Alarm mistrust in automobiles: how collision alarm reliability affects driving

Collision warning/collision avoidance (CW/CA) systems target a major crash type and their development is a major thrust of the Intelligent Vehicle Initiative. They are a natural extension of adaptive cruise control systems already available on many car models. Many CW/CA algorithms have recently been proposed but the existing literature mainly focuses on algorithm development. Evaluations of these algorithms have been usually based on subjective ratings. The main contribution of this paper is the utilization of a naturalistic driving data set for the evaluation of CW/CA algorithms. We first collect manual driving data from the ICCFOT project, then process the data by Kalman smoothing, and finally identify ‘threatening’ and ‘safe’ data sets according to vehicle brake inputs and vehicle range behavior. Five CW/CA algorithms published in the literature are evaluated against the identified data sets. The performance of these algorithms is determined through a performance metric commonly used in signal detecti...

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Evaluation of automotive forward collision warning and collision avoidance algorithms

In this research, brief survey of literature on current developments in the field of lateral and longitudinal control of autonomous vehicle motions. The paper categorizes the motions of vehicle to: car following, lane keeping, lane changing, subsequently, longitudinal control (brake and throttle), lateral control (steering) and integration of these controls for autonomous vehicles was investigated. Also different equipment and approaches to control of motions in each field was proposed.

A historical review on lateral and longitudinal control of autonomous vehicle motions

A driving/braking force manipulation control input of a k-th wheel, which denotes one or more specific wheels among a plurality of wheels of a vehicle, is determined such that a required condition concerning a relationship among a road surface reaction force that may act from a road surface on the k-th wheel on the basis of the detected values or estimated values of a side slip angle and a friction characteristic of the k-th wheel, a feedback control input related to the driving/braking force of the k-th wheel for bringing a difference between a state amount of the vehicle and a reference state amount close to zero, a driving/braking force feedforward control input based on a drive manipulated variable supplied by a driver of the vehicle, and a k-th wheel driving/braking force manipulation control input is satisfied. This arrangement makes it possible to properly control a motion of an actual vehicle to a desired motion while properly considering the characteristics of a road surface reaction force acting from a road surface on a wheel.

Vehicle Control Device

Significant effort has been made on designing user-acceptable driver assistance systems. To adapt to driver characteristics, this paper proposes a forward collision warning (FCW) algorithm that can adjust its warning thresholds in a real-time manner according to driver behavior changes, including both behavioral fluctuation and individual difference. This adaptive FCW algorithm overcomes the limit of traditional FCW with fixed risk evaluation models and fixed triggering thresholds by continuously monitoring driver braking behaviors in multiple lanes. A real-time identification algorithm for the warning thresholds is designed by using the recursive least squares method. Based on naturalistic experimental data, offline simulations show that this algorithm can match driver behavioral fluctuation and individual difference in long-time driving condition, and as time goes on, the adaptability to driver behavior is gradually improved, thus decreasing the false-alarm rate of FCW.

A Forward Collision Warning Algorithm With Adaptation to Driver Behaviors

RCAS (rear-end collision avoidance system) has been developed as a system of ASV (advanced safety vehicle). It is a driver assist system to avoid the rear-end collision by informing the distance headway. It also has automatic braking function in case of emergency and distance warning function to the trailing vehicle. This paper describes the outline of RCAS, techniques about the preceding vehicle recognition and collision potential hazard evaluation. And experimental results about distance headway warning and collision avoidance by automatic braking are reported.

Development of rear-end collision avoidance system

PROBLEM TO BE SOLVED: To start idling stop as early as possible upon initial start-up of an engine while preventing deterioration of a battery, thereby to improve idling stop performance. SOLUTION: By a first permission means of an idling stop control ECU 12, when it is detected that a charging current of the battery 2 is reduced to a first threshold value indicating a fully-charged state within a predetermined time period of the initial start-up of the engine, idling stop control is permitted, and thereafter, when it is detected that the battery 2 is reduced to a power storage amount of an allowable lower limit, the idling stop control is inhibited. By a second permission means of the idling stop control ECU 12, the first permission means is prioritized, and when it is detected that the charging current of the battery 2 is not reduced to the first threshold value after passage of the prescribed time period, and the charging current of the battery 2 is reduced to a second threshold value larger than the first threshold value, idling stop control is permitted even when the battery 2 is not in a fully-charged state, and thereafter, when it is detected that the battery 2 is in a discharging state of a second discharging amount less than a first discharging amount, the idling stop control is inhibited. COPYRIGHT: (C)2010,JPO&INPIT

Idling stop control device

PROBLEM TO BE SOLVED: To provide a following driving device and a control method therefor, capable of following deceleration of a leading car with high responsibility and accuracy, and keeping a prescribed distance between cars. SOLUTION: An ECU estimates acceleration/deceleration speed of the leading car using a Kalman filter, obtains an estimated acceleration/deceleration speed a (S1), and finds an estimated distance between cars based on the estimated acceleration/deceleration speed a to determine an estimated error which is a gap between the estimated distance between cars and an actual distance between cars (S2). When the self car is judged to be a first condition (estimated delay condition) corresponding to changes or the like of the acceleration/ deceleration speed of the leading car based on the estimated error (YES of S3), a target acceleration/deceleration speed Gr is calculated by computing a (1) formula (S4), and when it is judged to be converted to a second condition escaping from the first condition (NO of S3, YES of S5), the target acceleration/ deceleration speed Gr is calculated by computing a (2) formula (S6) to complete a subsequent motion. COPYRIGHT: (C)2004,JPO

Following driving device and control method therefor

PROBLEM TO BE SOLVED: To automatically and positively perform idling-control of an automobile. SOLUTION: Based on the change of the between-vehicle distance and the speed of own vehicle, detected by a periphery recognizing sensor 1 and a speed sensor 2, an ECU 7 derives the relative speed of a preceding vehicle relative to the own vehicle, and compares the derived relative speed with the speed of the own vehicle to judge whether the preceding vehicle is stopped or started. When it is judged from output of the speed sensor 2 that the own vehicle is stopped in a state of the preceding vehicle judged to be stopped, an engine control part 8 stops as engine of the own vehicle to automatically stop idling. After the engine-stop, when it is judged by the ECU 7 that the preceding vehicle is started, the engine control part 8 restarts the engine of the own vehicle to automatically start idling.

Hideo Araki

Papers

Development of rear-end collision avoidance system

Idling stop control device

Development of rear-end collision avoidance system

Following driving device and control method therefor

Idle control device