Bio-inspired design of electrically-driven bounding quadrupeds via parametric analysis

This paper attempts to set the basis for a systematic approach in designing quadruped robots employing a dynamically stable quadruped running in the sagittal plane with a bounding gait, which is a simple model commonly used to analyze the basic qualitative properties of quadruped gaits that use the legs in pair. The outcome of the proposed methodology is the optimal shape of the bounding quadruped robot, i.e., the relation between its physical parameters, and the optimal size of the bounding quadruped robot, i.e., the physical magnitude of it, according to desired performance criteria. The performance criterion introduced is based on: (a) the actuator effort to sustain an active gait, very close to a passive one, and (b) the maximum payload capability of the robot for a target overall mass. The parametric study examines the behavior of the performance criterion over a range of non-dimensional variables connected to robot physical parameters and gait characteristics. The study takes into consideration data from experimental biology and ground surface properties, while it is subject to the existing technological limitations and economic restraints, i.e., the fact that there is a limited number of motor/gearbox combinations available from a practical point of view. The findings from simulation results indicate that the proposed methodology can assist in the design of new, and modifications of existing quadruped robots.