10-04-2017, 08:29 PM
A basic motor controller consists of the basic units such as the processor, h-bridge circuit, the motor and the encoder. The encoder provides a closed loop feedback unit providing the feedback to the processor about the speed output of the motor.
PID Closed loop control system:
Here, the PID controls the gain of the closed loop control system.several characteristics of the feedback are considered while adjusting the gain to the process. The feedback here is provided by the encoder which provides and output proportional to the speed of the motor.
The PID control system consists of the P-Gain, I-gain and D-gain given separately to the Summing unit and from there to the process. The process output is then summed and fed back as the input.
PID implementation
The basic questions addressed here are
What is the mathematics of PID? , how to program it, what are the common problems and how to tune the PID behavior. The different PID variables are the Error term, the proportional gain P, the Integral gain I and the derivative gain D. The Error term is obtained subtracting the the feedback (motor speed) from the set point (set speed). Here the error is measured in the units of the encoder counts per unit time. Proportional term is obtained by multiplying a coefficient Kp with the error term. This term provides linear response to the error term .
Get the report here:
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The following links may also be useful:
http://ee.sharif.edu/ industrialcontrol/PID_Example_DC_Motor_Speed_Control.pdf
http://seattleroboticsencoder/200205/pidmc.html