Regulated power supply for DC motors?

[tsushant]

Hi, I am an Electronics engineering student and I am working on robotics project.
I am using 150W brushed DC motors with sabertooth motor driver to control them. I am trying to follow line without using line sensors. I am getting feedback from 3000 ppr wheel encoders. So, I calculate error from difference between count of encoders and using PID algorithm for correction.

The problem faced is whenever I set PID constants for robot when battery voltage is 24V, it works fine for some time but after few time, when eventually battery voltage drops to 21-21.5 volts, these constants don't work properly & I have to set constants again. What can be the solution for this problem? Can it be managed only using other software algorithms or do I have to find a hardware solution?

Should I provide some sort of regulation to motor power supply? I had designed and implemented a DC-DC switching regulator as supply for motor year ago which gave me good results with setting constants, but that was low power motor(required only 3A current). Now my total requirement is about 16A current so is it feasible to design such regulator?
Please help.
Thanks in advance.

 

[picgak]

A DC-DC converter is the solution to your problem it gives steady 24v from a range say 21v to 29v

 

[tsushant]

A DC-DC converter is the solution to your problem it gives steady 24v from a range say 21v to 29v

Are you suggesting some buck-boost regulator? I tried to implement regulator using LM25118 buck-boost controller. It would work properly for currents upto 10A. Designing a regulator for 16A looks like complex task to me as too many considerations for circuit design as well as layout considerations. I think it is mainly because the high current requirement and inductive load.

My further doubt is how people from industry deal with such problem? Do they really use a regulator while operating BLDC motor with battery.

If I have to use a DC-DC converter which topology should I prefer considering my high current requirement and inductive load?

 

[picgak]

Dc- Dc converter can be built around PWM chip SG3525 which is simple