leesp
Mechanical
- Apr 23, 2015
- 1
I am a control engineer, and I want to measure the Frequency Response Function (FRF) of my plant.
Basically, the plant is a motor-driven linear mechanism, ie. a linear carriage is moved by a PMDC motor through timing belt and pulley.
I understand that in practice, normally the auto- and cross- power spectrum method is used (H1, or H2)
The questions are:
1. What signal should I excite the plant (motor) input? White noise? But the motor would barely move with pure white noise
2. Should I excite the plant (motor) with only a specific speed profile (e.g trapezoidal profile)? Or should the excitation signal be (trapezoidal profile + white noise)?
Assumption is that there is no undesired noise (no measurement noise, no input noise due to surrounding, etc.)
Basically, the plant is a motor-driven linear mechanism, ie. a linear carriage is moved by a PMDC motor through timing belt and pulley.
I understand that in practice, normally the auto- and cross- power spectrum method is used (H1, or H2)
The questions are:
1. What signal should I excite the plant (motor) input? White noise? But the motor would barely move with pure white noise
2. Should I excite the plant (motor) with only a specific speed profile (e.g trapezoidal profile)? Or should the excitation signal be (trapezoidal profile + white noise)?
Assumption is that there is no undesired noise (no measurement noise, no input noise due to surrounding, etc.)