Week 9/21 to 9/28

This week, our team met up with the vehicle control team to discuss about the feasibility of the Hall Effect sensors on both positioning and switching. Both team came up with the idea of using the Hall Effect sensor’s digital output as the positioning tool and using a second sensor for switching and detecting the magnets on the track. Originally we would like to keep the design of the Korean team. However, this idea was rejected by the Track development and Bogie team because the magnetic detector on the podcar will contact with the track. And the hold system needs to be redesigned if the control team wants to keep the magnetic detector. We tested the RFID sensor, but fail to make it work properly. Our team started searching some of the smaller Hall Effect sensors. And we are getting an A3144 Hall Effect sensor in recent days.

The team is also working on searching possible corrugated metal strip supplier on the market. We are looking for products similar to the metal strip that we want, and trying to contact the manufacturer of the product to search for possible assistance.

Vehicle Position Sensing Team Week 9/14/2016 – 9/21/2016

The week, the team was focus on testing the Hall Effect sensor, the test was done on Arduino base test environment. The circuit was constructed as shown: 

The Arduino was programmed using the following simple code:

#define hall 0

void setup() {

  pinMode(hall,INPUT);

  Serial.begin(9600);

}

void loop() {

  sensorValue = analogRead(analogInPin);

  Serial.print(sensorValue);

  delay(2);

}

Conclusion for Testing:

• The Sensor only can only detect ferrous object inside a 3mm range.
• The sensor we used for testing only outputs digital signal, which means its reading might not be effected by the magnets on the track.
•  The team tested the sensor with a magnets, the result confirmed that the sensor is not affected by magnets.

Recent plans

• The team need to find new corrugated ferrous strips with much narrower spacing between peaks.
• The team is looking for a new type of Hall Effect sensor which is able to provide analog output.

Vehicle Position Sensing Team Week 9/7/2016 – 9/14/2016

This week, our team has talked to Dr. Furman about the feasibility of using Hall or GMR sensors and corrugated ferrous strip to build the position sensing system. Dr. Furman has introduced the Hall Effect sensors and his idea about accurate position sensing system for the 1/12 scale model. After the discussion with Dr. Furman, our team listed out some difficulties and key parts of our plan.

1. The team has to test if the sensors are able to detect the ferrous strip and give correct feedbacks as we expected. And the test will be done using a large scale ferrous strip and sensor.
2. If the idea work, the team should figure out the size of the ferrous strips in order to achieve a high resolution sensor feedback.
3. There is limiting space between the vehicle and the track, the team have to figure out a way to attach the ferrous strip and the sensors on the track and the car.
4. The team must find the manufacturers which are able to provide us assistance on manufacturing high quality ferrous strips, otherwise we have to make it ourselves.

In conclusion, Dr. Furman provided plenty of useful information for our team, and the team has start working on the testing of sensors.

Configuration of Hall Effect Sensor and Ferrous Strip

Testing Circuit

Team Blog Assignment #1

• Members:
• Name: Qihuan (Kevin) Miao
• Skills: Matlab, Arduino coding, CAD drawing, C++
• Contact: Cell: 415-4268953 Email: miaokevin@hotmail.com
• Responsibilities: Coding, sensor testing, researching

• Name: Zhiwei Li (Alex)
• Skill: Arduino coding, Solid Work, CAD drawing
• Contact: Cell: 415-216-6084 Email: zli52@mail.ccsf.edu
• Responsibilities: Mechanical Part, Researching, sensor testing

• The Position sensing team is supposed to work with other vehicle control teams to develop a “smart” and autonomous multiple-podcar system. The main focus of the team is to solve the positioning problem in order to create an accurate and reliable podcar positioning system for the twelfth scale model this year. The team is supposed to work out position sensing system with linear magnetic encoders systems. The linear magnetic encoder system will be created by implement hall effect sensors and neodymium magnets with a corrugated piece of sheet metal on the guide way.

• Major task in recent weeks:

• Budget Estimate: Between $100 - $300