Design and Modeling of a Lightweight and Low Power Consumption Full-Scale Biped Robot

Abstract

This paper introduces the design methodology, the modeling and the power consumption tests for a newly developed biped robot equipped with 12 DOFs. The robot is 1.1 meters tall (lower limbs) which makes it comparable in dimension with other state-of-the-art full-scale humanoids. By using a combination of 3D printing techniques and lightweight materials, the system weighs only 10.8[Formula: see text]kg (without batteries) while retaining high links strength and rigidity. Without compromising the workspace dimension, the robot presents a very low weight-to-height ratio (9.8[Formula: see text]kg/m) that translates into a safer operation and reduced energy consumption. To perform elementary locomotion primitives, e.g., changing the support from one foot to the other or lifting its body, the robot prototype consumes only 65 watts. Simulation results demonstrate the suitability of the robot’s kinematics to perform walking motion and predict an average power consumption of 200 watts. The direct kinematics of the robot is presented together with its inverse dynamics based on a Chaotic Recurrent Neural Network (CRNN). The adaptive model is identified using a recursive least squares algorithm that allows the CRNN to predict the torques at different step lengths with a MSE of 0.0057 on normalized data.

Parametric Design and Prototyping of a Low-Power Planar Biped Robot

“…A comparison study for different humanoid robots is given in [ 11 ], where the power/weight ratio of known humanoid robots varies between 25 W/kg and 133 W/kg. Hence, the proposed biped robot design can be considered low power.…”

“…The LOLA [ 10 ] project is an instance of lightweight design, in which issues like fast, human-like walking are also targeted. Another study with a focus on lightweight design and low power consumption biped using 3D printed parts is presented in [ 11 ]. Topology optimization is another important approach that is being utilized in the structural design of robotic legs [ 12 ] and in hybrid legged-wheeled robots [ 13 ].…”

“…The total rated power consumption of the robot joints is 600 W, which leads to a low power-to-weight ratio of 30 W/kg. For a comparison of the power-to-weight ratio for various humanoid robots, readers may refer to [ 11 ].…”

NU-Biped-4.5: A Lightweight and Low-Prototyping-Cost Full-Size Bipedal Robot

“…NU-Biped-4.5 is a bipedal robot developed at Nazarbayev University's Humanoid Robotics Laboratory. It represents the evolution of previously designed bipedal robots, specifically NU-Biped-3 [43] (see Figure 1S) and LARP [47] (developed at Politecnico di Milano), which also featured a lightweight structure and comparable dimensions. For the new robot, improved link rigidity, slimmer form factor, a high power-to-weight ratio, low energy consumption, and low prototyping costs were considered as main design objectives.…”

“…Given that most of the robots considered in this study are full-scale, with a height comparable to that of an adult human, a weight-to-height ratio [42,43] can be introduced to demonstrate how efficient the design is in terms of reachable workspace. Longer links with low mass enable the robot to reach farther and perform tasks in diverse environments while maintaining stability and reducing the risk of toppling over.…”