Ch. 0 - Fanuc Basics - Understanding Robotics,Tools & Software

#Robotics #FANUC #Industrial_Automation #Industrial_Robot

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Table of Contents:

1. Intro to 6-Axis Robotics

1.1 What is a 6-Axis Robot? 🎦

Video: https://youtu.be/UxO0xqvvGcM

In this section, we will discuss industrial robots and what they are; and the mechanical and electrical parts of a robot.

Robots are electro-mechanical devices that can be used for many tasks.

These tasks can be as simple as moving a box from one conveyor to another. Robots are excellent at doing very specific, repeatable tasks.

However, they can also be used for more complex tasks such as building automobiles on an assembly line.

a) Counting Robot Joints

The type of robot is defined by how many axes are used.

For each axis/joint, there is at least one servo motor that moves to support that part of the robot.

Each of these joints is made of servo motors with gears and belts to mechanically drive the robot.

Those servo motors use electricity to move the joints of a 6-axis robot.

Each servo is selected depending on the size of the robot.

The servo at the base of the robot, usually called joint 1, is the largest servo motor.
This motor must be able to turn the weight of the robot as well as the weight of the payload.

The smallest servo motor is usually called joint 6 and is usually at the end of the robot. Joint 6 only needs to move the payload in a specific motion, a motion much like moving your wrist.

Joints 2 to 5 can use one to two servos, depending on the payload. Most medium to small robots use only one servo per joint.

b) Robot's Characteristics

Assuming proper maintenance is being performed on the robot, some of its moves can be repeatable to a couple of tenths of a millimeter. The robot’s repeatability is one of the advantages of a 6-axis robot.

Some robots are small enough to place microchips on circuit boards,

while others can lift heavy objects like vehicles.

Each robot is sized to the desired application. A few factors in choosing a robot are:

• reach,
• payload
• speed.

c) Robot's Mechanical Brakes

Each 6-axis robot has mechanical brakes, a necessary part to prevent movement when the servos are not engaged.

Each robot has mechanical hard stops that prevent the robot from moving too far in on some axes.

d) Robot's Controller (Electrical Cabinet)

Another part of the 6-axis robot is the controller. A 6-axis robot controller is an electrical cabinet that houses all the main electrical components that are needed to drive the servo motors for each axis.

These cabinets have a few different main components.

– They have a disconnect switch that allows for Lockout/Tagout functions.

– The line voltages can vary but are typically within 208-600 volts AC.

– They have many printed circuit boards (PCBs). For exmaple, one of the PCBs controls the E-stop functions of the robot.

– Some 6-axis controllers have fuses to prevent the board from being damaged.

– There is also a servo amplifier in the 6-axis robot controller.
The servo amplifier is used to convert line voltage into a voltage that can be used by the servos.

– Each robot controller has some type of CPU, which is used to make movement calculations.

Note: Some 6-axis robot controllers are expandable to add auxiliary axes if a 7th axis is needed.

– These cabinets also can house IO modules for the interface of peripheral equipment. 

e) Robot's Control Panel (GUI)

Another part of the electrical of a 6-axis robot is the graphical user interface (GUI).

Some GUIs are electrically tied to the controller

while some use a computer instead.

The GUI tied to the controller, also known as Teach Pendant is a handheld screen with keys on it that are used when programming the robot.

When moving a 6-axis robot, there is a safety switch (known as Dead man's switch) that has three positions.

When the handheld screen’s safety switches are engaged in position 2, this will release the brakes and enable the servo controller to drive the motors.

There is also an E-stop button on the handheld GUI, which can force the robot to shut down if a human is dangerously close to a robot while it is running.

f) Robot's Encoder Backup Batteries and Internal Wiring

Another important part of a 6-axis robot’s electrical system is the servo encoder backup batteries.

These batteries will keep the servo encoder counts when the power is removed from the robot controller.

Note: These batteries should be periodically changed, or the encoders will need to be reset. Each manufacturer has a process to set the servo motor counts. Failure to change the batteries according to the manufacturer’s instructions can result in unexpected downtime.

Most 6-axis robots have cabling running through them.

These cables are for all servo motors and various sensors that are needed to run the robot. 
– Depending on the manufacturer, some of the inputs and outputs (IOs) are run internally.
– There are also external IO options that are used.

The IO of a robot depends on the application. The IO can drive actuators or see the status of sensors that are mounted on the robot.

1.2 Introduction to Fanuc Robot 🎦

Video: https://youtu.be/sAOfJgvAiD0

A Fanuc robot is a 6-axis robot that is manufactured by Fanuc Robotics.

This robot can come in many shapes and sizes.

a) Robot's color code

A Fanuc robot normally comes from the factory with a coat of yellow paint.

They can be other colors though...
A green Fanuc robot will denote that it is collaborative.

A collaborative robot is a type of robot that you can work closely with. That means, unlike a normal robot, there is no need to put safeguarding around this type of robot.

A silver Fanuc robot will usually denote a paint robot.

For example,

• Tesla, Inc.’s robots are painted red.
• Lucid Group, Inc.’s robots are painted gray.

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b) Fanuc robot controller cabinet and serial numbers

There are four main styles of cabinets for each controller:
 - A cabinet,
 - B cabinet,

• mate cabinet,
   - open-air cabinet.

• The B cabinet is easy to distinguish because it sits on the floor.
• The A cabinet usually sits on a stand or some sort of structure off of the ground.
• The mate cabinet is smaller than the A cabinet.
• The open-air cabinet is easily identified by the black color.

Each robot will have a designated F-number somewhere on the controller.

The F-number is the serial number for the robot’s mechanical unit and the controller. The F-number is critical when calling Fanuc for technical support or spare parts.

FANUC usually sends these components:

These contain software that can be used to revert the robot to factory defaults or to upgrade its features.

Note: It’s important to know where the media drive is at all times. A copy can be sent from Fanuc, but this usually takes time and adds the cost of shipping the media drive.

There are five models of a Fanuc robot controller cabinet. From oldest to newest they are:

• R-J3,
• R-J3iB,
• R-30iA, R30iB,
• R-30iB Plus.

Each controller has a different set of software that has added features on top of the previous version.

c) How to select the adequate Fanuc Robot based on its capabilities

A Fanuc robot has a moving structure which is called a mechanical unit.

There are many mechanical units and they vary depending on what the robot needs to do.

For small fast and light functions, an LR mate (mini robot) or SCARA robot might be your choice.

For heavy applications, such as moving things that are as heavy and large as a vehicle, an M-2000 will be a better choice.

Each unit is designated by a set of numbers and letters.

• The first number denotes which kind of robot it is.
   - Next is a letter that denotes the version of the mechanical unit.
   - The number after the forward-slash will denote the payload of a non-standard robot.
   - The last letter will describe the option of length, usually longer (L) or shorter (S) than the standard.

For example, an LR Mate 200iD/14L is a small robot with the D revision that has a 14 kg payload with a long reach.

Another example is an M-10iD/12 which is an M-10 robot with a 12 kg payload.

Each robot has a designated reach which is called out in millimeters.

Each robot also has a work envelope to show how far the robot can turn in reference to J1.

You can use the robot finder tool from Fanuc’s website to help you identify which robot should be used for your application.

d) How to Jog a Fanuc Robot (move manually)

To jog the robot you will need to understand how the “Deadman” switch works. 
The deadman switch is a three-position switch.

• When in the released or tightly gripped position the robot is in an unmovable condition.
• When the deadman switch is maintained but not squeezed the robot servos will release which enables jogging.

To jog press the COORDinate key until the display on the top right black square reads JOINT.
This tells the robot to only move one joint at a time.

While the Deadman switch is being pressed and one of the shift keys is also being pressed you can press a J1- or J1+ key to move the robot on J1.

Note: It’s important to note that each time the robot is jogged or moved, the deadman and shift key must be maintained because if either the shift key or deadman switch is released...

...then the process must be repeated.

e) Robot's Mastering (Servo Positions with Powered Encoders)

A robot’s mastering is a way for the robot to know where it is using the encoders on the servos.

The batteries keep the encoder counts stored on the robot.

If the batteries on the robot run dead and the controller loses power, the robot will lose its mastering.

Usually, the robot will warn you with a BZAL-XXX alarm.

In this case, the XXX represents a three-digit number code signifying what type of battery alarm.

With that being said, I would set up a maintenance schedule to periodically change the batteries just in case.

2. The Basics of Robotics

2.1 End of Arm Tool (EOAT): The Robot's Hand 🎦

Video: https://youtu.be/S61CEF8ZmqE

In this section, we will explain the uses of an End of Arm Tool (EOAT) mounted on a 6-axis robot.

We will also explain the applications of a 6-axis robot.

An end-of-arm tool has many other names such as:

• end effector,
• claw, gripper,
• robot tool,
• and others.

Simply put, the object which connects the robot physically to the work being done is an end-of-arm tool.

End-of-arm tools come in many shapes and sizes, depending on what work needs to be performed.

a) The Faceplate

The part of the robot that the end-of-arm tool connects to is called the faceplate. Each end-of-arm tool is mechanically connected to the faceplate with some sort of hardware.

It’s a good idea to understand how the end-of-arm tool is connected to the robot and regularly perform service on the robot to verify that the connection hardware is tight.

If for some reason the hardware comes loose, it could cause damage to equipment or even sometimes injure workers.

b) How EOATs are Powered

End-of-arm tools are powered in a few ways:

• Some use electricity to move servos that are a part of the end-of-arm tool.
  

Servo motors can be used to grip parts and move them from one place to another. When a servo motor is located on the end-of-arm tool, it is called an auxiliary axis.

• There are also pneumatic devices on a 6-axis end-of-arm tool, which can grip a part using compressed air.

Compressed air is commonly used because it’s relatively inexpensive to purchase and operate.

• However, hydraulics can be used depending on how much pressure is needed to close the part.  
  

c) How to place the EOAT Wires in a Robot

Whether a 6-axis robot uses electricity, pneumatics, or hydraulics, it is important to route the cables in such a way that when the robot moves it doesn’t smash, pull, or break the wires and lines that go to the end-of-arm tool.

To safeguard the wires and lines some robots have mounting places placed by the manufacturer to route cables.

Some even have hollow spots inside the robot to allow for cables to be run through it.

d) Detachable EOATs (examples)

Most end-of-arm tools are fixed, meaning they are attached with hardware and don’t come off except for maintenance or service.

However, there are also changeable end-of-arm tools, which means that depending on the work that needs to be done the end-of-arm tools can be swapped.

They can be even swapped during operation with a stand or mechanism.

Or we could have 2 robots doing each task. We have many options with robotics.

e) Types of EOATs and its Applications

We will now explain the different types of end-of-arm tools with their associated applications:

1. Pick and place Robots, that pick up and place, use a way to grab onto the object or some sort of vacuum device to hold on to the object. 
   

• "Claw" - Pick and place end-of-arm tools can look like a claw that opens and closes. Pick and place robots are used for a variety of applications but they are always moving an object from one place to another.

• "Foam pad" - Pick and place end-of-arm tools can also look like a big foam pad. When the vacuum is engaged, the object is temporarily stuck on the end-of-arm tool until the robot releases the object. These foam end-of-arm tools are used in palletizing applications.

2. Spray gun: These tools allow the robot to coat objects in paint. An example of a spray application is a vehicle that is being sprayed by a robot.

3. Welding gun: This end-of-arm tool allows the robot to weld metal together. The welding gun, like paint robots, can be controlled by discrete I/O so that the weld length can be precisely controlled.

4. Vision inspection camera: This end-of-arm tool can hold a vision inspection camera. This camera is used for quality assurance for parts with critical specifications. Robots can use pick and place and camera inspections together to track the movement of a part on a conveyor.

2.2 What is 6-Axis Simulation Software?🎦

Video: https://youtu.be/LNnd4gd8kGQ

In this section, you will learn what 6-axis simulation software is, what it is used for, and the advantages and disadvantages of using it.

Some robot manufacturers have software to simulate running a 6-axis robot to help with the design.

a) Simulation GUI

6-axis robot simulation tools are usually hosted on a computer that simulates a real robot.

6-axis robot simulation software makes a virtual representation of the physical robot. The GUI software shows and environment will help you visualize the 6-axis robotic cell.

The ability to see the robot in its virtual environment can be helpful to robot designers, programmers, and engineers.

b) Export Robot Code with the GUI

Some 6-axis simulation software will even replicate or copy actual files from the real robot.

c) Picking the correct Robot using Simulation Software

One of the many things 6-axis robotic simulation software can be used for is specification purposes.

The software helps you pick which robot is right for the job.

Using the simulation software you can select a robot virtually and see if it will fit and maneuver well with any equipment, tools, or obstacles that are part of the job.

d) Robot Placement Considerations and Managing Obstacles with Simulation

When placing a robot, you may or may not control its location. If you do, choose a spot away from obstacles to avoid issues with a 6-axis robot, like slowing down or accidental collisions.

If obstacles can't be avoided, use 6-axis simulation software to design the robot’s movements.

For example, in a cell with two pick and two-place locations, a direct path may cause the robot to hit obstacles like an I-beam. You can pre-program movements to avoid obstacles. Simulation helps anticipate these and adjust the programming accordingly.

e) Selecting the Right Robot and Using the Five-Sixths Rule for the Cycle Times

Simulation also helps select the right robot, considering its reach and speed. After designing the robot's path, you can measure the cycle time.

Some software lets you time the cycle and apply the five-sixths rule, ensuring the robot runs slightly below its maximum speed for safety.

The five-sixths rule helps determine if the selected robot meets cycle time or if a different model is needed, avoiding costly purchases.

f) Advantages of CAD File Import

You can also import CAD files into the simulation,

to replicate machines interacting with the robot.
This saves time by not having to program machine interactions manually.

g) Pros and Cons of Robot Simulation

Next, I’ll cover the benefits of 6-axis simulation software.

• Simulation helps visualize and troubleshoot designs without a physical robot, making it easier to address issues remotely and at a lower cost.

• It’s useful for recreating problems and programming projects when no physical robot is available. However, be cautious: inaccuracies in dimensions can lead to incorrect assumptions, such as slower robot performance.

Now the disadvantages:

• Sometimes, simulating every detail takes too much time. Use the software efficiently—don’t overcomplicate simple cells with too much simulation.

Balance time spent on simulation with practice. It's a valuable tool for saving costs and troubleshooting without the need for a physical robot.

Simulating helps you learn the robot’s speed and limits, saving time during design and troubleshooting.

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