Challenges and solutions in the robotics field

Melexis's cutting-edge sensor technologies have been meticulously developed to address the multifaceted demands of modern robotics. Leveraging extensive experience in automotive and industrial applications, Melexis's engineering teams have worked closely with the robotics market to create new core solutions tailored to the needs of both the industry and engineers. Here we explore three core robotics products, including Tactaxis® and Arcminaxis® - designed to enhance robotic sensing and control - along with Melexis's broad portfolio of sensing and driver solutions, which are also well-suited for robotics environments.
 
Tactaxis® captures 3D force data to deliver real-time tactile feedback, which is essential for both safe human-robot interaction and precise operational control. Each tactile pixel (taxel) consists of a magnet embedded in a soft elastomer material positioned above a Triaxis® 3D magnetic sensing IC. This unique configuration creates a soft contact interface that mimics attributes of human skin and delivers exceptional sensitivity, ensuring that even minimal forces generate a response.
 
The sensor's construction enables measurement of normal forces up to 5 N and shear forces up to 2 N with impressive accuracy at the sensor level. A force resolution of 30 mN allows robots to detect weight changes as slight as 3 grams, enhancing their ability to perceive subtle force variations and dynamically adjust grip and manipulation. Additionally, although with reduced accuracy, the sensor accommodates an extended force range up to 15 N. This overhead helps address scenarios in uncontrolled environments where temporary impacts or collisions may occur, as well as situations where robotic systems may experience high transient forces beyond typical operating ranges. The sensor can also adapt to various physical shapes; for example, configuring sensors into arrays enables complex surfaces or multi-fingered robotic hands to be equipped with a unified tactile sensing network.
 
Beyond 3D sensing functionality and scalability, Tactaxis® is engineered for practical integration. Measuring just 6 x 6 x 4.4 mm³, the highly compact taxels are ideal for confined spaces, and their gradiometric approach eliminates errors caused by stray magnetic fields. Furthermore, the design's inherent robustness, combined with an operating temperature range of -20°C to 85°C, ensures reliable performance across diverse environments. Moreover, unlike alternative optical technologies, the Tactaxis® sensor features a fully integrated design and semiconductor fabrication process that enables high-volume production of factory-calibrated sensors, resulting in significant cost reductions and reliability improvements.

At the heart of many robotic applications lies the critical need for precise and reliable motion control. Melexis developed Arcminaxis® to address this challenge, offering advanced position and speed sensing capabilities that help robots operate with exceptional precision while reducing the costs and integration complexities typically associated with rotary encoders.
 
Arcminaxis® leverages Melexis's patented Triaxis® technology, integrating a unique dual-track magnet design and innovative on-chip calibration to achieve 18-bit resolution across a full 360° range - capturing even the most minute positional changes with outstanding repeatability. This groundbreaking technology employs a Vernier-type magnet configuration consisting of a Master track and a Nonius track to measure two orthogonal magnetic field components: axial and tangential.
 
The system utilizes four distinct signals and sophisticated algorithms to effectively reduce crosstalk from the master track, enabling precise Nonius angle extraction. Arcminaxis® further minimizes harmonic distortions resulting from mechanical misalignments such as eccentricity and residual magnetic interference, while a Look-Up Table (LUT) compensates for non-linearity caused by magnet imperfections. This multi-axis sensing system and advanced signal processing enable flexible assembly, with a placement tolerance of ±0.5 mm between the magnet and sensor, along with the ability to accommodate larger magnetic poles and a 1.5 mm air gap. For engineers concerned with robotic design assembly and scalability, the inherent flexibility of Arcminaxis® significantly reduces mechanical complexity, simplifies production processes, improves long-term reliability, and offers a more cost-effective solution compared to conventional high-performance optical sensors.
 
The first product in the Arcminaxis® range, the MLX90384, is housed in a compact TSSOP-16 package and comes complete with an integrated magnet and a software suite featuring a dedicated calibration routine. Its pitch-independent design eliminates the need for precise magnet-sensor matching, while a high-speed 6 MHz SPI interface supports accurate acquisition of angular position, speed, and rotation data, along with error detection and in-situ calibration. The MLX90384 solution is also available as part of a ready-to-run evaluation kit, preassembled, pre-calibrated, and equipped with a pre-programmed microcontroller, allowing engineers to quickly assess this advanced technology.

Beyond its core robotics solutions, Melexis offers a comprehensive portfolio of sensing Integrated Circuits (ICs) that can assist engineers in designing next-generation robotic systems. This portfolio includes components such as position sensors, temperature sensors, current sensors, and latch & switch ICs - each designed to address the unique challenges of modern robotics.
 
Position feedback is fundamental to safe and accurate robotic movement, and Melexis provides a wide range of position sensing IC solutions based on both its magnetic and inductive technologies. Position sensors enhance control; the Triaxis® Hall technology series is suitable for a wide variety of robotic systems, offering performance- and value-optimized solutions, including the Triaxis® Resolver, Triaxis® Encoder, and Linear Hall product families. Unlike traditional Hall sensors, which only measure magnetic flux perpendicular to their surface, Triaxis® sensors employ patented technology to measure all three magnetic flux components (BX, BY, and BZ) within a single IC.
 
As an alternative, or as part of a combined heterogeneous sensing deployment, Melexis also offers a selection of inductive position sensors, resolvers, and encoders. Melexis inductive position sensor ICs are designed for rotary and long-stroke linear applications (up to 30 cm), making them ideal for industrial automation, particularly actuators. Featuring robust construction, they deliver highly accurate, real-time performance while remaining immune to electromagnetic interference and thermal drift. With flexible outputs, they are engineered for seamless integration into a variety of robotic systems, providing reliability and precision for both manufacturers and end users. Melexis's inductive portfolio also includes analog inductive resolvers. These ICs deliver high-accuracy rotational feedback (±0.36° electrical) for high-speed electric motors, operating at up to 240,000 electrical rpm while remaining immune to stray magnetic fields (per ISO 11452-8 standards).
 
Temperature monitoring is vital not only for a robot's internal health but also for ensuring environmental safety. From robotic joint monitoring to off-board charging, Melexis temperature sensors are engineered for diverse robotic deployments where precise temperature management is critical. The portfolio includes highly accurate single-point thermometers, such as plug-and-play digital infrared thermometers in TO-can packages, as well as advanced infrared sensor arrays. Melexis thermal imager ICs measure object temperatures ranging from -40°C to 300°C with typical accuracy of ±1°C across the range. Their 32x24 pixel arrays can also be used for sophisticated AI-backed operations such as person and gesture recognition, providing a cost-effective and accurate means of improving robotic navigation and guidance.
 
Efficient power management is a cornerstone of advanced robotics. Melexis current sensors provide engineers with critical insights into energy consumption patterns - both within robots and in supporting charging and power systems - enabling them to optimize performance and reduce overall power wastage. Whether power monitoring needs are simple or complex, Melexis offers suitable sensors. The portfolio ranges from conventional Hall and shunt sensors to innovative IMC-Hall, coreless integrated, and coreless external primary sensors, with each model offering distinct functionality well suited for various robotics applications.
 
Melexis also provides a range of supporting ICs that enhance robotic system performance. Its lighting driver ICs, including the innovative MeLiBu technology, enable dynamic, energy-efficient visual indicators that enhance human-robot interaction by signaling operational status, errors, or mode transitions - critical for service robots and cobots in environments where clear visual feedback is essential. Similarly, Melexis fan and pump driver ICs deliver precise control over cooling fans and fluid pumps, while its pressure sensor ICs offer accurate, real-time monitoring for pneumatic and hydraulic systems as well as environmental sensing. Together, these supporting solutions form a comprehensive portfolio that simplifies design and integration, enabling engineers to build next-generation robotic systems that are both efficient and responsive.

While artificial intelligence (AI) often dominates the headlines, the integration of new or more advanced sensing technologies is also revolutionizing the robotics field, bringing us ever closer to machines that can match the sensitivity and precision of human perception. Melexis's comprehensive sensor solutions - from the tactile sophistication of Tactaxis® to the precise positioning of Arcminaxis®, complemented by other robotics sensing IC portfolio offerings - support this transformation by helping engineers overcome integration challenges and accelerate innovation. Robotics technology will continue to converge with human ingenuity, jointly driving societal progress.