Project

# Title Team Members TA Documents Sponsor
23 Clickers For ZJUI Undergraduate Mk Ⅱ
 Benlu Wang
Luozhen Wang
Suhao Wang
Zhenyu Zhang
 design_document1.pdf
proposal1.pdf
proposal2.pdf
 Fangwei Shao
# TEAM MEMBERS
Zhenyu Zhang (zhenyuz5)
Benlu Wang (benluw2)
Luozhen Wang (luozhen2)
Suhao Wang (suhao2)

# PROBLEM
I-clicker is an educational tool employed by ZJUI to fulfill the digital demands of the classroom, serving as a class check-in and answer device. However, the existing transmitters and receivers face limitations in terms of their capacity to handle substantial loads, high signal delay, and signal loss. These constraints hinder the device's ability to effectively meet the requirements of a large number of users. Additionally, the current I-clicker system fails to cater to the preferences of students who prefer to utilize mobile applications for participation.

# SOLUTION OVERVIEW
This project aims to design and develop a comprehensive classroom response system that supports multiple frontends, including web browsers, mobile applications (iOS and Android platforms), WeChat Mini Programs, and physical Clickers. Additionally, a user-friendly web-based interface will be created to provide teachers with intuitive management functionalities. The system incorporates a high-concurrency unified backend equipped with distributed and in-memory databases, offering caching capabilities to efficiently handle large volumes of student submissions, as well as perform evaluation and statistical analysis. The project also entails the shell design and implementation of a distributed and energy-efficient transmission system for the physical Clickers and their receivers to address the limitation of signal loss.

# SOLUTION COMPONENTS
This project encompasses four essential components: frontend development, backend optimization, hardware improvement, and enclosure design.

## Frontend Development:
For instance, we can develop a user-friendly web-based interface using popular frontend technologies such as HTML, CSS, and JavaScript. This interface can be accessible through standard web browsers on various devices, offering teachers the flexibility to manage the voting result.
Additionally, as part of the meticulous frontend development process, the project aims to provide students with diverse options to interact with the voting system. As we possess a physical clicker as part of our system, our commitment lies in ensuring compatibility and functionality between the mobile app and the physical clicker, allowing both to transmit signals that can be effectively processed by the receiver.
Furthermore, if time permits, the project can also develop WeChat Mini Programs. These lightweight applications within the WeChat ecosystem provide a seamless and familiar voting experience for students who prefer to use the WeChat platform.


## Backend Development:
By constructing a high-concurrency unified backend, fortified with distributed and in-memory databases, the system will be empowered with caching capabilities capable of effectively managing the influx of student submissions.
In this scenario, the system can employ a distributed database system, such as Apache Cassandra or Amazon DynamoDB, to handle the storage and retrieval of student submissions. By distributing the data across multiple nodes, the system can benefit from increased scalability and fault tolerance.
To further enhance performance, an in-memory database, such as Redis or Apache Ignite, can be utilized as a caching layer. This allows frequently accessed data, such as student responses and evaluation results, to be stored in memory for faster retrieval, reducing the need to repeatedly access the distributed database.

## Hardware Improvement:
Recognizing the significance of enhancing reception capabilities, the project dedicates attention to the development of a distributed and energy-efficient transmission system for the physical Clickers and their corresponding receivers. The voting system incorporates a System-on-Chip (SoC) solution to handle both the transmitter and receiver functionalities. The SoC, such as ESP32 or STM32, integrates microcontroller capabilities and offers built-in wireless connectivity options like Wi-Fi or Bluetooth. The SoC transmitter facilitates the transmission of votes from the voting devices to the central system using its dedicated peripherals for user input. The SoC receiver receives the transmitted votes, establishes a reliable connection with the voting devices through Wi-Fi or Bluetooth, decodes the received data, and manages the voting information effectively. This integrated approach utilizing SoC technology ensures seamless bidirectional communication, efficient data transmission, and reliable vote collection within the voting system.

## Enclosure Design:
In addition to the technical facets, the project encompasses the meticulous design of an enclosure, using 3D printing technology, specifically tailored for the physical Clickers. This component embraces the principles of aesthetics, functionality, durability, ergonomics, and user-friendliness. By prioritizing these design considerations, the enclosure aims to enhance the overall user experience, ensuring that the physical Clickers are comfortable to handle and operate.

# CRITERION FOR SUCCESS

Concurrency Handling: Build a high-concurrency backend system for efficient processing of large volumes of student submissions concurrently.

Affordability: Develop cost-effective i-clickers to promote widespread adoption and accessibility for students.

Support for Multiple Frontends: The system should be designed to support multiple frontends, including mobile applications, web browsers, and dedicated software, ensuring compatibility, seamless interaction, and consistent user experience across various platforms.



Signal Stability: Ensure reliable signal reception in challenging environments and minimize signal loss within classrooms.

Distributed and Energy-Efficient Transmission: Implement a distributed transmission system with low-power consumption to optimize device performance and energy efficiency.

Aesthetic Design: Create visually appealing i-clicker shell designs that are widely accepted and facilitate customization through 3D printing.

# DISTRIBUTION OF WORK
Benlu Wang: Responsible for designing and developing web-based interfaces, mobile applications, and WeChat Mini Programs to provide a range of frontend options for students to interact with the voting system.

Zhenyu Zhang: Tasked with optimizing the backend infrastructure, including the development of a high-concurrency unified backend, distributed and in-memory databases, and efficient data management for seamless operations.

Luozhen Wang: Responsible for designing and creating customized enclosures for the physical Clickers using 3D printing technology, ensuring an aesthetically pleasing, functional, and user-friendly design.

Suhao Wang: In charge of improving the hardware components of the voting system, particularly focusing on the development of a distributed and energy-efficient transmission system using System-on-Chip (SoC) technology.

simplified device for fasteners counter

Zhiwei Shen, Shuyang Wang, Yijian Yang, Jinsong Yuan

Featured Project

# PROBLEM DESCRIPTION

Lots of Industrial manufacturers need to realize real-time, efficient and accurate automatic counting of the assembly line products in the stages of production and transportation. On a standardized assembly line with stable operations, equal intervals and boxed objects the control system with infrared detection and microchip as the control core is effective and simple to implement. However, due to cost considerations, downstream manufacturers often prefer faster and less standardized assembly line operations during product inspection. Those unpackaged objects may have complex and changeable structures, and different kinds may have very similar structures. Moreover, the intervals and directions of these products on the assembly line are all random, which greatly increases the difficulty of monitoring, as well as achieving subsequent controlling purposes such as mechanical classification or equal-quantity loading.

After we discussed with people from a manufacturer, we realized their needs in this regard, so we decided to design an effective and low-cost device that realizes real-time monitoring and controlling towards specific industrial products with complex and random structures. From our investigations, we found that some factories use image recognition technology to achieve this goal, which turned out to be insufficient and costly because of their improper design. The manager of company complained about the stability, flexibility and fee of the traditional ways. After listening to the manager, we decide to implement our own ways to count line products, and our target is to increase the stability, flexibility and lower the cost.

By doing some research online, we confirmed that the most common monitoring system is still the infrared detection and microcontroller/PLC, which is effective for most assembly lines with products in boxes. And some newly developed approaches are based on cameras and computer vision, which we think are very potential but costly. Also, we found some other engineers still used simple infrared detection to achieve non-boxed objects monitoring. However, they met similar accuracy issues, like when two objects are too close to each other. Not to mention the objects that we are going to detect have much more complicated structures. In a word, we didn’t find any other monitoring system without using computer vision that can achieve our accuracy goal. So, our first major task is to come up with a better algorithm. We may also try pressure sensors, which is rarely used in assembly line object counting. In fact, we are going to investigate the feasibility of our idea by doing some experiments at their factory this week.

The scope of this specific problem might involve designing an embedded system with sensors and microcontroller unit to achieve the industrial control purpose, as well as programming and data analysis. Moreover, it may involve some knowledge about IoT because we also hope to use network module to transfer data and improve the automation level.

# solution overview

We plan to use infared sensor to dector the fasteners on the pipeline. We have two different kind of infared sensor in schedule. The first type could detect whether there exists objects within one meter, and the other one, which uses laser at the same time, can measure the distance between the surface of fasteners and the detector. The first one is cheaper but the second one could provide more imformation. We would choose in terms of real condition. There are also some alternative plans: we plan to use pressure sensor to count the total mass coming in and then calculate the number; acoustic rangefinder is another way to detect the distant in place of the second kind of infared sensor, and we will choose this plan if the original plan doesn't work so well.

Then, we plan to use PRI or PLC to process imformation. RPI is more powerful and enable us to write more complex code and develop some complicated functions such as classification of fasteners and nerual network which can analyze cutting pieces of fasteners, but PLC would be more stable in industry environemnt. The choice is mainly determined by real industry environment and the comments from manufacturers. We tend to use PLC to handle imformation from detectors and command the pipeline.

As for pipeline, workers put fasteners on the track. During the transportation, our device would count the number and in the end of pipeline, fasteners would be packed. After collecting enough fasteners, our machine would stop the pipeline.

# Solution Components

- Mono-chip（Raspberry Pi）

Price: around 300￥

Function: Receiving the data collected by the detector, processing it to get the number of fasteners that have passed, and transmitting the data to the remote-control center through the wireless interface.

We are going to use the neural network for modeling and use this model to count.

- Pressure-sensitive sensor

Price: 10￥-200￥

Function: Measuring the real-time weight on the sensor to assist in determining the number of products passed.

- Infrared sensor

Price: Already have

Function: Determining whether there is product passing.

- Laser rangefinder

Price: 60￥-200￥

Function: Measuring the distance between the product to the boundary of the conveyor belt.

- Acoustic rangefinder

Price: 200￥-300￥

Function: Measuring the distance between the product to the boundary of the conveyor belt.

- Remote-control Center

Price: Already have

Function: Receiving the data transmitted by the mono-chip, presenting the past products so far, and commanding every component according to that.

# CRITERION FOR SUCCESS

- High accuracy is required. The counter should have a error rate at 1%+-0.1%.

- The classifier is supposed to perform well, then the device can be migrated to a similar pipeline. The device is a kind of baler. When the input products are not of the same kind, if there is no classification function, packaging errors are likely to occur.

- The process of counting and classifying should take less time.

- The devicey should be stable enougth to be used in manifacture.

- Additional Function: Operator can control the machine and see results easily and remotely.

# sponsor

This project is well connected to industry. The company that sponsors us is 杭州六联机械科技有限公司(Hangzhou Liulian Machinery Technology Co., Ltd.) and the manager with whom we talked is 杨向峰(Xiangfeng Yang).