PID Controllers for Water Levels

First step START THE PUMP!!!

Please give more background information (when is the homework due?)

actually wat i wanna do is to create a water level control system.. a bit like a water plant system.

my thinking is, use PID to control the water flow.. and use PLC or Matlab to do the overall system and display..

am i in the right way?

No need for all that.

Level control in a tank is easy: get rid of the tank.

It would depend on how accurately you need to control it. For simple control where your level will vary a little depending on input and output flow rates, a simple float valve would do the job. (proportional only control)

If you need it to control at set point all the time you will need to introduce integral and this will need a more complex system. You will need a sensor, a controller, and a final control element (usually a control valve) to create a feedback loop.

You will only need derivative if the tank is large or the flow is small

PID level control on a tank is unneccessary. Consider the humble toilet flush cistern. Any of the following:

• Ballcock
• Portsmouth valve
• Torbeck valve
• etc.

may be found inside it. Their function is to return the level to the setpoint after it has been lowered.

The whole purpose of a tank is to allow the level to go up and down. If one doesn't want to do that, then the tank is unneccessary.

I plan to do without any hardware.. i will more to software..