Safety sensors create harmonized workspaces for robots and humans

Both internal and external safety sensors have enabled human operators and collaborative robots to work together safely in the same space.

In an automated factory, robots and humans frequently work together in the same space. Without sensors, robots had the potential to collide with human workers, with some factories using guards and other protective devices to ensure safety. Now with the help of several different sensors, collaborative robots or “cobots” are able to detect abnormal activities through force limitation and vision monitoring, allowing humans and robots to work together in the same space without incident.

Most cobots nowadays are designed to limit power and force. When a cobot detects a certain level of power or force, it stops automatically to protect the human operator.

“Due to the safety functions for motion, speed, force and power monitoring, the human and robot system can move at the same time in the same workspace,” said Adam Sobieski, General Manager of Universal Robots Greater China.

Universal Robots owns more than 65 patents related to cobots,in areas such as robot construction, trajectory control, robot calibration, robot safety and robot programming. For instance, the company’s e-series robots, launched in June 2018, have a built-in force-torque sensor and other safety functions for industrial use.

“Regardless of technology, safety sensing needs to meet the required functional safety and the application is required to be verified and validated,” said Sobieski.

External sensors for safety

For industrial safety, sensors are also used outside of cobots.

“In order to use the speed and separation monitoring method, external safety devices such as a safety scanner have been used to lower speed as a person approaches the collaborative workspace,” said Sobieski.

A capacitive sensor is used to measure the distance between a human and a robot; and an optoelectronic sensor is able to provide optimum protection for machinery when there is active intervention into the production process. Examples of this include light barriers and safety laser scanners.

"Today, production is very agile, that is to say it changes rapidly. Therefore, flexible and adaptable sensors are needed,” said Roger Wang, Senior Service and Product Technical Manager at Pilz Taiwan.

In order to fulfill the increasing need for a variety of different sensors in factories, Pilz has developed its sensor technology into intelligent systems that can be used to implement a wide range of solutions.

“Whether mechanical, magnetic, RFID, optical or camera-based: productivity and user-friendliness are always in the focus of our safety sensors,” said Wang. “Our solutions are individually expandable, so that companies can profit from a high flexibility.”

Positive market growth

“The market for safety sensors in industrial automation presents lucrative growth opportunities owing to compliance with mandated quality and safety standards ,such as OSHA and ISO series certifications, enabling the industrial enterprise to earn accreditation in regards to optimal operations sustainability model enabling welfare of human labor force, utilities and resources, savings on maintenance and repair expenditures eventually safeguarding the company from accidents or major catastrophes,” said Nikhil Kaitwade, Research Manager at Future Market Insights.

Kaitwade suggested that with the establishment of new industrial facilities, the safety sensor market and its associated growth would increase manifold in emerging regions and territories.

“Quantifying the growth scenario, the market is expected to witness a robust growth (CAGR over 10 percent) in the forthcoming decade,” said Kaitwade.