|Surveyor Robotics Journal|
Tue, 28 Mar 2006
new Java console adds scheduled archiving and Internet access control for SRV-1 robots
There's a new update for the Java base station console on http://www.surveyor.com/srvdownload/. We've added full WebcamSat v3.1 functionality, which in particular includes scheduled archiving and user access control, so it's now possible to capture the live feeds from the SRV-1 robots as well as manage access to the robot by Internet users.
Here's a short sample that was just captured - it's a 268kb AVI file - click here to view. The archiver captures to AVI format, and the files can be easily converted to other formats, including Quicktime. Here's a Quicktime version of the same clip -
click here to view
A more complete description of the WebcamSat functionality that's now part of the SRV-1 console can be found here - WebcamSat description.
Tue, 21 Mar 2006
software work-in-progress report ...
We've posted one minor update to the firmware that relates to the object tracking code - the previous version wasn't properly displaying the tracked objects in the lowest resolution mode, so that's been fixed. Also, the performance of object tracking algorithm has improved in its handling of a wider range of colors.
We have a couple of interesting projects in the works. One is the addition of support for the infrared emitters and detectors that are found on the new SRV-1 controllers. We're adding 3 functions, seen in the last row of the Java console -
The left-most pair of buttons turn on/off a beacon function, which would enable a robot can act as a beacon for other robots. The right-most pair of button control a beacon tracking function, which puts a robot in the mode of searching for a beacon, and if located, travel to it. The middle buttons enable/disable a proximity detection override when driving. The order of the buttons will probably change, and the colors definitely will change when our paint program actually figures out how to save the right colors.
Finally, we've set up a project on SourceForge for the SRV-1 code, and hope to start posting code there in the next week or so. If interested, you might bookmark the page and check back from time to time.
Sat, 18 Mar 2006
pricing set for SRV-1 controller-only starter kit
An SRV-1 controller-only starter kit for users planning to interface to their own robotic base has been set at $295. The kit includes an SRV-1 controller with camera and an SRV-1 base station radio, plus all required software, but the kit does not not include the battery pack, battery charger, or motorized robot base that are found in the complete SRV-1 starter kit. The SRV-1 controller-only starter kit components are shown here
The SRV-1 controller is designed to interface to two DC gearmotors drawing up to 650 milliamps each in continuous operation, or 1000 milliamps peak per motor. The motor power is drawn directly from the battery supply, and the supply can be in the range of 6.0VDC - 9.0VDC. The SRV-1 controller uses pulse width modulation to control the motor speed, and has an onboard low drop-out ("LDO") voltage regulator to supply the onboard control electronics, so only a single power source is used for motors and electronics.
Beyond control of the SRV-1 robot base, the SRV-1 controller interface has been tested and worked well with a 1/24 scale Hen Long radio controlled tank and a Tamiya tracked vehicle kit.
The SRV-1 controller-only starter kit can be order online.
Thu, 16 Mar 2006
interfacing SRV-1 controller to Tamiya tracked vehicle chassis kit
The folks at Little Scientist in Toronto (www.littlescientist.net) use a lot of Tamiya robotics kits in their classes, and they asked if we could interface the SRV-1 controller to the Tamiya tracked base.
This particular kit had a plastic chassis with lots of mounting holes, so it was very easy to work with - maybe that's how they do things in Canada, as the US version has a wood base. Also, the standard Tamiya kit comes with a single gearmotor, and Little Scientist substituted the Tamiya twin-motor gearbox.
It was very easy to put it all together, just soldering the 4 motor leads to the JP1 contacts on the SRV-1 controller, raising the controller up on 2" aluminum spacers to leave room for the 7.2V battery pack, and adding a power switch on the bottom of the frame. The camera still needs a mount, but we think we've found a solution (vertical pcb card slots), and are waiting for samples.
It actually all works quite well. Here's a short Quicktime movie showing the SRV-1 controlled Tamiya tracked vehicle in action.
Quicktime Movie of SRV-1 + Tamiya - 693kbytes
Fri, 10 Mar 2006
background story about SRV-1 on www.robots-dreams.com
One of the first SRV-1 test sites is located in Japan, and the tester, Lem Fugit, is the publisher of a very popular robotics web log called "Robots Dreams". Lem has a wealth of background experience and knowledge about the history and technology of robotics, as well as a passion for the subject, and he's provided a lot of helpful feedback and guidance on the SRV-1 program.
Shortly after receiving the SRV-1 for testing, Lem sent us some photos of the robot following (chasing) his dog around the house. As it turns out, that was the very first test we did when we first got an SRV-1 up and running. I don't know that dog tracking is a real market, but it seems to work well as a proof-of-concept.
Yesterday, Lem published an interesting web log entry about the SRV-1 -
describing some of the background behind the creation of the SRV-1, and comments on future possibilities. We look forward to his future comments and feedback.
Tue, 07 Mar 2006
dongle version of SRV-1 base station radio
Well ... we got our fancy SMD rework station for attaching the Silicon Labs CP2102 USB to UART bridge chip on the SRV-1 base station radio board, and it really didn't work all that well, so we tried another method shown on the Spark Fun Electronics website. Hard to believe, but this worked really well. These guys are actually surface-mounting the same Silicon Labs chip in this tutorial. In case you're wondering, here's their version of a production solder reflow station -
I didn't take photos of our skillet, but it's nicer, as it doesn't have any sides that reach up and cause burns, though it didn't cost any more than their version. Here's the SRV-1 radio board with the CP2102 attached.
We're still testing this new design - we've already found one change to the circuit board, so initial robot shipments will go with the original radio shown with the other SRV-1 photos until this design is solid.
By the way, I should mention that there are 2 versions of these Zigbee radio modules - the one we're using has maximum RF power output of approximately 70 milliwatts, and pretty good range. The other version only outputs 1 milliwatt, so the range is maybe 70% less, but the cost drops by about 40%. We will eventually add an option for the lower cost version of the radio for users who don't need such a wide range and want to save some money.
Mon, 06 Mar 2006
new version of SRV-1 firmware and java console is available for testing
We've posted new versions of srv1.hex (SRV-1 firmware) and srv_java.zip (SRV-1 java base station console) for testing. You can find these links at http://www.surveyor.com/srvdownload/
Several reasons for the update:
Sun, 05 Mar 2006
some production notes on the SRV-1 robot and base station radio
Here's one of the production units that will ship out at the end of the week.
There are still a few loose ends to wrap up - one is the battery pack mounting, and the other is the camera mounting. For the battery pack, we're trying some velcro "dots", which will allow us to separate the pack from the robot for shipping. With the camera, we've avoided any permanent mounting, as we are looking at the eventual possibility of a dome or some kind of cosmetic cover to which the camera would mount. For now, the camera will be attached to the frame with a removable clip, and tethered to the controller board with a 2" cable.
The only other bit of unfinished business is assembly of the new base station radio boards. It may not be obvious from the photo, but this will actually be a USB dongle - we're just waiting for the USB connectors, which are due in the next day or so. The dongle version of the radio is a lot less expensive to produce, and it uses a nice Silicon Labs CP2102 USB-to-UART bridge chip, which has better driver support than the first radios we used.
Thu, 02 Mar 2006
first SRV-1 shipments start March 10; taking order reservations now
The new SRV-1 controller board is functioning well, so we will begin shipment of robots on March 10. Online orders can be placed starting next week through this link, but in the interim, if you wish to order, please contact us by email to reserve a place in line.
Wed, 01 Mar 2006
understanding the SRV-1 sensors
The current SRV-1 controller includes 2 primary sensors - the digital camera module, and an array of 4 infrared emitter/detector pairs. The digital camera was always a key portion of the design, both for internet-based telepresence as well as for image processing on the robot itself for object detection, object tracking, and autonomous navigation.
Beyond on-board image processing, we wanted to add some low-cost sensors to help the robot in deriving its orientation and position, and we experimented with a variety, including a digital compass and several ultrasonic ranging modules. We eventually abandoned these, as the compass was subject to many magnetic field disturbances when operating indoors (not the least of which were the robot motors), and the ultrasonic ranging was of limited value without a frame of reference for orientation. Also, the ultrasound modules were highly prone to false triggers when the robot was moving, and the ability to actually resolve specific objects was quite limited.
We decided to take a different path, focusing instead on developing firmware that would help the robot navigate primarily by visual cues, much the way a human navigates, but provide the possibility of an external reference frame using easily deployed infrared beacons. In the process of testing this concept, we realized that there would be several benefits from the addition of the infrared components, as one SRV-1 robot could itself act as a beacon, which would be useful for coordinating the movement of multiple other robots. Also, the SRV-1's could use infrared to communicate with each other at close range (albeit low data rate - 1000 baud at best), and the infrared components could operate as proximity sensors for collision avoidance. Though software still has to be developed to take full advantage of these possibilities, the addition of about $5 worth of components offers the potential for significant functionality.
Beyond this, we have provided connections from the ARM7 processor board for other external sensors, but for now, our main software development focus will be on taking maximum advantage of the vision and infrared sensors provided on this version of the SRV-1 controller.