Experimental Demonstration of High-Performance Robotic Balancing

Autonomous Real Time Architecture for High Performance Mobile Robots

“…The presented system is used on a 5-DoF balancing machine called Tippy, and experimental results are presented in Driessen et. al [4]. Tippy uses the balancing algorithm of Featherstone [16] to balance and track a command signal in 2 D. The robot is a full 3 D balancing machine, but in [4] it is configured as a 2 DoF planar reaction wheel pendulum (RWP).…”

“…(Currently only logging is performed and the CPU is IDLE for most of the time.) The results presented in [4] use precomputed trajectories.…”

“…In this way lengthy control signals can be stored in a compact way in the microcontroller's limited memory. In the experiments presented in [4] a command signal of 10 seconds (for 1 KHz 10,000 points are required) has been compressed to only 162 points (61.2 compression ratio), which are then used to reconstruct the original signal in real-time.…”

“…For the robot presented in [4], state estimation consists of position and velocity estimation from joint encoders. For joint angle positions we use two iC-Haus' iC-MU150 18-bit [21] magnetic absolute encoders, and for the motor position we use Maxon's ENX 16 12-bit incremental encoder [22].…”

“…At the time this paper is written, the overall cost of the presented unit is less than 50 euros, and the framework implements a complete control system, which includes wireless communication between a user and the robot, highbandwidth logging, high frequency sensor-sampling, state estimation, control loops, on-board real-time dynamics computations, and fault detection. The effectiveness of the system is demonstrated on a custom-built balancing machine named Tippy [4] (see Fig. 1), in the task of balancing and command tracking, an ability that inherently requires fast responses.…”