Position control of DC motor in simple pendulum: The joint block will not accept output torque from motor?

I am attempting to control (via PID) the position of a simple pendulum driven by a DC motor, in Sumulink/Simscape. The first image below is the the set-up for the pendulum, and the follow up image is the inside of the "DC Motor" block.

Right now, the idea is to have a target, or reference, position of 45degrees. I then use the summing junction to produce the error signal and input that into the PID block. The compensator then sends a signal to the DC motor. I believe I have wired the motor correctly such that it simply takes a voltage from the controlled voltage source block and, in theory, should produce a torque - also letting me measure the current draw along the way. The torque from the DC motor is then fed into the joint block, which is set to accept an input torque. However, Simulink will not allow me to connect the two blocks together. I believe I have made the the right signal type (Simulink signal vs physical signal), and it should just be a torque value. Am I missing something? I believe I have the right set up but this is mu first time working with electronics blocks.

Answer 1

[Franck Donnadieu]

Hello, you should Try to put a torque sensor between the DC Motor and the entry "T" of your joint.