Energy-Based Injury Protection Database: Including Shearing Contact Thresholds for Hand and Finger Using Porcine Surrogates

TL;DR

This study reevaluates all prior porcine surrogate data and establishes energy thresholds across geometries and contact types, forming the first energy-based Injury Protection Database, which enables the development of meaningful energy-limiting controllers that ensure safety across a wide range of realistic collision events.

Abstract

While robotics research continues to propose strategies for collision avoidance in human-robot interaction, the reality of constrained environments and future humanoid systems makes contact inevitable. To mitigate injury risks, energy-constraining control approaches are commonly used, often relying on safety thresholds derived from blunt impact data in EN ISO 10218-2:2025. However, this dataset does not extend to edged or pointed collisions. Without scalable, clinically grounded datasets covering diverse contact scenarios, safety validation remains limited. Previous studies have laid the groundwork by assessing surrogate-based velocity and mass limits across various geometries, focusing on perpendicular impacts. This study expands those datasets by including shearing contact scenarios in unconstrained collisions, revealing that collision angle significantly affects injury outcomes. Notably, unconstrained shearing contacts result in fewer injuries than perpendicular ones. By reevaluating all prior porcine surrogate data, we establish energy thresholds across geometries and contact types, forming the first energy-based Injury Protection Database. This enables the development of meaningful energy-limiting controllers that ensure safety across a wide range of realistic collision events.

Figures (11)

• Figure 1: Shearing collisions, common in real-world contact scenarios, are not yet covered by existing energy-based safety thresholds. To investigate injury severity, the robot is modeled as a moving mass with defined impact geometry and collision angle. Surrogate experiments provide initial energy limits based on contact geometry, enabling estimation of safe energy densities for non-perpendicular impacts and adding it to the Injury Protection Database.
• Figure 2: Schematic of the shearing contact and energy distribution as well as skin deformation. The individual layers of tissue can be seen here qualitatively specifically on the back of the hand. The muscle tissue can be disregarded.
• Figure 3: Experimental setup for unconstrained shearing collision injury analysis.
• Figure 4: Impact conditions: a) dissected specimen with collision locations and b) impact angle $\alpha$ for different impactors.
• Figure 5: Observed injury types.