Introduction:
Fishing is a popular leisure activity, that people of many ages and backgrounds can partake in all over the world. As a group, we will focus on the people who have trouble with operating certain objects and actions with fishing. Our team will develop an autonomous fishing robot that simplifies the fishing process by performing all tasks independently. Specifically, we are developing a robot to aid people in casting the rod through multiple mechanisms through one to two actions. The casting and reel of the rod will be activated by a button and able to maneuver left and right with a joystick or controller buttons.
Description of the problem:
One of the system's mechanisms will need to be able to cast the line and therefore must move the rod in two different directions. It will move backward to prep the rod for casting, and forward to cast the line. The backward motion must be slower than the forward motion that will cast the line into the water. This variable angular velocity paired with the fact that the direction of motion must alternate makes the profile of motion difficult to accomplish with simple joints alone. A further concern is that during the forward motion, the mechanism should be imparting the greatest amount of force on the rod. This means that variable torque will be a necessary component of our mechanism as well. Looking past the casting motion, one of the mechanisms must be able to reel in the line. For this reason it will need to generate rotational motion and provide substantial torque with minimal input.
Description of Proposed Mechanism:
Describe a mechanism that could solve your problem. You do not need to have this fully fleshed out with links and joints. Give us a general idea of what sort of mechanism you are looking at (i.e., the Geneva mechanism project).
The rod will attach to the end of a table, similar to when the rod rests on a boat
360 degree range of motion when casting the line - allows robot mechanism to move in order to mimic the movement of a bait or struggling fish, increasing the chance of catch
Spinning reel
“With all fixed-spool reels, the line is released in coils or loops from the leading edge of the non-rotating spool. To shorten or stop the outward cast of a lure or bait, the angler uses a finger or thumb placed in contact with the line and/or the leading edge of the spool to stop the flight of the lure. Because of the design's tendency to twist and untwist the line as it is cast and retrieved, most spinning reels operate best with fairly limp and flexible fishing lines.” - Wikipedia
Mechanical casting mechanism - utilizes a spring loaded or motorized system to cast the fishing line when activated by a controller
To solve our problem, will we integrate three different mechanisms, all grounded to a fishing rod mount. The mount will attach to the end of a table or dock, similar to when a rod is resting on a boat. Our design will need to have two different functions, one to cast the line and one to reel it in. We will use two separate servo motors for each of these functions. The reel mechanism will resemble a four-bar linkage, with one junction grounded to the motor and one junction grounded to the reel handle. The casting mechanism will feature 2 functions, the forward-backwards whipping motion of the rod (planar motion), a 360 degree rotation of the rod to pick different areas of the water to cast. For the planar forwards/backwards whipping motion, we will use a gear train to achieve a variable speed of the forward/backwards motion
Proposed Scope of Work:
Preliminary Design Ideas:
Our design will feature 3 different mechanisms to perform 2 different functions: Casting and Reeling. We plan to use three 360 continuous rotation servo motors, one will be used to control the Reel Mechanism and two to control the Casting mechanism. All mechanisms detailed below will be grounded to a mount for the casting rod.
For the reel mechanism, we will use a Galloway Mechanism. This mechanism takes one full rotation of the input link and gives two full rotations of the output link. This will allow us to reel in the line faster while using less power from the motor. Another important aspect of the reel mechanism will be the torque provided to reel in a fish. This will need further analysis, but is an important design consideration.
Example of the Galloway Mechanism in motion:
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Pictured below is the base of the robot. The rod will be mounted in the center of the circle attached by two links to a rotation servo for the 360 degrees of motion.
The casting motion will be generated by a combination of mechanisms.