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[SKATEway]Post 6

Hello,

This 3 days I essentially worked on the diagram bloc to self balance our board with a null angle to the horizontal.

Its a simple PID but we have to add some stuff to make the regulation working. First we need to prevent the wind up on the integrator when the output is satured. Then the D componet increase hight frequencies noise. So we attach a low pass filter. FinaLly we have the value to apply on the motor. The board move to an other angle. Perturbations can emerge. Like the ground slope, the wind or humans. We got the final position now. We need accelerometer and gyroscope output to calculate the new angle of the board to the horizontal. We can directly use the output of the accelerometer but we have to apply an anti drift filter to the gyroscope output to cancel the integrated error over the time. Then we compare the request angle with this angle and do the operation again.

Here, the diagram bloc !

Charles

 

[SKATEway]Post 4

Hello,

This week we got a scolding for our teachers because we have not worked a lot so far. We have to stand up and move on.

Now we have to concretize the choice of sensors and study about the regulation of the system.

On my side I will study about regulation. We already know we will use a closed loop because the output feedback on the system. Learn what is already existing. Chose several algotithm PID, SS, SIMO, MIMO, RST, LQR. Then determine the number of instruction to estimate the worst execution time of the loop, and the system’s response.

I know PID is the simple but not the more efficient, to be seen.

Determine what is the input of the regulation, an angle (not necessarly null), a speed. Think wich angle will we use. Absolute horizontal or about the road.

Charles