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How 11 cobots help assemble the Fiat 500 electric car

UR Cobots FIAT 500

Stellantis N.V. is a Dutch multinational automobile manufacturer established through a merger between PSA and Fiat Chrysler Automobiles. The company installed 11 collaborative robot arms from Universal Robots (UR) at its Mirafiori factory in Turin, Italy, to automate a series of complex assembly line operations and quality controls for the new Fiat 500 electric car.

The collaborative applications developed at Mirafiori have delivered significant benefits in terms of operating precision and quality, and also improved the ergonomics of a series of operations previously performed manually.

Challenge

On the Fiat 500 electric car production line, some of the assembly processes and quality controls required the introduction of specific automation technologies to ensure the quality and repeatability needed to meet product standards. Additionally, given the fairly high average age of the factory workers, the question of ergonomic well-being was also an issue.

Solution

Stellantis decided to adopt UR cobots robots some years ago. Collaborative automation has freed operators from repetitive and physically demanding manual tasks, so that they can be employed on processes with greater added value.

The 11 UR cobots now automate the following applications:

  • Application of the waterproof liner to the vehicle doors (2 UR10e cobots working in parallel)
  • Positioning of the soft-top (activation of the primer track and visual inspection to ensure the correct extrusion of the adhesive band around the perimeter) (1 UR10e)
  • Check on soft-top frame dimensions (1 UR10e)
  • Riveting of the tailgate with blind rivets press-set on the boot frame (1 UR10e)
  • Hood mounting (1 UR10)
  • Tightening of the rear side-door hinges (1 UR10)
  • Mudguard mounting (2 UR5 and 2 UR10 cobots)

The UR cobots at the Mirafiori factory were rolled out gradually to enable the operators to fully understand how the automated processes worked.

“As a first step, we decided to introduce a UR cobot in the company canteen, distributing glasses of water to employees during the lunch break,” Mirafiori plant manager Luigi Barbieri said. “This gave the line workers the opportunity to see the safety and collaborative nature of the cobots for themselves, and overcome any apprehensions about the safety of the subsequent applications.”

Results

After the success of this initial trial, the UR cobots were installed on a series of applications on the 500 electric car production line:

Application of the waterproof liner to the vehicle doors: Two UR10e cobots operate in parallel on the door assembly line. A vision system registers the arrival of the door and activates the cobot, which uses a roller attached to its wrist to apply constant pressure on the fabric, applying it on the door panel.

The application is particularly challenging because it requires the cobot to follow a complex path within a confined space, avoiding the panel’s push pin protrusions and ensuring that the liner is completely sealed to prevent the infiltration of water. The cobots work with millimetric precision, guaranteeing a repeatability of +/- 0.05 mm.

“The UR cobot has significantly improved the ergonomics of this application,” said ergonomics specialist Giuseppe Guidone. “The application of the liner required the operator to apply constant pressure using a dynamometric roller, a task that over the long term could damage the arm joints and cause musculoskeletal disease. So the cobot has brought two benefits: high operating precision and quality, along with improved ergonomics and well-being for our operators.”

A UR10e cobot uses a roller attached to its wrist to apply the fabric to the door panel. | Credit: Universal Robots

Soft-top assembly
Two UR10e cobots operate on the soft-top assembly line for the Fiat cabrio 500 model. The first cobot performs two different operations; Using a pad supported by a special pick-up device, the UR10e cleans and prepares the primer track, on which the adhesive to fix the soft-top to the frame is subsequently applied. The second operation is a quality control, where a vision system checks the geometric continuity and dimensions of the adhesive band. The second cobot works in synergy with an anthropomorphic robot.

Once the soft-top has been assembled, it is opened on a special support and then picked up by the robot. At this point, the second UR cobot runs a size check (through a vision system) on the soft-top frame to ensure the conformity of the dimensions. Once conformity has been ascertained, the soft-top is removed from the line by the anthropomorphic robot.

This application offers a series of productivity and quality advantages. The cobots ensure that the adhesive extrusion is correct and check the dimensions of the soft-top frame.

Tailgate riveting
On the door assembly line for the Fiat 500 electric car, a UR10e cobot has been configured to press-set 10 blind pop rivets, which secure the boot hinge reinforcements to the boot frame. The operator loads the tailgate frame and hinge reinforcements onto the workstation, then leaves the cobot to position and press-set the rivets.

The application provides productivity and ergonomic benefits. At the same time, constant monitoring of the workstation input and output parameters ensures higher and consistent process quality.

Hood mounting
For this application, the car body reaches the workstation with the hood mounted in a closed position and the hinge screws inserted by the operators on the previous station. Once the hood geometry has been established, the cobot (a UR10) moves into position and tightens the 4 screws to the correct torque.

The main advantages of this application are quality, efficiency and ergonomics, given that the hood reaches the station in a closed position, making correct tightening extremely difficult. Since the hinge screws to be tightened are not visible, the operator could easily miss one or make an incorrect tightening. The cobot also improves the ergonomics of the operation, freeing the operators from working in uncomfortable or awkward positions.

Two UR5 and two UR10s cobots are installed on a platform that lowers itself on 
the z axis in relation to the body. The wings of the platform close to fix the geometry and 
activate the tightening operation on the 24 screws that fasten the mudguards. | Credit: Universal Robots

Extra door hinge tightening
For the Fiat 500 model featuring an extra rear side door, an automated application capable of performing a complex tightening cycle was required. With the assistance of an advanced automated tool on which the cobot is installed, the door is positioned correctly on the vehicle body. The cobot then performs the tightening operations, from the rear of the boot.

The cobot meets two different process requirements: it frees the operator from tightening the hinges in an awkward posture, where they would be unable to see the correct positions inside the car body; and it prevents the kickback from the tightening tool (which operates with a 75 Nm torque) hitting the arm of the operator.

Mudguard mounting
In this station on the sheet metal line, the frame arrives with the right and left mudguards already in position. Two UR5 and two UR10s cobots are installed on a platform that lowers itself on the z axis in relation to the body. The wings of the platform close to fix the geometry and activate the tightening operation on the 24 screws that fasten the mudguards. Each of the 4 cobots is fitted with an automatic screw gun with torque control.

The application offers various advantages. Collaborative automation guarantees ergonomic benefits for the operators (who are no longer required to work below the vehicle body). Since the screws are torque tightened, tensile stress on the sheet metal parts is eliminated. Also, the cycle time is shortened, boosting the productivity of the whole station.

The post How 11 cobots help assemble the Fiat 500 electric car appeared first on The Robot Report.

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Aerospace assembly uses vision-guided Kawasaki robots for unique cell

While many manufacturing sectors rely on automation, aerospace has been slow to adopt robotics because of low production volumes and the delicate nature of making specialized parts. One aerospace part assembler recently worked with integrator SYSTEMATIX Inc. to design a work cell for installing nutplates, which hold the skin of an aircraft to its frame.

To manage the more than 200 variations of the part, the aerospace manufacturer and integrator used high-performance robots from Kawasaki Robotics (USA) Inc. and 3D vision products.

Kawasaki case study breakdown

Challenges

Nutplates must meet strict quality requirements. For instance, the height of the rivets must be exactly the same, so human operators had to shave them down because of inconsistent rivet heights. Human error was costing the company time and generated more waste because of added process requirements.

All employees had to undergo intensive training and certification for each part they produced. They also had to document their work in real time.

In addition, the monotonous process of nutplate installation led to serious staff-retention problems for the manufacturer.

Because the aerospace manufacturer was not familiar with industrial automation, it teamed up with Waterloo, Ontario-based SYSTEMATIX. The integrator helped design an adaptable, long-term solution that could meet cycle-time requirements while identifying irregular part types in numerous configurations.

SYSTEMATIX’s vision expert used a complex, curved part to develop and test the robot sequences for locating multiple installation points. The expert then added drilling and riveting tools.

Machine vision for aerospace assembly

The aerospace manufacturer uses 3D vision with high-precision robotics. Source: SYSTEMATIX

Solution

SYSTEMATIX brought in three different Kawasaki R-series robots, as well as Matrox imaging software and LMI locators to identify 224 aerospace part types. The supplier said it chose Kawasaki robots because of its open architecture and ability to handle more advanced processes.

“I’ve touched almost every robotic arm out there,” said project leader P.J. “One reason I like Kawasaki is the ease of working with the programs, especially the AS Language. It’s one of the driving forces why we use Kawasaki.”

The first robot, a Kawasaki RS080N, determines the part position by scanning three distinctive features using 3D machine vision. After the part is aligned, the robot’s drill head end-of-arm tool (EOAT) grips the tool and drills and countersinks two rivet holes for nutplate installation.

The RS080N then releases the feature and rotates the arm to retrieve the correct rivets out of four possible lengths, and at one of two specific pitches, from the rivet slide tooling.

While the RS080N retrieves the rivets, the RS010L robot picks up a nutplate and uses vision cameras to verify that it is the right nutplate out of 28 possible types. From here, the robot places the rivet on the nutplate-locating tool.

The RS080N and RS010L must connect repeatedly without colliding, so they must be highly reliable. Kawasaki’s R-series general-purpose robots fit this criteria, with repeatability ranging from ±0.02mm to ±0.06mm (0.0007 to 0.002 in.), as payload increases from 3 kg to 80 kg (6.6 to 176.3 lb.).

Aerospace assembly uses vision-guided Kawasaki robots for unique cell

Source: Kawasaki

“The arms are very robust; they don’t wander,” P.J. said. “The arms have to go to some very exact positioning, and we’ve not had a single issue with that. They’re very precise.”

Cameras perform a vision check before placing the nutplate on the tooling to ensure it is clear to receive a new nutplate. The robot then places the nutplate on a turntable so the RS005N robot can apply Alodine, a chemical sealant to prevent aluminum corrosion.

The RS005N robot conducts two vision checks at this point: one before the sealant application, and another one after application to ensure the sealant was properly applied.

From here, the turntable rotates so the RS010L can pick up the complete tooling package, which includes the nutplate and nutplate-locating tool. The RS010L robot scans three part features to ensure proper plane alignment for installation. It then grips the part at the defined feature.

While the RS010L robot holds the part, the RS080N robot enters the area and the two heads marry —  the RS080N robot’s rivet vacuum head places rivets inside the head of the RS010L robot, which installs the rivets into the part. Once the rivets have been installed, the robot heads separate.

The RS010L then safely releases the part and rotates to drop off the dirty tooling, and the RS080N rotates the EOAT to the correct position for rivet crimping, which completes the 39-second process.

When developing this system, SYSTEMATIX used Kawasaki’s hardware and software safety option, Cubic-S, to ensure the robot heads didn’t collide while installing the rivets. The integrator created zones for the robots to avoid, which prevented crashes with fencing or other equipment.

Aerospace Kawasaki case study

The RS010L and RS080N robots work together to install rivets. Source: Kawasaki

Results meet aerospace tolerances

The high-speed capabilities of these robots also helped the aerospace supplier increase throughput. The lightweight arm, along with high-output, high-revolution motors provide industry-leading acceleration and high-speed operation, said Kawasaki. The acceleration rate automatically adjusts to suit the payload and robot posture to reduce cycle times to 26 seconds, according to the Wixom, Mich.-based company.

When the rivets were shaved by hand, human operators had to apply the Alodine. Now, the aerospace supplier no longer has to take the time to apply the material, and the amount of sealant it must purchase is reduced.

The aerospace supplier has also reduced the number of operators from three to one. The robotic work cell creates fully completed parts, so no work-in-progress stations are needed. The manufacturer met its goals for reduced costs and increased production.

When asked where the aerospace manufacturer has seen the biggest improvement, P.J. cited part consistency without hesitation. After being in production for just over one year, the cell has achieved 97% consistency – a statistic that greatly affects the company’s bottom line.

“Now we’re increasing our production time [with the robot cell]. It’s operating 24 hours a day now, and we’re relying on it to get the production numbers we need,” said P.J. “The reality is we’re relying on the robotic cell — it’s the main part of the process now.”

The Robot Report has launched the Healthcare Robotics Engineering Forum, which will be on Dec. 9-10 in Santa Clara, Calif. The conference and expo focuses on improving the design, development and manufacture of next-generation healthcare robots. Learn more about the Healthcare Robotics Engineering Forum.

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