Buying vs Building an IMU
In today’s precision-driven world, motion sensing is a necessity, embedded at the heart of modern technology. Inertial measurement units (IMUs) enable critical functions across a wide range of systems, stabilising autonomous drones, supporting underwater navigation where GPS is unavailable, compensating for aircraft motion in aerial surveys, and guiding robotic arms in automated manufacturing. They are fundamental in many industries where precise motion sensing, stabilisation, guidance, navigation, and pointing are needed.
Given the crucial role of IMUs, engineers face a critical decision: should they buy an IMU for their project, or build one?
The Temptation to Build
For any engineering team, the prospect of developing an IMU is attractive at first. Gyroscopes and accelerometers are readily available, development boards are inexpensive, much of the necessary software is open-source, and PCB fabrication can be done quickly. The argument typically begins with anticipated cost savings. Why invest thousands in a high-end IMU when individual sensors are available for a fraction of the price? In theory, pairing these sensors with a microcontroller and software could create a functional in-house IMU.
One advantage of building an IMU is the freedom to mix sensors from different suppliers to tailor the solution to specific requirements. This design flexibility enables custom performance profiles which may not be achievable with off-the-shelf units. However, this flexibility comes with the challenge of integrating and coordinating multiple suppliers, potentially impacting project schedules.
Furthermore, achieving low bias instability, high scale factor accuracy, and robust temperature performance is not just difficult, it is capital-intensive. Proper calibration demands not only advanced expertise in sensor fusion algorithms and precision tuning but also access to high-end equipment. This includes precision turntables, thermal chambers, and vibration test systems, each requiring a significant financial investment. Moreover, the installation and operation of such equipment come with additional complexity: facilities must be properly isolated from building-induced vibrations and environmental noise, often requiring decoupling from structural elements. Without these measures, reliable calibration and qualification across parameters such as thermal cycling, mechanical shock, vibration, and long-term drift, become unachievable. Therefore, constructing an IMU is not a simple assembly task; it is a complex engineering project demanding time, specialised equipment, and refinement. While this may be appropriate for research or academic exploration, it is rarely viable for most commercial or defence companies.
Where building is the right path, reputable suppliers such as Silicon Sensing offer a broad portfolio of accelerometers and gyroscopes to support bespoke IMU development, providing a solid foundation for those determined to pursue a custom solution. Working with a single supplier provides not only logistical simplicity but also product cohesion where gyroscopes and accelerometers are designed to complement one another in performance and interface characteristics, ensuring predictable integration. This reduces the friction and risk typically associated with sensor interoperability. More importantly, established sensor manufacturers can offer expert support, proven design practices, and an understanding of the full system lifecycle, from specification and calibration to environmental qualification. For projects requiring custom IMU development, this depth of knowledge can be the difference between a successful program and endless research and development.
The Option to Purchase
Purchasing a commercial IMU offers a straightforward and time-efficient path to deployment. For many engineering teams, integrating a ready-made IMU into their system eliminates the need to develop complex calibration routines, construct custom test setups, or manage component-level integration across multiple sensor suppliers. As a result, valuable engineering resources can be reallocated towards system-level development and performance optimisation, rather than being consumed by sensor characterisation and calibration. This frees up time and allows teams to focus on delivering core functionality and project objectives. While described as ‘commercial’, such IMUs are frequently used in defence, aerospace, and other high-reliability domains where consistency, predictability, and time-to-deployment are critical.
Purchasing an IMU, particularly those from experienced manufacturers, benefit from years of internal development and refinement. Devices such as the DMU41, incorporate a tightly integrated sensor suite that has been optimised at the system level for low bias instability, consistent scale factor, and temperature resilience. Each unit undergoes thorough calibration and qualification in controlled environments prior to shipment, ensuring repeatable performance across a range of conditions. For end users, this translates into reduced need for additional verification or correction during integration.
However, for some, purchasing an IMU may impose constraints on the configurability of the unit. While performance is typically repeatable, users are occasionally restricted to fixed interfaces, data update rates, and environmental envelopes defined by the manufacturer. It is therefore important to carefully consider both performance and configurability when selecting an IMU, particularly in applications with unique operational requirements or where system architecture demands specific sensor configurations or data handling logic. In such cases, an off-the-shelf IMU needs to not only meet the SWAP-C requirements, but also the performance, interface, and functional requirements, to be viable. This is where solutions such as the DMU41 can be an attractive option.
Nonetheless, for many applications, particularly those in industrial, commercial, or autonomous systems where performance must be consistent, and development timelines are fixed, purchasing an IMU is appropriate approach.
By choosing to purchase an IMU, the end user bypasses extensive research and development, lengthy manufacturing processes, and complex per-unit calibration cycles. This choice is not solely about convenience; it reduces technical and financial risk while ensuring predictable system integration. Crucially, it enables the customer to focus on delivering value to their own end users, accelerating deployment, improving reliability, and strengthening their ability to meet operational demands.
To Buy or to Build…
Ultimately, the decision to buy or build a MEMS IMU must be driven by practical considerations. If an organisation’s mission is to improve inertial sensing technology or integrate the IMU into a system demanding absolute design freedom, then building may be the correct choice. However, if the objective is to deliver a reliable, high-performance product to market while controlling costs and minimising delays and risk, then purchasing a field-proven solution is the rational choice. Regardless of the choice, working with a supplier that provides accelerometers, gyroscopes, and IMUs offers an attractive proposition for both buying and building. Such a supplier can deliver product cohesion, expert support, and streamlined integration across components, ensuring better performance and reduced risk. In conclusion, most teams can build an IMU given sufficient time, capital, and specialist knowledge, but the important question remains: is it right for you?
Whichever path you choose, our team is available to discuss your requirements. Contact us at [email protected] to explore how we can support your project.
