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Welcome to Part Two of CE Bot. We will continue the discussions regarding the CE Bot project in this thread.
For previous discussions, please refer to Part One: CE Project: CE Bot
Introduction of CE R3 CE R3(formerly CE Bot) is a project regarding the design and construction of a modular robotic system that can perform various research missions.
Its first mission is that of a semi-autonomous rover. It will consist of an array of sensors, mainly to detect it's surroundings and collect data for processing purposes. Data will be wirelessly transmitted to a host computer located a distance away. The design of rover will be modular to allow for interchangeable components and ease of future upgrades.
For more information on the CE Bot, please refer to the CE Lab website: CE Bot (CE Lab Projects)
Summary of previous discussions
Formulating objectives;
Discussion opens up for defining mission and roles for a robot. A laptop would be utilized as the pre-processing unit and robot controller. It is proposed that the mission will involve data collection and rescue, amongst others. A host computer will be used in the vicinity to act the main processor of data as well as external control. To allow the robot to cater with vast types of applications, the robot will be designed modularly.
Communications;
Discussion leads to methods for processing data and which wireless technology to use to transmit data. 802.11 is proposed.
Chassis/Locomotion;
Various chassis and locomotive options were discussed, such as tracked and wheeled. Some CAD designs have been uploaded for conceptualization of ideas.
Things to discuss in Part Two:
Further Robot Chassis Design
Sensors
Simulation software tests
Python tests
Wireless connectivity tests
Draft proposal for funding
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As of August 6th 2008, still needs updating. Will add more things soon.
Wow. . .a whole new thread! Yay!
Like I said, I'll get on those designs very soon. I will be gone later on today, Saturday, and Sunday, so no designs then. I leave at 4:00 PM my time, which is in 3 hours. Sorry I haven't come up with anything lately. . . I've got artists block. It sucks.
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I reject your reality and substitute it with my own. . .
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Just a real quick note before I forget, as we were chatting about the pros & cons of battery vs. gas power supply, how to provide drive for the bot and solar cells to recharge or linking the brakes into alternators to provide electrical charge. Personally I think awd via chain or tracks is best due to simplicity, weight savings. dwd, direct wheel drive can also be achieved though would add to weight. I'll talk more about then later.
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"Now Nortons and Indians and Greeves won't do,
Ah, they don't have a soul like a Vincent '52"- Richard Thompson
"if you look for the bad in mankind, expecting to find it, you surely will."-Abraham Lincoln
-------------------------- john@crazyengineers.com gohm@crazyengineers.net
Just a real quick note before I forget, as we were chatting about the pros & cons of battery vs. gas power supply, how to provide drive for the bot and solar cells to recharge or linking the brakes into alternators to provide electrical charge. Personally I think awd via chain or tracks is best due to simplicity, weight savings. dwd, direct wheel drive can also be achieved though would add to weight. I'll talk more about then later.
Thanks for that, gohm. Looking forward to see more details later! Could you sketch how you'd implement the awd via chain?
Also, I looked into your .89 nitro idea. They are called "Glow Engines", yes? They seem to be pretty cool, hehe. What are their fuel consumption like? Would you require a large fuel tank? Lets say that the rover will operate for around 1 hr. Max speed will be 4-5 km/h. I'm not too sure of the weight.. 20 kg maybe?
Back to using DC motors, here's some plus points to consider:
1- Runs on electricity. Rover will have one common power source to power all subsystems.
2- relatively small size. Can have multiple motors to implement the "direct wheel drive". If one motor fails, the rest can continue running. Thus, redundancy is assured.
3- Easy to swap DC motors depending on how its mounted.. only need to resolder the wire connections.
4- Very accurate control via programming.
5- When rover is stationary, DC motors will not consume any electricity. Its pretty much "power on demand".
Some bad points
1- even small, a collective weight of 4 DC motors might be heavy.
2- Will consume a lot of electricity if rover is going uphill or struggle over terrain.
3- need to expand battery size and/or amount to accommodate motors.
Hands down, I am in for building a rover something that is at least a tad-bit in league with any of the described rovers on the Updated Case studies page on celab.tk website (above). These are robo's from NASA or the Department of Defense.
Take your time to read about each of them. And also watch the videos. We will learn something about tracked system or the AWD and also the awesome system of all terrain wheel types. Pretty good.
Hands down, I am in for building a rover something that is at least a tad-bit in league with any of the described rovers on the Updated Case studies page on celab.tk website (above). These are robo's from NASA or the Department of Defense.
Take your time to read about each of them. And also watch the videos. We will learn something about tracked system or the AWD and also the awesome system of all terrain wheel types. Pretty good.
All of these with the exception of the autonomous drilling bot, are using the chain. I agree with Gohm on the use of either chains or tracks instead of individual motors for each wheel. His idea of 0.89 nitro is also quite good. It is not very bulky, quite powerful for its size, providing good speeds to RC cars in which it is used.
@Ash:- Yes they are called glow engines also as they use glow plugs instead of spark plugs to ignite the fuel. The fuel used is called glow fuel which is either methanol or nitromethane. You can refer this link for more info Glow plug (model engine - Wikipedia, the free encyclopedia)
development of technologies like brushless motors and lithium polymer batteries. These allow electric motors to produce much more power rivaling that of fuel-powered engines. It is also relatively simple to increase the torque of an electric motor at the expense of speed, while it is much less common to do so with a fuel engine, perhaps due to its roughness.
The main reason Glow engines cannot be used is because its practically impossible to control the torque (and speed in large variations). This is possible and efficient in electric motors. Plus we will be running our bots for hours and may also use solar power for longer uses, not 10 or 20 minutes as is possible with a glow engine used in RC cars.
#1 
12th July 2008, 12:25 AM
CE Project: CE Bot [PART TWO] 
