Project

# Title Team Members TA Documents Sponsor
66 Self-playing Programmable Chromatic Harmonica
 David Zhang
Robert Zhu
Sean Jasin
 Wenjing Song design_document2.pdf
final_paper1.pdf
presentation1.pdf
proposal1.pdf
video
# Team Members:
-Sean Jasin (sjasi3@illinois.edu)

-Robert Zhu (robertz4@illinois.edu)

-David Zhang (dzhan6@illinois.edu)

# Problem:
The harmonica is a versatile, simple, yet technically difficult instrument to play. There is a need for the background music of a live instrument, yet it is difficult to master the harmonica. Some lack the time to practice and learn the harmonica. For others, they may no longer be able to physically play the harmonica, or do not have access to training or musical education. Existing musical devices exist for keyboard and string instruments, but not for wind instruments. There is a need for a self-playing harmonica that can produce melodies without requiring manual lip or breath control.

# Solution:
The solution is a device that is able to play the harmonica. The self playing harmonica consists of multiple subsystems. The power supply provides power at all required voltages for the MCU, air pumps, and electronic pneumatic valves. The harmonica-computer interface connects to both the harmonica and the MCU, and is responsible for controlling the flow of air through the harmonica. It consists of pneumatic tubes, air pumps, and electronic valves. The MCU is responsible for controlling the pumps and valves in the harmonica-computer interface, as well as taking a MIDI file and converting it into a sequence of pump and valve motions. Lastly, songs are uploaded to the MCU through WiFi. We will create a website where the user can upload a MIDI file and that file is then available to play on the device.

# Subsystems:

Power supply

Motor driver

MCU

Harmonica-computer interface

Website for uploading MIDI files

## Power supply (located on the pcb)
The power supply must be capable of supplying 3.3V, and 12V power to the device. The 3.3V power supply is for the MCU and the 12V power supply is used by the pneumatic valves. We will utilize an AL-12100 12V 120W power supply that plugs into a wall outlet. We will then convert the 12 power supply into the signal voltage, 3.3V, on the PCB.

## Motor driver (located on the pcb)
The motor driver will allow the ESP32 to control the DC motor because the output of the GPIO on the MCU cannot provide enough power (GPIO 3V3 @ low current, motor needs 12V). The output of the motor driver will be a 12V PWM signal.

## MCU
For the MCU, we will use an ESP32 for its WiFi capabilities. The MCU has 2 functions: mechanical control and MIDI upload. The mechanical control will take MIDI inputs and play the respective note on the harmonica. This will be controlled by several valves which will allow us to control the airflow into the harmonica.

## Harmonica-Computer Interface

Harmonica:
The harmonica that we will be using for the project will be a Conjurer-brand 10-hole chromatic harmonica. This harmonica was chosen due to its budget-friendliness, as well as its ability to play semitones without the requirement of “bending”, when one uses their tongue to play semitones.

Air pump:
We will use a Mini 555 Dongguang air pump to supply a constant and variable air flow. The airflow will be changed to control for volume, with a maximum of 15 LFM or 0.53 CFM. This should allow us to be able to play 10 notes simultaneously. The airflow of the output will be determined by PWM duty cycle, which will allow us to control the volume of the harmonica. The static pressure requirement of the pump is inconsequential, as harmonicas do not require significant air pressure to play.

Electronic valves:
The electronic valves will consist of 10 Laccimo 2V025-1/4 12V solenoid valves and one Airtac 4V110-08F 5/2 12V solenoid valve. This will allow air input and output from each hole of the harmonica, as well as switching action between blowing air and sucking air.

High-Torque Servo:
To operate the slider, a high-torque servo will be used. The DS3218MG has a sufficient control angle and has enough force (20kg) to operate the lever at a fast speed and in a precise manner.

## Website
Using the ESP32’s WiFi capabilities, the MCU will host a mini server on which a user can upload MIDI files. These MIDI files can then be processed by the MCU to be played by the harmonica.

# Criterion for Success:
The success of this project will be based upon these criteria:

Must be able to blow in and suck out air of all holes in a chromatic harmonica

Must be able to achieve the full range of airflow from 100 to 400 LFM. (equivalent to 0.009 CFM to 0.025 CFM given a 4mm x 10mm sized opening).

Ability to engage and disengage the slide of a chromatic harmonica.

Dynamics/volume control of each played note is accurate and successful.

A .MIDI file is able to be uploaded to the website of the self-playing harmonica system.

A .MIDI file is able to be transmitted to the MCU via WiFi and performed accurately by the self-playing harmonica system.

The system must be robust enough to play for 10 minutes continuously.

WHEELED-LEGGED BALANCING ROBOT

Gabriel Gao, Jerry Wang, Zehao Yuan

WHEELED-LEGGED BALANCING ROBOT

Featured Project

# WHEELED-LEGGED BALANCING ROBOT

## Team Members:

- Gabriel Gao (ngao4)

- Zehao Yuan (zehaoy2)

- Jerry Wang (runxuan6)

# Problem

The motivation for this project arises from the limitations inherent in conventional wheeled delivery robots, which predominantly feature a four-wheel chassis. This design restricts their ability to navigate terrains with obstacles, bumps, and stairs—common features in urban environments. A wheel-legged balancing robot, on the other hand, can effortlessly overcome such challenges, making it a particularly promising solution for delivery services.

# Solution

The primary objective of this phase of the project is to demonstrate that a single leg of the robot can successfully bear weight and function as an electronic suspension system. Achieving this will lay the foundation for the subsequent development of the full robot.

# Solution Components

## Subsystem 1. Hybrid Mobility Module:

Actuated Legs: Four actuator motors (DM-J4310-2EC) power the legged system, enabling the robot to navigate uneven surfaces, obstacles, and stairs. The legs also functions as an advanced electromagnetic suspension system, quickly adjusting damping and stiffness to ensure a stable and level platform.

Wheeled Drive: Two direct drive BLDC (M3508) motors propel the wheels, enabling efficient travel on flat terrains.

**Note: 4xDM4310s and 2xM3508 motor can be borrow from RSO: Illini Robomaster** - [Image of Motors on campus](https://github.com/ngao4/Wheel_Legged_Robot/blob/main/image/motors.jpg)

The DM4310 has a built in ESC with CAN bus and double absolute encoder, able to provide 4 nm continuous torque. This torque allows the robot or the leg system to act as suspension system and carry enough weight for further application. M3508 also has ESC available in the lab, it is an FOC ESC with CAN bus communication. So in this project we are not focusing on motor driver parts. The motors would communicate with STM32 through CAN bus with about 1 kHz rate.

## Subsystem 2. Central Control Unit and PCB:

An STM32F103 microcontroller acts as the brain of the robot, processing input from the IMU through SPI signal, directing the motors through CAN bus. The pcb includes STM32F103 chip, BMI088 imu, power supply parts and also sbus remote control signal inverter.

Might further upgrade to STM32F407 if needed.

Attitude Sensing: A 6-axis IMU (BMI088) continuously monitors the robot's orientation and motion, facilitating real-time adjustments to ensure stability and correct navigation. The BMI088 would be part of the PCB component.

## Subsystem 3. Testing Platform

The leg will be connected to a harness as shown in this [sketch](https://github.com/ngao4/Wheel_Legged_Robot/blob/main/image/sketch.jpg). The harness simplifies the model by restricting the robot’s motion in the Y-axis, while retaining the freedom for the robot to move on the X-axis and jump in the Z-axis. The harness also guarantees safety as it prevents the robot from moving outside its limit.

## Subsystem 4. Payload Compartment (3D-printed):

A designated section to securely hold and transport items, ensuring that they are protected from disturbances during transit. We will add weights to test the maximum payload of the robot.

## Subsystem 5. Remote Controller:

A 2.4 GHz RC sbus remote controller will be used to control the robot. This hand-held device provides real-time control, making it simple for us to operate the robot at various distances. Safety is ensured as we can set a switch as a kill switch to shutdown the robot in emergency conditions.

**Note: Remote controller model: DJI DT7, can be borrow from RSO: Illini Robomaster**

The remote controller set comes with a receiver, the output is sbus signal which is commonly used in RC control. We would add an inverter circuit on pcb allowing the sbus signal to be read by STM32.

Note: When only demoing the leg function, the RC controller may not be used.

## Subsystem 6. Power System

We are considering a 6s (24V) Lithium Battery to power the robot. An alternative solution is to power the robot through a power supply using a pair of long wires.

# Criterion For Success

**Stable Balancing:** The robot (leg) should maintain its balance in a variety of situations, both static (when stationary) and dynamic (when moving).

**Cargo Carriage:** The robot(leg) can be able to carry a specified weight (like 1lb) without compromising its balance or ability to move.

_________________________________________________________________________

**If we are able to test the leg and function normally before midterm, we would try to build the whole wheel legged balancing robot out. It would be able to complete the following :**

**Directional Movement:** Via remote control, the robot should move precisely in the desired direction(up and down), showcasing smooth accelerations, decelerations, and turns.

**Platform Leveling:** Even when navigating slopes or uneven terrains, the robot should consistently ensure that its platform remains flat, preserving the integrity of the cargo it carries. Any tilt should be minimized, ideally maintaining a platform angle variation within a range of 10 degrees or less from the horizontal.

**Position Retention:** In the event of disruptions like pushes or kicks, the robot should make efforts to return to its original location or at least resist being moved too far off its original position.

**Safety:** During its operations, the robot should not pose a danger to its surroundings, ensuring controlled movements, especially when correcting its balance or position. The robot should be able to shut down (safety mode) by remote control.

Project Videos