Application of the mathematical autodriver algorithm for autonomous vehicles

The mathematical theory for autonomous vehicles, which was initially developed for 4 Wheel steering vehicles was formulated to work for 2 wheel steering vehicles as well. This was the first step towards making the theory closer to practice. Then a sample road using clothoids as the transition curve was generated. Clothoid was used as the best transition curve according to the literature for mobile robots trajectory generation. This study ended up in development of a design chart which could be used for better road design. The sample road is used to find the kinematic steering angles required by the vehicle to stay on the road. The kinematic steering angles work well only at very low forward velocities. The dynamic differential equations of motion of the vehicle needed to be solved to make the study of motion of the vehicle possible in higher velocities. During high forward velocity travelling some factors will cause the vehicle to move on a road different to the desired path of motion. The sample road generated proved that the traditional method of solving differential equations of motion was not very effective especially in the case of complicated mathematical paths of motion. That is why a new method was sought for, which resulted in the generation of the Steady-State Dynamic Steering method. This method provides an alternative way of studying the dynamics of motion of a vehicle, which is proved to be much faster and less complicated than the traditional method. At the end the new method was, put in to test by trying different vehicle travelling manoeuvres. After validation of the new method it was used mathematically to take control of a car to travel a sample desired path of motion autonomously by using the mathematical theory of autonomous vehicles

A survey on the effect of Cochlodinium.sp bloom on shrimp culture complexes and hatcheries activities in Bushehr Province

The aims of this project was to inform and aware about the red tide condition before entering the algal bloomer in water resources to the hatcheries and farmed shrimp complexes in Bushehr province coastal. Field investigation and sampling have been carried out in the southern of the input water channels of Mond, Delvar and Helleh farmed shrimp complexes, which are located along the coastal of Bushehr Province, from April to December 2011 .The physic-chemical parameters such as pH, salinity and water temperature and also meteorological conditions were measured and recorded on the field. The water sampling has been lunched for determination of nutrients and chlorophyll - a, phyto- and zoo- planktons. No Cochlodinium.sp outbreaks have been detected in the studied area, during the study. The only bloom which reported by a fisherman, was outbreak in offshore of Bushehr province in Khoure Khan on 13th September 2011. The sample which transferred to the Iranian National Shrimp Research Institute was included Alexandrium.sp and its density was 2 million cells per liter. The identified phytoplanktons were belonged to three order of Bacillariophyceae (52.6%) with average density of 10778 cells per liter, Dinophyceae (37.7%) with density of 7731 cells per liter and Cyanophyceae (9.7%) with density of 1980 cells. 12 genera belonged to Dinophyceae , 25 genera of Bacillariophyceae and two genera of Cyanophyceae were observed during the study. The highest density of phytoplankton was recorded in Helleh station by 18374 cells per liter. The maximum density of phytoplankton was at Delvar station by 141120 cells per liter in December. The highest density of the phytoplanktons was belonged to Dinophyceae by 126000 by cells per liter of which the Alexandrium.sp had the density of 124500 cells per liter in August 2011. From the Dinophyceae the Alexandrium.sp with mean density of 20345 cells per liter, Ornithocercus 920 cells and Prorocentrum.sp 820 cells were the predominant species. The identified Zooplankton in were belonged to 8 branches and 19 groups. The highest density of zooplankton was recorded in Helleh station by 1194 no. per liter. Nauplii were the dominant zooplankton groups with an average density of 136.4 no. per liter, Tintinnids 98.7, Cyclopoida 60.8, Calanoida 35.7 and Harpacticoids 14.5 no. per liter . The average of water and air temperature was recorded 29.4 °C and 28.3 °C, respectively. Average of salinity was 41.2 and pH was 8.46. The average of depth in all stations was 5.7 m. The mean concentrations of silicate, nitrate, nitrite, ammonia and total phosphate were 1.99, 0.03, 0.009, 0.14 0.15 ppm, respectively and the average of chlorophyll - a was 0.94 mg.m-3

EEG Markers in Emotionally Unstable Personality Disorder-A Possible Outcome Measure for Neurofeedback: A Narrative Review.

Objectives. There is growing evidence for the use of biofeedback (BF) in affective disorders, dissocial personality disorder, and in children with histories of abuse. Electroencephalogram (EEG) markers could be used as neurofeedback in emotionally unstable personality disorder (EUPD) management especially for those at high risk of suicide when emotionally aroused. This narrative review investigates the evidence for EEG markers in EUPD. Methods. PRISMA guidelines were used to conduct a narrative review. A structured search method was developed and implemented in collaboration with an information specialist. Studies were identified via 3 electronic database searches of MEDLINE, Embase, and PsycINFO. A predesigned inclusion/exclusion criterion was applied to selected papers. A thematic analysis approach with 5 criteria was used. Results. From an initial long list of 5250 papers, 229 studies were identified and screened, of which 44 met at least 3 of the predesigned inclusion criteria. No research to date investigates EEG-based neurofeedback in EUPD. A number of different EEG biomarkers are identified but there is poor consistency between studies. Conclusions. The findings heterogeneity may be due to the disorder complexity and the variable EEG related parameters studied. An alternative explanation may be that there are a number of different neuromarkers, which could be clustered together with clinical symptomatology, to give new subdomains. Quantitative EEGs in particular may be helpful to identify more specific abnormalities. EEG standardization of neurofeedback protocols based on specific EEG abnormalities detected may facilitate targeted use of neurofeedback as an intervention in EUPD

Hydraulic engine mounts: a survey

An ideal engine mount should provide a dual behavior. It needs to be soft to reduce the transmitted force, and to be hard to limit the relative displacement. The constant parameter linear mounts are unable to provide a good isolation when the excitation frequency is variable. Hydraulic engine mounts were invented as smart isolators to passively produce a soft isolator at low amplitude and a hard isolator at high amplitude. Having a dual behavior puts the mounts in the domain of nonlinear systems which in turn causes many new phenomena which have never appeared in linear analysis. The dual behavior hydraulic engine mounts were introduced around 1980 and passed through many analytic and technical improvements. This article will review these improvements up to 2012 and discusses the technical problems and methods of remedy

Smart passive vibration isolation: requirements and unsolved problems

Vibration isolators are needed to control the relative displacement, acceleration, or most importantly the transmitted force to the base or to the isolated device. As a general rule, a good vibration isolator should be as soft as possible to reduce the transmitted force, and it should be hard to limit the relative displacement. Soft suspension provides large relative displacement in resonance zone. To limit the relative displacement while having a soft suspension, a limiting displacement design is needed. There are two practical designs, Hydraulic Engine Mount (HEM) and Piecewise Linear Suspension (PLS) which are being used in industry since 80s. Hydraulic engine mounts were invented to passively produce a low damping at low amplitude and a high damping at high amplitude. Similarly, piecewise linear suspension were introduced to provide a soft suspension at low amplitude and a hard suspension at high amplitude. Having dual behavior puts both HEM and PLS in the domain of nonlinear system which in turn brings many new phenomena never appeared in linear analysis. This article will review the necessity of having a dual behavior suspension and the design of the two practical designs. However, both of these designs have some challenging and unsolved problems. Introducing the problems opens avenue for supervisors, researchers, and students to direct their research practice and hopefully solve them

Better road design for autonomous vehicles using clothoids

During the project for generating a mathematical algorithm for autonomous vehicles, a sample road which included different turns and scenarios was required. Studying different types of roads and their line equations Euler spirals, also known as Clothoids were found to be the best solution for designing new roads suitable for autonomous vehicles. During 19th century Arthur Talbot derived the equation of Clothoids to be used as an easement curve for the purpose of avoiding shock and disagreeable lurch of trains, due to instant change of direction. The Euler Spiral is a curve whose degree-of-curve increases directly with the distance along the curve from the start point of the spiral. This provides a linear change in the steering angle required by the driver to go through the turn. In other words for a car traveling on a Clothoid transition road curve there is no need for sudden changes in the steering angle of the wheels. The angle required starts from zero and increases to a maximum value and goes back to zero linearly. This provides a very comfortable ride for the passengers of the vehicle. The use of these curves for road design have been investigated, and a design chart have been proposed to be used for finding the best suitable transition curve for different applications

Sustainable flat ride suspension design

It was suggested [1] that having natural frequency of the front approximately 80 % of that of the rear suspension in a vehicle will result in a flat ride for the passengers. Flat Ride in this case means that the pitch motion of the vehicle, generated by riding over a bump for instance will fade in to the bounce motion of the vehicle much faster. Bounce motion of the vehicle in mush easier to tolerate and feels more comfortable for the passengers. In a previous study the authors, analytically proved that this situation is not practical. In other words, for any vehicle there will only be one certain velocity, depending on the geometry and suspension system specifications which the flat ride will happen at. The search continued to find a practical method for enjoying the flat ride in vehicles. Solving the equation of motion of the vehicle for different spring rates and road configuration the authors came up with design chart for smart suspension systems. Using the advantages of the analytical approach to the flat ride problem, the chart was established to be used for vehicles with smart active suspension systems. In this paper the mathematical methods used and the resulted criteria for designing a flat ride suspension system which will perform in different speeds is presented

Vehicle flat ride dynamics

By modelling a four-wheel vehicle as a bicycle, it has been suggested (Olley 1934) that if the radius of gyration, r, in pitch is equal to the multiplication of the distance from the center of gravity of the front, a, and rear, b, wheels of the car (r2 ¼ a _ b), the bounce center of the vehicle will be located at one spring and the pitch center on the other spring of a bicycle car model. Employing the flat ride condition, r2 ¼ a _ b, the system of the sprung masses of a vehicle can be considered as two separate mass-spring systems. Therefore, front and rear suspensions may be modelled as two separate one degree of freedom spring-mass system. This paper mathematically derives the flat ride condition and clarifies analytically how exact is the suggested condition