water_channel_calcs /

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285 B
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This project contains calculations for the design of captive trajectory/inertial sled
and unified control system for the caltech 40m water channel.

Summary of Python modules in src/ directory:

Provides a single location for storing parameters relating to calculations for
the Caltech 40m water channel project.  Note, some numbers are necessarily
estimates and should be clearly marked as such. In general I have tried to
select all estimated parameters such that they over estimate the forces acting
on the model. 

Estimate of fluid drag on the submarine model and mount -  will be used to help
select the force sensor required or if more than one sensor is needed to span
the full 0-3m/s range. Note, this is only the passive forces not that due to
the actuator. However, if the sub can really go 3m/s per second than the
actuator must be capable of producing at least this much force.

Estimate of fluid dynamic moments on the submarine model and mount - will be
used to help size the air bearing and sensor moment and side load requirements
for this application.  

Purpose: provides a models of the forces and moments acting on the submarine
model and mount hydrofoil. Both the standard square law model and linearized
models force models are given.  The linearized force models are specified by
selecting a desired operating point. Note, this module uses functions in the
force_calcs module.

Purpose: Computes the expected frequency response of the system as a function
of operating point velocity. Plots the amplitude and phase of the system as a
function of the frequency - i.e., produces a bode plot of the system response.
Plots the time constant and 3dB frequencies as a function of operating point

Purpose: provides a simulation of the performance of the captive trajecory
system to help determine the bandwidth requirements for the long range laser
distance sensor and the required update frequency of system's realtime loop.
Simulations of normal (inertial) system response are also provided for
comparison. Plots example trajectories for constant force response. Plots the
percent absolute velocity error as a function of realtime loop frequency. 

Purpose: provides a simulation of the inertial sled system with the goal of
determining the required bandwith for the short range laser distance sensor,
the the required update frequency of the realtime loop and the required motor
performance. Also, provides a method a determining the required system gains.