Introduction to Motor Control

The general p.i.d control is as follows

(dutycycle)=(dutycycle)p + (dutycycle)i + (dutycycle)d

p. Control (proportional control): The output is proportional to the input error signal, that is, the error is corrected in a fixed proportion, but the system will have a steady-state error.

i. Control (integral control): When the system enters a steady state and there is a steady-state error, the error is integrated with time. Even if the error is small, it can increase with time, so that the steady-state error is reduced to zero.

d. Control (differential control): When the system is overcoming the error, its change always lags behind the error change, indicating that the system has large inertial components or (and) lag components. Derivative is the trend of prediction error change in order to prevent the controlled variable from overshooting seriously.

Motor drive protection measures

There are also protective measures for the driver. When the load is too large or improperly used, it will cause a large current and burn the power transistor. In order to protect the driver from being damaged due to the current exceeding the specification, it is generally used to increase the withstand current of the power transistor or to increase the current sensor as protection. Secondly, when the motor load is not small, the energy and overvoltage sent back to the driver by the motor end will endanger the driver when it stops rotating. This can be prevented by combining with the overvoltage protection circuit and the regenerative energy dissipation circuit. Other hall-sensors are normal or not will also affect the correctness of pwm control, which can be judged by the control department and warned in time.