lipiec 20, 2022
Industrial robots come in many different forms and can be used for a variety of tasks. At one end of the spectrum are large machines designed for heavy lifting and fast processes. To ensure safety, access to the space where they are used must be restricted and tightly controlled. At the other end of the spectrum are collaborative robots – or so-called cobots. They are generally the size of a workbench and work alongside workers, usually taking over repetitive, highly involved tasks and those that must be completed at strictly defined intervals.
In between these two extremes are robots designed to handle loads ranging from a few grams to around 50 kg. They allow the automation of many processes, part of which involves repeatedly picking up an object, carrying it and placing it at a specific point. Due to the specific nature of these tasks, speed, accuracy and repeatability of movement are of key importance to users in this area, as well as the ability to use where sterility must be maintained. SCARA (Selective Compliance Assembly Robot Arm) robots are widely used in this area.
SCARA robots are a technology that has been improved over the years and is affordable. This type can be installed individually or in groups with other SCARA robots or with different types of robots such as Cartesian, single-axis and multi-axis robots. What’s more, they work perfectly with YAMAHA’s LCMR200 linear conveyor modules for flexible component handling. Unlike conventional belt and roller conveyors, these modules are programmed and controlled in the same way as other robots, creating a fully integrated and coordinated robotic assembly cell. A closer look at the latest generations of SCARA robots shows that these machines are constantly being improved to meet the demands of modern manufacturing.
The advantage of SCARA robotsÂ
At first glance, it may appear that today’s SCARA robots differ little from earlier generations. As with their predecessors, the defining feature is an articulated, biaxial arm that operates in a single plane. While science fiction and early cobots such as Baxter predicted that future robots would have more humanoid forms, SCARA-type robots have proven consistently excellent at mimicking the movements of the human arm. It can extend and retract and rotate around the axes of both the ‘arm’ and the ‘elbow’, independently and simultaneously. It can move to any point within the area defined by the maximum extension of both segments, and can also reach inside enclosures. The YAMAHA YK-XE family of affordable, high-performance SCARA robots is designed for tasks requiring the handling of parts weighing between 4 kg and 10 kg.
Thanks to this flexibility, SCARA robots can perform a wide range of operations, such as moving objects from one place to another, picking and placing or positioning components in assemblies, and performing processes such as screw driving, dispensing and engraving. Above and beyond this large range of functionality, the high accuracy and precision of this design speaks for the use of SCARA-type robots. This enables them to carry out demanding industrial tasks with a high degree of repeatability.  Its range includes models with high repeatability even reaching a range of ±0.01 mm in the X, Y and Z axes and ±0.01° in rotary motion. The exception is the YK710XE model with the longest arm length in the family, reaching 710 mm, characterised by a repeatability of ±0.02 mm in the X and Y axes.
Thanks to this flexibility, SCARA robots can perform a wide range of operations, such as moving objects from one place to another, picking and placing or positioning components in assemblies, and performing processes such as screw driving, dispensing and engraving. Above and beyond this large range of functionality, the high accuracy and precision of this design speaks for the use of SCARA-type robots. This enables them to carry out demanding industrial tasks with a high degree of repeatability.
The YAMAHA YK-XE family of affordable, high-performance SCARA robots is designed for tasks requiring the handling of parts weighing between 4 kg and 10 kg. Its range includes models with high repeatability even reaching a range of ±0.01 mm in the X, Y and Z axes and ±0.01° in rotary motion. The exception is the YK710XE model with the longest arm length in the family, reaching 710 mm, characterised by a repeatability of ±0.02 mm in the X and Y axes.
The accuracy and precision of these robots allows them to be used, for example, for the tasks of positioning small mechanical components such as small springs or washers, or for picking and placing surface-mounted electronic components. Their payload capacity also allows them to be used for handling or assembling heavier components such as automotive parts.
These robots therefore allow mundane and repetitive tasks to be transformed into processes that can help companies choosing to invest to stand out from the competition. This is because the machines not only work faster, but also for longer and with fewer errors than humans, so that a person’s skills – extraordinary dexterity, problem-solving, creativity – can be used to greater benefit elsewhere.
Motion control
The latest generation of Yamaha YK-XE SCARA robots has been designed with a new, lighter head assembly and improved motion control. This provides greater acceleration and reduced vibration. The control strategies developed by YAMAHA for SCARA robots automatically optimise linear and angular acceleration, taking into account arm orientation and load inertia, to reduce maximum torque, prevent excessive vibration and improve controllability. This not only helps to minimise cycle time, but also to reduce mechanical stress, resulting in greater reliability.
Robot vision system
With precision motion control, SCARA robots increase productivity in many industrial processes. The integration of a vision system further extends the machine’s range of applications, enabling functions such as conveyor tracking, position detection and position compensation to increase process accuracy. This is particularly important for tasks such as applying glue or sealant to the edges of an assembly or applying labels to parts that may be irregularly distributed on the substrate.
System wizyjny RCXiVY2+ firmy YAMAHA składa się z karty wizyjnej, karty oświetleniowej oraz karty śledzącej, które są zainstalowane w wieloosiowym kontrolerze robota serii RCX3. W ten sposób w programie robota połączono zarządzanie sterowaniem robotem, przetwarzanie obrazu, sterowanie oświetleniem oraz przetwarzanie danych potrzebnych do śledzenia przenośnika, co znacznie skraca czas konfiguracji sprzętu.
The RCXiVY2+ system features a new cluster detection function that can recognise items two to ten times faster than the edge detection technique used previously. This enables robots to detect, retrieve and quickly count multiple items of indeterminate shape and size, such as groceries and clothing.
Programming software
To facilitate the configuration of a single robot or assembly nest, the supplier offers feature-rich software tools that make programming and configuring the robot easier and faster. YAMAHA’s RCX-Studio 2020 environment provides tools to help manage robots from configuration to maintenance and wizards to automatically generate sample applications. These ready-to-use templates help to easily program common activities such as pick and place, palletising and conveyor tracking including vision-enabled processes without having to write commands.
Tools such as an emulator, cycle time calculator and real-time tracking are also available, and another new feature is the 3D simulator, which allows for checking, debugging and optimising programmes offline. Tools available in the simulator include a trajectory display, which allows operators to evaluate the robot’s movements, and tests to help avoid collisions with other robots or peripherals. The software allows simulation of the movements of four robots and inspection from multiple viewpoints. Using the simulator, the robots’ positions, sequence of actions and optimal speed settings can be quickly determined before the real work begins. This reduces the number of actual trials and errors, especially when configuring a multi-piece assembly cell, and enables production to start sooner.
Ready-to-use solutions
 The automation of processes such as dosing or coating can be further facilitated by the use of off-the-shelf solutions. YAMAHA SCARA were used in the REECO Robot series awarded with the TERAZ POLSKA emblem. This includes Soldering Robots, Twisting Robots and, of particular interest from the point of view of this study, Dispensing and Coating Robots.
Awarded the TERAZ POLSKA emblem in 2020, REECO robots have been developed to operate in production and production-service facilities. For this reason, they feature solutions that enable both offline and in-line operation, including, depending on the model, two transport options: edge and rotary table. The first option allows several robots to be freely combined or linked together with other types of equipment, thus enabling many tasks and more complex processes to be carried out. The second option, in the form of a rotary table, which is new in the REECO offer, facilitates and accelerates the manual insertion of a workpiece (e.g. PCB) into the work area.
What is particularly important is that, in addition to using YAMAHA components in them, all of the units in this series are based on the REECO Robotic System. Thanks to this full compatibility, the head can be changed in these devices. For example, the Paint Robot can, if required, be functionally changed into a soldering robot, a twisting robot, a dispensing robot or any other – in a customised application. This gives users the ability to respond to changing market pressures or production needs and to quickly reorganise line elements without having to purchase a new machine.
