Hi everyone, what would be the best way to create a model of a quadrotor in MuJoCo? The main question is probably how to create actuators simulating thrusters? Could you provide an example? Thanks a lot!
Are we talking about a spinning propeller, or a rocket-style thruster? For a thruster, you can attach a motor to a free joint, and specify the 6D gear parameters so that the motor applies force along the desired axis. If you want a spinning propeller, you need to use the lift-drag force simulation in MuJoCo. Attached is an XML illustrating this.
Thanks a lot for the help. I first tried to make a simple thruster model. I am creating a site at the location of the thruster and then I am specifying the site for the actuator (motor type). As a gear parameter, I set gear='0 0 100 0 0 0' to see the effect of forces only. If I understand the first 3 components will be responsible for scaling the force, and the next 3 the torque. Is that correct? The documentation also says that the force will be generated in the site's frame ( http://mujoco.org/book/modeling.html#general ). But a simple simulation with generating a force at a single thruster does not seem to produce an adequate behavior since a force on a single thruster should have just flipped the quadrotor. Thus, I am wondering if I did it correctly? I also have another question: - what is the simplest way to simulate opposite direction torques along the yaw (z) axis generated by thrusters. I am attaching the xml file I have created and recording of the experiment I see. Looking forward to your response!