System-Level Performance Metrics Sensitivity of an Electrified Heavy-Duty Mobile Manipulator

TL;DR

This work addresses how payload impacts the system-level performance of electrified heavy-duty mobile manipulators (HDMMs) by analyzing four metrics (delivered power, actuator force, energy expenditure, and efficiency) as functions of the TCP payload $m_{TCP}$. It introduces a gear-equipped PMSM-powered EMLA model with equivalent circuits for the inverter, motor, gearbox, screw, and load, leveraging force-to-voltage and speed-to-current analogies alongside Park’s transformation to the $dq$ frame to derive $\tau_m$ and the EMLA dynamics, including energy-efficiency maps. A 3-DoF HDMM is simulated to compute the sensitivity metrics $\boldsymbol{\Psi}$ with respect to $m_{TCP}$ via finite differences (perturbation $\Delta_m$) using a second-order inverse differential kinematics framework and inverse dynamics. The results provide actionable guidance for actuator selection and battery sizing, enabling more efficient and sustainable electrified HDMM operation in robotic vehicular systems. The methodology supports informed design choices for high-performance, autonomous HDMMs mounted on mobile platforms.

Abstract

The shift to electric and hybrid powertrains in vehicular systems has propelled advancements in mobile robotics and autonomous vehicles. This paper examines the sensitivity of key performance metrics in a electrified heavy-duty mobile manipulator (HDMM) driven by electromechanical linear actuators (EMLAs) powered by permanent magnet synchronous motors (PMSMs). The study evaluates power delivery, force dynamics, energy consumption, and overall efficiency of the actuation mechanisms. By computing partial derivatives (PD) with respect to the payload mass at the tool center point (TCP), it provides insights into these factors under various loading conditions. This research aids in the appropriate choice or design of EMLAs for HDMM electrification, addressing actuation mechanism selection challenge in vehicular system with mounted manipulator and determines the necessary battery capacity requirements.

Figures (6)

• Figure 1: Illustrative configuration of an electrified HDMM
• Figure 2: EMLA structure and components
• Figure 3: Equivalent circuit of 3-phase PMSM
• Figure 4: Equivalent circuit of PMSM in dq-axis
• Figure 5: Equivalent circuit of mechanical components of EMLA