Is it really safe to share workspace between robots and humans? Robotnik in the HR-RECYCLER project

Industry 4.0 and smart factories are a favorable framework for companies that want to grow. Technological sector, particularly collaborative robotics, is always developing to respond to the new challenges that this context presents.

New challenges

As Ángel Soriano said in this interview, ‘one of the main challenges we face in the development of R&D projects are the dynamic and unpredictable environments. It is one of the most critical factors when offering a solution applicable to different scenarios or use cases'.

Faced with these changing and dynamic scenarios, it is necessary to offer maximum safety so that robots and humans can operate with full guarantees.

This post shows how speed adapts to the environment so that the robot accomplishes its mission as quickly as possible while maintaining system safety.
Today's AMRs are more powerful, more advanced and more productive, so safety has become a critical element and the key challenge for effective collaboration with workers.

HR-Recycler is an H2020 R&D project developing a hybrid human-robot recycling plant for the recycling of electrical and electronic equipment.
Robotnik, as hardware supplier, is in charge of developing new UAV concepts capable of handling material inside smart factories and pre-processing WEEE materials by automatic robotic procedures (categorization of electrical/electronic devices, disassembly, sorting of device components, etc.).

Safety is the key

For Robotnik, as an experienced robot manufacturer since 2002 and within the collaborative environment of the HR-Recycler project, this aspect is especially important as humans and robots will be working side by side.

Previous posts discuss the importance of safety focusing on the predictive/anticipatory side, i.e., signaling and how it is implemented in AMR's. Safety also involves aspects such as collision avoidance, slowing down or stopping robots and the comfort of humans when an AMR is working around them.

But, how does this really work? How is Robotnik ensuring the safety of its robots?

Robotnik aims to ensure its robots through the accomplishment of the EN ISO 3691-4:2020, that is related to Industrial trucks — Safety requirements and verification — Part 4: Driverless industrial trucks and their systems.

For the accomplishment of the normative and besides the concrete reglaments of each country, this post gives to the reader a brief description about what, why and how the related to motion set of premises of the ISO will be reached.

At first, the robot should be properly designed to allow the system to reduce the velocity, stop the motion or modify its behaviour according to the environmental conditions, as it is included in the ISO mentioned above, the minimal hardware requirements in terms of ensuring the motion are:

  • Braking system: The robot needs to be equipped with a braking system able to work when the robot is switched off and also able to stop the system when actuators are out of control.
  • Speed control system: The robot needs to be equipped with a speed monitor system to send a stopping signal in case of overspeed. It also needs to be aligned and compliant with the stability of the platform.
  • Steering control system: The robot needs to control the steering angle of the actuators to monitor the stability of the robot.
  • Protective devices and complementary measures: To detect persons in the routes in automatic mode, the robots must be equipped with sensors that can detect persons and correctly installed to do that. If these devices cannot work in the movement direction the maximum velocity must be less than 0.3 m/s.

Once this part is already installed in the robot and properly integrated, the configuration and the control areas must be aligned with the robot capabilities. In order to check all the components, the robots have installed the safe PLC module, an adjustable modular safety controller for safety applications and the kernel of the monitoring process. The safety level actually achieved is determined by the external wiring, how the wiring is implemented, the configuration, the selection of command triggers, and how they are arranged on the machine.

In Robotnik’s robots, the wired and interaction direction goes as follows:




The safe PLC communicates with the electromechanical brakes in order to trigger the safety and stop or reduce the velocity of the robot. The configuration depends on the design, function and working area of the robot. If personnel can access the shuttle path, certain safety conditions must be implemented in accordance with applicable standards so the robot must be able to update this safety level in real time:

  • Laser areas: The used laser scanners can switch between two kinds of areas: the warning area, where the robot reduces its maximum velocity as a prevention; and the protective field where the robot stops its behaviour if something shuts it. Both fields are configured to increase proportionally to the velocity. The minimum distance of the protective field for the lowest maximum speed limit is 0.3m.
  • Speed limit: The velocity limits are included as one of the conditions in the ISO to ensure that the robot will be able to stop before crashing and with a remaining distance, the limits can also be lowered to improve the stability of the base or load. The maximum velocity allowed must be less than 0.3m/s if the personnel detection systems (i.e. the laser scanners) are muted and only can be used by the specialized workers. If the robot is not working closer to people and it has large space to work the maximum speed is 1.2m/s with the personnel detection system active. The all-possible velocity cases are summarized in the following table:

speed limit table

  • Steering angle: The direction of motion is also one of the conditions since the stability can be affected or the robot may have areas not covered by the safety.


Specific configuration

Two types of robots were designed for this project

  • RB-KAIROS+, an omnidirectional platform mounted with a manipulator
  • RB-ARES, a robotic pallet-truck

RB-KAIROS+ configuration has safety brakes, two accessible emergency buttons, a traction monitor system on each wheel and two 2D lasers installed and located in two of its corners. Scanners give the robot a 360º vision range of its environment. The vision range detects any obstacle located at a height of 170 mm from the ground that is the recommended height to detect the legs of the personnel. RB-KAIROS+ is configured, as standard, to activate the emergency stop by detecting an obstacle at a distance of 1000 mm. This configuration can be modified according to the environment or application to be carried out, as long as it does not compromise the safety of the users.


The robot has a predefined safety zone on the horizontal plane, determined by safety lasers detection. When an obstacle or a person is detected inside the safety zone, the RB-KAIROS+ will stop until the area is free again. The size of the safety zone depends on the speed of the mobile base:

When the base is static or has a speed below 0.15 m/s, the safety zone is the one detailed in the scheme below:

This area increases with the mobile base speed until reaching the maximum dimensions with a speed of 1m/s:

Once the maximum speed of 1.3m/s is reached, the platform stops for safety reasons.

The pallet-truck, it is configured with the safety brakes, the steering and traction monitoring system and one single 2D laser installed and located in the front shape, which gives it a 270º vision range. The vision range detects any obstacle located at a height of 170 mm from the ground and it is configured to activate the emergency stop by detecting an obstacle at a distance of 250 mm.


You can see how the robot has a predefined safety zone on the horizontal plane, determined by safety laser detection. The size of the safety zone depends on the speed vector of the mobile base, that is, its module, sense and direction of motion. Several small regions are defined and only the ones that are in the direction and sense of the motion vector are active.

safety zone

When the base is static or has a speed below 0.15 m/s, the safety zone is the one detailed in the scheme below:

This area increases with the mobile base speed until reaching the maximum dimensions with a speed of 1.2m/s:


Safety is a crucial part that must be taken into account when designing an AMR that works in a collaborative scenario between humans and robots. Robotnik works to achieve a total synergy between components to build, develop robots capable of working safely between humans. This will represent an efficient and cost-effective solution for the company that bets on implementing robotics.



industry 4.0

Mobile robots and safety: the experience of Robotnik in HR-RECYCLER project

Collaborative robots have come front and center on the international stage as they’ve become widespread in Industry 4.0. Today we have more powerful, more advanced and more productive robots, so safety has become a key element.

Safety is the key

For Robotnik, as an experimented robot manufacturer and within the collaborative environment of the HR-Recycler project, this aspect is especially important since humans and robots will be working side by side. The solution proposed to routing materials inside a factory has to be done in a safe manner, in this case, the robots designed are the RB-KAIROS+ (mobile robotic manipulator) and the RB-ARES (pallet truck). It’s really important how the mobile robots  will show the intention of motion, elevate or manipulation.  

industry 4.0


To ensure the correct operation within the complex framework of this project, Robotnik has equipped its robots with sensors and signalers that allow the robot to proceed safely and show its intentions in advance. 

There are a number of ways manufacturers can introduce safety measures in their automated operations. The type and complexity of these safety measures will vary by the robotic application, with the aim to make the mobile robot safer, there are certain safety rules and standards that these collaborative robots must comply with, in Europe are found in EN ISO 3691-4:2020 and ISO 12100:2010 6.4.3

rb-ares mobile robot

Clarifying the ISO standard

This post aims to give to the reader a brief description about what, why and how all the premises of the ISO will be reached.

First of all, what does the normative include? The standards on warning systems say:

  1. When any movement begins after a stop condition of more than 10 seconds, a visible or acoustic warning signal will be activated for at least 2 seconds before the start of the movement.
  2. A visible or acoustic warning signal will be activated during any movement.
  3. If the human detection means are active, the signal will be different.
  4. When robots change their direction from a straight path, a visible indication will be given of the direction to take before the direction changes in case that the robot is driving autonomously.
  5. When the lift is active, there must be special signage.

The solution proposed is a two-steps software that will manage the signals of the robot, explained after the diagram and on red cells:

The robot_local_control is a manager node, it has information about the status of the whole robot, that is, status of the elevator, goal active, mission ended, etc. On the right side, a group of nodes that manages the movement of the robot with a level of priority:

  • Robotnik_pad_node:  The worker uses a PS4 pad to control the robot and this node will transmit the orders, non autonomous mode. 
  • Path planning nodes: like Move_base, it controls the robot and we speak of it as autonomous mode.

Robotnik has installed on its mobile robots  two ways to alert facility users, acoustic devices or light indicators through the acoustic_safety_driver and leds_driver.

industry 4.0

As you can see, there are two steps to link the top and bottom parts, a node to transform the movement into signals to show the intention of the robot and another one to orchestrate the both signal types and manage the requirements of the normative. 

A turn signal controller is intended to solve the first and fourth requirements of the regulation depending on the mode of the robot (autonomous or non-autonomous). 

In non autonomous mode, and as the norm says, the motion depends on an appropriately authorised and trained personnel so it is enough to show that the robot is moving by reading the movement command and checking the velocity applied. 

In autonomous mode the robot navigates to a goal point through a path calculated by the planner, furthermore it manages the AMR to avoid obstacles dynamically and for this reason it is important to alert workers every moment.

What is the process?

This is a very brief description of the function, it bears the plan in mind and recalculates at the same time that the planner does just to be able to show the most up-to-date prediction of motion.

Last but not least, the robot_signal_manager aims to solve the rest of the problems since it has access to the robot status, it shows a light signaling or an acoustic signal 2 seconds before the motion, it gives priority to the emergency signals (consistent with the behaviour of the robot, red signals means that the robot will be stopped) and the signals that are not exclusive are showed using beacons or acoustic signals.

The occupied zone is one of the non exclusive signals, robots have some extra beacons that blinks on red when there is something on the protective zone (close to the intention of motion of the robot, inside the critic zone) and on yellow when there is something on the warning zone (near the protective zone).



Safety is not only stopping the robot or avoiding a crash when human-robot collaboration takes place. With the development of these nodes Robotnik aims not only to decrease the probability of accident or comply with the safety ISO premises, but also to help workers feel more comfortable with the mobile robot’s decisions and bring human-robot collaboration closer, showing clear signals about how the robot will perform.


Prosthetic research with Barrett Hands and WAM arms

A hand with a sense of touch it's something that amputees and prosthetic hand researchers have been acutely aware of for a long time, but creating robotic hands with a this kind of sense isn't trivial.

Veronica Santos, PhD in UCLA, is performing a research to advance prosthetic hands and arms and make them feel like a native limb. Santos is constructing a language of touch that a computer and a human can both understand by using SynTouch's BioTac® sensors to explore objects of varied shapes, sizes and textures, and using BarrettHands on a pair of force-controlled WAM™ arms from Barrett Technology to control these explorations.

Meanwhile, Case Western Reserve University researcher Dustin Tyler, PhD is also working on technology to advance prosthetic hands. His research focuses on the seamless transmission of sensory data to amputees. By implanting electrodes that encircle nerves, data from sensors on prosthetic hands can be transmitted to the brain.

NAO News

UNCW formed a new autism research committee to explore how the ‘Humanoids' may be used to help autistic children socialize and learn basic skills.

According to UNCW, the committee is composed of researchers from the education, computer science, and economics department, and TEACCH Autism Program at UNC Chapel Hill, in collaboration with the UNCW Watson School of Education's Assistive Technology Demonstration and Lending Site.

The university used federal grant funds to purchase the six robots from Aldebaran Robotics.


Robotnik is a new member of EURON, the "European Robotics Research Network" .

EURON is a community of people with a common interest: robots. Its purpose is to bring together the best groups and resources in research, industry and education in Europe and to demonstrate Europe's world class position in robotics.