Bench inspection!

Last Friday we had the bench inspection session. Our tutor Simon came in the morning. We had an amusing chat about the copter project. We showed him how the copter functions. Afterwards, the assessor came by to see our  progress. 

Group photo with Simon

In the afternoon, Simon brought some UAV amateurs to us and we discussed about the improvements of the quadcopter. It was quite amusing talking to those guys.

Enjoy your Easter holiday and have fun!

Ally & the team

The first test flight outside

Last Thursday we finally managed to go through all the safety considerations and came to the trial flight stage. Here the video shows the first test flight outside the EE building. The wind outside the building was kind of annoying. However, the test flight reveals that the pitch and roll function works well and the throttle configuration should be set lower.

Try again, Fail again, Fail better

Through 5 weeks of study, we have gained much more knowledge doing practice than simply obtaining in documents and books. Reality is always more complex than theory and thus requires a lot more efforts.

Samuel Beckett once said: Try again, fail again, fail better. Now it seems clear to me the importance of every failure is for the sake of the next improvement. It always struck me that when you are looking at a big challenge from the outside it looks huge, but when you are in the midst of it, it just seems normal. Do not hesitate, just get down to business!

Ally & the team

Week 5 ---- Breakthrough

Hi, everyone. After 4 weeks of efforts, the group finally comes to the trial flight stage. However, we were still waiting for the large size 14.8v LiPo battery to arrive. It took us quite a lot of time waiting for the battery but luckily we found an alternative with minor size. The battery, however, was not sufficient for all 4 motors to keep spinning for a long time. Therefore, the large battery is vital for the final flight.

In the tutorial, we had a discuss with Simon about the Raspberry Pi. Kris was confused that the computer seemed to be not connected to the Raspberry Pi since it did not reveal signal of the IP address of the Raspberry Pi. Simon helped Kris find alternatives for the recognition to work.

A picture to reveal the relationship of raspberry pi and the two computers

In the afternoon, we managed to go through several pre-flight checks.

Ran was checking one of the ESCs

Xiaotian was testing the sensibility of the transmitter

Really looking forward to the trial flight test next week!

Until then, I will see you on Wednesday.

Ally & the team

Week 4----under pressure

It is a late post of week 4 update. After tons of trials and experiments, the UAV finally managed to go through the ESCs calibration and the arming successfully. 

The  sudden breakdown of the circuit in week 3 really confused us for a long time and it turned out to be the problem of the power supply. Due to the current limitation of the power supply, when it is supplying power to the UAV, the current will experience a leap and therefore it exceeded the max current load. It is quite a unique problem, however, we figured it out by analyzing the circuit part by part. The tackling of this intractable problem was quite a relief to everyone :) After altering the power supply with a 7.4v LiPo battery, the breakdown of the circuit never happened again. 

The original broken 14.8v LiPo battery 

However, the battery was far from enough to provide power to the main circuit, and thus led to the instability of the spinning of the four motors as shown in the video below:

Arming process showed the instability of the two motors

In the afternoon, we talked to our tutor Simon about our trial flight blueprint. However, Simon, as an expert in UAV arena, considered the trial flight quite seriously. He enlightened us about the possible dangers we might encounter if not fully prepared. The propellers, for instance, would have great power with high speed, which could be a potential danger to human body. Therefore, we had to reconsider different situations and write a safety issue report before we reach the point of the trial flight.

Until then, have a great weekend!

Ally & the team

Week 3 Update of the UAV project

So here comes our week 3 progress. Last week we checked roughly all the calibration process. This week we aimed to reassure the calibration process and complete the esc(electrical speed controller) calibration and finally arm it. 

Last week's lab has instilled us the importance of always having a plan B before the implementation since three of us stuck in the GPS problem for a while and it is really a waste of time. When a certain component goes down, it is vital that we do not all stuck in the condition.

Therefore before this week, we endeavored to list several possible conditions we may encounter and the corresponding solutions. We considered different situations of the pre-arm check and esc calibration. However, the reality is always more unpredictable. We checked the ESC calibration and found no response from the motors which should be spinning when throttle up. We tried to arm the copter but the three of the motors were unstable. We further analysed it to be a problem related to the ESC calibration or the ESC's problem.

With regards to the Raspberry Pi section, Kris has built the foundation of the link and awaiting to connect. Besides, Ran has finished the sonar sensor module which is ready to set up.

See you all next week!

Ally & the team

Week 2 progress!

Hi there, everyone! Here comes our week 2 update of the version 2.0 UAV. 

At the beginning of our second lab, one thing popped out and immediately caught our attention----it seems that a USB wire for the connection of the pixhawk to the computer was lost! This was not an fatal loss, however, it did lag our progress by trying to find a new suitable wire. This has taught us a lesson on keeping gadgets categorized and sorted out before leaving the lab. 

The lab agenda this week is to set up the pixhawk on the UAV and fully calibrate the copter. Waiting for a new battery charger and a 14.7V Lipo battery to arrive, we had to connect the transmitter to the power supply to make it function during the radio calibration period. Without the proper battery, however, we managed to complete the accelerator calibration, radio calibration, compass calibration and flight mode initialization process. The pixhawk, then was checked again by moving around to  judge if the calibration worked (the measured results can be seen on the mission planner). 

The pixhawk-mounted UAV

By then we have done all the calibration and should be able to arm the UAV theoretically. Nevertheless, that might be too insipid an approach for us to carry on. So then the UAV was disarmed and searching for GPS signal. The blue LED kept flashing blue and there was "GPS: no fix" shown on the HUD screen of the mission planner. In that case, it would be unsafe to arm the UAV. 

Therefore we searched for solutions to address the problem. Several factors might cause this problem. We listed them out and tested them one by one. Finally we found that it was because the GPS signal inside the lab was too low and if we wanted to catch the signal we had to move the UAV outside the building. At that instant it would be late to ask for permission to move out the UAV. Therefore, we decided to write to our tutor Simon and have a discussion of it.

Caught the very weak GPS signal(shown on mission planner)

Next week we plan to calibrate the ESCs and arm the UAV so that it might be able to function.

This project is becoming more and more amusing and challenging for everyone. Patience, diligence and implacable purpose may be our weeks to come.

Looking forward!

Ally & the team

Week 1 update

So after our first blog it's time to get down to business.

In the first week, we have managed to go through the initial setup of the UAV, including the pixhawk connections and the mission planner configuration. 

At the beginning, we focused on the ports' connections of the pixhawk. However, after meeting with our tutor and having talking about time management and project allocation, we decided to further split the work.

Problems occurred during the initial setup of the mission planner ---- the LED lights on the pixhawk kept the double yellow flashing mode, which indicated the system refused to arm. As we did not do the compass calibration, it would be implausible to name the error at that moment. Therefore, we will endeavor to address the problem after the construction and calibration procedure.

The connection of pixhawk

Due to the restraint of time, we arranged the task for the next lab. By the end of the next lab day, the platform should be built and all the calibrations are expected to be done.

Looking forward to the next lab!

Ally & the team

Let's get started!

Hi everyone. Welcome to our year two project. I'm Ally and along with my teammates: Kris, Ran, Xiaotian and Yixuan. Our project will use a quad-copter UAV that was initialized by a second year project team last year (Appreciate their work!!). We will try to ensure that the UAV operates effectively and utilize its function in navigating through a 3D environment by the use of the camera and Raspberry Pi. 

It is an achievable goal. However, the project is quite demanding in our patience and group work skills. Since it is a project that contains several separated sessions, the group members are allocated to works that is associated to one component of the project to ensure that everyone takes part in the built.

Now let's get introduced to the team. 

Ran Tao: Ran is our nominated team leader. He is responsible for the work distribution and the project management. He is also the coordinator between the group and our tutor. He will try to make sure that the project is delivered on time and to the required standards. Initially he will focus on the connection of the sensor.

Yiming Hua(Kris): Kris is the main designer of the circuit and the code. He is responsible for the code design of Raspberry Pi. It is the essential part of the utilizing. As such, he will be concentrated on the Raspberry Pi.

Xiaotian Wang: Xiaotian is responsible for the testing of each part of the UAV to ensure its normal function. His work may come across many realistic problems. Initially he will go through the use of the transmitter.

Yixuan Zhang: Yixuan joined as the implementer of the project. He will be dealing with the building and construction of the circuit. At the beginning he will try to figure out the construction of the GPS module.

Mengxi Liu(Ally): I am responsible for maintaining the documentation of the project progress. The blog and poster will be my job to deliver and design. At the meantime, I will endeavor to ensure the functionality of the Pixhawk, which is the flying control of the UAV.

Well that shall end the first post of the UAV blog. The updates will be coming soon!

Ally & the team