Cobot? Introduction how safety is assured for people, robots and machines

Can people and machines or robots really collaborate?!

What are collaborative robots?

A cobot is a robot that operates in the same space with a person. In recent years, robots have been developed that can pick up and carry objects without help from people.

Mr. Hashimoto:The industrial robots we looked at last time mostly operate in spaces that people can’t enter, such as behind a safety fence. But a cobot is designed to be stop immidiately if it touches,collides with a person or obstacle by sensors depends on the strength of external force. As a result, the risk of injury is reduced so that it could be operated in the same place with person.

Ms. Hama:We belive we could increase productivity by working with industrial robots under the recent low birth rate and labor shrtage situation.

What about safety measures for people, robots and machines during emergencies?

Ms. Hama:It’s wonderful that we can work alongside robots, but isn't it danger when the power fail down or some other emergency happen?

Mr. Hashimoto:： That’s right. Countermeasures in the case of an emergency are set out in JIS (B 8433-1:2015).

• Robots must have at least one emergency stop function
• Robots must have an emergency stop function that can be operated manually
[Ref.] JIS standards https://kikakurui.com/b8/B8433-1-2015-01.html

TThis standard requires robots be designed harmless to people with safety systems that could detect any impacts on it. Emergency brake(▶ spring-actuated brakes) is one of major method for this standard! I described as one of the key elements in robots.

Spring-actuated brakes ensuring safety for people, robots and machines

What are Spring-Actuated Brakes?

A spring-actuated brake is an emergency brake that operates when the electricity is cut off.
* See here for details ▶ What Are Electromagnetic Clutches and Electromagnetic Brakes?

What is the situation when spring-actuated brakes used?

Ms. Hama:In case ofindustrial robots, what is the situation when spring-actuated brake be used?

Mr. Hashimoto:Spring-actuated brakes are used in case of emergency stop. During an emergency stop, the spring-actuated brakes operate and the robot’s joints are locked. In this way, we can prevent any risk that the robot arm will hit a person or another machine.

Ms. Hama:Assured to know that the safety measures work perfectly. Spring-actuated brakes are absolutely necessary for robots. By the way, one of the senior engineers was telling me about their methods for making spring-actuated brakes smaller and lighter while still increasing the torque. That would work really well in robots. I need to study more to catch up with the senior engineers!