Influences of weather phenomena on automotive laser radar systems

Abstract

Abstract. Laser radar (lidar) sensors provide outstanding angular resolution along with highly accurate range measurements and thus they were proposed as a part of a high performance perception system for advanced driver assistant functions. Based on optical signal transmission and reception, laser radar systems are influenced by weather phenomena. This work provides an overview on the different physical principles responsible for laser radar signal disturbance and theoretical investigations for estimation of their influence. Finally, the transmission models are applied for signal generation in a newly developed laser radar target simulator providing – to our knowledge – worldwide first HIL test capability for automotive laser radar systems.

Data fusion of radar and stereo vision for detection and tracking of moving objects

“…Backscatter from weather phenomena such as rain, fog, dust or snow may result in unwanted detections [16]. Lighting conditions may also hinder reliable detection, e.g.…”

“…Before digital processing, the received signal is mixed down to an intermediate frequency (IF). After some manipulation, and assuming that high frequency terms are filtered out, the IF signal for the n th pulse is given by 16) where τ is the time-of-flight to the target and back, and c is the speed of propagation. It can be shown that the dominant frequency components in the mixed down IF signal are due to the time-of-flight and the Doppler shift induced by relative radial motion between the radar and the reflector.…”

“…Recall that, in the GIW-PHD formulation, the uncertainty in these two entities are modelled by a Gaussian and inverse Wishart distribution respectively. Observations acquired after data fusion are in the WRF, allowing a linear measurement model of the form 16) where σ x , σ y , and σ z are the standard deviations in the x, y, and z directions respectively. Mathematically, the measurement set of sets passed to Equation (6.48) at time k is of the form Z fusion,k = {Z…”

Event-triggered autonomous platoon control against probabilistic sensor and actuator failures

“…To guarantee string stability and maintain the desired space, much research has been proposed in [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. As stated in [6], there have been two control strategies, i.e.…”

“…However, these control methods suggested are not applicable to the APCS. Second, without considering the contingent failures might happen to the onboard sensors in practical cars for reasons such as poor visibility due to rain or sandstorm and interference of radar signals [16,17]. The combined actuator fault is the third aspect that may add to the limitations since the actuator failure will cause a wrong operation on the actuator speed growing or reducing.…”