The Complete Guide to Robot Calibration

Robot calibration ensures machinery is functioning correctly and performing at peak capacity. All robots require some form of calibration, from axes to sensors and cameras. This process may seem intimidating the first time around. Luckily, it is straightforward and easy to get started with the right approach. 

Here are the basics of robot calibration and tips for a successful process. 

Why Is Calibration Crucial?

Robot calibration is crucial for proper performance. Robots can be extremely precise and efficient, but only if calibrated properly. This tunes up its sensors and parts so it can be as accurate as possible. It’s similar to how people use glasses to improve their vision. Robots need to be regularly maintained, even if their components or environment haven’t changed. 

A prime example of the importance of robot calibration is industrial machinery. Imagine a robot that is mass producing a certain car part. If it’s not calibrated correctly, it could create hundreds or even thousands of defective components. Accuracy is critical for successful robotic automation in any industrial application.

Additionally, a poorly calibrated robot can suffer maintenance issues over time. If it isn’t operating the way it is designed, there is a much greater chance of accidents or breakdowns. Regular calibration is key to safety, maintenance and performance. 

What Needs Calibrated?

Usually, a robot’s manual will include details on specific parts that need to be calibrated regularly. In general, though, things like sensors, cameras, tooling, joints and axes require calibration. Different machines and components will need to be calibrated more frequently than others. 

Sensors need regular calibration to account for environmental changes. They may also simply lose accuracy over time due to everyday use. Temperature and weight sensors may need “zeroed” before measuring something, which would require more frequent calibration. 

Cameras have the most flexible calibration. There are many ways to use a robot’s cameras, depending on specific circumstances. It could be calibrated to adjust for light, contrast, color or other settings. Cameras will likely need to be calibrated more often than most other parts. 

Components like motors, axes, tooling and joints may be the most hands-on parts to calibrate. However, these mechanical parts won't need to be checked as often as others. This may be as easy as switching on a preprogrammed process, depending on the specific model of robot. Others may require tools and a bit of manual calibration, though. Before diving into any mechanical robot calibration, make sure to carefully study the manual and know who to contact if there are any issues. 

Robot Calibration Methods

Robot calibration methods will vary slightly from model to model. However, one of two common approaches is generally used. Most robots can be calibrated either by hand 3D laser tracking system. The main difference between the two methods is user input. 

Robot calibration by hand is all manual. The machine is moved manually to a certain position or orientation, the “checkpoint” for calibration. By contrast, 3D laser tracking is fully automated. The robot will use preprogrammed instructions to move to precise calibration positions and orientations. 

Most robots can use either calibration method. However, laser tracking can be expensive. If a robot just needs basic offline calibration, it may be best to opt for manual instead. Laser tracking is only necessary when exact, precise performance is required. Of course, those who can afford laser tracking for all their needs get more reliable accuracy. 

The Robot Calibration Process

The robot calibration process follows the same general outline across most methods and models. There are four main steps: choosing a standard, testing, correction and results. This process measures performance before calibration and corrects any inaccuracies. 

Choosing a standard is the process of determining what you will use to measure performance. The one used depends on what component of the robot is being calibrated. Regardless of the choice, the most important part of this step is verifying that it lines up with national or international measurement standards. 

After selecting and verifying the standard used for the robot calibration, it’s time to test the robot or component’s current performance. This step will reveal how much calibration is needed and in what direction. Maybe a camera is set for too much contrast or a scale is not zeroed correctly. Components are tested by recording a sample of operational performance. Make sure to write down or keep track of the pre-test results to compare in post-calibration testing. 

The core of the robot calibration process is correcting performance based on the pre-test results. This step will vary among robots and situations. Some circumstances may call for manual calibration, while 3D laser tracking will be necessary for others. Some robots may come with a program already installed, while individual tools, parts and even whole robots may need technicians to start from scratch. Usually, the best course of action is to use any instruction provided and go from there. 

After correcting performance, the last step in the robot calibration process is post-testing and reporting results. This verifies everything was calibrated correctly. Technicians may need to go through correction and post-testing multiple times to fine-tune things if a robot needs highly precise calibration. 

Tips for Proper Calibration

Calibration is vital for anyone who wants to be a robot technician, engineer or manufacturing professional. The key ingredient is patience. It may take some time to get the robot calibrated just right, but the important thing is paying attention to the details and not rushing. A few best practices and tips may help streamline the process.

Generally, older robots and equipment will need calibration more often. However, no matter the age of the machine, it is always a good idea to follow the manufacturer’s calibration instructions. This may mean using a manual instead of an automated system. However, it is better to stick to the recommended method than risk accidentally damaging the robot. Always calibrate in a clean area with plenty of space and no potential hazards. 

Make sure the robot is never overtaxed to reduce the need for frequent calibration. Only trained technicians should be operating it. Monitor its performance when in use for signs that it may need calibration or maintenance. Careful, attentive service will extend the life of robotic equipment and avoid costly breakdowns. 

Robot Calibration Benefits Everyone

Taking the time to correctly calibrate robots results in better performance and a safer workspace. A properly calibrated robot will work better and operate with maximum accuracy and precision. Regular calibration also ensures that robotic equipment stays in good working order. It’s usually a quick, straightforward process that pays off in the long run and boosts value and performance.