A Kalman filtering fuzzy logic algorithm for recognition of lane departure

In all kinds of traffic accidents, the unconscious departure of the vehicle from the lane is one of the most important reasons leading to the occurrence of these accidents. In view of the specific problem of lane departure, a lane departure decision-making method is established without calibration relying on the Kalman filtering fuzzy logic algorithm, according to the characteristics of expressway lanes, based on the machine vision and hearing fusion analysis of lane departure, integrating the extraction of the linear lane line model and the region of interest (ROI) in this paper to judge the degree of vehicle departure from the lane by integrating the slope values of the 2 lane lines in the road image. The results show that the system has good lane recognition capabilities and accurate departure decision-making capabilities, and meet the lane departure warning requirements in the expressway environment.

Caching Behaviour in the Gray Jay and the Source-Departure Decision for Rate-Maximizing Scatterhoarders

We developed a model that concerns, in part, how long a scatterhoarder should persist in caching food from an ephemeral, locally abundant source ('bonanza') before moving on in search of other sources. The model assumes that an animal scattering food caches for later use behaves in a manner that maximizes the rate at which it stores recoverable (surviving) food in its habitat. It is shown theoretically that under some conditions it is better not to cache all available food but instead to move on in search of other food sources. This 'source-departure decision' for scatterhoarders is analogous to the patch-departure decision for animals that forage among food patches. It is shown that whether, and at what point, a 'moving-on threshold' is reached should depend on the size of the source, the strength of density-dependent cache theft, and the abundance of sources in the habitat. A field experiment was performed to test the qualitative prediction that gray jays, Perisoreus canadensis, should not persist as long in caching food when a day-long opportunity for caching is restricted to a single source (single-source treatment) as when such an opportunity is divided among a series of disjunct sources (multiple-source treatment). In the single-source treatment, jays tended to cache at lower overall rates, transport food items to more distant cache sites, and spend less time caching. These tendencies became more pronounced later in the day. However, although the rate of caching approached zero in the single-source treatment, the jays did not completely cease caching. This apparent violation of the model is attributed to the behaviour of recaching, a facet of gray jay scatterhoarding behaviour that was not built into the model. This retrieval and redistribution of previous caches resulted in the stabilization of the density of caches near the source. In addition, this switch from single- to multiple-load caching trips arguably would make it economical for gray jays to continue to make caching trips from a source beyond the source-departure point predicted by the model. Our theoretical and empirical results begin to show how scatterhoarders may behave in a manner that maximizes the long-term average rate of storage of recoverable food energy throughout their habitat.

The flight directionality of honeybees foraging on real and artificial inflorescences

An examination of the flight directionality, the change in direction between arrival and departure, of Apis mellifera (Apidae) workers foraging on artificial inflorescences and on inflorescences of Echinops sphaerocephalus L. (Compositae) is reported. Thirty-seven circular, artificial inflorescences, each with three feeding tubes separated by 120° located on the perimeter were used. At the beginning of each visit all tubes contained 2 ± 0.2 μL of 1.2 M sucrose solution. Bees locating the tubes would probe one or more of them, then depart to another artificial inflorescence and repeat the foraging sequence. Changes in flight directionality were generated during within-inflorescence locomotion and not after feeding had ceased. Directionalities of bees that circled a second time around these inflorescences were indistinguishable from bees departing the same locations prior to completing a single cycle. Hence, the directionality of bees visiting tubes in the sequence 1-2-3-1, 1-2-3-1-2, or 1-2-3-1-2-3 were indistinguishable from the directionality of bees visiting tubes in the sequence 1, 1-2, or 1-2-3, respectively. The direction faced by bees while probing the final tube or floret (last-faced direction) was most often the departure direction; thereafter, bees flew ahead to the nearest inflorescence. An energetic analysis of the artificial inflorescence study showed that directionality was independent of nectar uptake rates. The experiment using real inflorescences, some of which had been enriched with ca. 10 μL of 1.2 M sucrose solution, confirmed that directionality was generated during within-inflorescence locomotion and that the last-faced directon was the most frequent departure direction; furthermore, changes between the last-faced and departure directions were independent of nectar uptake. Evident in the search pattern of honeybees were the following: (i) a forward-moving tendency while on inflorescences, (ii) a departure decision, (iii) departure in the last-faced direction, and (iv) minimum deviation from the last-faced direction when flying directly to the next inflorescence. Although bees tend to move in a forward-facing direction during all movement phases, the floral architecture facilitates or induces turning. The extent of the turn is limited by the bees decision to depart. It is concluded that directionality is an epiphenomenon resulting from interactions among floral architecture, bee locomotion, floral nectar content, and the bee's departure decision. Memory of the arrival direction is not required.