Unlocking Precision and Innovation for tomorrow’s industry: The Power of IMUs

Discover how inertial measurement units (IMUs) are changing the industry by providing accurate real-time data on acceleration, angular rate and magnetic fields. How can their compact design and adaptability improve safety, efficiency and performance in different applications? What role do IMUs play in shaping the technologies of the future?

What is an IMU?

An Inertial Measurement Unit (IMU) is an electronic device that uses accelerometers, gyroscopes, and sometimes magnetometers to measure the force, angular rate, and orientation of an object.

Accelerometers measure linear acceleration along the three orthogonal axes of the device, whereas gyroscopes measure angular velocity around the same axes. Magnetometers, on the other hand, measure the strength and direction of the magnetic field, which can be used for orientation estimation.

Where can IMUs be found?

Many areas use IMUs. They can be used to track the position, orientation and movement of vehicles and aircraft, to stabilise drones and other unmanned vehicles and to monitor the movements of athletes.

In aerospace, the measuring devices are used to provide navigation information for the flight control system. In robotics, IMUs are used for motion planning, control and analysis. In areas with weak signals, such as tunnels, IMUs are a valuable addition to GPS devices. In sports, IMUs can be used to measure the movements of athletes in order to optimise performance and prevent injuries. IMUs are becoming increasingly common in consumer electronics as well, including smartphones and gaming controllers, where they can be used for motion sensing and virtual reality applications.

Why are they important?

IMUs are central to providing accurate data on specific acceleration, angular velocity and magnetic fields that enable orientation estimation and motion tracking. Their compactness and light weight enable seamless integration into existing systems. Another advantage is that they can be used in a wide range of environments, including high vibration and extreme temperature conditions. IMUs provide real-time data that was previously difficult or impossible to obtain, improving safety, efficiency and performance. As the technology evolves, its importance will continue to grow and shape a dynamic future.

Here are just a few applications where IMUs play a main role:

In aerospace, IMUs are used to provide navigation information to the flight control system, allowing aircrafts to maintain their course and stability. They are also used in spacecraft to provide guidance and control during space missions.

In robotics, IMUs are used for motion planning and control, allowing robots to move and interact with their environment with greater accuracy and precision. They can also be used in exoskeletons to provide balance and stability to the wearer.

IMUs are used in navigation systems for land, air, and sea vehicles, providing real-time information on the vehicle's position, speed, and direction of travel.

In sports, IMUs are used to measure the movements of athletes during training and competitions, helping coaches to optimize their performance and prevent injuries. They can be used to measure everything from running gait to golf swings.

Why do IMUs need calibration?

A major disadvantage of using IMUs for navigation is that they typically suffer from accumulated error. Because the guidance system is continually integrating acceleration with respect to time to calculate velocity and position (see dead reckoning), any measurement errors, however small, are accumulated over time.

General conditions that can (negatively) influence the sensor behaviour

Various factors - internal to the sensor as well as environmental conditions - can influence the behaviour of the IMUs and possibly falsify the measurement result. Particular attention should be paid to the following sources of error:

• offset error: this error can be split between stability performance (drift while the sensor remains in invariant conditions) and repeatability (error between two measurements in similar conditions separated by varied conditions in between)
• scale factor error: errors on first order sensitivity due to non repeatabilities and nonlinearities 
• misalignment error: due to imperfect mechanical mounting
• cross axis sensitivity: parasitic measurement induced by solicitation along an axis orthogonal to sensor axis 
• noise: dependent on desired dynamic performance
• environment sensitivity: primarily sensitivity to thermal gradients and accelerations

With a calibration the deviation of the sensors can be determined and corrected accordingly.

How can SPEKTRA assist you with your IMUs?

Fact 1: Especially complex inertial measurement units (IMU) combining several acceleration and angular rate sensors must be calibrated regularly to ensure reliable measurements.

Fact 2: Last year, SPEKTRA calibrated more than 7000 IMUs with the highest measuring accuracy. These include the following types: Kistler DTI 5002, OXTS RT100x-400x, ASC IMU7xxx and many more.

Whether in the automotive sector for crash or driving dynamics tests, in the fields of railway, aviation or shipping, or in the construction industry for condition monitoring – IMUs and angular rate sensors are used in a wide range of applications.

We provide calibration services at the highest level and with in-house systems for your sensors. What are your benefits?

• Service in accredited laboratory
• Modern, in-house technology 
• Highest possible measurement accuracy
• Traceable for reproducible measurements 
• Short processing time in our laboratory
• Express calibration is possible

Conclusion

Overall, the versatility and accuracy of IMUs make them an essential tool for a range of industries and applications. As technology continues to advance, it's likely that IMUs will play an increasingly important role in the way we navigate and interact with the world around us.

SPEKTRA is with you along the way – keeping your IMU’s performance accurate and reliable.

Do you have any questions about our solutions? Contact our experts. Phone: +49 351 400 24 0 | Email: sales@spektra-dresden.co