Cubic-S safety module in a palletising application with a Kawasaki Robotics RD080N robot

The EtE Pallet robotic palletising system is an example of a high-performance solution combining a conveyor system, a Kawasaki Robotics RD080N robot equipped with a gripper, and software which allows the operator to define palletising patterns. This makes it possible to create customised layouts for boxes depending on the order to be executed.

High-performance palletising system with a Kawasaki Robotics RD080N robot

The Kawasaki Robotics RD080N 5-axis robot is dedicated to palletising. It is designed to achieve high movement speeds and consequently higher productivity during operation.?

Watch the video showing the palletising system:

The Kawasaki Robotics RD080N robot is equipped with a mechanical gripper to pick up boxes of different sizes.?

To pick up the pallets from the buffer area, the gripper uses a scissor clamp mechanism - allowing the pallet to be picked up and transferred to the conveyor roller.?

Depending on the programmed pattern, a cardboard spacer is placed on the bottom of the pallet and between the laers. The gripper picks it up using vacuum suction cups. The actual gripper sequence is controlled by an IO board which communicates with the robot via standard Ethernet IP protocol.

An MiR 500 mobile industrial robot is used for transporting the pallet with cardboard spacers to the workstation. A docking station is mounted in the right-hand corner of the workstation, where the robot waits for a task and loads itself.?

When the application is started, the PLC sends a mission to the MIR, which starts to execute. In the demo application, the robot performs 4 missions. Safety system is the most important element of any robot workstation. Dedicated systems ensure safe work within the workstation.

A module that ensures the safety of the Cubic-S system

System security is ensured by a safety light curtain and a safety scanner mounted on the fence. The scanner defines safe zones, which are controlled by the PLC. This makes it possible to suspend monitoring of a selected zone of the workstation in which the MIR robot is moving.?

The large number of components and the high density of the workstation components make it easy to see how the Cubic-S safety system supplied by Kawasaki Robotics works.?

What safety issues does the use of the Cubic-S system ensure?

1. Defined zones of movement

The work area is smaller in relation to the robot's range of motion, which may cause the robot to collide with the parts, fence or ceiling. In addition, the workstation has many objects sticking out, such as roller conveyors, pallet magazines and auxiliary constructions, which the robot could accidentally touch while moving.?

Such collisions can also occur during the process of teaching points and setting trajectories. A solution to this problem could be to mechanically limit the movement of the robot on a particular axis or to set a software limit on the movement of an axis.?

However, this requires the use and control of additional elements. The Cubic-S module solves this issue with its ability to define one zone in which the robot is allowed to move and up to eight zones in which the robot is absolutely not allowed to move. An additional advantage of this solution is the control not only of the TCP (Tool Center Point) but also of the geometry of the entire arm and tool.

2. Cubic-S communication with external safety components

From time to time, an MiR mobile industrial robot enters the workstation with a supply of pallets or spacers. This requires a design of a partially open work area, which potentially poses a risk of a person entering the danger zone.?

It would be possible to use standard light curtains to detect intrusion into the work zone or the entry of a mobile industrial robot, but this would result in a complete stop of the robot, thus reducing productivity. ?

The Cubic-S module has the ability to communicate with a 2D or 3D scanner that checks the required zone and transmits the appropriate signals to the controller. Using the Cubic-S module has made it possible to temporarily switch off the scanning of the area in which the mobile industrial robot is moving.?This allows the station to operate continuously. Two protocols are available for communication: Ethernet/IP Safety or I/O communication.?

3. Dynamically prohibited and allowed zones

When a mobile industrial robot exchanges pallets with materials, more zones appear at the workstation which the robot should not be able to enter, which causes problems in defining fixed allowed and forbidden zones.?

To prevent picking up items from the exchanged pallets, it is possible to use external sensors or a master system that manages the executed motion sequences.?

In this case, a simpler way to implement is to use Cubic-s function with dynamically forbidden or allowed zones. It is possible to define 4 such zones.?

When the mobile industrial robot enters the zone, it is deactivated and the robot is not allowed to move there. This function is handled by the inputs/outputs built into the Cubic-S module.

4. Extensive configuration options

In addition to the workstation handling the supply of items for palletising, it also sends out the ready-packed pallet. The main conveyor belt with integrated reflective sensors and an optical curtain is used for this. These sensors control whether someone is trying to get in from outside and also whether the pallet is ready for transport to the next station.?

The Cubic-S module can work with all safety devices designed for robotic workstations, and extensive configuration options allow the curtain to be switched off at the pallet exit while the optical sensors detect the ready pallet being transported to next station. When the entire pallet leaves the station, the safety curtain is immediately reactivated.

5. Speed monitoring function

When a mobile industrial robot moves inside a workstation or a finished pallet is moved out, there are many parts that move around in the workstation. Without a vision system, the robot cannot determine the position of all the moving parts. In addition, there is the risk that a person may try to enter the robot's working area while the scanners are turned off for this brief moment.?

To provide a higher degree of safety, a speed monitoring function is also used when any of the safety curtains are switched off. The robot then slows down to a safe speed and the system supervises that it does not accelerate until all safety curtains are switched on again.

This is just one application where the Kawasaki Robotics Cubic-S module has a major role in ensuring the safety and stable operation of the robot. In addition, extra safety buttons can be connected to the Cubic-S module and options can be enabled that also control tool orientation and the angles of individual axes. Using Cubic-S reduces the amount of safety equipment used. The module itself has TüV certification and provides category 3 safety.

Contact

Feel free to contact our specialist Konrad Sendrowicz, who is the Technical Support Engineer at Kawasaki Robotics Central and Eastern Europe HUB. Please visit www.kawasakirobotics.pl/en to learn more about Kawasaki Robotics.