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Autonomous Sumo Combat Robot with Pneumatic Flipper - How to

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Picture of Autonomous Sumo Combat Robot with Pneumatic Flipper - How to
SumoBot Flipper Down.png
SumoBot Top.png
Arena.png
This Sumo Bot was designed, built, programmed and tested over a 12 week period for one of my final year engineering classes. The aim was to design and build a lightweight fully autonomous sumo fighting robot for an in class Sumo Bot competition. The robot was required to push, lift or flip the opponent’s robot out of the arena.

There were two physical restrictions which the sumo robot must abide by. The robot must weight no more than 1000g and is required to fit within a 200mm x 200mm x 300mm (WxLxH) measuring box. Other restrictions included the robot had to be completely autonomous with zero human interaction, must cost under $150 AUD (not including the micro-controller) and the robot must begin each round in the same orientation in which it was place in the measuring box. 

We were given the option for adding a lifting/flipping system to our robots. I knew it would require a lot more work but I couldn't resist the temptation of adding a "weapon" to the bot.

The Arena
The arena was circular with a diameter of 1.54m with a matt black surface and a 2cm wide white line around the perimeter.

 
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Step 1: Components

Picture of Components
This section contains a list of items required in making the Sumo Combat Robot. It has been split into two parts, the first is a list of items which were purchased and the second is a list of items which were scrounged from previous projects. All purchased items contain a link to the suppliers website.  
 

Cost Items

2 x Motors 47:1 Metal Gearmotor 25Dx52L mm HP

1 x Motor Controller 10A H-bridge Dual DC Motor Driver Controller / High-power Strong braking

4 x Pulley Hub FingerTech Timing Pulley 26T 

2 x Belt FingerTech Timing Belt 276mm (92T) 

4 x Wheels Dave Brown Lite Flite Wheels 2" 

4 x Line Sensors TCRT5000 Module Line Tracking Photoelectric Sensor

3 x Sonar HC-SR04 ultrasonic sensor distance measuring module

1 x Battery ZIPPY Flightmax 1300mAh 3S1P 15-25C 

2 x Pneumatic Cylinder Air Actuator 25mm  

1 x Tank 100CC Air Cylinder 

1 x Pneumatic Switch Servo Operated Air Retract Actuator (Air up/Down)  

1 x One way valve One Way Air Refill Valve 

1 x Tubing Air retract pipe D3x1.7mm x 1m 

1 x Indicator LED ShiftBrite 

 Non-Cost Items                                                                                    USE
Aluminium Sheet  50cmX50cmX1mm________________________ Chassis
Aluminium L-Section _____________________________________Chassis support
Super Glue____________________________________________Sensor mounting
Tarzan Grip___________________________________________ Wheel to pulley mounting
Pop Rivets____________________________________________ Chassis assembly
Double Sided Tape______________________________________ Insulation, component mounting
Heat Shrink____________________________________________ Insulation
Connecting wires_______________________________________ Interface with components
Power Switch__________________________________________ Main power cut-off
Selection Button_________________________________________ To select between attack/evade modes
Solder_________________________________________________ Component wire connections
ATMega128 Microcontroller ________________________________Sumo robot controller
10 wire IDE Plugs________________________________________ Connect sensors to the microcontroller
Microcontroller power plug_________________________________ Deliver power to the microcontroller
Zip Ties________________________________________________ Hold pneumatics in place and tidy up electronics
Elastic Bands___________________________________________ Support pneumatic cylinder
M3 cap screws_________________________________________ Hold front wheel pins in place
Transistor______________________________________________ Switch motor controller on and off
Resistor_______________________________________________ Limit current to transistor
9g Servo_______________________________________________Control pneumatic switch
Female Crimp Pins_______________________________________ Connect microcontroller to the motor controller
Crimp Pin Housings______________________________________ Insulation over crimp pins
Electrical Tape__________________________________________ Insulation
0.8mm Steel Wire________________________________________ Link servo to the pneumatic switch
6mmX6mm square bar ____________________________________Flipper arm connection
Aluminium Sheet 20x15x3mm_______________________________Flipper arm

Step 2: The Sensors

Picture of The Sensors
Ultrasonics.png
Ultrasonics angles.png
Line Sensors
The boundary of the arena is identified by a distinctive 2cm thick white line. This white line was used by the sumo robot to detect where the edge is located. The white line is detected using 4 digital IR line sensors. This sensor was chosen due to its integrated comparator circuitry which converts the output into a digital signal. The benefit of the digital signal is that it is simple to interface with and the microcontroller is able to respond faster to line detection. 

Name: TCRT5000 Module Line Tracking Photoelectric Sensor Comparator 
Weight: 1.1g
Max Dimensions: 10.6x34.7x9.45 (WxLxD)
Interfacing Method: 3 pin interface, VCC, Output and GND.
Power Supply: 5V DC
Output Current: 1mA
Effectual range: 0.2 mm to 15 mm
Cost: $1.89

Connection and Power:
TCRT5000 Module Line Tracking Photoelectric Sensor Comparator is powered by 5v DC using its VCC and GND pins. This power is delivered through the voltage regulator built into the ATMega128 microcontroller board and by the 11.1v 1300mah lithium polymer battery. The output pin on the line sensor delivers a low level signal when over a black line and a high level signal when over a white line. Therefore, the sensor can simply interface with the microcontroller through a single digital input pin. An electrical connection schematic is given later.  
The digital line sensors have been place in front of the front wheels and near the rear of the back wheels. This allows detection of the arena’s white boundary line while moving in all directions, and signals to the robot that it is at the edge and need to move away. The sensors were chosen for their small size, lightweight and cost effectiveness.


Ultrasonic Sensors
For object detection ultrasonic sensors were chosen for their ability to detect objects in close proximity as well as from the full diameter of the arena (~1.5m). The ultrasonic sensors selected are lightweight, simple to interface with and inexpensive.

Name: HC-SR04 Ultrasonic Range Sensors 
Weight: 8.2g
Max Dimensions: 45x20.6x15 mm (WxHxD)
Interfacing Method: 4 pin interface, VCC, Trigger, Echo and GND.
Power Supply: 5V DC
Quiescent Current: <2mA
Effectual Angle: <15°
Ranging Distance: 2cm – 500 cm
Resolution: 0.3 cm
Cost: $2.58

Connection and Power:
The HC-SR04 Ultrasonic Range Sensor is powered by 5v DC using its VCC and GND pins. This power is delivered through the voltage regulator built into the AtMega128 microcontroller board and by the 11.1v 1300mah lithium polymer battery.
The HC-SR04 interfaces to the microcontroller through its Trigg and Echo pins. Each of these pins are connected to one of the digital IO pins of the microcontroller. An electrical connection schematic is given later.

Acquiring a range reading involves the following process: 
    1. 10μs pulse is sent to the trigger pin
    2. Ultrasonic sensor outputs eight 40 kHz ultrasonic pulses
    3. Detects the echo back.
    4. Measured distance is proportional to the Echo pulse width
    5. Distance calculated by the formula: Distance = ((Duration of high level)*(340m/s))/2
    6. If no obstacle is detected, the Echo pin will give a high level signal for 38ms

This process is repeated each time a sensor reading is required. The AVR C code is given later.  
The ultrasonic sensors have been positioned for maximum effectiveness and coverage. Each sensor has a detection angle of 15° from its centreline each way. The maximum range of the selected ultrasonic sensor is 5 meters, due to the size of the arena this was limited in software to only look for objects within a 1.4 meter range.

Step 3: Motors and Motor Controller

Picture of Motors and Motor Controller
Motor Controller.png
Motors
Speed
The target speed of the sumo robot was 1m/s.
Using the equation, Speed = distance/time , the robot covers the diameter of the arena, minus the length of the robot, in just over a second. This speed is ample for the robot to catch opponents and evade when necessary.

Torque
The greater the torque the larger the robots pushing power, therefore the more torque which can be put into the system the better. However, it has to be noted that the torque is transferred to the ground through the wheels, and for that reason the wheel choice is also vital in generating maximum pushing force. Many different motors were considered, each with different torques and voltages. Additionally a range of wheel diameters were used to select the right motor and wheel combination to achieve maximum torque with a speed of ~1m/s.

The motor choice was the 47:1 Metal Gearmotor 25Dx52L mm HP from Pololu , with 51mm (2") foam rubber wheels. Each motor generates 4.5kg of pushing force at the ground. This results in a total of 9kg of total pushing which should be sufficient to push around any 1kg robot.

Traction
To generate the maximum traction from the motors, a belt drive system is used between the front and rear wheels. This addition doubles the contact area with the arena floor, resulting in a greater pushing power.


Motor-Controller
The motors are controlled by a dual H-bridge style motor controller with PWM inputs enabling variable speeds. The motor controller can control the speed and direction of the motor by receiving input commands from the microcontroller. The controller is capable of supporting voltages from 6v to 36v and a continuous current of 10A (peak 60A). It consists of two half-bridge driver chips and low resistance N-channel MOSFET’s. The two half-bridge driver chips make losses due to the MOSFET switching minimal.

The control pins on the motor controller include 2 direction pins, one for each motor, when high the motor spins forward and when low motor spins backward. It also contains 2 PWM inputs, 1 for each motor, which take a 1kHz to 100kHz pulse frequency to control the motor speed. Setting the PWM pin to low applies the breaks to the motor for stopping.

Step 4: The Flipper System

Picture of The Flipper System
Pneumatics
The flipper has been designed to penetrate under an incoming robot then activate. The end of the flipper is within 0.5mm of the ground, which allows for penetration under most opponents. The actuators chosen for the flipper mechanism are micro-pneumatic rams.

Pneumatics are extremely powerful for their weight, and are the perfect choice for this task. The force generated by a single pneumatic ram was found to be insufficient to effectively flip an opponent, therefore dual rams were used to increase the lifting power of the flipper. The rams have a stroke length of 25mm, which when coupled with the flipper design generates enough height to overturn an opponent. The components of the flipper system are shown in the image.

The flipper is activated using range information gathered from the two front ultrasonic sensors. The compressed air is stored in a 100cc cylinder. A compressor is used to pressurise the system to 115 psi. The pneumatic rams are controlled by a servo operated pneumatic switch; a schematic of the pneumatic system is given later.

Step 5: The Microcontroller and Indicator LED

Picture of The Microcontroller and Indicator LED
Microcontroller
The microcontroller used was the ATMega128, programmed in C using AVR studio 5. This microcontroller has a 16Mhz processor, and a large number of IO ports which is sufficient for interfacing with and controlling the sumo robot. However an Arduino could also easily be used.

Indicator LED
A RGB LED is used to indicate to the user which mode the robot is currently in. The LED is called a ShiftBrite and is available from Pololu. It is capable of producing any colour by mixing the red, green and blue light at varying intensities and combinations. I used blue to show the robot is in mode selection mode, red for attack mode and green for evade mode. The LED is also pulsed at varying rates to show initial start delays.

Step 6: The Chassis Design

Picture of The Chassis Design
Cad Back.png
CAD Frinforcement].png
CAD Stencil.png
The Sumo robot was designed in a 3D computer aided design software, incorporating all of the sumo robot’s components. This allowed the design to be easily altered and manipulated to take full advantage of the size and weight restrictions. 

The chassis is constructed from 1mm sheet Aluminium with thicker L-section Aluminium reinforcement. The external shell of the chassis has been designed to be folded from a single sheet of 1mm Aluminium and held together by the reinforcing members and pop rivets.
The chassis cut out pattern is shown above and given later.
This final chassis design has been chosen for its ability to deliver high strength and rigidity in a lightweight unit. 

The design iterations can be seen in the following clips. 

Design MK2

Design MK3 


Design MK4 (Close to final design - however side ultrasonic sensors were removed)

The positioning of the internal components within the chassis can be seen in the above video. The motors have been positioned so the wheels protrude back past the rear of the robot, this allows for continual traction if accidental mounting of another robot’s ramp occurs. Due to the battery being the heaviest component, it has been placed centrally over the wheel base to disperse its mass evenly and generate maximum traction.  

Due to the differential drive system, the bot is capable of on the spot turning when the wheels are spun in opposite directions . Therefore the effective turning radius is 0.

PDF's of the chassis components are be supplied at the end of this instructable. 

Step 7: The Flipper Design

Picture of The Flipper Design
CAD Flipper Down.png
Sectional view.png
Sumo front flipper up.png
The flipper has been designed to generate 109mm of vertical lift, which with the speed and power of the pneumatic system, is enough to overturn an opponent.

The basic shape of the flipper arm was designed to fit within the chassis and have zero ground clearance at its tip. 

The Flipper is cut from 3mm Aluminium in two halves. The two halves are then joined by (6)   6mmX6mmX22mm square bars.
Each bar had a 3.3mm hole drilled into each end to accommodate a 3mm rivet.

The two halves were then joined with the rivets to form the finished flipping arm.

The cross sectional view of the sumo bot shows how the pneumatic rams were attached to the flipping arm. The pin which holds the end of the rams in place is the scrap shaft off one of the 3mm rivets.  
  

Step 8: Assembly Pictures

Above are pictures of the finished assembly from various angles. 
It can be seen that the sumo bot chassis is held together by a large number of light weight pop rivets.

The final assembly was extremely rigid and strong. It could comfortably support my weight (~70kg) without plastically deforming.


 

Step 9: Testing the Flipper

The abilities of the flipper was tested initially on various static objects, then on a 1kg opponent.

The flipping system was found to be fast, powerful and could easily flip most opponents. Even if the flipper was unable to flip an opponent, it was still able to lift it up which results in less traction for the opponent and more traction for my sumo bot.    

This video shows the 3 possible states of the flipper
 

In arena test 1


In arena test 2

Step 10: The AI and Component Interfacing Code

Picture of The AI and Component Interfacing Code
Attack Mode.png
Evade Mode.png
For the robot to be able to seek out and attack the opponent’s machine seamless interfacing with the sensors is required. Moreover the robot must be equipped with enough artificial intelligence to cope with the situations which may occur within the ring. The ring has the added benefit of being a closed environment, this results in fewer possible situations.
Evading another robot has the same requirements as attacking. One additional extra which is required for evasion is either a reverse or side facing sensor to keep track of the pursuing robot. Alternatively the robot could move in reverse.  
The autonomous abilities of the sumo robot are only required to be fairly basic. The control code involved in creating the robot’s autonomy should be able to cope with the readings from all of the on-board sensors and respond to threats in a quick and efficient fashion.
To enable the robot to perform the required tasks of autonomous attacking and evading a reactive code structure was implemented. This resulted in an agile robot which can respond quickly to an opponent’s actions.


When first switched on the sumo robot enters a mode selection state, identified by the flashing blue indicator LED, this state lasts for 5 seconds. This state allows the user to select between an Evade mode or an Autonomous Sumo Competition / Attack mode.

The robot automatically enters the evade mode if the user does not press the red button during the mode selection state. Once in evade mode the indicator LED will flash green, showing that the robot is waiting for its start command.

To select the Autonomous Sumo Competition / Attack mode the user must press the red button during the mode selection state. In the Autonomous Sumo Competition / Attack mode the LED will flash red, indicating the robot is waiting for its start command. Once the start button is presses the respective LED colours will flash fast for 5 seconds, during this time the user must move more than 1.5m away from the arena. The LED will then become the solid colour and the robot will begin its selected mode.

Evade Mode Goal
The main goal of the evade mode is to avoid contact with a pursuing object, while maintaining within the arena’s boundary. This is be achieved by locating the object then tracking it with the two front ultrasonic sensors. The pursuing object is tracked on the spot until it gets within 50cm. The sumo robot then moves in reverse trying to maintain the 50cm distance. The robot keeps moving backwards until it contacts the white boundary line, at which point it rotates away from the pursuing object and moves back towards the centre of the arena. The robot then detects the object again and the process is repeated. A flow-chart of the evade mode is shown in the images.

Attack Mode Goal
The goal for the Autonomous Sumo Competition / Attack mode is to push or flip the opponent out of the arena, while remaining within the arena. The sumo robot scans for objects using its ultrasonic sensors. Once an opponent is found the robot rotates until the opponent is visible in its two front sensors. Next, it rams forwards and tries to push the opponent out of the arena. The flipper then activates given the following conditions:
     1. The opponent is visible to both the front ultrasonic sensors
     2. The opponent is within 10cm
Unless both of these conditions are met, the flipper will not actuate. Once the flipper has actuated, the robot continues to ram forward, then lower then flipper after 0.75 seconds. The process is then repeated if required. A flow-chart of the Autonomous Sumo Competition / Attack mode is shown in the images.          


As stated earlier, both the evade and attack functions of the sumo robot are purely reactive. If an object is detected, an action is performed. A reactive method was chosen due to its quick response time, effectiveness and ease of implementation.

Interfacing With Ultrasonic Sensors 
This tutorial will guide you though how to interface with the HC-SR04 ultrasonic sensors. 
Interfacing Ultrasonic Rangefinder with AVR MCUs – AVR Tutorial

I
nterfacing with the IR Line Sensors
The line sensors can simply attach to a digital input of the AtMega128 MCU. Then the MCU can read the sensors current state.

Interfacing with the ShiftBrite
The ShiftBrite was controlled using a method called bit banging. The attached document contains working example code for interfacing with the ShiftBrite.

Interfacing with the Motor Controller
The motor controller only requires digital high/low direction signals and PWM signals. Both of which a simple to implement with the AtMega128.  

Step 11: Schematics and Part Drawings/Stencils

Picture of Schematics and Part Drawings/Stencils
Pneumatic Schematic.png
Electrical Connection Schematic (Wiring Diagram)
The wiring diagram for connecting the 4 line sensors, 3 ultrasonics,  ShiftBrite LED, switch, Button, motor controller and the servo for the pneumatic system is shown above. 

Pneumatic System Connection Schematic
The connection diagram for piping the pneumatic system is also shown above.

Fabricated Parts Drawings
The attached drawings of the sumo robots fabricated parts are all at a 1:1 scale. 
These parts can be printed off, glued to the aluminium sheet or L-section and then its simply a matter of cutting along the lines. Alternatively the main chassis part could be cut out using a CNC mill or laser cutter.

Step 12: Overall Performance

The final cost came in a about $149, with a total weight of 999.4g and dimensions of 200x200x75mm.
I was able to get my weight and dimensions so close to the mark by utilising weight calculation software incorporated into the 3D modeling program.  

On the competition day the sumo bot performed very well, taking out the competition in most battles.
The flipper worked exactly as designed and managed to flip multiple opponents out of the arena.
However during some of the later rounds, a small leak occurred in one of the seals in the pneumatic switch which resulted in pressure loss. This issue can be simply fixed using an o-ring sealant.   

My sumo robot won 1st place in the competition. The video below shows my robots competition highlights. 

 
 
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FLIPminoman2 years ago
Amazing! One of the few instructables worthy of being on this website! I love it!
kmmarlow (author)  FLIPminoman2 years ago
Thanks mate, I had a lot of fun working on it.
I will be uploading some of the other project I've been working on when i get time.
Please vote for me in the competitions.
Thanks again
DuyT11 month ago

Can you give me the file CAD of this robot ???? :)

kmmarlow (author)  DuyT11 month ago

From the PDF files it is very simple to map and extrude the bot.
A lot of the internals are also already available on GrabCAD.

Best of luck!!

DuyT1 kmmarlow1 month ago

I try to design the sumo robot with the MICA and in Vietnam we need the Solidwork files to make it so can you give me the solidwork file :)

Thanks you :)

DuyT11 month ago

This is my email: duydedu1801@gmail.com

leadzeplin5 months ago

code?

kmmarlow (author)  leadzeplin5 months ago
The code can be simply derrived from the details and charts provided in "STEP 10: THE AI AND COMPONENT INTERFACING CODE".

but iam too lazy to code that

Is it possible to add saw blades that come out the bottom?

lot of competition have it banned

kmmarlow (author)  Inventors Unite2 years ago
Anythings possible, however keeping it with the flipper and adding in a saw blade would put it over weight.

tell me is it strong to throw 3kg zumo bot

teknohawk4 months ago
This is absolutely amazing! How did you ever learn to do something like this?
leadzeplin5 months ago

code?

leadzeplin5 months ago

code?

leadzeplin5 months ago

code?

leadzeplin5 months ago

code?

rania_asfour7 months ago
awesome robot (y)
I am going to make it and I am going to start this weekend ..
but in my competition the robot must push 3kg .. so what type of motors and battery I should use ??
thank you :) .
jjjohnjoel10 months ago

HELLO, I LIKE YOUR PROJECT..... AND I AM GOING TRY TO DO IT ......

BUT THE PROBLEM IS THAT ALL THE COMPONENTS ARE NOT AVAILABLE TO ME SO I HAVE TO USE SOME ALTERNATIVES FOR THESE COULD U PLEASE SUGGEST SOME FOR THE BELOW PRESCRIBED ONES

Motors 47:1 Metal Gearmotor 25Dx52L mm HP

I CAN GET MY HANDS ON A

34:1 AND 75:1 MOTOR OF 6 V ...WHICH SHOULD I USE......

AND CAN I USE A 9 V NON RECHARGEABLE BATTERY INSTEAD

ALSO WOULD YOU PLEASE PROVIDE ME A SKETCH FOR CONSTRUCTION OF THE FLIPPER .......

AWAITING YOUR REPLAY

kmmarlow (author)  jjjohnjoel10 months ago

Hi,

Great to see your going to build it :) Make sure you post pictures/links to your work.

The 34:1 will make your bot move faster with less torque, the 75:1 will move slower with greater torque.
both will supply enough torque to push more than a 1kg opponent bot. I would go for the 37:1 motors.

the 9v battery will work but will probably run out of juice pretty quickly. THis was the reasion i went for a LiPo battery.

I dont have a picture of the flipper handy however the in the stencils provides it has the outline.
What i did then was cut 7 lengths of solid 7mmx7mm aluminium rod to length(so the flipper fits inside the front gap of the robot.)

Then i drilled out each end of the 7 cut rods

Then pop riveted them onto the flipper arms. (in the spots marked on the stencil)

Good luck mate

THANKS FOR THE REPLY

HOW CAN I USE AN ARDUINO INSTEAD OF ATMEGA128

IF POSSIBLE COULD YOU PLEASE SEND THE CIRCUIT AND THE NECESSARY PROGRAMME FOR THIS IF POSSIBLE TO MY PERSONAL MAIL......

HOPE U WILL SEND IT QUICK

I HAVE TIGHT SCHEDULE HAVE TO FINISH THIS BY TOMORROW IF POSSIBLE ...

MY MAIL: joeljohnec@gmail.com

kmmarlow (author)  jjjohnjoel10 months ago
Hi,
sorry I won't be able to do that. I'm not near my computer for the next few weeks.
its basically the same code and wiring for the arduino and the mega (just a change of io pins and no need to control specific registers. )
good luck mate.
kmmarlow (author)  jjjohnjoel10 months ago

Hi,

Great to see your going to build it :) Make sure you post pictures/links to your work.

The 34:1 will make your bot move faster with less torque, the 75:1 will move slower with greater torque.
both will supply enough torque to push more than a 1kg opponent bot. I would go for the 37:1 motors.

the 9v battery will work but will probably run out of juice pretty quickly. THis was the reasion i went for a LiPo battery.

I dont have a picture of the flipper handy however the in the stencils provides it has the outline.
What i did then was cut 7 lengths of solid 7mmx7mm aluminium rod to length(so the flipper fits inside the front gap of the robot.)

Then i drilled out each end of the 7 cut rods

Then pop riveted them onto the flipper arms. (in the spots marked on the stencil)

Good luck mate

ckoufalia1 year ago

nice job i have a question i read somewhere that all sumobots is needen to have an IR kill switch what is this thank you

Sory for my english

kmmarlow (author)  ckoufalia1 year ago

Not exactly sure what they would have meant by an "IR kill switch". Ive used an 433Mhz wireless kill switch before which 'kills' the bot.

I think they was to be able to stop the bot without having to touch it.

thank you a realy helpfull answer

прикольная хреновинка =)

I have been working on mine for a college competition for one of my courses. So far it works great. I wish we could use sonar rather than the IR LEDs and detectors.

Robot.JPG
kmmarlow (author)  invisiblelight3861 year ago
Nice looking bot! In some cases IR world better than sonar. You could try and convince your lecturer to let you use a laser pointer and the same detector (you'll get pinpoint accuracy and a longer detection distance)

Another thing, if you spend a couple hours polishing up your bot it will make it difficult for the other bots to detect yours. .. Depends how sneeky you want to be.

Good luck in the comp!

I'm going to try and make a spring loaded flipper that would be contact activated. There is one sumobot that is almost invisible to my sensors, and I could use a new tactic.

kmmarlow (author)  invisiblelight3861 year ago

you could easily integrate a contact sensor (micro switch) into a design with any ling of flipper system.

If you used a microswitch on the front of the flipper which activates it when touched.

Good luck defeating that pesky opponent :)

M3RCIL3SS1 year ago
Hey what code did u use, please help, if u could give the code that would be cool
it will be powered by arduino
kmmarlow (author)  M3RCIL3SS1 year ago
Hi, The code i wrote was for implementation on a atmega 128 AVR micro-controller so it will not be very helpful for the arduino.

Step 12 of the I'ble has some flowcharts which accurately outline my method used for the AI and the logic for the Flipper control.

Hope that helps.
Message me if you need assistance with any specifics.
makesomeso1 year ago
i like your instructable very much and its cool. nice work. this is one of my favorite instructable.
aaron01271 year ago
Hey loved your ineluctable. My schools is entered in bots IQ. (battle bots) and we are doing a wedge design with a pneumatic flipper on the front like yours. I was wondering if you could give me some insight on how to do a good flipper.The bots can weigh up to 20 pounds. we are only allowed 8 cubic feet of at 150 PSI. Thanks and hope to hear from you soon.
kmmarlow (author)  aaron01271 year ago
Thanks, (Also sorry for the really late reply) For a ~10kg robot 150PSI is Heaps. Its more about the mechanical design of the flipper and the pneumatic ram itself than the pressure of the tank. (howerer all work together in making a good flipper)
Tool such as this http://www.engineeringtoolbox.com/pneumatic-cylinder-force-d_1273.html can help you get an idea of the 'full bore piston diameter' you require to achieve the force you need to lift an opponent. the larger the ' full bore piston diameter' the more force the piston will output, however increasing its size will also slow the flipping speed and use more compressed gas per flip.

The flipper should be as close to the ground as possible and when activated flip high enough or hard enough to roll the opposition over.

The basic principle of levers need to be considered "most flipping mechanisms will be "Third-order Levers". A good resource is http://www.engineeringtoolbox.com/levers-d_1304.html

Another option is to use a four bar linkage such as http://www.youtube.com/watch?v=JEA8dRkR0g4 Which lifts and pushes into to the opponent at the same time.

3D Computed aided design software such as google sketchup or SolidWorks are great for quickly looking at different flipper designs. Also lego technic is a valuable prototyping tool.

Any more questions just let me know.
Best of luck in the competition, and trust me, you will learn HEAPS for competing.


That's an awsome robot you got there!
kmmarlow (author)  gunnlaugursig1 year ago
Thanks it was great fun building it!!
dcruz131 year ago
Awesome project! this gave me a lot of ideas for my final year project, where I'm planning to build a sumo robot using fuzzy logic on its operative mode.

As I'm new on prototiping, wich softwares do you suggest to schematics simulation?
Did you used some simulation software for the robot, like "testing" its behavior like reallife?
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