## EMILY'S BLOG

### I never dreamed about success. I worked for it. -Estee Lauder

This is our package that will hold the fruits.

In Project Collisions, my group is creating a system to deliver fresh fruits by drones. The drones will drop a package from a height of 10 meters, and it is our job as engineers to develop a solution so that the package is protected in its fall. For Drop 0, our box has the dimensions of 20 x 20 x 30 cm (length, width, height), and was dropped from a height of 5 meters. This is the photo of the package:`

The box will hold 4 apples (weighs about 400 grams), a box of blueberries (about 340 grams), a box of strawberries (about 1,000 kg), and 8 tangerines (about 960 grams). The two boxes of strawberries and blueberries will go at the bottom of the box, and the apples and tangerines will go on top of the strawberries and blueberries.

My drawing of what will go inside the package.

The purpose of Drop 0 is like the “control” in our experiment, to get the baseline data about our package. Our group developed a procedure so that we can be consistent about how we are dropping our package and collecting data.

During our first drop, we didn’t line the package up with the arrow mark properly, so the box didn’t hit the force plate and we weren’t able to collect data for the force of the landing. After opening the box, we also noticed that the fruits weren’t that badly damaged, only a few bruises on the strawberry and blueberries, so now we know how to protect the fruits from getting damaged. Below is the data we’ve collected so far:

The procedure and data table.

The package took 1.08 seconds from the moment it was released to the moment it was dropped, and we used LoggerPro to plot out the fall of our package. Below is the image of the plotted points of our package. At first, the package didn’t drop very much, which is why the points are plotted so close together. But the box’s velocity increased as it dropped further down and gained momentum, which is why they grew further apart. At the end, the package also bounced off the table, which is why there are many dots bunched together at the end.

A force plate was set up at the bottom to collect data on the impact force of the package. One of our metrics of success was if the package hit the force plate and the force plate was able to collect data. For our first drop, the package did not hit the force plate, so we weren’t able to collect data for Drop 0, but for Drop 1, we were able to successfully hit the force plate. Our average force on impact was 28.9 newton’s. Our goal is to be able to hit the force plate, which is a 28.5 by 31.5 cm area. Our goal for our first design is to reduce the force impact to 15 newton’s, and if we can reach that goal, we will keep reducing the number so we can have a softer landing. We are also planning to do this with the velocity as well.

The data we collected put into LoggerPro.

Our team has decided that these metrics of success are the most important criteria that our design should follow:

1. Fruits should not be damaged (eg. bruised, juice seeping out, squashed)
2. Package hits the force plate
3. The force impact is 15 newton’s or less
4. The velocity is 1.6 / second

Below, each metric is described and the goals were determined based on data we have collected from Drop 0.

1. Fruits are in mint condition
2. The package hits the force plate
3. The force impact is 15 newton’s or less
4. The velocity is 1.6 m / second

Our group is now building our first prototype. We are planning to slow the fall with a parachute, and have some padding at the bottom of the box for protection. I hope that we are able to meet all our goals for Drop 1, and will be able to learn more from the data we are collecting.

## 1 Comment

1. Thanks! Frank