Soldering Assignment

Description

The soldering assignment is a basic soldering exercise that ensures all ECE 445/ME 470 students understand how to solder surface-mount and through-hole devices. Students will be provided with the necessary PCB, components, solder, flux, etc. The details of the soldering assignment can be found in the assignment sheet.

Your end product should look similar to the following. You will create a small device that blinks an LED at varying frequencies when the button is pressed, based on a potentiometer reading.

Soldering Assignment Image

Below is a series of soldering tutorials. The critical ingredient that you need to make your life easier while surface mount soldering (and through-hole too) is flux. There is liquid, water-soluble flux available in the lab. If you can't find it or don't know what it looks like, ask a lab staff member or TA for help.

Requirements and Grading

The soldering assignment is worth 10 points and is graded via inspection by a TA or Lab Staff member. Students are allowed to make as many attempts as necessary to complete the assignment.

Submission and Deadlines

The soldered PCB must be presented to a course staff member before the deadline listed on the Course Calendar.

Video Tutorials

Below are a few public video tutorials on Soldering. There is also a text description of how to solder on the soldering assignment doc linked above.

Through-hole (THT) and surface-mount (SMD) soldering tutorial:

Tutorial on using the various types of flux:

Tutorial on using wick to remove solder:

Tutorial on using a heat gun:

Keebot, a humanoid robot performing 3D pose imitation

Zhi Cen, Hao Hu, Xinyi Lai, Kerui Zhu

Featured Project

# Problem Description

Life is movement, but exercising alone is boring. When people are alone, it is hard to motivate themselves to exercise and it is easy to give up. Faced with the unprecedented COVID-19 pandemics, even more people have to do sports alone at home. Inspired by "Keep", a popular fitness app with many video demonstrations, we want to build a humanoid robot "Keebot" which can imitate the movements of the user in real time. Compared to a virtual coach in the video, our Keebot can provide physical company by doing the same exercises as the user, thus making exercising alone at home more interesting.

# Solution Overview

Our solution to the create such a movement imitating robot is to combine both computer vision and robotic design. The user's movement is captured by a fixed and stabilized depth camera. The 3D joint position will be calculated from the camera image with the help of some neural networks and depth information from the camera. The 3D joint position data will be translated into the motor angular rotation information and sent to the robot using Bluetooth. The robot realizes the imitation by controlling the servo motors as commanded. Since the 3D position data and mechanical control are not ideal, we leave out the consideration of keeping robot's balance and the robot's trunk will be fixed to a holder.

# Solution Components

## 3-D Pose Info Translator: from depth camera to 3-D pose info

+ RealSense Depth Camera which can get RGB and depth frames

+ A series of pre-processors such as denoising, normalizing and segmentation to reduce the impact of noise and environment

+ Pre-trained 2-D Human Pose Estimation model to convert the RGB frames to 2-D pose info

+ Combine the 2-D pose info with the depth frames to get the 3-D pose info

## Control system: from model to motors

+ An STM32-based PCB with a Bluetooth module and servo motor drivers

+ A mapping from the 3-D poses and movements to the joint parameters, based on Inverse Kinematics

+ A close-loop control system with PID or State Space Method

+ Generate control signals for the servo motors in each joints

## Mechanical structure: the body of the humanoid robot

+ CAD drawings of the robot’s physical structure, with 14 joints (14 DOF).

+ Simulations with the Robotics System Toolbox in MATLAB to test the stability and feasibility of the movements

+ Assembling the robot with 3D print parts, fasteners and motors

# Criterion of Success

+ 3-D pose info and movements are extracted from the video by RealSense Depth Camera

+ The virtual robot can imitate human's movements in MATLAB simulation

+ The physical robot can imitate human's movements with its limbs while its trunk being fixed