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Image Serval


Serval, the last in a line of robot iterations, is meant to serve as a quadruped for agile movement. We use the previously researched mechanisms, control structures and gained knowledge in the electronics development to build a combined and hopefully higher performing robot. Serval consists of and active 3-DOF spine (combining advantages from Lynx and Cheetah-Cub-S), leg units with adduction/abduction mechanism and a scaled ASLP-version of Cheetah-Cub-AL. All motors (Dynamixel MX64R and MX28R) are combined with in-series elastics to protectthe rather sensitive gear-boxes from harm in different load scenarios. The robot is equipped only with a minimal sensor set, consisting of a low-cost, medium-grade IMU. Collaborations, started close to the end of this thesis will provide contact and GRF sensing with capacitive sensors as well as a sensitive skin for physical guidance. Control is realized through inverse kinematics for the legs, (for now) offsets in the spine and an underlying CPG-network for pattern generation. Reflexes, like in Oncilla, were not yet implemented, but are ongoing and future work.

Key features:
  • IMU, (sensitive skin, GRF-sensors (in implementaion))
  • Inverse kinematics control with in-series elastics
  • Standard Servo-motors
  • On-board power supply
  • Possibility of up to 300g (distributed) payload
Possible applications:
  • Researching loss of limb strategies
  • Researching different feet or legs designs
  • Exploring different neural networks inspired by animals
  • Platform for sensor carrier, such as camera
  • Animal gait exploration, versatility
  • Exploring in narrow spaces

Access information

Corresponding infrastructureÉcole Polytechnique Fédérale de Lausanne
BioRobotics Lab
LocationRoute Cantonale, 1015 Lausanne, Switzerland
Unit of accessWorking day

Technical specifications

RC servo motor:Dynamixel MX64R /MX28R
lhip, standing height:0.228m
Mactuators+electr, sum:2.167
Mrobot:3.56 kg
Active degrees of freedom:15
Gait type:Various, main trot
Body lengths per second:2.11
Froude number FR (v^2/G/lhip):0.27
Maximum speed, vmax:0.8 m/s
Control board:Odroid XU4
Power supply, tethered, battery:12V (3S Lipo)

Additional information

Publication under Review, website after that

Videos: https://go.epfl.ch/ExperimentsServal

3DPDF: https://go.epfl.ch/3DPDFServal