Adaptive Cruise Control
3.1 Introduction
Adaptive Cruise Control (ACC) is one of the ADAS systems, introduced by General Motors in 1990 that is similar to conventional cruise control. ACC assists the driver to keep a safe distance from preceding vehicle by controlling the engine, throttle and brake.
Figure 3.1.1: Prabs, (2010), Adaptive Cruise Control system
As shown in the above Figure 3.1.1. ACC uses a forward-looking radar sensor, which is installed behind the front grill of the vehicle. The Adaptive cruise control equipped vehicle has the ability to detect the speed and distance of the predecessor vehicle or any other obstacle ahead. Adaptive cruise control automatically adjusts the car speed initially set by the driver …show more content…
Firstly, the driver has to select the desired speed and the distance that has to be maintained from the vehicle ahead. This distance can be set at several levels adapting to the driving situation and individual driving styles. After setting, ACC will get activated.
A long-range radar sensor in ACC, will monitors the driving situations ahead of the vehicle. The sensor transmits the radar waves that are reflected by the object in front of the vehicles. Based on the data, ACC can detect the preceding vehicle and can calculate the distance and relative speed of the vehicle ahead.
When the system detects that it is approaching a vehicle, it interacts with engine control or electronic stability program and ensure that the safe distance is maintained. Once the road ahead is clear, ACC automatically accelerates the vehicle to the preset or desired …show more content…
PID based Adaptive cruise control Algorithm:
The Proposed method is used to determine the distance and speed by using the PID Controller. Following steps explains how to determine the distance and speed of the preceding vehicle:
Start of the ACC system
Step1: Starting the Engine.
Step2: User will run the vehicle manually by using the acceleration and brake pedal.
Step3: User will check if the ACC is turned on or not.
Step4: If ACC is turned off then it directly goes to step2.
Step5: On the other hand, If the ACC is turned ON then it checks whether any object detection is get fails or not.
Step6: Then if object detection gets fail then we have to bypass the method to PID Controller as seen in Figure 3.5.2.
Step7: After that it again checks if any object detection fails or not.
Step8: If there was no object detected then the host vehicle speed is equal to the set speed.
Step9: After, if the object gets detected, we calculate the distance by measuring the time difference techniques.
Step10: Getting the vehicle speed.
Step11: we need to fix up the vehicle speed is equal to the lead vehicle