Today's automotive cyber-physical systems for autonomous driving aim to enhance driving safety by replacing the uncertainties posed by human drivers with standard procedures of automated systems. However, the accuracy of in-vehicle perception systems may significantly vary under different operational conditions (e.g., fog density, light condition, etc.) and consequently degrade the reliability of autonomous driving. A perception system for autonomous driving must be carefully validated with an extremely large dataset collected under all possible operational conditions in order to ensure its robustness. The aforementioned dataset required for validation, however, is expensive or even impossible to acquire in practice, since most operational corners rarely occur in a real-world environment. In this paper, we propose to generate synthetic datasets at a variety of operational corners by using a parameterized cycle-consistent generative adversarial network (PCGAN) . The proposed PCGAN is able to learn from an image dataset recorded at real-world operational conditions with only a few samples at corners and synthesize a large dataset at a given operational corner. By taking STOP sign detection as an example, our numerical experiments demonstrate that the proposed approach is able to generate high-quality synthetic datasets to facilitate accurate validation.

In this article, a novel asymptotic probability evaluation (APE) method is proposed to estimate the probability of correlated rare failure events for complex integrated systems containing a large number of replicated cells. The key idea is to approximate the failure rate of the entire system by solving a set of nonlinear equations derived from a general analytical model. An error refinement method based on look-up table is further developed to improve numerical stability and, hence, reduce estimation error. Furthermore, a statistical algorithm based on resampling is developed to accurately estimate the confidence interval of APE. Our numerical experiments demonstrate that compared to the state-of-the-art method, APE can reduce the estimation error by up to$30\times $without increasing the computational cost.

In this article, a novel asymptotic probability approximation (APA) method is proposed to estimate the overall rare probability of correlated failure events for complex circuits containing a large number of replicated cells (e.g., SRAM bit-cells). The key idea of APA is to approximate the overall circuit failure rate based on a set of carefully defined failure events. An efficient hierarchical subset simulation (H-SUS) method is developed to calculate the aforementioned failure rate and a statistical methodology is further proposed to estimate the confidence interval of APA. Our numerical experiments demonstrate that APA can accurately and reliably estimate the overall failure rate of correlated rare failure events involving more than 20 000 independent random variables.

Today's automotive vehicles are often equipped with powerful data processing systems for driver assistance and/or autonomous driving. To meet the rigorous safety standard, one critical task is to ensure extremely small failure rate over all possible operation conditions. Such a validation task requires a large amount of on-road testing data to cover all possible corners. In this paper, we describe a novel general-purpose methodology to synthetically and efficiently generate a broad spectrum of corner cases for validation purpose. Our proposed method is based upon cycle-consistent generative adversarial networks (CycleGANs) trained by a small set of image samples to mathematically map a nominal case to other corner cases. By taking STOP sign detection as an example, our numerical experiments demonstrate that the proposed approach is able to reduce the validation error by up to 100× given a limited data set for corner cases.

In this paper, a novel Asymptotic Probability Estimation (APE) method is proposed to estimate the probability of correlated rare failure events for complex integrated systems containing a large number of replicated cells. The key idea is to approximate the failure rate of the entire system by solving a set of nonlinear equations derived from a general analytical model. An error refinement method based on Look-up Table (LUT) is further developed to improve numerical stability and, hence, reduce estimation error. Our numerical experiments demonstrate that compared to the state-of-the-art method, APE can reduce the estimation error by up to 45x without increasing the computational cost.

We describe a novel methodology to validate vision-based autonomous driving systems over different circuit corners with consideration of temperature variation and circuit aging. The proposed work is motivated by the fact that low-level circuit implementation may have a significant impact on system performance, even though such effects have not been appropriately taken into account today. Our approach seamlessly integrates the image data recorded under nominal conditions with comprehensive statistical circuit models to synthetically generate the critical corner cases for which an autonomous driving system is likely to fail. As such, a given automotive system can be robustly validated for these worst-case scenarios that cannot be easily captured by physical experiments.

In this paper, a novel Asymptotic Probability Approximation (APA) method is proposed to estimate the overall rare probability of correlated failure events for complex circuits containing a large number of replicated cells (e.g., SRAM bit-cells). The key idea of APA is to approximate the overall circuit failure rate based on a set of carefully defined failure events. An efficient Hierarchal Subset Simulation (H-SUS) method is developed to calculate the aforementioned failure rate and a statistical methodology is further proposed to estimate the confidence interval of APA. Our numerical experiments demonstrate that APA can accurately and reliably estimates the overall failure rate of correlated rare failure events involving more than 20,000 independent random variables.

Efficient performance modeling is an extremely important task for yield analysis and design optimization of analog circuits. In this paper, a novel regression modeling method based on hierarchical shrinkage priors is proposed to construct hybrid performance models with both high accuracy and low computational cost. In particular, the user-defined model templates derived from design equations and the general-purpose orthogonal polynomials are combined together to set up a hybrid dictionary. Next, in order to avoid over-shrinking large model coefficients, a novel regression method based on hierarchical shrinkage priors and variational Bayesian inference is adopted for model fitting. A rail-to-rail operational amplifier example demonstrates that the proposed method achieves up to 40% error reduction over other state-of-the-art approaches without increasing the modeling cost.