Active Velocity Control Bait Casting Reel for Fishing

I had, a few years ago, been thinking about fishing with baitcasting reels. One big advantage that I enjoy is being able to control the speed of the line coming out with my thumb.

One disadvantage is the spool can spin too fast causing a nasty "birds nest" of line on your spool. Another disadvantage is the cast distance is minimized by the techniques used to not allow that to happen.

The common technique is to use mechanical braking to minimize the spool speed again at the expense of cast distance.

A few years back, Shimano came up with a technology that uses a computer to "shape" the braking pattern so the braking can be non-linear and tuned to the time of the cast. So I suppose it would allow faster spin rates at the beginning then, as toward the end of the cast, it could increase the braking, thus helping cast distance while still minimizing backlash.

Check out this site for their description of this cutting edge tech:

http://fish.shimano.com/publish/content/fish/sac/us/en/dc_technology.html

These reels are pricey, I plan to get one this spring. The tech is so compelling.

I think the next big step in this process is to come up with a way that the reel could actively adjust the speed of the spool. The difference is somewhat analogous to passive versus active suspension in autos. The current state of Shimano technology is still passive, computer controlled non-linear brake shaping. With Active Velocity control, the reel needs to adjust the braking in a non-linear fashion, but also in a way that can actively in real-time, adjust braking. This will help when discontinuities in the velocity occur which can minimize massive backlash.

What is backlash?
In mathematically I suppose backlash is when the spool velocity (w) exceeds the line velocity (v) divided by the radius of the spool. (radius in not constant)

w > v / r

So if we can electronically brake the spool we just need to apply the braking when the above equation true until

w = v / r

The solution
If somebody were to build a computer to calculate the optimal spool velocity and compare it to the actual one, braking when the actual spool velocity exceeds the optimal one, backlash would disappear. A nice side benefit is that the spool can then be engineered mechanically, such that the more spin resistance is minimized, the further the reel will cast.

Measured inputs
We will need to measure the following values.
Actual spool velocity.

This problem has already been solved in many ways, even in current fishing reels. One way would be to use an opticoupler like ones found in computer mice.
Spool radius.

This also has been addressed in current fishing reels. Abu-Garcia has a line trolling computer that has the user enter the percent amount that the reel is filled with line, when all the line is in. Then, by counting the spool revolutions, they can presumably estimate the current spool radius.
Line speed.

Here we need to measure the speed at which the line is actually coming off the reel, independent of the spool speed. The technique that first comes to mind would be to manufacture a metered line with very small metering distances. Maybe the opacity levels are toggled with the metering. Then using light detection techniques as the line passes through the eyehole portion of the spool used to evenly wind the line onto the spool, the speed could be measured, taking care to handle aliased velocities by the lengths of the metering.


Applying the solution. In order to successfully create a product using active braking, a good deal of design must be undertaken. The majority of the work is in measuring accurately and cost effectively, those elements listed above.

result: a better mouse trap