Linearising a electromechanical control system with Motor, Gear box with stiffness and PWM contoller

Hello Matlab Experts,

I am trying to model a position control problem with simulink simscape components. The following components are used. 1. PI(s),H Bridge , controlled PWM , a comparator to generate a direction for H bridge, DC motor, Gear box, and spring representing gear box stiffness and a load as inertia ,inertia of the order of 10e6 kg*m^2, and suitable PS-S and S-PS blocks and a ideal rotational reference sensor.

2. When i try to simulate the system the system works and tracks the input with few SS error and with small oscillation. Now i am required to tune the system using PID tunning.

As i understood prior to tuning of the plant I am required to linearize the plant and the only i can apply automated PID Tuning.

I tried the linearization of the plant with system identification using simulutated I/O in the PID tunning tool box. During this i observed the instead of tracking step command the output continuously increase like a ramp. Can any one help to solve the issue ?

Regards Prima Rodrigues

Answer 1

[Arkadiy Turevskiy]

Please try to follow this example which is very similar to the workflow you are trying to use. If you run into the issues, please provide a clear and detailed explanation of what specifically is not working.

[Prima rodrigues]

Hello.. I attached to plots one with simulation result with P=1 and I=1 and running simulation for 40 sec( tried upto 200 sec) , the observation is that output is trying to track the input value of 0.01 degree , but during the system identification the output looks like a ramp and not settling , the figure pid.png show system identification GUI. Any clue for solving the issue?

Thanks & Regards Prima Rodrigues

[Prima rodrigues]

Hello, I am trying to obtain the tf of the plant using bode linear analysis plot using simulink.The obtained tf have very high frequency poles and zeros which is not desirable. Could u suggest to extract the tf of the simulink model for a given frequency range say 0.01 to 1000 Hz.I am tried with bounds option available in bode but it didn't solve the problm Thanks Prima.R