Human-robot collaborative robots have become a huge hit in the past year.
People have long been troubled by the fact that while the robot concept is good, it is hard to apply widely. All the robots in the world together number only in the hundreds of thousands — that hardly looks like a big market.
Human-robot collaboration seems like a golden key that opens another door: as long as we can make robots safe enough for humans and robots to coexist, the barriers to robot application will be removed, and the massive market will explode overnight.
Really? What exactly is this heavenly gift called human-robot collaboration?
The concept of the collaborative robot (Collaborative Robot) actually appeared a very long time ago.
Compared with humans, robots have enormous advantages in power, repeatability and so on, which is why they are widely used in automotive and other industrial fields. But the vast majority of robots are "open-loop control systems" with almost no system feedback such as touch, hearing or vision — completely soulless beasts. To protect operators, robots must be kept in cages. That's normal — almost all high-power equipment has protective measures: car engines are isolated in engine compartments, and machine tools are enclosed in metal housings. Robots must be protected by enclosed fencing while working.
For some jobs such as loading and unloading, if the material isn't regular, robots can't pick and place it easily. Using vision or other means is too costly or technically infeasible (random bin picking, multi-type material picking). Manual loading/unloading is more economical. But safety regulations require the following process:
- Manually stop the robot before entering its work area
- The operator enters the robot work area
- Complete the loading/unloading work
- Leave the robot work area
- Manually enable the robot to continue working
This process is complicated, inefficient and error-prone. One slip means a safety accident.
To ensure safety, the ISO 10218 standard was issued, providing a series of guidelines and recommendations. Engineers monitor human behavior through vision, laser and other means, and determine protective actions based on safety zone divisions — such as automatically slowing the robot down, reducing power, or disabling enablement. Once a human enters the danger zone, the robot must come to a complete stop.
These operations are the earliest "collaborative operations" of human-robot collaboration.
Many people think the protective measures above are too conservative. Humans and robots may coexist in the same space, but they can't work together. The biggest concern is that robots are too rough and can easily injure people.
So new thinking developed along several lines:
- Assess the human body's tolerance for injury and determine levels. For example, the buttocks and the eyes can certainly tolerate different levels of harm.
- Assess and improve the robot body, end effector and external environment — for example, avoid sharp tooling and add soft protective materials to robot surfaces.
- Based on the assessment, calculate the maximum speed, power, torque and other values at which the robot won't harm humans in a specific environment, and control the robot's speed and distance accordingly.
- When humans and robots coexist and work collaboratively, the robot uses protective actions; once the human leaves the collaboration zone, the robot can automatically resume full-speed operation.
- Use anti-collision, drag teaching and other means for human-robot collaboration.
The above improvements are standardized by ISO 15066 (Robots and robotic devices — Collaborative robots).
This protocol is still at the TS stage and has not yet become an ISO standard. Several problems can be seen from the above description:
- Human-robot collaboration is a systems engineering problem, not just a robot problem. No matter how safe a robot is, if you mount a dagger on its end effector, it still can't do "human-robot collaboration". Therefore, a comprehensive assessment (Risk Assessment) of the external environment and tools is needed.
- The algorithms for environmental assessment are complex and hard to implement. Even with calculation results, they are difficult to execute reliably without errors.
So what to do? Smart people of course simplify the problem: limit the robot's absolute speed and torque to ensure it won't hurt people in most working conditions, skip the environment assessment, and elevate the role of anti-collision and drag teaching.
And so UR burst onto the scene, sparking a wave of human-robot collaboration.
UR-like robots became synonymous with collaborative robots.
But if we trace back to the root, we find that UR is just a simplified version of the human-robot collaboration model. Human-robot collaboration is essentially a systems engineering problem that requires detailed environmental assessment and control through advanced closed-loop control technology. Therefore, multi-sensor technology and compliant control algorithms are the real core of human-robot collaboration. As long as the control means are in place, even traditional industrial robots as massive as steel giants can achieve human-robot collaboration.
The iNexBot control system has independently developed control algorithms and supports all the key technologies required by collaborative robots. We are willing to build the future world of human-robot collaboration together with our customers!
- Intelligent vision (2D/3D)/force-controlled sensor control and distance sensing
- Anti-collision
- Drag teaching
- Safety models and assessment algorithms
