# Title Team Members TA Documents Sponsor
39 Automated launcher release for a flapping wing robotic bat
Abhishek Bhandari
Kousthubh Dixit
Vyom Thakkar
Jonathan Hoff design_document1.pdf
# Team Members:
Abhishek Bhandari (anb4)
Kousthubh Dixit (kmdixit2)
Vyom Thakkar (vnt2)

# Problem:

We are working on a project that was pitched by Jonathan Hoff. Jonathan and his research group developed a bio-inspired robotic flapping-wing bat robot that mimics the agility and efficiency of bats using silicone membrane wings. The initial robot launcher that was developed by Jonathan did not control the timing of the launch, which leads to different initial positions of the bat wings which ultimately causes the robot to take different trajectories at launch time.

Video link for the bat robot:

Video link for launcher release:

# Solution Overview:

Thus, what we will be working on, is an automated launcher release for the robot that allows the user to control the timing of the launch as well as the position of the wings at launch time which ultimately determines the trajectory that the bat robot takes.

# Solution Components:

## [Subsystem #1] Sensors:
We are planning to use about 3-5 IR sensors and 1-2 ultrasonic sensors. They will all be part of our bat launching device. The IR sensors will be spaced equally vertically (we could 3D print a structure to hold it or build it in the machine shop) such that the lowest sensor corresponds to the lowest height that the wing can go down to. The highest IR sensor will be at a height corresponding to the highest point that the wing can reach vertically. The rest of the IR sensors would be at specifically chosen points in the middle. Using the output of the IR sensors and the associated time stamps, we will extrapolate the coordinates of the wings at a given point in time to define 8-10 wing orientations (different heights). The user can choose the specific wing orientation that he wants to launch at using three switches (more on that in the switches section discussion). Ultrasonic sensors will be placed at the bottom at an angle such that its output would be used to corroborate the existing coordinate data of the wings. (Planning to use: URM06 - Analog Ultrasonic Sensor, Oiyagai 5pcs IR Infrared Barrier Module Sensor)

## [Subsystem #2] Motor, batteries and regulator:
A servo motor (Micro Servo - High Powered, High Torque Metal Gear) would be used to flick a switch that would release the tension in the bow that would launch the bat. Additionally, we are planning to use a micro-controller (Arduino), and a boost switching regulator. We intend to power our device using batteries rather than wall supply as the device is going to be used outdoors.

## [Subsystem #3] Switch configuration and control:
In this project the user can control two parameters: the launch delay time and the position of the wings at launch time which in turn determines the trajectory that the bat robot takes. There will be preset desired trajectories of the bat robot based on its wing orientation. These preset trajectories will be enumerated and the user can select the desired one. Our launching system would trigger the launch of the bat when a user chosen wing orientation is met during the flapping of the wing. The user can also specify the launch delay time which will also be preset and enumerated, for example: 5s, 10s, 15s, etc… In order for the user to specify both the launch delay time and the desired trajectory of launch we can use two control knobs (DAVIES #1100) each capable of enumerating seven different possibilities.

# Criterion for Success:
(1) For a given frequency/flapping rate (8.5 Hz) the system must be able to accurately detect the
position of the wings of the robot and trigger a response that launches the robot when
signaled to by a controller.

(2) System must also accurately trigger the launch of the robot after a user-specified period of
time utilizing the switches on the controller.

(3) For a series of 10 launches there should be no more than an error margin of 15% of the
flapping rate in the difference of the launch time between any two of the launches.

(4) The system must be seamlessly integrated with the launcher in order to avoid collisions and
interference with the launch path of the robot.

Recovery-Monitoring Knee Brace

Dong Hyun Lee, Jong Yoon Lee, Dennis Ryu

Featured Project


Thanks to modern technology, it is easy to encounter a wide variety of wearable fitness devices such as Fitbit and Apple Watch in the market. Such devices are designed for average consumers who wish to track their lifestyle by counting steps or measuring heartbeats. However, it is rare to find a product for the actual patients who require both the real-time monitoring of a wearable device and the hard protection of a brace.

Personally, one of our teammates ruptured his front knee ACL and received reconstruction surgery a few years ago. After ACL surgery, it is common to wear a knee brace for about two to three months for protection from outside impacts, fast recovery, and restriction of movement. For a patient who is situated in rehabilitation after surgery, knee protection is an imperative recovery stage, but is often overlooked. One cannot deny that such a brace is also cumbersome to put on in the first place.



Our group aims to make a wearable device for people who require a knee brace by adding a health monitoring system onto an existing knee brace. The fundamental purpose is to protect the knee, but by adding a monitoring system we want to provide data and a platform for both doctor and patients so they can easily check the current status/progress of the injury.



1) Average person with leg problems

2) Athletes with leg injuries

3) Elderly people with discomforts



Temperature sensors : perhaps in the form of electrodes, they will be used to measure the temperature of the swelling of the knee, which will indicate if recovery is going smoothly.

Pressure sensors : they will be calibrated such that a certain threshold of force must be applied by the brace to the leg. A snug fit is required for the brace to fulfill its job.

EMG circuit : we plan on constructing an EMG circuit based on op-amps, resistors, and capacitors. This will be the circuit that is intended for doctors, as it will detect muscle movement.

Development board: our main board will transmit the data from each of the sensors to a mobile interface via. Bluetooth. The user will be notified when the pressure sensors are not tight enough. For our purposes, the battery on the development will suffice, and we will not need additional dry cells.

The data will be transmitted to a mobile system, where it would also remind the user to wear the brace if taken off. To make sure the brace has a secure enough fit, pressure sensors will be calibrated to determine accordingly. We want to emphasize the hardware circuits that will be supplemented onto the leg brace.

We want to emphasize on the hardware circuit portion this brace contains. We have tested the temperature and pressure resistors on a breadboard by soldering them to resistors, and confirmed they work as intended by checking with a multimeter.

Project Videos