Cognitive Safety Integration takes safety to new levels

By combining active and passive safety technologies with electronics and sensing capabilities, TRW is creating intelligent systems that help to enhance the safety of drivers, pedestrians and passengers.

Cognitive safety integration warns drivers, actively assists to help them avoid danger and intervenes to lessen the impact of an accident – or helps to avoid one altogether. High levels of integration are also key: enhanced vehicle control technologies; car-to-car and car-to-infrastructure communication systems; and occupant/pedestrian protection developments.

Clear view of the environment

The basic integrated technologies include environmental sensors such as radar and video cameras that provide clear images of the environment surrounding the vehicle. Knowing exactly what is happening near the vehicle at any moment in time is essential to establishing cognitive safety functions, while sensor data fusion allows systems to react autonomously.

A major target for TRW is to use synergies and systems acting in an intelligent way to achieve higher levels of road safety. To this end, TRW has taken a building-block approach to cognitive safety that includes: a wide range of sensors and fusion of the data they provide; integrated functionality; and smart actuators.

Pedestrian detection

When vehicles collide with pedestrians, there is a high risk for serious injury or death. According to statistics provided by National Highway Traffic Association and the Insurance Institute for Highway Safety, both in the USA, a pedestrian has an 85 percent chance of dying when involved in a motor vehicle collision at 40 mph (64 kph), a 45 percent chance at 30 mph (48 kph), and a 5 percent chance at 20 mph (32 kph). Clearly, an active pedestrian safety system that warns a driver of a potential collision, and automatically decreases the speed of the vehicle to mitigate, or even avoid, the collision, has significant potential to help  improve survival rates.

TRW Automotive is developing such a system by fusing the sensory information from the 24 GHz AC100 radar and the company’s scalable camera (S-Cam). In addition to vehicle detection, lane detection and traffic sign recognition, the scalable camera is capable of detecting and tracking pedestrians at distances of over 40 m, even in challenging urban scenarios.

If a pedestrian is detected, sophisticated risk assessment algorithms are employed to determine the probability of a collision by taking into account the predicted paths of the vehicle and the pedestrian. Then a warning is issued, or a braking maneuver is initiated, with the aim of slowing the vehicle and reducing the severity of the impact. To reduce false collision warnings and false collision mitigation braking events, a second confirmation of a critical collision trajectory with the pedestrian is required by radar.

TRW is working with its customers to help them understand how to prepare for the new Euro NCAP active safety ratings.  The new rating system increases the importance of pedestrian detection and protection.

Lateral support

Unintended departures from a lane or the roadway due to driver distraction or drowsiness account for a significant proportion of accidents. Lane departure warning systems (LDW) are therefore widely considered to make highly effective contributions to road safety.

TRW’s lane keeping assist system (LKA) goes a step further. It not only issues a warning signal, but generates a corrective steering torque which is transmitted to the electric power steering (EPS) controller via the CAN bus. The EPS controller checks the steering torque demand for plausibility and applies it to the steering system. Thus, an unintended lane departure could  be prevented without any active driver input. Of course, the corrective steering torque can be easily overridden by the driver at any time. Since the LDW system is not meant for autonomous driving, the system continuously monitors the forces applied to the steering wheel and is de-activated after a few seconds should the driver take his hands off the steering wheel. Typically, LKA becomes available at speeds of 60 kph (37 mph) and above.

Meanwhile, a second generation video sensor developed by TRW is capable of distinguishing between lane markings of different colors. The sensor was first launched in April 2011 as part of an enhanced LKA system developed for a Korean vehicle manufacturer. This LKA system provides a particularly smooth steering torque intervention by feeding back the steering system response into the LKA controller.

While LDW and LKA are safety systems that become active only when a driver loses control of his vehicle due to distraction or drowsiness, a lane guidance (LG) system continuously helps the driver to stay in his lane. This is achieved by a closed loop cascade controller which determines the corrective steering torque. It processes not only the video sensor information and the steering system response, but also vehicle state information provided by the vehicle stability control system.

Although the system provides a seamless co-existence between ’LG in control’ and ‘driver in control’ states of vehicle steering, it obeys the same rules as LKA: it can easily be overridden by the driver at any time and it is de-activated after a few seconds should the driver take his hands off the steering wheel.

TRW’s LG system is designed to operate in the speed range, 60 kph (37 mph) to 170 kph (105 mph). The system is not yet in production, but its performance has been demonstrated successfully in test vehicles equipped with column drive EPS and rack drive EPS.

Potential to revolutionize vehicle safety

Advanced thinking, the development of new components and electronic integration, supported by powerful algorithms, has the potential to take vehicle safety from evolutionary to revolutionary status in the coming years. The scope and potential to bring new safety technologies to market on both vehicles and the highway infrastructure is limited only by commercial, legal and cost considerations. As is always the case with advanced, new, automotive systems, leading edge developments will first find their way on high end vehicles, cascading down into mass produced cars in the following years.