The demand for new automation solutions in industry is high and nowhere is this truer than in the packaging industry. Traditionally, picking and packing are considered labour-intensive. Often, assorted products are packed at high speed into boxes, trays or blisters. The high pace of the process, using manual labour, can result in production bottlenecks affecting throughput. Employee can also develop health problems as a result of the highly repetitive nature of the work. Automation is an attractive alternative and picking and packing robotic solutions represent one of the fastest-growing markets in the automation industry.

The packaging industry has for decades used manual labour for picking and packing products into boxes, trays and blisters. A typical application is packing mixed chocolate pralines into blisters, a repetitive task that is performed at very high speed. This type of work is tedious and generally poorly paid, which makes it increasingly difficult to find and retain labour. Additionally, growing concerns about food safety have encouraged the industry to seek alternative ways to pick and pack food, so that human contact is minimised. For these reasons, the industry has shown a great deal of interest in automation.

In the late 1990s, robots were generally designed in a serial manner. One part of the robot was attached to another in a sequential fashion and each part carried the weight of its own motor. This resulted in robots with heavy arms and slow product handling speeds, unable to compete with labourers capable of accomplishing 60–100 cycles a minute. To resolve the issues and tap the growing potential of ripening food packaging markets worldwide, ABB developed an innovative FlexPicker, IRB 340 robot series. The FlexPicker, a delta robot uniquely designed for the picking industry, could pick and pack small lightweight objects, such as chocolates.



ABB FlexPicker IRB 340
The design principle of the earlier model of ABB FlexPicker was quite simple but controlling it was more difficult. High-speed movement was achieved relatively easily with small motors. Another challenge was to move the robot at such speeds without causing jerky movements or destroying the manipulator. The company was well placed to overcome such a challenge, since its advanced motion controller was superior to its competitors’ for standard robots and this technology was capitalised upon during the development of the picker. The result was the highly successful IRB 340, which can pick and place products quicker and more gently than any other robot.

Developing a market
The packaging industry is huge and fragmented with over 25,000 food plants globally and large multinational food companies that hold less than 5 per cent of the market share. The companies selling packaging solutions are also numerous and fragmented, which presents an obvious obstacle to ABB, when seeking efficient sales channels to the customer.

From the outset, the company’s strategy was to sell products rather than complete solutions or installations. It was perceived that the most effective strategy would be to sell products to existing system integrators and machine builders who were already active in the packaging industry. The objective was to create a demand for ABB’s robot-based automation within a market that already had well- established alternative solutions. The challenge was not only to sell ABB robots to system integrators, but also to create market awareness to generate demand from the end customer. This endeavour started to yield returns in 2003, five years after the initiative was launched and now grows annually by 30–40 per cent.

Design improvements
Ten years after the introduction of IRB 340, ABB launched the IRB 360, a secondgeneration high-speed picking robot, in 2008. The new model satisfied this demand and even provided solutions for new applications, creating new markets, which in turn have boosted sales. An important factor influencing the timing of the launch was the expiry of the original patent, which prevented competitors using parallel arms in their robots. In this highly competitive industry it seemed obvious that other companies would immediately start building delta robots. ABB’s competitive advantage would now depend on its long experience of building these robots, its wellestablished reputation for quality and its large market share reflected by its large sales volume. To remain the market leader in this technology, ABB’s strategy was to improve upon the advantages of the old FlexPicker, so that the new FlexPicker could carry higher payloads and target new branches of the packing industry.

Benefits
Improvements in the design and strength of components created a more durable and robust robot that required minimal maintenance to achieve maximum operating time. Additional design features have made the new-generation delta robots more versatile, a smaller version taking up less space on the factory floor and a new version for the food industry that allows thorough cleaning using standard industrial methods. A few benefits of the IRB robot series are discussed below.

Advanced motion control
One of the most important features of the delta robot is its advanced motion control, which is fundamental to the overall performance of the machine. It is easy to build a delta design robot and incorporate a high torque motor to move it very quickly. The challenge is to make it fast and accurate, while maintaining a long lifespan. High performance comes from advanced motion control. The control loop in the ABB robot controller plans the movement of the manipulator, taking account of its dynamic behaviour to reduce mechanical stress. The benefits of the robot’s advanced motion control were illustrated when the company got an order by a Swiss pretzel producing company. ABB beat the competition, winning the order because the ABB delta robot could pick and place the pretzels at high speed, while reducing the scrap rate from 12 to 4 per cent. The ABB motion control is suitably named QuickMove and TrueMove. The IRB 360 has been developed using the newly released second-generation QuickMove and TrueMove motion controller, which has allowed significant cycle-time improvements. On average, the IRB 360 is 20 per cent faster than the IRB 340, with the best results for payloads of between 1.5 and 3 kg.

Sometimes frozen products, for example, can be frozen together and then separated during movement, or products can be repositioned during a sudden conveyor belt shutdown. Such product relocation can cause problems for a robot, resulting in unexpected collisions. With the FlexPicker, the lightweight arm system detaches during a heavy collision. The arm system is held in place by a spring unit that protects the arm from damage during a mechanical impact, even when fully accelerating. This safety feature protects the robot, but customer feedback suggested that a robot that stops moving when the arm system falls off would further protect the product and the conveyor. The new QuickMove and TrueMove motion controller can now detect a malfunctioning arm system and automatically stop the robot. This feature is unique to ABB delta robots and will support ABB’s leading position in high-speed picking.

Enhanced robustness
A high-speed picking robot can typically make 130 pick-and-place operations a minute. In a production line made up of eight robots, this equates to over one million cycles a day, and over 200 million cycles a year. Even with a low failure rate of one in a million, the probability of a malfunction becomes a daily event. Such a failure rate is unacceptable and can be reduced only by making the robots extremely robust. Universal joints, theta axes and fixation screws are critical elements that had to be improved. In IRB 360, the components have been made stronger so that they last longer and require less maintenance. Improved design features of the machine ensure that parts can be replaced easily, even by relatively unskilled technicians. Such features include enlarged screw dimensions and guiding sections so that service and repairs can be made easily and cannot be made incorrectly.

A simple example of altered design to improve ease of use is the relocation of the brake release button from the central, relatively inaccessible part of the robot to the outside. This makes it easier for the operator to reach the button when working with the robot. Another improvement is that the robot no longer requires re-lubrication after cleaning, since new low-friction plasticbearings are now used.

Saving floor space
Floor space is always at a premium in industry and the food industry is no exception. Increasing productivity within a given area is one of the frequent demands made of robots. The standard ABB robot controller is, however, too large for most food and pharmaceutical industry applications, which is why a modified controller was developed several years ago. A smaller footprint was achieved by packing the components more densely and increasing the unit’s height. This new controller rapidly gained popularity among picking customers, saving crucial floor space and reducing costs, since the new controller was housed within the customers’ existing control cabinets. When developing a new robot, reducing the size of the footprint is a neutral requirement for the development team; however, keeping the number of parts to a minimum is, for cost reasons, a high priority.

The upper arms of the original IRB 340 covered a lot of floor space when pointing straight out. By shortening the upper arms and decreasing the work envelope, the new IRB 360 requires less floor space, even without changing the base box (a floor space reduction of up to 30 per cent). The width of a FlexPicker cell was decreased from 965 mm to 810 mm and its length reduced from 980 mm to 820 mm. Even greater space savings can be imagined, when the increased cycle speed of the IRB 360 is considered. Higher performance means that seven new IRB 360 robots can replace eight old IRB 340 robots, providing total floor-space savings of as much as 40 per cent.

Scope in Food Industry
The first-generation IRB 340 was used in the food industry and was available with a stainless base-box option. Many other components, however, were made from anodised aluminium, which is washable, but was chosen primarily because it is lightweight. Anodised aluminium cannot withstand scratches or the aggressive detergents used in the food industry. For this reason, the IRB 340 cannot be cleaned using the same methods used for all other foodindustry equipment—it requires a more delicate cleaning treatment. The newgeneration IRB 360 has an improved sanitation design, which although heavier, can be more easily cleaned. It has all stainless metal components, including the theta axis, delta plate and arm end caps, as well as a watertight casing (IP 69K), which allows it to be cleaned with hot, high-pressure water at close range. This means that no special time-consuming arrangements need be made to clean the robot. It can be treated just like any other equipment in the plant.

From picking to packing
The FlexPicker, IRB 340 delta robot was first developed for picking and packing small lightweight objects, which are easily relocated, using a simple vacuum cup pickup tool. Once the IRB 340 was released to the market, a large number of different product picking and packing applications were attempted. A popular application today is unloading a flow wrapper and packing products into boxes. This is typically done by grabbing eight to 12 pieces at a time using a large multi-vacuum gripper. Of course such increased payloads, to some extent, slow down the FlexPicker, but worse still, can impact the inertia of the tool. The larger the offset from the centre point of the robot tool, the lower the FlexPicker’s performance. This can make the robot’s operations uneconomical, especially if the operator reconfigures the system incorrectly. If the robot performs outside its design limits, its lifespan and maintenance costs may be affected.

The goal while developing the IRB 360 was to allow an increased payload by increasing the torque on the fourth (theta) axis in the middle so that the robot would be more versatile, and increasing its scope for new applications without reducing the lifespan of the robot. Case packing with a FlexPicker is a very common application, yet by expanding the payload from 2 to 3 kg, the number of packing applications was dramatically increased. The IRB 360 robot can pick up heavier products, handling sausage packs of 2 kg with a 1 kg gripper, as compared to the IRB 340 robot, which can only pick up 1.3 kg sausage packs with a 0.7 kg gripper. This improved performance presents the possibility of doubling production throughput.

Earlier discussions about payload increases focused on redesigning the arm system. By separating the parallel arm, the new robot could be made stronger, but this would also affect its weight. A further drawback would be an increase in the number of required components, since different arm systems would be needed for different payloads. Again these problems were solved by the new motion controller. The improvements made in robot movement control actually made it possible to handle 3 kg payloads using the same arm system as before with even shorter cycle times. Smoother robot movement and a greater understanding of the robot’s limitations have given the IRB 360 a 30-per cent performance improvement with a 2-kg payload as compared with the IRB 340 model.

Sales Launch
The sale of the IRB 360 started in April 2008, and phased out the IRB 340 completely by October 2008. The smooth transition from IRB 340 to the IRB 360 was possible because the machines are very similar, except that the IRB 360 can outperform the IRB 340 in all aspects. Future sales are predicted to grow thanks to an expanding picking market, despite the recent entry of new competitors to this market. A promising future for the stainless FlexPicker version is also predicted in the meat industry. In fact, in all parts of the world, there is great interest from industries with large picking lines to install reliable robots within a limited amount of floor space. The market is ready and there is a demand for automation with high-speed delta robots.

The author is Product Manager, ABB Robotics, Västerås, Sweden