What is robot calibration?

So, what is robot calibration, exactly?

Robot calibration is the process of making sure your robot's movements match what you programmed it to do — as simple as that!

Basically, sensors and software translate your commands into the precise movements of joints and limbs. Over time, a robot's parts can shift out of alignment, causing its movements to become inaccurate. That’s why it’s important to keep your bot well-calibrated. 

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The importance of calibration for industrial robots

Industrial robots have plenty of complex moving parts, so you need to keep them calibrated to ensure proper functioning. 

Without calibration, your bots might: 

• Miss their mark: Imagine a basketball player who can't get the ball in the hoop. That's what an uncalibrated robot is like. It might not be able to reach the right spot with the same accuracy, leading to mistakes and wasted materials.
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• Slow down your production: Just like a car that needs a tune-up, an uncalibrated robot can start moving slower than it should. This can cause bottlenecks in your production line and cost you valuable time and money.
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• Throw a tantrum: Uncalibrated robots are more likely to experience errors and malfunctions. This means more downtime for repairs, and nobody wants that. Plus, it could potentially be unsafe.

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How to perform robot calibration: A step-by-step-guide

After you make sure your bot is powered on, you’ll need to: 

1. Open the robot software and select “calibrate” from the menu.
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2. Place the robot in its home position, typically flat on a table with arms at its sides. Ensure any attachments like grippers are removed. Click “start” in the software to begin calibration.
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3. The robot will now rotate each joint to determine its full range of motion. It may make some whirring and clicking sounds as it moves — don’t worry, this is normal. Once it finds each joint’s limits, it will return to its home position.
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4. Teach the robot about proper orientation. Click “set home” in the software. The robot now knows this is its default starting position.
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5. Finally, you’ll jog the robot to a few points in its workspace. Use the control pad in the software to slowly move one joint at a time. Click “add point” at each location. Provide at least 3 to 5 points total.
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6. Click “end” to complete the calibration. Your robot is now ready to operate! Perform calibration when first using your robot, if its behavior seems off, or if its environment changes. 

Of course, your robot model may need a slightly different process, but this step-by-step guide will work with most industrial robots out there.

Tools and technologies used in robot calibration

To achieve pinpoint accuracy, robots need a bit of fine-tuning through calibration. 

Here's a breakdown of the tools and techniques involved:

• Laser trackers: These high-tech tools precisely measure a robot's position and movement by firing laser beams at its joints and links, detecting any positional errors.
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• Coordinate measuring machines (CMMs): These use touch probes to physically measure the robot's dimensions, guaranteeing a perfect fit for its tasks.
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• Encoders: Attached to the robot's joints, these devices act as its internal odometer, counting rotations to calculate angles and positions.
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• Accelerometers and gyroscopes: This dynamic duo helps the robot maintain its balance and orientation, with accelerometers detecting changes in velocity and gyroscopes measuring angular velocity.
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• Calibration software: This software is the brains behind the operation. The software gets data from all the sensors and instruments, creating a precise model of the robot. By comparing this model to the robot's actual performance, it tags and corrects any inconsistencies, resulting in improved accuracy and repeatability.
  
  Some even provide visual reports to illustrate the robot's calibration status.

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Benefits of regular robot calibration

There’s a lot to love about regular robot calibration. 

Let’s go bit by bit: 

• You’ll get more precise results. Calibration helps your robot move with pinpoint precision along its programmed path. Its joints and motors work together in harmony, allowing smooth and accurate movement.
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• Your company gets big productivity increases. A calibrated robot works at peak efficiency. It wastes no time overshooting targets or struggling with imprecise movements. This means faster cycle times and higher throughput.
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• You’ll get fewer errors. Calibration minimizes positional errors that can creep in over time and use. Your robot stays on track, avoiding faulty movements that lead to poor quality or even scrap parts.
  
  
• The robot will last longer. Regular calibration helps identify small errors early before they become big problems. This preventative maintenance helps your robot operate well for a longer period, minimizing unplanned downtime and expensive repairs.

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Common challenges in robot calibration

Robot calibration involves making adjustments so your robot works properly. 

Here are some issues you may face: 

• Backlash happens when gears have too much space between them. As the gears change direction, it takes time for the teeth to re-engage, causing lost motion. This can reduce accuracy and repeatability.
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• Hysteresis is when the robot's position depends on which direction it approached from. As materials bend and twist under stress, the robot may not return to the exact same spot. Thermal expansion means parts change size as they heat up, affecting precision.
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• Other problems include mechanical wear, electrical noise, and software bugs. Regular maintenance and testing help find and fix these challenges. Calibration reduces errors, so you get the performance you need from your robot.

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Summing up

To recap, robot calibration is an essential process that allows robots to do their jobs accurately. By calibrating a robot's tools and motions, manufacturers can fine-tune its performance and precision. 

While it may seem complicated at first, calibration just requires methodical measurements and adjustments until your bot operates just the way you want it to. 

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Next steps

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• Cost-effective innovation: Access advanced automation technology at half the price of the competition. 
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• Top-of-the-line performance: With a payload capacity of up to 18 kg and impressive speed, RO1 outperforms similar robots, delivering precision and quality results.
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• Ongoing, constant evolution: Harness the power of advanced AI comparable to GPT-4, allowing RO1 to continuously learn and adapt to your unique workflow — all within a no-programming-required, no-code framework. 
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• Safe and collaborative: RO1 is designed to integrate with your team, prioritizing safety through advanced vision and sensor technology.

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