Progress Report Development of a Driver Alert System for Road Safety

Martin Gallagher 4 th Year Electronic Engineer

Today's Progress Report 1.Progress Completed to Date 1. Software 1.1Hough Transform 1.2Eye Detection Algorithms 2. Hardware 2.1Pressure Sensors 2.Outline of plans of work to be completed. 2.1Time Line

Software 1.1-Hough Transform Previously I had been using a Function by Kevin Chawke, to detect both eyes the transform had to be ran twice, the code relied on loop and this caused the function to be slow to implement for the purposes needed

Software Using a transform available on the Mathworks website I have been able to detect circular areas of interest in pictures and test video

Software The function works by: 1. Taking in a greyscale image 2. Building an accumulation array by calculating the “gradient” and “magnitude of gradient” of the pixels 3.Combining the results of the pixel voting with the array. The function also computes the local maxima and minima to find the centre of the circles and returns them as a Nx2 array called circen containing the X and Y co- ordinates respectively. Returned also are the radii of the circles in a Nx1 array called cirrad

Software 1.2Eye Detection Algorithm Once Circen and Cirrad have been returned there will usually be a surplus of circles detected. Filtering out these surplus due to geometric characteristics of eyes should yield a stable performance 1. The Iris should be the same or similar size 2. Eyes are a fixed distance apart 3. Angle between eyes and X plane should not be extremely great

Eye Detection Algorithm Shown is a sample of circles of 3 radii and in different locations. Applying the characteristics described

Pairing Circles of similar radius Pairing the circles of similar radii we see there are 7 pairs. 1,2 &3 are of radius 5 4 & 5 are of radius 7 and 6,7 & 8 are of radius 10

Excluding those outside distance range As the eyes are of a fixed distance apart and should only vary if the subject turns their heads. Pairs whose distance apart lies outside the max distance allowed are removed from the search.

Excluding those pairs at large angles If the driver is vigilant and conscious their eye level should be relatively flat and not of angles greater than 45°

Problems with software This picture shows both eyes being detected and are highlighted in blue. Lighting plays a major in the detection as shadow will cause error in the detection process

Solution Should only one eye be detected the transform will be applied to an area each side of the eye at lower threshold levels to compensate for shadow.

2.Hardware 2.1 Pressure Sensors These will be used to monitor the drivers grip on the steering wheel. They consist of 2 flexible substrates, with printed electrodes and semiconductor material sandwiching in a spacer substrate. Diagram from FSRguide

Pressure Sensors The conductance is plotted vs. force (the inverse of resistance 1/r).This format allows interpretation on a linear scale. For reference, the corresponding resistance values are also included on the right vertical axis. Diagram from FSRguide

Work to be completed The Majority of the Matlab code should be running and testing by the 24 th Jan- Running live video - The pick eyes function running - Sensor code implemented

Work to be completed 31 Jan -Combine all these data inputs into a testable programme. 21 Feb – Transfer some modules of the code onto a microprocessor.

Questions?