Individual Progress Report

Description

The Individual Progress Report (IPR) is a chance to put your contributions to the team's progress in writing. The report will discuss not only the components and subsystems you have personally been responsible for, but what components you have helped work on as well. It is important to talk about the relation between your work and your teammates' work as well.

Requirements and Grading

This report should be 5-12 pages of your own work. This means that you cannot take paragraphs/text from your Design Review document, since that was a collaborative effort. The IPR Grading Rubric describes what we look for in grading this assignment. The requirements are expanded on below:

  1. General: Concise writing is encouraged, but it is important that all pertinent information is conveyed. All figures should be labeled and formatted consistently.
  2. Formatting: Please refer to the Final Report Guidelines for general writing guidelines, since the format of this report should be very similar to that of the final report. Note that each component of the Final Report may be tailored to the parts of the project the individual has been active in.
  3. Introduction: First, discuss what portion of the system you have been active in designing connects to which portion of a different subsystem, and how these interact to complete an overall objective. Then discuss what you have accomplished, what you are currently working on, and what you still have left to do.
  4. Design: Discuss the design work you have done so far. It is expected that you have done calculations and/or found relevant equations, created circuits for your parts of the project, and simulated / drawn schematics for your parts. You may have already, at a high level, discussed how your part fits into the rest of the project, but you should expand on the technical details and interface between your module(s) and the other modules of the project.
  5. Verification: Testing and verification is also very important. Make sure you describe each test that was performed and its procedure in detail, and give quantitative, meaningful results. Also describe tests that have yet to be performed. We should be convinced that if all your tests will pass, your part of the project will work.
  6. Conclusion: Discuss a plan and timeline for completing your responsibilities and your project as a whole. Also explain the ethical considerations of your project by consulting the IEEE Code of Ethics, ACM Code of Ethics, or another relevant Code of Ethics.
  7. Citations: You need citations. Cite sources for equations, Application Notes you referenced in your design, and any literature you used to help design or verify your work. If you checked something from another course's lecture slides, Google'd for things related to your project, or anything similar, then you have something you need to cite. At the very least, since you have talked about the ethical considerations of your project as it relates to a published code of ethics (e.g., IEEE or ACM), you should cite those!

Submission and Deadlines

The IPR should be submitted on canvas in PDF format by the deadline listed on the Course Calendar.

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.

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**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