Automated Golf Ball Launcher

*Fig 1. Final Product of the Automated Golf Ball Launcher

Design Requirement of the Automated GBL

*Fig 2. Objectives Requirement Tree of the Automated Golf Ball Launcher

Concept Analysis of the Automated GBL

For this Golf Ball Launcher mechanism, we will be using some equations that we will discuss below to find the launcher's maximum velocity and the force required for the launcher to launch the ball with that maximum velocity. The two figures below show two different scenarios of the golf ball launcher being shot from the launcher to the designated target.

*Fig 3. Launching Scenarios of the GBL Without and With Bouncing

Scenario 1 (Without Bouncing)

For the first scenario, we will first need to find the maximum velocity of the launcher for the golf ball to reach its target. According to the first figure above, h will represent the launcher's height, where the golf ball starts. The value of h, in this case, will be 2 ft tall. Theta represents the angle that the launcher will be set before launching the golf ball, and for this scenario, the angle will be set to a 45 degrees angle. As for A, it will be the distance between the launcher and the target. The value of A in this scenario will be 6 feet. D1 will be the spot where the golf ball lands

The equation that we will be using to find the maximum velocity required will be written as below:

The acceleration, in this case, will be set to 0, theta will set to 45 degrees, the gravitational acceleration will be set to 32.17 ft/s2, and the value of hmax will be set to -2. Combining those two equations, we will be able to get the value of Vmax from the equation below:

With the value of Vmax known, we can determine the launcher's spring constant, displacement, and the force needed to launch the golf ball to reach its target. The equations can be written as:

Scenario 2 (With Bouncing)

In this second scenario, we need to know what each point represents for the calculation. The letter h from the figure above represents the height where the ball will start, which in this case is 2 ft. The next one is theta, theta represents the angle that the ball will be shot at, and in this case, the angle will be at 45 degrees since it has been proven that a projectile will travels the farthest when it is launched at a 45 degrees angle. The next one would be A and B, where A stands for the distance between the launcher and the first spot the ball landed, and B represents the distance between the first spot the ball landed and the final spot the ball has to land.

The first set of equations that we need are the equations to find A, where those can be written by:

Delta x will be the golf ball movement in the x direction and delta y will be the golf ball movement in the y direction. The acceleration that we use on the delta x equation will be 0, and the gravitational acceleration on the delta y equation will be 32.17 ft/s2. T1 will be the time for the ball to reach D1.

The second equation that we need is the equation to find B. Those equations can be written as:

V1 will be the velocity of the golf ball from point D1 to D max and will be the coefficient restitution which has a value of 0.7. T2 will be the time it takes for the golf ball to move from point D1 to D max.

After combining the x and y for equation A and delta x and delta y for equation B, we will be able to generate a new equation to find t1, t2, and V0. The equations to find t1, t2, and V0 will be:

Even though the equations to find t1, t2, and V0 have been found, we still haven’t figured it out the value for D1. However, there is an equation that we can used to find the specific value for D1 by deriving the equations from the list above. The step by step on how the equations can be found is written below:

Combining equations (6),(7), and (10), we will get:

Therefore, the final equation will be:

By being able to find D1, we can now find V0, t1, and t2. Lastly, we will use the kinematic equations to find the spring constant k and spring displacement x. The equations that we will be using to find k and x can be written as below:

By obtaining the value of k and x, we will be able to determine the force needed to launch the golf ball launcher. The equation to find the force will be:

Dynamic MATLAB Model Outputs Example 1 (No-Bounce)

The first picture on the right will be a sample of the dynamic model visualization result for the no-bounce scenario with the minimum parameter.

Dynamic MATLAB Model Outputs Example 2 (Bounce)

The first picture on the right will be a sample of the dynamic model visualization result for the one bounce scenario with the minimum parameter.

Dynamic MATLAB Model Outputs Example 1 (No-Bounce)

The first picture on the right will be a sample of the dynamic model visualization result for the no-bounce scenario with a random parameter.

Final CAD Design of the Golf Ball Launcher

*Fig 4. Isometric View of the Golf Ball Launcher

*Fig 5. Exploded View of the Golf Ball Launcher

*Fig 6. Parts and Their Materials for the Golf Ball Launcher

Validation

During the assessment, our golf ball launcher succeeded in consideration of most requirements (automatic firing, good distance, good sensory read-outs, good fatigue life). The launcher was able to fire 20 shots consistently, and we had no problem reloading it and firing again. Thus, we succeeded on the front of durability and principled design. However, it is important to recognize that we did have some shortcomings. Due to the gear reduction (5:1), we could not reach a higher angle than 57°, which meant that our launcher could not utilize the full accuracy of our dynamic model. This affected our ability to reach the target angle given by the dynamic model, so our vertical alignment and achieving the target distance were challenging. In this way, we missed the bucket despite our attempts to reach mere inches from the target. Horizontally, these misses could be due to several conditions such as the environmental wind, improper laser alignment, or interfacing issues with the H part and golf ball. Further calibration is needed for future designs, yet overall the golf ball launcher is fully functional.

For the validation of our objectives and goals, we were not successful in accuracy or budget however, we were successful in the launch and design. Specifically, our budget was approximately over the limit by about $20, so we did not maintain that limit successfully. We successfully utilize the laser aiming system, launcher stand, automatic trigger, spring loading system, and circuit designs. Our best-validated requirement was durability, in which our launcher was able to fire many times (test and actual) without any visible striations or failures following our redesign.

If we were to do this project again, or next time when we work on a similar design project, we would be more organized with our schedules and expedite the process to gain more time for field testing. Once we have more time for testing, we can verify the calculations to ensure performance and make adjustments within the given period of time.