BigDog : Advanced Robotics

With a sense of balance seemingly flawless and a quasi natural, BigDog robot is probably the most compelling and fully autonomous robot ever made.

Hardware Scheme of the BigDog robot

Developed by Boston Dynamics under a program funded by DARPA (Defense Advanced Research Projects Agency), BigDog has been primarily designed to test the possibilities of natural locomotion through various more or less rugged terrain and under various degrees of tilt .

With 1 meter long and 75 centimeters tall and weighing 110 kg, the robot is supported by four servomotors equipped with jointed legs and 50 sensors found in other parts of the body whose duties extend from the control of the load carried (up to 170 kg!) recognition of the surrounding terrain. Its speed reached 6.5 km per hour and it readily crosses slopes of 35° inclination, positive as negative.

Scheme of the software logic

Its movement is controlled by an onboard computer that receives information from multiple sensors of the craft. Navigation and balance are also managed by this computer.

Big Dog is powered by a one cylinder two-stroke 15cv engine, similar to a kart, which spuns at 9000 rpm. The engine drives a hydraulic pump which itself led actuators legs. Each leg has four actuators (two for the articulation of the "hip", one for the "knee" and the "ankle") for a total of 16. Each actuator includes a hydraulic cylinder, a servo-hydraulic valve, a position sensor and a force transducer. The electronic board is fairly modest. A rugged PC/104 card with a processor of Pentium 4 class running QNX. BigDog is also equipped with laser gyroscope and a stereo vision system.

BigDog demonstrates its ability to avoid falling under the effect of external disturbance or imbalance on slippery ground. His behavior under any circumstances is remarkably natural :

Source : http://www.bostondynamics.com

3D vision : how the BigDog locates himself in space

Less than half the Earth's landmass is accessible to existing wheeled and tracked vehicles. But people and animals using their legs can go almost anywhere. The mission given to Boston Dynamics is to develop a new breed of rough-terrain robots that capture the mobility, autonomy and speed of living creatures. 

Such robots will travel in outdoor terrain that is too steep, rutted, rocky, wet, muddy, and snowy for conventional vehicles. They will travel in cities and in our homes, doing chores and providing care, where steps, stairways and household clutter limit the utility of wheeled vehicles. Robots meeting these goals will have terrain sensors, sophisticated computing and power systems, advanced actuators and dynamic controls.