Hello Everybody !!
I am currently working on motion control circuits and need to control a linear actuator from Firgelli Automations(firgelliauto.com/product_…roducts_id=187) which operates at 12V DC,upto 10 A current at full load .It has internal build in limiting switch.For motion control,i don’t have to use a microcontroller,instead i could use an analog (op amp ) based PID controller to control the linear actuator using H-bridge.Linear actuator is equipped with LVDT to sense the linear displacement of the actuator and the output is fed to the error amplifier. I have with me analog devices LVDT signal conditioner to get the output voltage to be feedbacked to the input.
Reference signal is 0 to 5 volt varying voltage signal given by user.
Could anyone help me with the circuit of PID or a rough idea to how to do the whole thing mostly with the PID control and H- Bridge drive.
Would be thankful to you guys.
Regards
Ankan
A proportional–integral–derivative (PID) controller is a control algorithm and can be implemented regardless of the type of actuator or controller you use.
You can certainly implement the controller in an analog way (i.e. by not using any microcontrollers) by building analog integrators, derivation and a proportional gain (using mainly capacitors, inductors and op amps). The advantage of such a method would be obtaining a really fast response (much faster than the actuator needs) and it should be very cheap in components.
The disadvantages of such approach are the utter lack of flexibility, since all algorithm the parameters depend on the values of the components. Also, unless you use some fancy op amp arrangements, the performance will be dependant on many environmental factors such as temperature, humidity, etc.
Regardless of the approach you use, the main challenge would be to select the proper gains for each controller stage in order to achieve e the performance you are looking for.
