Meta 

  

 

Meta is our first robot with electric actuation. We are using Maxon DC motors to actuate the hips and ankles with series elastic actuation. The passive knees are equipped with a solenoid-driven latch which unlocks the knee at the start of the swing phase.

 

In addition to adding electric actuation, we have considerably enhanced the electronic subsystem. A PC104 computer on-board runs XPC-Target, a real-time operating system that can run controllers that we build in Matlab Simulink. The robot has encoders on each joint and on each motor. It also incorporates an inertial sensor that measures the absolute orientation of the robot with respect to gravity. We run a 1kHz control loop which enables both force and position control on all actuated joints. We are currently testing various control strategies with the purpose to stay close to the passive motion, while maximizing the stability of the gait.

 

The mechanical design of Meta is partly a copy of our previous machine Max. In addition to this design, Meta has actuated ankles and an actuated upper body instead of a bisecting mechanism. META is 1.1 m tall and weighs 12 kg. 

 

Meta is able to take 3 cm stepdowns in the floor and walks stably at a speed range of 0.3-0.65 m/s. It can start from a standstill and get to a full stop after walking.

 

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