Mini Sumo Robot Competitor

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What is a Mini Sumo Robot?

A fully autonomous robot that competes against other robots in a head-to-head match to push the other out of the Dohyo without weapons.

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Dohyo

The dohyo is the battlegrounds of the competition. It is a circular shape with shikiri lines (starting lines). Some other details include:

  • Height: 2.5 cm
  • Diameter: 77.0 cm
  • 5cm white border
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Robot Requirements

Our robot is completing in the Mini Sumo Class. For more information about the rules and regulations about the project click HERE

  • Max Size: 10cm x 10cm
  • Max Weight: 500g

Our Robot

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Microcontroller

Teensy LC, this microcontroller features an ARM Cortex-M0+ processor, 8K RAM, 12 bit analog input and output, SPI, I2C, with a total of 27 I/O pins

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QTR-1A Reflectance Sensors

The QTR-1A reflectance sensors consist of a single infrared LED and phototransistor pair which is useful for line sensing and edge detection. We chose this type of sensor due to its small size which allowed us to use multiple of them. We placed three reflectance sensors on the bottom PCB of our robot in order to detect the white line that indicates the edge of the dohyo. These sensors are oriented in such a way that two are placed on the front and one is placed towards the back of the robot. Once the white line is detected the robot responds accordingly by reversing direction to move away from the edge of the dohyo.

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Time of Flight Sensors

We chose to use Time-of-Flight sensors because they provide us with useful information regarding the distance to our target. The sensors have a 25° beam angle and since we have chosen to use 3 of these sensors on the front of our robot, the end result is a wide range of view which leads to effective opponent detection. Once the opponent is detected in front of us, we quickly accelerate towards it in order to push it out of the dohyo. The sensors are all connected to our microcontroller and use the I2C protocol to relay data.

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Motors and Motor Encoders

One of our robot's unique characteristics is the size of the motors being used. Since we had to meet the size requirement of 10cm x 10cm for the contest, we placed the wheels (and hence the motors) in an offset position. The type of motor that we chose meets our torque requirements and can reach a peak of 1030 RPM. Each motor contains a quadrature encoder which consists of a Hall-effect sensor that can provide feedback as to how fast our robot is moving and in which direction. We used this information in a feedback loop in order to correct any mismatch in wheel speed between the two wheels on our robot.

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Motor Driver

Due to the size and capability of our motors we needed hefty motor drivers in order to effectively drive them. In our design we utilized two single continuous motor drivers that each support a maximum current of up to 13A continuous and 30A peak (for 10 seconds). These motor drivers have the ability to bi-directionally control our motors through the use of PWM.

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Power

Our main power source is a 4S 14.8V battery with 450mAh capacity. It directly powers our motor drivers and is also fed into a regulator circuit with provides an output of 5V. This 5V rail powers our microcontroller and sensors.

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Wheels

Our performance goals rely heavily on torque and traction so we decided to create our own custom wheels to provide us with the traction necessary to win in the case of a pushing match between our robot and the competitor's. By creating custom wheels we were able to appropriately size them and by using silicon and rubber we were able to make them sufficiently sticky.

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Hardware Block Diagram

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Software Flow Chart

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Team Members

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Jaclyn Penano

Computer Engineer
Website Designer and Software Programmer

Adrian Fernandez

Computer Engineer
Software Progammer and Editor

Travis Tkachuk

Electrical Engineer
Repository Manager and Mechanical Designer

Michelle Hernandez

Electrical Engineer
Project Manager

Mohammad Alsehali

Electrical Engineer
Parts Manager

Faisal Alghamdi

Electrical Engineer
Power Specialist

Patrick Gerardo

Computer Engineer
Software and Secretary

Budget

Total Spending: $371

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