My first post at the arduino....
I am currently working on my 50cc inertia dyno, i want to add an brake controller to be able hold speed ad various values.
My dyno bench has allready installed an bakedisc/calipper, and i want to control brake with an BIG rc servo.
I am completly lost in PID PWM steering world an hope for some simple advices
It is already hall-switch mounted so i can use as rpm pickup (digital).
Does anyone have experience from similar projects?
THNX
Please tell what You have achieved, in the form of code, schematics and datasheet links for none trivial devices.
Maybe you want better motor speed/torque control instead of wearing out brake pads.
Are you going to want to measure the applied torque as well as apply it? Are eddy current brakes of an appropriate size not practical?
Have not achieved anything yet, trying to find better solution than potensiometer and servo combined with lcd display.
Brake pads wear is fine, it will only be short runs maybe max 2 min.
Brakedisk from Bmw x5 and brakecalipper from Toyota Landcruiser.
Don`t need measure brake force now, maybe in the future...
It is inertia dyno, measure power without loadcell.
A system for holding the speed at different positions is what i am looking for.
Pid? (or something else) to control different servo loads?
That rotating weight needs to be in a strong cage , I would think the brake disc will get very hot quickly and the caliper a lot of force to operate .. do some tests first !
Probably done 500 dyno runs, don't think about that, dyno works perfekt, can retard roller with brake in 150km/t in a few seconds.
Looking for help with making controller for brake for holding roller at different speeds.
You should , lot of energy in rotating stuff , the belts need looking at too , ok hurting yourself but not others .
To start you need some form of sensor to measure speed - eg inductive sensor looking at bolt heads on the disc hub .
Operating calliper is next problem
Really a Dyno to hold a constant speed would have a fan cooled heater bank and no mass to accelerate . Easier to control .
The rotating mass adds lag to your control loop making life hard
Constant speed = ! accelerating so no power measurement. The brake on an inertia dyne is to add load so you can measure higher power without changing the accelerated mass, not hold at fixed speed. You need to know the amount of static torque you have applied to the system.
How will a servo control a hydraulic brake caliper?
I want to hold rpm steady on roller so i can simulate longer dyno run.
So i can adjust moped/motorcycle over longer runs.
I can already measure power with inertia controller that is installed in my dyno.
No need for measure of brake force, maybe in later project, but for now only somthing so i can hold brake steady.
The servo can pull in brake lever that is already installed in my dyno.
Well, surely you understand that you can't measure power by the acceleration method if the speed is constant.
Show a drawing of the brake lever you want to control with a servo. That doesn't sound like much of a problem since you don't want to know how much static torque you are applying.
How much torque does the servo need to provide? Maybe a linear actuator would work better.
My lokal hobbystore have rc servo that can pull 75kg in stock, easy aksess is why i think rc servo.
That doesn't answer the question of how much do you actually require for your mechanical arrangement. Controlling the servo is a trivial problem once you have a servo that is powerful enough.
If you don't want to measure the torque required then just buy the most powerful servo you can and experiment.
