Presentation #3 Motor Controls Update (Pictures Below)

This week the controls team went over our final presentation of the year. We have made great strides through the semester. As of right now we have a working motor model prototype that can be found in our Presentation slides. This working model will allow us to found out how to attenuate the motors so they can communicate with one another and work in tandem as if a differential were driving the two motors. Each motor is a small drone BLDC motor that is operated by a potentiometer. This potentiometer value can be changed to change at what values the motor will run and at various speeds. As the potentiometer is turned to its max value, the motor runs at maximum speed. However as the speed grows higher, the noise frequency tends to become a bit high and unpleasant so I will consider capping it at a safe range to avoid unwanted frequency vibrations. Looking ahead towards the final weeks and next semester, there are still many things to be done. Going forward there is the need to fix the motor model and make sure the wires are safely placed to avoid unwanted arcing or shorts. Increasing the modularity of the motor model will help us later on when the actually bogie motors come in and we will be able to transfer the code and concepts from the small prototype model the full scale model with little needs for adjustment. Continuous changes such as updating the motors with encoders to be able to calculate the speed of each motor, adding resistors to make the motors spin slower at certain moments, and separating our power leads from the rest of the circuit to avoid any damage. The next step is to run two of the motors simultaneously with one battery source in order to mimic the full scale model as closely as possible. Each axle on the bogie will probably have one ultra capacitor cell attached to it and being able to get the current to the motor with the least amount of resistance will help keep the current high with minimal voltage and current drop over time when the bogie will have to go about 10 meters of track before recharging again so keeping current high and stable is a key insight that the team must attend to with wayside power to make sure the motors are constantly working. If the motors were to stall in the middle of a trip, it may spew disaster as another car may crash into it or the person could be stuck on a floating island for a few hours before rescue workers can clear the line and rescue the person in immediate danger. Many more safety factors and prototyping has to be done before moving on to the finished product so we avoid as many setbacks as we can on the real motor and motor controllers.
The motor model can be found below. A few immediate modifications is to add fuses to avoid and shorting or frying of the equipment.

10/10 - 10/17 Continue of Research and Rapid Prototyping

The last two weeks have included more research into the concept of BLDC motors and their integration into the system with the respect to how we will control the motors simultaneously without the use of a differential to help mitigate problems when the bogie comes to a turn junction. Several elements of tracking are also being discussed with Furman and various other members from the other full scale design teams with where we will be able to place our tracking sensors to determine where the bogie is at all time steps to ensure we know where the bogie is and code accordingly based on user input and where the bogie is on the track. Without having a differential leads to many difficulties in our design of a control system. With the use of ultracapacitiors, we will need to vary the amount of voltage and current coming the the DC/DC converter to change how fast the hub motors will spin to induce what a differential role is which is to slow down and speed up opposite wheels in a turn to mitigate the forces acting on the car and avoid the bogie from jerking and possibly causing unwanted stresses that could be detrimental to the system as a whole. We plan on ordering a few BLDC motors to get a rough concept on how to control them simultaneously to make them act as if they are attached by an axle and help start sorting out he bird's next of wires. We also anticipate keeping the motors powered at all times unless docked into a station and controlling them through an alternate circuit that is connected through the controller to the motor to avoid differing voltages that could possibly fry our equipment such as our Arduinos and other fragile sensors and equipment. We plan to meet this coming Friday to hash out our ideas and slides for our second Presentation to present how we plan to attack these various problems the rest of the semester and moving into next semester.

Update 10/4/18 Advancement on Control System for Full Scale Bogie

For Senior Project, we focused on researching what sensors and modules will be useful to obtain the design specifications for the full scale model. I started researching various electrical hardware such as optocouplers, relays, and switches to determine what plausible configurations there are for the system. The project is still in early project development where I have to research along with my team members system hardware so we can create a system that accomplishes what we want it to do but keep it clean and modular. The ability to switch out faulty wires, Arduinos, and other electrical components on the fly will save us a lot of time during debugging and prototyping. Labeling all the parts will help us figure out what pieces could be malfunctioning if the bogie is not performing the way it is intended. I will continue to research further electrical components to create a proper block diagram that will accomplish at least our motor system and after the motor system is working, the next step will be to install encoders and other location devices so the bogie will be able to traverse the track in a precise and accurate manner.

Senior Project Update

I have been slacking on these blogs and in an attempt to catch up and explain what has been going on on my side of researching and looking for ways to contribute to the project. This blog will encapsulate the work I have done this past month. I will try to keep everyone updated with on how my contributions can help advance this project to the next level and understand more the inner workings of this project to better help manage and develop the Spartan Superway.

This past month has consisted of deep research into possible configurations of wiring the motors. I have been researching and learning different wiring techniques and how different appliances and parts work in tandem with one another to obtain our functional specifications of the bogie. With the bogie having to move forward and backward at 2 MPH, how fast we reach that mark and what we are using to control it become a very important to continue discussing with my team as well as thinking about how everything else is going to connect with wayside power and the motor team. With the motor team introducing brush less hub motor, I have to study how they operate. The main difference between a traditional DC motor and a BLDC motor is that the BLDC motor using magnetic fields and coils to rotate based on the fields induced in the motor. This is how we will begin to control the motors and how we can vary their speeds to get our targeted numbers. More research and rapid prototyping will be coming in the near future due to the nature of our project. Being able to quickly test a small scale configuration and seeing what works and what needs to be reconfigured will be a large part of our work this semester. Once a working small scale prototpye of our control system is in place we will be able to obtain higher grade materials that work with the higher voltages and currents that will be present in the full scale model. In the next few weeks, using our design and functional specifications, a working small scale model will be able to be implemented with the help of the motor and wayside power teams.

Thank you for reading and will keep you posted of future findings. If you would like to see the controls team progress so far please see our team blog for full scale controls.

Introduction

Hello,

My name is Justin Guro. I am currently a fourth year engineering student with majors in Mechanical Engineering and Computation Mathematics. I enjoy learning new aspects of the engineering and mathematical fields and looking into new ways of solving complex problems. I enjoy playing sports in my downtime and am looking forward to contributing to the Spartan Superway.

The Spartan Superway seems like a great entry into the field of controls with I am pursuing. With the amount of work that has been done on the project already, I feel like it is a great opportunity to gain valuable experience while contributing to a diverse project that has been going strong the last several years.