CE Project: CE Bot [PART TWO]

[gohm]

Been crazy with work so haven't spent much time on the Bot

[KINETIC_JOULES]

Wow, guys! I know I haven't been active lately! I've just got a lot of stuff going on right now. Please forgive me, as I am SO sorry. . .

[docel]

....everyone seems to be busy.....

[ash]

haha busy times, I suppose!

docel, what type of power supply do you recommend? We think of using Sealed Lead Acid for the motors. For the subsystems, we might either use SLA again, or try Lithium-Poly. We might need to boost up the voltage for the laptop system board.. they usually require 18V. Will need to verify with xhx though for his Acer system.

[docel]

1. ....in the long run, a Mini-ITX or Pico ITX board may be a good choice, rather than a Laptop.

2. Sealed Lead acid batteries will add 2.5kgs to the weight budget. It will need some good motors to move that load.

3. The Laptop is of choice due to the "All Systems Aboard". Unfortunately , the least prefered component of the Laptop is the most power hungry!!
4. The dual battery system is THE way to go, if brownouts are to be eliminated.

[xheavenlyx]

@Docel:

1. I dont know how I am agreeing but it seems to be a good idea to use another board that's SPECIFICALLY for mobile/embedded applications with more needed ports e.g: USB's and serials and PCI slots. Ash what do you think? But before we go further with Mini-ITX/Mini-ATX, we will do a small (very small) research on different available types/boards. And then decide determined by certain factors.

2. I dont know about Lead Acid. They do provide acceptable power/energy but the weight problem. We might have to comprise on one of the 2 factors! Lets see.

3.

the least prefered component of the Laptop is the most power hungry!!

Which component is leastprefered and most power hungry?

4. Dual Battry is extremely importtant! Its one of the golden rule in robotics!! We never mix high power analog consumption (motors) with high power digital consumptopn (laptop/sensors).

===========

I said I will be presenting the sesors prsentation. Its still under construction beacuse of my convocation (i recieved my college degree on 27th, shit I didnt tell anyone!! I will make a new thread :P )

[docel]

The "least preffered and most Power-hungry" ::
Display, CD-DVD drive, HDD, BTh/wifi/PCMCIA, lOW RAM.......
.....in that order.

Display and CD-DVD are least preferred for a Laptop on-board a Robot. The stupid ROM drive spins all the time!!

[ash]

Hey all! Good to see the discussions rolling.

Batteries:

Locomotive Module
Yep, SLA's are quite heavy, but a weight of 2- 2.5kg is acceptable for now. SLA are pretty standard for heavy robots I believe the locomotive module will be the heaviest one anyway, considering the multiple motors and chassis.. so relatively, the batteries are light.
- Its cheap
- High capacity
- Easy to recycle
- Easy to recharge (and can be recharged many times). Maybe can make use of solar cells?
- Reliable with tough and sturdy construction

For some numbers, we can get an 12V SLA with a capacity of 7000mAH for around 1.8 Kg. We probably need 12V for the good quality motors we'll use.

What we need to figure out is the total current draw of the motors.. which depends on the load (ie total mass of the robot and surface inclination).

System Module
For this one, I recommend using Lithium Polymer or NiMH. LiPo is very desirable for ALL purposes (including motor), but they are super expensive and quite hard to recharge. Both are lighter than SLA, but do not enjoy the tough construction.. so are quite fragile if not handled properly.

The system board module will need to be light because it'll be used in multiple situations (ie with other types of locomotive modules), so SLA's are ruled out.

Before we proceed, we need to know the total power budget of the system board. xhx, can you provide us with all the possible power specs of the laptop?

I think the most important battery factor would be capacity. We can use boost and buck regulators to give whatever voltage level we desire, but we still face the limited total current capacity issue.

Laptop weight issues
We are planning to rid of the LCD monitor anyway and use the VGA connector whenever we need to debug. Also, the HDD will be replaced by a flash disk via a IDE adaptor. We might still need the CD-ROM to boot the software though, unless we place the OS directly on the flash disk.

The WiFi will be the biggest power consumer. That one we cannot do much about for now. Since we only got 2 USB ports, we'll use the PCMIA port for the 802.11g module.

[KINETIC_JOULES]

Wow. . . nice! I'll be contriuting more now, i just got a new scanner/printer! I can draw out a design, scan it, and put it on here for you guys! I've just got to go start on the design soon. I don't have to ho back to school 'till Thursday 'cuz of the hurricane, so I'm good!

[raj87verma88]

A lot has happened in the past few weeks and I have missed all the action. Will need to read a lot to catch up with you guys.