Establishing Safety Standards for Humanoid Robots: Challenges and Innovations

The Rise of Humanoid Robots in Industry

Last year, a humanoid warehouse robot named Digit started handling boxes of Spanx. Digit can lift boxes weighing up to 16 kilograms and transport them between trolleys and conveyor belts, assisting human workers by taking on heavier tasks. It operates within a designated area, separated from people by physical panels or laser barriers. This safety measure exists because despite Digit's generally stable bipedal movement—characterized by a distinctive backwards knee bend—it can sometimes fall. For instance, at a trade show in March, Digit was smoothly moving boxes until it suddenly collapsed and dropped its cargo.

Physical Safety Concerns

The possibility of such malfunctions around humans is concerning. No one wants a 1.8-meter-tall, 65-kilogram machine to topple onto them or have a robot arm accidentally strike a sensitive body part. Pras Velagapudi, CTO of Agility Robotics, highlights how even a small impact to vulnerable areas like the throat could cause serious injury. Consequently, physical stability—especially the ability to avoid tipping over—is the primary safety issue identified by experts developing new standards for humanoid robots.

Need for New Standards

The IEEE Humanoid Study Group emphasizes that humanoid robots differ significantly from traditional industrial robots and mobile robots, necessitating new safety standards to protect operators, users, and the public. Their upcoming report outlines challenges including physical and psychosocial risks, privacy, and security concerns that need addressing before humanoids are integrated into collaborative workspaces.

Dynamic Stability and Safety Features

Humanoids are "dynamically stable," meaning they require active power to maintain balance by exerting forces through their limbs. Unlike traditional robots, which can be instantly powered down during an emergency, cutting power to a humanoid likely causes it to fall, escalating safety risks. To mitigate this, companies like Agility Robotics are developing features that allow robots like Digit to decelerate smoothly when a person approaches, rather than abruptly powering down. For example, the robot might gently put down its load and lower itself safely before shutting down.

Standardizing Safety Goals While Encouraging Innovation

Different robots may address stability challenges in various ways. Federico Vicentini of Boston Dynamics stresses the importance of standardizing safety goals without limiting design solutions. He leads an ISO working group focused on standards for industrial robots with active stability control. The goal is to define clear safety expectations while allowing manufacturers freedom to innovate.

Defining 'Humanoid' Robots

A major challenge is defining what constitutes a humanoid robot. Does it require legs, arms, or a head? Some experts suggest abandoning the term "humanoid" in favor of classifying robots based on capabilities, behavior, and intended use rather than appearance. The ISO standard under development refers to all industrial mobile robots with actively controlled stability, encompassing bipedal robots like Atlas, quadrupeds like Spot, and wheeled robots.

Communication and Interaction Challenges

Humanoids must effectively communicate their intentions to humans to safely share spaces. Digit uses lights to indicate status and direction, but more intuitive signals will be necessary for cooperative interactions. Audio commands may be impractical in noisy industrial settings, and multiple robots in one area could cause confusion about which one is signaling.

Psychological and Emotional Considerations

Humanoids invoke natural human tendencies to anthropomorphize, which can lead to overestimating their abilities and safety. This effect poses challenges, especially for robots designed to provide emotional support or care. The IEEE report recommends incorporating emotional safety assessments and policies to reduce psychological stress or alienation.

User Expectations and Inclusive Design

Surveys show that users expect humanoid robots to express emotions, read human micro-expressions, and use multiple communication modes like gestures and haptics—features not yet fully realized. It is crucial to ensure robots can communicate inclusively, addressing needs of people with disabilities and adapting to different languages and response times.

Expanding Beyond Industrial Use

Effective human-robot interaction is vital for humanoids to move from industrial settings into hospitals, elder care, and homes. Robots working with vulnerable populations must be programmed to foster safety and comfort during interactions.

Recommendations and Future Directions

The IEEE group suggests enabling human override, standardizing visual and auditory cues, and aligning robot appearance with capabilities to avoid misleading users. Clear guidelines will help manufacturers, regulators, and users understand and trust humanoid robots. While standards development is complex and consensus may be challenging, establishing a minimum safety bar is essential for industry progress and public confidence.

Standards will facilitate trust, ease international market entry, and assist regulatory frameworks. As the field evolves, ongoing collaboration among stakeholders will be critical to balance innovation with safety.