologies for application to ASV include a surround monitoring sensor and an obstacle determination algorithm, which combines information from the surround monitoring sensor with other information to identify obstacles with which the vehicle is likely to actually crash. The sensor and crash determination algorithm for an active safety system should be capable of reliably determining unavoidable crashes, that is, reliably predicting a crash before it actually occurs, as well as reliably determining that a crash will not occur in a non-crash situation. Advanced technologies are required to make these predictions and judgements correctly while also taking into account the driver’s operation and behavior, and this has hampered widespread of active safety systems. Pre-crash safety (PCS) system has been developed, which operates only when it is judged that a crash cannot be avoided by most drivers under normal driving conditions. Determining unavoidable crashes is restricted to a short time period immediately before the crash, so as to improve the reliability of the judgement. In addition, the pre-crash safety system is made with a mechanism and system that will not place the driver and the running vehicle in an unsafe condition, even if the system is operated unnecessarily (i.e., when the system operates even though a crash may not actually happen). As a result, the world’s first commercial system has been achieved. This paper describes a pre-crash sensor for determining unavoidable crashes, which is a key technology in establishing the systems described above.
2. PRE-CRASH SAFETY SYSTEM
The system configuration of the pre-crash safety system is shown in Figures 1 and 2. The developed system consists of a pre-crash sensor, a pre-crash seat belt (PSB), and a pre-crash brake assist (PBA)
Vehicle-to-vehicle communication (V2V communication)
Vehicle-to-vehicle communication (V2V communication) is the wireless transmission of data between motor vehicles.
The goal of V2V communication is to prevent accidents by allowing vehicles in transit to send position and speed data to one another over an ad hocmesh network
Depending upon how the technology is implemented, the vehicle's driver may simply receive a warning should there be a risk of an accident or the vehicle itself may take preemptive actions such as braking to slow down.
V2V communication is expected to be more effective than current automotive original equipment manufacturer (OEM) embedded systems for lane departure, adaptive cruise control, blind spot detection, rear parking sonar and backup camera because V2V technology enables an ubiquitous 360-degree awareness of surrounding threats. V2V communication is part of the growing trend towards pervasive computing, a concept known as the Internet of Things (IoT).
In the United States, V2V is an important part of the intelligent transport system (ITS), a concept that is being sponsored by the United States Department of Transportation (DOT) and the National Highway Traffic Safety Administration (NHTSA). An intelligent transport system will use the data from vehicle-to-vehicle communication to improve traffic management by allowing vehicles to also communicate with roadside infrastructure such as traffic lights and signs. The technology could become mandatory in the not-too-distant future and help put driverless-cars on highways across America.
The implementation of V2V communication and an intelligent transport system currently has three major roadblocks: the need for automotive manufacturers to agree upon standards, data privacy concerns and funding. As of this writing it is unclear whether creation and maintenance of the supporting network would be publicly or privately funded. Automotive manufacturers working on ITS and V2V include GM, BMW, Audi, Daimler and Volvo.
V2V communications can help drivers avoid crashes on busy streets
Another major innovation that is bound to reshape the future of driving is vehicle-to-vehicle (V2V) communication. This technology is supposed to help drivers get accurate information on weather conditions and road hazards in real time, so that they can choose alternative routes and avoid traffic jams. Additionally, cars can inform other cars when they are about to make a turn, and let other cars know how fast they are moving, in order to allow drivers to adjust their speed accordingly and help them maintain a safe following distance at all times. Vehicle-to-vehicle communication technology will definitely be of great help to drivers, as it will help improve traffic flow, and increase highway safety. The NHTSA has announced that it will require all new vehicles to be equipped with this technology in the near future.
Land Rover Debuts Invisible Car Technology
Land Rover reveals Transparent Bonnet virtual imaging concept
New level of driver awareness with a 'see-through' augmented reality view of the terrain ahead, making the front of the car 'virtually' invisible from inside the cabin
Technology provides full visibility of what is underneath and in front of the car, with total clarity of otherwise hidden obstacles
Transparent Bonnet is part of a suite of new concept technologies to be showcased in Land Rover's Discovery Vision Concept car at the New York International Motor Show
Pioneering technology is being developed to give Land Rover drivers a digital vision of the terrain ahead by making the front of the car 'virtually' invisible.
Cameras located in the vehicle's grille capture data used to feed a Head-Up Display, effectively creating a 'see-through' view of the terrain through the bonnet and engine bay, breaking new ground in visual driver assistance. The technology, named Transparent Bonnet by its creators, shows how advanced technology will take Land Rover's unrivalled capability to the next level.
The technology enables a driver climbing a steep incline or manoeuvring
in a confined space to see an augmented reality view capturing not only the terrain in front of the car but also the angle and position of the front wheels.
• In a parallel hybrid bicycle human and motor torques are mechanically coupled at the pedal or one of the wheels, e.g. using a hub motor, a roller pressing onto a tire, or a connection to a wheel using a transmission element. Most motorized bicycles, mopeds are of this type.[2]
• In a series hybrid bicycle (SHB) (a kind of chainless bicycle) the user pedals a generator, charging a battery or feeding the motor, which delivers all of the torque required. They are commercially available, being simple in theory and manufacturing.[3]
The first published prototype of an SHB is by Augustus Kinzel (US Patent 3'884'317) in 1975. In 1994 Bernie Macdonalds conceived the Electrilite[4] SHB with power electronics allowing regenerative braking and pedaling while stationary. In 1995 Thomas Muller designed and built a "FahrradmitelektromagnetischemAntrieb" for his 1995 diploma thesis. In 1996 Jürg Blatter and Andreas Fuchs of Berne University of Applied Sciences built an SHB and in 1998 modified a Leitra tricycle (European patent EP 1165188). Until 2005 they built several prototype SH tricycles and quadricycles.[5] In 1999 HaraldKutzke described an "active bicycle": the aim is to approach the ideal bicycle weighing nothing and having no drag by electronic compensation.
• A series hybrid electric-petroleum bicycle (SHEPB) is powered by pedals, batteries, a petrol generator, or plug-in charger - providing flexibility and range enhancements over electric-only bicycles.
A SHEPB prototype made by David Kitson in Australia[6] in 2014 used a lightweight brushless DC electric motor from an aerial drone and small hand-tool sized internal combustion engine, and a 3D printed drive system and lightweight housing, altogether weighing less than 4.5 kg. Active cooling keeps plastic parts from softening. The prototype uses a regular electric bicycle charge port
Heavy vehicles
Bus Rapid Transit of Metz, a diesel-electric hybrid driving system by Van Hool[7]
Hybrid power trains use diesel-electric or turbo-electric to power railway locomotives, buses, heavy goods vehicles, mobile hydraulic machinery, and ships. A diesel/turbine engine drives an electric generator or hydraulic pump, which powers electric/hydraulic motor(s) - strictly an electric/hydraulic transmission (not a hybrid), unless it can accept power from outside. With large vehicles conversion losses decrease, and the advantages in distributing power through wires or pipes rather than mechanical elements become more prominent, especially when powering multiple drives — e.g. driven wheels or propellers. Until recently most heavy vehicles had little secondary energy storage, e.g. batteries/hydraulic accumulators — excepting non-nuclear submarines, one of the oldest production hybrids, running on diesels while surfaced and batteries when submerged. Both series and parallel setups were used in WW2 submarines.