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| Archives of past meetingsWCRS Meetings and MinutesFebruary 13, 2002Agenda followed by minutes Agenda:February 13, 2002 AgendaTime: Feb 13 (Weds) 7PM - 9PMPlace: MD203 / MD213 HEART BuildingMeeting Objective:It's BRAIN's night tonight... Mark Hillier ( HVW TECH ) will fill us in on the various types of programmable micro's you might use in your next Renaissance Robot For the beginners...
For Intermediate / advanced robot designers...
For discussion...
Agenda
MinutesFebruary 13, 2002 Meeting officially opened 7:10 PM 1.Review of previous meetings minutes... old biz?
2.Results of our Junkyard Robot visit at WTP Theatre: Quentin spoke about one of the events of the past month. He spoke about taking apart some old photocopiers at a “Junkyard Wars” event. Photos will be available on the web. It was lots of fun. Participants were able to design a walking robot (with the aid of duct tape), and all usable spare parts were retained by Craig. The creation needed additional welding work and a controller. It was a basic 2 motor walking robot. It was a fun night, and if done again, a motor control, remote control and other DC motors would be useful to have at hand. There are few DC motors in a photocopier. It was fun, and this event may be repeated based on donations of devises to take apart.
3.Science Center wants to join WCRG event (Tech Heads) There are nice opportunities with the Calgary Science Center where the WCRS may be able to make a strong presence by participating in events and setting up displays. Something the WCRS should be working toward.
4.AIBO's visit in SAIT newspaper. There was a write-up in the SAIT newsletter (the Weal) about the AIBO visit. 5.SAIT Students developing promotional CD for WCRS: New Media Technologies are a group of students at SAIT that are working on a promotional CD for the WCRS. Will include information, videos, games, etc, that may be sent around to schools and other organizations. Craig demonstrated some of the past work by these students, including an interactive java menu system that is very attractive. Will help with promoting the society. The video games will be classic based games, done in Macromedia Shockware. 6.Central Alberta Science Network along with the BP Science
Festival Committee are gearing up for another exciting Science Festival (May 24
&25): We are hoping that volunteers from the WCRGames and the WCRS would be willing to participate in the Science Showcase held at the Science Festival Grounds (Downtown Red Deer). The festival is open to the public. 7 WCRG Events for this year: There have been many on-line discussions about the current contests for the WCRGames. Atomic Hockey will be eliminated after this year. Other changes are to happen to other competitions; as an example, the sumo wrestling rules are about to change to the smaller Japanese standard (from 9” to 8” squared, and from 5kg to 3kg) 8.Sponsorship from Gov. looks good The government hopefully will continue to sponsor the activities of the WCRG. Science and Innovation is going through a name change to Alberta Innovation. We are looking forward to more financial support from them. 9.Potential New Events: 10.TransAlta's robot “roadkill” project An organization in Alberta is setting up a driver-training course and is looking for someone to design robotic creatures to help train drivers (the robots will be mock animals that will appear quickly on the road and will be used to test driver reaction). This is a job opportunity to whoever is interested. (Author’s note: depending on driver reaction, this may be an ongoing maintenance contract!) 11.Announcements? Births? Deaths? Quentin has some NiCad batteries available that have been salvaged. The charges are gone but the batteries are good. Available to whoever wants them, provided they’ll be used. A member announced that there are about 6 computers and a dozen hard drives to whoever wants them. Another member has some hard drives available and 10BT NIC cards to whoever wants them. A comment is that some of the older computers do not require CPU fans and so may be easier to deal with in a robotic setting. There is enough processing power to make use of the abundant “utility” software available on the web. The standard communication ports found on these computers may also be of use.. Craig presented some of the SAIT Computer Engineering Students projects, including robotics or sensor systems. Web Site: http://learnat.sait.ab.ca/ict/proj379/project2.htm 12.New Business? The Yahoo emailing has at times been overwhelming. Suggestion is to redirect these emails to a folder. Users may also create a digest in Yahoo to help with the busy discussion group. Nancy is membership coordinator. Full membership is $5. See the “How to Join” section of the WCRS site. 13.Next Meeting Date? Suggestion to establish the meeting dates for the entire year, alternating between Wednesdays and Thursdays. ( Author’s Suggested dates:
A Build night is suggested next month where members can start creating robot(s) together as a team effort. Details will be determined once an appropriate lab is booked at SAIT (Craig to announce at a later date). 14.Meeting Body Marc’s presentation (HW Tech): A robot is a normally autonomous that acts under its own thoughts or brains. There are advantages to a hard-wired brain, but changes are not easy. A microprocessor or micro controller is better because the program can be changed to suit the environment. Some of the basic elements of a basic robot:
Many motors will function in the hundreds of milliamps or 2-3 amps. Relays, H-Bridge, transistors, SCRs, SSRs, You need a way to vary the voltage to control speed. Pulse Width Modulation (PWM) is one means of controlling the motor speed. PWM is one way to control motor speed by switching the motor on and off at various duty cycles (varying the on time versus the off time). Pulse Code Modulation (Pulse Position Modulation) is providing a series of pulses at variable frequencies based on the input (normally the higher the voltage the greater the output frequency). Stepper motors are found in printers, photocopiers, etc. This type of motor contains many coils allowing for a high degree of precise motion. Stepper motors are normally not high torque and not recommended for robots as they may be difficult to control. Costs are also higher. Touch sensors are the easiest to deal with. Essentially, they are just switches that are either open or closed, on or off. Other sensors, like distance, will provide a varying degree of voltage. You will need to convert the analog value to a digital value (AD converter). Some light sensors (for instance, CDS) may need a device to measure resistance. TTL (Transistor-Transistor-Logic) and other micro controller systems cannot handle much current. They may be capable of handling one LED. There are several different devices that are used to convert the low current from TTL to high current to drive a motor. The problem with relays is that they provide high output surge voltages that may destroy the semiconductor logic. There are other options available that may be discussed at a later time. Communications: It’s relatively easy to come up with an encoding system. There are standards out there. Costs primarily has to do with what you’re willing to learn by making due with what you have and how deep your pockets are. Some programmable elements (controllers) include: Basic Stamp
Oopic (OO is Object Oriented). C++ or Basic to program. The Oopic 2 is self-contained (except for cable). Sell for about $80. Starter kit about $100.00. You will need oscillators and other accessories for connection to the computer or programmer. Assembly language is required for PICS, making it more difficult to follow the code, although compilers may be used. PIC programmers and compilers are required for PICS. The basic programming steps for all the devices are all essentially the same. The 68HC11 uses assembly language. Heavily used on more advanced robots. If you’re getting started, Marc recommends starting with Basic stamps. They’re easy to use. Remember, you can move the modules from project to project and they are re-programmable if you’d selected that type of re-write able device. A micro-controller contains all its required elements within, whereas a typical CPU relies on external devices for control. Be realistic and simple in your approach to building your robot. Maintain simple objective and stay away from the “flash”. That can be added later. Robotics contests are a great way to establish simple, straightforward goals. Think of how you want to program your device. Select whatever you’re familiar with base to designing the robot. Don’t try to learn too much at once. Use what you know as a working base. You can build up to a more complex system later. Remember, building a robot should be fun. Keep it that way. Colin has a controller to show off, and Quentin has a firefighting robot (“Flop”). There are a couple of walking robots, lots of controller cards, Lego Mindstorm and some off-the-shelf remote controlled bugs. There is even an autonomous underwater robot builder here and he can show off some pictures. There are boxes of various parts and project ideas. In the future we may pick one controller and spend the evening to program it with a basic function. The meeting ended with a show-and-tell, where participants were exchanging information about the various devices they brought with them. |