The Use of a Hydraulic DC-DC Converter in the Actuation of a Robotic Leg
Sprache des Titels:
Englisch
Original Buchtitel:
Proc. of the 2013 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2013), Tokyo, Japan
Original Kurzfassung:
This paper presents the application of a hydraulic
DC-DC converter, namely a step down Buck Converter to the
actuation of a robot leg that is part of the quadruped robot HyQ.
The use of a Hydraulic Buck Converter (HBC) offers
significant advantages in terms of improved efficiency of
hydraulic actuation systems analogously to an electric switching
DC-DC converter as opposed to a rheostatic-type system. In this
paper, a HBC consisting of two digital valves and two check
valves is introduced to improve the efficiency performance of a
singl leg of a hydraulic quadruped robot (HyQ). This type of
hydraulic buck converter is able to support the locomotion in
two directions. The HBC operates at a switching frequency of
100 Hz in pulse-width-modulation. The better energy
performance compared to proportional control is achieved by
the use of fast check valves. The performance of the system with
a 3-way-4-position proportional valve is compared with the HBC
drive. A test rig is set up to investigate the performance of HBC
with two different controllers and a Hydraulic Proportional
Drive (HPD) system, based on proportional valves which control
flow, by throttling it, in a dissipative manner. The performance
of position tracking and energy consumption is evaluated. The
experimental results indicate that HBC systems are able to
achieve similar position tracking with relatively less consumed
energy.