VRA: Grounding Discrete-Time Joint Acceleration in Voltage-Constrained Actuation

TL;DR

This paper introduces Voltage-Realizable Acceleration (VRA), a new joint acceleration interface that ensures commanded accelerations are physically realizable under voltage constraints, improving control accuracy.

Contribution

VRA provides a novel abstraction that grounds kinematic accelerations in voltage-constrained physics, addressing unrealizable commands in electric actuators.

Findings

VRA removes unrealizable accelerations in experiments.

VRA restores near-constraint execution.

VRA reduces oscillations caused by constraints.

Abstract

Discrete-time joint acceleration constraints are widely used to enforce position and velocity limits. However, under voltage-constrained electric actuators, kinematically admissible accelerations may be physically unrealizable, exposing a missing execution-level abstraction. We propose Voltage-Realizable Acceleration (VRA), a joint-level acceleration interface that grounds kinematic acceleration in voltage-constrained actuator physics by restricting commanded accelerations to voltage-realizable constraints. Hardware experiments on electric actuators and a wheel-legged quadruped show that VRA removes unrealizable accelerations, restores consistent near-constraint execution, and reduces constraint-induced oscillations.