Page - 16 - in Integration of Advanced Driver Assistance Systems on Full-Vehicle Level - Parametrization of an Adaptive Cruise Control System Based on Test Drives

2. Adaptive Cruise Control 1A 2A (a) (b) δ δ 1ϕ 2ϕ 1ε 2ε Figure 2.8.: (a) Signals received by Tx1 and Tx2 and (b) error signal of eq. (2.8), (a) and (b) forϕ1<ϕ2, both adapted from [Mah88] Assuming that d r (fig. 2.7), the difference between the two signals reads r2−r1 = d sin(ϕ). Thisdifference in lengthresults inaphaseshift∆δ= 2pidλ sin(ϕ)of thereceived signals. Using this expression and eq. (2.9), the azimuth angle can be calculated by ϕ= arcsin [ λ pi d arctan (∣∣∣∣∆∑∣∣∣∣)]. (2.10) Scanning RADAR Scanning RADAR sensors sweep a narrow RADAR beam over the FOV. Figure 2.9(a) shows an illustration for one object atϕi. The lower graph shows the received powerP for different discrete angles. The maximum of the power is received at azimuth angleϕi of the object, [Win09]. A mechanical or an electrical mechanism can be used to deflect the RADAR beam. Multi-Beam RADAR InMulti-Beam RADAR sensors, thedeviceemitsanumberoffixedbeams. Figure2.9(b) gives an example of a RADAR sensor with two beams, Tx1 and Tx2. Using the received powerP of every antenna and the antenna diagram, the azimuth angleϕi of the object can be found, [Win09]. 16