Thursday, October 2, 2008

Open Source Digital Servos

The open source hardware and software designs available from OpenServo look to be a viable alternative to the expensive digital servos used in building a Robo One class robot. The OpenServo replaces the analog control board in a low cost analog servo with a digital controller based off of the Atmel AVR. This digital control board allows for better control and feedback from the servo.

In other news it looks like Microchip is trying to buy Atmel. Which probably wouldn't change much of anything, but it is still strange.

Wednesday, October 1, 2008

High-Precision Tri-Axis Inertial Sensor

ADIS16365: High-Precision Tri-Axis Inertial Sensor

For those of you in the robotics community interested in the progress in the micro-electro-mechanical systems (MEMS) world, Analog Devices has managed to fit 3 accelerometers and 3 gyros into one package, and they have started sampling the latest version. This is a significant improvement to the design and development of many autonomous robots. About the only thing keeping it from being perfect, for my application, is that it is missing a magnetometer and maybe an altimeter. They did however provide an auxiliary 12bit ADC that could be used for those sensors.

This inertial sensor provides analog to digital conversion at 14 bit resolution via SPI Bus at up to 819.2 Samples per second. Keep in mind that this is preliminary information and subject to change and many of the specific parameters are still to be determined.

There are two critical advantages to this sensor; the first is the small size of the sensor which is 23mm on a side and that it connects via a flex connector so you do not have to deal with trying to solder BGAs, secondly by integrating the MEMS devices in the same clean room facility and possibly on the same silicon wafer they should be able to reduce the angular misalignment and non-orthogonality between the axes.

Even better though is that an older model is already available with similar specifications. However according to our contact at Analog Devices, the new sensor has several significant improvements. The new sensor improves the bias stability of the gyros by more then 50% and increases the maximum saturation of the accelerometers to 18g, up from earlier 1.7g and 10g versions. Faster data transfer rates using SPI burst mode and external sync options are also available.

ADIS16365: High-Precision Tri-Axis Inertial Sensor

ADIS16354: High Precision Tri-Axis Inertial Sensor
ADIS16354AMLZ $325.86

Aerial Robotics

Draganfly Innovation's new six rotor co-axial Draganflyer X6 helicopter is now available for only $14,995.00 USD.

Rotomotion UAV Helicopter


After you buy or build your own it's time to check out the rules for the International Aerial Robotics Competition's 5th Mission.

Also, it looks like the JAUS protocol will become the standard for UAVs and ground robot communications, with both the IARC and the International Ground Vehicle Competition being used as undergraduate testing grounds where the real world problems can be worked out before JAUS support is mandated for military contracts.