**6.7 Adaptive cruise control (ACC)**

This system was introduced firstly inside Japan, and then in Europe for the car market. ACC systems are based on a front looking sensor designed with laser radar, (LIDAR) or microwave radar with a maximum detection range of around 100 m. The microwave radar sensor operates in the 76–77 GHz bands that have been reserved for application of automotive obstacle detection. Based on front vehicle information, mainly distance and speed, the ACC system regulates own vehicle speed by acting on engine control and braking system. The ACC is an extension of the standard Cruise.

Control system, with the extra capability to adapt the speed of the vehicle to the speed of the preceding one. This function was firstly introduced in Japan on 1995 based on LIDAR technology.

Europe experienced the emergence of lidar and microwave technology in the following years which led the introduction of these technologies in the Mercedes car during the year 1999. It is noteworthy to mention that the automatic cruise control system (ACC) was seen fitted with truck manufactured by Mercedes automobile industry. Presently around twenty automobile manufacturers are producing this type car and truck.

It is based on a high performance GNSS/INS for dynamic applications developed on the convenience of a conventional cruise control system by automatically changing speed to match the vehicular flow in front. It's important to determine precisely when and how the system intervenes, how well it acquires and then it tracks the targets and how it performs in a number of different real-world scenarios [6]. Measurements such as target bearing, distance, relative velocity and time-tocollision are key to the evaluation of these systems. Sensors with RT and RT range for ACC offers the following characteristics:


In order to get accurate vehicle-to-vehicle measurements, an RT inertial navigation system and RT-Range S [7] are installed in the vehicle under test (VUT) and any target vehicles. An RT inertial navigation takes into account a number of parameters for operation. These include position with respect to latitude, longitude, altitude distance and its coordinate position. Besides the position of these, velocity, acceleration, orientation, angular rates and acceleration and slip angle are also taken into account. RT-XLAN Wi-Fi radios then send real-time information from target vehicles back to the VUT where the RT-Range S calculates, logs and outputs real- time measurements about the relative position of the target vehicles. The measurements being the output include the position of both the Hunter and target vehicles, orientation and velocity. The current status of the ACC hardware can also be logged with the data via a CAN bus interface, which is a robust vehicle bus standard designed to allow microcontrollers and devices to communicate with each other in applications without a host computer. It can also be or later synchronized with the measurements via a GPS time stamp. Moreover, from some manufacturers, ACC is given in combination with lane warning system.

It will have frequency allocation for 24 GHz sensors. The properties of various sensors associated with the functioning this ACC are presented in **Table 7** as under:

### **6.8 ACC/stop & go**

Adaptive cruise control (ACC) permits a driver to travel with the flow in traffic. In this situation, a radar sensor monitors the situation in front of the vehicle. As the road is observed to be clear, ACC operates with the desired speed. If the radar sensor finds a slower vehicle ahead of it, ACC automatically maintains and adjusts the speed a preset distance. In the Stop & Go version, the system results in slowing the car down in a traffic jam, or even comes to a halt it completely. If the car has an automatic transmission, Stop & Go also restarts the engine once traffic gets moving again after a brief pause.

### **6.9 Stop & go**

In this system the driver continues to receive support from this sensor with respect longitudinal control for the formation of queue. During the stop & go of the vehicle facing the front side, longitudinal control is carried out by the system for detecting the near side objects.

**231**

*Driver Assistance Technologies*

**Sensor Property**

**6.10 Lane keeping assistant**

**Table 7.**

structure, the HMI becomes more important.

• Axes to be in ISO 8855:1991 orientation

• Vehicle edge to lane edge measurements

lane markings when any intervention is triggered.

• Longitudinal speed to 0.1 km/h

• Update rate at least 100 Hz

• Position to 0.03 m

• Yaw velocity to 0.1°/s

• Acceleration to 0.1 m/s2

helps to lane keeping assistance to adhere to lane driving.

The Protocol accuracy requirements [12] for this are as under:

• Time is required as a synchronization DGPS (Differential GPS)

For the LSS (Lane support System) LKA tests, the key measurements are the distance between the outer-edge bulge of the front tires and the inside edge of the

The function of a lane keeping assistant system includes the lane detection and the feedback to the driver if he is leaving a defined trajectory within the lane. Lane departure warning systems merely alert the driver when the car is leaving its lane, while lane-keeping assist actually works to keep the car from moving out of the lane. An active steering wheel can help the driver with a force feedback to keep on this trajectory. The lane is detected by a video image processing system. Additionally to the lane departure warning aspects especially regarding the infra-

Smallest object: Metal bar 10 mm diam (vertically placed at 1,5 m)

Frequency: 24.125 Ghz Distance range: 10 m Velocity range: 60 m/s Field of view:

The driver gets all assistance through his touch with steering and other devices for taking decisions for the vehicular movement linking with the controller that also

*DOI: http://dx.doi.org/10.5772/intechopen.94354*

LIDAR Wavelength l: 850 nm Radar Frequency: 76–77 GHz

> Range: 1 to 200 m Resolution: 100 cm Search Area: 12°

• ± 50 0Horizontal • ± 0,5 m/s Accuracy:

*Available sensors with their properties in ACC (source: Ref No. [12]).*

0.2 km/h

• ± 0,05 m • ± 0,5 m/s

Speed measurement precision: <

Angular Precision: < 0.3°

Dimensions: 90 x 40 x 15 mm


**Table 7.**

*Models and Technologies for Smart, Sustainable and Safe Transportation Systems*

for ACC offers the following characteristics:

• Real-time birds eye view showing measurements

ACC is given in combination with lane warning system.

• Ability to track multiple objects in real-time

• Perfectly suited to open-road testing

• Relative accuracy 2 cm

• Heading accuracy 0.1°

It is based on a high performance GNSS/INS for dynamic applications developed on the convenience of a conventional cruise control system by automatically changing speed to match the vehicular flow in front. It's important to determine precisely when and how the system intervenes, how well it acquires and then it tracks the targets and how it performs in a number of different real-world scenarios [6]. Measurements such as target bearing, distance, relative velocity and time-tocollision are key to the evaluation of these systems. Sensors with RT and RT range

In order to get accurate vehicle-to-vehicle measurements, an RT inertial navigation system and RT-Range S [7] are installed in the vehicle under test (VUT) and any target vehicles. An RT inertial navigation takes into account a number of parameters for operation. These include position with respect to latitude, longitude, altitude distance and its coordinate position. Besides the position of these, velocity, acceleration, orientation, angular rates and acceleration and slip angle are also taken into account. RT-XLAN Wi-Fi radios then send real-time information from target vehicles back to the VUT where the RT-Range S calculates, logs and outputs real- time measurements about the relative position of the target vehicles. The measurements being the output include the position of both the Hunter and target vehicles, orientation and velocity. The current status of the ACC hardware can also be logged with the data via a CAN bus interface, which is a robust vehicle bus standard designed to allow microcontrollers and devices to communicate with each other in applications without a host computer. It can also be or later synchronized with the measurements via a GPS time stamp. Moreover, from some manufacturers,

It will have frequency allocation for 24 GHz sensors. The properties of various sensors associated with the functioning this ACC are presented in **Table 7** as under:

Adaptive cruise control (ACC) permits a driver to travel with the flow in traffic. In this situation, a radar sensor monitors the situation in front of the vehicle. As the road is observed to be clear, ACC operates with the desired speed. If the radar sensor finds a slower vehicle ahead of it, ACC automatically maintains and adjusts the speed a preset distance. In the Stop & Go version, the system results in slowing the car down in a traffic jam, or even comes to a halt it completely. If the car has an automatic transmission, Stop & Go also restarts the engine once traffic gets moving again after a brief pause.

In this system the driver continues to receive support from this sensor with respect longitudinal control for the formation of queue. During the stop & go of the vehicle facing the front side, longitudinal control is carried out by the system for

**230**

**6.8 ACC/stop & go**

**6.9 Stop & go**

detecting the near side objects.

*Available sensors with their properties in ACC (source: Ref No. [12]).*
