Xsens is part of the Dutch Movella group and one of the established makers of inertial sensors (IMUs) and motion-capture systems. It builds no robots. Its modules tell a robot how it is oriented in space and how fast it is turning; without that information a legged robot cannot keep its balance. For humanoids and quadrupeds the IMU is the "inner ear", as we describe in “How Does a Humanoid Robot Work”.
The datasheets show a very wide cross-section. The miniature MTi-1 is an SMD module measuring 12.1 × 12.1 × 2.55 mm and weighing 0.6 g, with a gyroscope up to 2000°/s, bias stability of 6°/h, output up to 1 kHz and UART, SPI and I²C interfaces. The MTi-630 is a small AHRS (28 × 31.5 × 13 mm, 8.9 g, IP51) with 0.2° roll and pitch accuracy and 1° heading, output up to 2 kHz. The more rugged MTi-100 and MTi-300 have an IP67 aluminium housing, a gyroscope up to 450°/s with 10°/h bias stability and update rates up to 415 Hz; the MTi-300 states 0.2° roll and pitch and 1° heading. The maker notes that both have reached end of life and are replaced by the Xsens Sirius. At the top of the scale is the MTi-680G: a water-protected (IP68) GNSS/INS with an RTK receiver, giving centimetre-level position, meant for outdoor applications.
All modules work with the MT Software Suite with SDKs in C++, C#, Python and Matlab and with ROS drivers, which makes them a convenient base for prototypes.
Why does it matter for cost and quality? A good IMU is one of the cheaper parts of a robot, but its error affects the state estimate of the whole machine. For a quadruped like the Unitree Go2 or a humanoid like the Unitree G1 the inertial sensor is part of the stabilisation loop; for navigation on mobile robots platforms and field robots in agriculture, GNSS comes in. We do not know exactly which IMUs the named robots use and we do not claim that it is Xsens. The class differences, from a 0.6 g module to an IP67 housing with hardware synchronisation, explain the price spread.
Beside the IMU, look at the other sensors we describe under Orbbec and SICK. A stationary robot, such as the cobot described in “What Is a Cobot and How Does It Differ from an Industrial Robot”, usually manages without an IMU; a mobile one needs it. Total costs are gathered in “Humanoid Robot TCO: How to Calculate Total Cost”.
In Poland we have no confirmed official Xsens distributor; purchases usually go through electronics distributors or directly from Movella. Prices are not given in the datasheets.
Products
- IMU sensors and motion capture systems for measuring robot orientation and humanoid balance
Sample specs
MTi-100: gyroscope range up to 450 deg/s, gyroscope bias stability 10 deg/h, update rate up to 415/375 Hz depending on mode (source: MTi-100.pdf).
Relevance for integrators in Poland
Market overview for Polish integrators; the company does not build its own finished robots.