| Topic for open discussion: Passive
Dynamic Stability of AWES
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| November 4, 2020, post by Dave Santos Passive vs. Active AWES Stability & Control Derivatives Preface from Wikipedia on Nov. 4, 2020: Stability derivatives Stability derivative vs. control derivative
====Stability derivatives and control derivatives are related because they both are measures of forces and moments on a vehicle as other parameters change. Often the words are used together and abbreviated in the term "S&C derivatives." They differ in that stability derivatives measure the effects of changes in flight conditions while control derivatives measure effects of changes in the control surface positions: Stability derivative measures how much change occurs in a force or moment acting on the vehicle when there is a small change in a flight condition parameter such as angle of attack, airspeed, altitude, etc. (Such parameters are called "states".) Control derivative measures how much change occurs in a force or moment acting on the vehicle when there is a small change in the deflection of a control surface such as the ailerons, elevator, and rudder. Looping Foil Under Lifter Kite Generates Electricity
Many AWES engineers neglect Passive Stability design factors, even making a priori claims that Active Control is essential. This is a fallacy. Properly engineered AWES with Inherent (dynamic) Stability can reduce or completely avoid dependence on active control. Active Control can be reserved for emergency supervisory "kill" of large-scale AWES. A major advantage of many-connected AWES Topological Stability is robust Limit Cycles. Active Control AWES are subject to higher control-error, actuation-saturation, part-failure rates, power-loss, and/or excess mass. Here is a 2012-2020 kPower AWES existence proof of TRL9 COTS kites rigged as an all-modes Passive Automation, based on 100% inherent Passive Dynamic Stability derivatives, with no Active Control derivatives. ============= Kite Network Topological Control
Extending
"S & C Derivative" analysis, given close relation between Stability
and Control. and Energy and Information Equivalence [Shannon], and
resultant analogies between Kite Networks and Computer Networks, the
concept of Kite Network Topological Stability nicely matches to
Computer Network Topological Control, as prior art readily applicable
to characterizing novel Kite Network Topological Control.
Kite
tech domain-experts are long aware that tethers and bridles encode
control and stability logic. All formal logic operations are
expressible in string networks, even to comprising Universal Turing
Machines. Kite Network States can be encoded and switched in engineered
bridle multi-configurations and settings. Topological Control is the
conceptual state-of-the-art in AWE, for scalable kite network design.
Topology Control |
| July 3, 2020, post by Dave Santos On the empirical side of the subject are the many
KiteLab/kPower AWES that embody PDS dynamics. On the theoretic side,
there are many applicable principles we have explored, with Strouhal
Number, Re, etc. at the top. PDS is also evident in natural modes of a
toy glider or airplane flown "hands-off", and all things that
spontaneously flap like flags. See also WingMills.
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