Futuristic factory floor with humans and robots collaborating seamlessly.

Safer Robots, Happier Humans: How Sensor-Free Tech Could Revolutionize Workplace Safety

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Theo Raines in Tech & Innovation August 2025 • 4 min read.

"Unlock the potential of collaborative robots with groundbreaking sensor-less force detection for safer, more intuitive human-robot interactions."


Imagine a factory floor where robots and humans work side-by-side, seamlessly collaborating to assemble products, move materials, and perform intricate tasks. This vision of human-robot collaboration (HRC) is rapidly becoming a reality, promising increased efficiency, improved safety, and a more engaging work environment. But to truly unlock the potential of HRC, we need robots that can sense and respond to their human partners in a safe and intuitive way.

Traditionally, achieving this level of responsiveness has required equipping robots with a variety of external sensors, such as force/torque sensors, tactile sensors, and vision systems. These sensors provide robots with the data they need to detect human presence, understand human intent, and react appropriately to unexpected contact. However, adding these sensors can be costly, complex, and difficult to integrate into existing robotic systems.

Now, a groundbreaking new approach is emerging that eliminates the need for external sensors altogether. This sensor-less force detection technology uses sophisticated algorithms and dynamic models to allow robots to "feel" their environment and detect external forces without relying on additional hardware. This innovative approach promises to make collaborative robots more accessible, affordable, and adaptable, paving the way for a new era of human-robot collaboration.

Why Sensor-less Force Detection is a Game-Changer for Industrial Robots

Futuristic factory floor with humans and robots collaborating seamlessly.

The core idea behind sensor-less force detection is to leverage the robot's existing internal sensors – such as joint position sensors and actuator current/torque sensors – to infer information about external forces acting on the robot. By analyzing the data from these sensors in conjunction with a detailed dynamic model of the robot, it's possible to estimate the magnitude and direction of external forces without the need for dedicated force sensors.

Here's how this technology works in practice:

  • Dynamic Modeling: A detailed dynamic model of the robot is created, capturing its inertial properties, friction characteristics, and other relevant parameters.
  • Parameter Identification: The parameters of the dynamic model are identified using advanced algorithms and experimental data.
  • Torque Residual Analysis: The difference between the predicted torque (based on the dynamic model) and the measured torque (from the robot's internal sensors) is analyzed to estimate external forces.
  • Threshold Detection: A threshold is set to distinguish between normal operating forces and external forces that may indicate human contact.
When an external force is detected, the robot can respond in a variety of ways, such as stopping its motion, adjusting its trajectory, or alerting a human operator. This allows the robot to work safely and collaboratively with humans in a shared workspace.

The Future of Human-Robot Collaboration is Sensor-Free

Sensor-less force detection technology has the potential to revolutionize human-robot collaboration, making industrial robots safer, more adaptable, and more accessible. By eliminating the need for external sensors, this innovative approach reduces costs, simplifies integration, and opens up new possibilities for collaborative manufacturing, assembly, and other industrial applications. As the technology continues to develop and mature, we can expect to see sensor-less force detection playing an increasingly important role in the future of human-robot collaboration, creating safer and more efficient workplaces for everyone.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1007/s12206-018-0939-5, Alternate LINK

Title: Sensor-Less External Force Detection For Industrial Manipulators To Facilitate Physical Human-Robot Interaction

Subject: Mechanical Engineering

Journal: Journal of Mechanical Science and Technology

Publisher: Springer Science and Business Media LLC

Authors: Bitao Yao, Zude Zhou, Lihui Wang, Wenjun Xu, Quan Liu

Published: 2018-10-01

Everything You Need To Know

1

How does sensor-less force detection actually work to allow a robot to 'feel' its environment?

Sensor-less force detection leverages a robot's internal sensors, like joint position sensors and actuator current/torque sensors, along with a detailed dynamic model, to infer external forces. By analyzing the difference between predicted and measured torque—torque residual analysis—it estimates the magnitude and direction of these forces without needing extra hardware. This is crucial for safety.

2

How does sensor-less force detection compare to traditional methods that use external sensors?

Traditional collaborative robots rely on external sensors such as force/torque sensors, tactile sensors, and vision systems to perceive their environment and react to human interaction. Sensor-less force detection eliminates the need for these external sensors, reducing costs and simplifying integration. This enhances accessibility and adaptability compared to older systems.

3

What are the key steps involved in sensor-less force detection?

The four key steps are: Dynamic Modeling (creating a detailed model of the robot's physical properties), Parameter Identification (refining the model with experimental data), Torque Residual Analysis (comparing predicted and actual torque to estimate external forces), and Threshold Detection (setting a limit to differentiate between normal and unexpected forces).

4

What happens when a collaborative robot using sensor-less force detection detects an external force?

When an external force is detected, the robot can respond in various ways: halting its motion, adjusting its planned path (trajectory), or signaling a human operator. This adaptability ensures that the robot can work safely alongside humans in a shared workspace. Without detection it could cause harm to humans.

5

What are the expected implications of sensor-less force detection on the future of human-robot collaboration in industrial settings?

The adoption of sensor-less force detection is expected to greatly improve safety, adaptability, and accessibility of industrial robots. By reducing costs and simplifying integration, it paves the way for wider use of collaborative robots in manufacturing, assembly, and other sectors. This shift promises safer and more efficient workplaces, making human-robot collaboration a more practical reality.

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