Robodimm: A Physics-Grounded Framework for Automated Actuator Sizing in Scalable Modular Robots
Authors: J. L. Torres, M. Munoz, J. D. Alvarez, J. L. Blanco, A. Gimenez
Organizations: CIESOL-ceiA3, Department of Engineering, University of Almería, Spain · CIESOL-ceiA3, Department of Computer Science, University of Almería, Spain
Selecting an appropriate motor-gearbox combination is a critical design task in robotics because it directly affects cost, mass, and dynamic performance. This process is especially challenging in modular robots with closed kinematic chains, where joint torques are coupled and actuator inertia propagates through the mechanism. We present Robodimm, a software framework for automated actuator sizing in scalable robot architectures. By leveraging Pinocchio for dynamics and Pink for inverse kinematics, Robodimm uses a Karush-Kuhn-Tucker (KKT) formulation for constrained inverse dynamics. The platform supports parametric scaling, interactive trajectory programming through jog modes, and a two-round validation workflow that addresses actuator self-weight effects.
Figures & tables
Figure 1: Unified Robodimm architecture with DEMO and PRO execution paths.
Figure 2: Robodimm graphical interface. The layout integrates 3D visualization, jog/program tools, robot configuration, and dynamic analysis outputs in a single workspace.
Joint
Correlation
RMSE [Nm]
Bias [Nm]
J1
1.0000
0.026
-0.000
J2
0.9994
2.773
-0.920
J3
0.9996
1.545
-0.036
J4
0.9961
0.089
-0.000
Table 1: Metrics reported for DEMO/PRO torque comparison in the palletizing cycle (scale 1.6, payload 10 kg).
Figure 3: CR4 palletizing case study for the final benchmark scenario (scale 1.6, payload 10 kg). Top row: actuated joint positions, velocities, and accelerations. Bottom row: DEMO/PRO torque comparison, absolute torque error, and RMS torque by joint. In the torque panel, J1–J3 use the left axis and J4 uses the right axis.