Mastering INS: A Complete Handbook for Autonomous Navigation Solutions

For modern enterprises looking to integrate inertial navigation systems (INS) into their overall business operations, grasping the core components and operational mechanisms of INS is indispensable. In the realm of inertial navigation and inertial measurement units (IMUs), three elements stand out as critical: hardware, firmware, and implementation. Below is a breakdown of the fundamentals of inertial systems tailored for contemporary businesses.

Hardware: This entails striking a balance between sensor quality, quantity, and cost—key considerations for any INS deployment.

Firmware: Encompassing data filtering, fusion, and processing, firmware is pivotal to ensuring INS accuracy and high performance. Notably, firmware solutions are not standardized across manufacturers.

Implementation: Often overlooked yet arguably the most crucial aspect of selecting an INS, implementation encompasses documentation quality and support expertise. These factors can be the deciding difference between launching a product on schedule and within budget.

Core Functionality of INS

Inertial navigation systems compute the position of devices relative to specific reference points or fixed coordinates. Within robotics and automation, INS implementations regulate roll and pitch, while continuously monitoring and maintaining heading, position, and speed. Achieving this requires seamless collaboration across multiple components to build functional autonomous robotics and navigation systems.

For a robotic system to operate autonomously, it must possess clear awareness of its current location, orientation, target destination, and navigation path. This all begins with the hardware components.

Key Components of Inertial Navigation Systems

An INS comprises three fundamental components:

Hardware

Firmware or software

Implementation

Each of these elements should be carefully evaluated when selecting an INS that aligns with a product’s specific requirements.

INS Hardware for Autonomous Systems

The hardware that powers autonomous navigation via INS typically includes some or all of the following components:

INS Sensors

Accelerometers measure the acceleration and relative speed of the device they are installed in. By tracking changes in velocity and acceleration, these sensors play a vital role in determining the device’s position at various intervals.

Gyroscopes are physical sensors that detect the angular position and motion of an object or device relative to a specific inertial reference frame. They are essential for pinpointing the exact attitude of devices in relation to other reference points and inertial frames.

Magnetometers detect magnetic fields, serving as navigational reference points for devices, robots, and complex systems.

GPS receivers, which connect to the Global Navigation Satellite System (GNSS), supplement the inertial system with additional positional data. Antennas may be integrated to enhance the autonomous system’s access to the GNSS network.

A microprocessor runs the necessary firmware for system operation. Internal storage devices can optionally log the system’s movements, locations, and activities during operation.

Form Factor

Devices are typically engineered for either protected or rugged environments. In settings where sensors can be shielded from external conditions, caseless designs are available to minimize footprint. For applications like drones, which operate in harsh conditions, ruggedized aluminum enclosures are standard.

Inertial Measurement Units (IMUs) integrate micro-electromechanical systems (MEMS), gyroscopes, magnetometers, and accelerometers into a single, user-friendly device for managing robotic navigation. An Attitude and Heading Reference System (AHRS) builds on IMU functionality by adding the ability to detect and respond to the robotic system’s attitude relative to fixed reference points. The GPS antenna supplies satellite data to enable navigation capabilities. Additionally, dual-compassing units are available to mitigate magnetic interference during heading acquisition, enabling faster calibration and quicker system startup. Together, these components—IMU, AHRS, and GNSS—constitute a complete inertial navigation system (INS).

Selecting Cost-Effective Inertial Measurement Units

When procuring hardware for inertial navigation systems, several factors significantly influence the cost and effectiveness of IMUs:

Fiber-optic gyroscopes reduce the number of sensors needed for precise readings but come with a substantial price premium—sometimes as much as 100 times higher than conventional alternatives. High-quality gyroscopes and other hardware components enhance accuracy and minimize drift.

Cost-effective combinations of accelerometers, gyroscopes, GPS systems, and magnetometers often deliver sufficient navigational performance for systems operating in enclosed environments or those with modest precision requirements. Data from these sensors is combined to compensate for individual sensor errors—a phenomenon known as sensor fusion (detailed below). In this case, the combined performance exceeds the sum of individual components.

For most enterprises, this mix of affordable sensors strikes the right balance between performance and cost. Identifying the optimal equilibrium ensures the deployment of cost-efficient IMUs tailored to the company’s unique needs.

Inertial Navigation Firmware

INS firmware comprises two core elements:

Sensor fusion firmware transmits data from all hardware sensors to the processing unit, formatting it for compatibility with the device’s microprocessor.

The Kalman filter is critical for ensuring sensor data accuracy but is not always included with sensor purchases. When provided, it is typically a proprietary program customized to the specific hardware configuration and manufacturer. Kalman filters eliminate extraneous data (referred to as “noise”), optimizing computing resource utilization for autonomous navigation.

Key factors in effective data filtering include data collection and transmission methods, as well as thorough documentation—particularly during initial implementation—to identify areas for improvement. User-friendly interfaces and real-time data visualization speed also contribute to overall project success.

INS Implementation

INS implementation typically demands the greatest investment in resources and time. Key components of this process include the following phases:

INS Scoping Phase

Evaluating available INS solutions on the market

Determining the sensor types required for the autonomous navigation project

Assessing the inertial navigation provider’s ability to deliver desired outcomes

INS Implementation Process

Completeness and quality of sensor and firmware documentation

Expertise and availability of sensor support teams

Compatibility between the desired system and sensor capabilities

Integration of the control system with sensor data

Thorough research and scoping of these factors are essential when selecting an INS manufacturer. Ideally, the chosen sensor will offer the right hardware, firmware, and implementation support—all within a cost structure that ensures the autonomous robotic system is both high-performing and profitable. This sets the stage for a brief introduction to our solutions at Inertial Sense.

Inertial Sense: Your Partner in Autonomous Navigation

At Inertial Sense, we specialize in delivering optimal, practical solutions for autonomous navigation needs. Our offerings include key features designed to streamline implementation and maximize results:

INS Hardware

Our INS sensors boast an unrivaled footprint-to-performance ratio. Reliable and precise, they are compact enough to fit on a dime.

INS Firmware

Our Kalman filter, refined over a decade, delivers near-error-free data, ensuring devices stay on course with minimal drift.

Our proprietary sensor fusion solution enables integration with a wide range of sensors—including those not manufactured by us.

INS Implementation

We provide an integrated evaluation tool that allows real-time troubleshooting and error correction of data, as well as performance assessment of individual sensors. This saves time and effort in verifying system accuracy during operation.

Our dedicated software development kit (SDK) is regularly updated, featuring an intuitive interface and comprehensive documentation. Clients receive free access to the latest updates and are kept informed of ongoing improvements.

At Inertial Sense, we take pride in offering the industry’s simplest, most convenient implementation processes. We collaborate closely with clients to provide the necessary training and support for a seamless experience.

Our documentation is free of technical jargon, removing barriers to rapid adoption of our autonomous navigation systems. Additionally, we offer live human support with screen-sharing capabilities and fast response times, ensuring clients can connect with a real expert when assistance is needed.