The solution
APA proposed the adjustment of the existing manual work infrastructure by replacing human with a robot, for the most non-ergonomic activities. This was achieved by using a 6-axis FANUC robot with Cognex and Keyence 2D vision systems. Human safety was monitored by SICK security scanners and Efaflex digital gateways. Thanks to these steps, work on this position has gained the title of ‘worthy of a king’ among the employees.
The work as a wheel reloading operator was very unrewarding. There were two main tasks for the employee:
- transporting boxes containing 30 - 36 car wheels with a forklift truck from the unloading room to the assembly room,
- loading of each wheel with a manual manipulator onto a roll conveyor.
While the first of these tasks did not pose any major problems, the second one was extremely tiring both physically and mentally for the employee (mainly due to the exorbitant cycle time - the employee had about 18 seconds to reload each wheel). Such a situation resulted in trade union being often interested in this position, and employees working unreliably. Bizzare situations occurred when the operator had to take care of his physiological needs and could not leave his workstation as this would cause production stoppage. Due to such situations, the client decided to implement solutions that would help reduce these problems, but at the same time the budget assumed a low-cost nature of the project. In such conditions, there was no question of automation of the entire process of wheel transport from the unloading hall, but only adapting the existing manual workstation to work with the robot.
There are a few questions to be answered connected with the last assumption:
- How will the robot recognize the position and number of wheels in the container?
- How to ensure that the correct sequence of wheels is maintained, with 100% efficiency?
- How should the gripper look like? One that would be able to operate while detecting errors in position of the wheel, and in case of major errors – sense a conflict.
- How are all the elements of the station to be positioned, taking into account the restrictive constraints of the building conditions?
In response to these and many other questions, a solution has been proposed: a FANUC robot with a Cognex camera on its flange, together with an light tube, a Keyence laser rangefinder, and a bendable gripper to detect a conflict – our own design. For the time of the container swap, an Efaflex remote control gate and a Cognex automatic barcode scanner were available to the forklift operator. The whole process was visualized on a large 19" Siemens HMI panel. The S7-400 controller, also by Siemens, was responsible for safety control and management.
Benefits
The client's need has been met in 100% and his objectives have been achieved. The main objective of the project was to increase the ergonomics of work at the workstation by eliminating manual work with a manipulator, which caused a great strain on the spine of the operator, and reduced motivation for earnest work among employees. Due to APA’s solution, the operator at the station no longer has to ask anybody if there is a possibility to take care of his physiological needs. Thanks to this kind of ‘relief’, trade unions are no longer interested in this area. Moreover, human errors consisting in scanning wrong barcodes and confusing the correct sequence of wheels have been eliminated - thanks to the verification with the current queue of cars to which the wheels are mounted.
Fun fact
- The FANUC robot has come an interesting way: Japonia -> Niemcy -> Poznań -> Gliwice -> Poznań -> Gliwice -> Poznań.
Technologies used
- Profinet/Profisafe
- 2D vision system (CognexInsight) + laser rangefinder (Keyence) for 3D recognition
- CognexDataman barcode scanner
- Simatic PLC S7-400
- TIA Portal (HMI)
- FANUC Roboguide - software for CAD analysis and offline robot programming
- SICK laser security scanners
- Efaflex high-speed doors
- FANUC 6-axis robot with R-30iB controller and VASS standard