AUTOMATION WIKI FOR SURFACE TREATMENT
We have created a short automation wiki to explain the most common automation and robotic principles within surface treatment. At Clemco Denmark we perform automation projects for a large diversity of companies, but all our customers are focusing on surface treatment for protective coating or surface preparation of larger steel structures.
This means that we have developed a large pedigree of automation projects in the steel industry.
The wiki below will give you a short and helpful introduction to the most common terms and principles in automation of processes in the surface treatment industry.
ATEX (shown in picture)
ATEX is an acronym for "ATmosphere EXplosible". At the same time, ATEX is the shortened name of the European Directive 2014/34/EC concerning the placing on the market of explosion-proof electrical and mechanical equipment. Most painting robots and auxiliary equipment will require an ATEX marking when used in an explosive atmosphere.
CELL (shown in picture)
The robot cell is the fenced area where the robot can operate. The cell is a defined space and is normally fenced to avoid people from entering the cell while the robot is active. A paint booth with door controls is a common defined cell for robotic spray painting.
The controller is the hardware/software that control the robotic servo motor. The controller will receive its input from the teach pendant.
A robot dedicated for dispensing of glues or sealants on a specific work piece area for gluing of work pieces.
END OF ARM TOOL (EOAT)
A typical used description for the tool itself, which is mounted outermost on the robot's arm. For surface coating this can be a spray gun (spray tip) or a metallizing gun head.
EXTERNAL AXIS (shown in picture)
An external axis is normally referring to an extra axis required for the robot to cover the entire length of workpiece with a size exceeding the working area (envelope) of the robot. Clemco Denmark have many examples of external axis’s required when a robot has to be transported along a large steel structure for surface coating or surface preparation. The robot is driven by a servo motor (external drive) on the external axis. The servo motor’s parameters can be read in the robot controller display for easy programming of the robot’s position.
FLEXPENDANT (shown in picture)
The FlexPendant is ABB’s teach pendant or a hand held operator unit used to perform many of the tasks involved when operating a robot such as running programs, jogging the robot arm with the joy stick or modifying robotic programs. The FlexPaint pendant can be Ex certified for operations in explosive atmospheres. This means the operator can operate the pendant inside a spray booth for making in-situ adjustments when the robot is performing spray painting.
The manipulator is a robotic arm with one or more axis that can perform a certain robotic process.
The off line simulation process is widely used for simulating a certain robotic program in a software system such as RobotStudio. It is possible to create a robotic program and export the program to a robot for easier programming. In surface treatment this process is very efficient, but in all cases manual programming will be required for optimization of spraying patterns. However the off line simulation can quickly determine if the spraying booth is too small for the robotic movement required for painting the workpiece.
Overlaps or overlapping is the spray pattern used in both metallizing and spray painting for coating a workpiece. The spray pattern will use overlaps for building up the correct layer thickness of the coating material. In most cases a spray tip or nozzle will have a certain spray pattern with the highest amount of material to be dispersed close to the center and less material in the periphery of the spray pattern. This is why overlaps must be closely controlled to ensure the correct layer thickness in a spray process.
A robot that can place a work piece on a pallet. Typically used for workpieces that are unloaded from a conveyor and ready for next process. Not very used automation project in the surface treatment industry.
Picking is the principle of a robotic arm equipped with a hand tool that can grab a work piece and orientate the workpiece correctly for the next manufacturing process. Palletizing robots are often limited to 4 axes in order to achieve very high speeds in the work flow.
ROBOTSTUDIO ABB (shown in picture)
The ABB RobotStudio is ABB's simulation and offline programming software, RobotStudio, allows robot programming to be done on a PC in the office without interfering with production flows. The program made in RobotStudio can be exported to the robot and used as program. This approach with offline programming is very common for testing a robot’s working envelope and to determine the placement of the robot in relation to the workpiece.
SERVO SYSTEM (shown in picture)
A servo system is comprised of four components: a motor, a drive, a controller, and a sensor (encoder). The controller and drive correlates to determine what the motor needs to do (the controller) and send the necessary electrical energy to the motor to make it happen (the drive). Servo systems can be integrated with robots for moving the robot in one or more additional axis. This is very common when performing surface treats of large steel structures.
The singularity issue can be described by an example if you imagine the robot is painting a line using a spray gun. To paint a perfect line, the robot needs to move at a total constant speed. If the robot changes speed you will obtain changes in the layer thickness. Obviously, it's important that the robot moves along the line at a constant speed. Robots are very precise and can handle this spray simple spray pattern without a problem. However, if there are any kinematic singularities in the line, the paint job could be ruined. Singularities are caused by the inverse kinematics of the robot. When placed at a singularity, there may be an infinite number of ways for the kinematics to achieve the same tip position of the robot. If the optimal solution is not chosen, assuming there is one, the robot joints could be commanded to move in an impossible way.
Is the handheld programming unit used for programming the robot. This is also referred to as "Programming Pendant". The teach pendant is basically the hand held control panel which can be used to control a robot remotely.
TOOL CENTER POINT (TCP) (shown in picture)
A tool center point (TCP) is the exact point in an x,y,z coordinate system of a robotic tool. The tool center point (TCP) is the point in relation to which all robot positionings is defined. The best example is a welding arc, where the tool center point is the welding spot.
A turn-key system is a project delivered to the client by one supplier. And the project is up and running on a specific date at the agreed price. This ensures that the client only have one supplier to contract with even though the system might be built up by several sub suppliers.
A workpiece is the acronym for the steel element that is being handled or processed by the robot or an automation process. The workpiece can be placed on a jig that fixates the position of the workpiece for the robot to detect the workpieces’ position.