What are digital pid position control algorithm and incremental type control algorithm? Try to compare their advantages and disadvantages

(1) digital PID position-based control algorithm:

Since the computer output u(k) can directly control the actuator (such as valves), the value of u(k) and the position of the actuator (such as the valve opening) is a one-to-one correspondence, it is usually referred to as the formula for the positional PID control algorithm.

Disadvantages: each output is related to the past state, the calculation of e(k) to be accumulated, computer arithmetic workload.

(2) digital PID incremental control algorithm:

The actuator needs to be the increment of the control amount (such as driving a stepper motor) when the output of the digital controller is only the increment of the control amount, the formula is called incremental PID control algorithm.

Advantages: ① small impact in the event of malfunction, if necessary, the method of logical judgment can be used to remove the error data.

②Small impact when switching manually/automatically, easy to realize non-disturbance switching. When the computer fails, the original value can still be maintained.

③There is no need to accumulate in the arithmetic formula.

Disadvantages: large integral truncation effect, there is a steady state error; the impact of overflow is large.