Loki

Loki

“Loki” is named after the Norse god of Mischief.  Since with Robotics, “anything that can go wrong, will go wrong… and usually break something important”, Loki seemed like an appropriate name.

Loki builds upon the software of Seeker and Mr. Roboto, including remote control and diagnostics over WiFi, but adds more capable vision processing, speech recognition, indoor pathfinding (Using A*), basic Artificial Intelligence, and general refinement of the architecture.  His latest addition is an arm, so he can start manipulating things in his environment.

Loki Design

The “body” of Loki is built completely from scratch, using mostly aluminum.  The unique design allows a laptop computer to double as the robot brains, and also as a display screen in Loki’s “chest”.

The Cameras are two Logitech Notebook Pro webcams, to allow me to experiment with stereo vision. (I have basic stereo vision working with OpenCV, but not happy with the depth perception yet.)

Like most of my robots, the laptop gets sensor data from a PIC processor, mounted on a Mark III controller board, via a USB to Serial converter.  The PIC is programmed using the CCS “C” compiler, and the PC software is written using Visual C++ .

The PIC I/O is expanded with several I2C chips to provide extra sensor inputs including 2 PIR motion detectors, 10 IR range detectors, 2 Ultrasonic rangers, 4 bumpers, an electronic compass, and motor speed and direction monitors for each wheel.  Head motion and arms are handled by Dynamixel AX12 servos.  The shoulder joints are custom chain-drive driven by precisely controlled motors.

Click on a link below for hardware design info, or the source code.  See the Seeker documentation for an overview of the source code to get the “big picture”.  Also, the source code .zip has latest hardware schematic info, etc:

Electronics

Software

Mechanical