I have an electro-hydraulic drive – a hydraulic motor with coupled to it a synchronous generator. Also there is an encoder installed on the shaft of the generator. By using my DAQ unit I will measure its position, speed and acceleration. The most important aspect for me right now is how I can measure the drive’s inertia and be as precise as possible.
I now that Torque = Inertia * Acc. Acceleration can be measured by the DAQ. But what to do with the drive’s torque? I can agree that the hydraulic motor’s torque can be calculated (I know pressure, displacement and its efficiency). There is no electrical connection of the generator to an exciter or means, so it is literally only extra load on the motor’s shaft. In this case I am just wondering, can I actually use the motor's torque as the drive's torque (motor plus generator).
So in this case, I can use the derived motor’s torque and measured acceleration in order to calculate the inertia? Is something wrong with my approach or?