Hey guys, as I’ve posted here somewhat earlier before I plan on building a quadruped robot. A bit about me; I’m 17 and from Germany and currently en route to finishing my Abitur in Mechantronics (something somewhat in between high school and a college degree) I’ve worked a lot with CAD and Python in the past but I plan on running this robot with MATLAB, which I still need to learn. I’ve already purchased some of the components required, but still need to save up for a MATLAB students license, so I couldn’t run simulations on my model as was suggested to me by /u/AgAero in my other post in this sub.
I came up with a pretty solid 3D CAD Model of it, which should be very easy to 3D print, but I do still have some parts about it which I don’t quite like yet, so I plan on doing a redesign of it. And with that redesign would come my question.
Is it smarter for a quadrupedal robot to have its center of mass higher up or lower down than the plane of the hip actuators/ joints?
I’ve seen a bunch of robots use either way and get along with it quite fine. As for example, OpenDog by James Bruton has its center of mass somewhat lower than for example ANYmal by ETH and ANYbotics. Should I leave the center of mass so high up top and trust that the guys at ETH and Boston Dynamics know what they’re doing? What is the reasoning for that robot topology? Can anyone hook me up with resources and materials concerning that? What is still iffy and or even wrong with my (not so strictly) planned robot topology? Can you provide me with resources where I can learn more about such things?
If you’re interested in the CAD model I came up with here’s a quick photo of it (some things are still broken and the weird double sonar upfront is just for the cool CAD looks, as the cards are super modular I could just as easily have one sonar up front and one on the back)
The Motors are MG996Rs with a Torque of about 11.2kg/cm at 7.2V, which I can deliver with my “”PSU”” at the back of the Robot. The robot is powered with a NiMH battery and is not supposed to run for extended periods of time. Absolute Peak power should be less than 30W. The maths and controls should be done by an Arduino Due. There is a 6-Axis IMU (MPU6050) onboard as well as some Bluetooth connectivity to hook the robot up to my laptop. Total weight is less than 2KG and the size (L x W x H) is about 270x260x290mm. The Robot is divided into two parts: Basically a lower half including the legs and battery and an upper “rack” in which cards are inserted with the wanted components, as this should yield me a lot of flexibility.
I would be absolutely stoked on feedback and criticism but do keep in mind that this project is still in its pre-beta phase.
I hope that my question is not too far stretched and that I can gather more insights into robotics as I did with my last post. Cheers and greetings from Germany!