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Project 9 Traffic F low Simulation. Team 5. Content s. Introduction & Motivation Environment Modeling (Roadways) Simulation Statistics Visualization Conclusion. Introduction. Real-time image processing and Robotics for automotive applications
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Contents • Introduction & Motivation • Environment Modeling (Roadways) • Simulation • Statistics • Visualization • Conclusion
Introduction • Real-time image processing and Robotics for automotive applications • Driver assistance using Intelligent feedback on traffic conditions, cross-roads accidents, etc. • Collision warning and avoidance system • Intelligent parking assistance
Environment Modeling- Roadways • Preparing the map The map is stored in a text file • It is represented by: • Lines • Curves
Representing lines • ( x1, y1, z1 ) -> ( x2, y2, z2 ) line 125 400 10 125 375 20
Representing curves • ( x, y, z, r, anglestart, anglestop, direction) arc 125 300 20 75 270 180 -1
Sampling • Sampling distance • Line • length of line • number of sampling points • allocating the points • Curve • angle • length of arc • number of sampling points • angle of sampling points • allocating the points
Simulation of Car Traffic Flow • Based on physics laws (kinematics) • The control parameters: • the number of cars • the size of the histogram interval (for generating statistics) • Equations • the velocity law: • the position law:
The parameters of the cars • Position on the road: index and lane • Current speed and cruising speed • Maximum acceleration • Maximum deceleration • Reaction time of the driver
How the simulation works • The time is divided into small intervals (~ 10ms) • In one time slice a car can only: • maintain speed • accelerate • decelerate
The algorithm • for each car • must decelerate ? • yes: decelerate ! • no: current speed < cruising speed & can accelerate ? • yes: accelerate ! • no: maintain speed.
When the car must decelerate ? • We search for the cars in front of the current car • When the cars in front of the current car are close together (20m), they block the road. • We assume that in the next time-slice the cars in front will maintain speed (a reasonable assumption) • After that, we check if we maintain the speed of the current car, the time distance between cars will be decreasedbelow the time_dist (a constant value).
The car can accelerate? • a car can accelerate when the time distance to the car in front is less than the time_distanceor when an overtake is performed (not yet implemented) • the maximum allowed acceleration is the greatest between the maximum possible acceleration of the car and the acceleration that will not lower the time distance under time_distance
Acceleration and Deceleration • We update the position and the velocity:
Utilization of road • Dividing the road to smaller intervals • Counting the number of cars on each interval -> histogram • Drawing a chartminimal, average, maximal utilization
3D Visualization • Actually a 2.5D representation • It can be rotated and zoomed in and out • Still to do more !!