Here is my heuristic algorithm for applying manifold topology to system dynamics, control engineering, and (I think) robotics in general.
For each "moving part" in the dynamical system, we have a copy of SE(3)=R3⋊SO(3)(=Qfree in Bullo and Lewis's notation). For N moving parts, we have N copies of SE(3), SE(3)N. The process for creating this is somewhat automated by Denavit-Hartenberg tables:
(The graphic is from this video series https://www.youtube.com/watch?v=4Y1_y9DI_Hw&list=PLZaGkBteQK3HQFSWDM7-yRQWTd86DeDIY&index=1)
We then have interconnections between the moving parts, which leads to an n dimensional submanifold of SE(3)N, Qn, called the configuration space of the dynamical system.
This configuration space has a Riemannian metric g it inherits as a submanifold of SE(3)N. The Riemannian metric, g, then has a canonical lift ˜g to the tangent bundle, TQ, of Q, as outlined in do Carmo, for instance. With this lift of the Riemannian metric, we have a musical isomorphism between TQ and T∗Q, the co-tangent bundle. Now, the co-tangent bundle is naturally a symplectic manifold, with canonical symplectic from ω. Corresponding to ˜g and ω, we have a canonical almost complex structure J on TQ (and/or T∗Q?), completing the canonical compatible triple, (˜g,ω,J), on (say) TQ.
Next, in a coordinate patch on TQ, we have a Lagrangian function L. We may then have a non-conservative force field acting additionally on the mechanical system, which we model as a differential 1-form F. This lead to the system of first-order differential equations {ddt{∂L∂˙q1}−∂L∂q1=F1…ddt{∂L∂˙qn}−∂L∂qn=Fn Now, this system may have a critical point (q,˙q). At this critical point, we can take the Jacobian matrix A of the Lagrangian vector field/differential 1-form. This then becomes the plant function for a control engineering problem. The matrix A should have 2n eigenvalues; because of a hypertechnical consideration, we will suppose none of them are purely imaginary, so the Hartman-Groβman Theorem applies. We then place a control feedback loop with proportional control gain matrix K given as in this diagram.
We then use the gain matrix K to place 2n−2 of the eigenvalues of the closed-loop system to have real part between, say, -5 and -10 in the complex plane, then place the remaining two eigenvalues -- called the dominant eigenvalues or the dominant poles of the closed-loop system -- to have real part between, say, -2 and 0 and to satisfy the design requirements of the control engineering problem specifications.
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