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12/03/06 |
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DEXTER-2 DEXTER-2 is an intelligent, versatile and rugged robot designed for navigation in unknown terrain. Using its powerful sensors and intelligent control system, it is capable of navigating its way autonomously.DEXTER-2's brain is a powerful Intel 3.0GHz processor with Hyper threading technology having 800MHz front side bus on a ASUS P4P800 Deluxe mother board. It is the robotic platform with powerful yet precise four wheel differential drives with active power control and trapezoidal drives. It also has an 8 Axis robotic arm. The arm works in combination of rectangular and spherical coordinate system. DEXTER-2 is also equipped with a navigation control system, position tracking system, automated obstacle avoidance and routing system, Laser range finder (Developed in Software), ultrasound scanner. Its movements can be controlled remotely and its position can be tracked and monitored continuously.
While in its automated mode, DEXTER-2 uses its intelligent obstacle avoidance system to repeatedly make maps of its surroundings and accordingly make navigation decisions so as to reach the desired destination in an efficient way. Its powerful tools make it useful as a remote unmanned work station. Robot also supports wireless LAN. Gyro-Stabilized cameras with light intensifier lens for night vision assist the remote human operator, by continuous video feedback from DEXTER-2. For exact positioning DEXTER-2 has a newly developed infrared positioning system providing off board path detection and correction which corrects positional errors made by robots servo drive motion controllers. This system is just like Global positioning system but shrunk up to lab scale. It also has tilt and inclino meters and a digital compass and micro machined two axis accelerometer and gyroscopes for precise path planning.
We developed DEXTER-2 as a prototype robotics research platform to provide an alternative to expensive commercial platforms like the Pioneer robots. Total building cost of Dexter is about $500, the most expensive part being the onboard computer. DEXTER-2 can be used in research labs and in industry for developing and testing new algorithms for navigation, image processing etc.
Videos of Dexter:
Locomotion Video: This video shows that Dexter is powered by four wiper motors (motors used in wipers of trucks and buses). Since Dexter weighs more than 250 pounds, 4 powerful motors are required for navigation. This is a differential drive system with strong suspensions to avoid jerky movements. Due to differential drive, we can get a zero degree turning radius. There is a bump switch to detect close obstacles. We made shaft-encoders by using parts from a standard computer mouse. Click Here for video: Dexter-Locomotion
Processor and Circuits: This video shows the three layers of circuits. Layer 1 forms the base level circuits which inteact with the motors. Layer 2 are the communication level circuits. and Layer 3 circuits are the microcontroller circuits which gathers the various sensor inputs and feeds to the onboard processor. Also show in the video is the on board processor: Click here for video: Processor and Circuits.
Robotic arm: This video shows the movement of the robotic arm. Click here for video: Robotic Arm
UDM: Dexter has an Ultra sonic distance meter which gathers the input of the obstacles of surrounding and the readings are used to create the map of the environment in front of Dexter. Click here for video: UDM
Infra-Red Positioning System (IPS): This system helps to localize the robot in a closed environment w.r.t to a fixed position that is the tower holding the IPS system. The IPS gives the flat cylindrical coordinates of the robot w.r.t to itself. Click here for video: IPS
A power point presentation of Dexter is available here: Dexter Presentation
The pictures below show the Side-view and Front-view of Dexter.
This picture shows the circuits and Rear-view of the robot.
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This site was last updated 12/03/06
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