After building a number of indoor robots, we decided to build an outdoor robot capable of traveling through rough terrain. We call it “Trekker.”
TREKKER ROBOT. Six wheels. Six motors. Batteries below deck. Electronics above deck.
First, we put together a six-wheel independent suspension with a separate motor on each wheel and large knobby tires. Each wheel moves up and down separately, which allows this little beast to climb up and over just about any obstacle (rocks, slopes, cats, whatever gets in its way). Here is a video of Trekker going over a large pile of books.
This is by far our funnest robot to drive via Remote Control, but this true magic of Trekker is his navigational capabilities.
We wired Trekker with a GPS chip and a tilt-compensated magnetometer (an electronic compass that works even when the robot is tilted). When Trekker first comes on, he automatically looks for and synchs with as many satellites as he can find in the sky (usually about 10-15). We programmed Trekker to determine his exact latitude and longitude position using the GPS as well as his directional orientation using the magnetometer. He then travels on his own to a series of latitude and longitude waypoints (that we get from Google Earth). Trekker’s navigational algorithm was one of our most ambitious software challenges to date. Our favorite test run is to put him in our backyard and give him instructions to drive around the big tree, down to the barn, drive around the goat pen, and return to us. He does it beautifully, all on his own, moving systematically from one waypoint to another. We also equipped him with a forward-facing sonar, which swivels back and forth on a pan servo, to avoid trees and other large obstacles along the way.
Trekker Robot - Top View - The white square in the middle is the GPS, which is used for navigation. When traveling between waypoints, the Longitude and Latitude display on the little LCD screen.
Trekker - Front View - This provides a nice view of the sonar at the front of the robot, which is used for obstacle detection and avoidance when traveling in automated mode. The magnetometer (compass) is mounted on a tall shaft at the back of the robot to keep it clear of interference from the other electronics, especially the radio.
This picture of Trekker's underside shows how each wheel connects to a separate motor (black t-shaped things). Each motor housing is on springs and swivels so that it moves separately from the other motors.
Thanks to the shock-absorbing independent suspension of each of its six wheels, Trekker rolls over pretty much anything
Software Modes
We programmed Trekker with a several different modes he can operate in:
- Navigate autonomously to a series of user-provided Longitude/Latitude Waypoints
- Roam autonomously using swiveling front sensor to avoid obstacles and find best path
- Radio Control (RC) – display commands and motor speeds on LCD
- Radio Control (RC) – display longitude, latitude, and heading on LCD
Technical Specifics
- Microcontroller: Arduino Mega
- IO Shield: DFRobot
- Motor Controller: Pololu Trex
- Radio Control Software: Beatty Robotics
- Automated Navigation Software: Beatty Robotics
- GPS: Parallax
- Sonar: Ping
- Sensor Servo: Hitec
- Chassis Parts: Dagu
- Magnetometer: Devantech
- Radio: Xbee
- Batteries: NiMH (electronics) + LIPO (motors)
I want to make this in my home. send me every little detail of making it.Send me the blue prints,software and everything i need to know about while doing this thing.plz Send me the details to my mail.
Are you serious? Stop asking questions like this. How about you take a few minutes, use Google, and try to teach yourself something instead of trying as hard as possible to have someone hold your hand while you make an exact copy of their work.
i have passion for robotics.i want to make robot like u have made.please send me files and instructions on my email khushmeetsingh1996@gmail.com
i have passion for robotics .please send me files and instructions on how u made it please send it on khushmeetsingh1996@gmail.com thanks
thanks for update….
but i want can u send me the files of your software of ur bot trekker…
Great work ! really fan of your robots!
Hi my name is Sheldon Kaye, I am a show manager at the new show APPCON. APPCON is a moilbe application developers conference & expo which is being help in Las Vegas, Nevada August 24-26.During APPCON we plan on holding a Hackathon competition where we envisioned moilbe developers programming robots to compete with each other in games or something similar.Your cell bots would be absolutely perfect for this competition, and I was hoping I could talk to you further about this opportunity.If this interests you please email me or call me at 702-450-7662 ext. 124Hope to hear from you soon!
Fantastic robot! I’m wondering whether the Wild Thumper Arduino Dual 15A DC Motor Controller would be as suitable for this robot? Also could a regular arduino work with this 6 wheeled chassis if you just wanted obstacle avoidance or remote control?
swhobbs: Thanks for the positive comment!
In answer to your questions: The Wild Thumper Motor Controller did not exist when we built this robot. But it would be totally perfect for this robot. In fact, the Wild Thumper motor controller was designed specifically for this chassis. We have bought one of the Wild Thumper controllers to play with, but we haven’t tried it yet. Regarding your Arduino question: You can use a regular Arduino for this sort of project. You don’t absolutely need the Mega. You could use an Uno or even a Nano. However, one of the reasons we used the Mega is because it has multiple dedicated hardware-based Serial ports, which makes serial communication much easier (which is good because we communicate with several of the components using serial communication). If you don’t use a Mega, then you need to do this using “Software Serial,” which is doable, but it ranges from mildly tricky to extremely tricky depending on the situation. Since building Trekker, we’ve done some Software Serial work on some of our other robots, and it is feasible, but it’s more challenging than using the Mega’s dedicated ports.
Hi, we are very impressed by your realisations and are actually working my daugthers and I on similar project (an environnemental explorer with a embedded webcam and sensors). We first thought of à tank module for the motor section, did you évaluate this option ?
We wonder wether also if an arduino mega would make the job with the remote control, the pwm, the sensoriel (temp, moist, light…) and the vidéo transmission?
Thank’s for your advice and it’s réally a good job!
Dominique
Hello, Dominique. Yes, we’ve done some work with tank treads. They are fun. But in terms of practicality, the tires and arrangement shown on Trekker are much better for traversing difficult terrain. And yes, the Arduino Mega would make an excellent controller for a robot. That is by far our favorite controller. We use the Mega to build all sorts of stuff. Yes, sensors for light, etc., are all achievable. Keep us posted and feel free to ask questions. We can help you design. You may want to check out the http://www.RobotShop.com (they have an English and French version). You may want to consider the DFRobot temperature sensor, light sensor, etc. There are many ways to do it, but this will make it easier.
Hi I would like to know, i am building a remote control rbot using the 6 wheel thumper,but buying the thumper controller is expensive,can i make use like you guys did ,of the arduino board. I might be able to get one here in Cape Town,can you perhaps help with wiring and schematics,software and how you did it it. Thanks would be appreciated.
Regards
Marinus
Marinus,
You don’t need the to use the Thumper Controller board to run this six-wheel chassis. Yes, you can use an Arduino board and a motor controller board (you’ll need both). But if cost is your concern, then the Thumper Controller’s cost ($74.95 at Sparkfun) isn’t too bad because you get both in a combined unit.