FAQ

Common technical questions and selection guidance. Product facts come from the applicable programming manual and model-specific datasheet; general engineering guidance does not replace validation under actual operating conditions.

This page also serves as the authoritative answer source for the Polaris AI assistant; keep it consistent with the latest datasheets. Only add questions that are hard for the model to answer, missing from other site docs/PDFs, easily confused, or beginner-level — plain datasheet specs belong in the knowledge base, not here.

Q: How should I select an IMU for stable heading on an indoor AGV or robot?

First distinguish short-term relative rotation from long-term absolute heading. A 6-axis mode does not rely on a magnetometer and suits magnetically disturbed environments, but relative heading drifts over time. A 9-axis mode uses a magnetic reference that may be unreliable near steel structures, motors or changing currents. See IMU Command & Programming Manual

As a general system-design approach, establish whether wheel odometry, lidar or visual localization can provide an external reference before comparing IMU drift over the required time interval, interfaces and mounting constraints. External fusion requires system integration; this does not mean a particular model has those functions built in. Before selecting, confirm which heading or localization references the existing system already provides.

Q: How should I compare magnetic heading and GNSS heading when heading is needed at rest?

Define whether the reference is magnetic north or true north and whether heading must be available while stationary. A 9-axis IMU/AHRS heading references magnetic north and requires a stable magnetic environment and calibration. Applicable dual-antenna INS models use an antenna baseline for heading; check the exact model, installation and heading solution quality. A single antenna's course over ground is not the stationary vehicle's orientation. See IMU Command & Programming Manual and INS Command & Programming Manual

First establish GNSS conditions and the antenna baseline that can be installed, then check the accuracy conditions in the exact model's datasheet. Having a heading output alone does not establish suitability for stationary heading.

Q: Can integrated navigation maintain the same positioning accuracy through a GNSS outage?

Accuracy with GNSS/RTK aiding is not a guarantee of outage performance. Inertial dead reckoning can continue producing navigation data, but errors accumulate with outage duration and motion conditions. Working communication or continued position output does not mean accuracy is unchanged. See INS Command & Programming Manual

A general evaluation should first establish the longest continuous outage and the allowable error during it, then account for speed, trajectory, antenna installation and available aiding. Support for wheel odometry or other aiding must be confirmed for the exact model and delivery configuration. With a defined error target or a planned sample evaluation, contact sales or an application engineer to define the test conditions together.

Q: Can I select a sensor for vibration or sustained acceleration using static attitude accuracy alone?

Static accuracy alone is insufficient. As a general engineering principle, motion-induced acceleration, vibration, mounting, bandwidth and latency affect attitude measurement. A higher output rate does not establish higher dynamic accuracy. Define the operating conditions first, then compare error and latency against a known attitude reference under representative mounting and motion conditions.

Check performance values and their test conditions in the exact model's datasheet; verify coordinate systems and installation orientation in the applicable manual. Returning the sensor to level after motion is a qualitative check, not a measurement of dynamic accuracy throughout the motion. Product datasheets and IMU Command & Programming Manual

Q: What should I check when integrating with an existing controller or localization system?

Determine whether the host needs acceleration/angular rate, fused attitude or navigation results. Then check electrical interfaces, protocols, output rate, time synchronization, coordinate systems and mounting space. Similar interface names do not imply electrical compatibility: TTL and RS-232 require appropriate conversion. Do not infer interface support across model suffixes. For a new CAN integration, evaluate J1939 first and confirm support for the exact model and delivery configuration. See IMU Command & Programming Manual and INS Command & Programming Manual

Once the host platform is known, use Software & Development to find existing SDKs and examples. System-level fusion and customer-code integration still require validation; an example does not establish that a complete project is supported.

Q: How should I set up the output of an IMU/AHRS used with ROS?

First declare how the module sits on the vehicle with the mounting orientation, then choose the output data axes. With ROS selected (CONFIG IMU COORD 4, then save and reboot; in CHCenter, choose it under "Output Data Axes" on the "Work Mode" page of the configuration dialog), the data follow the ROS REP-103 convention: X toward the vehicle front, Y left, Z up, and the official ROS driver publishes them with frame_id set to base_link, with no extra TF. Heading is counter-clockwise positive: 0 with the nose pointing east in 9-axis mode, 0 at power-on in 6-axis mode; pitch is positive nose down. Keeping the default Right-Front-Up needs a static TF rotated −90° about Z. See IMU Command & Programming Manual "Output Data Axes" and the ROS driver notes

Q: How do I get a firmware upgrade?

To prevent incorrect flashing and version mix-ups, this site does not provide firmware downloads. To upgrade, contact technical support with the product model, the current firmware version (query it with LOG VERSION on serial products) and the problem you want to address; support will confirm the applicable firmware file.

The applicable manual describes how to query the version and upgrade with CHCenter. Do not use another model's firmware on the device. IMU Command & Programming Manual and INS Command & Programming Manual